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Sample records for ground potential surface

  1. Potential Energy Surfaces of Nitrogen Dioxide for the Ground State

    Institute of Scientific and Technical Information of China (English)

    SHAO Ju-Xiang; ZHU Zheng-He; CHENG Xin-Lu; YANG Xiang-Dong

    2007-01-01

    The potential energy function of nitrogen dioxide with the C2v symmetry in the ground state is represented using the simplified Sorbie-Murrell many-body expansion function in terms of the symmetry of NO2. Using the potential energy function, some potential energy surfaces of NO2(C2v, X2A1), such as the bond stretching contour plot for a fixed equilibrium geometry angle θ and contour for O moving around N-O (R1), in which R1 is fixed at the equilibrium bond length, are depicted. The potential energy surfaces are analysed. Moreover, the equilibrium parameters for NO2 with the C2v, Cs and D8h symmetries, such as equilibrium geometry structures and energies, are calculated by the ab initio (CBS-Q) method.

  2. The Effect of Images on Surface Potential and Resistance Calculation of Grounding Systems

    Directory of Open Access Journals (Sweden)

    MARTINS, A.

    2015-05-01

    Full Text Available In the grounding systems with a two layers soil, the calculation of the surface potential using the image method is sometimes impossible due to singularities, avoiding researchers to use the method for electrodes in the bottom layer. In the literature this problem solution is refereed as unreliable or solved with other more complex methods. This paper presents a new approach to calculate the surface potentials in a two. layer soil, for electrodes in the bottom layer, when images are at surface. The singularities in computing surface voltage, when the first image upwards lies at surface, are analysed and it's shown that a small change in top layer thickness allows an approximate solution. Surface potentials due to grid conductor are also considered and the values of resistance are compared with those from other methodologies. Singularities for a ground rod that crosses the two layers are also treated. The obtained values of resistance are not satisfactory, due to lower segments images that overlap the upper segments. This paper also proposes shifting the surface of the upper part of the ground rod, in the upper layer, or taking the modulus of the mutual resistance, to overcome this difficulty.

  3. The Potential Energy Surface for the Electronic Ground State of H 2Se Derived from Experiment

    Science.gov (United States)

    Jensen, P.; Kozin, I. N.

    1993-07-01

    The present paper reports a determination of the potential energy surface for the electronic ground state of the hydrogen selenide molecule through a direct least-squares fitting to experimental data using the MORBID (Morse oscillator rigid bender internal dynamics) approach developed by P. Jensen [ J. Mol. Spectrosc.128, 478-501 (1988); J. Chem. Soc. Faraday Trans. 284, 1315-1340 (1988)]. We have fitted a selection of 303 rotation-vibration energy spacings of H 280Se, D 280Se, and HD 80Se involving J ≤ 5 with a root-mean-square deviation of 0.0975 cm -1 for the rotational energy spacings and 0.268 cm -1 for the vibrational spacings. In the fitting, 14 parameters were varied. On the basis of the fitted potential surface we have studied the cluster effect in the vibrational ground state of H 2Se, i.e., the formation of nearly degenerate, four-member groups of rotational energy levels [see I. N. Kozin, S. Klee, P. Jensen, O. L. Polyansky, and I. M. Pavlichenkov. J. Mol. Spectrosc., 158, 409-422 (1993), and references therein]. The cluster formation becomes more pronounced with increasing J. For example, four-fold clusters formed in the vibrational ground state of H 280Se at J = 40 are degenerate to within a few MHz. Our predictions of the D 280Se energy spectrum show that for this molecule, the cluster formation is displaced towards higher J values than arc found for H 280Se. In the vibrational ground state, the qualitative deviation from the usual rigid rotor picture starts at J = 12 for H 280Se and at J = 18 for D 280Se, in full agreement with predictions from semiclassical theory. An interpretation of the cluster eigenstates is discussed.

  4. Spectroscopic determination of ground and excited state vibrational potential energy surfaces

    Science.gov (United States)

    Laane, Jaan

    Far-infrared spectra, mid-infrared combination band spectra, Raman spectra, and dispersed fluorescence spectra of non-rigid molecules can be used to determine the energies of many of the quantum states of conformationally important vibrations such as out-of-plane ring modes, internal rotations, and molecular inversions in their ground electronic states. Similarly, the fluorescence excitation spectra of jet-cooled molecules, together with electronic absorption spectra, provide the information for determining the vibronic energy levels of electronic excited states. One- or two-dimensional potential energy functions, which govern the conformational changes along the vibrational coordinates, can be determined from these types of data for selected molecules. From these functions the molecular structures, the relative energies between different conformations, the barriers to molecular interconversions, and the forces responsible for the structures can be ascertained. This review describes the experimental and theoretical methodology for carrying out the potential energy determinations and presents a summary of work that has been carried out for both electronic ground and excited states. The results for the out-of-plane ring motions of four-, five-, and six-membered rings will be presented, and results for several molecules with unusual properties will be cited. Potential energy functions for the carbonyl wagging and ring modes for several cyclic ketones in their S1(n,pi*) states will also be discussed. Potential energy surfaces for the three internal rotations, including the one governing the photoisomerization process, will be examined for trans-stilbene in both its S0 and S1(pi,pi*) states. For the bicyclic molecules in the indan family, the two-dimensional potential energy surfaces for the highly interacting ring-puckering and ring-flapping motions in both the S0 and S1(pi,pi*) states have also been determined using all of the spectroscopic methods mentioned above

  5. The potential surface in the ground electronic state of HCP with the isomerization process: the validity of calculating potential surface with DFT methods

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The density functional theory (DFT) provides us an effective way to calculate large cluster systems with moderate computational demands. We calculate potential energy surfaces (PES) with several different approaches of DFT. The PES in the ground electronic state are related to HCP's isomerization process. The calculated PES are compared with the “experimental” PES obtained by fitting from the experimental vibrational spectra and that given by the “accurate” quantum chemistry calculation with more expensive computations. The comparisons show that the potential surfaces calculated with DFT methods can reach the accuracy of less than 0.1 eV.

  6. [Heavy metals in the surface sediment of the dumping ground outside Jiaozhou Bay and their potential ecological risk].

    Science.gov (United States)

    Cao, Cong-hua; Zhang, Nai-xing; Wu, Feng-cong; Sun, Bin; Ren, Rong-zhu; Sun, Xu; Lin, Sen; Zhang, Shao-ping

    2011-05-01

    Based on the monitoring data of heavy metals (Cr, Hg, Cd, Pb, Zn, Cu) in the surface sediment of the dumping ground outside Jiaozhou Bay from 2003 to 2008, the distribution patterns, factors controlling the distribution, and the potential ecological risks of heavy metals were studied with the data in 2007-08, and the fluctuation trends of heavy metals in the surface sediment over the 6 years were also discussed. The average concentrations of heavy metals Cr, Hg, Cd, Pb, Zn, Cu in the surface sediment were 29.47, 0.065, 0.105, 1.145, 9.63, 3.355 microg/g, respectively. Except for Cr, the concentration of heavy metals was high in the central dumping area while low outside the dumping ground, suggesting that the dredged material dumped was the main source of heavy metals. Organic carbon content in the surface sediment had a significant positive correlation with heavy metals except for Cr. Based on the results of ecological risk assessment, Hg had a medium potential ecological risk, while the other heavy metals had low potential ecological risk. The overall risk index (RI) of the heavy metals was 100.50, which was considered as a level of low potential ecological risk. The average concentration of heavy metals showed a decreasing trend over the 6 years, except Hg. In conclusion, the quality of surface sediment in term of heavy metals in the dumping ground outside Jiaozhou Bay is relatively good.

  7. Ab initio ground state phenylacetylene-argon intermolecular potential energy surface and rovibrational spectrum

    DEFF Research Database (Denmark)

    Cybulski, Hubert; Fernandez, Berta; Henriksen, Christian

    2012-01-01

    We evaluate the phenylacetylene-argon intermolecular potential energy surface by fitting a representative number of ab initio interaction energies to an analytic function. These energies are calculated at a grid of intermolecular geometries, using the CCSD(T) method and the aug-cc-pVDZ basis set ...

  8. Vibrational Spectra and Potential Energy Surface for Electronic Ground State of Jet-Cooled Molecule S2O

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Yan; DING Shi-Liang

    2004-01-01

    The vibration states of transition molecule S2O, including both bending and stretching vibrations, are studied in the framework of dynamical symmetry groups U1(4) U2(4). We get all the vibration spectra of S2O by fitting 22 spectra data with 10 parameters. The fitting rms of the Hamiltonian is 2.12 cm-1. With the parameters and Lie algebraic theory, we give the analytical expression of the potential energy surface, which helps us to calculate the dissociation energy and force constants of S2O in the electronic ground state.

  9. A semiempirical study of the optimized ground and excited state potential energy surfaces of retinal and its protonated Schiff base

    Science.gov (United States)

    Parusel, A. B.; Pohorille, A.

    2001-01-01

    The electronic ground and first excited states of retinal and its Schiff base are optimized for the first time using the semiempirical AM1 Hamiltonian. The barrier for rotation about the C(11)-C(12) double bond is characterized by variation of both the twist angle delta(C(10)-C(11)-C(12)-C(13)) and the bond length d(C(11)-C(12)). The potential energy surface is obtained by varying these two parameters. The calculated ground state rotational barrier is equal to 15.6 kcal/mol for retinal and 20.5 kcal/mol for its Schiff base. The all-trans conformation is more stable by 3.7 kcal/mol than the 11-cis geometry. For the first excited state, S(1,) the 90 degrees twisted geometry represents a saddle point for retinal with the rotational barrier of 14.6 kcal/mol. In contrast, this conformation is an energy minimum for the Schiff base. It can be easily reached at room temperature from the planar minima since it is separated from them by a barrier of only 0.6 kcal/mol. The 90 degrees minimum conformation is more stable than the all-trans by 8.6 kcal/mol. We are thus able to present a reaction path on the S(1) surface of the retinal Schiff base with an almost barrier-less geometrical relaxation into a twisted minimum geometry, as observed experimentally. The character of the ground and first excited singlet states underscores the need for the inclusion of double excitations in the calculations.

  10. A new accurate ground-state potential energy surface of ethylene and predictions for rotational and vibrational energy levels

    Energy Technology Data Exchange (ETDEWEB)

    Delahaye, Thibault, E-mail: thibault.delahaye@univ-reims.fr; Rey, Michaël, E-mail: michael.rey@univ-reims.fr; Tyuterev, Vladimir G. [Groupe de Spectrométrie Moléculaire et Atmosphérique, UMR CNRS 7331, BP 1039, F-51687, Reims Cedex 2 (France); Nikitin, Andrei [Laboratory of Theoretical Spectroscopy, Institute of Atmospheric Optics, Russian Academy of Sciences, 634055 Tomsk, Russia and Quamer, State University of Tomsk (Russian Federation); Szalay, Péter G. [Institute of Chemistry, Eötvös Loránd University, P.O. Box 32, H-1518 Budapest (Hungary)

    2014-09-14

    In this paper we report a new ground state potential energy surface for ethylene (ethene) C{sub 2}H{sub 4} obtained from extended ab initio calculations. The coupled-cluster approach with the perturbative inclusion of the connected triple excitations CCSD(T) and correlation consistent polarized valence basis set cc-pVQZ was employed for computations of electronic ground state energies. The fit of the surface included 82 542 nuclear configurations using sixth order expansion in curvilinear symmetry-adapted coordinates involving 2236 parameters. A good convergence for variationally computed vibrational levels of the C{sub 2}H{sub 4} molecule was obtained with a RMS(Obs.–Calc.) deviation of 2.7 cm{sup −1} for fundamental bands centers and 5.9 cm{sup −1} for vibrational bands up to 7800 cm{sup −1}. Large scale vibrational and rotational calculations for {sup 12}C{sub 2}H{sub 4}, {sup 13}C{sub 2}H{sub 4}, and {sup 12}C{sub 2}D{sub 4} isotopologues were performed using this new surface. Energy levels for J = 20 up to 6000 cm{sup −1} are in a good agreement with observations. This represents a considerable improvement with respect to available global predictions of vibrational levels of {sup 13}C{sub 2}H{sub 4} and {sup 12}C{sub 2}D{sub 4} and rovibrational levels of {sup 12}C{sub 2}H{sub 4}.

  11. Ab initio potential energy surface and excited vibrational states for the electronic ground state of Li2H

    Institute of Scientific and Technical Information of China (English)

    鄢国森; 先晖; 谢代前

    1997-01-01

    A 285-pomt multi-reference configuration-interaction involving single and double excitations ( MRS DCI) potential energy surface for the electronic ground state of L12H is determined by using 6-311G (2df,2pd)basis set.A Simons-Parr-Finlan polynomial expansion is used to fit the discrete surface with a x2 of 4.64×106 The equn librium geometry occurs at Rc=0.172 nm and,LiHL1=94.10°.The dissociation energy for reaction I2H(2A)→L12(1∑g)+H(2S) is 243.910 kJ/mol,and that for reaction L12H(2A’)→HL1(1∑) + L1(2S) is 106.445 kl/mol The inversion barrier height is 50.388 kj/mol.The vibrational energy levels are calculated using the discrete variable representation (DVR) method.

  12. Organochlorine pesticides in surface soils from obsolete pesticide dumping ground in Hyderabad City, Pakistan: contamination levels and their potential for air-soil exchange.

    Science.gov (United States)

    Alamdar, Ambreen; Syed, Jabir Hussain; Malik, Riffat Naseem; Katsoyiannis, Athanasios; Liu, Junwen; Li, Jun; Zhang, Gan; Jones, Kevin C

    2014-02-01

    This study was conducted to examine organochlorine pesticides (OCPs) contamination levels in the surface soil and air samples together with air-soil exchange fluxes at an obsolete pesticide dumping ground and the associated areas from Hyderabad City, Pakistan. Among all the sampling sites, concentrations of OCPs in the soil and air samples were found highest in obsolete pesticide dumping ground, whereas dominant contaminants were dichlorodiphenyltrichloroethane (DDTs) (soil: 77-212,200 ng g(-1); air: 90,700 pg m(-3)) and hexachlorocyclohexane (HCHs) (soil: 43-4,090 ng g(-1); air: 97,400 pg m(-3)) followed by chlordane, heptachlor and hexachlorobenzene (HCB). OCPs diagnostic indicative ratios reflect historical use as well as fresh input in the study area. Moreover, the air and soil fugacity ratios (0.9-1.0) at the dumping ground reflecting a tendency towards net volatilization of OCPs, while at the other sampling sites, the fugacity ratios indicate in some cases deposition and in other cases volatilization. Elevated concentrations of DDTs and HCHs at pesticide dumping ground and its surroundings pose potential exposure risk to biological organisms, to the safety of agricultural products and to the human health. Our study thus emphasizes the need of spatio-temporal monitoring of OCPs at local and regional scale to assess and remediate the future adverse implications.

  13. Ab initio ground and excited state potential energy surfaces for NO-Kr complex and dynamics of Kr solids with NO impurity.

    Science.gov (United States)

    Castro-Palacios, Juan Carlos; Rubayo-Soneira, Jesús; Ishii, Keisaku; Yamashita, Koichi

    2007-04-01

    The intermolecular potentials for the NO(X 2Pi)-Kr and NO(A 2Sigma+)-Kr systems have been calculated using highly accurate ab initio calculations. The spin-restricted coupled cluster method for the ground 1 2A' state [NO(X 2Pi)-Kr] and the multireference singles and doubles configuration interaction method for the excited 2 2A' state [NO(A 2Sigma+)-Kr], respectively, were used. The potential energy surfaces (PESs) show two linear wells and one that is almost in the perpendicular position. An analytical representation of the PESs has been constructed for the triatomic systems and used to carry out molecular dynamics (MD) simulations of the NO-doped krypton matrix response after excitation of NO. MD results are shown comparatively for three sets of potentials: (1) anisotropic ab initio potentials [NO molecule direction fixed during the dynamics and considered as a point (its center of mass)], (2) isotropic ab initio potentials (isotropic part in a Legendre polynomial expansion of the PESs), and (3) fitted Kr-NO potentials to the spectroscopic data. An important finding of this work is that the anisotropic and isotropic ab initio potentials calculated for the Kr-NO triatomic system are not suitable for describing the dynamics of structural relaxation upon Rydberg excitation of a NO impurity in the crystal. However, the isotropic ab initio potential in the ground state almost overlaps the published experimental potential, being almost independent of the angle asymmetry. This fact is also manifested in the radial distribution function around NO. However, in the case of the excited state the isotropic ab initio potential differs from the fitted potentials, which indicates that the Kr-NO interaction in the matrix is quite different because of the presence of the surrounding Kr atoms acting on the NO molecule. MD simulations for isotropic potentials reasonably reproduce the experimental observables for the femtosecond response and the bubble size but do not match

  14. GROUND WATER CONTAMINATION POTENTIAL FROM STORMWATER INFILTRATION

    Science.gov (United States)

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

  15. MCSCF/CI ground state potential energy surface, dipole moment function, and gas phase vibrational frequencies for the nitrogen dioxide positive ion

    Energy Technology Data Exchange (ETDEWEB)

    Hopper, D.G.

    1980-05-01

    The ground state potential energy surface for the nitrogen dioxide positive ion, NO/sup +//sub 2/X /sup 1/..sigma../sup +//sub g/(..sigma../sup +/,A/sub 1/,A'), has been scanned with a correlated wave function to obtain directly, for the first time, the gas phase equilibrium geometry, force constants, vibrational frequencies, and dipole moment function. The wave function for this scan was constructed from a double-zeta plus polarization one-electron basis with a 12 configuration MCSCF determination of the orbital basis for a full valence /sup 1/..sigma../sup +//sub g/ configuration interaction expansion. The calculated equilibrium bond length is 1.12 A. The vibrational frequencies are computed to be ..nu../sub 1/=1514, ..nu../sub 2/=679, and ..nu../sub 3/=2614 cm/sup -1/ The present ab initio results differ significantly from crystalline spectroscopic studies and are, thus, the best values available for the gas phase vibrational frequencies. The dipole moment function is nonzero at the ..sigma../sup +/, A/sub 1/, and A' geometries included in the potential surface scan, and is obtained here to provide for the future a priori calculation of the infrared band intensities.

  16. Evaluating transmission towers potentials during ground faults

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    During ground faults on transmission lines, a number of towers near the fault are likely to acquire high potentials to ground. These tower voltages, if excessive, may present a hazard to humans and animals. This paper presents analytical methods in order to determine the transmission towers potentials during ground faults, for long and short lines. The author developed a global systematic approach to calculate these voltages, which are dependent of a number of factors. Some of the most important factors are: magnitudes of fault currents, fault location with respect to the line terminals, conductor arrangement on the tower and the location of the faulted phase, the ground resistance of the faulted tower, soil resistivity, number, material and size of ground wires. The effects of these factors on the faulted tower voltages have been also examined for different types of power lines.

  17. Shape estimation of the buried body from the ground surface potential distributions generated by current injection; Tsuryu ni yoru chihyomen den`i bunpu wo riyoshita maizobutsu keijo no suitei

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Y.; Okamoto, Y. [Chiba Institute of Technology, Chiba (Japan); Noguchi, K. [Waseda University, Tokyo (Japan); Teramachi, Y. [University of Industrial Technology, Kanagawa (Japan); Akabane, H.; Agu, M. [Ibaraki University, Ibaraki (Japan)

    1996-10-01

    Ground surface potential distribution generated by current injection was studied to estimate the shape of buried bodies. Since the uniform ground system including a homogeneous buried body is perfectly determined with the surface shape of a buried body and resistivities in/around a buried body, inversion is easy if the surface shape is described with some parameters. N electrodes are arranged in 2-D grid manner on the ground, and two electrodes among them are used for current injection, while the others for measurement of potentials. M times of measurements are repeated while changing combination of electrodes for current injection. The potential distribution measured by the mth electrode pair is represented by N-2 dimensional vectors. The square error between this distribution and calculated one is the function of k parameters on the surface shape and resistivities on a buried body. Both shape and resistivities can be estimated by solving an optimum value problem using the square error as evaluation function. Analysis is easy for a spherical body with 6 unknown parameters, however, it is difficult for more complex bodies than elliptical one or more than two bodies. 5 refs., 9 figs.

  18. Refined ab initio intermolecular ground-state potential energy surface for the He-C2H2 van der Waals complex

    DEFF Research Database (Denmark)

    Fernández, Berta; Henriksen, Christian; Farrelly, David

    2013-01-01

    , are fitted to a 15-parameter analytic function. The potential is characterised by minima of-24.21 cm-1 at distances between the rare gas atom and the C2H2 centre of mass of 4.3453 Å, and with the complex in a linear configuration. At intermediate distances the surface is rather similar to that developed...

  19. Potential structural barriers to ground-water flow, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the surface traces of regional geologic structures designated as potential ground-water flow barriers in an approximately 45,000...

  20. Potential structural barriers to ground-water flow, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the surface traces of regional geologic structures designated as potential ground-water flow barriers in an approximately 45,000...

  1. Artificial Ground Water Recharge with Surface Water

    Science.gov (United States)

    Heviánková, Silvie; Marschalko, Marian; Chromíková, Jitka; Kyncl, Miroslav; Korabík, Michal

    2016-10-01

    With regard to the adverse manifestations of the recent climatic conditions, Europe as well as the world have been facing the problem of dry periods that reduce the possibility of drawing drinking water from the underground sources. The paper aims to describe artificial ground water recharge (infiltration) that may be used to restock underground sources with surface water from natural streams. Among many conditions, it aims to specify the boundary and operational conditions of the individual aspects of the artificial ground water recharge technology. The principle of artificial infiltration lies in the design of a technical system, by means of which it is possible to conduct surplus water from one place (in this case a natural stream) into another place (an infiltration basin in this case). This way, the water begins to infiltrate into the underground resources of drinking water, while the mixed water composition corresponds to the water parameters required for drinking water.

  2. Bacteriophages as surface and ground water tracers

    Directory of Open Access Journals (Sweden)

    P. Rossi

    1998-01-01

    Full Text Available Bacteriophages are increasingly used as tracers for quantitative analysis in both hydrology and hydrogeology. The biological particles are neither toxic nor pathogenic for other living organisms as they penetrate only a specific bacterial host. They have many advantages over classical fluorescent tracers and offer the additional possibility of multi-point injection for tracer tests. Several years of research make them suitable for quantitative transport analysis and flow boundary delineation in both surface and ground waters, including karst, fractured and porous media aquifers. This article presents the effective application of bacteriophages based on their use in differing Swiss hydrological environments and compares their behaviour to conventional coloured dye or salt-type tracers. In surface water and karst aquifers, bacteriophages travel at about the same speed as the typically referenced fluorescent tracers (uranine, sulphurhodamine G extra. In aquifers of interstitial porosity, however, they appear to migrate more rapidly than fluorescent tracers, albeit with a significant reduction in their numbers within the porous media. This faster travel time implies that a modified rationale is needed for defining some ground water protection area boundaries. Further developments of other bacteriophages and their documentation as tracer methods should result in an accurate and efficient tracer tool that will be a proven alternative to conventional fluorescent dyes.

  3. Bacteriophages as surface and ground water tracers

    Science.gov (United States)

    Rossi, P.; Dörfliger, N.; Kennedy, K.; Müller, I.; Aragno, M.

    Bacteriophages are increasingly used as tracers for quantitative analysis in both hydrology and hydrogeology. The biological particles are neither toxic nor pathogenic for other living organisms as they penetrate only a specific bacterial host. They have many advantages over classical fluorescent tracers and offer the additional possibility of multi-point injection for tracer tests. Several years of research make them suitable for quantitative transport analysis and flow boundary delineation in both surface and ground waters, including karst, fractured and porous media aquifers. This article presents the effective application of bacteriophages based on their use in differing Swiss hydrological environments and compares their behaviour to conventional coloured dye or salt-type tracers. In surface water and karst aquifers, bacteriophages travel at about the same speed as the typically referenced fluorescent tracers (uranine, sulphurhodamine G extra). In aquifers of interstitial porosity, however, they appear to migrate more rapidly than fluorescent tracers, albeit with a significant reduction in their numbers within the porous media. This faster travel time implies that a modified rationale is needed for defining some ground water protection area boundaries. Further developments of other bacteriophages and their documentation as tracer methods should result in an accurate and efficient tracer tool that will be a proven alternative to conventional fluorescent dyes.

  4. Passive heating of the ground surface

    Science.gov (United States)

    Tyburczyk, Anna

    2016-03-01

    The phenomenon of phase change is one of the most important contemporary issues of thermal engineering. In particular, this applies to all kinds of heat exchanger systems, which should achieve the highest possible efficiency while reducing investment and operating costs. Some of these systems are heat pipes or thermosyphons, which, among others, are used for the heat transfer, temperature stabilization and the regulation of heat flux density. Additionally, they are passive systems, and therefore do not require an external power supply. Heat pipes can be used to stabilize the surface temperature of roads and driveways. Large heat tubes can be applied for heating the surface of bridges and overpasses, which become icy in unfavorable climatic conditions. The paper presents research on the test facility, whose main component is a long vertical copper fin. The temperature at the base of the fin was kept constant for a given series of measurements. Heat receiving fluid was ethanol at atmospheric pressure. The measurement methodology and the results of investigations were discussed. The surface temperature distribution was measured with the infrared camera, and on this basis the local values of heat flow and the heat transfer coefficient were determined. The results were presented as boiling curves for both the fin with the smooth surface and the one covered with a metal capillary-porous structure. The results obtained are useful in the design of heat exchangers, including passive heating of the ground.

  5. Passive heating of the ground surface

    Directory of Open Access Journals (Sweden)

    Tyburczyk Anna

    2016-01-01

    Full Text Available The phenomenon of phase change is one of the most important contemporary issues of thermal engineering. In particular, this applies to all kinds of heat exchanger systems, which should achieve the highest possible efficiency while reducing investment and operating costs. Some of these systems are heat pipes or thermosyphons, which, among others, are used for the heat transfer, temperature stabilization and the regulation of heat flux density. Additionally, they are passive systems, and therefore do not require an external power supply. Heat pipes can be used to stabilize the surface temperature of roads and driveways. Large heat tubes can be applied for heating the surface of bridges and overpasses, which become icy in unfavorable climatic conditions. The paper presents research on the test facility, whose main component is a long vertical copper fin. The temperature at the base of the fin was kept constant for a given series of measurements. Heat receiving fluid was ethanol at atmospheric pressure. The measurement methodology and the results of investigations were discussed. The surface temperature distribution was measured with the infrared camera, and on this basis the local values of heat flow and the heat transfer coefficient were determined. The results were presented as boiling curves for both the fin with the smooth surface and the one covered with a metal capillary-porous structure. The results obtained are useful in the design of heat exchangers, including passive heating of the ground.

  6. Radical ions with nearly degenerate ground state: correlation between the rate of spin-lattice relaxation and the structure of adiabatic potential energy surface.

    Science.gov (United States)

    Borovkov, V I; Beregovaya, I V; Shchegoleva, L N; Potashov, P A; Bagryansky, V A; Molin, Y N

    2012-09-14

    Paramagnetic spin-lattice relaxation (SLR) in radical cations (RCs) of the cycloalkane series in liquid solution was studied and analyzed from the point of view of the correlation between the relaxation rate and the structure of the adiabatic potential energy surface (PES) of the RCs. SLR rates in the RCs formed in x-ray irradiated n-hexane solutions of the cycloalkanes studied were measured with the method of time-resolved magnetic field effect in the recombination fluorescence of spin-correlated radical ion pairs. Temperature and, for some cycloalkanes, magnetic field dependences of the relaxation rate were determined. It was found that the conventional Redfield theory of the paramagnetic relaxation as applied to the results on cyclohexane RC, gave a value of about 0.2 ps for the correlation time of the perturbation together with an unrealistically high value of 0.1 T in field units for the matrix element of the relaxation transition. The PES structure was obtained with the DFT quantum-chemical calculations. It was found that for all of the cycloalkanes RCs considered, including low symmetric alkyl-substituted ones, the adiabatic PESes were surfaces of pseudorotation due to avoided crossing. In the RCs studied, a correlation between the SLR rate and the calculated barrier height to the pseudorotation was revealed. For RCs with a higher relaxation rate, the apparent activation energies for the SLR were similar to the calculated heights of the barrier. To rationalize the data obtained it was assumed that the vibronic states degeneracy, which is specific for Jahn-Teller active cyclohexane RC, was approximately kept in the RCs of substituted cycloalkanes for the vibronic states with the energies above and close to the barrier height to the pseudorotation. It was proposed that the effective spin-lattice relaxation in a radical with nearly degenerate low-lying vibronic states originated from stochastic crossings of the vibronic levels that occur due to fluctuations of

  7. Potential risk of microplastics transportation into ground water

    Science.gov (United States)

    Huerta, Esperanza; Gertsen, Hennie; Gooren, Harm; Peters, Piet; Salánki, Tamás; van der Ploeg, Martine; Besseling, Ellen; Koelmans, Albert A.; Geissen, Violette

    2016-04-01

    Microplastics, are plastics particles with a size smaller than 5mm. They are formed by the fragmentation of plastic wastes. They are present in the air, soil and water. But only in aquatic systems (ocean and rivers) are studies over their distribution, and the effect of microplastics on organisms. There is a lack of information of what is the distribution of microplastics in the soil, and in the ground water. This study tries to estimate the potential risk of microplastics transportation into the ground water by the activity of earthworms. Earthworms can produce burrows and/or galleries inside the soil, with the presence of earthworms some ecosystem services are enhanced, as infiltration. In this study we observed after 14 days with 5 treatments (0, 7, 28 and 60% w/w microplastics mixed with Populus nigra litter) and the anecic earthworm Lumbricus terrestris, in microcosms (3 replicas per treatment) that macroplastics are indeed deposit inside earthworms burrows, with 7% microplastics on the surface is possible to find 1.8 g.kg-1 microplastics inside the burrows, with a bioaumentation factor of 0.65. Burrows made by earthworms under 60% microplastics, are significant bigger (pmicroplastics in their soil surface. The amount of litter that is deposit inside the burrows is significant higher (pmicroplastics on the surface than without microplastics. The microplastics size distribution is smaller inside the burrows than on the surface, with an abundance of particles under 63 μm.

  8. Diabatic potential energy surfaces of H+ + CO

    Indian Academy of Sciences (India)

    F George D X; Sanjay Kumar

    2007-09-01

    Ab initio adiabatic and diabatic surfaces of the ground and the first excited electronic states have been computed for the H+ + CO system for the collinear ( = 0°) and the perpendicular ( = 90°) geometries employing the multi-reference configuration interaction method and Dunning's -VTZ basis set. Other properties such as mixing angle before coupling potential and before coupling matrix elements have also been obtained in order to provide an understanding of the coupling dynamics of inelastic and charge transfer process.

  9. Prediction of ground surface displacement caused by grouting

    Institute of Scientific and Technical Information of China (English)

    郭风琪; 刘晓潭; 童无期; 单智

    2015-01-01

    Ground surface displacement caused by grouting was calculated with stochastic medium theory. Ground surface displacement was assumed to be caused by the cavity expansion of grouting, slurry seepage, and slurry contraction. A prediction method of ground surface displacement was developed. The reliability of the presented method was validated through a comparison between theoretical results and results from engineering practice. Results show that the present method is effective. The effect of parameters on uplift displacement was illustrated under different grouting conditions. Through analysis, it can be known that the ground surface uplift is mainly caused by osmosis of slurry and the primary influence angle of stratum βdetermines the influence range of surface uplift. Besides, the results show that ground surface uplift displacement decreases notably with increasing depth of the grouting cavity but it increases with increasing diffusion radius of grout and increasing grouting pressure.

  10. An ab initio potential energy surface for the formic acid dimer: zero-point energy, selected anharmonic fundamental energies, and ground-state tunneling splitting calculated in relaxed 1-4-mode subspaces.

    Science.gov (United States)

    Qu, Chen; Bowman, Joel M

    2016-09-14

    We report a full-dimensional, permutationally invariant potential energy surface (PES) for the cyclic formic acid dimer. This PES is a least-squares fit to 13475 CCSD(T)-F12a/haTZ (VTZ for H and aVTZ for C and O) energies. The energy-weighted, root-mean-square fitting error is 11 cm(-1) and the barrier for the double-proton transfer on the PES is 2848 cm(-1), in good agreement with the directly-calculated ab initio value of 2853 cm(-1). The zero-point vibrational energy of 15 337 ± 7 cm(-1) is obtained from diffusion Monte Carlo calculations. Energies of fundamentals of fifteen modes are calculated using the vibrational self-consistent field and virtual-state configuration interaction method. The ground-state tunneling splitting is computed using a reduced-dimensional Hamiltonian with relaxed potentials. The highest-level, four-mode coupled calculation gives a tunneling splitting of 0.037 cm(-1), which is roughly twice the experimental value. The tunneling splittings of (DCOOH)2 and (DCOOD)2 from one to three mode calculations are, as expected, smaller than that for (HCOOH)2 and consistent with experiment.

  11. Impedance of Surface Footings on Layered Ground

    DEFF Research Database (Denmark)

    Andersen, Lars; Clausen, Johan Christian

    2005-01-01

    Traditionally only the static bearing capacity and stiffness of the ground is considered in the design of wind turbine foundations. However, modern wind turbines are flexible structures with resonance frequencies as low as 0.2 Hz. Unfortunately, environmental loads and the passage of blades past...... the tower may lead to excitation with frequencies of the same order of magnitude. Therefore, dynamic soil-structure interaction has to be accounted for in order to get an accurate prediction of the structural response. In this paper the particular problem of a rigid foundation on a layered subsoil...

  12. Impedance of Surface Footings on Layered Ground

    DEFF Research Database (Denmark)

    Andersen, Lars; Clausen, Johan

    2007-01-01

    Traditionally only the static bearing capacity and stiffness of the ground is considered in the design of wind turbine foundations. However, modern wind turbines are flexible structures with resonance frequencies as low as 0.2 Hz. Unfortunately, environmental loads and the passage of blades past...... the tower may lead to excitation with frequencies of the same order of magnitude. Therefore, dynamic soilstructure interaction has to be accounted for in order to get an accurate prediction of the structural response. In this paper the particular problem of a rigid foundation on a layered subsoil...

  13. Polyfluorinated chemicals in European surface waters, ground- and drinking waters

    NARCIS (Netherlands)

    Eschauzier, C.; de Voogt, P.; Brauch, H.-J.; Lange, F.T.; Knepper, T.P.; Lange, F.T.

    2012-01-01

    Polyfluorinated chemicals (PFCs), especially short chain fluorinated alkyl sulfonates and carboxylates, are ubiquitously found in the environment. This chapter aims at giving an overview of PFC concentrations found in European surface, ground- and drinking waters and their behavior during convention

  14. Polyfluorinated chemicals in European surface waters, ground- and drinking waters

    NARCIS (Netherlands)

    Eschauzier, C.; de Voogt, P.; Brauch, H.-J.; Lange, F.T.; Knepper, T.P.; Lange, F.T.

    2012-01-01

    Polyfluorinated chemicals (PFCs), especially short chain fluorinated alkyl sulfonates and carboxylates, are ubiquitously found in the environment. This chapter aims at giving an overview of PFC concentrations found in European surface, ground- and drinking waters and their behavior during

  15. Experimental cross-sections energy dependence and an ab initio electronic structure survey of the ground singlet potential surface for reactive Li(+) + n-C(3)H(7)Cl collisions at low energies.

    Science.gov (United States)

    Lucas, José María; de Andrés, Jaime; Albertí, Margarita; Bofill, Josep Maria; Bassi, Davide; Aguilar, Antonio

    2010-11-07

    Reactive collisions between n-C(3)H(7)Cl molecules and lithium ions both in their ground electronic state have been studied in the 0.05-7.00 eV center of mass energy range using an octopole radio frequency guided-ion beam apparatus developed in our laboratory and recently modified. At low collision energies, dehydrohalogenation reactions leading to Li(C(3)H(6))(+) and Li(HCl)(+) are the main reaction channels, while on increasing energies C(3)H(7)(+) and C(2)H(3)(+) formation become dominant. Cross section energy dependences in arbitrary units for all these reactions have been measured. Also, ab initio electronic structure calculations at the MP2 level have been performed to obtain information about the potential energy surface on which the reactive processes take place. The reactants' entrance channel leads to the formation of a stable [Li-n-C(3)H(7)Cl](+) ion-molecule adduct that, following an intrinsic-reaction-coordinate pathway and surmounting a transition state, isomerizes to [Li-i-C(3)H(7)Cl](+). From this second minimum, dehydrohalogenation reactions for both n-C(3)H(7)Cl and i-C(3)H(7)Cl share a common reaction pathway leading to the same products. All potential barriers explored by reactions always lie below the reactants' energy. The entrance reaction channel [Li-n-C(3)H(7)Cl](+) adduct also leads adiabatically to C(3)H(7)(+) formation which, on increasing collision energy generates C(2)H(3)(+)via a unimolecular decomposition. A qualitative interpretation of the experimental results based on our ab initio calculations is also given.

  16. Digital Modeling Phenomenon Of Surface Ground Movement

    Directory of Open Access Journals (Sweden)

    Ioan Voina

    2016-11-01

    Full Text Available With the development of specialized software applications it was possible to approach and resolve complex problems concerning automating and process optimization for which are being used field data. Computerized representation of the shape and dimensions of the Earth requires a detailed mathematical modeling, known as "digital terrain model". The paper aims to present the digital terrain model of Vulcan mining, Hunedoara County, Romania. Modeling consists of a set of mathematical equations that define in detail the surface of Earth and has an approximate surface rigorously and mathematical, that calculated the land area. Therefore, the digital terrain model means a digital representation of the earth's surface through a mathematical model that approximates the land surface modeling, which can be used in various civil and industrial applications in. To achieve the digital terrain model of data recorded using linear and nonlinear interpolation method based on point survey which highlights the natural surface studied. Given the complexity of this work it is absolutely necessary to know in detail of all topographic elements of work area, without the actions to be undertaken to project and manipulate would not be possible. To achieve digital terrain model, within a specialized software were set appropriate parameters required to achieve this case study. After performing all steps we obtained digital terrain model of Vulcan Mine. Digital terrain model is the complex product, which has characteristics that are equivalent to the specialists that use satellite images and information stored in a digital model, this is easier to use.

  17. Evaluation of ground stiffness parameters using continuous surface wave geophysics

    DEFF Research Database (Denmark)

    Gordon, Anne; Foged, Niels

    2000-01-01

    -small-strain stiffness of the ground Gmax. Continuous surface wave geophysics offers a quick, non-intrusive and economical way of making such measurements. This paper reviews the continuous surface wave techniques and evaluates, in engineering terms, the applicability of the method to the site investigation industry....

  18. Evaluation of ground stiffness parameters using continuous surface wave geophysics

    DEFF Research Database (Denmark)

    Gordon, Anne; Foged, Niels

    2000-01-01

    -small-strain stiffness of the ground Gmax. Continuous surface wave geophysics offers a quick, non-intrusive and economical way of making such measurements. This paper reviews the continuous surface wave techniques and evaluates, in engineering terms, the applicability of the method to the site investigation industry....

  19. Power productivity of the ground surface

    Directory of Open Access Journals (Sweden)

    Gutu A.I.

    2008-12-01

    Full Text Available Here there is presented an attempt to estimate the efficiency degree when working with soil surface through the different methods of valorization incident solar radiation. Such technical methods are being analyzed as (solar collectors, photovoltaic cells, solar thermal power plants, power cultures field (bushes, wheat, sunflower, maize, rape, sorghum as well as microalgae crops. Here is the description of advantages and disadvantages for each group in part out of these three. The technical methods are up to date from the efficiency utilization view-point of industrial area. Microalgae crops are similar to technical methods from this point of view.

  20. Uranium in US surface, ground, and domestic waters. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Drury, J.S.; Reynolds, S.; Owen, P.T.; Ross, R.H.; Ensminger, J.T.

    1981-04-01

    The report Uranium in US Surface, Ground, and Domestic Waters comprises four volumes. Volumes 2, 3, and 4 contain data characterizing the location, sampling date, type, use, and uranium conentrations of 89,994 individual samples presented in tabular form. The tabular data in volumes 2, 3, and 4 are summarized in volume 1 in narrative form and with maps and histograms.

  1. North American regional climate reconstruction from ground surface temperature histories

    Science.gov (United States)

    Jaume-Santero, Fernando; Pickler, Carolyne; Beltrami, Hugo; Mareschal, Jean-Claude

    2016-12-01

    Within the framework of the PAGES NAm2k project, 510 North American borehole temperature-depth profiles were analyzed to infer recent climate changes. To facilitate comparisons and to study the same time period, the profiles were truncated at 300 m. Ground surface temperature histories for the last 500 years were obtained for a model describing temperature changes at the surface for several climate-differentiated regions in North America. The evaluation of the model is done by inversion of temperature perturbations using singular value decomposition and its solutions are assessed using a Monte Carlo approach. The results within 95 % confidence interval suggest a warming between 1.0 and 2.5 K during the last two centuries. A regional analysis, composed of mean temperature changes over the last 500 years and geographical maps of ground surface temperatures, show that all regions experienced warming, but this warming is not spatially uniform and is more marked in northern regions.

  2. Identification of Potential Fishing Grounds Using Geospatial Technique

    Science.gov (United States)

    Abdullah, Muhammad

    2016-07-01

    Fishery resources surveys using actual sampling and data collection methods require extensive ship time and sampling time. Informative data from satellite plays a vital role in fisheries application. Satellite Remote Sensing techniques can be used to detect fish aggregation just like visual fish identification ultimately these techniques can be used to predict the potential fishing zones by measuring the parameters which affect the distribution of fishes. Remote sensing is a time saving technique to locate fishery resources along the coast. Pakistan has a continental shelf area of 50,270 km2 and coastline length of 1,120 km. The total maritime zone of Pakistan is over 30 percent of the land area. Fishery plays an important role in the national economy. The marine fisheries sector is the main component, contributing about 57 percent in terms of production. Fishery is the most important economic activity in the villages and towns along the coast, and in most of the coastal villages and settlements it is the sole source of employment and income generation. Fishing by fishermen is done on the sole basis of repeated experiments and collection of information from other fishermen. Often they are in doubt about the location of potential fishing zones. This leads to waste of time and money, adversely affecting fishermen incomes and over or under-exploitation of fishing zones. The main purpose of this study was to map potential fishing grounds by identifying various environmental parameters which impact fish aggregation along the Pakistan coastline. The primary reason of this study is the fact that the fishing communities of Pakistan's coastal regions are extremely poor and lack knowledge of the modern tools and techniques that may be incorporated to enhance their yield and thus, improve their livelihood. Using geospatial techniques in order to accurately map the potential fishing zones based on sea surface temperature (SST) and chlorophyll -a content, in conjunction with

  3. Ground-based measurement of surface temperature and thermal emissivity

    Science.gov (United States)

    Owe, M.; Van De Griend, A. A.

    1994-01-01

    Motorized cable systems for transporting infrared thermometers have been used successfully during several international field campaigns. Systems may be configured with as many as four thermal sensors up to 9 m above the surface, and traverse a 30 m transect. Ground and canopy temperatures are important for solving the surface energy balance. The spatial variability of surface temperature is often great, so that averaged point measurements result in highly inaccurate areal estimates. The cable systems are ideal for quantifying both temporal and spatial variabilities. Thermal emissivity is also necessary for deriving the absolute physical temperature, and measurements may be made with a portable measuring box.

  4. A model of the ground surface temperature for micrometeorological analysis

    Science.gov (United States)

    Leaf, Julian S.; Erell, Evyatar

    2017-07-01

    Micrometeorological models at various scales require ground surface temperature, which may not always be measured in sufficient spatial or temporal detail. There is thus a need for a model that can calculate the surface temperature using only widely available weather data, thermal properties of the ground, and surface properties. The vegetated/permeable surface energy balance (VP-SEB) model introduced here requires no a priori knowledge of soil temperature or moisture at any depth. It combines a two-layer characterization of the soil column following the heat conservation law with a sinusoidal function to estimate deep soil temperature, and a simplified procedure for calculating moisture content. A physically based solution is used for each of the energy balance components allowing VP-SEB to be highly portable. VP-SEB was tested using field data measuring bare loess desert soil in dry weather and following rain events. Modeled hourly surface temperature correlated well with the measured data (r 2 = 0.95 for a whole year), with a root-mean-square error of 2.77 K. The model was used to generate input for a pedestrian thermal comfort study using the Index of Thermal Stress (ITS). The simulation shows that the thermal stress on a pedestrian standing in the sun on a fully paved surface, which may be over 500 W on a warm summer day, may be as much as 100 W lower on a grass surface exposed to the same meteorological conditions.

  5. Mitigating ground vibration by periodic inclusions and surface structures

    DEFF Research Database (Denmark)

    Andersen, Lars Vabbersgaard; Bucinskas, Paulius; Persson, Peter

    2016-01-01

    -dimensional finite-element model. The laboratory model employs soaked mattress foam placed within a box to mimic a finite volume of soil. The dynamic properties of the soaked foam ensure wavelengths representative of ground vibration in small scale. Comparison of the results from the two models leads......Ground vibration from traffic is a source of nuisance in urbanized areas. Trenches and wave barriers can provide mitigation of vibrations, but single barriers need to have a large depth to be effective-especially in the low-frequency range relevant to traffic-induced vibration. Alternatively...... well-defined behavior can be expected for transient loads and finite structures. However, some mitigation may occur. The paper aims at quantifying the mitigation effect of nearly periodic masses placed on the ground surface using two approaches: a small-scale laboratory model and a three...

  6. Practical aspects of tritium measurement in ground and surface waters

    Energy Technology Data Exchange (ETDEWEB)

    Nitzsche, O. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Angewandte Physik; Hebert, D. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Angewandte Physik

    1997-03-01

    Tritium measurements are a powerful tool in hydrological and hydrogeological investigations for detecting mean residence times of several water reservoirs. Due to the low tritium activities in precipitation, ground and surface waters a low level measurement is necessary. Therefore often the liquid scintillation counting after an electrolytic enrichment of water is used. In this paper some practical aspects and problems of measurement are discussed and the problem of contamination in low level laboratories is shown. (orig.)

  7. Tomography of ground water flow from self-potential data

    Science.gov (United States)

    Revil, A.; Jardani, A.

    2007-12-01

    An inversion algorithm is developed to interpret self-potential (SP) data in terms of distribution of the seepage velocity of the ground water. The model is based on the proportionality existing between the electrokinetic source current density and the seepage velocity of the water phase. As the inverse problem is underdetermined, we use a Tikhonov regularization method with a smoothness constraint based on the differential Laplacian operator to solve the inverse problem. The regularization parameter is determined by the L-shape method. The recovery of the distribution of the seepage velocity vector of the ground water flow depends on the localization and number of non-polarizing electrodes and information relative to the distribution of the electrical resistivity of the ground. The inversion method is tested on two 2D synthetic cases and on two real SP data. The first field test corresponds to the infiltration of water from a ditch. The second one corresponds to large flow at the Cerro Prieto geothermal field in Baja California.

  8. Simulation of the Regional Ground-Water-Flow System and Ground-Water/Surface-Water Interaction in the Rock River Basin, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.

    2009-01-01

    A regional, two-dimensional, areal ground-water-flow model was developed to simulate the ground-water-flow system and ground-water/surface-water interaction in the Rock River Basin. The model was developed by the U.S. Geological Survey (USGS), in cooperation with the Rock River Coalition. The objectives of the regional model were to improve understanding of the ground-water-flow system and to develop a tool suitable for evaluating the effects of potential regional water-management programs. The computer code GFLOW was used because of the ease with which the model can simulate ground-water/surface-water interactions, provide a framework for simulating regional ground-water-flow systems, and be refined in a stepwise fashion to incorporate new data and simulate ground-water-flow patterns at multiple scales. The ground-water-flow model described in this report simulates the major hydrogeologic features of the modeled area, including bedrock and surficial aquifers, ground-water/surface-water interactions, and ground-water withdrawals from high-capacity wells. The steady-state model treats the ground-water-flow system as a single layer with hydraulic conductivity and base elevation zones that reflect the distribution of lithologic groups above the Precambrian bedrock and a regionally significant confining unit, the Maquoketa Formation. In the eastern part of the Basin where the shale-rich Maquoketa Formation is present, deep ground-water flow in the sandstone aquifer below the Maquoketa Formation was not simulated directly, but flow into this aquifer was incorporated into the GFLOW model from previous work in southeastern Wisconsin. Recharge was constrained primarily by stream base-flow estimates and was applied uniformly within zones guided by regional infiltration estimates for soils. The model includes average ground-water withdrawals from 1997 to 2006 for municipal wells and from 1997 to 2005 for high-capacity irrigation, industrial, and commercial wells. In addition

  9. The potential of ground gravity measurements to validate GRACE data

    Directory of Open Access Journals (Sweden)

    D. Crossley

    2003-01-01

    Full Text Available New satellite missions are returning high precision, time-varying, satellite measurements of the Earth’s gravity field. The GRACE mission is now in its calibration/- validation phase and first results of the gravity field solutions are imminent. We consider here the possibility of external validation using data from the superconducting gravimeters in the European sub-array of the Global Geodynamics Project (GGP as ‘ground truth’ for comparison with GRACE. This is a pilot study in which we use 14 months of 1-hour data from the beginning of GGP (1 July 1997 to 30 August 1998, when the Potsdam instrument was relocated to South Africa. There are 7 stations clustered in west central Europe, and one station, Metsahovi in Finland. We remove local tides, polar motion, local and global air pressure, and instrument drift and then decimate to 6-hour samples. We see large variations in the time series of 5–10µgal between even some neighboring stations, but there are also common features that correlate well over the 427-day period. The 8 stations are used to interpolate a minimum curvature (gridded surface that extends over the geographical region. This surface shows time and spatial coherency at the level of 2– 4µgal over the first half of the data and 1–2µgal over the latter half. The mean value of the surface clearly shows a rise in European gravity of about 3µgal over the first 150 days and a fairly constant value for the rest of the data. The accuracy of this mean is estimated at 1µgal, which compares favorably with GRACE predictions for wavelengths of 500 km or less. Preliminary studies of hydrology loading over Western Europe shows the difficulty of correlating the local hydrology, which can be highly variable, with large-scale gravity variations.Key words. GRACE, satellite gravity, superconducting gravimeter, GGP, ground truth

  10. Alpha Decay Half-Lives of Some Nuclei from Ground State to Ground State with Yukawa Proximity Potential

    Institute of Scientific and Technical Information of China (English)

    E.Javadimanesh; H.Hassanabadi; A.A.Rajabi; H.Rahimov; S.Zarrinkamar

    2012-01-01

    We study the half-lives of some nuclei via the alpha-decay process from ground state to ground state. To go through the problem, we have considered a potential model with Yukawa proximity potential and have thereby calculated the half-lives. The comparison with the existing data is motivating.

  11. Electric Signals on and under the Ground Surface Induced by Seismic Waves

    Directory of Open Access Journals (Sweden)

    Akihiro Takeuchi

    2012-01-01

    Full Text Available We constructed three observation sites in northeastern Japan (Honjo, Kyowa, and Sennan with condenser-type large plate electrodes (4 × 4 m2 as sensors supported 4 m above the ground and with pairs of reference electrodes buried vertically at 0.5 m and 2.5 m depth (with a ground velocity sensor at Sennan only. Electrical signals of an earthquake (M6.3 in northeastern Japan were detected simultaneously with seismic waves. Their waveforms were damped oscillations, with greatly differing signal amplitudes among sites. Good positive correlation was found between the amplitudes of signals detected by all electrodes. We propose a signal generation model: seismic acceleration vertically shook pore water in the topsoil, generating the vertical streaming potential between the upper unsaturated water zone and the lower saturated water zone. Maximum electric earth potential difference was observed when one electrode was in the saturated water zone, and the other was within the unsaturated water zone, but not when the electrodes were in the saturated water zone. The streaming potential formed a charge on the ground surface, generating a vertical atmospheric electric field. The large plate electrode detected electric signals related to electric potential differences between the electrode and the ground surface.

  12. Ground Surface Deformations Near a Fault-Bounded Groundwater Aquifer

    Science.gov (United States)

    Lipovsky, B.; Funning, G. J.; Ferretti, A.

    2011-12-01

    Geodetic data often reveal the presence of groundwater aquifers that are bounded by faults (Schmidt and Bürgmann, 2003; Galloway and Hoffmann, 2007; Bell et al., 2008). Whereas unrestricted groundwater aquifers exhibit a radially symmetric pattern of uplift with diffuse boundaries, aquifers that are bounded by faults have one or more sharp, linear boundaries. Interferometric synthetic aperture (InSAR) data, due to their high spatial density, are particularly well suited to observe fault bounded aquifers, and the Santa Clara Aquifer in the San Francisco Bay Area, California, constitutes an excellent example. The largest ground surface displacements in the Bay Area are due to the inflation of the Santa Clara aquifer, and InSAR data plainly show that the Santa Clara aquifer is partitioned by the Silver Creek fault. This study first develops a general model of the displacements at the surface of the Earth due to fluid diffusion through a buried permeable boundary such as a fault zone. This model is compared to InSAR data from the Silver Creek fault and we find that we are able to infer fault zone poromechanical properties from InSAR data that are comparable to in situ measurements. Our theoretical model is constrained by several geological and hydrological observations concerning the structure of fault zones. Analytical solutions are presented for the ground surface displacements due to a perfectly impermeable fault zone. This end-member family of models, however, does not fit the available data. We therefore make allowance for an arbitrarily layered, variably permeable, one-dimensional fault zone. Time-dependent ground surface deformations are calculated in the Laplace domain using an efficient semi-analytic method. This general model is applicable to other poroelastic regimes including geothermal and hydrocarbon systems. We are able to estimate fault zone hydraulic conductivity by comparing theoretical ground surface displacements in a permeable fault zone to

  13. Modeling analysis of ground water recharge potential on alluvial fans using limited data.

    Science.gov (United States)

    Munévar, A; Mariño, M A

    1999-01-01

    A modeling approach is developed to evaluate the potential for artificial recharge on alluvial fans in the Salinas Valley, California, using limited data of soil texture, soil hydraulic properties, and interwell stratigraphy. Promising areas for surface recharge are identified and mapped on a broad-scale using soil surveys, geologic investigations, permeability tests, and seasonal ground water response to rainfall and runoff. Two-dimensional representations of the vadose zone at selected sites are then constructed from drillers'logs and soil material types are estimated. Next, hydraulic properties are assigned to each soil material type by comparing them to laboratory-tested cores of similar soils taken from one site. Finally, water flow through the vadose zone is modeled in two dimensions at seven sites using a transient, finite-difference, variably saturated flow model. Average infiltration rates range from 0.84 to 1.54 cm/hr and recharge efficiency, the percentage of infiltrated water that reaches the water table, varies from 51% to 79%. Infiltration rates and recharge efficiency are found to be relatively insensitive to recharge basin ponding depth due to the thickness of the vadose zones modeled (31 to 84 m). The impact of artificial recharge on the Salinas Valley ground water basin is investigated by simulating the regional ground water response to surface spreading and streamflow augmentation with a recently calibrated, finite-element, ground water-surface water model for the basin. It was determined that a combined approach of surface recharge and streamflow augmentation significantly reduces the state of ground water overdraft and, to a lesser extent, reduces the rate of sea water intrusion.

  14. Stable surface solitons in truncated complex potentials.

    Science.gov (United States)

    He, Yingji; Mihalache, Dumitru; Zhu, Xing; Guo, Lina; Kartashov, Yaroslav V

    2012-07-01

    We show that surface solitons in the one-dimensional nonlinear Schrödinger equation with truncated complex periodic potential can be stabilized by linear homogeneous losses, which are necessary to balance gain in the near-surface channel arising from the imaginary part of potential. Such solitons become stable attractors when the strength of homogeneous losses acquires values from a limited interval and they exist in focusing and defocusing media. The domains of stability of the surface solitons shrink with an increase in the amplitude of the imaginary part of complex potential.

  15. Stable surface solitons in truncated complex potentials

    CERN Document Server

    He, Yingji; Zhu, Xing; Guo, Lina; Kartashov, Yaroslav V

    2012-01-01

    We show that surface solitons in the one-dimensional nonlinear Schr\\"odinger equation with truncated complex periodic potential can be stabilized by linear homogeneous losses, which are necessary to balance gain in the near-surface channel arising from the imaginary part of potential. Such solitons become stable attractors when the strength of homogeneous losses acquires values from a limited interval and they exist in focusing and defocusing media. The domains of stability of surface solitons shrink with increase of the amplitude of imaginary part of complex potential.

  16. Potential energy surfaces and reaction dynamics of polyatomic molecules

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yan-Tyng.

    1991-11-01

    A simple empirical valence bond (EVB) model approach is suggested for constructing global potential energy surfaces for reactions of polyatomic molecular systems. This approach produces smooth and continuous potential surfaces which can be directly utilized in a dynamical study. Two types of reactions are of special interest, the unimolecular dissociation and the unimolecular isomerization. For the first type, the molecular dissociation dynamics of formaldehyde on the ground electronic surface is investigated through classical trajectory calculations on EVB surfaces. The product state distributions and vector correlations obtained from this study suggest very similar behaviors seen in the experiments. The intramolecular hydrogen atom transfer in the formic acid dimer is an example of the isomerization reaction. High level ab initio quantum chemistry calculations are performed to obtain optimized equilibrium and transition state dimer geometries and also the harmonic frequencies.

  17. A shear wave ground surface vibration technique for the detection of buried pipes

    Science.gov (United States)

    Muggleton, J. M.; Papandreou, B.

    2014-07-01

    A major UK initiative, entitled 'Mapping the Underworld' aims to develop and prove the efficacy of a multi-sensor device for accurate remote buried utility service detection, location and, where possible, identification. One of the technologies to be incorporated in the device is low-frequency vibro-acoustics; the application of this technology for detecting buried infrastructure, in particular pipes, is currently being investigated. Here, a shear wave ground vibration technique for detecting buried pipes is described. For this technique, shear waves are generated at the ground surface, and the resulting ground surface vibrations measured. Time-extended signals are employed to generate the illuminating wave. Generalized cross-correlation functions between the measured ground velocities and a reference measurement adjacent to the excitation are calculated and summed using a stacking method to generate a cross-sectional image of the ground. To mitigate the effects of other potential sources of vibration in the vicinity, the excitation signal can be used as an additional reference when calculating the cross-correlation functions. Measurements have been made at two live test sites to detect a range of buried pipes. Successful detection of the pipes was achieved, with the use of the additional reference signal proving beneficial in the noisier of the two environments.

  18. Scanning Surface Potential Microscopy of Spore Adhesion on Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ida [University of Tennessee, Knoxville (UTK); Chung, Eunhyea [Georgia Institute of Technology; Kweon, Hyojin [Georgia Institute of Technology; Yiacoumi, Sotira [Georgia Institute of Technology; Tsouris, Costas [ORNL

    2012-01-01

    The adhesion of spores of Bacillus anthracis - the cause of anthrax and a likely biological threat - to solid surfaces is an important consideration in cleanup after an accidental or deliberate release. However, because of safety concerns, directly studying B. anthracis spores with advanced instrumentation is problematic. As a first step, we are examining the electrostatic potential of Bacillus thuringiensis (Bt), which is a closely related species that is often used as a simulant to study B. anthracis. Scanning surface potential microscopy (SSPM), also known as Kelvin probe force microscopy (KPFM), was used to investigate the influence of relative humidity (RH) on the surface electrostatic potential of Bt that had adhered to silica, mica, or gold substrates. AFM/SSPM side-by-side images were obtained separately in air, at various values of RH, after an aqueous droplet with spores was applied on each surface and allowed to dry before measurements. In the SSPM images, a negative potential on the surface of the spores was observed compared with that of the substrates. The surface potential decreased as the humidity increased. Spores were unable to adhere to a surface with an extremely negative potential, such as mica.

  19. Tracking Surface Cyclones with Moist Potential Vorticity

    Institute of Scientific and Technical Information of China (English)

    Zuohao CAO; Da-Lin ZHANG

    2004-01-01

    Surface cyclone tracks are investigated in the context of moist potential vorticity (MPV). A prognostic equation of surface absolute vorticity is derived which provides a basis for using negative MPV (NMPV) in the troposphere as an alternative approach to track surface cyclones. An observed case study of explosive lee cyclogenesis is performed to test the effectiveness of the MPV approach. It is shown that when a surface cyclone signal is absent due to the blocking of the Rocky Mountains, the surface cyclone can be well identified by tracing the peak NMPV.

  20. Diurnal freeze/thaw cycles of the ground surface on the Tibetan Plateau

    Institute of Scientific and Technical Information of China (English)

    YANG MeiXue; YAO TanDong; GOU XiaoHua; HIROSE Nozomu; FUJII Hide Yuki; HAO LiSheng; D.F.LEVIA

    2007-01-01

    The exchange of energy and water between the lithosphere and atmosphere mainly takes place at the ground surface. Therefore, freeze/thaw condition at the ground surface is an important factor in examining the interactions between the land surface and atmosphere. Based on the observation data obtained by CEOP/CAMP-Tibet, the diurnal freeze/thaw cycles of the ground surface near Naqu, central Tibetan Plateau was preliminarily analyzed. The results show that the surface layer was completely frozen for approximately one month. However, the time that the ground surface experienced diurnal freeze/thaw cycles was about 6 months. The high frequency of freeze/thaw cycles at the ground surface significantly influences water and energy exchanges between ground and atmosphere over half a year. The interaction processes between the ground and atmosphere under different soil conditions (such as complete thaw, complete freeze and diurnal freeze/thaw cycles) are issues worthy of further examination.

  1. Contamination of ground water, surface water, and soil, and evaluation of selected ground-water pumping alternatives in the Canal Creek area of Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Lorah, Michelle M.; Clark, Jeffrey S.

    1996-01-01

    Chemical manufacturing, munitions filling, and other military-support activities have resulted in the contamination of ground water, surface water, and soil in the Canal Creek area of Aberdeen Proving Ground, Maryland. Chlorinated volatile organic compounds, including 1,1,2,2-tetrachloroethane and trichloroethylene, are widespread ground-water contaminants in two aquifers that are composed of unconsolidated sand and gravel. Distribution and fate of chlorinated organic compounds in the ground water has been affected by the movement and dissolution of solvents in their dense immiscible phase and by microbial degradation under anaerobic conditions. Detection of volatile organic contaminants in adjacent surface water indicates that shallow contaminated ground water discharges to surface water. Semivolatile organic compounds, especially polycyclic aromatic hydrocarbons, are the most prevalent organic contaminants in soils. Various trace elements, such as arsenic, cadmium, lead, and zinc, were found in elevated concentrations in ground water, surface water, and soil. Simulations with a ground-water-flow model and particle tracker postprocessor show that, without remedial pumpage, the contaminants will eventually migrate to Canal Creek and Gunpowder River. Simulations indicate that remedial pumpage of 2.0 million gallons per day from existing wells is needed to capture all particles originating in the contaminant plumes. Simulated pumpage from offsite wells screened in a lower confined aquifer does not affect the flow of contaminated ground water in the Canal Creek area.

  2. GROUND SURFACE VISUALIZATION USING RED RELIEF IMAGE MAP FOR A VARIETY OF MAP SCALES

    Directory of Open Access Journals (Sweden)

    T. Chiba

    2016-06-01

    Full Text Available There are many methods to express topographical features of ground surface. In which, contour map has been the traditional method and along with development of digital data, surface model such as shaded relief map has been using for ground surface expression. Recently, data acquisition has been developed very much quick, demanding more advanced visualization method to express ground surface so as to effectively use the high quality data. In this study, the authors using the Red Relief Image Map (RRIM, Chiba et al., 2008 to express ground surface visualization for a variety of map scales. The authors used 30 m mesh data of SRTM to show the topographical features of western Mongolian and micro-topographical features of ground surface in tectonically active regions of Japan. The results show that, compared to traditional and other similar methods, the RRIM can express ground surface more precisely and 3-dimensionally, suggested its advanced usage for many fields of topographical visualization.

  3. Ground Surface Visualization Using Red Relief Image Map for a Variety of Map Scales

    Science.gov (United States)

    Chiba, T.; Hasi, B.

    2016-06-01

    There are many methods to express topographical features of ground surface. In which, contour map has been the traditional method and along with development of digital data, surface model such as shaded relief map has been using for ground surface expression. Recently, data acquisition has been developed very much quick, demanding more advanced visualization method to express ground surface so as to effectively use the high quality data. In this study, the authors using the Red Relief Image Map (RRIM, Chiba et al., 2008) to express ground surface visualization for a variety of map scales. The authors used 30 m mesh data of SRTM to show the topographical features of western Mongolian and micro-topographical features of ground surface in tectonically active regions of Japan. The results show that, compared to traditional and other similar methods, the RRIM can express ground surface more precisely and 3-dimensionally, suggested its advanced usage for many fields of topographical visualization.

  4. Potential Enhancement of Ground Penetrating Surveys with Dispersion Properties

    Science.gov (United States)

    Tsai, C. A.; Ghent, R. R.; Boivin, A.

    2016-12-01

    Ground penetrating radar (GPR) is a nondestructive measurement technique that utilizes the transmission or reflection of electromagnetic waves to locate targets buried under Earth or artificial materials. GPR is now widely used in mining, civil engineering archaeology and hydrology. One basic premise of surface GPR is that subsurface features will return reflections which are replicas of the transmitted signal. However, phase velocities of electromagnetic waves in real materials vary with frequency. This effect becomes more noticeable in GPR frequency range with increasing moisture content. Dispersion leads to difficulty in interpreting the received signals because the reflected signals are distorted. However, the effects of dispersion on the signals may provide an opportunity to more fully characterize materials under test than is possible using traditional reflection-mode GPR techniques. In this work we present 3D-FDTD numerical modeling results using gprMax to systematically characterize the effect of dispersion on GPR signals. In addition to numerical results, we assess the feasibility of applying our results to terrestrial geophysical scenarios by measuring the dielectric permittivities of a selection of natural materials, including samples from a massive sulphide mine. Our goal is to establish a parameter space that systematically characterize the effect of each parameter in the common dispersion models (Debye, Lorentz and Drude) on GPR signals. We begin the experiment by drying the samples completely and then adding water into the samples in 5 wt % increments. We measure the broadband relative permittivity and loss tangent using a coaxial transmission line for each state from 300 kHz to 8.5 GHz. The results provide a database for future GPR signal interpretation.

  5. Urban Surfaces and Heat Island Mitigation Potentials

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Hashem; Akbari, Hashem; Shea Rose, Leanna

    2007-06-14

    Data on materials and surface types that comprise a city, i.e. urban fabric, are needed in order to estimate the effects of light-colored surfaces (roofs and pavements) and urban vegetation (trees, grass, shrubs) on the meteorology and air quality of a city. We discuss the results of a semi-automatic statistical approach used to develop data on surface-type distribution and urban-fabric makeup using aerial color orthophotography, for four metropolitan areas of Chicago, IL, Houston, TX, Sacramento, CA, and Salt Lake City, UT. The digital high resolution (0.3 to 0.5-m) aerial photographs for each of these metropolitan areas covers representative urban areas ranging from 30 km{sup 2} to 52 km{sup 2}. Major land-use types examined included: commercial, residential, industrial, educational, and transportation. On average, for the metropolitan areas studied, vegetation covers about 29-41% of the area, roofs 19-25%, and paved surfaces 29-39%. For the most part, trees shade streets, parking lots, grass, and sidewalks. At ground level, i.e., view from below the tree canopies, vegetation covers about 20-37% of the area, roofs 20-25%, and paved surfaces 29-36%.

  6. Locally controlled globally smooth ground surface reconstruction from terrestrial point clouds

    CERN Document Server

    Rychkov, Igor

    2012-01-01

    Approaches to ground surface reconstruction from massive terrestrial point clouds are presented. Using a set of local least squares (LSQR) planes, the "holes" are filled either from the ground model of the next coarser level or by Hermite Radial Basis Functions (HRBF). Global curvature continuous as well as infinitely smooth ground surface models are obtained with Partition of Unity (PU) using either tensor product B-Splines or compactly supported exponential function. The resulting surface function has local control enabling fast evaluation.

  7. Ground state properties of a Bose-Einstein condensate confined in an anharmonic external potential

    Institute of Scientific and Technical Information of China (English)

    Wang Deng-Long; Yan Xiao-Hong; Tang Yi

    2004-01-01

    In light of the interference experiment of Bose-Einstein condensates, we present an anharmonic external potential model to study ground state properties of Bose-Einstein condensates. The ground state energy and the chemical potential have been analytically obtained, which are lower than those in harmonic trap. Additionally, it is found that the anharmonic strength of the external potential has an important effect on density and velocity distributions of the ground state for the Thomas-Fermi model.

  8. Interpreting Ground Temperature Measurements for Thermophysical Properties on Complex Surfaces of the Moon and Mars

    Science.gov (United States)

    Vasavada, A. R.; Hamilton, V. E.; Team, M.

    2013-12-01

    With the successful deployments of the Diviner radiometer on the Lunar Reconnaissance Orbiter and the REMS ground temperature sensor on the Curiosity Mars rover, records of ground temperature with high accuracy and finely sampled diurnal and seasonal cycles have become available. The detailed shapes of these temperature profiles allow inferences beyond just bulk thermophysical properties. Subtle (or sometime significant) effects of surface roughness, slope, and lateral and vertical heterogeneity may be identified in the surface brightness temperature data. For example, changes in thermal or physical properties with depth in the shallow subsurface affect the conduction and storage of thermal energy. These affect the surface energy balance and therefore surface temperatures, especially the rate of cooling at night. Making unique determinations of subsurface soil properties requires minimizing the uncertainties introduced by other effects. On Mars, atmospheric aerosol opacity and wind-driven sensible heat fluxes also affect the diurnal and annual temperature profiles. On both bodies, variations in thermal inertia, slopes, roughness, albedo, and emissivity within the radiometer footprint will cause the composite brightness temperature to differ from a kinetic temperature. Nevertheless, we have detected potential effects of complex surfaces in the temperature data from both Diviner and Curiosity. On the Moon, the results reveal a nearly ubiquitous surface structure, created mechanically by impact gardening, that controls the thermal response of the surface. On Mars, the thermal response is controlled primarily by grain size, cementation, lithification, and composition. However, the secondary effects of near-surface layering aid in the interpretation of stratigraphy and in the identification of geologic processes that have altered the surface.

  9. Potential energy surface of alanine polypeptide chains

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Yakubovich, Alexander V.; Solov'yov, Andrey V.

    2006-01-01

    The multidimensional potential energy surfaces of the peptide chains consisting of three and six alanine (Ala) residues have been studied with respect to the degrees of freedom related to the twist of these molecules relative to the peptide backbone (these degrees of freedom are responsible...

  10. Measured ground-surface movements, Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Massey, B.L.

    1981-01-01

    The Cerro Prieto geothermal area in the Mexicali Valley, 30 kilometers southeast of Mexicali, Baja California, incurred slight deformation because of the extraction of hot water and steam, and probably, active tectonism. During 1977 to 1978, the US Geological Survey established and measured two networks of horizontal control in an effort to define both types of movement. These networks consisted of: (1) a regional trilateration net brought into the mountain ranges west of the geothermal area from stations on an existing US Geological Survey crustal-strain network north of the international border; and (2) a local net tied to stations in the regional net and encompassing the present and planned geothermal production area. Electronic distance measuring instruments were used to measure the distances between stations in both networks in 1978, 1979 and 1981. Lines in the regional net averaged 25 km. in length and the standard deviation of an individual measurement is estimated to be approx. 0.3 part per million of line length. The local network was measured using different instrumentation and techniques. The average line length was about 5 km. and the standard deviation of an individual measurement approached 3 parts per million per line length. Ground-surface movements in the regional net, as measured by both the 1979 and 1981 resurveys, were small and did not exceed the noise level. The 1979 resurvey of the local net showed an apparent movement of 2 to 3 centimeters inward toward the center of the production area. This apparent movement was restricted to the general limits of the production area. The 1981 resurvey of the local net did not show increased movement attributable to fluid extraction.

  11. Influence of geology on arsenic concentrations in ground and surface water in central Lesvos, Greece.

    Science.gov (United States)

    Aloupi, Maria; Angelidis, Michael O; Gavriil, Apostolos M; Koulousaris, Michael; Varnavas, Soterios P

    2009-04-01

    The occurrence of As was studied in groundwater used for human consumption and irrigation, in stream water and sediments and in water from thermal springs in the drainage basin of Kalloni Gulf, island of Lesvos, Greece, in order to investigate the potential influence of the geothermal field of Polichnitos-Lisvori on the ground and surface water systems of the area. Total dissolved As varied in the range geology exerts a determinant influence on As geochemical behaviour. On the other hand, the geothermal activity manifested in the area of Polichnitos-Lisvori does not affect the presence of As in groundwater and streams.

  12. Shallow Alluvial Aquifer Ground Water System and Surface Water/Ground Water Interaction, Boulder Creek, Boulder, Colorado

    Science.gov (United States)

    Babcock, K. P.; Ge, S.; Crifasi, R. R.

    2006-12-01

    Water chemistry in Boulder Creek, Colorado, shows significant variation as the Creek flows through the City of Boulder [Barber et al., 2006]. This variation is partially due to ground water inputs, which are not quantitatively understood. The purpose of this study is (1) to understand ground water movement in a shallow alluvial aquifer system and (2) to assess surface water/ground water interaction. The study area, encompassing an area of 1 mi2, is located at the Sawhill and Walden Ponds area in Boulder. This area was reclaimed by the City of Boulder and Boulder County after gravel mining operations ceased in the 1970's. Consequently, ground water has filled in the numerous gravel pits allowing riparian vegetation regrowth and replanting. An integrated approach is used to examine the shallow ground water and surface water of the study area through field measurements, water table mapping, graphical data analysis, and numerical modeling. Collected field data suggest that lateral heterogeneity exists throughout the unconsolidated sediment. Alluvial hydraulic conductivities range from 1 to 24 ft/day and flow rates range from 0.01 to 2 ft/day. Preliminary data analysis suggests that ground water movement parallels surface topography and does not noticeably vary with season. Recharge via infiltrating precipitation is dependent on evapotranspiration (ET) demands and is influenced by preferential flow paths. During the growing season when ET demand exceeds precipitation rates, there is little recharge; however recharge occurs during cooler months when ET demand is insignificant. Preliminary data suggest that the Boulder Creek is gaining ground water as it traverses the study area. Stream flow influences the water table for distances up to 400 feet. The influence of stream flow is reflected in the zones relatively low total dissolved solids concentration. A modeling study is being conducted to synthesize aquifer test data, ground water levels, and stream flow data. The

  13. Identifying potential ground movement as a landslide mitigation approach using resistivity method

    Science.gov (United States)

    Izzati, F. N.; Laksmana, Z. S.; Marcelina, B.; Hutabarat, S. S.; Widodo

    2017-07-01

    Landslide is defined as a form of ground movement in which land mass suddenly fails downward on a slope as aresult of gravitational pull. One of the mitigative approaches into investigating landslide is to identify a potential slip zone usingresistivity method. In this study, the array chosen to acquire the resistivity data was Wenner array as it provides a robust resolution in mapping lateral resistivity variations. This method will generate a contour map portraying thedistribution of resistivity values of the subsurface. Beforehand, a 2-dimensional forward modeling was conducted to acquire anexpected ideal result of possible potential slip zone. Landslides itself are affiliated with a low resistivity zone that is locatedbetween two high resistivity zones. This study is conducted in a ground slump in Jalan Citra Green, Northern Bandung which is comprised of mostly unconsolidated soil. By applying a least-square inversion to the resistivity data obtained, resistivity values of 10-200 Ωm is attained. Based on the inversion result, a low resistivity zone of 10-20 Ωm is identified spanning from the surface to approximately 10 meters deep. In conclusion, furtherinvestigations are needed to determine whether the low resistivity zone is associated with potential slip zone as our datais limited to a single line

  14. Influences of Grounding Site Soil Parameters on Earth Surface Potential of the High-voltage Interconnected Power Grid%高压互联电网极址土层参数对直流地表电位影响的研究

    Institute of Scientific and Technical Information of China (English)

    吴超; 吴广宁; 范建斌; 任志超; 张一坤

    2011-01-01

    HVDC接地极极址选择、布置形式和地表电位的分布在很大程度上取决于土壤结构模型,对分析HVDC输电系统单极运行时交流网络受到的影响也有重要作用.笔者利用CDEGS软件对HVDC系统及交流输电网络进行建模仿真,采用不同的土壤模型,分析研究了直流输电系统以单极大地回线方式运行时,各层土壤参数对地表电位分布的影响.仿真结果表明:直流地表电位因距离接地极的远近而不同,距离接地极越远,直流地表电位绝对值越小,近似呈指数函数形式衰减;直流地表电位数值与土壤厚度近似成反比,而与表层土壤电阻率近似成正比:土壤模型及参数的选取极大地影响了地表电位仿真计算的准确性及真实性,需综合考虑计算结果的精度要求和计算过程难易程度.%The HVDC grounding site selection, ground electrode design, and earth surface potential (ESP)distribution mainly depend on soil model, which is of great importance to analyze the influence of HVDC mono-polar operation with ground return on AC power grid. In this paper, the characteristics of the ESP under DC mono-polar operation mode were summarized with the software CEDGS according to the analysis of different soil models and variable soil parameters. The simulation results illustrate that the farther it is from the grounding site, the smaller the absolute value of ESP is with exponential attenuation. ESP shows approximately inverse proportion to soil thickness but direct proportion to resistivity of surface soil.Selections of soil model and its parameters exert significant influence on accuracy of ESP simulation,therefore the balance between accuracy and difficulty of calculation ought to be considered.

  15. Computed potential energy surfaces for chemical reactions

    Science.gov (United States)

    Walch, Stephen P.

    1994-01-01

    Quantum mechanical methods have been used to compute potential energy surfaces for chemical reactions. The reactions studied were among those believed to be important to the NASP and HSR programs and included the recombination of two H atoms with several different third bodies; the reactions in the thermal Zeldovich mechanism; the reactions of H atom with O2, N2, and NO; reactions involved in the thermal De-NO(x) process; and the reaction of CH(squared Pi) with N2 (leading to 'prompt NO'). These potential energy surfaces have been used to compute reaction rate constants and rates of unimolecular decomposition. An additional application was the calculation of transport properties of gases using a semiclassical approximation (and in the case of interactions involving hydrogen inclusion of quantum mechanical effects).

  16. Surface fatigue life of CBN and vitreous ground carburized and hardened AISI 9310 spur gears

    Science.gov (United States)

    Townsend, Dennis P.; Patel, P. R.

    1988-01-01

    Spur gear surface endurance tests were conducted to investigate CBN ground AISI 9310 spur gears for use in aircraft applications, to determine their endurance characteristics and to compare the results with the endurance of standard vitreous ground AISI 9310 spur gears. Tests were conducted with VIM-VAR AISI 9310 carburized and hardened gears that were finish ground with either CBN or vitreous grinding methods. Test conditions were an inlet oil temeprature of 320 K (116 F), an outlet oil temperature of 350 K (170 F), a maximum Hertz stress of 1.71 GPa (248 ksi), and a speed of 10,000 rpm. The CBN ground gears exhibited a surface fatigue life that was slightly better than the vitreous ground gears. The subsurface residual stress of the CBN ground gears was approximately the same as that for the standard vitreous ground gears for the CBN grinding method used.

  17. Ground State of a Two-Electron Quantum Dot with a Gaussian Confining Potential

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-Fang

    2006-01-01

    We investigate the ground-state properties of a two-dimensional two-electron quantum dot with a Gaussian confining potential under the influence of perpendicular homogeneous magnetic field. Calculations are carried out by using the method of numerical diagonalization of Hamiltonian matrix within the effective-mass approximation. A ground-state behaviour (singlet→triplet state transitions) as a function of the strength of a magnetic field has been found. It is found that the dot radius R of the Gaussian potential is important for the ground-state transition and the feature of ground-state for the Gaussian potential quantum dot (QD), and the parabolic potential QDs are similar when R is larger. The larger the quantum dot radius, the smaller the magnetic field for the singlet-triplet transition of the ground-state of two interacting electrons in the Gaussian quantum dot.

  18. Surface and borehole ground-penetrating-radar developments

    NARCIS (Netherlands)

    Slob, E.C.; Sato, M.; Olhoeft, G.

    2010-01-01

    During the past 80 years, ground-penetrating radar (GPR) has evolved from a skeptically received glacier sounder to a full multicomponent 3D volume-imaging and characterization device. The tool can be calibrated to allow for quantitative estimates of physical properties such as water content. Becau

  19. Mitigating ground vibration by periodic inclusions and surface structures

    DEFF Research Database (Denmark)

    Andersen, Lars Vabbersgaard; Bucinskas, Paulius; Persson, Peter

    2016-01-01

    Ground vibration from traffic is a source of nuisance in urbanized areas. Trenches and wave barriers can provide mitigation of vibrations, but single barriers need to have a large depth to be effective-especially in the low-frequency range relevant to traffic-induced vibration. Alternatively, per...

  20. Theoretical studies of potential energy surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Harding, L.B. [Argonne National Laboratory, IL (United States)

    1993-12-01

    The goal of this program is to calculate accurate potential energy surfaces (PES) for both reactive and nonreactive systems. To do this the electronic Schrodinger equation must be solved. Our approach to this problem starts with multiconfiguration self-consistent field (MCSCF) reference wavefunctions. These reference wavefunctions are designed to be sufficiently flexible to accurately describe changes in electronic structure over a broad range of geometries. Electron correlation effects are included via multireference, singles and doubles configuration interaction (MRSDCI) calculations. With this approach, the authors are able to provide useful predictions of the energetics for a broad range of systems.

  1. Sparse representation for a potential energy surface

    Science.gov (United States)

    Seko, Atsuto; Takahashi, Akira; Tanaka, Isao

    2014-07-01

    We propose a simple scheme to estimate the potential energy surface (PES) for which the accuracy can be easily controlled and improved. It is based on model selection within the framework of linear regression using the least absolute shrinkage and selection operator (LASSO) technique. Basis functions are selected from a systematic large set of candidate functions. The sparsity of the PES significantly reduces the computational cost of evaluating the energy and force in molecular dynamics simulations without losing accuracy. The usefulness of the scheme for describing the elemental metals Na and Mg is clearly demonstrated.

  2. Near-ground cooling efficacies of trees and high-albedo surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Levinson, R M [Univ. of California, Berkeley, CA (United States). Dept. of Mechanical Engineering

    1997-05-01

    Daytime summer urban heat islands arise when the prevalence of dark-colored surfaces and lack of vegetation make a city warmer than neighboring countryside. Two frequently-proposed summer heat island mitigation measures are to plant trees and to increase the albedo (solar reflectivity) of ground surfaces. This dissertation examines the effects of these measures on the surface temperature of an object near the ground, and on solar heating of air near the ground. Near-ground objects include people, vehicles, and buildings. The variation of the surface temperature of a near-ground object with ground albedo indicates that a rise in ground albedo will cool a near-ground object only if the object`s albedo exceeds a critical value. This critical value of object albedo depends on wind speed, object geometry, and the height of the atmospheric thermal boundary layer. It ranges from 0.15 to 0.37 for a person. If an object has typical albedo of 0.3, increasing the ground albedo by.

  3. Ground-state charge transfer as a mechanism for surface-enhanced Raman scattering

    Science.gov (United States)

    Lippitsch, Max E.

    1984-03-01

    A model is presented for the contribution of ground-state charge transfer between a metal and adsorbate to surface-enhanced Raman scattering (SERS). It is shown that this contribution can be understood using the vibronic theory for calculating Raman intensities. The enhancement is due to vibronic coupling of the molecular ground state to the metal states, the coupling mechanism being a modulation of the ground-state charge-transfer energy by the molecular vibrations. An analysis of the coupling operator gives the selection rules for this process, which turn out to be dependent on the overall symmetry of the adsorbate-metal system, even if the charge transfer is small enough for the symmetry of the adsorbate to remain the same as that of the free molecule. It is shown that the model can yield predictions on the properties of SERS, e.g., specificity to adsorption geometry, appearance of forbidden bands, dependence on the applied potential, and dependence on the excitation wavelength. The predictions are in good agreement with experimental results. It is also deduced from this model that in many cases atomic-scale roughness is a prerequisite for the observation of SERS. A result on the magnitude of the enhancement can only be given in a crude approximation. Although in most cases an additional electromagnetic enhancement seems to be necessary to give an observable signal, this charge-transfer mechanism should be important in many SERS systems.

  4. Topographical Anisotropy and Wetting of Ground Stainless Steel Surfaces

    Directory of Open Access Journals (Sweden)

    Cornelia Bellmann

    2012-12-01

    Full Text Available Microscopic and physico-chemical methods were used for a comprehensive surface characterization of different mechanically modified stainless steel surfaces. The surfaces were analyzed using high-resolution confocal microscopy, resulting in detailed information about the topographic properties. In addition, static water contact angle measurements were carried out to characterize the surface heterogeneity of the samples. The effect of morphological anisotropy on water contact angle anisotropy was investigated. The correlation between topography and wetting was studied by means of a model of wetting proposed in the present work, that allows quantifying the air volume of the interface water drop-stainless steel surface.

  5. Concentration distributions of thoron and radon near the ground surface

    Energy Technology Data Exchange (ETDEWEB)

    Katase, Akira [Tohwa Univ., Fukuoka (Japan). Faculty of Engineering

    1996-12-01

    One dimensional diffusion model with a constant diffusion coefficient is applied to the thoron concentration distributions in air above the ground. The experimental distributions are well described by the exponential function obtained from the model. Diffusion coefficients and thoron exhalation rates are estimated from the measured distributions, which are the average values for three months. The present values of thoron exhalation are however several times as small as those measured by other researchers. (author)

  6. Revised Iterative Solution of Ground State of Double-Well Potential

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wei-Qin

    2005-01-01

    The revised new iterative method for solving the ground state of Schrodinger equation is deduced. Based on Green functions defined by quadratures along a single trajectory this iterative method is applied to solve the ground state of the double-well potential. The result is compared to the one based on the original iterative method. The limitation of the asymptotic expansion is also discussed.

  7. Many-body Expanded Analytical Potential Energy Function for Ground State PuOH Molecule

    Institute of Scientific and Technical Information of China (English)

    LI Yue-Xun; GAO Tao; ZHU Zheng-He

    2006-01-01

    Using the density functional method B3LYP with relativistic effective core potential (RECP) for Pu atom, the low-lying excited states (4∑+, 6∑+, 8∑+) for three structures of PuOH molecule were optimized. The results show that the ground state is X6∑+of the linear Pu-O-H (C∞v), its corresponding equilibrium geometry and dissociation energy are RPu-O=0.20595 nm, RO-H=0.09581 nm and -8.68 eV, respectively. At the same time, two other metastable structures [PuOH (Cs) and H-Pu-O (C∞v)] were found. The analytical potential energy function has also been derived for whole range using the many-body expansion method. This potential energy function represents the considerable topographical features of PuOH molecule in detail, which is adequately accurate in the whole potential surface and can be used for the molecular reaction dynamics research.

  8. Ground effects of space weather investigated by the surface impedance

    Science.gov (United States)

    Pirjola, R.; Boteler, D.; Trichtchenko, L.

    2009-02-01

    The objective of this paper is to provide a discussion of the surface impedance applicable in connection with studies of geomagnetically induced currents (GIC) in technological systems. This viewpoint means that the surface impedance is regarded as a tool to determine the horizontal (geo)electric field at the Earth's surface, which is the key quantity for GIC. Thus the approach is different from the traditional magnetotelluric viewpoint. The definition of the surface impedance usually involves wavenumber-frequency-domain fields, so inverse Fourier transforming the expression of the electric field in terms of the surface impedance and the geomagnetic field results in convolution integrals in the time and space domains. The frequency-dependent surface impedance has a high-pass filter character whereas the corresponding transfer function between the electric field and the time derivative of the magnetic field is of a low-pass filter type. The relative change of the latter transfer function with frequency is usually smaller than that of the surface impedance, which indicates that the geoelectric field is closer to the time derivative than to the magnetic field itself. An investigation of the surface impedance defined by the space-domain electric and magnetic components indicates that the largest electric fields are not always achieved by the plane wave assumption, which is sometimes regarded as an extreme case for GIC. It is also concluded in this paper that it is often possible to apply the plane wave relation locally between the surface electric and magnetic fields. The absolute value of the surface impedance decreases with an increasing wavenumber although the maximum may also be at a non-zero value of the wavenumber. The imaginary part of the surface impedance usually much exceeds the real part.

  9. Analysis on effect of surface fault to site ground motion using finite element method

    Institute of Scientific and Technical Information of China (English)

    曹炳政; 罗奇峰

    2003-01-01

    Dynamic contact theory is applied to simulate the sliding of surface fault. Finite element method is used to analyze the effect of surface fault to site ground motions. Calculated results indicate that amplification effect is obvious in the area near surface fault, especially on the site that is in the downside fault. The results show that the effect of surface fault should be considered when important structure is constructed in the site with surface fault.

  10. Seasonal Influences on Ground-Surface Water Interactions in an Arsenic-Affected Aquifer in Cambodia

    Science.gov (United States)

    Richards, L. A.; Magnone, D.; Van Dongen, B.; Bryant, C.; Boyce, A.; Ballentine, C. J.; Polya, D. A.

    2015-12-01

    Millions of people in South and Southeast Asia consume drinking water daily which contains dangerous levels of arsenic exceeding health-based recommendations [1]. A key control on arsenic mobilization in aquifers in these areas has been controversially identified as the interaction of 'labile' organic matter contained in surface waters with groundwaters and sediments at depth [2-4], which may trigger the release of arsenic from the solid- to aqueous-phase via reductive dissolution of iron-(hyr)oxide minerals [5]. In a field site in Kandal Province, Cambodia, which is an arsenic-affected area typical to others in the region, there are strong seasonal patterns in groundwater flow direction, which are closely related to monsoonal rains [6] and may contribute to arsenic release in this aquifer. The aim of this study is to explore the implications of the high susceptibility of this aquifer system to seasonal changes on potential ground-surface water interactions. The main objectives are to (i) identify key zones where there are likely ground-surface water interactions, (ii) assess the seasonal impact of such interactions and (iii) quantify the influence of interactions using geochemical parameters (such as As, Fe, NO3, NH4, 14C, 3T/3He, δ18O, δ2H). Identifying the zones, magnitude and seasonal influence of ground-surface water interactions elucidates new information regarding potential locations/pathways of arsenic mobilization and/or transport in affected aquifers and may be important for water management strategies in affected areas. This research is supported by NERC (NE/J023833/1) to DP, BvD and CJB and a NERC PhD studentship (NE/L501591/1) to DM. References: [1] World Health Organization, 2008. [2] Charlet & Polya (2006), Elements, 2, 91-96. [3] Harvey et al. (2002), Science, 298, 1602-1606. [4] Lawson et al. (2013), Env. Sci. Technol. 47, 7085 - 7094. [5] Islam et al. (2004), Nature, 430, 68-71. [6] Benner et al. (2008) Appl. Geochem. 23(11), 3072 - 3087.

  11. Interfaces Supporting Surface Gap Soliton Ground States in the 1D Nonlinear Schroedinger Equation

    CERN Document Server

    Dohnal, Tomas; Plum, Michael; Reichel, Wolfgang

    2012-01-01

    We consider the problem of verifying the existence of $H^1$ ground states of the 1D nonlinear Schr\\"odinger equation for an interface of two periodic structures: $$-u" +V(x)u -\\lambda u = \\Gamma(x) |u|^{p-1}u \\ {on} \\R$$ with $V(x) = V_1(x), \\Gamma(x)=\\Gamma_1(x)$ for $x\\geq 0$ and $V(x) = V_2(x), \\Gamma(x)=\\Gamma_2(x)$ for $x1$. The article [T. Dohnal, M. Plum and W. Reichel, "Surface Gap Soliton Ground States for the Nonlinear Schr\\"odinger Equation," \\textit{Comm. Math. Phys.} \\textbf{308}, 511-542 (2011)] provides in the 1D case an existence criterion in the form of an integral inequality involving the linear potentials $V_{1},V_2$ and the Bloch waves of the operators $-\\tfrac{d^2}{dx^2}+V_{1,2}-\\lambda$. We choose here the classes of piecewise constant and piecewise linear potentials $V_{1,2}$ and check this criterion for a set of parameter values. In the piecewise constant case the Bloch waves are calculated explicitly and in the piecewise linear case verified enclosures of the Bloch waves are computed ...

  12. National Enforcement Initiative: Preventing Animal Waste from Contaminating Surface and Ground Water

    Science.gov (United States)

    This page describes EPA's goal in preventing animal waste from contaminating surface and ground Water. It is an EPA National Enforcement Initiative. Both enforcement cases, and a map of enforcement actions are provided.

  13. Assessment of volatile organic compounds in surface water at West Branch Canal Creek, Aberdeen Proving Ground, Maryland, 1999

    Science.gov (United States)

    Olsen, Lisa D.; Spencer, Tracey A.

    2000-01-01

    The U.S. Geological Survey (USGS) collected 13 surface-water samples and 3 replicates from 5 sites in the West Branch Canal Creek area at Aberdeen Proving Ground from February through August 1999, as a part of an investigation of ground-water contamination and natural attenuation processes. The samples were analyzed for volatile organic compounds, including trichloroethylene, 1,1,2,2-tetrachloroethane, carbon tetrachloride, and chloroform, which are the four major contaminants that were detected in ground water in the Canal Creek area in earlier USGS studies. Field blanks were collected during the sampling period to assess sample bias. Field replicates were used to assess sample variability, which was expressed as relative percent difference. The mean variability of the surface-water replicate analyses was larger (35.4 percent) than the mean variability of ground-water replicate analyses (14.6 percent) determined for West Branch Canal Creek from 1995 through 1996. The higher variability in surface-water analyses is probably due to heterogeneities in the composition of the surface water rather than differences in sampling or analytical procedures. The most frequently detected volatile organic compound was 1,1,2,2- tetrachloroethane, which was detected in every sample and in two of the replicates. The surface-water contamination is likely the result of cross-media transfer of contaminants from the ground water and sediments along the West Branch Canal Creek. The full extent of surface-water contamination in West Branch Canal Creek and the locations of probable contaminant sources cannot be determined from this limited set of data. Tidal mixing, creek flow patterns, and potential effects of a drought that occurred during the sampling period also complicate the evaluation of surface-water contamination.

  14. The Simulation of Grinding Wheels and Ground Surface Roughness Based on Virtual Reality Technology

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The paper describes the feasibility and method of the application of virtual reality technology to grinding process, and introduces the modeling method of object entity in the environment of virtual reality. The simulation process of grinding wheels and ground surface roughness is discussed, and the computation program system of numerical simulation is compiled with Visual C++ programming language. At the same time, the three-dimensional simulation models of grinding wheels and ground surface roughness are ...

  15. Uncertainties and shortcomings of ground surface temperature histories derived from inversion of temperature logs

    OpenAIRE

    Hartmann, Andreas; Rath, Volker

    2008-01-01

    Analysing borehole temperature data in terms of ground surface history can add useful information to reconstructions of past climates. Therefore, a rigorous assessment of uncertainties and error sources is a necessary prerequisite for the meaningful interpretation of such ground surface temperature histories. This study analyses the most prominent sources of uncertainty. The diffusive nature of the process makes the inversion relatively robust against incomplete knowledge of the thermal diffu...

  16. Frozen: The Potential and Pitfalls of Ground-Penetrating Radar for Archaeology in the Alaskan Arctic

    Directory of Open Access Journals (Sweden)

    Thomas M. Urban

    2016-12-01

    Full Text Available Ground-penetrating radar (GPR offers many advantages for assessing archaeological potential in frozen and partially frozen contexts in high latitude and alpine regions. These settings pose several challenges for GPR, including extreme velocity changes at the interface of frozen and active layers, cryogenic patterns resulting in anomalies that can easily be mistaken for cultural features, and the difficulty in accessing sites and deploying equipment in remote settings. In this study we discuss some of these challenges while highlighting the potential for this method by describing recent successful investigations with GPR in the region. We draw on cases from Bering Land Bridge National Preserve, Cape Krusenstern National Monument, Kobuk Valley National Park, and Gates of the Arctic National Park and Preserve. The sites required small aircraft accessibility with light equipment loads and minimal personnel. The substrates we investigate include coastal saturated active layer over permafrost, interior well-drained active layer over permafrost, a frozen thermo-karst lake, and an alpine ice patch. These examples demonstrate that GPR is effective at mapping semi-subterranean house remains in several contexts, including houses with no surface manifestation. GPR is also shown to be effective at mapping anomalies from the skeletal remains of a late Pleistocene mammoth frozen in ice. The potential for using GPR in ice and snow patch archaeology, an area of increasing interest with global environmental change exposing new material each year, is also demonstrated.

  17. Ground-water and surface-water quality data for the West Branch Canal Creek area, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Spencer, Tracey A.; Phelan, Daniel J.; Olsen, Lisa D.; Lorah, Michelle M.

    2001-01-01

    This report presents ground-water and surface-water quality data from samples collected by the U.S. Geological Survey from November 1999 through May 2001 at West Branch Canal Creek, Aberdeen Proving Ground, Maryland. The report also provides a description of the sampling and analytical methods that were used to collect and analyze the samples, and includes an evaluation of the quality-assurance data. The ground-water sampling network included two 4-inch wells, two 2-inch wells, sixteen 1-inch piezometers, one hundred thirteen 0.75-inch piezometers, two 0.25-inch flexible-tubing piezo-meters, twenty-seven 0.25-inch piezometers, and forty-two multi-level monitoring system depths at six sites. Ground-water profiler samples were collected from nine sites at 34 depths. In addition, passive-diffusion-bag samplers were deployed at four sites, and porous-membrane sampling devices were installed in the upper sediment at five sites. Surface-water samples were collected from 20 sites. Samples were collected from wells and 0.75-inch piezometers for measurement of field parameters and reduction-oxidation constituents, and analysis of inorganic and organic constituents, during three sampling events in March?April and June?August 2000, and May 2001. Surface-water samples were collected from November 1999 through September 2000 during five sampling events for analysis of organic constituents. Ground-water profiler samples were collected in April?May 2000, and analyzed for field measure-ments, reduction-oxidation constituents, and inorganic constituents and organic constituents. Passive-diffusion-bag samplers were installed in September 2000, and samples were analyzed for organic constituents. Multi-level monitoring system samples were collected and analyzed for field measurements and reduction-oxidation con-stituents, inorganic constituents, and organic con-stituents in March?April and June?August 2000. Field measurements and organic constituents were collected from 0.25-inch

  18. Kinetic and dynamic studies of the Cl(2Pu) + H2O(X̃1A1) → HCl(X̃1Σ+) + OH(X̃2Π) reaction on an ab initio based full-dimensional global potential energy surface of the ground electronic state of ClH2O.

    Science.gov (United States)

    Li, Jun; Dawes, Richard; Guo, Hua

    2013-08-21

    Extensive high-level ab initio calculations were performed on the ground electronic state of ClH2O. The barrier region for the title reaction was found to have significant multi-reference character, thus favoring the multi-reference configuration interaction (MRCI) method over single-reference methods such as coupled-cluster. A full-dimensional global potential energy surface was developed by fitting about 25 000 MRCI points using the permutation invariant polynomial method. The reaction path features a "late" barrier flanked by deep pre- and post-barrier wells. Calculated rate constants for the forward reaction are in reasonable agreement with experiment, suggesting a good representation of the forward barrier. The dynamics of the forward reaction was also investigated using a quasi-classical trajectory method at energies just above the barrier. While the OH bond is found to be a spectator, the HCl product has significant rotational excitation. The reaction proceeds via both direct rebound and stripping mechanisms, leading to backward and sideways scattering.

  19. Energy conservation potential of surface modification technologies

    Energy Technology Data Exchange (ETDEWEB)

    Le, H.K.; Horne, D.M.; Silberglitt, R.S.

    1985-09-01

    This report assesses the energy conservation impact of surface modification technologies on the metalworking industries. The energy conservation impact of surface modification technologies on the metalworking industries is assessed by estimating their friction and wear tribological sinks and the subsequent reduction in these sinks when surface modified tools are used. Ion implantation, coatings, and laser and electron beam surface modifications are considered.

  20. Adiabatic density surface, neutral density surface, potential density surface, and mixing path

    Institute of Scientific and Technical Information of China (English)

    HUANG Rui-xin

    2014-01-01

    In this paper, adiabatic density surface, neutral density surface and potential density surface are compared. The adiabatic density surface is defined as the surface on which a water parcellcan move adiabatically, without changing its potential temperature and salinity. For a water parcelltaken at a given station and pressure level, the corresponding adiabatic density surface can be determined through simple calculations. This family of surface is neutrally buoyant in the world ocean, and different from other surfaces that are not truly neutrally buoyant. In order to explore mixing path in the ocean, a mixing ratio m is introduced, which is defined as the portion of potential temperature and salinity of a water parcellthat has exchanged with the environment during a segment of migration in the ocean. Two extreme situations of mixing path in the ocean are m=0 (no mixing), which is represented by the adiabatic density curve, and m=1, where the original information is completely lost through mixing. The latter is represented by the neutral density curve. The reality lies in between, namely, 0potentially infinite mixing paths, some of which may be identified by using different tracers (or their combinations) and different mixing criteria. Searching for mixing paths in the real ocean presents a great challenge for further research.

  1. Ground and surface water for drinking: a laboratory study on genotoxicity using plant tests

    Directory of Open Access Journals (Sweden)

    Donatella Feretti

    2012-02-01

    Full Text Available Surface waters are increasingly utilized for drinking water because groundwater sources are often polluted. Several monitoring studies have detected the presence of mutagenicity in drinking water, especially from surface sources due to the reaction of natural organic matter with disinfectant. The study aimed to investigate the genotoxic potential of the products of reaction between humic substances, which are naturally present in surface water, and three disinfectants: chlorine dioxide, sodium hypochlorite and peracetic acid. Commercial humic acids dissolved in distilled water at different total organic carbon (TOC concentrations were studied in order to simulate natural conditions of both ground water (TOC=2.5 mg/L and surface water (TOC=7.5 mg/L. These solutions were treated with the biocides at a 1:1 molar ratio of C:disinfectant and tested for genotoxicity using the anaphase chromosomal aberration and micronucleus tests in Allium cepa, and the Vicia faba and Tradescantia micronucleus tests. The tests were carried out after different times and with different modes of exposure, and at 1:1 and 1:10 dilutions of disinfected and undisinfected humic acid solutions. A genotoxic effect was found for sodium hypochlorite in all plant tests, at both TOCs considered, while chlorine dioxide gave positive results only with the A.cepa tests. Some positive effects were also detected for PAA (A.cepa and Tradescantia. No relevant differences were found in samples with different TOC values. The significant increase in all genotoxicity end-points induced by all tested disinfectants indicates that a genotoxic potential is exerted even in the presence of organic substances at similar concentrations to those frequently present in drinking water.

  2. Ground and surface water for drinking: a laboratory study on genotoxicity using plant tests.

    Science.gov (United States)

    Feretti, Donatella; Ceretti, Elisabetta; Gustavino, Bianca; Zerbini, Llaria; Zani, Claudia; Monarca, Silvano; Rizzoni, Marco

    2012-02-17

    Surface waters are increasingly utilized for drinking water because groundwater sources are often polluted. Several monitoring studies have detected the presence of mutagenicity in drinking water, especially from surface sources due to the reaction of natural organic matter with disinfectant. The study aimed to investigate the genotoxic potential of the products of reaction between humic substances, which are naturally present in surface water, and three disinfectants: chlorine dioxide, sodium hypochlorite and peracetic acid. Commercial humic acids dissolved in distilled water at different total organic carbon (TOC) concentrations were studied in order to simulate natural conditions of both ground water (TOC=2.5 mg/L) and surface water (TOC=7.5 mg/L). These solutions were treated with the biocides at a 1:1 molar ratio of C:disinfectant and tested for genotoxicity using the anaphase chromosomal aberration and micronucleus tests in Allium cepa, and the Vicia faba and Tradescantia micronucleus tests. The tests were carried out after different times and with different modes of exposure, and at 1:1 and 1:10 dilutions of disinfected and undisinfected humic acid solutions. A genotoxic effect was found for sodium hypochlorite in all plant tests, at both TOCs considered, while chlorine dioxide gave positive results only with the A.cepa tests. Some positive effects were also detected for PAA (A.cepa and Tradescantia). No relevant differences were found in samples with different TOC values. The significant increase in all genotoxicity end-points induced by all tested disinfectants indicates that a genotoxic potential is exerted even in the presence of organic substances at similar concentrations to those frequently present in drinking water.

  3. A Simple Volcano Potential with an Analytic, Zero-Energy, Ground State

    CERN Document Server

    Nieto, Michael Martin

    2000-01-01

    We describe a simple volcano potential, which is supersymmetric and has an analytic, zero-energy, ground state. (The KK modes are also analytic.) It is an interior harmonic oscillator potential properly matched to an exterior angular momentum-like tail. Special cases are given to elucidate the physics, which may be intuitively useful in studies of higher-dimensional gravity.

  4. Study on the Surface Free Energy of Ground CaO by IGC

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    CaO formed by decomposing CaCO3 at 1450℃ was ground in a vibrational mill,then the long-time ground sample was reheated at different temperatures.Inverse Gas Chromatography (IGC) was used to measure the variation of the sample′s surface free energy under grinding and reheating.It is concluded that the total surface free energy and the London dispersive component of the surface free energy increases with grinding,while the polar component first increases with grinding,and then decreases,and finally disappears.When the long-time ground sample was reheated,its total surface free energy decreases,among which the London component decreases,but the polar component appears again.

  5. Ground water/surface water responses to global climate simulations, Santa Clara-Calleguas Basin, Ventura, California

    Science.gov (United States)

    Hanson, R.T.; Dettinger, M.D.

    2005-01-01

    Climate variations can play an important, if not always crucial, role in successful conjunctive management of ground water and surface water resources. This will require accurate accounting of the links between variations in climate, recharge, and withdrawal from the resource systems, accurate projection or predictions of the climate variations, and accurate simulation of the responses of the resource systems. To assess linkages and predictability of climate influences on conjunctive management, global climate model (GCM) simulated precipitation rates were used to estimate inflows and outflows from a regional ground water model (RGWM) of the coastal aquifers of the Santa ClaraCalleguas Basin at Ventura, California, for 1950 to 1993. Interannual to interdecadal time scales of the El Nin??o Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) climate variations are imparted to simulated precipitation variations in the Southern California area and are realistically imparted to the simulated ground water level variations through the climate-driven recharge (and discharge) variations. For example, the simulated average ground water level response at a key observation well in the basin to ENSO variations of tropical Pacific sea surface temperatures is 1.2 m/??C, compared to 0.9 m/??C in observations. This close agreement shows that the GCM-RGWM combination can translate global scale climate variations into realistic local ground water responses. Probability distributions of simulated ground water level excursions above a local water level threshold for potential seawater intrusion compare well to the corresponding distributions from observations and historical RGWM simulations, demonstrating the combination's potential usefulness for water management and planning. Thus the GCM-RGWM combination could be used for planning purposes and - when the GCM forecast skills are adequate - for near term predictions.

  6. Salmonella pollution in ground and surface waters. (Latest citations from Pollution abstracts). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    1993-04-01

    The bibliography contains citations concerning the contamination of ground waters and surface waters by Salmonella bacteria. Articles discuss the occurence, survival, origin, and control of these bacteria in water sources including rivers, reservoirs, swimming pools, wastewater, aquifers, and ground water. Citations also address the use of Salmonella populations as biological indicators of pollution in aquatic systems. (Contains a minimum of 102 citations and includes a subject term index and title list.)

  7. Probing the limitations of isotropic pair potentials to produce ground-state structural extremes via inverse statistical mechanics.

    Science.gov (United States)

    Zhang, G; Stillinger, F H; Torquato, S

    2013-10-01

    Inverse statistical-mechanical methods have recently been employed to design optimized short-range radial (isotropic) pair potentials that robustly produce novel targeted classical ground-state many-particle configurations. The target structures considered in those studies were low-coordinated crystals with a high degree of symmetry. In this paper, we further test the fundamental limitations of radial pair potentials by targeting crystal structures with appreciably less symmetry, including those in which the particles have different local structural environments. These challenging target configurations demanded that we modify previous inverse optimization techniques. In particular, we first find local minima of a candidate enthalpy surface and determine the enthalpy difference ΔH between such inherent structures and the target structure. Then we determine the lowest positive eigenvalue λ(0) of the Hessian matrix of the enthalpy surface at the target configuration. Finally, we maximize λ(0)ΔH so that the target structure is both locally stable and globally stable with respect to the inherent structures. Using this modified optimization technique, we have designed short-range radial pair potentials that stabilize the two-dimensional kagome crystal, the rectangular kagome crystal, and rectangular lattices, as well as the three-dimensional structure of the CaF(2) crystal inhabited by a single-particle species. We verify our results by cooling liquid configurations to absolute zero temperature via simulated annealing and ensuring that such states have stable phonon spectra. Except for the rectangular kagome structure, all of the target structures can be stabilized with monotonic repulsive potentials. Our work demonstrates that single-component systems with short-range radial pair potentials can counterintuitively self-assemble into crystal ground states with low symmetry and different local structural environments. Finally, we present general principles that offer

  8. Estrogen and androgen receptor activities of hydraulic fracturing chemicals and surface and ground water in a drilling-dense region

    Science.gov (United States)

    Kassotis, Christopher D.; Tillitt, Donald E.; Davis, J. Wade; Hormann, Anette M.; Nagel, Susan C.

    2014-01-01

    The rapid rise in natural gas extraction using hydraulic fracturing increases the potential for contamination of surface and ground water from chemicals used throughout the process. Hundreds of products containing more than 750 chemicals and components are potentially used throughout the extraction process, including more than 100 known or suspected endocrine-disrupting chemicals. We hypothesized thataselected subset of chemicalsusedin natural gas drilling operationsandalso surface and ground water samples collected in a drilling-dense region of Garfield County, Colorado, would exhibit estrogen and androgen receptor activities. Water samples were collected, solid-phase extracted, and measured for estrogen and androgen receptor activities using reporter gene assays in human cell lines. Of the 39 unique water samples, 89%, 41%, 12%, and 46% exhibited estrogenic, antiestrogenic, androgenic, and antiandrogenic activities, respectively. Testing of a subset of natural gas drilling chemicals revealed novel antiestrogenic, novel antiandrogenic, and limited estrogenic activities. The Colorado River, the drainage basin for this region, exhibited moderate levels of estrogenic, antiestrogenic, and antiandrogenic activities, suggesting that higher localized activity at sites with known natural gas–related spills surrounding the river might be contributing to the multiple receptor activities observed in this water source. The majority of water samples collected from sites in a drilling-dense region of Colorado exhibited more estrogenic, antiestrogenic, or antiandrogenic activities than reference sites with limited nearby drilling operations. Our data suggest that natural gas drilling operationsmayresult in elevated endocrine-disrupting chemical activity in surface and ground water.

  9. On Ground Surface Extraction Using Full-Waveform Airborne Laser Scanner for Cim

    Science.gov (United States)

    Nakano, K.; Chikatsu, H.

    2015-05-01

    Satellite positioning systems such as GPS and GLONASS have created significant changes not only in terms of spatial information but also in the construction industry. It is possible to execute a suitable construction plan by using a computerized intelligent construction. Therefore, an accurate estimate of the amount of earthwork is important for operating heavy equipment, and measurement of ground surface with high accuracy is required. A full-waveform airborne laser scanner is expected to be capable of improving the accuracy of ground surface extraction for forested areas, in contrast to discrete airborne laser scanners, as technological innovation. For forested areas, fundamental studies for construction information management (CIM) were conducted to extract ground surface using full-waveform airborne laser scanners based on waveform information.

  10. ON GROUND SURFACE EXTRACTION USING FULL-WAVEFORM AIRBORNE LASER SCANNER FOR CIM

    Directory of Open Access Journals (Sweden)

    K. Nakano

    2015-05-01

    Full Text Available Satellite positioning systems such as GPS and GLONASS have created significant changes not only in terms of spatial information but also in the construction industry. It is possible to execute a suitable construction plan by using a computerized intelligent construction. Therefore, an accurate estimate of the amount of earthwork is important for operating heavy equipment, and measurement of ground surface with high accuracy is required. A full-waveform airborne laser scanner is expected to be capable of improving the accuracy of ground surface extraction for forested areas, in contrast to discrete airborne laser scanners, as technological innovation. For forested areas, fundamental studies for construction information management (CIM were conducted to extract ground surface using full-waveform airborne laser scanners based on waveform information.

  11. Fourier-transform spectroscopy of Sr2 and revised ground-state potential

    Science.gov (United States)

    Stein, A.; Knöckel, H.; Tiemann, E.

    2008-10-01

    Precise potentials for the ground-state XΣg+1 and the minimum region of the excited state 2Σu+1 of Sr2 are derived by high-resolution Fourier-transform spectroscopy of fluorescence progressions from single-frequency laser excitation of Sr2 produced in a heat pipe at 950°C . A change of the rotational assignment by four units compared to an earlier work [G. Gerber , J. Chem. Phys. 81, 1538 (1984)] is needed for a consistent description leading to a significant shift of the potentials toward longer interatomic distances. The huge amount of ground-state data derived for the three different isotopomers Sr288 , Sr86Sr88 , and Sr87Sr88 (almost 60% of all excisting bound rovibrational ground-state levels for the isotopomer Sr288 ) fixes this assignment beyond a doubt. The presented ground-state potential is derived from the observed transitions for the radial region from 4to11Å ( 9cm-1 below the asymptote) and is extended to the long-range region by the use of theoretical dispersion coefficients together with already available photoassociation data. New estimations of the scattering lengths for the complete set of isotopic combinations are derived by mass scaling with the derived potential. The data set for the excited state 2Σu+1 was sufficient to derive a potential energy curve around the minimum.

  12. Study on the applicability of frequency spectrum of micro-tremor and dynamic characteristics of surface ground in Asia area

    Institute of Scientific and Technical Information of China (English)

    CHE Ai-lan; IWATATE Takahiro; ODA Yoshiya; GE Xiu-run

    2006-01-01

    The dynamic characteristics of ground soil using micro-tremor observation in Asia (Zushi and Ogasawara (Japan),Xi'an (China), Manila (Philippines), and Gujarat (India)) are studied. Ground micro-tremor signals were observed and analyzed by fast Fourier transform method (FFT). The response of ground soil to frequency of ground micro-tremor is revealed, and functions with frequency-dependence and frequency-selection of micro-tremor for different foundation soil strata are also researched.The horizontal to vertical spectral ratio (H/V, Nakamura technique) of micro-tremor observed at the surface ground was used to evaluate the site's predominant period. This paper also discusses the application of micro-tremor on site safety evaluation, and gives the observed calculation results obtained at multiple points. The experimental foundation and the deduction process of the method are described in detail. Some problems of the method are pointed out. Potential use of the technique's good expandable nature makes it a useable means for preventing and reducing disaster's harmful effects.

  13. Van der Waals potential and vibrational energy levels of the ground state radon dimer

    Science.gov (United States)

    Sheng, Xiaowei; Qian, Shifeng; Hu, Fengfei

    2017-08-01

    In the present paper, the ground state van der Waals potential of the Radon dimer is described by the Tang-Toennies potential model, which requires five essential parameters. Among them, the two dispersion coefficients C6 and C8 are estimated from the well determined dispersion coefficients C6 and C8 of Xe2. C10 is estimated by using the approximation equation that C6C10 / C82 has an average value of 1.221 for all the rare gas dimers. With these estimated dispersion coefficients and the well determined well depth De and Re the Born-Mayer parameters A and b are derived. Then the vibrational energy levels of the ground state radon dimer are calculated. 40 vibrational energy levels are observed in the ground state of Rn2 dimer. The last vibrational energy level is bound by only 0.0012 cm-1.

  14. Topographical changes of ground surface affected by the Tarim Desert Highway

    Institute of Scientific and Technical Information of China (English)

    LI Shengyu; LEI Jiaqiang; XU Xinwen; WANG Lixin; ZHOU Zhibin; LI Hongzhong

    2006-01-01

    The Tarim Desert Highway is the longest highway crossing the mobile desert in the world. The highway and its sand protection system were established in 1995. This great project must have significant effect on the aeolian environment in its neighborhoods. In 2004, we investigated the topographic changes of ground surface within the sand protection system and its external adjacent area in the hinterland of the Taklimakan Desert. The results showed that (i) the original topographic patterns of ground surface were greatly changed, and erosion as well as deposition was distributed clearly on the ground surface, affected by the road and its sand protection system; (ii) sediment deposited in the sand protection system gradually heightened the ground surface, but each part in the system changed differently: in the sand-blocking belt, a transverse sand ridge was formed in the same direction as the upright sand barrier; in the sand-binding belt, sediment was aggraded on the original surface in a certain thickness; at the initial stages since the establishment of the sand protection system, erosion had taken place in the un-stabilized area named by the deposition belt between the sand-blocking belt and the sand-binding belt, the inner of sand-binding belt, the windward slope of dunes in the sand-binding belt, and the neighboring leeward area of the sand protection system.

  15. Ground surface thermal regime of rock glaciers in the High Tatra Mts., Slovakia

    Science.gov (United States)

    Uxa, Tomáš; Mida, Peter

    2017-04-01

    Numerous lobate- or tongue-shaped debris accumulations, mostly interpreted as rock glaciers, have recently been recognized in the High Tatra Mts., Slovakia (49˚ 10' N, 20˚ 08' E). These prominent landforms arise due to creep of voluminous debris-ice mixtures, and as such they are excellent indicators of present or past permafrost existence. Hence rock glaciers are extensively utilized to model the distribution of permafrost in mountain areas. However, commonly applied rules of thumb may not be entirely indicative to discriminate particularly between the inactive (permafrost in disequilibrium with present climate) and relict (without permafrost) rock glaciers, which may substantially complicate permafrost modelling. Accordingly, the information about their thermal state is essential to calibrate and validate regional permafrost models. Limited ground temperature data have been, however, available from the High Tatra Mts. to date and therefore, we bring the updated and enhanced results from the thermal investigations of eleven rock glaciers located in the Slavkovská dolina and Veľká Studená dolina valleys at elevations between 1832 and 2090 m asl. Ground surface temperature (GST) has been continuously monitored at seven rock glaciers between October 2014 and September 2016 using nine Minikin Tie (EMS Brno Inc.) and iButton DS1922L (Maxim Integrated Inc.) loggers with an accuracy of ±0.2 and ±0.5 ˚ C, respectively. In addition, the bottom temperature of snow (BTS) was measured at 306 locations during spring of 2015 and 2016 to map potential permafrost occurrence within all the surveyed rock glaciers and in their immediate surroundings. Mean annual ground surface temperature (MAGST) of the rock glaciers ranged between -1.3 ˚ C and +2.6 ˚ C and averaged +1.0 ˚ C and +0.8 ˚ C in 2014-2015 and 2015-2016, respectively. Two sites continually showed negative MAGST and two other sites were below +0.5 ˚ C and +1.0 ˚ C, respectively. This strongly contrasts with

  16. Potential suitable areas of giant ground sloths dropped before its extinction in South America

    DEFF Research Database (Denmark)

    Lima-Ribeiro, Matheus Souza; Varela, Sara; Nogues, David Bravo

    2012-01-01

    Here we analyze the effects that climatic changes through last ice age had on the potential distributions and extinction risk dynamics of two extinct species of South American giant ground sloths, Eremotherium laurillardi and Megatherium americanum. We tested the assumption of stability of the cl...

  17. A New Method for the Atomic Ground-State Energy in the Screened Coulomb Potential

    Institute of Scientific and Technical Information of China (English)

    YU Peng-Peng; GUO Hua

    2001-01-01

    The new method proposed recently by Friedberg,Lee and Zhao is applied to the derivation of the atomic ground-state energy with the inclusion of the screening effect.The present results are compared with those obtained in the pure Coulomb potential and by the variational approach.The overall good results are obtained with this new method.``

  18. Transport and fate of nitrate at the ground-water/surface-water interface

    Science.gov (United States)

    Puckett, L.J.; Zamora, C.; Essaid, H.; Wilson, J.T.; Johnson, H.M.; Brayton, M.J.; Vogel, J.R.

    2008-01-01

    Although numerous studies of hyporheic exchange and denitrification have been conducted in pristine, high-gradient streams, few studies of this type have been conducted in nutrient-rich, low-gradient streams. This is a particularly important subject given the interest in nitrogen (N) inputs to the Gulf of Mexico and other eutrophic aquatic systems. A combination of hydrologic, mineralogical, chemical, dissolved gas, and isotopic data, were used to determine the processes controlling transport and fate of NO3- in streambeds at five sites across the USA. Water samples were collected from streambeds at depths ranging from 0.3 to 3 m at three to five points across the stream and in two to five separate transects. Residence times of water ranging from 0.28 to 34.7 d m-1 in the streambeds of N-rich watersheds played an important role in allowing denitrification to decrease NO3- concentrations. Where potential electron donors were limited and residence times were short, denitrification was limited. Consequently, in spite of reducing conditions at some sites, NO3- was transported into the stream. At two of the five study sites, NO3- in surface water infiltrated the streambeds and concentrations decreased, supporting current models that NO3- would be retained in N-rich streams. At the other three study sites, hydrogeologic controls limited or prevented infiltration of surface water into the streambed, and ground-water discharge contributed to NO 3- loads. Our results also show that in these low hydrologic-gradient systems, storm and other high-flow events can be important factors for increasing surface-water movement into streambeds. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  19. Size of craters produced by explosive charges on or above the ground surface

    Science.gov (United States)

    Ambrosini, R. D.; Luccioni, B. M.; Danesi, R. F.; Riera, J. D.; Rocha, M. M.

    The results of a series of tests performed with different amounts of explosive at short distances above and below ground level, as well as on the soil surface are briefly described. After an introductory description of both the main features of the blast wave and the mechanics of crater formation, a brief review of empirical methods for crater size prediction is presented. Next, the experimental design and the results obtained are described. The crater dimensions for underground explosions coincide with those found in the literature. For explosions at ground level the results are qualitatively described by empirical equations. For explosive charges situated above ground level, the dimensions of the craters are smaller than those observed in underground and near the surface explosions. Two new single prediction equations for this case are presented.

  20. Ground squirrel shooting and potential lead exposure in breeding avian scavengers

    Science.gov (United States)

    Herring, Garth; Eagles-Smith, Collin A.; Wagner, Mason T.

    2016-01-01

    Recreational ground squirrel shooting is a popular activity throughout the western United States and serves as a tool for managing ground squirrel populations in agricultural regions. Belding’s ground squirrels (Spermophilus beldingi) are routinely shot in California, Nevada, and Oregon across habitats that overlap with breeding avian scavengers. Ground squirrels shot with lead (Pb)-based bullets may pose a risk to avian scavengers if they consume carcasses containing Pb fragments. To assess the potential risk to breeding avian scavengers we developed a model to estimate the number, mass, and distribution of Pb fragments in shot ground squirrels using radiographic images. Eighty percent of shot carcasses contained detectible Pb fragments with an average of 38.6 mg of Pb fragments. Seven percent of all carcasses contained Pb fragment masses exceeding a lethal dose for a model raptor nestling (e.g. American kestrel Falco sparverius). Bullet type did not influence the number of fragments in shot ground squirrels, but did influence the mass of fragments retained. Belding’s ground squirrels shot with .17 Super Mag and unknown ammunition types contained over 28 and 17 times more mass of Pb fragments than those shot with .22 solid and .22 hollow point bullets, respectively. Ground squirrel body mass was positively correlated with both the number and mass of Pb fragments in carcasses, increasing on average by 76% and 56% respectively across the range of carcass masses. Although the mass of Pb retained in ground squirrel carcasses was small relative to the original bullet mass, avian scavenger nestlings that frequently consume shot ground squirrels may be at risk for Pb-induced effects (e.g., physiology, growth, or survival). Using modeling efforts we found that if nestling golden eagles (Aquila chrysaetos), red-tailed hawks (Buteo jamaicensis), and Swainson’s hawks (B. swainsoni) consumed shot ground squirrels proportionately to the nestling’s mass, energy needs

  1. Inferring snow pack ripening and melt out from distributed ground surface temperature measurements

    Directory of Open Access Journals (Sweden)

    M.-O. Schmid

    2012-02-01

    Full Text Available The seasonal snow cover and its melting are heterogeneous both in space and time. Describing and modelling this variability are important because it affects divers phenomena such as runoff, ground temperatures or slope movements. This study investigates the derivation of melting characteristics based on spatial clusters of temperature measurements. Results are based on data from Switzerland where ground surface temperatures were measured with miniature loggers (iButtons at 40 locations, referred to as footprints. At each footprint, ten iButtons have been distributed randomly few cm below the ground surface over an area of 10 m × 10 m. Footprints span elevations of 2100–3300 m a.s.l. and slope angles of 0–55°, as well as diverse slope expositions and types of surface cover and ground material. Based on two years of temperature data, the basal ripening date and the melt-out date are determined for each iButton, aggregated to the footprint level and further analysed. The date of melt out could be derived for nearly all iButtons, the ripening date could be extracted for only approximately half of them because it requires ground freezing below the snow pack. The variability within a footprint is often considerable and one to three weeks difference between melting or ripening of the points in one footprint is not uncommon. The correlation of mean annual ground surface temperatures, ripening date and melt-out date is moderate, making them useful intuitive complementary measured for model evaluation.

  2. Supplementary report on surface-water and ground-water surveys, Nueces River Basin, Texas

    Science.gov (United States)

    Broadhurst, W.L.; Ellsworth, C.E.

    1950-01-01

    A report on the ground-water and surface-water surveys of the Nueces River Basin was included in a report by the Bureau of Reclamation, entitled "Comprehensive plan for water-resources development of the Nueces River Basin project planning report number 5-14.04-3, February 1946".

  3. Ground states for a modified capillary surface equation in weighted Orlicz-Sobolev space

    Directory of Open Access Journals (Sweden)

    Guoqing Zhang

    2015-03-01

    Full Text Available In this article, we prove a compact embedding theorem for the weighted Orlicz-Sobolev space of radially symmetric functions. Using the embedding theorem and critical points theory, we prove the existence of multiple radial solutions and radial ground states for the following modified capillary surface equation $$\\displaylines{ -\\operatorname{div}\\Big(\\frac{|\

  4. Assessment of potential strong ground motions in the city of Rome

    Directory of Open Access Journals (Sweden)

    L. Malagnini

    1994-06-01

    Full Text Available A methodology is used which combines stochastic generation of random series with a finite-difference technique to estimate the expected horizontal ground motion for the city of Rome as induced by a large earthquake in the Central Apennines. In this approach, source properties and long-path propagation are modelled through observed spectra of ground motion in the region, while the effects of the near-surface geology in the city are simulated by means of a finite-difference technique applied to 2-D models including elastic and anelastic properties of geologic materials and topographic variations. The parameters commonly used for earthquake engineering purposes are estimated from the simulated time histories of horizontal ground motion. We focus our attention on peak ground acceleration and velocity, and on the integral of the squared acceleration and velocity (that are proportional to the Arias intensity and seismic energy flux, respectively. Response spectra are analyzed as well. Parameter variations along 2-D profiles visualize the effects of the small-scale geological heterogeneities and topography irregularities on ground motion in the case of a strong earthquake. Interestingly, the largest amplification of peak ground acceleration and Arias intensity does not necessarily occur at the same sites where peak ground velocity and flux of seismic energy reach their highest values, depending on the frequency band of amplification. A magnitude 7 earthquake at a distance of 100 km results in peak ground accelerations ranging from 30 to 70 gals while peak ground velocities are estimated to vary from 5 to 7 cm/s; moreover, simulated time histories of horizontal ground motion yield amplitudes of 5% damped pseudovelocity response spectra as large as 15-20 cm/s for frequencies from 1to 3 Hz. In this frequency band, the mean value is 7 cm/s for firm sites and ranges from 10 to 13 cm/s for soil sites. All these results are in good agreement with predictions

  5. Reference springs in California for the regional ground-water potential map by Bedinger and Harrill (2004), Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital geospatial data set is a compilation of reference points representing springs in California that were used for the regional ground-water potential map...

  6. Reference springs in Nevada for the regional ground-water potential map by Bedinger and Harrill (2004), Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital geospatial data set is a compilation of reference points representing springs in Nevada that were used for the regional ground-water potential map by...

  7. Reference springs in Nevada for the regional ground-water potential map by Bedinger and Harrill (2004), Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital geospatial data set is a compilation of reference points representing springs in Nevada that were used for the regional ground-water potential map by...

  8. Structure and analytical potential energy function for the ground state of the BCx (x=0, -1)

    Institute of Scientific and Technical Information of China (English)

    Geng Zhen-Duo; Zhang Yan-Song; Fan Xiao-Wei; Lu Zhan-Sheng; Luo Gai-Xia

    2006-01-01

    In this paper, the electronic states of the ground states and dissociation limits of BC and BC- are correctly determined based on group theory and atomic and molecular reaction statics. The equilibrium geometries, harmonic frequencies and dissociation energies of the ground state of BC and BC- are calculated by using density function theory and quadratic CI method including single and double substitutions. The analytical potential energy functions of these states have been fitted with Murrell-Sorbie potential energy function from our ab initio calculation results. The spectroscopic data (αe, ωe and ωeXe) of each state is calculated via the relation between analytical potential energy function and spectroscopic data. All the calculations are in good agreement with the experimental data.

  9. Evaluation of the ground surface Enthalpy balance from bedrock shallow borehole temperatures (Livingston Island, Maritime Antarctic

    Directory of Open Access Journals (Sweden)

    M. Ramos

    2008-03-01

    Full Text Available The annual evolution of the ground temperatures from Incinerador borehole in Livingston Island (South Shetlands, Antarctic is studied. The borehole is 2.4 m deep and is located in a quartzite outcrop in the proximity of the Spanish Antarctic Station Juan Carlos I. In order to model the movement of the 0°C isotherm (velocity and maximum depth hourly temperature profiles from: (i the cooling periods of the frost seasons of 2000 to 2005, and (ii the warming periods of the thaw seasons of 2002–2003, 2003–2004 and 2004–2005, were studied. In this modelling approach, heat gains and losses across ground surface are considered to be the causes for the 0°C isotherm movement. A methodological approach to calculate the Enthalpy change based on the thermodynamic analysis of the ground during the cooling and warming periods is proposed. The Enthalpy change is equivalent to the heat exchange through the ground surface during each season, thus enabling to describe the interaction ground-atmosphere and providing valuable data for studies on permafrost and periglacial processes. The bedrock density is considered to be constant in the borehole and initial isothermal conditions at 0°C are assumed to run the model. The final stages correspond to the temperatures at the end of the cooling and warming periods (annual minima and maxima.

  10. Evaluation of the ground surface Enthalpy balance from bedrock shallow borehole temperatures (Livingston Island, Maritime Antarctic)

    Science.gov (United States)

    Ramos, M.; Vieira, G.

    2008-03-01

    The annual evolution of the ground temperatures from Incinerador borehole in Livingston Island (South Shetlands, Antarctic) is studied. The borehole is 2.4 m deep and is located in a quartzite outcrop in the proximity of the Spanish Antarctic Station Juan Carlos I. In order to model the movement of the 0°C isotherm (velocity and maximum depth) hourly temperature profiles from: (i) the cooling periods of the frost seasons of 2000 to 2005, and (ii) the warming periods of the thaw seasons of 2002-2003, 2003-2004 and 2004-2005, were studied. In this modelling approach, heat gains and losses across ground surface are considered to be the causes for the 0°C isotherm movement. A methodological approach to calculate the Enthalpy change based on the thermodynamic analysis of the ground during the cooling and warming periods is proposed. The Enthalpy change is equivalent to the heat exchange through the ground surface during each season, thus enabling to describe the interaction ground-atmosphere and providing valuable data for studies on permafrost and periglacial processes. The bedrock density is considered to be constant in the borehole and initial isothermal conditions at 0°C are assumed to run the model. The final stages correspond to the temperatures at the end of the cooling and warming periods (annual minima and maxima).

  11. Potential ground water resources of Hat Yai Basin in Peninsular Thailand by gravity study

    Directory of Open Access Journals (Sweden)

    Warawutti Lohawijarn

    2005-05-01

    Full Text Available Residual gravity anomaly with a minimum of about -140 mm s-2 with approximately NS trend and a limited axial length was observed over Hat Yai Basin in Peninsular Thailand. The modeled Hat Yai basin is about 1 km deep at its deepest, 60 km long and 20 km wide. The porosity of basin sediment and the amount of potential ground water reserves within the basin are estimated to be 39% and 121.7±0.8 km3 respectively, assuming full saturation. Within the topmost 80 m of ground where the present extraction is concentrated, the estimated ground water reserve is 12.5±0.5 km3.

  12. A new methodology for monitoring wood fluxes in rivers using a ground camera: Potential and limits

    Science.gov (United States)

    Benacchio, Véronique; Piégay, Hervé; Buffin-Bélanger, Thomas; Vaudor, Lise

    2017-02-01

    Ground imagery, which produces large amounts of valuable data at high frequencies, is increasingly used by fluvial geomorphologists to survey and understand processes. While such technology provides immense quantities of information, it can be challenging to analyze and requires automatization and associated development of new methodologies. This paper presents a new approach to automate the processing of image analysis to monitor wood delivery from the upstream Rhône River (France). The Génissiat dam is used as an observation window; all pieces of wood coming from the catchment are trapped here, hence a wood raft accumulates over time. In 2011, we installed an Axis 211W camera to acquire oblique images of the reservoir every 10 min with the goal of automatically detecting a wood raft area, in order to transform it to wood weight (t) and flux (t/d). The methodology we developed is based on random forest classification to detect the wood raft surface over time, which provided a good classification rate of 97.2%. Based on 14 mechanical wood extractions that included weight of wood removed each time, conducted during the survey period, we established a relationship between wood weight and wood raft surface area observed just before the extraction (R2 = 0.93). We found that using such techniques to continuously monitor wood flux is difficult because the raft undergoes very significant changes through time in terms of density, with a very high interday and intraday variability. Misclassifications caused by changes in weather conditions can be mitigated as well as errors from variation in pixel resolution (owing to camera position or window size), but a set of effects on raft density and mobility must still be explored (e.g., dam operation effects, wind on the reservoir surface). At this stage, only peak flow contribution to wood delivery can be well calculated, but determining an accurate, continuous series of wood flux is not possible. Several recommendations are

  13. Interannual changes in snow cover and its impact on ground surface temperatures in Livingston Island (Antarctica)

    Science.gov (United States)

    Nieuwendam, Alexandre; Ramos, Miguel; Vieira, Gonçalo

    2015-04-01

    In permafrost areas the seasonal snow cover is an important factor on the ground thermal regime. Snow depth and timing are important in ground insulation from the atmosphere, creating different snow patterns and resulting in spatially variable ground temperatures. The aim of this work is to characterize the interactions between ground thermal regimes and snow cover and the influence on permafrost spatial distribution. The study area is the ice-free terrains of northwestern Hurd Peninsula in the vicinity of the Spanish Antarctic Station "Juan Carlos I" and Bulgarian Antarctic Station "St. Kliment Ohridski". Air and ground temperatures and snow thickness data where analysed from 4 sites along an altitudinal transect in Hurd Peninsula from 2007 to 2012: Nuevo Incinerador (25 m asl), Collado Ramos (110 m), Ohridski (140 m) and Reina Sofia Peak (275 m). The data covers 6 cold seasons showing different conditions: i) very cold with thin snow cover; ii) cold with a gradual increase of snow cover; iii) warm with thick snow cover. The data shows three types of periods regarding the ground surface thermal regime and the thickness of snow cover: a) thin snow cover and short-term fluctuation of ground temperatures; b) thick snow cover and stable ground temperatures; c) very thick snow cover and ground temperatures nearly constant at 0°C. a) Thin snow cover periods: Collado Ramos and Ohridski sites show frequent temperature variations, alternating between short-term fluctuations and stable ground temperatures. Nuevo Incinerador displays during most of the winter stable ground temperatures; b) Cold winters with a gradual increase of the snow cover: Nuevo Incinerador, Collado Ramos and Ohridski sites show similar behavior, with a long period of stable ground temperatures; c) Thick snow cover periods: Collado Ramos and Ohridski show long periods of stable ground, while Nuevo Incinerador shows temperatures close to 0°C since the beginning of the winter, due to early snow cover

  14. A preliminary study on surface ground deformation near shallow foundation induced by strike-slip faulting

    Science.gov (United States)

    Wong, Pei-Syuan; Lin, Ming-Lang

    2016-04-01

    According to investigation of recent earthquakes, ground deformation and surface rupture are used to map the influenced range of the active fault. The zones of horizontal and vertical surface displacements and different features of surface rupture are investigated in the field, for example, the Greendale Fault 2010, MW 7.1 Canterbury earthquake. The buildings near the fault rotated and displaced vertically and horizontally due to the ground deformation. Besides, the propagation of fault trace detoured them because of the higher rigidity. Consequently, it's necessary to explore the ground deformation and mechanism of the foundation induced by strike-slip faulting for the safety issue. Based on previous study from scaled analogue model of strike-slip faulting, the ground deformation is controlled by material properties, depth of soil, and boundary condition. On the condition controlled, the model shows the features of ground deformation in the field. This study presents results from shear box experiment on small-scale soft clay models subjected to strike-slip faulting and placed shallow foundations on it in a 1-g environment. The quantifiable data including sequence of surface rupture, topography and the position of foundation are recorded with increasing faulting. From the result of the experiment, first en echelon R shears appeared. The R shears rotated to a more parallel angle to the trace and cracks pulled apart along them with increasing displacements. Then the P shears crossed the basement fault in the opposite direction appears and linked R shears. Lastly the central shear was Y shears. On the other hand, the development of wider zones of rupture, higher rising surface and larger the crack area on surface developed, with deeper depth of soil. With the depth of 1 cm and half-box displacement 1.2 cm, en echelon R shears appeared and the surface above the fault trace elevated to 1.15 mm (Dv), causing a 1.16 cm-wide zone of ground-surface rupture and deformation

  15. Ab initio adiabatic and quasidiabatic potential energy surfaces of H++ CN system

    Indian Academy of Sciences (India)

    Bhargava Anusuri; Sanjay Kumar

    2016-02-01

    We present restricted geometry (collinear and perpendicular approaches of proton) ab initio three dimensional potential energy surfaces for H++ CN system. The calculations were performed at the internally contracted multi-reference configuration interaction level of theory using Dunning’s correlation consistent polarized valence triple zeta basis set. Adiabatic and quasidiabatic surfaces have been computed for the ground and the first excited electronic states. Nonadiabatic effects arising from radial coupling have been analyzed in terms of nonadiabatic coupling matrix elements and coupling potentials.

  16. Seasonal Distribution of Trace Metals in Ground and Surface Water of Golaghat District, Assam, India

    Directory of Open Access Journals (Sweden)

    M. Boarh

    2010-01-01

    Full Text Available A study has been carried out on the quality of ground and surface water with respect to chromium, manganese, zinc, copper, nickel, cadmium and arsenic contamination from 28 different sources in the predominantly rural Golaghat district of Assam (India. The metals were analysed by using atomic absorption spectrometer. Water samples were collected from groundwater and surface water during the dry and wet seasons of 2008 from the different sources in 28 locations (samples. The results are discussed in the light of possible health hazards from the metals in relation to their maximum permissible limits. The study shows the quality of ground and surface water in a sizeable number of water samples in the district not to be fully satisfactory with respect to presence of the metals beyond permissible limits of WHO. The metal concentration of groundwater in the district follows the trend As>Zn>Mn>Cr>Cu>Ni>Cd in both the seasons.

  17. Ground-water, surface-water, and bottom-sediment contamination in the O-field area, Aberdeen Proving Ground, Maryland, and the possible effects of selected remedial actions on ground water

    Science.gov (United States)

    Vroblesky, Don A.; Lorah, Michelle M.; Oliveros, James P.

    1995-01-01

    Disposal of munitions and chemical-warfare substances has introduced inorganic and organic contaminants to the ground water, surface water, and bottom sediment at O-Field, in the Edgewood area of Aberdeen Proving Ground, Maryland. Contaminants include chloride, arsenic, transition metals, chlorinated aliphatic hydrocarbons, aromatic compounds, and organosulfur and organophosphorus compounds. The hydrologic effects of several remedial actions were estimated by use of a ground-water-flow model. The remedial actions examined were an impermeable covering, encapsulation, subsurface barriers, a ground-water drain, pumping of wells to manage water levels or to remove contaminated ground water for treatment, and no action.

  18. Binding of oxygen with titanium dioxide on singlet potential energy surface: An ab initio investigation

    Science.gov (United States)

    Bogdanchikov, Georgii A.; Baklanov, Alexey V.

    2017-01-01

    Ab initio calculations have been carried out to investigate interaction of titanium dioxide TiO2 with oxygen O2 in ground triplet and excited singlet states. On a singlet potential energy surface (PES) formation of a stable compound of titanium peroxide TiO4 is revealed which should appear in reaction of TiO2 with singlet oxygen without activation barrier. This peroxide is lower in energy than the ground state of two individual molecules TiO2 + 3O2 by 34.6 kcal/mol. Location of conical intersection between triplet and singlet PESs of TiO2sbnd O2 is also investigated.

  19. Determining the location of buried plastic water pipes from measurements of ground surface vibration

    Science.gov (United States)

    Muggleton, J. M.; Brennan, M. J.; Gao, Y.

    2011-09-01

    ‘Mapping the Underworld' is a UK-based project, which aims to create a multi-sensor device that combines complementary technologies for remote buried utility service detection and location. One of the technologies to be incorporated in the device is low-frequency vibro-acoustics, and techniques for detecting buried infrastructure, in particular plastic water pipes, are being investigated. One of the proposed techniques involves excitation of the pipe at some known location with concurrent vibrational mapping of the ground surface in order to infer the location of the remainder of the pipe. In this paper, measurements made on a dedicated pipe rig are reported. Frequency response measurements relating vibrational velocity on the ground to the input excitation were acquired. Contour plots of the unwrapped phase revealed the location of the pipe to within 0.1-0.2 m. Magnitude contour plots revealed the excitation point and also the location of the pipe end. By examining the unwrapped phase gradients along a line above the pipe, it was possible to identify the wave-type within the pipe responsible for the ground surface vibration. Furthermore, changes in the ground surface phase speed computed using this method enabled the location of the end of the pipe to be confirmed.

  20. Homogenization of seismic surface wave profiling in highly heterogeneous improved ground

    Science.gov (United States)

    Lin, C.; Chien, C.

    2012-12-01

    Seismic surface wave profiling is gaining popularity in engineering practice for determining shear-wave velocity profile since the two-station SASW (Spectral Analysis of Surface Wave) was introduced. Recent developments in the multi-station approach (Multi-station Analysis of Surface Wave, MASW) result in several convenient commercial tools. Unlike other geophysical tomography methods, the surface wave method is essentially a 1-D method assuming horizontally-layered medium. Nevertheless, MASW is increasingly used to map lateral variation of S-wave velocity by multiple surveys overlooking the effect of lateral heterogeneity. MASW typically requires long receiver spread in order to have enough depth coverage. The accuracy and lateral resolution of 2-D S-wave velocity imaging by surface wave is not clear. Many geotechnical applications involves lateral variation in a scale smaller than the geophone spread and wave length. For example, soft ground is often improved to increase strength and stiffness by methods such as jet grouting and stone column which result in heterogeneous ground with improved columns. Experimental methods (Standard Penetration Test, sampling and laboratory testing, etc.) used to assess such ground improvement are subjected to several limitations such as small sampling volume, time-consuming, and cost ineffectiveness. It's difficult to assess the average property of the improved ground and the actual replacement ratio of ground improvement. The use of seismic surface wave method for such a purpose seems to be a good alternative. But what MASW measures in such highly heterogeneous improved ground remains to be investigated. This study evaluated the feasibility of MASW in highly heterogeneous ground with improved columns and investigated the homogenization of shear wave velocity measured by MASW. Field experiments show that MASW testing in such a composite ground behaves similar to testing in horizontally layered medium. It seems to measure some sort

  1. Green's functions potential fields on surfaces

    CERN Document Server

    Melnikov, Yuri A

    2017-01-01

    This book is comprehensive in its classical mathematical physics presentation, providing the reader with detailed instructions for obtaining Green's functions from scratch. Green's functions is an instrument easily accessible to practitioners who are engaged in design and exploitation of machines and structures in modern engineering practice. To date, there are no books available on the market that are devoted to the Green's function formalism for equations covered in this volume. The reader, with an undergraduate background in applied mathematics, can become an active user of the Green's function approach. For the first time, Green's functions are discussed for a specific class of problems dealing with potential fields induced in thin-wall structures and therefore, the reader will have first-hand access to a novel issue. This Work is accessible to researchers in applied mathematics, mechanics, and relevant disciplines such as engineering, as well as to upper level undergraduates and graduate students.

  2. Potential energy surfaces of Polonium isotopes

    Science.gov (United States)

    Nerlo-Pomorska, B.; Pomorski, K.; Schmitt, C.; Bartel, J.

    2015-11-01

    The evolution of the potential energy landscape is analysed in detail for ten even-even polonium isotopes in the mass range 188\\lt A\\lt 220 as obtained within the macroscopic-microscopic approach, relying on the Lublin-Strasbourg drop model and the Yukawa-folded single-particle energies for calculating the microscopic shell and pairing corrections. A variant of the modified Funny-Hills nuclear shape parametrization is used to efficiently map possible fission paths. The approach explains the main features of the fragment partition as measured in low-energy fission along the polonium chain. The latter lies in a transitional region of the nuclear chart, and will be essential to consistently understand the evolution of fission properties from neutron-deficient mercury to heavy actinides. The ability of our method to predict fission observables over such an extended region looks promising.

  3. Impact of caprock permeability on vertical ground surface displacements in geological underground utilisation

    Science.gov (United States)

    Kempka, Thomas; Tillner, Elena

    2015-04-01

    Geological underground utilisation inducing pore pressure changes in underground reservoirs is generally accompanied by hydro-mechanical processes. Thereby, pore pressure increase due to fluid injection may trigger ground surface uplift, while a decrease in pore pressure due to reservoir fluid production is known to induce ground subsidence. Different coupled hydro-mechanical simulation studies (e.g. Klimkowski et al., 2015, Kempka et al., 2014, Tillner et al., 2014) indicate that ground surface displacements can achieve a magnitude of several decimetres, if storage or production operations are being carried out at an industrial scale. Consequently, detailed knowledge on the parameters impacting ground surface uplift or subsidence is of major interest for the success of any geological underground utilisation in order to avoid surface infrastructure damage by spatially varying deformations. Furthermore, ground subsidence may result increased groundwater levels as experienced in different underground coal mining districts. In the present study, we carried out coupled hydro-mechanical simulations to account for the impact of caprock permeability on ground surface displacements resulting from geological underground utilisation. Thereto, different simulation scenarios were investigated using a synthetic 3D coupled numerical simulation model with varying caprock permeability and vertical location of the open well section in the target reservoir. Material property ranges were derived from available literature, while a normal faulting stress state was applied in all simulation scenarios. Our simulation results demonstrate that caprock permeability has a significant impact on the pressure development, and thus on vertical displacements at the ground surface as well as at the reservoir top. An increase in caprock permeability from 1 x 10-20 m2 by two orders of magnitude doubles vertical displacements at the ground surface, whereas vertical displacements at the reservoir top

  4. Advantages of analytically computing the ground heat flux in land surface models

    Science.gov (United States)

    Pauwels, Valentijn R. N.; Daly, Edoardo

    2016-11-01

    It is generally accepted that the ground heat flux accounts for a significant fraction of the surface energy balance. In land surface models, the ground heat flux is typically estimated through a numerical solution of the heat conduction equation. Recent research has shown that this approach introduces errors in the estimation of the energy balance. In this paper, we calibrate a land surface model using a numerical solution of the heat conduction equation with four different vertical spatial resolutions. It is found that the thermal conductivity is the most sensitive parameter to the spatial resolution. More importantly, the thermal conductivity values are directly related to the spatial resolution, thus rendering any physical interpretation of this value irrelevant. The numerical solution is then replaced by an analytical solution. The results of the numerical and analytical solutions are identical when fine spatial and temporal resolutions are used. However, when using resolutions that are typical of land surface models, significant differences are found. When using the analytical solution, the ground heat flux is directly calculated without calculating the soil temperature profile. The calculation of the temperature at each node in the soil profile is thus no longer required, unless the model contains parameters that depend on the soil temperature, which in this study is not the case. The calibration is repeated, and thermal conductivity values independent of the vertical spatial resolution are obtained. The main conclusion of this study is that care must be taken when interpreting land surface model results that have been obtained using numerical ground heat flux estimates. The use of exact analytical solutions, when available, is recommended.

  5. Evaluation of the ground surface Enthalpy balance from bedrock temperatures (Livingston Island, Maritime Antarctic)

    Science.gov (United States)

    Ramos, M.; Vieira, G.

    2009-05-01

    The annual evolution of the ground temperatures from Incinerador borehole in Livingston Island (South Shetlands, Antarctic) is studied. The borehole is 2.4 m deep and is located in a massive quartzite outcrop with negligible water content, in the proximity of the Spanish Antarctic Station Juan Carlos I. In order to model the movement of the 0°C isotherm (velocity and maximum depth) hourly temperature profiles from: (i) the cooling periods of the frost season of 2000 to 2005, and (ii) the warming periods of the thaw season of 2002-2003, 2003-2004 and 2004-2005, were studied. In this modelling approach, heat gains and losses across the ground surface are assumed to be the causes for the 0°C isotherm movement. A methodological approach to calculate the ground Enthalpy change based on the thermodynamic analysis of the ground during the cooling and warming periods is proposed. The Enthalpy change into the rock is equivalent to the heat exchange through the ground surface during each season, thus enabling to describe the interaction ground-atmosphere and providing valuable data for studies on permafrost and periglacial processes. The bedrock density and thermal conductivity are considered to be constant and initial isothermal conditions at 0°C are assumed (based in collected data and local meteorological conditions in this area) to run the model in the beginning of each season. The final stages correspond to the temperatures at the end of the cooling and warming periods (annual minima and maxima). The application of this method avoids error propagation induced by the heat exchange calculations from multiple sensors using the Fourier method.

  6. Evaluation of the ground surface Enthalpy balance from bedrock temperatures (Livingston Island, Maritime Antarctic

    Directory of Open Access Journals (Sweden)

    M. Ramos

    2009-05-01

    Full Text Available The annual evolution of the ground temperatures from Incinerador borehole in Livingston Island (South Shetlands, Antarctic is studied. The borehole is 2.4 m deep and is located in a massive quartzite outcrop with negligible water content, in the proximity of the Spanish Antarctic Station Juan Carlos I. In order to model the movement of the 0°C isotherm (velocity and maximum depth hourly temperature profiles from: (i the cooling periods of the frost season of 2000 to 2005, and (ii the warming periods of the thaw season of 2002–2003, 2003–2004 and 2004–2005, were studied. In this modelling approach, heat gains and losses across the ground surface are assumed to be the causes for the 0°C isotherm movement. A methodological approach to calculate the ground Enthalpy change based on the thermodynamic analysis of the ground during the cooling and warming periods is proposed. The Enthalpy change into the rock is equivalent to the heat exchange through the ground surface during each season, thus enabling to describe the interaction ground-atmosphere and providing valuable data for studies on permafrost and periglacial processes. The bedrock density and thermal conductivity are considered to be constant and initial isothermal conditions at 0°C are assumed (based in collected data and local meteorological conditions in this area to run the model in the beginning of each season. The final stages correspond to the temperatures at the end of the cooling and warming periods (annual minima and maxima. The application of this method avoids error propagation induced by the heat exchange calculations from multiple sensors using the Fourier method.

  7. Ground-State Ionization Potentials for Lithium through Neon Isoelectronic Sequences with Z=37-82

    Institute of Scientific and Technical Information of China (English)

    HUANG Jie; JIANG Gang; ZHAO Qian

    2006-01-01

    The ground-state ionization potentials of different isoelectronic sequences are calculated systemically with the multi-configuration Dirac-Fock method.The relativistic corrections,Breit and QED effects are included in the calculation.These results are compared with the scanty existing theoretical and experimental data in the literature.Analytical expressions are obtained for expressing our theoretical data along the different sequences.

  8. Multiplicity of ground state solutions for discrete nonlinear Schrodinger equations with unbounded potentials

    Directory of Open Access Journals (Sweden)

    Xia Liu

    2017-02-01

    Full Text Available The discrete nonlinear Schrodinger equation is a nonlinear lattice system that appears in many areas of physics such as nonlinear optics, biomolecular chains and Bose-Einstein condensates. In this article, we consider a class of discrete nonlinear Schrodinger equations with unbounded potentials. We obtain some new sufficient conditions on the multiplicity results of ground state solutions for the equations by using the symmetric mountain pass lemma. Recent results in the literature are greatly improved.

  9. Ground surface temperature and humidity, ground temperature cycles and the ice table depths in University Valley, McMurdo Dry Valleys of Antarctica

    Science.gov (United States)

    Fisher, David A.; Lacelle, Denis; Pollard, Wayne; Davila, Alfonso; McKay, Christopher P.

    2016-11-01

    In the upper McMurdo Dry Valleys, 90% of the measured ice table depths range from 0 to 80 cm; however, numerical models predict that the ice table is not in equilibrium with current climate conditions and should be deeper than measured. This study explored the effects of boundary conditions (air versus ground surface temperature and humidity), ground temperature cycles, and their diminishing amplitude with depth and advective flows (Darcy flow and wind pumping) on water vapor fluxes in soils and ice table depths using the REGO vapor diffusion model. We conducted a series of numerical experiments that illustrated different hypothetical scenarios and estimated the water vapor flux and ice table depth using the conditions in University Valley, a small high elevation valley. In situ measurements showed that while the mean annual ground surface temperature approximates that in the air, the mean annual ground surface relative humidity (>85%ice) was significantly higher than in the atmosphere ( 50%ice). When ground surface temperature and humidity were used as boundary conditions, along with damping diurnal and annual temperature cycles within the sandy soil, REGO predicted that measured ice table depths in the valley were in equilibrium with contemporary conditions. Based on model results, a dry soil column can become saturated with ice within centuries. Overall, the results from the new soil data and modeling have implications regarding the factors and boundary conditions that affect the stability of ground ice in cold and hyperarid regions where liquid water is rare.

  10. Kinetics of the forelimb in horses circling on different ground surfaces at the trot.

    Science.gov (United States)

    Chateau, Henry; Camus, Mathieu; Holden-Douilly, Laurène; Falala, Sylvain; Ravary, Bérangère; Vergari, Claudio; Lepley, Justine; Denoix, Jean-Marie; Pourcelot, Philippe; Crevier-Denoix, Nathalie

    2013-12-01

    Circling increases the expression of distal forelimb lameness in the horse, depending on rein, diameter and surface properties of the circle. However, there is limited information about the kinetics of horses trotting on circles. The aim of this study was to quantify ground reaction force (GRF) and moments in the inside and outside forelimb of horses trotting on circles and to compare the results obtained on different ground surfaces. The right front hoof of six horses was equipped with a dynamometric horseshoe, allowing the measurement of 3-dimensional GRF, moments and trajectory of the centre of pressure. The horses were lunged at slow trot (3 m/s) on right and left 4 m radius circles on asphalt and on a fibre sand surface. During circling, the inside forelimb produced a smaller peak vertical force and the stance phase was longer in comparison with the outside forelimb. Both right and left circling produced a substantial transversal force directed outwards. On a soft surface (sand fibre), the peak transversal force and moments around the longitudinal and vertical axes of the hoof were significantly decreased in comparison with a hard surface (asphalt). Sinking of the lateral or medial part of the hoof in a more compliant surface enables reallocation of part of the transversal force into a proximo-distal force, aligned with the limb axis, thus limiting extrasagittal stress on the joints.

  11. Ground States for the Schrödinger Systems with Harmonic Potential and Combined Power-Type Nonlinearities

    Directory of Open Access Journals (Sweden)

    Baiyu Liu

    2014-01-01

    Full Text Available We consider a class of coupled nonlinear Schrödinger systems with potential terms and combined power-type nonlinearities. We establish the existence of ground states, by using a variational method. As an application, some symmetry results for ground states of Schrödinger systems with harmonic potential terms are obtained.

  12. Potential suitable areas of giant ground sloths dropped before its extinction in South America

    DEFF Research Database (Denmark)

    Lima-Ribeiro, Matheus Souza; Varela, Sara; Nogues, David Bravo;

    2012-01-01

    Here we analyze the effects that climatic changes through last ice age had on the potential distributions and extinction risk dynamics of two extinct species of South American giant ground sloths, Eremotherium laurillardi and Megatherium americanum. We tested the assumption of stability...... of the climate change, although do not support it as the unique stressor...... of the climate preferences through time for the two species and modeled their potential distributions at last glacial maximum (LGM, 21 ky BP) and mid-Holocene (6 ky BP) using Bioclimatic Envelope Modeling (BEM), fossil records and paleoclimatic simulations. The model predictions showed a drastic reduction...

  13. New Measurements from Old Boreholes: A Look at Interaction Between Surface Air Temperature and Ground Surface Temperature

    Science.gov (United States)

    Heinle, S. M.; Gosnold, W. D.

    2007-12-01

    We recently logged new field measurements of several boreholes throughout the Midwest, including North Dakota, South Dakota, and Nebraska. We then compared these new measurements against measurements previously obtained. Our comparisons included inverse modeling of past and recent measurements as well as climate modeling based on past surface air temperatures obtained from the weather stations. The data show a good correlation between climate warming in the last century and ground surface warming. Of particular importance is that cooling of air temperatures beginning in the mid 1990s reflects in the ground surface temperatures. The boreholes included in the study consist of three boreholes located in north central North Dakota, including two deeper than 200 meters. Two boreholes in the southwestern part of South Dakota, and two from southeastern South Dakota, all approximately 180 meters deep. Also included, were two boreholes (135 meters and over 200 meters deep) located in southwestern Nebraska, and two boreholes in the panhandle of Nebraska, each over 100 meters deep. We obtained historical surface air temperature from climate stations located near the boreholes, both from the United States Historical Climatology Network and from the Western Regional Climate Center.

  14. ON GROUND SURFACE EXTRACTION USING FULL-WAVEFORM AIRBORNE LASER SCANNER FOR CIM

    OpenAIRE

    Nakano, K.; H. Chikatsu

    2015-01-01

    Satellite positioning systems such as GPS and GLONASS have created significant changes not only in terms of spatial information but also in the construction industry. It is possible to execute a suitable construction plan by using a computerized intelligent construction. Therefore, an accurate estimate of the amount of earthwork is important for operating heavy equipment, and measurement of ground surface with high accuracy is required. A full-waveform airborne laser scanner is expected to be...

  15. Efficiency of silver nanoparticles against bacterial contaminants isolated from surface and ground water in Egypt

    Directory of Open Access Journals (Sweden)

    Reem Dosoky

    2015-06-01

    Full Text Available The bactericidal efficiency of silver nanoparticles (AgNP was evaluated against bacteria isolated from surface and ground water samples in Egypt. The AgNP were synthesized by typical one-step synthesis protocol, and were characterized using transmission electron microscopy and atomic absorption spectrophotometer. The bactericidal efficiency of AgNP was evaluated by its application in three concentrations i.e., 0.1, 0.05 and 0.01 ppm to water sample, and allowed to interact with bacteria for different duration e.g., 5 min 15 min, 30 min, 1 h and 2 h. Then, the bactericidal efficiency of AgNPs was determined by comparing the counted bacteria before and after the treatments. Higher mean values of total bacterial count (TBC, total coliform count (TCC, and total streptococcal count (TFS were detected in surface water than in ground water. Also, the results showed that TBC, TCC and TFS exceeded permissible limits. Application of AgNP at different concentration, the number of bacteria in TBC was significantly reduced in all AgNP-exposed samples as compared to the control group (p<0.05. The highest concentration of AgNP exhibited highest bactericidal efficiency in TBC, where, after two hours, 0.1, 0.05 and 0.01 mg/L AgNP was found to be sufficient to inhibit 91.85, 89.14 and 74.92%, and 92.33, 85.23 and 53.17% in TBC of surface and ground water, respectively. Moreover, the inhibition efficiency of the highest concentration (0.1 ppm against TCC reached to 98.10 and 99.88% in surface water and 95.54 and 99.20% in ground water after 1 h and 2 h, respectively. Similar results were found against TFS count. The AgNPs were found to be effective against bacteria of water origin.

  16. Ground state and orbital stability for the NLS equation on a general starlike graph with potentials

    Science.gov (United States)

    Cacciapuoti, Claudio; Finco, Domenico; Noja, Diego

    2017-08-01

    We consider a nonlinear Schrödinger equation (NLS) posed on a graph (or network) composed of a generic compact part to which a finite number of half-lines are attached. We call this structure a starlike graph. At the vertices of the graph interactions of δ-type can be present and an overall external potential is admitted. Under general assumptions on the potential, we prove that the NLS is globally well-posed in the energy domain. We are interested in minimizing the energy of the system on the manifold of constant mass (L 2-norm). When existing, the minimizer is called ground state and it is the profile of an orbitally stable standing wave for the NLS evolution. We prove that a ground state exists for sufficiently small masses whenever the quadratic part of the energy admits a simple isolated eigenvalue at the bottom of the spectrum (the linear ground state). This is a wide generalization of a result previously obtained for a star-graph with a single vertex. The main part of the proof is devoted to prove the concentration compactness principle for starlike structures; this is non trivial due to the lack of translation invariance of the domain. Then we show that a minimizing, bounded, H 1 sequence for the constrained NLS energy with external linear potentials is in fact convergent if its mass is small enough. Moreover we show that the ground state bifurcates from the vanishing solution at the bottom of the linear spectrum. Examples are provided with a discussion of the hypotheses on the linear part.

  17. Getting saturated hydraulic conductivity from surface Ground-Penetrating Radar measurements inside a ring infiltrometer

    Science.gov (United States)

    Leger, E.; Saintenoy, A.; Coquet, Y.

    2013-12-01

    Hydraulic properties of soils, described by the soil water retention and hydraulic conductivity functions, strongly influence water flow in the vadoze zone, as well as the partitioning of precipitation between infiltration into the soil and runoff along the ground surface. Their evaluation has important applications for modelling available water resources and for flood forecasting. It is also crucial to evaluate soil's capacity to retain chemical pollutants and to assess the potential of groundwater pollution. The determination of the parameters involved in soil water retention functions, 5 parameters when using the van Genuchten function, is usually done by laboratory experiments, such as the water hanging column. Hydraulic conductivity, on the other hand can be estimated either in laboratory, or in situ using infiltrometry tests. Among the large panel of existing tests, the single or double ring infiltrometers give the field saturated hydraulic conductivity by applying a positive charge on soils, whereas the disk infiltrometer allows to reconstruct the whole hydraulic conductivity curve, by applying different charges smaller than or equal to zero. In their classical use, volume of infiltrated water versus time are fitted to infer soil's hydraulic conductivity close to water saturation. Those tests are time-consuming and difficult to apply to landscape-scale forecasting of infiltration. Furthermore they involve many assumptions concerning the form of the infiltration bulb and its evolution. Ground-Penetrating Radar (GPR) is a geophysical method based on electromagnetic wave propagation. It is highly sensitive to water content variations directly related to the dielectric permittivity. In this study GPR was used to monitor water infiltration inside a ring infiltrometer and retrieve the saturated hydraulic conductivity. We carried out experiments in a quarry of Fontainebleau sand, using a Mala RAMAC system with antennae centered on 1600 MHz. We recorded traces at

  18. Derivation of Ground Surface and Vegetation in a Coastal Florida Wetland with Airborne Laser Technology

    Science.gov (United States)

    Raabe, Ellen A.; Harris, Melanie S.; Shrestha, Ramesh L.; Carter, William E.

    2008-01-01

    The geomorphology and vegetation of marsh-dominated coastal lowlands were mapped from airborne laser data points collected on the Gulf Coast of Florida near Cedar Key. Surface models were developed using low- and high-point filters to separate ground-surface and vegetation-canopy intercepts. In a non-automated process, the landscape was partitioned into functional landscape units to manage the modeling of key landscape features in discrete processing steps. The final digital ground surface-elevation model offers a faithful representation of topographic relief beneath canopies of tidal marsh and coastal forest. Bare-earth models approximate field-surveyed heights by + 0.17 m in the open marsh and + 0.22 m under thick marsh or forest canopy. The laser-derived digital surface models effectively delineate surface features of relatively inaccessible coastal habitats with a geographic coverage and vertical detail previously unavailable. Coastal topographic details include tidal-creek tributaries, levees, modest topographic undulations in the intertidal zone, karst features, silviculture, and relict sand dunes under coastal-forest canopy. A combination of laser-derived ground-surface and canopy-height models and intensity values provided additional mapping capabilities to differentiate between tidal-marsh zones and forest types such as mesic flatwood, hydric hammock, and oak scrub. Additional derived products include fine-scale shoreline and topographic profiles. The derived products demonstrate the capability to identify areas of concern to resource managers and unique components of the coastal system from laser altimetry. Because the very nature of a wetland system presents difficulties for access and data collection, airborne coverage from remote sensors has become an accepted alternative for monitoring wetland regions. Data acquisition with airborne laser represents a viable option for mapping coastal topography and for evaluating habitats and coastal change on marsh

  19. A new formulation to compute self-potential signals associated with ground water flow

    Directory of Open Access Journals (Sweden)

    A. Bolève

    2007-06-01

    Full Text Available The classical formulation of the coupled hydroelectrical flow in porous media is based on a linear formulation of two coupled constitutive equations for the electrical current density and the seepage velocity of the water phase and obeying Onsager's reciprocity. This formulation shows that the streaming current density is controlled by the gradient of the fluid pressure of the water phase and a streaming current coupling coefficient that depends on the so-called zeta potential. Recently a new formulation has been introduced in which the streaming current density is directly connected to the seepage velocity of the water phase and to the excess of electrical charge per unit pore volume in the porous material. The advantages of this formulation are numerous. First this new formulation is more intuitive not only in terms of constitutive equation for the generalized Ohm's law but also in specifying boundary conditions for the influence of the flow field upon the streaming potential. With the new formulation, the streaming potential coupling coefficient shows a decrease of its magnitude with permeability in agreement with published results. The new formulation is also easily extendable to non-viscous laminar flow problems (high Reynolds number ground water flow in cracks for example and to unsaturated conditions with applications to the vadose zone. We demonstrate here that this formulation is suitable to model self-potential signals in the field. We investigate infiltration of water from an agricultural ditch, vertical infiltration of water into a sinkhole, and preferential horizontal flow of ground water in a paleochannel. For the three cases reported in the present study, a good match is obtained between the finite element simulations performed with the finite element code Comsol Multiphysics 3.3 and field observations. Finally, this formulation seems also very promising for the inversion of the geometry of ground water flow from the

  20. Common ground on surgical abortion?--engaging Peter Singer on the moral status of potential persons.

    Science.gov (United States)

    Camosy, Charles C

    2008-12-01

    The debate over surgical abortion is certainly one of the most divisive in ethical discourse and for many it seems interminable. However, this paper argues that a primary reason for this is confusion with regard to what issues are actually under dispute. When looking at an entrenched and articulate figure on one side of the debate, Peter Singer, and comparing his views with those of his opponents, one finds that the disputed issue is actually quite a narrow one: the moral status of potential persons. Finding this common ground clears the conceptual space for a fruitful argument: the thesis of which is that most, including Singer, who argue that potential persons do not have full personal moral status fail to make the necessary distinction between natural potential (which confers moral status) and practical potential (which admittedly does not).

  1. Modeling ground surface uplift during CO2 sequestration: the case of In Salah, Algeria.

    Science.gov (United States)

    Rinaldi, Antonio Pio; Rutqvist, Jonny; Finsterle, Stefan; Liu, Hui-Hai

    2016-04-01

    Observable ground deformation, common in storage projects, carries useful information on processes occurring at the injection depth. The Krechba gas field at In Salah (Algeria) is one of the best known sites for studying ground surface deformation during geological storage. Being the first industrial-scale on-shore CO2 demonstration project, the site is well known for satellite-based ground-deformation monitoring data of remarkable quality. In this work, we carry out coupled fluid flow and geomechanical simulations to understand the uplift at three different CO2 injection wells (KB-501, KB-502, KB-503). Previous numerical studies focused on the KB-502 injection well, where a double-lobe uplift pattern has been observed in the ground-deformation data. The observed uplift patterns at KB-501 and KB-503 are different, but also indicate the influence of deep fracture zone mechanical responses. The current study improves the previous modeling approach by introducing an injection reservoir and a fracture zone, both responding to a Mohr-Coulomb failure criterion. In addition, we model a stress-dependent permeability and bulk modulus, according to a dual continuum model. Mechanical and hydraulic properties were determined through inverse modeling by matching the simulated spatial and temporal evolution of uplift to the corresponding InSAR observations as well as by matching simulated and measured pressures. The numerical simulations are in excellent agreement with observed spatial and temporal variation of ground surface uplift, as well as with measured pressures. The estimated values for the parameterized mechanical and hydraulic properties are in good agreement with previous numerical results, although with uncertainty.

  2. Ground-coupled airwaves at Pavlof Volcano, Alaska, and their potential for eruption monitoring

    Science.gov (United States)

    Smith, Cassandra M.; McNutt, Stephen R.; Thompson, Glenn

    2016-07-01

    An abnormally high number of explosion quakes were noted during the monitoring effort for the 2007 eruption of Pavlof Volcano on the Alaska Peninsula. In this study, we manually cataloged the explosion quakes from their characteristic ground-coupled airwaves. This study investigates how the ground-coupled airwaves might be used in a monitoring or analysis effort by estimating energy release and gas mass release. Over 3 × 104 quakes were recorded. The energy release from the explosions is approximated to be 3 × 1011 J, and the total gas mass (assuming 100 % water) released was 450 t. The tracking of explosion quakes has the potential to estimate relative eruption intensity as a function of time and is thus a useful component of a seismic monitoring program.

  3. Analytical Potential Energy Function for the Ground State X1∑+ of Lanthanum Monofluoride

    Institute of Scientific and Technical Information of China (English)

    CHEN Lin-Hong; SHANG Ren-Cheng

    2003-01-01

    The equilibrium geometry, harmonic frequency and bond dissociation energy of lanthanum monofluoride have been calculated using Density-Functional Theory (DFT), post-HF methods MP2 and CCSD(T) with the energyconsistent relativistic effective core potentials. The possible electronic state and reasonable dissociation limit of the ground state of LaF are determined based on atomic and molecular reaction statics. Potential energy curve scans for the ground state X 1∑+ have been performed at B3LYP and CCSD(T) levels, due to their better results of harmonic frequency and bond dissociation energy. We find that the potential energy calculated with CCSD(T) is about 0.6 eV larger than the bond dissociation energy, when the internuclear distance is as large as 0.8 nm. The problem that single-reference ab initio methods do not meet dissociation limit during calculations of lanthanide heavy-metal elements is analyzed. We propose the calculation scheme to derive the analytical Murrell-Sorbie potential energy function. Vibrotational spectroscopic constants Be, ωe, ωeχe, αe, βe, De and He obtained by the standard Dunham treatment coincide well with the results of rotational analyses on spectroscopic experiments.

  4. Effect of electric potential and heating on surface of KCI

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ The purpose of the work is research of morphology of structural changes of a surface { 100} crystals KCl under action of heating and electric field potential enclosed to one of fasets of a crystal.

  5. Effect of electric potential and heating on surface of KCI

    Institute of Scientific and Technical Information of China (English)

    Feodorov; Victor; A.; Sterelukhin; Andrey; A.; Karyev; Leonid; G.

    2005-01-01

    The purpose of the work is research of morphology of structural changes of a surface { 100} crystals KCl under action of heating and electric field potential enclosed to one of fasets of a crystal.……

  6. Determination of Land Surface Temperature (LST) and Potential ...

    African Journals Online (AJOL)

    Determination of Land Surface Temperature (LST) and Potential Urban Heat Island Effect in Parts of Lagos State using Satellite ... Changes in temperature appear to be closely related to concentrations of atmospheric carbon dioxide.

  7. Surface Gap Soliton Ground States for the Nonlinear Schr\\"{o}dinger Equation

    CERN Document Server

    Dohnal, Tomáš; Reichel, Wolfgang

    2010-01-01

    We consider the nonlinear Schr\\"{o}dinger equation $(-\\Delta +V(x))u = \\Gamma(x) |u|^{p-1}u$, $x\\in \\R^n$ with $V(x) = V_1(x) \\chi_{\\{x_1>0\\}}(x)+V_2(x) \\chi_{\\{x_10\\}}(x)+\\Gamma_2(x) \\chi_{\\{x_1<0\\}}(x)$ and with $V_1, V_2, \\Gamma_1, \\Gamma_2$ periodic in each coordinate direction. This problem describes the interface of two periodic media, e.g. photonic crystals. We study the existence of ground state $H^1$ solutions (surface gap soliton ground states) for $0<\\min \\sigma(-\\Delta +V)$. Using a concentration compactness argument, we provide an abstract criterion for the existence based on ground state energies of each periodic problem (with $V\\equiv V_1, \\Gamma\\equiv \\Gamma_1$ and $V\\equiv V_2, \\Gamma\\equiv \\Gamma_2$) as well as a more practical criterion based on ground states themselves. Examples of interfaces satisfying these criteria are provided. In 1D it is shown that, surprisingly, the criteria can be reduced to conditions on the linear Bloch waves of the operators $-\\tfrac{d^2}{dx^2} +V_1(x)$ an...

  8. Surface properties of a single perfluoroalkyl group on water surfaces studied by surface potential measurements.

    Science.gov (United States)

    Shimoaka, Takafumi; Tanaka, Yuki; Shioya, Nobutaka; Morita, Kohei; Sonoyama, Masashi; Amii, Hideki; Takagi, Toshiyuki; Kanamori, Toshiyuki; Hasegawa, Takeshi

    2016-12-01

    A discriminative study of a single perfluoroalkyl (Rf) group from a bulk material is recently recognized to be necessary toward the total understanding of Rf compounds based on a primary chemical structure. The single molecule and the bulk matter have an interrelationship via an intrinsic two-dimensional (2D) aggregation property of an Rf group, which is theorized by the stratified dipole-arrays (SDA) theory. Since an Rf group has dipole moments along many C-F bonds, a single Rf group would possess a hydrophilic-like character on the surface. To reveal the hydration character of a single Rf group, in the present study, surface potential (ΔV) measurements are performed for Langmuir monolayers of Rf-containing compounds. From a comparative study with a monolayer of a normal hydrocarbon compound, the hydration/dehydration dynamics of a lying Rf group on water has first been monitored by ΔV measurements, through which a single Rf group has been revealed to have a unique "dipole-interactive" character, which enables the Rf group interacted with the water 'surface.' In addition, the SDA theory proves to be useful to predict the 2D aggregation property across the phase transition temperature of 19°C by use of the ΔV measurements.

  9. Influence of Holocene stratigraphic architecture on ground surface settlements: A case study from the City of Pisa (Tuscany, Italy)

    Science.gov (United States)

    Sarti, Giovanni; Rossi, Veronica; Amorosi, Alessandro

    2012-12-01

    The Holocene stratigraphic architecture of modern coastal and deltaic plains has peculiar characteristics that may influence ground surface settlements. In the Pisa urban area, the inhomogeneous spatial distribution of geotechnically weak layers, typically formed during the mid-late Holocene (highstand) coastal progradation, is inferred to be responsible for urban ground settlement and building damage, as evidenced by the tilt of several surface structures, among which the famous Leaning Tower of Pisa is the most prominent. On the basis of integrated stratigraphic, sedimentological and geotechnical data from a wide georeferenced database, three facies associations with high deformability potential (Units 1-3) are identified in the uppermost 30 m as opposed to depositional facies (Units 4-5) with higher geotechnical strength. Whereas Unit 1 represents a thick, laterally extensive lagoonal clay deposit, the overlying highly deformable units (Units 2-3) show more discontinuous spatial distribution controlled by the Holocene paleohydrographic evolution of the Arno coastal plain. Unit 2, dated between the Neolithic and the Etruscan age (ca. 5000-2000 yr BP), is composed of swamp clays and silty clays recording lagoon infilling due to Arno Delta progradation. Units 3 and 4, which consist of wet levee deposits and stiff floodplain clays, respectively, formed during the subsequent phases of alluvial plain construction started around the Roman age (from ca. 2000 yr BP). Whereas Units 3 and 4 are recorded within the uppermost 5 m, fluvial and distributary channel sands (Unit 5) cut the underlying deltaic-alluvial succession at various stratigraphic levels, down to Unit 1. The spatial distribution of these units gives rise to three, locally juxtaposed, stratigraphic motifs in Pisa underground, reflecting different potential risks for settlement under building loads. We show how lateral changes in stratigraphic architecture account for the irregular spatial distribution of

  10. Relationship between subsurface damage and surface roughness of ground optical materials

    Institute of Scientific and Technical Information of China (English)

    LI Sheng-yi; WANG Zhuo; WU Yu-lie

    2007-01-01

    A theoretical model of relationship between subsurface damage and surface roughness was established to realize rapid and non-destructive measurement of subsurface damage of ground optical materials. Postulated condition of the model was that subsurface damage depth and peak-to-valley surface roughness are equal to depth of radial and lateral cracks in brittle surface induced by small-radius (radius≤200 μm) spherical indenter, respectively. And contribution of elastic stress field to the radial cracks propagation was also considered in the loading cycle. Subsurface damage depth of ground BK7 glasses was measured by magnetorheological finishing spot technique to validate theoretical ratio of subsurface damage to surface roughness. The results show that the ratio is directly proportional to load of abrasive grains and hardness of optical materials, while inversely proportional to granularity of abrasive grains and fracture toughness of optical materials. Moreover, the influence of the load and fracture toughness on the ratio is more significant than the granularity and hardness, respectively. The measured ratios of 80 grit and 120 grit fixed abrasive grinding of BK7 glasses are 5.8 and 5.4, respectively.

  11. Environmental impact of highway construction and repair materials on surface and ground waters. Case study: crumb rubber asphalt concrete.

    Science.gov (United States)

    Azizian, Mohammad F; Nelson, Peter O; Thayumanavan, Pugazhendhi; Williamson, Kenneth J

    2003-01-01

    The practice of incorporating certain waste products into highway construction and repair materials (CRMs) has become more popular. These practices have prompted the National Academy of Science, National Cooperative Highway Research Program (NCHRP) to research the possible impacts of these CRMs on the quality of surface and ground waters. State department of transportations (DOTs) are currently experimenting with use of ground tire rubber ( crumb rubber) in bituminous construction and as a crack sealer. Crumb rubber asphalt concrete (CR-AC) leachates contain a mixture of organic and metallic contaminants. Benzothiazole and 2(3H)-benzothiazolone (organic compounds used in tire rubber manufacturing) and the metals mercury and aluminum were leached in potentially harmful concentrations (exceeding toxic concentrations for aquatic toxicity tests). CR-AC leachate exhibited moderate to high toxicity for algae ( Selenastrum capriconutum) and moderate toxicity for water fleas ( Daphnia magna). Benzothiazole was readily removed from CR-AC leachate by the environmental processes of soil sorption, volatilization, and biodegradation. Metals, which do not volatilize or photochemically or biologically degrade, were removed from the leachate by soil sorption. Contaminants from CR-AC leachates are thus degraded or retarded in their transport through nearby soils and ground waters.

  12. INVESTIGATION OF PROCESS PERTAINING TO INTERACTION OF TRACTOR DRIVING WHEELS WITH GROUND SURFACE

    Directory of Open Access Journals (Sweden)

    V. V. Guskov

    2017-01-01

    Full Text Available The paper presents results of investigations on the process pertaining to interaction of a driving wheel with ground surface and describes methodology for optimization of backbone parameters. The mentioned process has some specific differences in comparison with the process of wheel rolling along hard surface. Ground surface is represented by mixture of sandy and clay particles with plant residues and it has a number of physical and mechanical properties. The main of these properties is resistance of soil against compression and displacement. Compression process determines a track depth and resistance to motion and displacement process determines wheel gripping property and its tangential traction force. While executing the investigations laws of compression and displacement proposed by Prof.V. V. Katsygin as the most adequate reflection of actual processes have been used in the paper. Motion of the driving wheel along ground surface is accompanied by its slipping. It has been determined that the maximum wheel traction force is formed not with 100% slipping as it was supposed until present but the value has been obtained at 45–60 % slipping according to soil category. The developed integral equations with due account of the aspect make it possible to calculate road hold characteristics of driving wheels of the designed wheel tractor and evaluate its traction, speed and economic characteristics. Methodology has been developed for optimization of backbone parameters of wheeled running gear in the designed tractor such as design mass and adhesion weight, width, diameter and air pressure in a tire. The proposed methodology has been introduced in designing practice of wheeled tractors at OJSC “Minsk Tractor Works”.

  13. The dispersed fluorescence spectrum of NaAr - Ground and excited state potential curves

    Science.gov (United States)

    Tellinghuisen, J.; Ragone, A.; Kim, M. S.; Auerbach, D. J.; Smalley, R. E.; Wharton, L.; Levy, D. H.

    1979-01-01

    Potential curves for the ground state and the first excited state of NaAr were determined. The van der Waals molecule NaAr was prepared by supersonic free jet expansion of a mixture of sodium, argon, and helium. The electronic transition from the ground state to the first excited state A2pi was excited by a tunable dye laser and the resulting fluorescence was studied. The dispersed fluorescence spectra show discrete and diffuse features, corresponding to transitions from excited vibrational levels of the A state to bound and unbound levels of the x state. The characteristic reflection structure in the bound-free spectra permits an unambiguous assignment of the vibrational numbering in the A state, and this assignment together with previously measured spectroscopic constants are used to calculate the potential curve of the A state. The discrete structure in the fluorescence spectra is used to determine the potential curve of the x state in the well region, and the repulsive part of the X curve is then deduced through trial-and-error simulation of the bound-free spectra.

  14. Ground-water flow and the potential effects of remediation at Graces Quarters, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Tenbus, F.J.; Fleck, W.B.

    1996-01-01

    Ground water in the east-central part of Graces Quarters, a former open-air chemical-agent test facility at Aberdeen Proving Ground, Maryland, is contaminated with chlorinated volatile organic compounds. The U.S. Geological Survey's finite- difference model was used to help understand ground-water flow and simulate the effects of alternative remedial actions to clean up the ground water. Scenarios to simulate unstressed conditions and three extraction well con- figurations were used to compare alternative remedial actions on the contaminant plume. The scenarios indicate that contaminants could migrate from their present location to wetland areas within 10 years under unstressed conditions. Pumping 7 gal/min (gallons per minute) from one well upgradient of the plume will not result in containment or removal of the highest contaminant concentrations. Pumping 7 gal/min from three wells along the central axis of the plume should result in containment and removal of dissolved contami- nants, as should pumping 7 gal/min from three wells at the leading edge of the plume while injecting 7 gal/min back into an upgradient well.

  15. Connection for transfer of Liquid Nitrogen from High Voltage to ground potential

    DEFF Research Database (Denmark)

    Rasmussen, Claus Nygaard; Hansen, Finn; Willén, Dag

    2001-01-01

    In order to operate a superconducting cable conductor it must be kept at a cryogenic temperature (e.g. using liquid nitrogen). The superconducting cable conductor is at high voltage and the cooling equipment is kept at ground potential. This requires a thermally insulating connection that is also...... strength. However, samples of ExpancelÒ (polymer foam) have recently proved to withstand large electrical fields at room temperature as well as at cryogenic temperatures. In this work, two prototype devices have been tested with respect to the partial discharge inception voltage, thermal insulation...

  16. Advanced ground-based gravitational-wave detectors' potential to detect generic deviations from general relativity

    CERN Document Server

    Narikawa, Tatsuya

    2016-01-01

    We discuss the potential of the advanced ground-based gravitational-wave detectors, such as LIGO, Virgo, and KAGRA, to detect generic deviations of gravitational waveforms from the prediction of General Relativity. We use the parameterized post-Einsteinian formalism to characterize the deviations, and assess how much magnitude of the deviations are detectable by using an approximate decision scheme based on Bayesian statistics. We find that there exist detectable regions of the parameterized post-Einsteinian parameters by using a single gravitational wave event. The regions are not excluded by currently existing binary pulsar observations for the parameterized post-Einsteinian parameters at higher post-Newtonian order.

  17. Spectrally selective surfaces for ground and space-based instrumentation: support for a resource base

    Science.gov (United States)

    McCall, Susan H.; Sinclair, R. Lawrence; Pompea, Stephen M.; Breault, Robert P.

    1993-11-01

    The performance of space telescopes, space instruments, and space radiator systems depends critically upon the selection of appropriate spectrally selective surfaces. Many space programs have suffered severe performance limitations, schedule setbacks, and spent hundreds of thousands of dollars in damage control because of a lack of readily-accessible, accurate data on the properties of spectrally selective surfaces, particularly black surfaces. A Canadian effort is underway to develop a resource base (database and support service) to help alleviate this problem. The assistance of the community is required to make the resource base comprehensive and useful to the end users. The paper aims to describe the objectives of this project. In addition, a request for information and support is made for various aspects of the project. The resource base will be useful for both ground and space-based instrumentation.

  18. Electrophysiological potentials reveal cortical mechanisms for mental imagery, mental simulation, and grounded (embodied cognition

    Directory of Open Access Journals (Sweden)

    Haline E. Schendan

    2012-09-01

    Full Text Available Grounded cognition theory proposes that cognition, including meaning, is grounded in sensorimotor processing. The mechanism for grounding cognition is mental simulation, which is a type of mental imagery that re-enacts modal processing. To reveal top-down, cortical mechanisms for mental simulation of shape, event-related potentials were recorded to face and object pictures preceded by mental imagery of a picture. Mental imagery of the identical face or object (congruous condition facilitated not only categorical perception (VPP/N170 but also later visual knowledge (N3[00] complex and linguistic knowledge (N400 for faces more than objects, and strategic semantic analysis (late positive complex between 200 and 700 ms. The later effects resembled semantic congruity effects with pictures. Mental imagery also facilitated category decisions, as a P3(00 peaked earlier for congruous than incongruous (other category pictures, resembling the case when identical pictures repeat immediately. Thus mental imagery mimics semantic congruity and immediate repetition priming processes with pictures. Perception control results showed the opposite for faces and were in the same direction for objects: Perceptual repetition adapts (and so impairs processing of perceived faces from categorical perception onwards, but primes processing of objects during categorical perception, visual knowledge processes, and strategic semantic analysis. For both imagery and perception, differences between faces and objects support domain-specificity and indicate that cognition is grounded in modal processing. Altogether, this direct neural evidence reveals that top-down processes of mental imagery sustain an imagistic representation that mimics perception well enough to prime subsequent perception and cognition. This also suggests that automatic mental simulation of the visual shape of faces and objects operates between 200 and 400 ms, and strategic mental simulation operates between

  19. Conceptual Tenets of the Theory of Hydration of Heterogeneous Surface with Polar Order of Disperse Ground Layers of Sedimentary Genesis

    Directory of Open Access Journals (Sweden)

    Tamara G. Makeeva

    2012-09-01

    Full Text Available The article, basing on the established regularity defines the basic tenets of the theory of hydration of heterogeneous surface with polar order of disperse ground layers of sedimentary genesis. It offers classification and formula for the associated water density, valid corrections for the associated water density, calculates the water film thickness in disperse ground, develops the reliable physicochemical model of the disperse ground, determines the range of applicability of the existing laboratory and field methods.

  20. Osteogenic potential of laser modified and conditioned titanium zirconium surfaces

    Directory of Open Access Journals (Sweden)

    P David Charles

    2016-01-01

    Full Text Available Statement of Problem: The osseointegration of dental implant is related to their composition and surface treatment. Titanium zirconium (TiZr has been introduced as an alternative to the commercially pure titanium and its alloys as dental implant material, which is attributed to its superior mechanical and biological properties. Surface treatments of TiZr have been introduced to enhance their osseointegration ability; however, reliable, easy to use surface modification technique has not been established. Purpose: The purpose of this study was to evaluate and compare the effect of neodymium-doped yttrium aluminum garnet (Nd-YAG laser surface treatment of TiZr implant alloy on their osteogenic potential. Materials and Methods: Twenty disc-shaped samples of 5 mm diameter and 2 mm height were milled from the TiZr alloy ingot. The polished discs were ultrasonically cleaned in distilled water. Ten samples each were randomly selected as Group A control samples and Group B consisted of Nd-YAG laser surface etched and conditioned test samples. These were evaluated for cellular response. Cellular adhesion and proliferation were quantified, and the results were statistically analyzed using nonparametric analysis. Cellular morphology was observed using electron and epiflurosence microscopy. Results: Nd-YAG laser surface modified and conditioned TiZr samples increased the osteogenic potential. Conclusion: Nd-YAG laser surface modification of TiZr, improves the cellular activity, surface roughness, and wettability, thereby increasing the osteogenic potential.

  1. In search of a broader microscopic underpinning of the potential energy surface in heavy deformed nuclei

    Science.gov (United States)

    Hess, P. O.; Ermamatov, M.

    2017-07-01

    Starting from the content of the shell model space and using a simple symplectic as a weight Hamiltonian, the relative positions of different symplectic irreducible representations are deduced. Applying a geometrical mapping leads to a microscopically derived Potential-Energy-Surface. After smoothing this surface and fitting a mass parameter to the first excited 6+-state in the ground state band, the spectrum of a nucleus can be reproduced qualitatively. The method is also used to obtain a first estimation of the quadrupole Potential Energy Surface of any nucleus, allowing to obtain information about the structure of the nucleus in question. Of special interest is the prediction of the structure of nuclei away from the valley of stability and of super-heavy nuclei. The method will be illustrated at184W. One objective is to show that the Pauli Exclusion Principle is the main driving force for the structure of a nucleus, though some further microscopic input has to be used.

  2. Ab initio potential energy and dipole moment surfaces of the F(-)(H2O) complex.

    Science.gov (United States)

    Kamarchik, Eugene; Toffoli, Daniele; Christiansen, Ove; Bowman, Joel M

    2014-02-05

    We present full-dimensional, ab initio potential energy and dipole moment surfaces for the F(-)(H2O) complex. The potential surface is a permutationally invariant fit to 16,114 coupled-cluster single double (triple)/aVTZ energies, while the dipole surface is a covariant fit to 11,395 CCSD(T)/aVTZ dipole moments. Vibrational self-consistent field/vibrational configuration interaction (VSCF/VCI) calculations of energies and the IR-spectrum are presented both for F(-)(H2O) and for the deuterated analog, F(-)(D2O). A one-dimensional calculation of the splitting of the ground state, due to equivalent double-well global minima, is also reported.

  3. Use of ground-water reservoirs for storage of surface water in the San Joaquin Valley, California

    Science.gov (United States)

    Davis, G.H.; Lofgren, B.E.; Mack, Seymour

    1964-01-01

    occurs in alluvial and lacustrine deposits of late Pliocene age or older; and 3) a body of saline connate water contained in marine sediments of middle Pliocene or older age, which underlies the fresh-water body throughout the area. In much of the eastern part of the valley, especially in the areas of the major streams, the Corcoran clay member is not present and ground water occurs as one fresh-water body to considerable depth. The ground-water body is replenished by infiltration of rainfall, by infiltration from streams, canals, and ditches, by underflow entering the valley from tributary stream canyons, and by infiltration of excess irrigation water. In much of the valley, however, the annual rainfall is so low that little penetrates deeply, and soil-moisture deficiency is perennial. Infiltration from stream channels and canals and from irrigated fields are the principal sources of groundwater recharge. The ground-water storage capacity of the San Joaquin Valley has been estimated in an earlier report (Davis and others, 1959) as 93 million acre-feet. This is the quantity of water that would drain by gravity from the valley deposits if the regional water level were lowered from 10 to 200 feet below the land surface. Storage capacity was estimated for only the part of the valley considered to be potentially usable as a ground-water reservoir. In this study, a 200foot depth was selected as a practical valley-wide depth limit for unwatering under full utilization of the ground-water reservoir, even though in localized areas sections in excess of 350 feet in depth have already been dewatered. Some of the factors that locally limit the utilization of the ground-water reservoir are inferior water quality, relatively impermeable surface soils, and relatively impermeable subsurface deposits. On the basis of a detailed analysis of la peg model, the subsurface geology of the San Joaquin Valley was subdivided into predominantly permeable and impermeable zones in the 1

  4. Ground-state potential energy curves of LiHg, NaHg, and KHg revisited

    Science.gov (United States)

    Thiel, Linda; Hotop, Hartmut; Meyer, Wilfried

    2003-11-01

    We present the results of large-scale CCSD(T) calculations on the potential energy curves for the ground states of LiHg, NaHg, and KHg. In these calculations, the Hg20+ core is simulated by a pseudopotential which has been adjusted to reproduce experimental excitation and ionization energies of the Hg atom at the coupled-cluster level. Moreover, we apply a weighted multiproperty fitting procedure to determine reliable potentials for LiHg, NaHg, and KHg which reproduce the available experimental results. In the case of LiHg, this best-fit potential is based solely on experimental data and its agreement with our calculated potential supports our computational procedure. For NaHg and KHg the experimental data had to be complemented by theoretical results in order to fix a best-fit potential. Our potentials and those proposed previously are evaluated by comparing calculated scattering cross sections and vibrational energy levels with the available experimental data.

  5. Assessment of nitrification potential in ground water using short term, single-well injection experiments.

    Science.gov (United States)

    Smith, R L; Baumgartner, L K; Miller, D N; Repert, D A; Böhlke, J K

    2006-01-01

    Nitrification was measured within a sand and gravel aquifer on Cape Cod, MA, using a series of single-well injection tests. The aquifer contained a wastewater-derived contaminant plume, the core of which was anoxic and contained ammonium. The study was conducted near the downgradient end of the ammonium zone, which was characterized by inversely trending vertical gradients of oxygen (270 to 0 microM) and ammonium (19 to 625 microM) and appeared to be a potentially active zone for nitrification. The tests were conducted by injecting a tracer solution (ambient ground water + added constituents) into selected locations within the gradients using multilevel samplers. After injection, the tracers moved by natural ground water flow and were sampled with time from the injection port. Rates of nitrification were determined from changes in nitrate and nitrite concentration relative to bromide. Initial tests were conducted with (15)N-enriched ammonium; subsequent tests examined the effect of adding ammonium, nitrite, or oxygen above background concentrations and of adding difluoromethane, a nitrification inhibitor. In situ net nitrate production exceeded net nitrite production by 3- to 6- fold and production rates of both decreased in the presence of difluoromethane. Nitrification rates were 0.02-0.28 mumol (L aquifer)(-1) h(-1) with in situ oxygen concentrations and up to 0.81 mumol (L aquifer)(-1) h(-1) with non-limiting substrate concentrations. Geochemical considerations indicate that the rates derived from single-well injection tests yielded overestimates of in situ rates, possibly because the injections promoted small-scale mixing within a transport-limited reaction zone. Nonetheless, these tests were useful for characterizing ground water nitrification in situ and for comparing potential rates of activity when the tracer cloud included non-limiting ammonium and oxygen concentrations.

  6. On the submarine communication cable JASC ground self-potential stability

    Science.gov (United States)

    Starjinsky, S. S.; Nikiforov, V. M.

    2005-09-01

    This investigation was undertaken for searching the source of linear trends in JASC submarine cable data over the time interval of 6 years and estimating the electrode noise level. One of the reasons for a trend is probably the potential instability in the cable ground, which happened because the titanium electrodes of the ground were placed in sea water that is electrochemically active. To study this phenomenon, we have registered the voltage variations of three titanium JASC cable electrodes, which were closely spaced (~15 cm) and placed at a depth of ~15 m near the coast for 70 days, synchronously with JASC cable voltage observations. The electrode noise level and coherence between channels were estimated and linear trends in electrode pair voltage variation were revealed. The estimated linear trend magnitude is about 0.28 mV/day, which is comparable with 0.21 mV/day earlier observed in JASC submarine cable data. We concluded that the linear trend in JASC cable data is, at least partly, probably caused by the titanium electrodes potential variations. This linear trend should be registered simultaneously with JASC cable voltage observation, keeping in mind the possibility of finding a procedure for removing it, in order to enhance the signal/noise ratio in data.

  7. Crevice Repassivation Potentials for Alloy 22 in Simulated Concentrated Ground Waters

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, R B; Evans, K J; Ilevbare, G O

    2006-11-08

    The resistance of Alloy 22 (N06022) to localized corrosion, mainly crevice corrosion, has been extensively investigated in the last few years. However, the behavior of Alloy 22 in concentrated aqueous solutions that may simulate concentrated ground waters was not fully understood. Systematic electrochemical tests using cyclic potentiodynamic polarization as well as the Tsujikawa-Hisamatsu electrochemical method were performed to determine the crevice corrosion susceptibility of Alloy 22 in simulated concentrated water (SCW), simulated acidified water (SAW) and basic saturated water (BSW). Results show that Alloy 22 is immune to crevice corrosion in SCW and SAW but may suffer crevice corrosion initiation in BSW. Results also show that in a naturally aerated environment, the corrosion potential would never reach the critical potential for crevice corrosion initiation.

  8. Mapping of permafrost surface using ground-penetrating radar at Kangerlussuaq Airport, western Greenland

    DEFF Research Database (Denmark)

    Jørgensen, Anders Stuhr; Andreasen, Frank

    2007-01-01

    Kangerlussuaq Airport is located at 67°N and 51°W in the zone of continuous permafrost in western Greenland. Its proximity to the Greenlandic ice sheet results in a dry sub-arctic climate with a mean annual temperature of −5.7 °C. The airport is built on a river terrace mostly consisting of fluvial...... deposits overlying fine-grained marine melt-water sediments and bedrock. A ground-penetrating radar (GPR) survey was performed to study the frozen surface beneath the airfield. The measurements were carried out in late July 2005 on the southern parking area in Kangerlussuaq Airport. Five years earlier...

  9. Asymmetric Rock Pressure on Shallow Tunnel in Strata with Inclined Ground Surface

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xiao-jun; YANG Chang-yu

    2007-01-01

    By building a tunnel model with a semi-circular crown, the asymmetric rock pressure applied to the shallow tunnel in strata with inclined ground surface is analyzed. Formulae, which not only include the parameters related to both tunnel structure and surrounding rock mass, but the overburden depth, are developed. The computation for four tunnel models show that the method presented is feasible and convenient. Furthermore, the influence of the overburden depth on the rock pressure is elaborated, and the criterion to identify the deep or shallow tunnels is formulated as well.

  10. An ab initio potential energy surface and vibrational energy levels of HXeBr

    Institute of Scientific and Technical Information of China (English)

    Zheng Guo Huang; En Cui Yang; Dai Qian Xie

    2008-01-01

    A three-dimensional global potential energy surface for the electronic ground state of HXeBr molecule is constructed from morethan 4200 ab initio points. These points are generated using an internally contracted multi-reference configuration interactionmethod with the Davidson correction (icMRCI + Q) and large basis sets. The stabilities and dissociation barriers are identified fromthe potential energy surfaces. The three-body dissociation channel is found to be the dominate dissociation channel for HXeBr.Based on the obtained potentials, low-lying vibrational energy levels of HXeBr calculated using the Lanczos algorithm is found tobe in good agreement with the available experimental band origins.2008 Zheng Guo Huang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

  11. A "First Principles" Potential Energy Surface for Liquid Water from VRT Spectroscopy of Water Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, N; Leforestier, C; Saykally, R J

    2004-05-25

    We present results of gas phase cluster and liquid water simulations from the recently determined VRT(ASP-W)III water dimer potential energy surface. VRT(ASP-W)III is shown to not only be a model of high ''spectroscopic'' accuracy for the water dimer, but also makes accurate predictions of vibrational ground-state properties for clusters up through the hexamer. Results of ambient liquid water simulations from VRT(ASP-W)III are compared to those from ab initio Molecular Dynamics, other potentials of ''spectroscopic'' accuracy, and to experiment. The results herein represent the first time that a ''spectroscopic'' potential surface is able to correctly model condensed phase properties of water.

  12. Potential energy surface of the photolysis of isocyanic acid HNCO

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The dissociation curves of the photolysis of the isocyanic acidHNCOHN+CO corresponding to the ground state (S0), the first triplet excited state (T1) and the first singlet excited state (S1) have been studied respectively at the UHF/6-311G** and CIS/6-311G** levels using ab initio method. The energy surface crossing points, S1/T1, T1/S0 and S1/S0, have been found and the characteristics of the energy minimum crossing point were given, based on which, the changes of the crossing points' geometries along the lower electronic energy surface and its end-result have been located according to the steepest descent principle. The computational result indicates that the photolysis of the isocyanic acid HNCOHN+CO has three competitive reaction channels ((A)-(C)), and from the kinetic piont of view, channel (A) is the most advantageous.

  13. Surface Signature Characterization at SPE through Ground-Proximal Methods: Methodology Change and Technical Justification

    Energy Technology Data Exchange (ETDEWEB)

    Schultz-Fellenz, Emily S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-09

    A portion of LANL’s FY15 SPE objectives includes initial ground-based or ground-proximal investigations at the SPE Phase 2 site. The area of interest is the U2ez location in Yucca Flat. This collection serves as a baseline for discrimination of surface features and acquisition of topographic signatures prior to any development or pre-shot activities associated with SPE Phase 2. Our team originally intended to perform our field investigations using previously vetted ground-based (GB) LIDAR methodologies. However, the extended proposed time frame of the GB LIDAR data collection, and associated data processing time and delivery date, were unacceptable. After technical consultation and careful literature research, LANL identified an alternative methodology to achieve our technical objectives and fully support critical model parameterization. Very-low-altitude unmanned aerial systems (UAS) photogrammetry appeared to satisfy our objectives in lieu of GB LIDAR. The SPE Phase 2 baseline collection was used as a test of this UAS photogrammetric methodology.

  14. Surface geophysical methods for characterising frozen ground in transitional permafrost landscapes

    Science.gov (United States)

    Briggs, Martin; Campbell, Seth; Nolan, Jay; Walvoord, Michelle Ann; Ntarlagiannis, Dimitrios; Day-Lewis, Frederick D.; Lane, John

    2017-01-01

    The distribution of shallow frozen ground is paramount to research in cold regions, and is subject to temporal and spatial changes influenced by climate, landscape disturbance and ecosystem succession. Remote sensing from airborne and satellite platforms is increasing our understanding of landscape-scale permafrost distribution, but typically lacks the resolution to characterise finer-scale processes and phenomena, which are better captured by integrated surface geophysical methods. Here, we demonstrate the use of electrical resistivity imaging (ERI), electromagnetic induction (EMI), ground penetrating radar (GPR) and infrared imaging over multiple summer field seasons around the highly dynamic Twelvemile Lake, Yukon Flats, central Alaska, USA. Twelvemile Lake has generally receded in the past 30 yr, allowing permafrost aggradation in the receded margins, resulting in a mosaic of transient frozen ground adjacent to thick, older permafrost outside the original lakebed. ERI and EMI best evaluated the thickness of shallow, thin permafrost aggradation, which was not clear from frost probing or GPR surveys. GPR most precisely estimated the depth of the active layer, which forward electrical resistivity modelling indicated to be a difficult target for electrical methods, but could be more tractable in time-lapse mode. Infrared imaging of freshly dug soil pit walls captured active-layer thermal gradients at unprecedented resolution, which may be useful in calibrating emerging numerical models. GPR and EMI were able to cover landscape scales (several kilometres) efficiently, and new analysis software showcased here yields calibrated EMI data that reveal the complicated distribution of shallow permafrost in a transitional landscape.

  15. Quality of surface and ground waters, Yakima Indian Reservation, Washington, 1973-74

    Science.gov (United States)

    Fretwell, M.O.

    1977-01-01

    This report describes the quality of the surface and ground waters of the Yakima Indian Reservation in south-central Washington, during the period November 1973-October 1974. The average dissolved-solids concentrations ranged from 48 to 116 mg/L (milligrams per liter) in the mountain streams, and from 88 to 372 mg/L in the lowland streams, drains, and a canal. All the mountain streams contain soft water (classified as 0-60 mg/L hardness as CaC03), and the lowland streams, drains, and canal contain soft to very hard water (more than 180 mg/L hardness as CaC03). The water is generally of suitable quality for irrigation, and neither salinity nor sodium hazards are a problem in waters from any of the streams studied. The specific conductance of water from the major aquifers ranged from 20 to 1 ,540 micromhos. Ground water was most dilute in mineral content in the Klickitat River basin and most concentrated in part of the Satus Creek basin. The ground water in the Satus Creek basin with the most concentrated mineral content also contained the highest percentage composition of sulfate, chloride, and nitrate. For drinking water, the nitrate-nitrogen concentrations exceeded the U.S. Public Health Service 's recommended limit of 10 mg/L over an area of several square miles, with a maximum observed concentration of 170 mg/L. (Woodard-USGS).

  16. Mechanism and bounding of earthquake energy input to building structure on surface ground subjected to engineering bedrock motion

    OpenAIRE

    Kojima, K; Sakaguchi, K; Takewaki, I.

    2015-01-01

    The mechanism of earthquake energy input to building structures is clarified by considering the surface ground amplification and soil–structure interaction. The earthquake input energies to superstructures, soil–foundation systems and total swaying–rocking system are obtained by taking the corresponding appropriate free bodies into account and defining the energy transfer functions. It has been made clear that, when the ground surface motion is white, the input energy to the swaying–rocking m...

  17. Evaluating the potential of IASI ozone observations to constrain simulated surface ozone concentrations

    Directory of Open Access Journals (Sweden)

    M. Beekmann

    2009-11-01

    Full Text Available A tracer study has been performed for two summers in 2003 and 2004 with a regional chemistry-transport model in order to evaluate the potential constraint that tropospheric ozone observations from nadir viewing infrared sounders like IASI or TES exert on modelled near surface ozone. As these instruments show high sensitivity in the free troposphere, but low sensitivity at ground, it is important to know how much of the information gained in the free troposphere is transferred to ground through vertical transport processes. Within the European model domain, and within a time span of 4 days, only ozone like tracers initialised in vertical layers above 500 hPa are transported to the surface. For a tracer initialised between 800 and 700 hPa, seven percent reaches the surface within one to three days, on the average over the European model domain but more than double over the Mediterranean Sea. For this region, trajectory analysis shows that this is related to strong subsident transport. These results are confirmed by a second tracer study taking into account averaging kernels related to IASI retrievals, indicating the potential of these measurements to efficiently constrain surface ozone values.

  18. SURFACE GEOPHYSICAL EXPLORATION OF TX-TY TANK FARMS AT THE HANFORD SITE RESULTS OF BACKGROUND CHARACTERIZATION WITH GROUND PENETRATING RADAR

    Energy Technology Data Exchange (ETDEWEB)

    MYERS DA; CUBBAGE R; BRAUCHLA R; O' BRIEN G

    2008-07-24

    Ground penetrating radar surveys of the TX and TY tank farms were performed to identify existing infrastructure in the near surface environment. These surveys were designed to provide background information supporting Surface-to-Surface and Well-to-Well resistivity surveys of Waste Management Area TX-TY. The objective of the preliminary investigation was to collect background characterization information with GPR to understand the spatial distribution of metallic objects that could potentially interfere with the results from high resolution resistivity{trademark} surveys. The results of the background characterization confirm the existence of documented infrastructure, as well as highlight locations of possible additional undocumented subsurface metallic objects.

  19. Realization of Multi-Stable Ground States in a Nematic Liquid Crystal by Surface and Electric Field Modification

    Science.gov (United States)

    Gwag, Jin Seog; Kim, Young-Ki; Lee, Chang Hoon; Kim, Jae-Hoon

    2015-06-01

    Owing to the significant price drop of liquid crystal displays (LCDs) and the efforts to save natural resources, LCDs are even replacing paper to display static images such as price tags and advertising boards. Because of a growing market demand on such devices, the LCD that can be of numerous surface alignments of directors as its ground state, the so-called multi-stable LCD, comes into the limelight due to the great potential for low power consumption. However, the multi-stable LCD with industrial feasibility has not yet been successfully performed. In this paper, we propose a simple and novel configuration for the multi-stable LCD. We demonstrate experimentally and theoretically that a battery of stable surface alignments can be achieved by the field-induced surface dragging effect on an aligning layer with a weak surface anchoring. The simplicity and stability of the proposed system suggest that it is suitable for the multi-stable LCDs to display static images with low power consumption and thus opens applications in various fields.

  20. Electrical mapping of microtubular structures by surface potential microscopy

    Science.gov (United States)

    Zhang, Peng; Cantiello, Horacio F.

    2009-09-01

    Microtubules (MTs) are important cytoskeletal polymers that play an essential role in cell division and transport in all eukaryotes and information processing in neurons. MTs are highly charged polyelectrolytes, composed of hollow cylindrical arrangements of αβ-tubulin dimers. To date, there is little information about electrical properties of MTs. Here, we deposited and dried MTs onto a gold-plated surface to image their topology by atomic force microscopy (AFM), and determined their electrical mapping with surface potential microscopy (SPM). We found a strong linear correlation between the magnitude of relative surface potential and MT parameters, including diameter and height. AFM images confirmed the cylindrical topology of microtubular structures, and the presence of topological discontinuities along their surface, which may contribute to their unique electrical properties.

  1. Modeling surface and ground water mixing in the hyporheic zone using MODFLOW and MT3D

    Science.gov (United States)

    Lautz, Laura K.; Siegel, Donald I.

    2006-11-01

    We used a three-dimensional MODFLOW model, paired with MT3D, to simulate hyporheic zones around debris dams and meanders along a semi-arid stream. MT3D simulates both advective transport and sink/source mixing of solutes, in contrast to particle tracking (e.g. MODPATH), which only considers advection. We delineated the hydrochemically active hyporheic zone based on a new definition, specifically as near-stream subsurface zones receiving a minimum of 10% surface water within a 10-day travel time. Modeling results indicate that movement of surface water into the hyporheic zone is predominantly an advective process. We show that debris dams are a key driver of surface water into the subsurface along the experimental reach, causing the largest flux rates of water across the streambed and creating hyporheic zones with up to twice the cross-sectional area of other hyporheic zones. Hyporheic exchange was also found in highly sinuous segments of the experimental reach, but flux rates are lower and the cross-sectional areas of these zones are generally smaller. Our modeling approach simulated surface and ground water mixing in the hyporheic zone, and thus provides numerical approximations that are more comparable to field-based observations of surface-groundwater exchange than standard particle-tracking simulations.

  2. Modelling the Influence of Ground Surface Relief on Electric Sounding Curves Using the Integral Equations Method

    Directory of Open Access Journals (Sweden)

    Balgaisha Mukanova

    2017-01-01

    Full Text Available The problem of electrical sounding of a medium with ground surface relief is modelled using the integral equations method. This numerical method is based on the triangulation of the computational domain, which is adapted to the shape of the relief and the measuring line. The numerical algorithm is tested by comparing the results with the known solution for horizontally layered media with two layers. Calculations are also performed to verify the fulfilment of the “reciprocity principle” for the 4-electrode installations in our numerical model. Simulations are then performed for a two-layered medium with a surface relief. The quantitative influences of the relief, the resistivity ratios of the contacting media, and the depth of the second layer on the apparent resistivity curves are established.

  3. An adaptive interpolation scheme for molecular potential energy surfaces

    Science.gov (United States)

    Kowalewski, Markus; Larsson, Elisabeth; Heryudono, Alfa

    2016-08-01

    The calculation of potential energy surfaces for quantum dynamics can be a time consuming task—especially when a high level of theory for the electronic structure calculation is required. We propose an adaptive interpolation algorithm based on polyharmonic splines combined with a partition of unity approach. The adaptive node refinement allows to greatly reduce the number of sample points by employing a local error estimate. The algorithm and its scaling behavior are evaluated for a model function in 2, 3, and 4 dimensions. The developed algorithm allows for a more rapid and reliable interpolation of a potential energy surface within a given accuracy compared to the non-adaptive version.

  4. An adaptive interpolation scheme for molecular potential energy surfaces

    CERN Document Server

    Kowalewski, Markus; Heryudono, Alfa

    2016-01-01

    The calculation of potential energy surfaces for quantum dynamics can be a time consuming task -- especially when a high level of theory for the electronic structure calculation is required. We propose an adaptive interpolation algorithm based on polyharmonic splines combined with a partition of unity approach. The adaptive node refinement allows to greatly reduce the number of sample points by employing a local error estimate. The algorithm and its scaling behavior is evaluated for a model function in 2, 3 and 4 dimensions. The developed algorithm allows for a more rapid and reliable interpolation of a potential energy surface within a given accuracy compared to the non-adaptive version.

  5. Surface potential domains on lamellar P3OT structures

    Energy Technology Data Exchange (ETDEWEB)

    Perez-GarcIa, B [Departamento Fisica, Facultad de Quimica (Campus Espinardo), Universidad de Murcia, E-30100 Murcia (Spain); Abad, J [Departamento Fisica, Facultad de Quimica (Campus Espinardo), Universidad de Murcia, E-30100 Murcia (Spain); Urbina, A [Departamento Electronica, TecnologIa de Computadoras y Proyectos, Universidad Politecnica de Cartagena, E-30202 Cartagena (Spain); Colchero, J [Departamento Fisica, Facultad de Quimica (Campus Espinardo), Universidad de Murcia, E-30100 Murcia (Spain); Palacios-Lidon, E [Departamento Fisica, Facultad de Quimica (Campus Espinardo), Universidad de Murcia, E-30100 Murcia (Spain)

    2008-02-13

    In this work the electrostatic properties of poly(3-octylthiophene) thin films have been studied on a nanometer scale by means of electrostatic force microscopy and Kelvin probe microscopy (KPM). The KPM images reveal that different surface contact potential domains coexist on the polymer surface. This result, together with additional capacitance measurements, indicates that the potential domains are related to the existence of dipoles due to different molecular arrangements. Finally, capacitance measurements as a function of the tip-sample bias voltage show that in all regions large band bending effects take place.

  6. Flux of benzo(a)pyrene to the ground surface and its distribution in the ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Milukaite, A. [Institute of Physics, Vilnius (Lithuania)

    1998-07-01

    Benzo(a)pyrene (BP) has been investigated in bulk atmospheric deposition, moss, needles of pine and some species of vascular plants. At two remote Lithuanian sites, for 1990-1995 the flux of benzo(a)pyrene from the atmosphere to the ground surface varied between 0.3 to 4.8 {mu}g{sup -2} mo{sup -1}. Consequently the territory of Lithuania (65,000 km{sup 2}) yearly was exposed to 624-2574 kg of carcinogen. The distribution of BP in soil and various vascular plant tissues (trifolium tepens, Elitrygea repens, Thymus serpyllum) indicates that benzo(a)pyrene is assimilated by flora. The concentration of BP is different in various organs of vascular plants and mostly depends on the degree of soil pollution. More than 300 samples of moss, mostly Hylocomium spendens and Pleurozium schreberi were analysed for BP. From 3.1 to 896.0 {mu}g kg{sup -1} of BP were measured in the moss samples. The flux of BP to the ground surface correlates well with its concentration in moss. A map of BP flux across Lithuania was created. 20 refs., 3 figs., 3 tabs.

  7. Human health impacts of drinking water (surface and ground) pollution Dakahlyia Governorate, Egypt

    Science.gov (United States)

    Mandour, R. A.

    2012-09-01

    This study was done on 30 drinking tap water samples (surface and ground) and 30 urine samples taken from patients who attended some of Dakahlyia governorate hospitals. These patients were complaining of poor-quality tap water in their houses, which was confirmed by this study that drinking water is contaminated with trace elements in some of the studied areas. The aim of this study was to determine the relationship between the contaminant drinking water (surface and ground) in Dakahlyia governorate and its impact on human health. This study reports the relationship between nickel and hair loss, obviously shown in water and urine samples. Renal failure cases were related to lead and cadmium contaminated drinking water, where compatibilities in results of water and urine samples were observed. Also, liver cirrhosis cases were related to iron-contaminated drinking water. Studies of these diseases suggest that abnormal incidence in specific areas is related to industrial wastes and agricultural activities that have released hazardous and toxic materials in the drinking water and thereby led to its contamination in these areas. We conclude that trace elements should be removed from drinking water for human safety.

  8. Analysis of selected herbicide metabolites in surface and ground water of the United States

    Science.gov (United States)

    Scribner, E.A.; Thurman, E.M.; Zimmerman, L.R.

    2000-01-01

    One of the primary goals of the US Geological Survey (USGS) Laboratory in Lawrence, Kansas, is to develop analytical methods for the analysis of herbicide metabolites in surface and ground water that are vital to the study of herbicide fate and degradation pathways in the environment. Methods to measure metabolite concentrations from three major classes of herbicides - triazine, chloroacetanilide and phenyl-urea - have been developed. Methods for triazine metabolite detection cover nine compounds: six compounds are detected by gas chromatography/mass spectrometry; one is detected by high-performance liquid chromatography with diode-array detection; and eight are detected by liquid chromatography/mass spectrometry. Two metabolites of the chloroacetanilide herbicides - ethane sulfonic acid and oxanilic acid - are detected by high-performance liquid chromatography with diode-array detection and liquid chromatography/mass spectrometry. Alachlor ethane sulfonic acid also has been detected by solid-phase extraction and enzyme-linked immunosorbent assay. Six phenylurea metabolites are all detected by liquid chromatography/mass spectrometry; four of the six metabolites also are detected by gas chromatography/mass spectrometry. Additionally, surveys of herbicides and their metabolites in surface water, ground water, lakes, reservoirs, and rainfall have been conducted through the USGS laboratory in Lawrence. These surveys have been useful in determining herbicide and metabolite occurrence and temporal distribution and have shown that metabolites may be useful in evaluation of non-point-source contamination. Copyright (C) 2000 Elsevier Science B.V.

  9. Sliding surface searching method for slopes containing a potential weak structural surface

    Directory of Open Access Journals (Sweden)

    Aijun Yao

    2014-06-01

    Full Text Available Weak structural surface is one of the key factors controlling the stability of slopes. The stability of rock slopes is in general concerned with set of discontinuities. However, in soft rocks, failure can occur along surfaces approaching to a circular failure surface. To better understand the position of potential sliding surface, a new method called simplex-finite stochastic tracking method is proposed. This method basically divides sliding surface into two parts: one is described by smooth curve obtained by random searching, the other one is polyline formed by the weak structural surface. Single or multiple sliding surfaces can be considered, and consequently several types of combined sliding surfaces can be simulated. The paper will adopt the arc-polyline to simulate potential sliding surface and analyze the searching process of sliding surface. Accordingly, software for slope stability analysis using this method was developed and applied in real cases. The results show that, using simplex-finite stochastic tracking method, it is possible to locate the position of a potential sliding surface in the slope.

  10. Sliding surface searching method for slopes containing a potential weak structural surface

    Institute of Scientific and Technical Information of China (English)

    Aijun Yao; Zhizhou Tian; Yongjun Jin

    2014-01-01

    Weak structural surface is one of the key factors controlling the stability of slopes. The stability of rock slopes is in general concerned with set of discontinuities. However, in soft rocks, failure can occur along surfaces approaching to a circular failure surface. To better understand the position of potential sliding surface, a new method called simplex-finite stochastic tracking method is proposed. This method basically divides sliding surface into two parts: one is described by smooth curve obtained by random searching, the other one is polyline formed by the weak structural surface. Single or multiple sliding surfaces can be considered, and consequently several types of combined sliding surfaces can be simu-lated. The paper will adopt the arc-polyline to simulate potential sliding surface and analyze the searching process of sliding surface. Accordingly, software for slope stability analysis using this method was developed and applied in real cases. The results show that, using simplex-finite stochastic tracking method, it is possible to locate the position of a potential sliding surface in the slope.

  11. Lunar Surface Potential Increases during Terrestrial Bow Shock Traversals

    Science.gov (United States)

    Collier, Michael R.; Stubbs, Timothy J.; Hills, H. Kent; Halekas, Jasper; Farrell, William M.; Delory, Greg T.; Espley, Jared; Freeman, John W.; Vondrak, Richard R.; Kasper, Justin

    2009-01-01

    Since the Apollo era the electric potential of the Moon has been a subject of interest and debate. Deployed by three Apollo missions, Apollo 12, Apollo 14 and Apollo 15, the Suprathermal Ion Detector Experiment (SIDE) determined the sunlit lunar surface potential to be about +10 Volts using the energy spectra of lunar ionospheric thermal ions accelerated toward the Moon. We present an analysis of Apollo 14 SIDE "resonance" events that indicate the lunar surface potential increases when the Moon traverses the dawn bow shock. By analyzing Wind spacecraft crossings of the terrestrial bow shock at approximately this location and employing current balancing models of the lunar surface, we suggest causes for the increasing potential. Determining the origin of this phenomenon will improve our ability to predict the lunar surface potential in support of human exploration as well as provide models for the behavior of other airless bodies when they traverse similar features such as interplanetary shocks, both of which are goals of the NASA Lunar Science Institute's Dynamic Response of the Environment At the Moon (DREAM) team.

  12. Reversible Compositional Control of Oxide Surfaces by Electrochemical Potentials

    KAUST Repository

    Mutoro, Eva

    2012-01-05

    Perovskite oxides can exhibit a wide range of interesting characteristics such as being catalytically active and electronically/ionically conducting, and thus, they have been used in a number of solid-state devices such as solid oxide fuel cells (SOFCs) and sensors. As the surface compositions of perovskites can greatly influence the catalytic properties, knowing and controlling their surface compositions is crucial to enhance device performance. In this study, we demonstrate that the surface strontium (Sr) and cobalt (Co) concentrations of perovskite-based thin films can be controlled reversibly at elevated temperatures by applying small electrical potential biases. The surface compositional changes of La 0.8Sr 0.2CoO 3-δ (LSC 113), (La 0.5Sr 0.5) 2CoO 4±δ (LSC 214), and LSC 214-decorated LSC 113 films (LSC 113/214) were investigated in situ by utilizing synchrotron-based X-ray photoelectron spectroscopy (XPS), where the largest changes of surface Sr were found for the LSC 113/214 surface. These findings offer the potential of reversibly controlling the surface functionality of perovskites. © 2011 American Chemical Society.

  13. Potential use of ground-based sensor technologies for weed detection.

    Science.gov (United States)

    Peteinatos, Gerassimos G; Weis, Martin; Andújar, Dionisio; Rueda Ayala, Victor; Gerhards, Roland

    2014-02-01

    Site-specific weed management is the part of precision agriculture (PA) that tries to effectively control weed infestations with the least economical and environmental burdens. This can be achieved with the aid of ground-based or near-range sensors in combination with decision rules and precise application technologies. Near-range sensor technologies, developed for mounting on a vehicle, have been emerging for PA applications during the last three decades. These technologies focus on identifying plants and measuring their physiological status with the aid of their spectral and morphological characteristics. Cameras, spectrometers, fluorometers and distance sensors are the most prominent sensors for PA applications. The objective of this article is to describe-ground based sensors that have the potential to be used for weed detection and measurement of weed infestation level. An overview of current sensor systems is presented, describing their concepts, results that have been achieved, already utilized commercial systems and problems that persist. A perspective for the development of these sensors is given. © 2013 Society of Chemical Industry.

  14. Chemical Characterization of Potentially Prebiotic Oligosaccharides in Brewed Coffee and Spent Coffee Grounds.

    Science.gov (United States)

    Tian, Tian; Freeman, Samara; Corey, Mark; German, J Bruce; Barile, Daniela

    2017-04-05

    Oligosaccharides are indigestible carbohydrates widely present in mammalian milk and in some plants. Milk oligosaccharides are associated with positive health outcomes; however, oligosaccharides in coffee have not been extensively studied. We investigated the oligosaccharides and their monomeric composition in dark roasted coffee beans, brewed coffee, and spent coffee grounds. Oligosaccharides with a degree of polymerization ranging from 3 to 15, and their constituent monosaccharides, were characterized and quantified. The oligosaccharides identified were mainly hexoses (potentially galacto-oligosaccharides and manno-oligosaccharides) containing a heterogeneous mixture of glucose, arabinose, xylose, and rhamnose. The diversity of oligosaccharides composition found in these coffee samples suggests that they could have selective prebiotic activity toward specific bacterial strains able to deconstruct the glycosidic bonds and utilize them as a carbon source.

  15. Mitigation potential of horizontal ground coupled heat pumps for current and future climatic conditions: UK environmental modelling and monitoring studies

    Science.gov (United States)

    García González, Raquel; Verhoef, Anne; Vidale, Pier Luigi; Gan, Guohui; Wu, Yupeng; Hughes, Andrew; Mansour, Majdi; Blyth, Eleanor; Finch, Jon; Main, Bruce

    2010-05-01

    An increased uptake of alternative low or non-CO2 emitting energy sources is one of the key priorities for policy makers to mitigate the effects of environmental change. Relatively little work has been undertaken on the mitigation potential of Ground Coupled Heat Pumps (GCHPs) despite the fact that a GCHP could significantly reduce CO2 emissions from heating systems. It is predicted that under climate change the most probable scenario is for UK temperatures to increase and for winter rainfall to become more abundant; the latter is likely to cause a general rise in groundwater levels. Summer rainfall may reduce considerably, while vegetation type and density may change. Furthermore, recent studies underline the likelihood of an increase in the number of heat waves. Under such a scenario, GCHPs will increasingly be used for cooling as well as heating. These factors will affect long-term performance of horizontal GCHP systems and hence their economic viability and mitigation potential during their life span ( 50 years). The seasonal temperature differences encountered in soil are harnessed by GCHPs to provide heating in the winter and cooling in the summer. The performance of a GCHP system will depend on technical factors (heat exchanger (HE) type, length, depth, and spacing of pipes), but also it will be determined to a large extent by interactions between the below-ground parts of the system and the environment (atmospheric conditions, vegetation and soil characteristics). Depending on the balance between extraction and rejection of heat from and to the ground, the soil temperature in the neighbourhood of the HE may fall or rise. The GROMIT project (GROund coupled heat pumps MITigation potential), funded by the Natural Environment Research Council (UK), is a multi-disciplinary research project, in collaboration with EarthEnergy Ltd., which aims to quantify the CO2 mitigation potential of horizontal GCHPs. It considers changing environmental conditions and combines

  16. Surface-Water and Ground-Water Interactions in the Central Everglades, Florida

    Science.gov (United States)

    Harvey, Judson W.; Newlin, Jessica T.; Krest, James M.; Choi, Jungyill; Nemeth, Eric A.; Krupa, Steven L.

    2004-01-01

    Recharge and discharge are hydrological processes that cause Everglades surface water to be exchanged for subsurface water in the peat soil and the underlying sand and limestone aquifer. These interactions are thought to be important to water budgets, water quality, and ecology in the Everglades. Nonetheless, relatively few studies of surface water and ground water interactions have been conducted in the Everglades, especially in its vast interior areas. This report is a product of a cooperative investigation conducted by the USGS and the South Florida Water Management District (SFWMD) aimed at developing and testing techniques that would provide reliable estimates of recharge and discharge in interior areas of WCA-2A (Water Conservation Area 2A) and several other sites in the central Everglades. The new techniques quantified flow from surface water to the subsurface (recharge) and the opposite (discharge) using (1) Darcy-flux calculations based on measured vertical gradients in hydraulic head and hydraulic conductivity of peat; (2) modeling transport through peat and decay of the naturally occurring isotopes 224Ra and 223Ra (with half-lives of 4 and 11 days, respectively); and (3) modeling transport and decay of naturally occurring and 'bomb-pulse' tritium (half-life of 12.4 years) in ground water. Advantages and disadvantages of each method for quantifying recharge and discharge were compared. In addition, spatial and temporal variability of recharge and discharge were evaluated and controlling factors identified. A final goal was to develop appropriately simplified (that is, time averaged) expressions of the results that will be useful in addressing a broad range of hydrological and ecological problems in the Everglades. Results were compared with existing information about water budgets from the South Florida Water Management Model (SFWMM), a principal tool used by the South Florida Water Management District to plan many of the hydrological aspects of the

  17. Ground-based RGB imaging to determine the leaf water potential of potato plants

    Science.gov (United States)

    Zakaluk, Robert F.

    The determination of plant water status from leaf water potential (Psi L) data obtained by conventional methods is impractical for meeting real time irrigation monitoring requirements. This research, undertaken first, in a greenhouse and then in the field, examined the use of artificial neural network (ANN) modeling of RGB (red green blue) images, captured by a ground-based, five mega pixel digital camera, to predict the leaf water potential of potato (Solanum tuberosum L). The greenhouse study examined cv. Russet Burbank, while the field study examined cv. Sangre. The protocol was similar in both studies: (1) images were acquired over different soil nitrate (N) and volumetric water content levels, (2) images were radiometrically calibrated, (3) green foliage was classified and extracted from the images, and (4) image transformations, and vegetation indices were calculated and transformed using principal components analysis (PCA). The findings from both studies were similar: (1) the R and G bands were more important than the B image band in the classification of green leaf pigment, (2) soil N showed an inverse linear relationship against leaf reflectance in the G image band, (3) the ANN model input neuron weights with more separation between soil N and PsiL were more important than other input neurons in predicting PsiL, and (4) the measured and predicted PsiL validation datasets were normally distributed with equal variances and means that were not significantly different. Based on these research findings, the ground-based digital camera proved to be an adequate sensor for image acquisition and a practical tool for acquiring data for predicting the PsiL of potato plants. Keywords: nitrogen, IHS transformation, chromaticity transformation, principal components, vegetation indices, remote sensing, artificial neural network, digital camera.

  18. Martian Surface Temperature and Spectral Response from the MSL REMS Ground Temperature Sensor

    Science.gov (United States)

    Martin-Torres, Javier; Martínez-Frías, Jesús; Zorzano, María-Paz; Serrano, María; Mendaza, Teresa; Hamilton, Vicky; Sebastián, Eduardo; Armiens, Carlos; Gómez-Elvira, Javier; REMS Team

    2013-04-01

    The Rover Environmental Monitoring Station (REMS) on the Mars Science Laboratory (MSL) offers the opportunity to explore the near surface atmospheric conditions and, in particular will shed new light into the heat budget of the Martian surface. This is important for studies of the atmospheric boundary layer (ABL), as the ground and air temperatures measured directly by REMS control the coupling of the atmosphere with the surface [Zurek et al., 1992]. This coupling is driven by solar insolation. The ABL plays an important role in the general circulation and the local atmospheric dynamics of Mars. One of the REMS sensors, the ground temperature sensor (GTS), provides the data needed to study the thermal inertia properties of the regolith and rocks beneath the MSL rover. The GTS includes thermopile detectors, with infrared bands of 8-14 µm and 16-20 µm [Gómez-Elvira et al., 2012]. These sensors are clustered in a single location on the MSL mast and the 8-14 µm thermopile sounds the surface temperature. The infrared radiation reaching the thermopile is proportional to the emissivity of the surface minerals across these thermal wavelengths. We have developed a radiative transfer retrieval method for the REMS GTS using a database of thermal infrared laboratory spectra of analogue minerals and their mixtures. [Martín Redondo et al. 2009, Martínez-Frías et al. 2012 - FRISER-IRMIX database]. This method will be used to assess the perfomance of the REMS GTS as well as determine, through the error analysis, the surface temperature and emissivity values where MSL is operating. Comparisons with orbiter data will be performed. References Gómez-Elvira et al. [2012], REMS: The Environmental Sensor Suite for the Mars Science Laboratory Rover, Space Science Reviews, Volume 170, Issue 1-4, pp. 583-640. Martín-Redondo et al. [2009] Journal of Environmental Monitoring 11:, pp. 1428-1432. Martínez-Frías et al. [2012] FRISER-IRMIX database http

  19. Ground Surface Deformation around Tehran due to Groundwater Recharge: InSAR Monitoring.

    Science.gov (United States)

    Gourmelen, N.; Peyret, M.; Fritz, J. F.; Cherry, J.

    2003-04-01

    Tehran is located on an active tectonic and seismic zone. The surface deformation monitoring provides a powerful tool for getting a better understanding of faults kinematics and mechanisms. Used in conjunction with GPS networks, InSAR (Interferometric Synthetic Aperture Radar) provides dense and precise deformation measurements which are essential for mapping complex heterogeneous deformation fields. Moreover, urban and arid areas preserve interferometric phase coherence. The archived acquisitions of ERS that span 9 months between September 1998 and June 1999 reveal wide areas of surface uplift (by as much as 9 cm). This vertical deformation (gradual in time) has probably no tectonic meaning but is rather the ground response to ground water recharge. These zones are all located dowstream of large alluvial fans like the one of Karaj. The variation of effective stress caused by intersticial water draining could explain such surface deformation. It can also be noticed that some faults act as boundary for these deformation zones and fluid motion. The understanding of this deformation is relevant for groundwater monitoring and urban developement management. It is also necessary for discriminating it from tectonic deformation that also occurs on this zone. Due to the lack of attitude control of satellite ERS-2 since February 2001, the last images acquired could not be combined with the former acquisitions. Nevertheless, we expect to be able to enrich our set of images in order to map tectonic deformation on a longer period and to monitor in a more continuous way the deformation due to groundwater evolution. This would allow to quantify the permanent and reversible part of this signal.

  20. He-, Ne-, and Ar-phosgene intermolecular potential energy surfaces

    DEFF Research Database (Denmark)

    Munteanu, Cristian R.; Henriksen, Christian; Felker, Peter M.

    2013-01-01

    Using the CCSD(T) model, we evaluated the intermolecular potential energy surfaces of the He-, Ne-, and Ar-phosgene complexes. We considered a representative number of intermolecular geometries for which we calculated the corresponding interaction energies with the augmented (He complex) and double...

  1. The ground state of long-range Schrodinger equations and static $q\\bar{q}$ potential

    CERN Document Server

    Beccaria, Matteo; Pallara, Diego

    2016-01-01

    Motivated by the recent results in arXiv:1601.05679 about the quark-antiquark potential in $\\mathcal N=4$ SYM, we reconsider the problem of computing the asymptotic weak-coupling expansion of the ground state energy of a certain class of 1d Schr\\"odinger operators $-\\frac{d^{2}}{dx^{2}}+\\lambda\\,V(x)$ with long-range potential $V(x)$. In particular, we consider even potentials obeying $\\int_{\\mathbb R}dx\\, V(x)<0$ with large $x$ asymptotics $V\\sim -a/x^{2}-b/x^{3}+\\cdots$. The associated Schr\\"odinger operator is known to admit a bound state for $\\lambda\\to 0^{+}$, but the binding energy is rigorously non-analytic at $\\lambda=0$. Its asymptotic expansion starts at order $\\mathcal O(\\lambda)$, but contains higher corrections $\\lambda^{n}\\,\\log^{m}\\lambda$ with all $0\\le m\\le n-1$ and standard Rayleigh-Schr\\"odinger perturbation theory fails order by order in $\\lambda$. We discuss various analytical tools to tame this problem and provide the general expansion of the binding energy at $\\mathcal O(\\lambda^{3})...

  2. Potential of Laser Induced Breakdown Spectroscopy for analyzing the quality of unroasted and ground coffee

    Science.gov (United States)

    Silva, Tiago Varão; Hubinger, Silviane Zanni; Gomes Neto, José Anchieta; Milori, Débora Marcondes Bastos Pereira; Ferreira, Ednaldo José; Ferreira, Edilene Cristina

    2017-09-01

    Coffee is an important commodity and a very popular beverage around the world. Its economic value as well as beverage quality are strongly dependent of the quality of beans. The presence of defective beans in coffee blends has caused a negative impact on the beverage Global Quality (GQ) assessed by cupping tests. The main defective beans observed in the productive chain has been those Blacks, Greens and Sours (BGS). Chemical composition of BGS has a damaging impact on beverage GQ. That is why analytical tools are needed for monitoring and controlling the GQ in coffee agro-industry. Near Infrared Spectroscopy (NIRS) has been successfully applied for assessment of coffee quality. Another potential technique for direct, clean and fast measurement of coffee GQ is Laser Induced Breakdown Spectroscopy (LIBS). Elements and diatomic molecules commonly present in organic compounds (structure) can be assessed by using LIBS. In this article is reported an evaluation of LIBS for the main interferents of GQ (BGS defects). Results confirm the great potential of LIBS for discriminating good beans from those with BGS defects by using emission lines of C, CN, C2 and N. Most importantly, some emission lines presented strong linear correlation (r > 0.9) with NIRS absorption bands assigned to proteins, lipids, sugar and carboxylic acids, suggesting LIBS potential to estimate these compounds in unroasted and ground coffee samples.

  3. Road impacts on the Baca National Wildlife Refuge, Colorado, with emphasis on effects to surface- and shallow ground-water hydrology - A literature review

    Science.gov (United States)

    Andersen, Douglas C.

    2007-01-01

    A review of published research on unpaved road effects on surface-water and shallow ground-water hydrology was undertaken to assist the Baca National Wildlife Refuge, Colorado, in understanding factors potentially influencing refuge ecology. Few studies were found that addressed hydrological effects of roads on a comparable area of shallow slope in a semiarid region. No study dealt with road effects on surface- and ground-water supplies to ephemeral wetlands, which on the refuge are sustained by seasonal snowmelt in neighboring mountains. Road surfaces increase runoff, reduce infiltration, and serve as a sediment source. Roadbeds can interfere with normal surface- and ground-water flows and thereby influence the quantity, timing, and duration of water movement both across landscapes and through the soil. Hydrologic effects can be localized near the road as well as widespread and distant. The number, arrangement, and effectiveness of road-drainage structures (culverts and other devices) largely determine the level of hydrologic alteration produced by a road. Undesirable changes to natural hydrologic patterns can be minimized by considering potential impacts during road design, construction, and maintenance. Road removal as a means to restore desirable hydrologic conditions to landscapes adversely affected by roads has yet to be rigorously evaluated.

  4. Potential energy surface of triplet N{sub 2}O{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Varga, Zoltan; Meana-Pañeda, Rubén; Song, Guoliang; Paukku, Yuliya; Truhlar, Donald G., E-mail: truhlar@umn.edu [Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431 (United States)

    2016-01-14

    We present a global ground-state triplet potential energy surface for the N{sub 2}O{sub 2} system that is suitable for treating high-energy vibrational-rotational energy transfer and collision-induced dissociation. The surface is based on multi-state complete-active-space second-order perturbation theory/minimally augmented correlation-consistent polarized valence triple-zeta electronic structure calculations plus dynamically scaled external correlation. In the multireference calculations, the active space has 14 electrons in 12 orbitals. The calculations cover nine arrangements corresponding to dissociative diatom-diatom collisions of N{sub 2}, O{sub 2}, and nitric oxide (NO), the interaction of a triatomic molecule (N{sub 2}O and NO{sub 2}) with the fourth atom, and the interaction of a diatomic molecule with a single atom (i.e., the triatomic subsystems). The global ground-state potential energy surface was obtained by fitting the many-body interaction to 54 889 electronic structure data points with a fitting function that is a permutationally invariant polynomial in terms of bond-order functions of the six interatomic distances.

  5. Investigating the composition of Potentially Hazardous Asteroids with the NEO-SURFACE survey

    Science.gov (United States)

    Ieva, S.; Dotto, E.; Perna, D.; Barucci, M. A.; Bernardi, F.; Perozzi, E.; Micheli, M.; Mazzotta Epifani, E.; Brucato, J. R.; Fornasier, S.; De Luise, F.; Rossi, A.

    2015-10-01

    There is a high degree of diversity among the physical properties of the Potentially Hazardous asteroids (PHAs). For these objects, the physical characterization is essential to define a successful mitigation mission, therefore ground-based surveys like NEO-SURFACE could provide a fundamental contribution. Our analysis suggest a prevalence of silicate S-types in the PHA population, which could be due in principle to the high efficiency of the transport mechanisms in the inner main belt, or to an observational bias due to the fact that S-types are brighter.

  6. Geologic Evidence for Late-Stage Equatorial Surface and Ground Ice on Mars

    Science.gov (United States)

    Chapman, M. G.

    2003-12-01

    New imagery data from the Mars Observer Camera suggest that the equatorial canyon of Valles Marineris contained surface and ground ice relatively late in Martian history. Some troughs (or chasmata) of Valles Marineris contain large mounds and mesas of interior layered deposits (ILDs) that formed in the Late Hesperian to Early Amazonian. Although the origin of the ILDs remains controversial, their characteristics suggest that the strongest hypotheses origin are lacustrine or volcanic processes; some workers have suggested a compromise origin, noting that many MOC observations of ILDs are similar to those of terrestrial sub-ice volcanoes that erupt in meltwater lakes. Lacustrine deposition and sub-ice volcanism require that chamata water or ice would have had to remain stable on the surface long enough to form either (1) extremely thick (1 km to > 4 km) deposits of fine-grained suspended lacustrine materials or (2) numerous sub-ice volcanic edifices with heights that compare to those of Hawaiian oceanic volcanoes. However, a dust cover on top of ice or an ice-covered lake could aid in preventing rapid sublimation. If the ILDs are sub-ice volcanoes than new MOLA topographic data can be used to (1) measure the heights of their subaerial caprock and (2) estimate corresponding volumes of ice. For example, the largest ILD mound in the 113,275 km3 void of Juventae Chasma resembles a capped sub-ice volcanic ridge. The mound is about 2 km high; with the highest point of the cap reaching an elevation of about +80 m. GIS measurement indicate that the maximum volume of ice below the elevation of +80 m is 56,423 km3, so roughly half of the Chasma could have been filled with ice. If the ILDs are lacustrine, then the heights of some other mounds that rival the surrounding plateau elevation would have required a volume of water almost equal to their enclosing chasma. Later in the Amazonian, after sublimation of any putative surface water or ice, MOC imagery attests to ground ice

  7. Communication: Fitting potential energy surfaces with fundamental invariant neural network

    Science.gov (United States)

    Shao, Kejie; Chen, Jun; Zhao, Zhiqiang; Zhang, Dong H.

    2016-08-01

    A more flexible neural network (NN) method using the fundamental invariants (FIs) as the input vector is proposed in the construction of potential energy surfaces for molecular systems involving identical atoms. Mathematically, FIs finitely generate the permutation invariant polynomial (PIP) ring. In combination with NN, fundamental invariant neural network (FI-NN) can approximate any function to arbitrary accuracy. Because FI-NN minimizes the size of input permutation invariant polynomials, it can efficiently reduce the evaluation time of potential energy, in particular for polyatomic systems. In this work, we provide the FIs for all possible molecular systems up to five atoms. Potential energy surfaces for OH3 and CH4 were constructed with FI-NN, with the accuracy confirmed by full-dimensional quantum dynamic scattering and bound state calculations.

  8. A Comprehensive Laboratory Study to Improve Ground Truth Calibration of Remotely Sensed Near-Surface Soil Moisture

    Science.gov (United States)

    Babaeian, E.; Tuller, M.; Sadeghi, M.; Sheng, W.; Jones, S. B.

    2016-12-01

    Optical satellite and airborne remote sensing (RS) have been widely applied for characterization of large-scale surface soil moisture distributions. However, despite the excellent spatial resolution of RS data, the electromagnetic radiation within the optical bands (400-2500 nm) penetrates the soil profile only to a depth of a few millimeters; hence obtained moisture estimates are limited to the soil surface region. Furthermore, moisture sensor networks employed for ground truth calibration of RS observations commonly exhibit very limited spatial resolution, which consequently leads to significant discrepancies between RS and ground truth observations. To better understand the relationship between surface and near-surface soil moisture, we employed a benchtop hyperspectral line-scan imaging system to generate high resolution surface reflectance maps during evaporation from soil columns filled with source soils covering a wide textural range and instrumented with a novel time domain reflectometry (TDR) sensor array that allows monitoring of near surface moisture at 0.5-cm resolution. A recently developed physical model for surface soil moisture predictions from shortwave infrared reflectance was applied to estimate surface soil moisture from surface reflectance and to explore the relationship between surface and near-surface moisture distributions during soil drying. Preliminary results are very promising and their applicability for ground truth calibration of RS observations will be discussed.

  9. Documentation of the Santa Clara Valley regional ground-water/surface-water flow model, Santa Clara Valley, California

    Science.gov (United States)

    Hanson, R.T.; Li, Zhen; Faunt, C.C.

    2004-01-01

    The Santa Clara Valley is a long, narrow trough extending about 35 miles southeast from the southern end of San Francisco Bay where the regional alluvial-aquifer system has been a major source of water. Intensive agricultural and urban development throughout the 20th century and related ground-water development resulted in ground-water-level declines of more than 200 feet and land subsidence of as much as 12.7 feet between the early 1900s and the mid-1960s. Since the 1960s, Santa Clara Valley Water District has imported surface water to meet growing demands and reduce dependence on ground-water supplies. This importation of water has resulted in a sustained recovery of the ground-water flow system. To help support effective management of the ground-water resources, a regional ground-water/surface-water flow model was developed. This model simulates the flow of ground water and surface water, changes in ground-water storage, and related effects such as land subsidence. A numerical ground-water/surface-water flow model of the Santa Clara Valley subbasin of the Santa Clara Valley was developed as part of a cooperative investigation with the Santa Clara Valley Water District. The model better defines the geohydrologic framework of the regional flow system and better delineates the supply and demand components that affect the inflows to and outflows from the regional ground-water flow system. Development of the model includes revisions to the previous ground-water flow model that upgraded the temporal and spatial discretization, added source-specific inflows and outflows, simulated additional flow features such as land subsidence and multi-aquifer wellbore flow, and extended the period of simulation through September 1999. The transient-state model was calibrated to historical surface-water and ground-water data for the period 197099 and to historical subsidence for the period 198399. The regional ground-water flow system consists of multiple aquifers that are grouped

  10. Ground Plane and Near-Surface Thermal Analysis for NASA's Constellation Program

    Science.gov (United States)

    Gasbarre, Joseph F.; Amundsen, Ruth M.; Scola, Salvatore; Leahy, Frank F.; Sharp, John R.

    2008-01-01

    Most spacecraft thermal analysis tools assume that the spacecraft is in orbit around a planet and are designed to calculate solar and planetary fluxes, as well as radiation to space. On NASA Constellation projects, thermal analysts are also building models of vehicles in their pre-launch condition on the surface of a planet. This process entails making some modifications in the building and execution of a thermal model such that the radiation from the planet, both reflected albedo and infrared, is calculated correctly. Also important in the calculation of pre-launch vehicle temperatures are the natural environments at the vehicle site, including air and ground temperatures, sky radiative background temperature, solar flux, and optical properties of the ground around the vehicle. A group of Constellation projects have collaborated on developing a cohesive, integrated set of natural environments that accurately capture worst-case thermal scenarios for the pre-launch and launch phases of these vehicles. The paper will discuss the standardization of methods for local planet modeling across Constellation projects, as well as the collection and consolidation of natural environments for launch sites. Methods for Earth as well as lunar sites will be discussed.

  11. Two decades of temperature-time monitoring experiment: air - ground surface - shallow subsurface interactions

    Science.gov (United States)

    Cermak, Vladimir; Dedecek, Petr; Safanda, Jan; Kresl, Milan

    2014-05-01

    Long-term observations (1994-2013) of air and shallow ground temperatures at borehole Prague-Sporilov (50º02'28.5"E, 14º28'40.2"N, 274 m a.s.l.) have been thoroughly analyzed to understand the relationship between these quantities and to describe the mechanism of heat transport at the land-atmosphere boundary layer. Data provided a surprisingly small mean ground-air temperature offset of only 0.31 K with no clear annual course and with the offset value changing irregularly even on a daily scale. Such value is substantially lower than similar values (1-2 K and more) found elsewhere, but may well characterize a mild temperate zone, when all so far available information referred rather to southern locations. Borehole data were correlated with similar observations in a polygon-site under four types of surface conditions (grass, soil, sand and asphalt) completed with registration of meteorological variables (wind direction & velocity, air & soil humidity, direct & reflected solar radiation, precipitation and snow cover). The "thermal orbits" technique proved to be an effective tool for the fast qualitative diagnostics of the thermal regime in the subsurface (conductive versus non-conductive).

  12. Valorization of spent coffee grounds recycling as a potential alternative fuel resource in Turkey: An experimental study.

    Science.gov (United States)

    Atabani, A E; Mercimek, S M; Arvindnarayan, Sundaram; Shobana, Sutha; Kumar, Gopalakrishnan; Cadir, Mehmet; Al-Muhatseb, Ala'a H

    2017-08-22

    In this study, recycling of spent coffee grounds (SCG) as a potential feedstock for alternative fuels production and compounds of added value in Turkey was assessed. The average oil content was found (≈ 13% w/w). All samples (before and after extraction) were tested for SEM, DSC, TGA, XRD, calorific value, surface analysis and porosity, FT-IR and elemental analysis to assess their potential towards fuel properties. Elemental analysis indicated that carbon represents the highest percentage (49.59% and 46.42% respectively), followed by Nitrogen (16.7% and 15.5%), Hydrogen (6.74% and 6.04%) and Sulfur (0.851% and 0.561%). These results indicate that SCG can be utilized as compost as it is rich in nitrogen. Properties of the extracted oil were examined, followed by biodiesel production. The quality of biodiesel was compared with ASTM D6751 standards and all the properties complied with standard specifications. The fatty acid compositions were analyzed by Gas chromatography. It is observed that coffee waste methyl ester (CWME) is mainly comprised of palmitic (35.8%) and arachidic (44.6%) acids which are saturated fatty acids. The low degree of unsaturation provides an excellent oxidation stability (10.4 h). CWME has also excellent cetane number, higher heating value and iodine value with poor cold flow properties. The studies also investigated blending of biodiesel with euro diesel and butanol. Following this, a remarkable improvement in cloud and pour points of biodiesel was obtained. Spent coffee grounds after oil extraction is an ideal material for garden fertilizer, feedstock for ethanol, biogas production and as fuel pellets. The outcome of such research work produces valuable insights on the recycling importance of SCG in Turkey. Implication Coffee is a huge industry that has been widely used due to its refreshing properties. This industry generates large quantities of waste. Therefore, recycling of spent coffee grounds for producing alternative fuels and

  13. Very-low-frequency resistivity, self-potential and ground temperature surveys on Taal volcano (Philippines): Implications for future activity

    Science.gov (United States)

    Zlotnicki, J.; Vargemezis, G.; Johnston, M. J. S.; Sasai, Y.; Reniva, P.; Alanis, P.

    2017-06-01

    Taal volcano is one of the most dangerous volcanoes in the Philippines. Thirty-three eruptions have occurred through historical time with several exhibiting cataclysmic phases. Most recent eruptions are confined to Volcano Island located within the prehistoric Taal collapse caldera that is now filled by Taal Lake. The last eruptive activity from 1965 to 1977 took place from Mt. Tabaro, about 2 km to the southwest of the Main Crater center. Since this time, episodes of seismic activity, ground deformation, gas release, surface fissuring, fumarole activity and temperature changes are recorded periodically around the main crater, but no major eruption has occurred. This period of quiescence is the third longest period without eruptive activity since 1572. In March 2010, a campaign based on Very-Low-Frequency (VLF) resistivity surveys together with repeated surveys of self-potential, ground temperature and fissure activity was intensified and the results compared to a large-scale Electrical Resistivity Tomography experiment. This work fortunately occurred before, within and after a new seismovolcanic crisis from late April 2010 to March 2011. The joint analysis of these new data, together with results from previous magnetotelluric soundings, allows a better description of the electrical resistivity and crustal structure beneath the Main Crater down to a depth of several kilometers. No indication of growth of the two geothermal areas located on both sides of the northern crater rim was apparent from 2005 to March 2010. These areas appear controlled by active fissures, opened during the 1992 and 1994 crises, that dip downward towards the core of the hydrothermal system located at about 2.5 km depth beneath the crater. Older mineralized fissures at lower elevations to the North of the geothermal areas also dip downward under the crater. Repeated self-potential and ground temperature surveys completed between 2005 and 2015 show new geothermal and hydrothermal activity in

  14. Surface roughening of ground fused silica processed by atmospheric inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Qiang; Li, Na; Wang, Jun; Wang, Bo, E-mail: bradywang@hit.edu.cn; Li, Guo; Ding, Fei; Jin, Huiliang

    2015-06-30

    Highlights: • The morphology evolution of ground fused silica, processed by atmospheric plasma, was investigated experimentally. • The roughness development results from opening and coalescing of the plasma-etched cracks. • The shapes of grain-like etched pits are the results of the adjacent cracks coalescing with one another. • The descent of the pits density is due to some smaller etched pits that are swallowed up by larger pits. • Leading role in surface smoothing is laterally etching away the side walls of the intersecting pits. - Abstract: Subsurface damage (SSD) is a defect that is inevitably induced during mechanical processes, such as grinding and polishing. This defect dramatically reduces the mechanical strength and the laser damage thresholds of optical elements. Compared with traditional mechanical machining, atmospheric pressure plasma processing (APPP) is a relatively novel technology that induces almost no SSD during the processing of silica-based optical materials. In this paper, a form of APPP, inductively coupled plasma (ICP), is used to process fused silica substrates with fluorocarbon precursor under atmospheric pressure. The surface morphology evolution of ICP-processed substrates was observed and characterized by confocal laser scanning microscope (CLSM), field emission scanning electron microscope (SEM), and atomic force microscopy (AFM). The results show that the roughness evolves with the etching depth, and the roughness evolution is a single-peaked curve. This curve results from the opening and the coalescing of surface cracks and fractures. The coalescence procedure of these microstructures was simulated with two common etched pits on a polished fused silica surface. Understanding the roughness evolution of plasma-processed surface might be helpful in optimizing the optical fabrication chain that contains APPP.

  15. Can atom-surface potential measurements test atomic structure models?

    Science.gov (United States)

    Lonij, Vincent P A; Klauss, Catherine E; Holmgren, William F; Cronin, Alexander D

    2011-06-30

    van der Waals (vdW) atom-surface potentials can be excellent benchmarks for atomic structure calculations. This is especially true if measurements are made with two different types of atoms interacting with the same surface sample. Here we show theoretically how ratios of vdW potential strengths (e.g., C₃(K)/C₃(Na)) depend sensitively on the properties of each atom, yet these ratios are relatively insensitive to properties of the surface. We discuss how C₃ ratios depend on atomic core electrons by using a two-oscillator model to represent the contribution from atomic valence electrons and core electrons separately. We explain why certain pairs of atoms are preferable to study for future experimental tests of atomic structure calculations. A well chosen pair of atoms (e.g., K and Na) will have a C₃ ratio that is insensitive to the permittivity of the surface, whereas a poorly chosen pair (e.g., K and He) will have a ratio of C₃ values that depends more strongly on the permittivity of the surface.

  16. Environmental surface cleanliness and the potential for contamination during handwashing.

    Science.gov (United States)

    Griffith, Christopher J; Malik, Rifhat; Cooper, Rose A; Looker, Nick; Michaels, Barry

    2003-04-01

    Effective handwashing (including drying) is important in infection control. The ability of the various stages of handwashing to decrease skin-surface microbial counts has been documented. However, an important element, environmental surface cleanliness, and the potential for contamination of hands during the process has not been well studied or quantified. An examination of the adenosine triphosphate (a measure of residual organic soil), bacterial, and staphylococcal load on ward handwash station surfaces, which could be touched during handwashing, is reported. Hand contact surfaces tested consisted of approximately 620 each of: faucet handles, soap dispenser activator mechanisms, and folded paper-towel dispenser exits. Failure rates in excess of benchmark clean values were higher with adenosine triphosphate assays than microbial counts. This could indicate the presence of a higher level of general organic debris (eg, skin cells) as opposed to microbial contamination or could reflect greater assay sensitivity. Faucet handles were more likely to be contaminated and be in excess of benchmark values than paper-towel dispenser exits. However, the latter are likely to be the final surface touched during the handwashing process and overall nearly 20% were above microbiologic benchmark values. Many of the organisms isolated were staphylococci and the results are discussed within the context of microbial cross-contamination and potential pathogen spread.

  17. Numerical modelling of ground-borne noise and vibration in buildings due to surface rail traffic

    Science.gov (United States)

    Fiala, P.; Degrande, G.; Augusztinovicz, F.

    2007-04-01

    This paper deals with the numerical computation of the structural and acoustic response of a building to an incoming wave field generated by high-speed surface railway traffic. The source model consists of a moving vehicle on a longitudinally invariant track, coupled to a layered ground modelled with a boundary element formulation. The receiver model is based on a substructuring formulation and consists of a boundary element model of the soil and a finite element model of the structure. The acoustic response of the building's rooms is computed by means of a spectral finite element formulation. The paper investigates the structural and acoustic response of a multi-story portal frame office building up to a frequency of 150 Hz to the passage of a Thalys high-speed train at constant velocity. The isolation performance of three different vibration countermeasures: a floating-floor, a room-in-room, and base-isolation, are examined.

  18. Sampling and analysis for radon-222 dissolved in ground water and surface water

    Science.gov (United States)

    DeWayne, Cecil L.; Gesell, T.F.

    1992-01-01

    Radon-222 is a naturally occurring radioactive gas in the uranium-238 decay series that has traditionally been called, simply, radon. The lung cancer risks associated with the inhalation of radon decay products have been well documented by epidemiological studies on populations of uranium miners. The realization that radon is a public health hazard has raised the need for sampling and analytical guidelines for field personnel. Several sampling and analytical methods are being used to document radon concentrations in ground water and surface water worldwide but no convenient, single set of guidelines is available. Three different sampling and analytical methods - bubbler, liquid scintillation, and field screening - are discussed in this paper. The bubbler and liquid scintillation methods have high accuracy and precision, and small analytical method detection limits of 0.2 and 10 pCi/l (picocuries per liter), respectively. The field screening method generally is used as a qualitative reconnaissance tool.

  19. Existence and Concentration of Ground States of Coupled Nonlinear Schr(o)dinger Equations with Bounded Potentials

    Institute of Scientific and Technical Information of China (English)

    Gongming WEI

    2008-01-01

    A 2-coupled nonlinear Schr(o)dinger equations with bounded varying potentials and strongly attractive interactions is considered.When the attractive interaction is strong enough,the existence of a ground state for sufficiently small Planck constant is proved.As the Planck constant approaches zero,it is proved that one of the components concentrates at a minimum point of the ground state energy function which is defined in Section 4.

  20. Surface Properties and Characteristics of Mars Landing Sites from Remote Sensing Data and Ground Truth

    Science.gov (United States)

    Golombek, M. P.; Haldemann, A. F.; Simpson, R. A.; Furgason, R. L.; Putzig, N. E.; Huertas, A.; Arvidson, R. E.; Heet, T.; Bell, J. F.; Mellon, M. T.; McEwen, A. S.

    2008-12-01

    Surface characteristics at the six sites where spacecraft have successfully landed on Mars can be related favorably to their signatures in remotely sensed data from orbit and from the Earth. Comparisons of the rock abundance, types and coverage of soils (and their physical properties), thermal inertia, albedo, and topographic slope all agree with orbital remote sensing estimates and show that the materials at the landing sites can be used as ground truth for the materials that make up most of the equatorial and mid- to moderately high-latitude regions of Mars. The six landing sites sample two of the three dominant global thermal inertia and albedo units that cover ~80% of the surface of Mars. The Viking, Spirit, Mars Pathfinder, and Phoenix landing sites are representative of the moderate to high thermal inertia and intermediate to high albedo unit that is dominated by crusty, cloddy, blocky or frozen soils (duricrust that may be layered) with various abundances of rocks and bright dust. The Opportunity landing site is representative of the moderate to high thermal inertia and low albedo surface unit that is relatively dust free and composed of dark eolian sand and/or increased abundance of rocks. Rock abundance derived from orbital thermal differencing techniques in the equatorial regions agrees with that determined from rock counts at the surface and varies from ~3-20% at the landing sites. The size-frequency distributions of rocks >1.5 m diameter fully resolvable in HiRISE images of the landing sites follow exponential models developed from lander measurements of smaller rocks and are continuous with these rock distributions indicating both are part of the same population. Interpretation of radar data confirms the presence of load bearing, relatively dense surfaces controlled by the soil type at the landing sites, regional rock populations from diffuse scattering similar to those observed directly at the sites, and root-mean-squared slopes that compare favorably

  1. Ground Boundary Conditions for Thermal Convection Over Horizontal Surfaces at High Rayleigh Numbers

    Science.gov (United States)

    Hanjalić, K.; Hrebtov, M.

    2016-07-01

    We present "wall functions" for treating the ground boundary conditions in the computation of thermal convection over horizontal surfaces at high Rayleigh numbers using coarse numerical grids. The functions are formulated for an algebraic-flux model closed by transport equations for the turbulence kinetic energy, its dissipation rate and scalar variance, but could also be applied to other turbulence models. The three-equation algebraic-flux model, solved in a T-RANS mode ("Transient" Reynolds-averaged Navier-Stokes, based on triple decomposition), was shown earlier to reproduce well a number of generic buoyancy-driven flows over heated surfaces, albeit by integrating equations up to the wall. Here we show that by using a set of wall functions satisfactory results are found for the ensemble-averaged properties even on a very coarse computational grid. This is illustrated by the computations of the time evolution of a penetrative mixed layer and Rayleigh-Bénard (open-ended, 4:4:1 domain) convection, using 10 × 10 × 100 and 10 × 10 × 20 grids, compared also with finer grids (e.g. 60 × 60 × 100), as well as with one-dimensional treatment using 1 × 1 × 100 and 1 × 1 × 20 nodes. The approach is deemed functional for simulations of a convective boundary layer and mesoscale atmospheric flows, and pollutant transport over realistic complex hilly terrain with heat islands, urban and natural canopies, for diurnal cycles, or subjected to other time and space variations in ground conditions and stratification.

  2. Evaluation of the toxicological properties of ground- and surface-water samples from the Aral Sea Basin

    Energy Technology Data Exchange (ETDEWEB)

    Bosch, K. [University of Salzburg, Department of Cell Biology, Hellbrunnerstr. 34, A-5020 Salzburg (Austria); Erdinger, L. [University of Heidelberg, Department for Hygiene and Medical Microbiology, Heidelberg (Germany); Ingel, F. [Russian Academy of Medical Sciences, A.N.Sysin Institute of Human Ecology and Environmental Hygiene, Moscow (Russian Federation); Khussainova, S. [Scientific Center of Pediatrics and Chrildren' s Surgery, Almaty (Kazakhstan); Utegenova, E. [Kazakh Sanitary-Epidemiological Station, Almaty (Kazakhstan); Bresgen, N. [University of Salzburg, Department of Cell Biology, Hellbrunnerstr. 34, A-5020 Salzburg (Austria); Eckl, P.M. [University of Salzburg, Department of Cell Biology, Hellbrunnerstr. 34, A-5020 Salzburg (Austria)]. E-mail: peter.eckl@sbg.ac.at

    2007-03-01

    In order to determine whether there is a potential health risk associated with the water supply in the Aral Sea Basin, ground- and surface-water samples were collected in and around Aralsk and from the Aral Sea in 2002. Water samples from Akchi, a small town close to Almaty, served as controls. Bioassays with different toxicological endpoints were employed to assess the general toxicological status. Additionally, the samples were analysed for microbial contamination. The samples were tested in the primary hepatocyte assay for their potential to induce micronuclei and chromosomal aberrations as cumulative indicators for genotoxicity. In parallel, the effects on cell proliferation evidenced by mitotic index and cytotoxicity such as the appearance of necrotic and apoptotic cells, were determined. Furthermore, samples were examined using the Microtox assay for general toxicity. Chemical analysis according to European regulations was performed and soil and water samples were analysed for DDT and DDE. The results obtained indicated no increased cyto- or genotoxic potential of the water samples, nor levels of DDT or DDE exceeding the thresholds levels suggested by WHO. Our data therefore do not support the hypothesis that the contamination of the drinking water in and around Aralsk is responsible for the health effects previously described such as increased rates of liver disease and in particular liver cancer. Microbiological analysis, however, revealed the presence of contamination in most samples analysed.

  3. Scalable and Detail-Preserving Ground Surface Reconstruction from Large 3D Point Clouds Acquired by Mobile Mapping Systems

    Science.gov (United States)

    Craciun, D.; Serna Morales, A.; Deschaud, J.-E.; Marcotegui, B.; Goulette, F.

    2014-08-01

    The currently existing mobile mapping systems equipped with active 3D sensors allow to acquire the environment with high sampling rates at high vehicle velocities. While providing an effective solution for environment sensing over large scale distances, such acquisition provides only a discrete representation of the geometry. Thus, a continuous map of the underlying surface must be built. Mobile acquisition introduces several constraints for the state-of-the-art surface reconstruction algorithms. Smoothing becomes a difficult task for recovering sharp depth features while avoiding mesh shrinkage. In addition, interpolation-based techniques are not suitable for noisy datasets acquired by Mobile Laser Scanning (MLS) systems. Furthermore, scalability is a major concern for enabling real-time rendering over large scale distances while preserving geometric details. This paper presents a fully automatic ground surface reconstruction framework capable to deal with the aforementioned constraints. The proposed method exploits the quasi-flat geometry of the ground throughout a morphological segmentation algorithm. Then, a planar Delaunay triangulation is applied in order to reconstruct the ground surface. A smoothing procedure eliminates high frequency peaks, while preserving geometric details in order to provide a regular ground surface. Finally, a decimation step is applied in order to cope with scalability constraints over large scale distances. Experimental results on real data acquired in large urban environments are presented and a performance evaluation with respect to ground truth measurements demonstrate the effectiveness of our method.

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

    Science.gov (United States)

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

    2016-04-01

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

  5. Monitoring surface geothermal features using time series of aerial and ground-based photographs

    Science.gov (United States)

    Bromley, C.; van Manen, S. M.; Graham, D.

    2010-12-01

    Geothermal systems are of high conservation and scientific value and monitoring of these is an important management tool to assess natural variations and changes resulting from development and utilization. This study examines time series of aerial and ground-based photographs of geothermal areas within the Taupo Volcanic Zone, New Zealand. A time series of aerial photographs from 1946-2007 of the Broadlands Road Scenic Reserve (Taupo, New Zealand) highlights large changes to this small area as the result of the start of geothermal fluid production for the nearby Wairakei power plant in 1958 and other causes. Prior to the opening of the plant the area was not geothermally active, but expansion of steam zones due to pressure drawdown has resulted in significant thermal changes in the subsurface. These subsurface thermal changes are evident in the aerial photographs as the appearance of hydrothermal eruption craters and areas of thermal bare ground, which are too hot for vegetation to grown on. In addition, in the late 1960’s thermotolerant vegetation started to establish itself in the adjacent area. Changes in the surface area covered by each of these, reflect changes in the geothermal system as well as changes in management (e.g. exclusion of livestock), and a time series of these changes has been produced using ArcMap™. Monthly photographs of surface geothermal expressions in the Rotorua area show changes in colour and size of chloride springs with time. Colour and size changes are difficult to quantify due to varying exposure settings, weather conditions, and vantage points. However, these qualitative descriptions can be combined with quantitative time series such as temperature measurements, to provide better insight into surface changes that have occurred at this geothermal field. This study highlights the value of both qualitative and quantitative data that can be obtained from time series of photographs, including photographs that were obtained before the

  6. Reducing multisensor monthly mean aerosol optical depth uncertainty: 2. Optimal locations for potential ground observation deployments

    Science.gov (United States)

    Li, Jing; Li, Xichen; Carlson, Barbara E.; Kahn, Ralph A.; Lacis, Andrew A.; Dubovik, Oleg; Nakajima, Teruyuki

    2017-04-01

    Surface remote sensing of aerosol properties provides "ground truth" for satellite and model validation and is an important component of aerosol observation system. Due to the different characteristics of background aerosol variability, information obtained at different locations usually has different spatial representativeness, implying that the location should be carefully chosen so that its measurement could be extended to a greater area. In this study, we present an objective observation array design technique that automatically determines the optimal locations with the highest spatial representativeness based on the Ensemble Kalman Filter (EnKF) theory. The ensemble is constructed using aerosol optical depth (AOD) products from five satellite sensors. The optimal locations are solved sequentially by minimizing the total analysis error variance, which means that observations at these locations will reduce the background error variance to the largest extent. The location determined by the algorithm is further verified to have larger spatial representativeness than some other arbitrary location. In addition to the existing active Aerosol Robotic Network (AERONET) sites, the 40 selected optimal locations are mostly concentrated on regions with both high AOD inhomogeneity and its spatial representativeness, namely, the Sahel, South Africa, East Asia, and North Pacific Islands. These places should be the focuses of establishing future AERONET sites in order to further reduce the uncertainty in the monthly mean AOD. Observations at these locations contribute to approximately 50% of the total background uncertainty reduction.

  7. Calculating vibrational spectra using modified Shepard interpolated potential energy surfaces.

    Science.gov (United States)

    Evenhuis, Christian R; Manthe, Uwe

    2008-07-14

    A potential energy interpolation approach based on modified Shepard interpolation and specifically designed for calculation of vibrational states is presented. The importance of the choice of coordinates for the rate of convergence is demonstrated. Studying the vibrational states of the water molecule as a test case, a coordinate system comprised of inverse bond distances and trigonometric functions of the bond angle is found to be particularly efficient. Different sampling schemes used to locate the reference points in the modified Shepard interpolation are investigated. A final scheme is recommended, which allows the construction of potential energy surfaces to sub-wave-number accuracy.

  8. Quantum mechanics of effective potential at a metal surface

    Science.gov (United States)

    Solomatin, Alexander

    In this thesis we study the nonuniform electron density system at a metal-vacuum interface via the corresponding local effective potential confining the electrons, the metal being represented by the jellium and structureless pseudopotential models. The study is performed within conventional Kohn-Sham (KS) density-functional theory and its recently derived quantum-mechanical interpretation. In the latter, properties are determined in terms of the separate electron correlations due to the Pauli exclusion principle, Coulomb repulsion and the correlation contribution to the kinetc energy. We have derived the exact analytical structure, valid for self-consistent orbitals, of the KS theory exchange potential in the classically forbidden region. This structure is image-potential-like of the form -alphasb{KS,x}(beta)chi where the parameter betasp2 is the ratio of the surface barrier height to the metal Fermi energy. For a Wigner-Seitz radius of rsb{s} = 4.1, which is approximately that for which jellium metal is stable, the decay coefficient is precisely 1/4. Over the metallic range of densities rsb{s} = 2-6, the coefficient ranges from 0.195 to 0.274. Thus, if the asymptotic structure of the KS exchange-correlation potential is the image potential, then this structure is due principally to KS exchange effects, the KS correlation contribution being an order of magnitude smaller. These results, then lead to the concept of an 'image' charge localized to the surface region for asymptotic positions of the electron. We have further derived the exact analytical structure in the vacuum of the Slater exchange potential, and of the Pauli-correlation and correlation-kinetic components of the KS exchange potential. These structures are all image-potential-like, decaying respectively as -alphasb{S}(beta)chi,\\ -alphasb{W}(beta)chi and alphasbsp{tsb{c}}{(1)}(beta)/chi. The Pauli-correlation component constitutes the major fraction of the KS exchange potential asymptotically, but there

  9. Three-dimensional potential energy surface of Ar–CO

    Energy Technology Data Exchange (ETDEWEB)

    Sumiyoshi, Yoshihiro, E-mail: y-sumiyoshi@gunma-u.ac.jp [Division of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, 4-2 Aramaki, Maebashi, Gunma 371-8510 (Japan); Endo, Yasuki [Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902 (Japan)

    2015-01-14

    A three-dimensional intermolecular potential energy surface of the Ar–CO complex has been determined by fitting most of the previously reported spectroscopic data, where observed transition frequencies by microwave, millimeter-wave, submillimeter-wave, and infrared spectroscopy were reproduced simultaneously within their experimental accuracies. A free rotor model Hamiltonian considering all the freedom of motions for an atom-diatom system was applied to calculate vibration-rotation energies. A three-dimensional potential energy surface obtained by ab initio calculations at the CCSD(T)-F12b/aug-cc-pV5Z level of theory was parameterized by a model function consisting of 46 parameters. They were used as initial values for the least-squares analysis of the experimental data. A total of 20 parameters were optimized to reproduce all the spectroscopic data.

  10. Electronic structure, molecular bonding and potential energy surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ruedenberg, K. [Ames Laboratory, IA (United States)

    1993-12-01

    By virtue of the universal validity of the generalized Born-Oppenheimer separation, potential energy surfaces (PES`) represent the central conceptual as well as quantitative entities of chemical physics and provide the basis for the understanding of most physicochemical phenomena in many diverse fields. The research in this group deals with the elucidation of general properties of PES` as well as with the quantitative determination of PES` for concrete systems, in particular pertaining to reactions involving carbon, oxygen, nitrogen and hydrogen molecules.

  11. Feet on the potential energy surface, head in the pi clouds

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Quentin [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    This work presents explorations of the potential energy surface of clusters of atoms and of the interactions between molecules. First, structures of small aluminum clusters are examined and classified as ground states, transition states, or higher-order saddle points. Subsequently, the focus shifts to dispersion-dominated π-π interactions when the potential energy surfaces of benzene, substituted benzene, and pyridine dimers are explored. Because DNA nucleotide bases can be thought of as substituted heterocycles, a natural extension of the substituted benzene and pyridine investigations is to model paired nucleotide bases. Finally, the success of the dispersion studies inspires the development of an extension to the computational method used, which will enable the dispersion energy to be modeled – and the potential energy surface explored – in additional chemical systems. The effective fragment potential (EFP) method is described, as well as various quantum mechanical methods. An ab inito quantum mechanical study of 13-atom aluminum clusters is described. EFP studies of aromatic dimers are reported in which dispersion energy makes a significant contribution to the attraction between monomers. Theory and code development toward a means of computing dispersion energy in mixed ab inito-EFP systems are described.

  12. The hibernating 13-lined ground squirrel as a model organism for potential cold storage of platelets

    OpenAIRE

    Cooper, Scott T.; Richters, Karl E.; Melin, Travis E.; Liu, Zhi-Jian; Hordyk, Peter J.; Benrud, Ryan R.; Geiser, Lauren R.; Cash, Steve E.; Simon Shelley, C.; Howard, David R.; Ereth, Mark H.; Sola-Visner, Martha C.

    2012-01-01

    Hibernating mammals have developed many physiological adaptations to extreme environments. During hibernation, 13-lined ground squirrels (Ictidomys tridecemlineatus) must suppress hemostasis to survive prolonged body temperatures of 4–8°C and 3–5 heartbeats per minute without forming lethal clots. Upon arousal in the spring, these ground squirrels must be able to quickly restore normal clotting activity to avoid bleeding. Here we show that ground squirrel platelets stored in vivo at 4–8°C wer...

  13. Theoretical studies of potential energy surfaces and computational methods

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, R. [Argonne National Laboratory, IL (United States)

    1993-12-01

    This project involves the development, implementation, and application of theoretical methods for the calculation and characterization of potential energy surfaces involving molecular species that occur in hydrocarbon combustion. These potential energy surfaces require an accurate and balanced treatment of reactants, intermediates, and products. This difficult challenge is met with general multiconfiguration self-consistent-field (MCSCF) and multireference single- and double-excitation configuration interaction (MRSDCI) methods. In contrast to the more common single-reference electronic structure methods, this approach is capable of describing accurately molecular systems that are highly distorted away from their equilibrium geometries, including reactant, fragment, and transition-state geometries, and of describing regions of the potential surface that are associated with electronic wave functions of widely varying nature. The MCSCF reference wave functions are designed to be sufficiently flexible to describe qualitatively the changes in the electronic structure over the broad range of geometries of interest. The necessary mixing of ionic, covalent, and Rydberg contributions, along with the appropriate treatment of the different electron-spin components (e.g. closed shell, high-spin open-shell, low-spin open shell, radical, diradical, etc.) of the wave functions, are treated correctly at this level. Further treatment of electron correlation effects is included using large scale multireference CI wave functions, particularly including the single and double excitations relative to the MCSCF reference space. This leads to the most flexible and accurate large-scale MRSDCI wave functions that have been used to date in global PES studies.

  14. Potential effects of forest management on surface albedo

    Science.gov (United States)

    Otto, J.; Bréon, F.-M.; Schelhaas, M.-J.; Pinty, B.; Luyssaert, S.

    2012-04-01

    Currently 70% of the world's forests are managed and this figure is likely to rise due to population growth and increasing demand for wood based products. Forest management has been put forward by the Kyoto-Protocol as one of the key instruments in mitigating climate change. For temperate and boreal forests, the effects of forest management on the stand-level carbon balance are reasonably well understood, but the biophysical effects, for example through changes in the albedo, remain elusive. Following a modeling approach, we aim to quantify the variability in albedo that can be attributed to forest management through changes in canopy structure and density. The modelling approach chains three separate models: (1) a forest gap model to describe stand dynamics, (2) a Monte-Carlo model to estimate the probability density function of the optical path length of photons through the canopy and (3) a physically-based canopy transfer model to estimate the interaction between photons and leaves. The forest gap model provides, on a monthly time step the position, height, diameter, crown size and leaf area index of individual trees. The Monte-Carlo model computes from this the probability density function of the distance a photon travels through crown volumes to determine the direct light reaching the forest floor. This information is needed by the canopy transfer model to calculate the effective leaf area index - a quantity that allows it to correctly represent a 3D process with a 1D model. Outgoing radiation is calculated as the result of multiple processes involving the scattering due to the canopy layer and the forest floor. Finally, surface albedo is computed as the ratio between incident solar radiation and calculated outgoing radiation. The study used two time series representing thinning from below of a beech and a Scots pine forest. The results show a strong temporal evolution in albedo during stand establishment followed by a relatively stable albedo once the canopy

  15. Large-aperture ground glass surface profile measurement using coherence scanning interferometry.

    Science.gov (United States)

    Bae, Eundeok; Kim, Yunseok; Park, Sanguk; Kim, Seung-Woo

    2017-01-23

    We present a coherence scanning interferometer configured to deal with rough glass surfaces exhibiting very low reflectance due to severe sub-surface light scattering. A compound light source is prepared by combining a superluminescent light-emitting diode with an ytterbium-doped fiber amplifier. The light source is attuned to offer a short temporal coherence length of 15 μm but with high spatial coherence to secure an adequate correlogram contrast by delivering strongly unbalanced optical power to the low reflectance target. In addition, the infrared spectral range of the light source is shifted close to the visible side at a 1,038 nm center wavelength, so a digital camera of multi-mega pixels available for industrial machine vision can be used to improve the correlogram contrast further with better lateral image resolutions. Experimental results obtained from a ground Zerodur mirror of 200 mm aperture size and 0.9 μm rms roughness are discussed to validate the proposed interferometer system.

  16. Atrazine and its degradation products in surface and ground waters in Zhangjiakou District, China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A method using the solid phase extraction (SPE) and liquid chromatography-mass spectrometry (LC-MS) to analyse atrazine and its degradation products at levels of low nanograms per liter in water has been developed. The environmental water samples were filtered and then extracted by SPE with a new sulfonation of poly(divinylbenzene-co-N- vinylpyrrolidone) sorbents MCX. HPLC/APCIMS was used for the analysis of atrazine and its degradation products, desethylatrazine (DEA), deisopropylatrazine (DIA), didealkylatrazine (DEDIA), and hydroxyatrazine (HYA). The detection limits ranged from 10-50 ng/L in water samples. Samples were collected from deep wells and a reservoir near a plant that produced atrazine. Atrazine concentration levels in most surface samples were above the limit of the China Surface Water Regulation (3 mg/L). In ground water, the levels of degradation product were more than 0.1 mg/L and 5-10 times greater than those of atrazine. The highest DEA concentration in the groundwater sample taken at the 130 m depth was 7.2 ug/L.

  17. Evaluating the potential of IASI ozone observations to constrain simulated surface ozone concentrations

    Directory of Open Access Journals (Sweden)

    G. Foret

    2009-06-01

    Full Text Available A tracer study has been performed for two summers in 2003 and 2004 with a regional chemistry- transport model in order to evaluate the potential constraint that tropospheric ozone observations from nadir viewing infrared sounders like IASI or TES exert on modeled near surface ozone. As these instruments show high sensitivity in the free troposphere, but low sensitivity at ground, our study addresses which amount of this information is transferred to ground through vertical transport processes. Within the European model domain, and within a time span of 4 days, only ozone like tracers initialised in vertical layers above 500 hPa are transported to the surface. For a tracer initialised between 800 and 700 hPa, seven percent reaches the surface within one to three days, when averaging over the whole European model domain, but more than double of it over the Mediterranean sea. These results are confirmed by a second tracer study taking into account averaging kernels related to IASI retrievals.

  18. Ground state analytical ab initio intermolecular potential for the Cl{sub 2}-water system

    Energy Technology Data Exchange (ETDEWEB)

    Hormain, Laureline; Monnerville, Maurice, E-mail: maurice.monnerville@univ-lille1.fr; Toubin, Céline; Duflot, Denis; Pouilly, Brigitte; Briquez, Stéphane [Laboratoire de Physique des Lasers Atomes et Molécules, Unité Mixte de Recherche (UMR) 8523, Université Lille I, Bât. P5, 59655 Villeneuve d’Ascq Cedex (France); Bernal-Uruchurtu, Margarita I.; Hernández-Lamoneda, Ramón [Centro de Investigaciones Químicas, Universidad Autónoma del Estado de Morelos, Cuernavaca 62209, México (Mexico)

    2015-04-14

    The chlorine/water interface is of crucial importance in the context of atmospheric chemistry. Modeling the structure and dynamics at this interface requires an accurate description of the interaction potential energy surfaces. We propose here an analytical intermolecular potential that reproduces the interaction between the Cl{sub 2} molecule and a water molecule. Our functional form is fitted to a set of high level ab initio data using the coupled-cluster single double (triple)/aug-cc-p-VTZ level of electronic structure theory for the Cl{sub 2} − H{sub 2}O complex. The potential fitted to reproduce the three minima structures of 1:1 complex is validated by the comparison of ab initio results of Cl{sub 2} interacting with an increasing number of water molecules. Finally, the model potential is used to study the physisorption of Cl{sub 2} on a perfectly ordered hexagonal ice slab. The calculated adsorption energy, in the range 0.27 eV, shows a good agreement with previous experimental results.

  19. Ground State Energy of the One-Dimensional Discrete Random Schr\\"{o}dinger Operator with Bernoulli Potential

    CERN Document Server

    Bishop, Michael

    2011-01-01

    In this paper, we show the that the ground state energy of the one-dimensional Discrete Random Schr\\"{o}dinger Operator with Bernoulli Potential is controlled asymptotically as the system size N goes to infinity by the random variable, $\\ell_N$ the length the longest consecutive sequence of sites on the lattice with potential equal to zero. Specifically, we will show that with probability one the limit as the system size goes to infinity the ratio of the ground state energy with the energy of a half-sine wave converges to one.

  20. Ozone treatment of coal- and coffee grounds-based active carbons: Water vapor adsorption and surface fractal micropores

    Energy Technology Data Exchange (ETDEWEB)

    Tsunoda, Ryoichi; Ozawa, Takayoshi; Ando, Junichi [Kanagawa Industrial Technology Research Inst., Ebina, Kanagawa (Japan)

    1998-09-15

    Characteristics of the adsorption iostherms of water vapor on active carbons from coal and coffee grounds and those ozonized ones from the surface fractal dimension analysis are discussed. The upswing of the adsorption isotherms in the low relative pressure of coffee grounds-based active carbon, of which isotherms were not scarcely affected on ozonization, was attributed to the adsorption of water molecules on the metallic oxides playing the role of oxygen-surface complexes, which formed the corrugated surfaces on the basal planes of micropore walls with the surface fractal dimension D{sub s} > 2. On the other hand, coal-based active carbon with D{sub s} < 2, which indicated the flat surfaces of micropore walls, showed little effect on the upswing even on ozonization, even though the adsorption amounts of water vapor were increased in the low relative pressure.

  1. Potential energy curves for the ground and low-lying excited states of CuAg

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Davood; Shayesteh, Alireza, E-mail: jamshidi@ccerci.ac.ir, E-mail: ashayesteh@ut.ac.ir [School of Chemistry, College of Science, University of Tehran, 14176 Tehran (Iran, Islamic Republic of); Jamshidi, Zahra, E-mail: jamshidi@ccerci.ac.ir, E-mail: ashayesteh@ut.ac.ir [Chemistry and Chemical Engineering Research Center of Iran, 14335-186 Tehran (Iran, Islamic Republic of)

    2014-10-21

    The ground and low-lying excited states of heteronuclear diatomic CuAg are examined by multi-reference configuration interaction (MRCI) method. Relativistic effects were treated and probed in two steps. Scalar terms were considered using the spin-free DKH Hamiltonian as a priori and spin-orbit coupling was calculated perturbatively via the spin-orbit terms of the Breit-Pauli Hamiltonian based on MRCI wavefunctions. Potential energy curves of the spin-free states and their corresponding Ω components correlating with the separated atom limits {sup 2}S(Cu) + {sup 2}S(Ag) and {sup 2}D(Cu) + {sup 2}S(Ag) are obtained. The results are in fine agreement with the experimental measurements and tentative conclusions for the ion-pair B0{sup +} state are confirmed by our theoretical calculations. Illustrative results are presented to reveal the relative importance and magnitude of the scalar and spin-orbit effects on the spectroscopic properties of this molecule. Time dependent density functional theory calculations, using the LDA, BLYP, B3LYP, and SAOP functionals have been carried out for CuAg and the accuracy of TD-DFT has been compared with ab initio results.

  2. Novel mixture model for the representation of potential energy surfaces

    Science.gov (United States)

    Pham, Tien Lam; Kino, Hiori; Terakura, Kiyoyuki; Miyake, Takashi; Dam, Hieu Chi

    2016-10-01

    We demonstrate that knowledge of chemical physics on a materials system can be automatically extracted from first-principles calculations using a data mining technique; this information can then be utilized to construct a simple empirical atomic potential model. By using unsupervised learning of the generative Gaussian mixture model, physically meaningful patterns of atomic local chemical environments can be detected automatically. Based on the obtained information regarding these atomic patterns, we propose a chemical-structure-dependent linear mixture model for estimating the atomic potential energy. Our experiments show that the proposed mixture model significantly improves the accuracy of the prediction of the potential energy surface for complex systems that possess a large diversity in their local structures.

  3. Potential health impacts from range fires at Aberdeen Proving Ground, Maryland.

    Energy Technology Data Exchange (ETDEWEB)

    Willians, G.P.; Hermes, A.M.; Policastro, A.J.; Hartmann, H.M.; Tomasko, D.

    1998-03-01

    This study uses atmospheric dispersion computer models to evaluate the potential for human health impacts from exposure to contaminants that could be dispersed by fires on the testing ranges at Aberdeen Proving Ground, Maryland. It was designed as a screening study and does not estimate actual human health risks. Considered are five contaminants possibly present in the soil and vegetation from past human activities at APG--lead, arsenic, trichloroethylene (TCE), depleted uranium (DU), and dichlorodiphenyltrichloroethane (DDT); and two chemical warfare agents that could be released from unexploded ordnance rounds heated in a range fire--mustard and phosgene. For comparison, dispersion of two naturally occurring compounds that could be released by burning of uncontaminated vegetation--vinyl acetate and 2-furaldehyde--is also examined. Data from previous studies on soil contamination at APG are used in conjunction with conservative estimates about plant uptake of contaminants, atmospheric conditions, and size and frequency of range fires at APG to estimate dispersion and possible human exposure. The results are compared with US Environmental Protection Agency action levels. The comparisons indicate that for all of the anthropogenic contaminants except arsenic and mustard, exposure levels would be at least an order of magnitude lower than the corresponding action levels. Because of the compoundingly conservative nature of the assumptions made, they conclude that the potential for significant human health risks from range fires is low. The authors recommend that future efforts be directed at fire management and control, rather than at conducting additional studies to more accurately estimate actual human health risk from range fires.

  4. Groundwater Surface Trends at Van Norden Meadow, California, from Ground Penetrating Radar Profiles

    Science.gov (United States)

    Tadrick, N. I.; Blacic, T. M.; Yarnell, S. M.

    2014-12-01

    Van Norden meadow in the Donner Summit area west of Lake Tahoe is one of the largest sub-alpine meadows in the Sierra Nevada mountain range. As natural water retention basins, meadows attenuate floods, improve water quality and support vegetation that stabilizes stream banks and promotes high biodiversity. Like most meadows in the Sierras however, over-grazing, road-building, and development has resulted in localized stream incision, degradation, and partial conversion from wet to dry conditions in Van Norden. Additionally, a small dam at the base of the meadow has partially flooded the lower meadow creating reservoir conditions. Privately owned since the late 1800s, Van Norden was recently purchased by a local land trust to prevent further development and return the area to public ownership. Restoration of the natural meadow conditions will involve notching the dam in 2016 to reduce currently impounded water volumes from 250 to less than 50 acre-feet. To monitor the effects of notching the dam on the upstream meadow conditions, better understanding of the surface and groundwater hydrology both pre- and post-restoration is required. We surveyed the meadow in summer 2014 with ground penetrating radar (GPR) to map the groundwater surface prior to restoration activities using a 270MHz antenna to obtain a suite of longitudinal and transverse transects. Groundwater level within the meadow was assessed using both piezometer readings and sweeps of the GPR antenna. Seventeen piezometers were added this year to the 13 already in place to monitor temporal changes in the groundwater surface, while the GPR profiles provided information about lateral variations. Our results provide an estimate of the groundwater depth variations across the upper portion of the meadow before notching. We plan to return in 2015 to collect GPR profiles during wetter conditions, which will provide a more complete assessment of the pre-notching groundwater hydrology.

  5. Surface Nuclear Magnetic Resonance (SNMR - A new method for exploration of ground water and aquifer properties

    Directory of Open Access Journals (Sweden)

    U. Yaramanci

    2000-06-01

    Full Text Available The Surface Nuclear Magnetic Resonance (SNMR method is a fairly new technique in geophysics to assess ground water, i.e. existence, amount and productibility by measurements at the surface. The NMR technique used in medicine, physics and lately in borehole geophysics was adopted for surface measurements in the early eighties, and commercial equipment for measurements has been available since the mid nineties. The SNMR method has been tested at sites in Northern Germany with Quaternary sand and clay layers, to examine the suitability of this new method for groundwater exploration and environmental investigations. More information is obtained by SNMR, particularly with respect to aquifer parameters, than with other geophysical techniques. SNMR measurements were carried out at three borehole locations, together with 2D and 1D direct current geoelectrics and well logging (induction log, gamma-ray log and pulsed neutron-gamma log. Permeabilities were calculated from the grain-size distributions of core material determined in the laboratory. It is demonstrated that the SNMR method is able to detect groundwater and the results are in good agreement with other geophysical and hydrogeological data. Using the SNMR method, the water content of the unsaturated and saturated zones (i.e. porosity of an aquifer can be reliably determined. This information and resistivity data permit in-situ determination of other aquifer parameters. Comparison of the SNMR results with borehole data clearly shows that the water content determined by SNMR is the free or mobile water in the pores. The permeabilities estimated from the SNMR decay times are similar to those derived from sieve analysis of core material. Thus, the combination of SNMR with geoelectric methods promises to be a powerful tool for studying aquifer properties.

  6. A comparative study of the phosphate levels in some surface and ground water bodies of Swaziland

    Directory of Open Access Journals (Sweden)

    A.O. Fadiran

    2008-08-01

    Full Text Available The levels of total phosphate in selected surface water and groundwater bodies from Manzini and Lubombo regions of Swaziland were determined using UV spectroscopic method. Samples were collected from three rivers (upstream and downstream of each, three industrial effluents, one reservoir, one pond, one tap water and fifteen boreholes. Mean phosphate levels in the tap water and reservoir varied between 0.08-0.09 mg/L while for the river samples, the range was 0.11-0.37 and for the industrial discharge, it was 0.11-1.60 mg/L PO4–P. For the ground water systems it ranged between 0.10-0.49 mg/L PO4–P. The mean phosphate levels in all the analyzed surface and groundwater samples were below the recommended maximum contaminant level (MCL by SWSC (Swaziland Water Service Corporation – i.e. 1.0 mg/L for drinking water; 2.0 mg/L for rivers and industrial effluents, and the South African criterion of 1.0 mg/L PO4–P, for sewage effluents being discharged into receiving waters. However, pooled mean values for all the sites were higher than the USEPA criterion of 0.03 mg/L maximum for uncontaminated lakes. Dominant factors considered to have influenced the levels of phosphates in both the surface and groundwater samples analyzed include industrial activities (where present, agricultural activities (including livestock, population density, location (urban, suburban or rural, soil/rock type in the vicinity of the sampling point, climate and rainfall pattern of the area or region concerned.

  7. Effective medium potentials for molecule-surface interactions: H2 on Cu and Ni surfaces

    DEFF Research Database (Denmark)

    Nørskov, Jens Kehlet

    1989-01-01

    that the functional form of the total energy expression is derived from density functional theory, that each of the terms entering can be given a precise physical interpretation, and that most of the parameters entering can be calculated, within the local density approximation. The method is explicitly derived for H2...... outside metal surfaces and the applicability is illustrated for H2 adsorbing on various Cu and Ni surfaces. Although very approximate, the calculated potentials seem to include a number of features observed experimentally: Ni is more active in dissociating H2 than Cu, and open surfaces are more active...

  8. Questa baseline and pre-mining ground-water quality investigation. 10. Geologic influences on ground and surface waters in the lower Red River watershed, New Mexico

    Science.gov (United States)

    Ludington, Steve; Plumlee, Geoff; Caine, Jonathan; Bove, Dana; Holloway, JoAnn; Livo, Eric

    2005-01-01

    Introduction: This report is one in a series that presents results of an interdisciplinary U.S. Geological Survey (USGS) study of ground-water quality in the lower Red River watershed prior to open-pit and underground molybdenite mining at Molycorp's Questa mine. The stretch of the Red River watershed that extends from just upstream of the town of Red River, N. Mex., to just above the town of Questa includes several mineralized areas in addition to the one mined by Molycorp. Natural erosion and weathering of pyrite-rich rocks in the mineralized areas has created a series of erosional scars along this stretch of the Red River that contribute acidic waters, as well as mineralized alluvial material and sediments, to the river. The overall goal of the USGS study is to infer the premining ground-water quality at the Molycorp mine site. An integrated geologic, hydrologic, and geochemical model for ground water in the mineralized-but unmined-Straight Creek drainage (a tributary of the Red River) is being used as an analog for the geologic, geochemical, and hydrologic conditions that influenced ground-water quality and quantity in the Red River drainage prior to mining. This report provides an overall geologic framework for the Red River watershed between Red River and Questa, in northern New Mexico, and summarizes key geologic, mineralogic, structural and other characteristics of various mineralized areas (and their associated erosional scars and debris fans) that likely influence ground- and surface-water quality and hydrology. The premining nature of the Sulphur Gulch and Goat Hill Gulch scars on the Molycorp mine site can be inferred through geologic comparisons with other unmined scars in the Red River drainage.

  9. A mixed space-time and wavenumber-frequency domain procedure for modelling ground vibration from surface railway tracks

    Science.gov (United States)

    Koroma, S. G.; Thompson, D. J.; Hussein, M. F. M.; Ntotsios, E.

    2017-07-01

    This paper presents a methodology for studying ground vibration in which the railway track is modelled in the space-time domain using the finite element method (FEM) and, for faster computation, discretisation of the ground using either FEM or the boundary element method (BEM) is avoided by modelling it in the wavenumber-frequency domain. The railway track is coupled to the ground through a series of rectangular strips located at the surface of the ground; their vertical interaction is described by a frequency-dependent dynamic stiffness matrix whose elements are represented by discrete lumped parameter models. The effectiveness of this approach is assessed firstly through frequency domain analysis using as excitation a stationary harmonic load applied on the rail. The interaction forces at the ballast/ground interface are calculated using the FE track model in the space-time domain, transformed to the wavenumber domain, and used as input to the ground model for calculating vibration in the free field. Additionally, time domain simulations are also performed with the inclusion of nonlinear track parameters. Results are presented for the coupled track/ground model in terms of time histories and frequency spectra for the track vibration, interaction forces and free-field ground vibration. For the linear track model, the results from the mixed formulation are in excellent agreement with those from a semi-analytical model formulated in the wavenumber-frequency domain, particularly in the vicinity of the loading point. The accuracy of the mixed formulation away from the excitation point depends strongly on the inclusion of through-ground coupling in the lumped parameter model, which has been found to be necessary for both track dynamics and ground vibration predictions.

  10. Ground surface temperature histories in northern Ontario and Québec for the past 500 years

    Science.gov (United States)

    Pickler, Carolyne; Beltrami, Hugo; Mareschal, Jean-Claude

    2016-04-01

    We have used 19 temperature-depth profiles measured in boreholes from eastern Canada to reconstruct the ground surface temperature histories of the region. The boreholes are located north of 51oN, and west and east of James Bay in northern Ontario and Québec. The 8 boreholes in northern Ontario come from 3 sites in a region of extensive discontinuous permafrost, while the 11 holes from Québec come from 6 sites in a region of sporadic discontinuous permafrost. The depths of the holes range between 400 and 800 m, allowing a reconstruction of the ground surface temperature histories for the past 500 years. Present ground surface temperatures are higher in Québec, perhaps because the region receives more snowfall as shown by meteorological records and proxy data. The ground surface temperature histories indicate a present-day warming of ˜2-2.5oC in Ontario and ˜1-1.5oC in Québec relative to the reference surface temperature 500 years BP. These results are in agreement with available proxy data for the recent warming in eastern North America. Furthermore, they suggest that the higher snowfall and strong cooling during the Little Ice Age could have muted the borehole temperature record of climate change in Québec.

  11. An Upscaling Algorithm to Obtain the Representative Ground Truth of LAI Time Series in Heterogeneous Land Surface

    Directory of Open Access Journals (Sweden)

    Yuechan Shi

    2015-09-01

    Full Text Available Upscaling in situ leaf area index (LAI measurements to the footprint scale is important for the validation of medium resolution remote sensing products. However, surface heterogeneity and temporal variation of vegetation make this difficult. In this study, a two-step upscaling algorithm was developed to obtain the representative ground truth of LAI time series in heterogeneous surfaces based on in situ LAI data measured by the wireless sensor network (WSN observation system. Since heterogeneity within a site usually arises from the mixture of vegetation and non-vegetation surfaces, the spatial heterogeneity of vegetation and land cover types were separately considered. Representative LAI time series of vegetation surfaces were obtained by upscaling in situ measurements using an optimal weighted combination method, incorporating the expectation maximum (EM algorithm to derive the weights. The ground truth of LAI over the whole site could then be determined using area weighted combination of representative LAIs of different land cover types. The algorithm was evaluated using a dataset collected in Heihe Watershed Allied Telemetry Experimental Research (HiWater experiment. The proposed algorithm can effectively obtain the representative ground truth of LAI time series in heterogeneous cropland areas. Using the normal method of an average LAI measurement to represent the heterogeneous surface produced a root mean square error (RMSE of 0.69, whereas the proposed algorithm provided RMSE = 0.032 using 23 sampling points. The proposed ground truth derived method was implemented to validate four major LAI products.

  12. Designing of a risk assessment architecture to analyze potential risks from space weather to space and ground based assets

    Science.gov (United States)

    Sattar, Erum

    2016-07-01

    Today's world is more vulnerable to space weather due to ever increased advance and costly space technology deployed in space and on ground. The space weather has a natural potential of posing harmful effects on space and ground based assets and on astronaut's life. This global challenge of space weather essentially demands global and regional preparedness to develop its situational awareness, analyzing risks and devise possible mitigation procedures. Considering risk mitigation architecture as inevitable for all scientific missions, this paper focuses to develop a risk assessment architecture for the space environment and to map its utility in identifying and analyzing potential risks to space and ground based assets from space weather in the South Asia region. Different risk assessment tools will be studied and would conclude in the most effective tool or strategy that may help to develop our capability in identifying, protecting and mitigating from the devastating effects of the space weather.

  13. Simulation of ground-water/surface-water flow in the Santa Clara-Calleguas ground-water basin, Ventura County, California

    Science.gov (United States)

    Hanson, Randall T.; Martin, Peter; Koczot, Kathryn M.

    2003-01-01

    Ground water is the main source of water in the Santa Clara-Calleguas ground-water basin that covers about 310 square miles in Ventura County, California. A steady increase in the demand for surface- and ground-water resources since the late 1800s has resulted in streamflow depletion and ground-water overdraft. This steady increase in water use has resulted in seawater intrusion, inter-aquifer flow, land subsidence, and ground-water contamination. The Santa Clara-Calleguas Basin consists of multiple aquifers that are grouped into upper- and lower-aquifer systems. The upper-aquifer system includes the Shallow, Oxnard, and Mugu aquifers. The lower-aquifer system includes the upper and lower Hueneme, Fox Canyon, and Grimes Canyon aquifers. The layered aquifer systems are each bounded below by regional unconformities that are overlain by extensive basal coarse-grained layers that are the major pathways for ground-water production from wells and related seawater intrusion. The aquifer systems are bounded below and along mountain fronts by consolidated bedrock that forms a relatively impermeable boundary to ground-water flow. Numerous faults act as additional exterior and interior boundaries to ground-water flow. The aquifer systems extend offshore where they crop out along the edge of the submarine shelf and within the coastal submarine canyons. Submarine canyons have dissected these regional aquifers, providing a hydraulic connection to the ocean through the submarine outcrops of the aquifer systems. Coastal landward flow (seawater intrusion) occurs within both the upper- and lower-aquifer systems. A numerical ground-water flow model of the Santa Clara-Calleguas Basin was developed by the U.S. Geological Survey to better define the geohydrologic framework of the regional ground-water flow system and to help analyze the major problems affecting water-resources management of a typical coastal aquifer system. Construction of the Santa Clara-Calleguas Basin model required

  14. Measuring surface flow velocity with smartphones: potential for citizen observatories

    Science.gov (United States)

    Weijs, Steven V.; Chen, Zichong; Brauchli, Tristan; Huwald, Hendrik

    2014-05-01

    Stream flow velocity is an important variable for discharge estimation and research on sediment dynamics. Given the influence of the latter on rating curves (stage-discharge relations), and the relative scarcity of direct streamflow measurements, surface velocity measurements can offer important information for, e.g., flood warning, hydropower, and hydrological science and engineering in general. With the growing amount of sensing and computing power in the hands of more outdoorsy individuals, and the advances in image processing techniques, there is now a tremendous potential to obtain hydrologically relevant data from motivated citizens. This is the main focus of the interdisciplinary "WeSenseIt" project, a citizen observatory of water. In this subproject, we investigate the feasibility of stream flow surface velocity measurements from movie clips taken by (smartphone-) cameras. First results from movie-clip derived velocity information will be shown and compared to reference measurements.

  15. On the Potential Predictability of Seasonal Land-Surface Climate

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, T J

    2001-10-01

    The chaotic behavior of the continental climate of an atmospheric general circulation model is investigated from an ensemble of decadal simulations with common specifications of radiative forcings and monthly ocean boundary conditions, but different initial states of atmosphere and land. The variability structures of key model land-surface processes appear to agree sufficiently with observational estimates to warrant detailed examination of their predictability on seasonal time scales. This predictability is inferred from several novel measures of spatio-temporal reproducibility applied to eleven model variables. The reproducibility statistics are computed for variables in which the seasonal cycle is included or excluded, the former case being most pertinent to climate model simulations, and the latter to predictions of the seasonal anomalies. Because the reproducibility metrics in the latter case are determined in the context of a ''perfectly'' known ocean state, they are properly viewed as estimates of the potential predictability of seasonal climate. Inferences based on these reproducibility metrics are shown to be in general agreement with those derived from more conventional measures of potential predictability. It is found that the land-surface variables which include the seasonal cycle are impacted only marginally by changes in initial conditions; moreover, their seasonal climatologies exhibit high spatial reproducibility. In contrast, the reproducibility of a seasonal land-surface anomaly is generally low, although it is considerably higher in the Tropics; its spatial reproducibility also fluctuates in tandem with warm and cold phases of the El Nino/Southern Oscillation phenomenon. However, the detailed sensitivities to initial conditions depend somewhat on the land-surface process: pressure and temperature anomalies exhibit the highest temporal reproducibilities, while hydrological and turbulent flux anomalies show the highest spatial

  16. Modeling short wave radiation and ground surface temperature: a validation experiment in the Western Alps

    Science.gov (United States)

    Pogliotti, P.; Cremonese, E.; Dallamico, M.; Gruber, S.; Migliavacca, M.; Morra di Cella, U.

    2009-12-01

    Permafrost distribution in high-mountain areas is influenced by topography (micro-climate) and high variability of ground covers conditions. Its monitoring is very difficult due to logistical problems like accessibility, costs, weather conditions and reliability of instrumentation. For these reasons physically-based modeling of surface rock/ground temperatures (GST) is fundamental for the study of mountain permafrost dynamics. With this awareness a 1D version of GEOtop model (www.geotop.org) is tested in several high-mountain sites and its accuracy to reproduce GST and incoming short wave radiation (SWin) is evaluated using independent field measurements. In order to describe the influence of topography, both flat and near-vertical sites with different aspects are considered. Since the validation of SWin is difficult on steep rock faces (due to the lack of direct measures) and validation of GST is difficult on flat sites (due to the presence of snow) the two parameters are validated as independent experiments: SWin only on flat morphologies, GST only on the steep ones. The main purpose is to investigate the effect of: (i) distance between driving meteo station location and simulation point location, (ii) cloudiness, (iii) simulation point aspect, (iv) winter/summer period. The temporal duration of model runs is variable from 3 years for the SWin experiment to 8 years for the validation of GST. The model parameterization is constant and tuned for a common massive bedrock of crystalline rock like granite. Ground temperature profile is not initialized because rock temperature is measured at only 10cm depth. A set of 9 performance measures is used for comparing model predictions and observations (including: fractional mean bias (FB), coefficient of residual mass (CMR), mean absolute error (MAE), modelling efficiency (ME), coefficient of determination (R2)). Results are very encouraging. For both experiments the distance (Km) between location of the driving meteo

  17. Pseudospectral Gaussian quantum dynamics: Efficient sampling of potential energy surfaces

    Science.gov (United States)

    Heaps, Charles W.; Mazziotti, David A.

    2016-04-01

    Trajectory-based Gaussian basis sets have been tremendously successful in describing high-dimensional quantum molecular dynamics. In this paper, we introduce a pseudospectral Gaussian-based method that achieves accurate quantum dynamics using efficient, real-space sampling of the time-dependent basis set. As in other Gaussian basis methods, we begin with a basis set expansion using time-dependent Gaussian basis functions guided by classical mechanics. Unlike other Gaussian methods but characteristic of the pseudospectral and collocation methods, the basis set is tested with N Dirac delta functions, where N is the number of basis functions, rather than using the basis function as test functions. As a result, the integration for matrix elements is reduced to function evaluation. Pseudospectral Gaussian dynamics only requires O ( N ) potential energy calculations, in contrast to O ( N 2 ) evaluations in a variational calculation. The classical trajectories allow small basis sets to sample high-dimensional potentials. Applications are made to diatomic oscillations in a Morse potential and a generalized version of the Henon-Heiles potential in two, four, and six dimensions. Comparisons are drawn to full analytical evaluation of potential energy integrals (variational) and the bra-ket averaged Taylor (BAT) expansion, an O ( N ) approximation used in Gaussian-based dynamics. In all cases, the pseudospectral Gaussian method is competitive with full variational calculations that require a global, analytical, and integrable potential energy surface. Additionally, the BAT breaks down when quantum mechanical coherence is particularly strong (i.e., barrier reflection in the Morse oscillator). The ability to obtain variational accuracy using only the potential energy at discrete points makes the pseudospectral Gaussian method a promising avenue for on-the-fly dynamics, where electronic structure calculations become computationally significant.

  18. Potential Energy Surfaces Using Algebraic Methods Based on Unitary Groups

    Directory of Open Access Journals (Sweden)

    Renato Lemus

    2011-01-01

    Full Text Available This contribution reviews the recent advances to estimate the potential energy surfaces through algebraic methods based on the unitary groups used to describe the molecular vibrational degrees of freedom. The basic idea is to introduce the unitary group approach in the context of the traditional approach, where the Hamiltonian is expanded in terms of coordinates and momenta. In the presentation of this paper, several representative molecular systems that permit to illustrate both the different algebraic approaches as well as the usual problems encountered in the vibrational description in terms of internal coordinates are presented. Methods based on coherent states are also discussed.

  19. Potential Energy Surfaces and Quantum Yields for Photochromic Diarylethene Reactions

    Directory of Open Access Journals (Sweden)

    Makoto Hatakeyama

    2013-05-01

    Full Text Available Photochromic diarylethenes (DAEs are among the most promising molecular switching systems for future molecular electronics. Numerous derivatives have been synthesized recently, and experimental quantum yields (QYs have been reported for two categories of them. Although the QY is one of the most important properties in various applications, it is also the most difficult property to predict before a molecule is actually synthesized. We have previously reported preliminary theoretical studies on what determines the QYs in both categories of DAE derivatives. Here, reflecting theoretical analyses of potential energy surfaces and recent experimental results, a rational explanation of the general guiding principle for QY design is presented for future molecular design.

  20. Taboo search by successive confinement: Surveying a potential energy surface

    Science.gov (United States)

    Chekmarev, Sergei F.

    2001-09-01

    A taboo search for minima on a potential energy surface (PES) is performed by means of confinement molecular dynamics: the molecular dynamics trajectory of the system is successively confined to various basins on the PES that have not been sampled yet. The approach is illustrated for a 13-atom Lennard-Jones cluster. It is shown that the taboo search radically accelerates the process of surveying the PES, with the probability of finding a new minimum defined by a propagating Fermi-like distribution.

  1. Simulation of submillimetre atmospheric spectra for characterising potential ground-based remote sensing observations

    Science.gov (United States)

    Turner, Emma C.; Withington, Stafford; Newnham, David A.; Wadhams, Peter; Jones, Anna E.; Clancy, Robin

    2016-11-01

    The submillimetre is an understudied region of the Earth's atmospheric electromagnetic spectrum. Prior technological gaps and relatively high opacity due to the prevalence of rotational water vapour lines at these wavelengths have slowed progress from a ground-based remote sensing perspective; however, emerging superconducting detector technologies in the fields of astronomy offer the potential to address key atmospheric science challenges with new instrumental methods. A site study, with a focus on the polar regions, is performed to assess theoretical feasibility by simulating the downwelling (zenith angle = 0°) clear-sky submillimetre spectrum from 30 mm (10 GHz) to 150 µm (2000 GHz) at six locations under annual mean, summer, winter, daytime, night-time and low-humidity conditions. Vertical profiles of temperature, pressure and 28 atmospheric gases are constructed by combining radiosonde, meteorological reanalysis and atmospheric chemistry model data. The sensitivity of the simulated spectra to the choice of water vapour continuum model and spectroscopic line database is explored. For the atmospheric trace species hypobromous acid (HOBr), hydrogen bromide (HBr), perhydroxyl radical (HO2) and nitrous oxide (N2O) the emission lines producing the largest change in brightness temperature are identified. Signal strengths, centre frequencies, bandwidths, estimated minimum integration times and maximum receiver noise temperatures are determined for all cases. HOBr, HBr and HO2 produce brightness temperature peaks in the mK to µK range, whereas the N2O peaks are in the K range. The optimal submillimetre remote sensing lines for the four species are shown to vary significantly between location and scenario, strengthening the case for future hyperspectral instruments that measure over a broad wavelength range. The techniques presented here provide a framework that can be applied to additional species of interest and taken forward to simulate retrievals and guide the

  2. Accurate global potential energy surface for the H + OH+ collision

    Science.gov (United States)

    Gannouni, M. A.; Jaidane, N. E.; Halvick, P.; Stoecklin, T.; Hochlaf, M.

    2014-05-01

    We mapped the global three-dimensional potential energy surface (3D-PES) of the water cation at the MRCI/aug-cc-pV5Z including the basis set superposition (BSSE) correction. This PES covers the molecular region and the long ranges close to the H + OH+(X3Σ-), the O + H2+(X2Σg+), and the hydrogen exchange channels. The quality of the PES is checked after comparison to previous experimental and theoretical results of the spectroscopic constants of H2O+(tilde X2B1) and of the diatomic fragments, the vibronic spectrum, the dissociation energy, and the barrier to linearity for H2O+(tilde X2B1). Our data nicely approach those measured and computed previously. The long range parts reproduce quite well the diatomic potentials. In whole, a good agreement is found, which validates our 3D-PES.

  3. Simple realization of inflaton potential on a Riemann surface

    Directory of Open Access Journals (Sweden)

    Keisuke Harigaya

    2014-11-01

    Full Text Available The observation of the B-mode in the cosmic microwave background radiation combined with the so-called Lyth bound suggests the trans-Planckian variation of the inflaton field during inflation. Such a large variation generates concerns over inflation models in terms of the effective field theory below the Planck scale. If the inflaton resides in a Riemann surface and the inflaton potential is a multivalued function of the inflaton field when it is viewed as a function on a complex plane, the Lyth bound can be satisfied while keeping field values in the effective field theory within the Planck scale. We show that a multivalued inflaton potential can be realized starting from a single-valued Lagrangian of the effective field theory below the Planck scale.

  4. Urban archaeological investigations using surface 3D Ground Penetrating Radar and Electrical Resistivity Tomography methods

    Science.gov (United States)

    Papadopoulos, Nikos; Sarris, Apostolos; Yi, Myeong-Jong; Kim, Jung-Ho

    2009-02-01

    Ongoing and extensive urbanisation, which is frequently accompanied with careless construction works, may threaten important archaeological structures that are still buried in the urban areas. Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT) methods are most promising alternatives for resolving buried archaeological structures in urban territories. In this work, three case studies are presented, each of which involves an integrated geophysical survey employing the surface three-dimensional (3D) ERT and GPR techniques, in order to archaeologically characterise the investigated areas. The test field sites are located at the historical centres of two of the most populated cities of the island of Crete, in Greece. The ERT and GPR data were collected along a dense network of parallel profiles. The subsurface resistivity structure was reconstructed by processing the apparent resistivity data with a 3D inversion algorithm. The GPR sections were processed with a systematic way, applying specific filters to the data in order to enhance their information content. Finally, horizontal depth slices representing the 3D variation of the physical properties were created. The GPR and ERT images significantly contributed in reconstructing the complex subsurface properties in these urban areas. Strong GPR reflections and high-resistivity anomalies were correlated with possible archaeological structures. Subsequent excavations in specific places at both sites verified the geophysical results. The specific case studies demonstrated the applicability of ERT and GPR techniques during the design and construction stages of urban infrastructure works, indicating areas of archaeological significance and guiding archaeological excavations before construction work.

  5. The impact of municipal landfill on surface and ground water quality in Bulawayo, Zimbabwe

    Directory of Open Access Journals (Sweden)

    R. Nyengera

    2012-11-01

    Full Text Available Leachate from Richmond municipal landfill, underlain by the Matsheumhlope unconfined aquifer in Bulawayo city and its consequent water resource quality impacts are evaluated. Leachate samples from collection ponds and water samples from a stream, and up and down-gradient boreholes fromthe landfill were tested for nine pollutants. The leachate pollutants found in both surface and ground water included metals (Fe, Pb and Hg and organic compounds that are hazardous to both human and the environmental health. Borehole water quality compliance with the relevant national and international regulations is reported. From borehole water samples, only chloride and nitrate with concentrations of 56.9 mg/ℓ and 2.26 mg/ℓ, respectively, were within the World Health Organisation (WHO recommended limits for drinking water of 250 mg/ℓ and 10 mg/ℓ, respectively. Lead and mercury concentrations of 0.22 mg/ℓ and 0.04 mg/ℓ were 10 times higher than WHO guidelines of 0.01 and 0.001 mg/ℓ, respectively. Both landfill and informal settlement activities near the landfill impact negatively to water resources quality in the area. City council should minimize waste by recycling, pre-treat collected leachate and drill monitoring wells around the landfill to check possible leachate leaks to water resources and take remedial actions, such assubmerged leachate combustion and evaporation.

  6. A study of the efficiency of spur gears made of powder metallurgy materials - ground versus super-finished surfaces

    OpenAIRE

    Li, Xinmin; Sosa, Mario; Andersson, Martin; Olofsson, Ulf

    2016-01-01

    Power loss is one of the main concerns in gear transmission systems. In this study a recirculating power back-to-back FZG test rig was used to investigate the efficiency of spur gears made of powder metallurgy (PM) material using two different surface manufacturing methods (ground and super-finished). The results were compared with previously presented results of standard gear material from the same test rig. The influence of the material (Wrought steel or PM) and surface roughness on the gea...

  7. Lithium content in potable water, surface water, ground water, and mineral water on the territory of Republic of Macedonia

    OpenAIRE

    Vesna Kostik; Biljana Bauer; Zoran Kavrakovski

    2014-01-01

    The aim of this study was to determine lithium concentration in potable water, surface water, ground, and mineral water on the territory of the Republic of Macedonia. Water samples were collected from water bodies such as multiple public water supply systems located in 13 cities, wells boreholes located in 12 areas, lakes and rivers located in three different areas. Determination of lithium concentration in potable water, surface water was performed by the technique of inductively coupl...

  8. Informing hydrological models with ground-based time-lapse relative gravimetry: potential and limitations

    DEFF Research Database (Denmark)

    Bauer-Gottwein, Peter; Christiansen, Lars; Rosbjerg, Dan

    2011-01-01

    Coupled hydrogeophysical inversion emerges as an attractive option to improve the calibration and predictive capability of hydrological models. Recently, ground-based time-lapse relative gravity (TLRG) measurements have attracted increasing interest because there is a direct relationship between ...

  9. Use of chemical and isotopic tracers to characterize the interactions between ground water and surface water in mantled karst

    Science.gov (United States)

    Katz, B.G.; Coplen, T.B.; Bullen, T.D.; Hal, Davis J.

    1997-01-01

    In the mantled karst terrane of northern Florida, the water quality of the Upper Floridan aquifer is influenced by the degree of connectivity between the aquifer and the surface. Chemical and isotopic analyses [18O/16O (??18O), 2H/1H (??D), 13C/12C (??13C), tritium(3H), and strontium-87/strontium-86(87Sr/86Sr)]along with geochemical mass-balance modeling were used to identify the dominant hydrochemical processes that control the composition of ground water as it evolves downgradient in two systems. In one system, surface water enters the Upper Floridan aquifer through a sinkhole located in the Northern Highlands physiographic unit. In the other system, surface water enters the aquifer through a sinkhole lake (Lake Bradford) in the Woodville Karst Plain. Differences in the composition of water isotopes (??18O and ??D) in rainfall, ground water, and surface water were used to develop mixing models of surface water (leakage of water to the Upper Floridan aquifer from a sinkhole lake and a sinkhole) and ground water. Using mass-balance calculations, based on differences in ??18O and ??D, the proportion of lake water that mixed with meteoric water ranged from 7 to 86% in water from wells located in close proximity to Lake Bradford. In deeper parts of the Upper Floridan aquifer, water enriched in 18O and D from five of 12 sampled municipal wells indicated that recharge from a sinkhole (1 to 24%) and surface water with an evaporated isotopic signature (2 to 32%) was mixing with ground water. The solute isotopes, ??13C and 87Sr/86Sr, were used to test the sensitivity of binary and ternary mixing models, and to estimate the amount of mass transfer of carbon and other dissolved species in geochemical reactions. In ground water downgradient from Lake Bradford, the dominant processes controlling carbon cycling in ground water were dissolution of carbonate minerals, aerobic degradation of organic matter, and hydrolysis of silicate minerals. In the deeper parts of the Upper

  10. Using distributed temperature sensing to monitor field scale dynamics of ground surface temperature and related substrate heat flux

    NARCIS (Netherlands)

    Bense, V.F.; Read, T.; Verhoef, A.

    2016-01-01

    We present one of the first studies of the use of distributed temperature sensing (DTS) along fibre-optic cables to purposely monitor spatial and temporal variations in ground surface temperature (GST) and soil temperature, and provide an estimate of the heat flux at the base of the canopy layer

  11. Permutation invariant polynomial neural network approach to fitting potential energy surfaces. III. Molecule-surface interactions

    Science.gov (United States)

    Jiang, Bin; Guo, Hua

    2014-07-01

    The permutation invariant polynomial-neural network (PIP-NN) method for constructing highly accurate potential energy surfaces (PESs) for gas phase molecules is extended to molecule-surface interaction PESs. The symmetry adaptation in the NN fitting of a PES is achieved by employing as the input symmetry functions that fulfill both the translational symmetry of the surface and permutation symmetry of the molecule. These symmetry functions are low-order PIPs of the primitive symmetry functions containing the surface periodic symmetry. It is stressed that permutationally invariant cross terms are needed to avoid oversymmetrization. The accuracy and efficiency are demonstrated in fitting both a model PES for the H2 + Cu(111) system and density functional theory points for the H2 + Ag(111) system.

  12. Delta self-consistent field method to obtain potential energy surfaces of excited molecules on surfaces

    DEFF Research Database (Denmark)

    Gavnholt, Jeppe; Olsen, Thomas; Engelund, Mads;

    2008-01-01

    We present a modification of the Delta self-consistent field (Delta SCF) method of calculating energies of excited states in order to make it applicable to resonance calculations of molecules adsorbed on metal surfaces, where the molecular orbitals are highly hybridized. The Delta SCF approximation...... is a density-functional method closely resembling standard density-functional theory (DFT), the only difference being that in Delta SCF one or more electrons are placed in higher lying Kohn-Sham orbitals instead of placing all electrons in the lowest possible orbitals as one does when calculating the ground......-state energy within standard DFT. We extend the Delta SCF method by allowing excited electrons to occupy orbitals which are linear combinations of Kohn-Sham orbitals. With this extra freedom it is possible to place charge locally on adsorbed molecules in the calculations, such that resonance energies can...

  13. Effects of surface applications of biosolids on soil, crops, ground water, and streambed sediment near Deer Trail, Colorado, 1999-2003

    Science.gov (United States)

    Yager, Tracy J.B.; Smith, David B.; Crock, James G.

    2004-01-01

    The U.S. Geological Survey, in cooperation with Metro Wastewater Reclamation District and North Kiowa Bijou Groundwater Management District, studied natural geochemical effects and the effects of biosolids applications to the Metro Wastewater Reclamation District properties near Deer Trail, Colorado, during 1999 through 2003 because of public concern about potential contamination of soil, crops, ground water, and surface water from biosolids applications. Parameters analyzed for each monitoring component included arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc (the nine trace elements regulated by Colorado for biosolids), gross alpha and gross beta radioactivity, and plutonium, as well as other parameters. Concentrations of the nine regulated trace elements in biosolids were relatively uniform and did not exceed applicable regulatory standards. All plutonium concentrations in biosolids were below the minimum detectable level and were near zero. The most soluble elements in biosolids were arsenic, molybdenum, nickel, phosphorus, and selenium. Elevated concentrations of bismuth, mercury, phosphorus, and silver would be the most likely inorganic biosolids signature to indicate that soil or streambed sediment has been affected by biosolids. Molybdenum and tungsten, and to a lesser degree antimony, cadmium, cobalt, copper, mercury, nickel, phosphorus, and selenium, would be the most likely inorganic 'biosolids signature' to indicate ground water or surface water has been affected by biosolids. Soil data indicate that biosolids have had no measurable effect on the concentration of the constituents monitored. Arsenic concentrations in soil of both Arapahoe and Elbert County monitoring sites (like soil from all parts of Colorado) exceed the Colorado soil remediation objectives and soil cleanup standards, which were determined by back-calculating a soil concentration equivalent to a one-in-a-million cumulative cancer risk. Lead concentrations

  14. Implementing ground surface deformation tools to characterize field-scale properties of a fractured aquifer during a short hydraulic test

    Science.gov (United States)

    Schuite, Jonathan; Longuevergne, Laurent; Bour, Olivier; Boudin, Frédérick; Durand, Stéphane

    2016-04-01

    In naturally fractured reservoirs, fluid flow is governed by the structural and hydromechanical properties of fracture networks or conductive fault zones. In order to ensure a sustained exploitation of resources or to assess the safety of underground storage, it is necessary to evaluate these properties. As they generally form highly heterogeneous and anisotropic reservoirs, fractured media may be well characterized by means of several complementary experimental methods or sounding techniques. In this framework, the observation of ground deformation has been proved useful to gain insight of a fractured reservoir's geometry and hydraulic properties. Commonly, large conductive structures like faults can be studied from surface deformation from satellite methods at monthly time scales, whereas meter scale fractures have to be examined under short-term in situ experiments using high accuracy intruments like tiltmeters or extensometers installed in boreholes or at the ground's surface. To the best of our knowledge, the feasability of a field scale (~ 100 m) characterization of a fractured reservoir with geodetic tools in a short term experiment has not yet been addressed. In the present study, we implement two complementary ground surface geodetic tools, namely tiltmetry and optical leveling, to monitor the deformation induced by a hydraulic recovery test at the Ploemeur hydrological observatory (France). Employing a simple purely elastic modeling approach, we show that the joint use of time constraining data (tilt) and spatially constraining data (vertical displacement) makes it possible to evaluate the geometry (dip, root depth and lateral extent) and the storativity of a hydraulically active fault zone, in good agreement with previous studies. Hence we demonstrate that the adequate use of two complementary ground surface deformation methods offer a rich insight of large conductive structure's properties using a single short term hydraulic load. Ground surface

  15. On the wettability diversity of C/SiC surface: Comparison of the ground C/SiC surface and ablated C/SiC surface from three aspects

    Science.gov (United States)

    Wu, M. L.; Ren, C. Z.; Xu, H. Z.

    2016-11-01

    The coefficient of thermal conductivity was influenced by the wetting state of material. The wetting state usually depends on the surface wettability. C/SiC is a promising ceramic composites with multi-components. The wettability of C/SiC composites is hard to resort to the classical wetting theory directly. So far, few investigations focused on C/SiC surface wettability diversity after different material removal processes. In this investigation, comparative studies of surface wettability of ground C/SiC surface and laser-ablated C/SiC surface were carried out through apparent contact angle (APCA) measurements. The results showed that water droplets easily reached stable state on ground C/SiC surface; while the water droplets rappidly penetrated into the laser-ablated C/SiC surface. In order to find out the reason for wettability distinctions between the ground C/SiC surface and the laser-ablated C/SiC surface, comparative studies on the surface micro-structure, surface C-O-Si distribution, and surface C-O-Si weight percentage were carried out. The results showed that (1) A large number of micro cracks in the fuzzy pattern layer over laser-ablated C/SiC surfaces easily destoried the surface tension of water droplets, while only a few cracks existed over the ground C/SiC surfaces. (2) Chemical components (C, O, Si) were non-uniformly distributed on ground C/SiC surfaces, while the chemical components (C, O, Si) were uniformly distributed on laser-ablated C/SiC surfaces. (3) The carbon weight percentage on ground C/SiC surfaces were higher than that on laser-ablated C/SiC surfaces. All these made an essential contribution to the surface wettability diversity of C/SiC surface. Although more investigations about the quantitative influence of surface topography and surface chemical composition on composites wettability are still needed, the conslusion can be used in application: the wettability of C/SiC surface can be controlled by different material removal process

  16. Ground-water potentialities in the Crescent Valley, Eureka and Lander Counties, Nevada

    Science.gov (United States)

    Zones, Christie Paul

    1961-01-01

    pumpage from wells in the valley was 2,300 acre-feet. The Crescent Valley is a basin in which has accumulated a large volume of sediments that had been eroded and transported by streams from the surrounding mountains. The deepest wells have penetrated only the upper 350 feet of these sediments, which on the basis of the known thickness of sediments in other intermontane basins in central Nevada may be as much as several thousand feet thick. Because this valley fill is saturated practically to the level of the valley floor, the total volume of ground water in storage amounts to millions of acre-feet. In practically all wells drilled to date, the water has been of a quality satisfactory for irrigation and domestic use. The amount of water that can be developed and used perennially is far smaller than the total in storage and is dependent upon the average annual recharge to the ground-water reservoir. This recharge comes principally from streams, fed largely by snowmelt, that drain the higher mountains. The average annum recharge to the valley fill is estimated to be about 13,000 acre-feet. This natural supply, which is largely consumed by native vegetation on the valley floor, constitutes a perennial supply for beneficial use only to the extent that the natural discharge can be reduced. In time, much of the natural discharge, can probably be salvaged, if it is economically feasible to pump ground water after water levels have been lowered as much as 100 feet in the areas that now appear to be favorable for the development of irrigation supplies. In 5 wells in the phreatophyte area, where the water table is within 3-8 feet of the land surface, the trends in water level have paralleled those, in precipitation-downward during the dry years 1952-55, upward in wetter 1956 and 1957, and as high in 1957 as at any time since 1948. In most wells there is also a seasonal fluctuation of 1-3 feet, from a high in the spring to a low in the fall. There is no evi

  17. Surface-wave potential for triggering tectonic (nonvolcanic) tremor

    Science.gov (United States)

    Hill, D.P.

    2010-01-01

    Source processes commonly posed to explain instances of remote dynamic triggering of tectonic (nonvolcanic) tremor by surface waves include frictional failure and various modes of fluid activation. The relative potential for Love- and Rayleigh-wave dynamic stresses to trigger tectonic tremor through failure on critically stressed thrust and vertical strike-slip faults under the Coulomb-Griffith failure criteria as a function of incidence angle is anticorrelated over the 15- to 30-km-depth range that hosts tectonic tremor. Love-wave potential is high for strike-parallel incidence on low-angle reverse faults and null for strike-normal incidence; the opposite holds for Rayleigh waves. Love-wave potential is high for both strike-parallel and strike-normal incidence on vertical, strike-slip faults and minimal for ~45?? incidence angles. The opposite holds for Rayleigh waves. This pattern is consistent with documented instances of tremor triggered by Love waves incident on the Cascadia mega-thrust and the San Andreas fault (SAF) in central California resulting from shear failure on weak faults (apparent friction, ????? 0.2). However, documented instances of tremor triggered by surface waves with strike-parallel incidence along the Nankai megathrust beneath Shikoku, Japan, is associated primarily with Rayleigh waves. This is consistent with the tremor bursts resulting from mixed-mode failure (crack opening and shear failure) facilitated by near-lithostatic ambient pore pressure, low differential stress, with a moderate friction coefficient (?? ~ 0.6) on the Nankai subduction interface. Rayleigh-wave dilatational stress is relatively weak at tectonic tremor source depths and seems unlikely to contribute significantly to the triggering process, except perhaps for an indirect role on the SAF in sustaining tremor into the Rayleigh-wave coda that was initially triggered by Love waves.

  18. Impact of the variability of the seasonal snow cover on the ground surface regimes in Hurd Peninsula (Livingston Island, Antarctic)

    Science.gov (United States)

    Nieuwendam, Alexandre; Ramos, Miguel; Vieira, Gonçalo

    2014-05-01

    Seasonally snow cover has a great impact on the thermal regime of the active layer and permafrost. Ground temperatures over a year are strongly affected by the timing, duration, thickness, structure and physical and thermal properties of snow cover. The purpose of this communication is to characterize the shallow ground thermal regimes, with special reference to the understanding of the influence snow cover in permafrost spatial distribution, in the ice-free areas of the north western part of Hurd Peninsula in the vicinity of the Spanish Antarctic Station "Juan Carlos I" and Bulgarian Antarctic Station "St. Kliment Ohridski". We have analyzed and ground temperatures as well as snow thickness data in four sites distributed along an altitudinal transect in Hurd Peninsula from 2007 to 2013: Nuevo Incinerador (25 m asl), Collado Ramos (110 m), Ohridski (140 m) and Reina Sofia Peak (275 m). At each study site, data loggers were installed for the monitoring of air temperatures (at 1.5 m high), ground temperatures (5, 20 and 40 cm depth) and for snow depth (2, 5, 10, 20, 40, 80 and 160 cm) at 4-hour intervals. The winter data suggests the existence of three types of seasonal stages regarding the ground surface thermal regime and the thickness of snow cover: (a) shallow snow cover with intense ground temperatures oscillations; (b) thick snow cover and low variations of soil temperatures; and (c) stability of ground temperatures. Ground thermal conditions are also conditioned by a strong variability. Winter data indicates that Nuevo Incinerador site experiences more often thicker snow cover with higher ground temperatures and absence of ground temperatures oscillations. Collado Ramos and Ohridski show frequent variations of snow cover thickness, alternating between shallow snow cover with high ground temperature fluctuation and thick snow cover and low ground temperature fluctuation. Reina Sofia in all the years has thick snow cover with little variations in soil

  19. The hibernating 13-lined ground squirrel as a model organism for potential cold storage of platelets.

    Science.gov (United States)

    Cooper, Scott T; Richters, Karl E; Melin, Travis E; Liu, Zhi-jian; Hordyk, Peter J; Benrud, Ryan R; Geiser, Lauren R; Cash, Steve E; Simon Shelley, C; Howard, David R; Ereth, Mark H; Sola-Visner, Martha C

    2012-05-15

    Hibernating mammals have developed many physiological adaptations to extreme environments. During hibernation, 13-lined ground squirrels (Ictidomys tridecemlineatus) must suppress hemostasis to survive prolonged body temperatures of 4-8°C and 3-5 heartbeats per minute without forming lethal clots. Upon arousal in the spring, these ground squirrels must be able to quickly restore normal clotting activity to avoid bleeding. Here we show that ground squirrel platelets stored in vivo at 4-8°C were released back into the blood within 2 h of arousal in the spring with a body temperature of 37°C but were not rapidly cleared from circulation. These released platelets were capable of forming stable clots and remained in circulation for at least 2 days before newly synthesized platelets were detected. Transfusion of autologous platelets stored at 4°C or 37°C showed the same clearance rates in ground squirrels, whereas rat platelets stored in the cold had a 140-fold increase in clearance rate. Our results demonstrate that ground squirrel platelets appear to be resistant to the platelet cold storage lesions observed in other mammals, allowing prolonged storage in cold stasis and preventing rapid clearance upon spring arousal. Elucidating these adaptations could lead to the development of methods to store human platelets in the cold, extending their shelf life.

  20. Application of terrestrial laser scanning for detection of ground surface deformation in small mud volcano (Murono, Japan)

    Science.gov (United States)

    Hayakawa, Yuichi S.; Kusumoto, Shigekazu; Matta, Nobuhisa

    2016-07-01

    We perform terrestrial laser scanning (TLS) to detect changes in surface morphology of a mud volcano in Murono, north-central Japan. The study site underwent significant deformation by a strong earthquake in 2011, and the surface deformation has continued in the following years. The point cloud datasets were obtained by TLS at three different times in 2011, 2013 and 2014. Those point clouds were aligned by cloud-based registration, which minimizes the closest point distance of point clouds of unchanged ground features, and the TLS-based point cloud data appear to be suitable for detecting centimeter-order deformations in the central domain of the mud volcano, as well as for measurements of topographic features including cracks of paved ground surface. The spatial patterns and accumulative amount of the vertical deformation during 2011-2014 captured by TLS correspond well with those previously reported based on point-based leveling surveys, supporting the validity of TLS survey.

  1. Understanding the Potential of Aeroelastic Couplings to Stabilize Ground and Air Resonance in a Soft-Inplane Tiltrotor

    Science.gov (United States)

    Howard, Anna K. T.

    1999-01-01

    The tiltrotor offers the best mix of hovering and cruise flight of any of the current V/STOL configurations. One possible improvement on the tiltrotors of today designs would be using a soft-inplane hingeless hub. The advantages to a soft-inplane hingeless hub range from reduced weight and maintenance to reduced vibration and loads. However, soft-inplane rotor systems are inherently in danger of the aeromechanical instabilities of ground and air resonance. Furthermore tiltrotors can be subject to whirl flutter. At least in part because of the potential for air and ground resonance in a soft-inplane rotor, the Bell XV-15, the Bell-Boeing V-22 Osprey, and the new Bell Augusta 609 have stiff-inplane, gimballed rotors which do not experience these instabilities. In order to design soft-inplane V/STOL aircraft that do not experience ground or air resonance, it is important to be able to predict these instabilities accurately. Much of the research studying the stability of tiltrotors has been focused on the understanding and prediction of whirl flutter. As this instability is increasingly well understood, air and ground resonance for a tiltrotor need to be investigated. Once we understand the problems of air and ground resonance in a tiltrotor, we must look for solutions to these instabilities. Other researchers have found composite or kinematic couplings in the blades of a helicopter helpful for ground and air resonance stability. Tiltrotor research has shown composite couplings in the wing to be helpful for whirl flutter. Therefore, this project will undertake to model ground and air resonance of a soft-inplane hingeless tiltrotor to understand the mechanisms involved and to evaluate whether aeroelastic couplings in the wing or kinematic couplings in the blades would aid in stabilizing these instabilities in a tiltrotor.

  2. Calculation of Electric Field at Ground Surface and ADSS Cable Prepared Hanging Point near EHV Power Transmission Tower

    Directory of Open Access Journals (Sweden)

    Xu Bao-Qing

    2016-01-01

    Full Text Available A simplified model of the 750kV tower is established by CDEGS software which is based on the Method Of Moment. The power frequency electric field distribution on the ground is achieved by software calculation and field-measuring. The validity of the calculation is proved when compare the calculation and experiment results. The model also can be used to calculate the electric field in prepared hanging points on the tower. Results show that the electric field distribution on the ground surface around the tower and prepared hanging points are meet the standard by calculation and experiment.

  3. Near-surface geothermal potential assessment of the region Leogang - Saalbach-Hinterglemm in Salzburg, Austria

    Science.gov (United States)

    Bottig, Magdalena; Rupprecht, Doris; Hoyer, Stefan

    2017-04-01

    Within the EU-funded Alpine Space project GRETA (Near-surface Geothermal Resources in the Territory of the Alpine space), a potential assessment for the use of near-surface geothermal energy is being performed. The focus region for Austria is represented by the two communities Leogang and Saalbach-Hinterglemm where settlements are located in altitudes of about 800 - 1.000 m. In these communities, as well as in large parts of the alpine space region in Austria, winter sports tourism is an important economic factor. The demand for heating and domestic hot water in this region of about 6.000 inhabitants rises significantly in the winter months due to around 2 million guest nights per year. This makes clear why the focus is on touristic infrastructure like alpine huts or hotels. It is a high-altitude area with a large number of remote houses, thus district-heating is not ubiquitous - thus, near-surface geothermal energy can be a useful solution for a self-sufficient energy supply. The objective of detailed investigation within the project is, to which extent the elevation, the gradient and the orientation of the hillside influence the geothermal usability of the shallow underground. To predict temperatures in depths of up to 100 m and therefore make statements on the geothermal usability of a certain piece of land, it is necessary to attain a precise ground-temperature map which reflects the upper model boundary. As there are no ground temperature measurement stations within the region, the GBA has installed four monitoring stations. Two are located in the valley, at altitudes of about 800 m, and two in higher altitudes of about 1.200 m, one on a south- and one on a north-slope. Using a software invented by the University of Soil Sciences in Vienna a ground-temperature map will be calculated. The calculation is based on climatic data considering parameters like soil composition. Measured values from the installed monitoring stations will help to validate or to

  4. Geophysical Monitoring of Ground Surface Deformation Associated with a Confined Aquifer Storage and Recovery Operation

    Science.gov (United States)

    Bonneville, Alain; Heggy, Essam; Strickland, Christopher; Normand, Jonathan; Dermond, Jeffrey; Fang, Yilin; Sullivan, Charlotte

    2015-08-01

    One important issue in the storage of large volumes of fluids, mainly water and CO2, in the deep subsurface is to determine the resulting field-scale-induced displacements and consequences of overpressures on the mechanical integrity of the storage reservoir and surroundings. A quantifiable estimation of displacement can be made by combining the robust, cost-effective, and repeatable geophysical techniques of micro-gravimetry, differential global positioning system (DGPS), and differential synthetic aperture radar interferometry (DInSAR). These techniques were field tested and evaluated for the first time on an active large-volume aquifer storage and recovery (ASR) project in Pendleton, Oregon, USA, where three ASR wells are injecting up to 1.9 million m3 year-1 into basalt aquifers to a depth of about 150 m. Injection and recovery of water at the wells are accompanied by significant gravity anomalies and vertical deformation of the ground surface localized to the immediate surroundings of the injection wells as evidenced by DGPS and gravity measurements collected in 2011. At a larger scale, and between 2011 and 2013, DInSAR monitoring of the Pendleton area shows sub- centimetric deformation in the western part of the city and close to the injection locations associated with ASR cycle. Deformations are found to be temporally out phased with the injection and recovery events due to complex groundwater flow. A numerical simulation of the effect of the water injection gives results in good agreement with the observations and confirms the validity of the approach, which could be deployed in similar geological contexts to look at the mechanical effects of water and gas injections.

  5. Analysis of the Effects of Vitiates on Surface Heat Flux in Ground Tests of Hypersonic Vehicles

    Science.gov (United States)

    Cuda, Vincent; Gaffney, Richard L

    2008-01-01

    To achieve the high enthalpy conditions associated with hypersonic flight, many ground test facilities burn fuel in the air upstream of the test chamber. Unfortunately, the products of combustion contaminate the test gas and alter gas properties and the heat fluxes associated with aerodynamic heating. The difference in the heating rates between clean air and a vitiated test medium needs to be understood so that the thermal management system for hypersonic vehicles can be properly designed. This is particularly important for advanced hypersonic vehicle concepts powered by air-breathing propulsion systems that couple cooling requirements, fuel flow rates, and combustor performance by flowing fuel through sub-surface cooling passages to cool engine components and preheat the fuel prior to combustion. An analytical investigation was performed comparing clean air to a gas vitiated with methane/oxygen combustion products to determine if variations in gas properties contributed to changes in predicted heat flux. This investigation started with simple relationships, evolved into writing an engineering-level code, and ended with running a series of CFD cases. It was noted that it is not possible to simultaneously match all of the gas properties between clean and vitiated test gases. A study was then conducted selecting various combinations of freestream properties for a vitiated test gas that matched clean air values to determine which combination of parameters affected the computed heat transfer the least. The best combination of properties to match was the free-stream total sensible enthalpy, dynamic pressure, and either the velocity or Mach number. This combination yielded only a 2% difference in heating. Other combinations showed departures of up to 10% in the heat flux estimate.

  6. Ab initio characterization of low-lying triplet state potential-energy surfaces and vibrational frequencies in the Wulf band of ozone

    Science.gov (United States)

    Xie, Daiqian; Guo, Hua; Peterson, Kirk A.

    2001-12-01

    Accurate ab initio potential-energy surfaces of the 3A2 and 3B1 states of ozone and their nonadiabatic coupling are reported near the ground-state equilibrium geometry using an internally contracted multireference configuration interaction method. These coupled three-dimensional potential-energy surfaces enable the first theoretical characterization of all three vibrational modes in the Wulf band. Reasonably good agreement with recent experimental observations is obtained.

  7. Topographic reference points in California for the regional ground-water potential map by Bedinger and Harrill (2004), Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set is a compilation of reference points representing surface-water features, ground-water levels, and topographic settings in California that...

  8. Topographic reference points in California for the regional ground-water potential map by Bedinger and Harrill (2004), Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set is a compilation of reference points representing surface-water features, ground-water levels, and topographic settings in California that were...

  9. Topographic reference points in Nevada for the regional ground-water potential map by Bedinger and Harrill (2004), Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set is a compilation of reference points representing surface-water features, ground-water levels, and topographic settings in Nevada that were...

  10. Improved DFT Potential Energy Surfaces via Improved Densities.

    Science.gov (United States)

    Kim, Min-Cheol; Park, Hansol; Son, Suyeon; Sim, Eunji; Burke, Kieron

    2015-10-01

    Density-corrected DFT is a method that cures several failures of self-consistent semilocal DFT calculations by using a more accurate density instead. A novel procedure employs the Hartree-Fock density to bonds that are more severely stretched than ever before. This substantially increases the range of accurate potential energy surfaces obtainable from semilocal DFT for many heteronuclear molecules. We show that this works for both neutral and charged molecules. We explain why and explore more difficult cases, for example, CH(+), where density-corrected DFT results are even better than sophisticated methods like CCSD. We give a simple criterion for when DC-DFT should be more accurate than self-consistent DFT that can be applied for most cases.

  11. Stabilized Quasi-Newton Optimization of Noisy Potential Energy Surfaces

    CERN Document Server

    Schaefer, Bastian; Roy, Shantanu; Goedecker, Stefan

    2014-01-01

    Optimizations of atomic positions belong to the most commonly performed tasks in electronic structure calculations. Many simulations like global minimum searches or characterizations of chemical reactions require performing hundreds or thousands of minimizations or saddle computations. To automatize these tasks, optimization algorithms must not only be efficient, but also very reliable. Unfortunately computational noise in forces and energies is inherent to electronic structure codes. This computational noise poses a sever problem to the stability of efficient optimization methods like the limited-memory Broyden-Fletcher-Goldfarb-Shanno algorithm. We here present a technique that allows obtaining significant curvature information of noisy potential energy surfaces. We use this technique to construct both, a stabilized quasi-Newton minimization method and a stabilized quasi-Newton saddle finding approach. We demonstrate with the help of benchmarks that both the minimizer and the saddle finding approach are sup...

  12. Multireference configuration interaction potential curve and analytical potential energy function of the ground and low-lying excited states of CdSe

    Institute of Scientific and Technical Information of China (English)

    Gao Feng; Yang Chuan-Lu; Hu Zhen-Yan; Wang Mei-Shan

    2007-01-01

    The potential energy curves (PECs) of the ground state (3Π) and three low-lying excited states (1∑, 3∑,1Π) of CdSe dimer have been studied by emploging quasirelativistic effective core potentials on the basis of the complete active space self-consistent field method followed by multireference configuration interaction calculation. The four PECs are fitted to analytical potential energy functions using the Murrel-Sorbie potential function. Based on the PECs,the vibrational levels of the four states are determined by solving the Schr(o)dinger equation of nuclear motion, and corresponding spectroscopic contants are accurately calculated. The equilibrium positions as well as the spectroscopic constants and the vibrational levels are reported. By our analysis, the 3Π state, of which the dissociation asymptote is Cd(1S) + Se(3p), is identified as a ground state of CdSe dimer, and the corresponding dissociation energy is estimated to be 0.39eV. However, the first excited state is only 1132.49cm-1 above the ground state and the 3∑ state is the highest in the four calculated states.

  13. Theoreticalstudy of the structure and analytic potential energy function for the ground state of the PO2 molecule

    Institute of Scientific and Technical Information of China (English)

    Zeng Hui; Zhao Jun

    2012-01-01

    In this paper,the energy,equilibrium geometry,and harmonic frequency of the ground electronic state of PO2 are computed using the B3LYP,B3P86,CCSD(T),and QCISD(T) methods in conjunction with the 6-311++G(3df,3pd) and cc-pVTZ basis sets.A comparison between the computational results and the experimental values indicates that the B3P86/6-311++G(3df,3pd) method can give better energy calculation results for the PO2 molecule.It is shown that the ground state of the PO2 molecule has C2v symmetry and its ground electronic state is X2A1.The equilibrium parameters of the structure are Rp-O =0.1465 nm,∠OPO =134.96°,and the dissociation energy is Ed =19.218 eV.The bent vibrational frequency v1 =386 cm-1,symmetric stretching frequency v2 =1095 cm-1,and asymmetric stretching frequency v3 =1333 cm-1 are obtained.On the basis of atomic and molecular reaction statics,a reasonable dissociation limit for the ground state of the PO2 molecule is determined.Then the analytic potential energy function of the PO2 molecule is derived using many-body expansion theory.The potential curves correctly reproduce the configurations and the dissociation energy for the PO2 molecule.

  14. Positive and ground state solutions for the critical Klein-Gordon-Maxwell system with potentials

    CERN Document Server

    Carriao, Paulo C; Miyagaki, Olimpio H

    2010-01-01

    In this paper we study a class of Klein-Gordon-Maxwell system when the nonlinearity exhibits critical growth. First we prove both existence and ground state solutions for this system with a periodic potencial V, and then we show the existence in the case that a nonperiodic potencial V is introduced.

  15. Theoretical study of potential energy surface and vibrational spectra of ArF2 system

    Institute of Scientific and Technical Information of China (English)

    杨明晖; 谢代前; 鄢国森

    2000-01-01

    An ab initio potential energy surface (PES) of ArF2 system has been obtained by using MP4 calculation with a large basis set including bond functions. There are two local minimums on the PES: one is T-shaped and the other is L-shaped. The L-shaped minimum is the global minimum with a well depth of -119.62 cm- 1 at R = 0.3883nm. The T-shaped minimum has a well depth of -85.93cm -1 at R = 0.3486 nm. A saddle point is found at R = 0.3486 and θ = 61° with the well depth of -61.53 cm-1. The vibrational energy levels have been calculated by using VSCF-CI method. The results show that this PES supports 27 vibrational bound states, and the ground states are two degenerate states assigned to the L-type vibration.

  16. Theoretical study of potential energy surface and vibrational spectra of ArF2 system

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An ab initio potential energy surface (PES) of ArF2 system has been obtained by using MP4 calculation with a large basis set including bond functions. There are two local minimums on the PES: one is T-shaped and the other is L-shaped. The L-shaped minimum is the global minimum with a well depth of -119.62 cm-1 at R = 0.3883nm. The T-shaped minimum has a well depth of -85.93cm-1 at R = 0.3486 nm. A saddle point is found at R = 0.3486 and q = 61° with the well depth of -61.53 cm-1. The vibrational energy levels have been calculated by using VSCF-CI method. The results show that this PES supports 27 vibrational bound states, and the ground states are two degenerate states assigned to the L-type vibration.

  17. Microscopically derived potential energy surfaces from mostly structural considerations

    Energy Technology Data Exchange (ETDEWEB)

    Ermamatov, M.J. [Instituto de Física, Universidade Federal Fluminense, 24210-340, Niterói, Rio de Janeiro (Brazil); Institute of Nuclear Physics, Ulughbek, Tashkent 100214 (Uzbekistan); Hess, Peter O., E-mail: hess@nucleares.unam.mx [Instituto de Ciencias Nucleares, UNAM, Circuito Exterior, C.U., A.P. 70-543, 04510, Mexico D.F. (Mexico)

    2016-08-15

    A simple procedure to estimate the quadrupole Potential-Energy-Surface (PES) is presented, using mainly structural information, namely the content of the shell model space and the Pauli exclusion principle. Further microscopic properties are implicitly contained through the use of results from the Möller and Nix tables or experimental information. A mapping to the geometric potential is performed yielding the PES. The General Collective Model is used in order to obtain an estimate on the spectrum and quadrupole transitions, adjusting only the mass parameter. First, we test the conjecture on known nuclei, deriving the PES and compare them to known data. We will see that the PES approximates very well the structure expected. Having acquired a certain confidence, we predict the PES of several chain of isotopes of heavy and super-heavy nuclei and at the end we investigate the structure of nuclei in the supposed island of stability. One of the main points to show is that simple assumptions can provide already important information on the structure of nuclei outside known regions and that spectra and electromagnetic transitions can be estimated without using involved calculations and assumptions. The procedure does not allow to calculate binding energies. The method presented can be viewed as a starting point for further improvements.

  18. Nutrients in ground water and surface water of the United States; an analysis of data through 1992

    Science.gov (United States)

    Mueller, D.K.; Hamilton, P.A.; Helsel, D.R.; Hitt, K.J.; Ruddy, B.C.

    1995-01-01

    Historical data on nutrient (nitrogen and phosphorus species) concentrations in ground-and surface-water samples were compiled from 20 study units of the National Water-Quality Assessment (NAWQA) Program and 5 supplemental study areas. The resultant national retrospective data sets contained analyses of about 12,000 Found-water and more than 22,000 surface-water samples. These data were interpreted on regional and national scales by relating the distributions of nutrient concentrations to ancillary data, such as land use, soil characteristics, and hydrogeology, provided by local study-unit personnel. The information provided in this report on environmental factors that affect nutrient concentrations in ground and surface water can be used to identify areas of the Nation where the vulnerability to nutrient contamination is greatest. Nitrate was the nutrient of greatest concern in the historical ground-water data. It is the only nutrient that is regulated by a national drinking-water standard. Nitrate concentrations were significantly different in ground water affected by various land uses. Concentrations in about 16 percent of the samples collected in agricultural areas exceeded the drinking-water standard. However, the standard was exceeded in only about 1 percent of samples collected from public-supply wells. A variety of ancillary factors had significant relations to nitrate concentrations in ground water beneath agricultural areas. Concentrations generally were highest within 100 feet of the land surface. They were also higher in areas where soil and geologic characteristics promoted rapid movement of water to the aquifer. Elevated concentrations commonly occurred in areas underlain by permeable materials, such as carbonate bedrock or unconsolidated sand and gravel, and where soils are generally well drained. In areas where water movement is impeded, denitrification might lead to low concentrations of nitrate in the ground water. Low concentrations were also

  19. Methods for characterizing fine particulate matter using ground observations and remotely sensed data: potential use for environmental public health surveillance.

    Science.gov (United States)

    Al-Hamdan, Mohammad Z; Crosson, William L; Limaye, Ashutosh S; Rickman, Douglas L; Quattrochi, Dale A; Estes, Maurice G; Qualters, Judith R; Sinclair, Amber H; Tolsma, Dennis D; Adeniyi, Kafayat A; Niskar, Amanda Sue

    2009-07-01

    This study describes and demonstrates different techniques for surface fitting daily environmental hazards data of particulate matter with aerodynamic diameter less than or equal to 2.5 microm (PM2.5) for the purpose of integrating respiratory health and environmental data for the Centers for Disease Control and Prevention (CDC) pilot study of Health and Environment Linked for Information Exchange (HELIX)-Atlanta. It presents a methodology for estimating daily spatial surfaces of ground-level PM2.5 concentrations using the B-Spline and inverse distance weighting (IDW) surface-fitting techniques, leveraging National Aeronautics and Space Administration (NASA) Moderate Resolution Imaging Spectrometer (MODIS) data to complement U.S. Environmental Protection Agency (EPA) ground observation data. The study used measurements of ambient PM2.5 from the EPA database for the year 2003 as well as PM2.5 estimates derived from NASA's satellite data. Hazard data have been processed to derive the surrogate PM2.5 exposure estimates. This paper shows that merging MODIS remote sensing data with surface observations of PM,2. not only provides a more complete daily representation of PM,2. than either dataset alone would allow, but it also reduces the errors in the PM2.5-estimated surfaces. The results of this study also show that although the IDW technique can introduce some numerical artifacts that could be due to its interpolating nature, which assumes that the maxima and minima can occur only at the observation points, the daily IDW PM2.5 surfaces had smaller errors in general, with respect to observations, than those of the B-Spline surfaces. Finally, the methods discussed in this paper establish a foundation for environmental public health linkage and association studies for which determining the concentrations of an environmental hazard such as PM2.5 with high accuracy is critical.

  20. Colored grounds of gilt stucco surfaces as analyzed by a combined microscopic, spectroscopic and elemental analytical approach.

    Science.gov (United States)

    Sansonetti, A; Striova, J; Biondelli, D; Castellucci, E M

    2010-08-01

    A survey of gilts applied to stucco surfaces that specifically focuses on the compositions of their colored grounds is reported. Gilt samples of a common geographical (Lombardy in Italy) and temporal provenance (17th-18th century) were studied in the form of polished cross-sections by optical and electron microscopy (SEM-EDS), micro-Raman (microRaman) spectroscopy and Fourier-transform infrared microspectroscopy (microFTIR). Comparing samples with superimposed grounds and gilts enabled light to be shed on the choice of specific materials, their stratigraphic functions, decorative effects, and technological performances. Iron oxide pigments were found in the older grounds, sometimes in the presence of lead white (2PbCO(3).Pb(OH)(2)) or minium (Pb(3)O(4)). In more recent grounds, chrome yellow (PbCrO(4)), chrome orange (PbCrO(4).PbO), cinnabar (alpha-HgS) and barium white (BaSO(4)), invariably mixed with lead white, were encountered. Evidence for the use of organic mordants (colophony and wax, or siccative oil) was obtained by microFTIR. This combined microFTIR and microRaman spectroscopic and elemental (SEM-EDS) analytical approach enhances knowledge of the composition of gold grounds, their variability and their chronological evolution.

  1. Informing hydrological models with ground-based time-lapse relative gravimetry: potential and limitations

    DEFF Research Database (Denmark)

    Bauer-Gottwein, Peter; Christiansen, Lars; Rosbjerg, Dan

    2011-01-01

    parameter uncertainty decreased significantly when TLRG data was included in the inversion. The forced infiltration experiment caused changes in unsaturated zone storage, which were monitored using TLRG and ground-penetrating radar. A numerical unsaturated zone model was subsequently conditioned on both...... in gravity due to unmonitored non-hydrological effects, and the requirement of a gravitationally stable reference station. Application of TLRG in hydrology should be combined with other geophysical and/or traditional monitoring methods....

  2. The study of single station inverting the sea surface current by HF ground wave radar based on adjoint assimilation technology

    Science.gov (United States)

    Han, Shuzong; Yang, Hua; Xue, Wenhu; Wang, Xingchi

    2017-06-01

    This paper introduces the assimilation technology in an ocean dynamics model and discusses the feasibility of inverting the sea surface current in the detection zone by assimilating the sea current radial velocity detected by single station HF ground wave radar in ocean dynamics model. Based on the adjoint assimilation and POM model, the paper successfully inverts the sea surface current through single station HF ground wave radar in the Zhoushan sea area. The single station HF radar inversion results are also compared with the bistatic HF radar composite results and the fixed point measured results by Annderaa current meter. The error analysis shows that acquisition of flow velocity and flow direction data from the single station HF radar based on adjoint assimilation and POM model is viable and the data obtained have a high correlation and consistency with the flow field observed by HF radar.

  3. Surface electrochemical properties of red mud (bauxite residue): zeta potential and surface charge density.

    Science.gov (United States)

    Liu, Yanju; Naidu, Ravendra; Ming, Hui

    2013-03-15

    The surface electrochemical properties of red mud (bauxite residue) from different alumina refineries in Australia and China were studied by electrophoresis and measuring surface charge density obtained from acid/base potentiometric titrations. The electrophoretic properties were measured from zeta potentials obtained in the presence of 0.01 and 0.001 M KNO(3) over a wide pH range (3.5-10) by titration. The isoelectric point (IEP) values were found to vary from 6.35 to 8.70 for the red mud samples. Further investigation into the surface charge density of one sample (RRM) by acid/base potentiometric titration showed similar results for pH(PZC) with pH(IEP) obtained from electrokinetic measurements. The pH(IEP) determined from zeta potential measurements can be used as a characteristic property of red mud. The minerals contained in red mud contributed to the different values of pH(IEP) of samples obtained from different refineries. Different relationships of pH(IEP) with Al/Fe and Al/Si ratios (molar basis) were also found for different red mud samples.

  4. SURFACE WATER AND GROUND WATER QUALITY MONITORING FOR RESTORATION OF URBAN LAKES IN GREATER HYDERABAD, INDIA

    Science.gov (United States)

    Mohanty, A. K.

    2009-12-01

    SURFACE WATER AND GROUND WATER QUALITY MONITORING FOR RESTORATION OF URBAN LAKES IN GREATER HYDERABAD, INDIA A.K. Mohanty, K. Mahesh Kumar, B. A. Prakash and V.V.S. Gurunadha Rao Ecology and Environment Group National Geophysical Research Institute, (CSIR) Hyderabad - 500 606, India E-mail:atulyakumarmohanty@yahoo.com Abstract: Hyderabad Metropolitan Development Authority has taken up restoration of urban lakes around Hyderabad city under Green Hyderabad Environment Program. Restoration of Mir Alam Tank, Durgamcheruvu, Patel cheruvu, Pedda Cheruvu and Nallacheruvu lakes have been taken up under the second phase. There are of six lakes viz., RKPuramcheruvu, Nadimicheruvu (Safilguda), Bandacheruvu Patelcheruvu, Peddacheruvu, Nallacheruvu, in North East Musi Basin covering 38 sq km. Bimonthly monitoring of lake water quality for BOD, COD, Total Nitrogen, Total phosphorous has been carried out for two hydrological cycles during October 2002- October 2004 in all the five lakes at inlet channels and outlets. The sediments in the lake have been also assessed for nutrient status. The nutrient parameters have been used to assess eutrophic condition through computation of Trophic Status Index, which has indicated that all the above lakes under study are under hyper-eutrophic condition. The hydrogeological, geophysical, water quality and groundwater data base collected in two watersheds covering 4 lakes has been used to construct groundwater flow and mass transport models. The interaction of lake-water with groundwater has been computed for assessing the lake water budget combining with inflow and outflow measurements on streams entering and leaving the lakes. Individual lake water budget has been used for design of appropriate capacity of Sewage Treatment Plants (STPs) on the inlet channels of the lakes for maintaining Full Tank Level (FTL) in each lake. STPs are designed for tertiary treatment i.e. removal of nutrient load viz., Phosphates and Nitrates. Phosphates are

  5. Methane dissociation on Ni(111): A fifteen-dimensional potential energy surface using neural network method

    Science.gov (United States)

    Shen, Xiangjian; Chen, Jun; Zhang, Zhaojun; Shao, Kejie; Zhang, Dong H.

    2015-10-01

    In the present work, we develop a highly accurate, fifteen-dimensional potential energy surface (PES) of CH4 interacting on a rigid flat Ni(111) surface with the methodology of neural network (NN) fit to a database consisted of about 194 208 ab initio density functional theory (DFT) energy points. Some careful tests of the accuracy of the fitting PES are given through the descriptions of the fitting quality, vibrational spectrum of CH4 in vacuum, transition state (TS) geometries as well as the activation barriers. Using a 25-60-60-1 NN structure, we obtain one of the best PESs with the least root mean square errors: 10.11 meV for the entrance region and 17.00 meV for the interaction and product regions. Our PES can reproduce the DFT results very well in particular for the important TS structures. Furthermore, we present the sticking probability S0 of ground state CH4 at the experimental surface temperature using some sudden approximations by Jackson's group. An in-depth explanation is given for the underestimated sticking probability.

  6. Efficient simulation of wave-packet dynamics on multiple coupled potential surfaces with split potential propagation

    CERN Document Server

    Aharonovich, Igal

    2016-01-01

    We present a simple method to expedite simulation of quantum wave-packet dynamics by more than a factor of $2$ with the Strang split-operator propagation. Dynamics of quantum wave-packets are often evaluated using the the \\emph{Strang} split-step propagation, where the kinetic part of the Hamiltonian $\\hat{T}$ and the potential part $\\hat{V}$ are piecewise integrated according to $e^{- i \\hat{H} \\delta t} \\approx e^{- i \\hat{V} \\delta t/2} e^{- i \\hat{T}\\delta t} e^{- i \\hat{V} \\delta t/2}$, which is accurate to second order in the propagation time $\\delta t$. In molecular quantum dynamics, the potential propagation occurs over multiple coupled potential surfaces and requires matrix exponentiation for each position in space and time which is computationally demanding. Our method employs further splitting of the potential matrix $\\hat{V}$ into a diagonal space dependent part $\\hat{V}_{D}(R)$ and an off-diagonal time-dependent coupling-field $\\hat{V}_{OD}(t)$, which then requires only a single matrix exponentia...

  7. Simulated potentiometric surface contours at end of simulation (1998) in model layer 1 of the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These contours represent the simulated potentiometric surface at the end of simulation (1998) in model layer 1 of the Death Valley regional ground-water flow system...

  8. Simulated potentiometric surface contours of prepumping conditions in layer 1 of the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These simulated potentiometric surface contours represent prepumping (or steady-state) conditions for model layer 1 of the Death Valley regional ground-water flow...

  9. Simulated potentiometric surface contours of prepumping conditions in layer 16 of the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These simulated potentiometric surface contours represent prepumping (or steady-state) conditions for model layer 16 of the Death Valley regional ground-water flow...

  10. Simulated potentiometric surface contours at end of simulation (1998) in model layer 16 of the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These contours represent the simulated potentiometric surface at the end of simulation (1998) in model layer 16 of the Death Valley regional ground-water flow system...

  11. Simulated potentiometric surface contours at end of simulation (1998) in model layer 1 of the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These contours represent the simulated potentiometric surface at the end of simulation (1998) in model layer 1 of the Death Valley regional ground-water flow system...

  12. Simulated potentiometric surface contours at end of simulation (1998) in model layer 16 of the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These contours represent the simulated potentiometric surface at the end of simulation (1998) in model layer 16 of the Death Valley regional ground-water flow...

  13. Development of a Remotely Operated, Field-Deployable Tritium Analysis System for Surface and Ground Water Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Hofstetter, K.J. [Westinghouse Savannah River Company, AIKEN, SC (United States); Cable, P.R.; Noakes, J.E. [University of Georgia, , GA (United States); Spaulding, J.D. [University of Georgia, , GA (United States); Neary, M. P. [University of Georgia, , GA (United States); Wasyl, M.S. [Packard Instrument Company, , ()

    1996-06-20

    The environmental contamination resulting from decades of testing and manufacturing of nuclear materials for a national defense purposes is a problem now being faced by the United States. The Center for Applied Isotope Studies at the University of Georgia, in cooperation with the Westinghouse Savannah River Company and Packard Instrument Company, have developed a prototype unit for remote, near real time, in situ analysis of tritium in surface and ground water samples.

  14. Interpolation of multi-sheeted multi-dimensional potential-energy surfaces via a linear optimization procedure.

    Science.gov (United States)

    Opalka, Daniel; Domcke, Wolfgang

    2013-06-14

    Significant progress has been achieved in recent years with the development of high-dimensional permutationally invariant analytic Born-Oppenheimer potential-energy surfaces, making use of polynomial invariant theory. In this work, we have developed a generalization of this approach which is suitable for the construction of multi-sheeted multi-dimensional potential-energy surfaces exhibiting seams of conical intersections. The method avoids the nonlinear optimization problem which is encountered in the construction of multi-sheeted diabatic potential-energy surfaces from ab initio electronic-structure data. The key of the method is the expansion of the coefficients of the characteristic polynomial in polynomials which are invariant with respect to the point group of the molecule or the permutation group of like atoms. The multi-sheeted adiabatic potential-energy surface is obtained from the Frobenius companion matrix which contains the fitted coefficients. A three-sheeted nine-dimensional adiabatic potential-energy surface of the (2)T2 electronic ground state of the methane cation has been constructed as an example of the application of this method.

  15. Constrained Broyden Dimer Method with Bias Potential for Exploring Potential Energy Surface of Multistep Reaction Process.

    Science.gov (United States)

    Shang, Cheng; Liu, Zhi-Pan

    2012-07-10

    To predict the chemical activity of new matter is an ultimate goal in chemistry. The identification of reaction pathways using modern quantum mechanics calculations, however, often requires a high demand in computational power and good chemical intuition on the reaction. Here, a new reaction path searching method is developed by combining our recently developed transition state (TS) location method, namely, the constrained Broyden dimer method, with a basin-filling method via bias potentials, which allows the system to walk out from the energy traps at a given reaction direction. In the new method, the reaction path searching starts from an initial state without the need for preguessing the TS-like or final state structure and can proceed iteratively to the final state by locating all related TSs and intermediates. In each elementary reaction step, a reaction direction, such as a bond breaking, needs to be specified, the information of which is refined and preserved as a normal mode through biased dimer rotation. The method is tested successfully on the Baker reaction system (50 elementary reactions) with good efficiency and stability and is also applied to the potential energy surface exploration of multistep reaction processes in the gas phase and on the surface. The new method can be applied for the computational screening of new catalytic materials with a minimum requirement of chemical intuition.

  16. Lithium content in potable water, surface water, ground water, and mineral water on the territory of Republic of Macedonia

    Directory of Open Access Journals (Sweden)

    Vesna Kostik

    2014-07-01

    Full Text Available The aim of this study was to determine lithium concentration in potable water, surface water, ground, and mineral water on the territory of the Republic of Macedonia. Water samples were collected from water bodies such as multiple public water supply systems located in 13 cities, wells boreholes located in 12 areas, lakes and rivers located in three different areas. Determination of lithium concentration in potable water, surface water was performed by the technique of inductively coupled plasma-mass spectrometry, while in ground water samples from wells boreholes and mineral waters with the technique of ion chromatography. The research shows that lithium concentration in potable water ranging from 0.1 to 5.2 μg/L; in surface water from 0.5 to 15.0 μg/L; ground water from wells boreholes from 16.0 to 49.1 μg/L and mineral water from 125.2 to 484.9 μg/L. Obtained values are in accordance with the relevant international values for the lithium content in water.

  17. From Ground Truth to Space: Surface, Subsurface and Remote Observations Associated with Nuclear Test Detection

    Science.gov (United States)

    Sussman, A. J.; Anderson, D.; Burt, C.; Craven, J.; Kimblin, C.; McKenna, I.; Schultz-Fellenz, E. S.; Miller, E.; Yocky, D. A.; Haas, D.

    2016-12-01

    Underground nuclear explosions (UNEs) result in numerous signatures that manifest on a wide range of temporal and spatial scales. Currently, prompt signals, such as the detection of seismic waves provide only generalized locations and the timing and amplitude of non-prompt signals are difficult to predict. As such, research into improving the detection, location, and identification of suspect events has been conducted, resulting in advancement of nuclear test detection science. In this presentation, we demonstrate the scalar variably of surface and subsurface observables, briefly discuss current capabilities to locate, detect and characterize potential nuclear explosion locations, and explain how emergent technologies and amalgamation of disparate data sets will facilitate improved monitoring and verification. At the smaller scales, material and fracture characterization efforts on rock collected from legacy UNE sites and from underground experiments using chemical explosions can be incorporated into predictive modeling efforts. Spatial analyses of digital elevation models and orthoimagery of both modern conventional and legacy nuclear sites show subtle surface topographic changes and damage at nearby outcrops. Additionally, at sites where such technology cannot penetrate vegetative cover, it is possible to use the vegetation itself as both a companion signature reflecting geologic conditions and showing subsurface impacts to water, nutrients, and chemicals. Aerial systems based on RGB imagery, light detection and ranging, and hyperspectral imaging can allow for combined remote sensing modalities to perform pattern recognition and classification tasks. Finally, more remote systems such as satellite based synthetic aperture radar and satellite imagery are other techniques in development for UNE site detection, location and characterization.

  18. Surface potential determination in metal-oxide-semiconductor capacitors

    Science.gov (United States)

    Moragues, J. M.; Ciantar, E.; Jerisian, R.; Sagnes, B.; Oualid, J.

    1994-11-01

    Different methods using the relationship between surface potential Psi(sub S) and gate bias V(sub G) in metal-oxide-semiconductor (MOS) capacitors have been compared. These methods can be applied even if the doping profile is very abrupt and the interface state density very high. The shifts of midgap, flatband, and threshold voltages, observed after Fowler-Nordheim electron injection, and deduced from the various Psi(sub S(V (sub G)) relationships obtained by these different methods, are in good agreement. These shifts give the number of effective oxide trapped charges (N(sub ox)) per unit area and acceptor-like and donor-like interface states (N(sub SS)A and N(sub SS)D) which are created during the electron injection. We reveal that the number of positive charges created in the gate oxide, unlike the number of generated interface states, strongly depends on the position of the post-metallization annealing step in the process. After relaxation of the stressed MOS capacitors, most of the generated positive charges can be attributed, in the MOS capacitors studied, to hydrogen-related species. It seems that the interface states are essentially created by the recombination of holes generated by electron impact.

  19. Potential therapeutic applications of microbial surface-active compounds

    Directory of Open Access Journals (Sweden)

    Letizia Fracchia

    2015-08-01

    Full Text Available Numerous investigations of microbial surface-active compounds or biosurfactants over the past two decades have led to the discovery of many interesting physicochemical and biological properties including antimicrobial, anti-biofilm and therapeutic among many other pharmaceutical and medical applications. Microbial control and inhibition strategies involving the use of antibiotics are becoming continually challenged due to the emergence of resistant strains mostly embedded within biofilm formations that are difficult to eradicate. Different aspects of antimicrobial and anti-biofilm control are becoming issues of increasing importance in clinical, hygiene, therapeutic and other applications. Biosurfactants research has resulted in increasing interest into their ability to inhibit microbial activity and disperse microbial biofilms in addition to being mostly nontoxic and stable at extremes conditions. Some biosurfactants are now in use in clinical, food and environmental fields, whilst others remain under investigation and development. The dispersal properties of biosurfactants have been shown to rival that of conventional inhibitory agents against bacterial, fungal and yeast biofilms as well as viral membrane structures. This presents them as potential candidates for future uses in new generations of antimicrobial agents or as adjuvants to other antibiotics and use as preservatives for microbial suppression and eradication strategies.

  20. Effects of exchange-correlation potentials in density functional descriptions of ground-state and photoionization of fullerenes

    Science.gov (United States)

    Choi, Jinwoo; Chang, Eonho; Anstine, Dylan M.; Chakraborty, Himadri

    2016-05-01

    We study the ground state properties of C60 and C240 molecules in a spherical frame of local density approximation (LDA). Within this mean-field theory, two different approximations to the exchange-correlation (xc) functional are used: (i) The Gunnerson-Lundqvist parametrization augmented by a treatment to correct for the electron self-interaction and (ii) the van Leeuwen and Baerends (LB94) model potential that inclusively restores electron's asymptotic properties. Results show differences in the ground-state potential, level energies and electron densities between the two xc choices. We then use the ground structure to find the excited and ionized states of the systems and calculate dipole single-photoionization cross sections in a time-dependent LDA method that incorporates linear-response dynamical correlations. Comparative effects of the choices of xc on collective plasmon and single-excitation Auger resonances as well as on geometry driven cavity oscillations are found significant. The work is supported by the NSF, USA.

  1. Potential crop evapotranspiration and surface evaporation estimates via a gridded weather forcing dataset

    Science.gov (United States)

    Lewis, Clayton S.; Allen, L. Niel

    2017-03-01

    Absent local weather stations, a gridded weather dataset can provide information useful for water management in irrigated areas including potential crop evapotranspiration calculations. In estimating crop irrigation requirements and surface evaporation in Utah, United States of America, methodology and software were developed using the ASCE Standardized Penman-Monteith Reference Evapotranspiration equation with input climate drivers from the North American Land Data Assimilation System (NLDAS) gridded weather forcing dataset and a digital elevation model. A simple procedure was devised to correct bias in NLDAS relative humidity and air temperature data based on comparison to weather data from ground stations. Potential evapotranspiration was calculated for 18 crops (including turfgrass), wetlands (large and narrow), and open water evaporation (deep and shallow) by multiplying crop coefficient curves to reference evapotranspiration with annual curve dates set by summation of Hargreaves evapotranspiration, cumulative growing degree days, or number of days. Net potential evapotranspiration was calculated by subtracting effective precipitation estimates from the Daymet gridded precipitation dataset. Analysis of the results showed that daily estimated potential crop evapotranspiration from the model compared well with estimates from electronic weather stations (1980-2014) and with independently calculated potential crop evapotranspiration in adjacent states. Designed for this study but open sourced for other applications, software entitled GridET encapsulated the GIS-based model that provided data download and management, calculation of reference and potential crop evapotranspiration, and viewing and analysis tools. Flexible features in GridET allows a user to specify grid resolution, evapotranspiration equations, cropping information, and additional datasets with the output being transferable to other GIS software.

  2. Potential of Multitemporal Tandem-X Derived Crop Surface Models for Maize Growth Monitoring

    Science.gov (United States)

    Hütt, C.; Tilly, N.; Schiedung, H.; Bareth, G.

    2016-06-01

    In this study, first results of retrieving plant heights of maize fields from multitemporal TanDEM-X images are shown. Three TanDEM-X dual polarization spotlight acquisitions were taken over a rural area in Germany in the growing season 2014. By interferometric processing, digital terrain models (DTM) were derived for each date with 5m resolution. From the data of the first acquisition (June 1st) taken before planting, a DTM of the bare ground is generated. The data of the following acquisition dates (July 15th, July 26th) are used to establish crop surface models (CSM). A CSM represents the crop surface of a whole field in a high resolution. By subtracting the DTM of the ground from each CSM, the actual plant height is calculated. Within these data sets 30 maize fields in the area of interest could be detected and verified by external land use data. Besides the spaceborne measurements, one of the maize fields was intensively investigated using terrestrial laser scanning (TLS), which was carried out at the same dates as the predicted TanDEM-X acquisitions. Visual inspection of the derived plant heights, and accordance of the individually processed polarisations over the maize fields, demonstrate the feasibility of the proposed method. Unfortunately, the infield variability of the intensively monitored field could not be successfully captured in the TanDEM-X derived plant heights and merely the general trend is visible. Nevertheless, the study shows the potential of the TanDEM-X constellation for maize height monitoring on field level.

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

    Science.gov (United States)

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

  4. Areal-Averaged Spectral Surface Albedo in an Atlantic Coastal Area: Estimation from Ground-Based Transmission

    Directory of Open Access Journals (Sweden)

    Evgueni Kassianov

    2017-07-01

    Full Text Available Tower-based data combined with high-resolution satellite products have been used to produce surface albedo at various spatial scales over land. Because tower-based albedo data are available at only a few sites, surface albedos using these combined data are spatially limited. Moreover, tower-based albedo data are not representative of highly heterogeneous regions. To produce areal-averaged and spectrally-resolved surface albedo for regions with various degrees of surface heterogeneity, we have developed a transmission-based retrieval and demonstrated its feasibility for relatively homogeneous land surfaces. Here, we demonstrate its feasibility for a highly heterogeneous coastal region. We use the atmospheric transmission measured during a 19-month period (June 2009–December 2010 by a ground-based Multi-Filter Rotating Shadowband Radiometer (MFRSR at five wavelengths (0.415, 0.5, 0.615, 0.673 and 0.87 µm at the Department of Energy’s Atmospheric Radiation Measurement (ARM Mobile Facility (AMF site located on Graciosa Island. We compare the MFRSR-retrieved areal-averaged surface albedo with albedo derived from Moderate Resolution Imaging Spectroradiometer (MODIS observations, and also a composite-based albedo. We demonstrate that these three methods produce similar spectral signatures of surface albedo; however, the MFRSR-retrieved albedo, is higher on average (≤0.04 than the MODIS-based areal-averaged surface albedo and the largest difference occurs in winter.

  5. Effect of the surface geology on strong ground motions due to the 2016 Central Tottori Earthquake, Japan

    Science.gov (United States)

    Kagawa, Takao; Noguchi, Tatsuya; Yoshida, Shohei; Yamamoto, Shinji

    2017-08-01

    On October 21, 2016, an earthquake with Japan Meteorological Agency (JMA) magnitude 6.6 hit the central part of Tottori Prefecture, Japan. This paper demonstrates two notable effects of the surface geology on strong ground motions due to the earthquake. One is a predominant period issue observed over a large area. A seismic intensity of 6 lower on the JMA scale was registered at three sites in the disaster area. However, the peak ground acceleration ranged from 0.3 to 1.4 G at the three sites because of the varying peak periods of observed strong ground motions. The spectral properties of the observations also reflect the damage around the sites. Three-component microtremors were observed in the area; the predominant ground period distributions based on horizontal to vertical spectral ratios were provided by the authors. The peak periods of the strong motion records agree well with predominant periods estimated from microtremor observations at a rather hard site; however, the predominant periods of the microtremors are slightly shorter than those of the main shock at the other two soft sites. We checked the nonlinear effect at the sites by comparing the site responses to small events and the main shock. The peak periods of the main shock were longer than those of the weak motions at the sites. This phenomenon indicates a nonlinear site effect due to large ground motions caused by the main shock. A horizontal component of the accelerogram showed rather pulsating swings that indicate cyclic mobility behavior, especially at a site close to a pond shore; ground subsidence of 20 cm was observed around the site. The peak periods of weak motions agree well with those of the microtremor observations. This implies an important issue that the predominant periods estimated by microtremors are not sufficient to estimate the effect of surface geology for disaster mitigation. We have to estimate the predominant periods under large ground motions considering the nonlinear site

  6. Comparison of MTI and Ground Truth Sea Surface Temperatures at Nauru

    Energy Technology Data Exchange (ETDEWEB)

    Kurzeja, R.

    2002-09-05

    This report evaluates MTI-derived surface water temperature near the tropical Pacific island of Nauru. The MTI sea-surface temperatures were determined by the Los Alamos National Laboratory based on the robust retrieval.

  7. Force Restore Technique for Ground Surface Temperature and Moisture Content in a Dry Desert System

    NARCIS (Netherlands)

    Jacobs, A.F.G.; Heusinkveld, B.G.; Berkowicz, S.

    2000-01-01

    The level of the surface temperature as well as surface moisture content is important for the turbulent transports of sensible and latent heat, respectively, but this level is also crucial for the survival of shrubs, plants, insects, and small animals in a desert environment. To estimate the surface

  8. Questa baseline and pre-mining ground-water quality investigation. 5. Well installation, water-level data, and surface- and ground-water geochemistry in the Straight Creek drainage basin, Red River Valley, New Mexico, 2001-03

    Science.gov (United States)

    Naus, Cheryl A.; McCleskey, R. Blaine; Nordstrom, D. Kirk; Donohoe, Lisa C.; Hunt, Andrew G.; Paillet, Frederick L.; Morin, Roger H.; Verplanck, Philip L.

    2005-01-01

    The U.S. Geological Survey, in cooperation with the New Mexico Environment Department, is investigating the pre-mining ground-water chemistry at the Molycorp molybdenum mine in the Red River Valley, northern New Mexico. The primary approach is to determine the processes controlling ground-water chemistry at an unmined, off-site, proximal analog. The Straight Creek drainage basin, chosen for this purpose, consists of the same quartz-sericite-pyrite altered andesitic and rhyolitic volcanic rock of Tertiary age as the mine site. The weathered and rugged volcanic bedrock surface is overlain by heterogeneous debris-flow deposits that interfinger with alluvial deposits near the confluence of Straight Creek and the Red River. Pyritized rock in the upper part of the drainage basin is the source of acid rock drainage (pH 2.8-3.3) that infiltrates debris-flow deposits containing acidic ground water (pH 3.0-4.0) and bedrock containing water of circumneutral pH values (5.6-7.7). Eleven observation wells were installed in the Straight Creek drainage basin. The wells were completed in debris-flow deposits, bedrock, and interfingering debris-flow and Red River alluvial deposits. Chemical analyses of ground water from these wells, combined with chemical analyses of surface water, water-level data, and lithologic and geophysical logs, provided information used to develop an understanding of the processes contributing to the chemistry of ground water in the Straight Creek drainage basin. Surface- and ground-water samples were routinely collected for determination of total major cations and selected trace metals; dissolved major cations, selected trace metals, and rare-earth elements; anions and alkalinity; and dissolved-iron species. Rare-earth elements were determined on selected samples only. Samples were collected for determination of dissolved organic carbon, mercury, sulfur isotopic composition (34S and 18O of sulfate), and water isotopic composition (2H and 18O) during

  9. Zoning of the territory of Russia by the effectiveness of low-potential heat of the ground and atmospheric air for heating buildings

    Science.gov (United States)

    Vasilyev, G. P.; Kolesova, M. V.; Gornov, V. F.; Yurchenko, I. A.

    2016-06-01

    The article represents the results of researches to zone the territory of Russia and Europe division into districts of by efficiency of using for the heat supply of buildings of low-potential thermal energy of ground and free air and their combination. While modeling the heat regime of geothermal HPS in climatic conditions of different regions of the territory of Russia, the influence of the long-term extraction of geothermal heat energy on the ground heat regime has been taken into account as well as the influence of phase transitions of pore moisture in ground on the efficiency of operation of geothermal heat-pump heat-supply systems. Also considered were the sinking of temperatures of ground massif by long-term extraction of the heat energy from the ground as calculation parameters of the heat energy from the ground, and as calculation parameters of ground massif temperatures.

  10. Exploration of a Polarized Surface Bidirectional Reflectance Model Using the Ground-Based Multiangle SpectroPolarimetric Imager

    Directory of Open Access Journals (Sweden)

    David J. Diner

    2012-12-01

    Full Text Available Accurate characterization of surface reflection is essential for retrieval of aerosols using downward-looking remote sensors. In this paper, observations from the Ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI are used to evaluate a surface polarized bidirectional reflectance distribution function (PBRDF model. GroundMSPI is an eight-band spectropolarimetric camera mounted on a rotating gimbal to acquire pushbroom imagery of outdoor landscapes. The camera uses a very accurate photoelastic-modulator-based polarimetric imaging technique to acquire Stokes vector measurements in three of the instrument’s bands (470, 660, and 865 nm. A description of the instrument is presented, and observations of selected targets within a scene acquired on 6 January 2010 are analyzed. Data collected during the course of the day as the Sun moved across the sky provided a range of illumination geometries that facilitated evaluation of the surface model, which is comprised of a volumetric reflection term represented by the modified Rahman-Pinty-Verstraete function plus a specular reflection term generated by a randomly oriented array of Fresnel-reflecting microfacets. While the model is fairly successful in predicting the polarized reflection from two grass targets in the scene, it does a poorer job for two manmade targets (a parking lot and a truck roof, possibly due to their greater degree of geometric organization. Several empirical adjustments to the model are explored and lead to improved fits to the data. For all targets, the data support the notion of spectral invariance in the angular shape of the unpolarized and polarized surface reflection. As noted by others, this behavior provides valuable constraints on the aerosol retrieval problem, and highlights the importance of multiangle observations.

  11. Surface-water, water-quality, and ground-water assessment of the Municipio of Comerio, Puerto Rico, 1997-99

    Science.gov (United States)

    Rodríguez-Martínez, Jesús; Gómez-Gómez, Fernando; Santiago-Rivera, Luis; Oliveras-Feliciano, M. L.

    2001-01-01

    sewer ejectors, clogged and leaking sewage pipes, septic tank leakage, unfenced livestock, runoff from livestock pens, and seepage from pits containing animal wastes. Long-term fecal coliform data at two sampling stations on the Rio de la Plata indicate that since 1984, the geometric mean of five consecutive samples commonly has been at or below 2,000 colonies per 100 milliliters (established as the sanitary quality goal in Puerto Rico for Class SD type waters). At the sampling station upstream of Comerio, the geometric mean concentration has been near 500 colonies per 100 milliliters; downstream of the town of Comerio, the geometric mean concentration has been near 2,000 colonies per 100 milliliters concentration. The data at these stations also indicate that fecal coliform concentrations increase commonly above 2,000 colonies per 100 milliliters during storm-runoff events, ranging from 1,000 to 100,000 colonies per 100 milliliters at both stations. Geologic, topographic, soil, hydrogeologic, and streamflow data were used to divide the municipio of Comerio into five hydrogeologic terranes. The integrated database was then used to evaluate the ground-water development potential of each hydrogeologic terrane. Analysis suggests that areas with slopes greater than 15 degrees have relatively low ground-water development potential. Fractures may be important locally in enhancing the water-bearing properties in the hydrogeologic terranes containing igneous rocks. The integrated hydrogeologic approach used in this study can serve as an important tool for regulatory agencies of Puerto Rico and the municipio of Comerio to evaluate the ground-water resource development potential, examine ground- and surface-water interaction, and determine the effect of land-use practices on ground-water quantity and quality. Stream low-flow statistics document the general hydrology under current land and water uses. Low-flow characteristics may substantially change as a re

  12. Potential feedbacks between snow cover, soil moisture and surface energy fluxes in Southern Norway

    Science.gov (United States)

    Brox Nilsen, Irene; Tallaksen, Lena M.; Stordal, Frode

    2017-04-01

    At high latitudes, the snow season has become shorter during the past decades because snowmelt is highly sensitive to a warmer climate. Snowmelt influences the energy balance by changing the albedo and the partitioning between latent and sensible heat fluxes. It further influences the water balance by changing the runoff and soil moisture. In a previous study, we identified southern Norway as a region where significant temperature changes in summer could potentially be explained by land-atmosphere interactions. In this study we hypothesise that changes in snow cover would influence the summer surface fluxes in the succeeding weeks or months. The exceptionally warm summer of 2014 was chosen as a test bed. In Norway, evapotranspiration is not soil moisture limited, but energy limited, under normal conditions. During warm summers, however, such as in 2014, evapotranspiration can be restricted by the available soil moisture. Using the Weather Research and Forecasting (WRF) model we replace the initial ground conditions for 2014 with conditions representative of a snow-poor spring and a snow-rich spring. WRF was coupled to Noah-MP at 3 km horizontal resolution in the inner domain, and the simulations covered mid-May through September 2014. Boundary conditions used to force WRF were taken from the Era-Interim reanalysis. Snow, runoff, soil moisture and soil temperature observational data were provided by the Norwegian Water Resources and Energy Directorate for validation. The validation shows generally good agreement with observations. Preliminary results show that the reduced snowpack, hereafter "sim1" increased the air temperature by up to 5 K and the surface temperature by up to 10 K in areas affected by snow changes. The increased snowpack, hereafter "sim2", decreased the air and surface temperature by the same amount. These are weekly mean values for the first eight simulation weeks from mid May. Because of the higher net energy available ( 100 Wm-2) in sim 1, both

  13. Scientific Ground of a New Optical Device for Contactless Measurement of the Small Spatial Displacements of Control Object Surfaces

    Science.gov (United States)

    Miroshnichenko, I. P.; Parinov, I. A.

    2017-06-01

    It is proposed the computational-experimental ground of newly developed optical device for contactless measurement of small spatial displacements of control object surfaces based on the use of new methods of laser interferometry. The proposed device allows one to register linear and angular components of the small displacements of control object surfaces during the diagnosis of the condition of structural materials for forced elements of goods under exploring by using acoustic non-destructive testing methods. The described results are the most suitable for application in the process of high-precision measurements of small linear and angular displacements of control object surfaces during experimental research, the evaluation and diagnosis of the state of construction materials for forced elements of goods, the study of fast wave propagation in layered constructions of complex shape, manufactured of anisotropic composite materials, the study of damage processes in modern construction materials in mechanical engineering, shipbuilding, aviation, instrumentation, power engineering, etc.

  14. Hydrophilic anthropogenic markers for quantification of wastewater contamination in ground- and surface waters.

    Science.gov (United States)

    Kahle, Maren; Buerge, Ignaz J; Müller, Markus D; Poiger, Thomas

    2009-12-01

    Hydrophilic, persistent markers are useful to detect, locate, and quantify contamination of natural waters with domestic wastewater. The present study focused on occurrence and fate of seven marker candidates including carbamazepine (CBZ), 10,11-dihydro-10,11-dihydroxycarbamazepine (DiOH-CBZ), primidone (PMD), crotamiton (CTMT), N-acetyl-4-aminoantipyrine (AAA), N-formyl-4-aminoantipyrine (FAA), and benzotriazole (BTri) in wastewater treatment plants (WWTPs), lakes, and groundwater. In WWTPs, concentrations from 0.14 microg/L to several micrograms per liter were observed for all substances, except CTMT, which was detected at lower concentrations. Loads determined in untreated and treated wastewater indicated that removal of the potential markers in WWTPs is negligible; only BTri was partly eliminated (average 33%). In lakes, five compounds, CBZ, DiOH-CBZ, FAA, AAA, and BTri, were consistently detected in concentrations of 2 to 70 ng/L, 3 to 150 ng/L, less than the limit of quantification to 30 ng/L, 2 to 80 ng/L, and 11 to 920 ng/L, respectively. Mean per capita loads in the outflows of the lakes suggested possible dissipation in surface waters, especially of AAA and FAA. Nevertheless, concentrations of CBZ, DiOH-CBZ, and BTri correlated with the actual anthropogenic burden of the lakes by domestic wastewater, indicating that these compounds are suitable for quantification of wastewater contamination in lakes. Marker candidates were also detected in a number of groundwater samples. Carbamazepine concentrations up to 42 ng/L were observed in aquifers with significant infiltration of river water, receiving considerable wastewater discharges from WWTPs. Concentration ratios between compounds indicated some elimination of BTri and DiOH-CBZ during subsurface passage or in groundwater, while CBZ and PMD appeared to be more stable and thus are promising wastewater markers for groundwater. The wastewater burden in groundwater, estimated with the markers CBZ and PMD

  15. Construction and Testing of Broadband High Impedance Ground Planes (HIGPS) for Surface Mount Antennas

    Science.gov (United States)

    2008-03-01

    mushrooms (with side lengths of 7.6mm). Larger mushrooms (with side lengths of 16mm) were located to the edges of the substrate . The resulting...thickness and substrate permittivity are two of the main design parameters. But these parameters have production constraints, since they are ordered off...plane designs as a meta- substrate for a broadband bow-tie antenna were presented. Consequently, the high impedance ground plane provided a suitable

  16. Ground state bands of the E(5) and X(5) critical symmetries obtained from Davidson potentials through a variational procedure

    Energy Technology Data Exchange (ETDEWEB)

    Bonatsos, Dennis; Lenis, D.; Minkov, N.; Petrellis, D.; Raychev, P.P.; Terziev, P.A

    2004-03-25

    Davidson potentials of the form {beta}{sup 2}+{beta}{sub 0}{sup 4}/{beta}{sup 2}, when used in the original Bohr Hamiltonian for {gamma}-independent potentials bridge the U(5) and O(6) symmetries. Using a variational procedure, we determine for each value of angular momentum L the value of {beta}{sub 0} at which the derivative of the energy ratio R{sub L}=E(L)/E(2) with respect to {beta}{sub 0} has a sharp maximum, the collection of R{sub L} values at these points forming a band which practically coincides with the ground state band of the E(5) model, corresponding to the critical point in the shape phase transition from U(5) to O(6). The same potentials, when used in the Bohr Hamiltonian after separating variables as in the X(5) model, bridge the U(5) and SU(3) symmetries, the same variational procedure leading to a band which practically coincides with the ground state band of the X(5) model, corresponding to the critical point of the U(5) to SU(3) shape phase transition. A new derivation of the Holmberg-Lipas formula for nuclear energy spectra is obtained as a by-product.

  17. Ground State Bands of the E(5) and X(5) Critical Symmetries Obtained from Davidson Potentials through a Variational Procedure

    CERN Document Server

    Bonatsos, D; Minkov, N; Petrellis, D; Raychev, P P; Terziev, P A; Bonatsos, Dennis

    2004-01-01

    Davidson potentials of the form $\\beta^2 +\\beta_0^4/\\beta^2$, when used in the original Bohr Hamiltonian for $\\gamma$-independent potentials bridge the U(5) and O(6) symmetries. Using a variational procedure, we determine for each value of angular momentum $L$ the value of $\\beta_0$ at which the derivative of the energy ratio $R_L=E(L)/E(2)$ with respect to $\\beta_0$ has a sharp maximum, the collection of $R_L$ values at these points forming a band which practically coincides with the ground state band of the E(5) model, corresponding to the critical point in the shape phase transition from U(5) to O(6). The same potentials, when used in the Bohr Hamiltonian after separating variables as in the X(5) model, bridge the U(5) and SU(3) symmetries, the same variational procedure leading to a band which practically coincides with the ground state band of the X(5) model, corresponding to the critical point of the U(5) to SU(3) shape phase transition. A new derivation of the Holmberg-Lipas formula for nuclear energy ...

  18. Surface grafted polymer brushes: potential applications in dengue biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Baratela, Fernando Jose Costa; Higa, Olga Zazuco, E-mail: ozahiga@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Faria, Henrique Antonio Mendonca de; Queiroz, Alvaro Antonio Alencar de, E-mail: alencar@unifei.edu.br [Universidade Federal de Itajuba (UNIFEI), Itajuba, MG (Brazil). Instituto de Fisica e Quimica

    2013-07-01

    A polymer brush membrane-based ultrasensitive biosensor for dengue diagnosis was constructed using poly(hydroxyethyl methacrylate) (PHEMA) brushes immobilized onto low density polyethylene (LDPE) films. LDPE surface films were initially modified by Ar{sup +} ion irradiation to activate the polymer surface. Subsequently, graft polymerization of 2-hydroxyethyl methacrylate onto the activated LDPE surface was carried out under aqueous conditions to create patterned polymer brushes of PHEMA. The grafted PHEMA brushes were characterized by Fourier transform-infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and contact angle analysis. The SEM observations showed that selective surface activation with Ar+ implantation and graft polymerization on the selectively activated surface had occurred. The PHEMA brushes were electrically characterized in the presence of concentrations of human immunoglobulin (IgG). The proposed amperometric biosensor was successfully used for determination of IgG in physiologic samples with excellent responses. (author)

  19. The potentialities of ground-penetrating radar in the engineering geology using the radars GROT-12 and GROT-12E

    Science.gov (United States)

    Volkomirskaya, Liudmila; Gulevich, Oxana; Musalev, Dmitri

    2013-04-01

    The potentialities of ground-penetrating radar in the engineering geology using the radars GROT-12 and GROT-12E L.B. Volkomirskaya(1,2), O.A. Gulevich(1,2), D.N. Musalev(3) 1. IZMIRAN, 142190, Russia, Moscow, Troitsk, Kalugskoe 4 2. ZAO Timer, 142190, Russia, Moscow, Troitsk, Lesnaya str. 4B 3. OAO Belgorchemprom, Republic of Belarus, Minsk, Masherov str. 17 The article presents the potentialities of ground-penetrating radar in the engineering geology on the basis of the latest modifications of the GPR "GROT": the low-frequency GPR GROT-12 and the high-frequency GPR GROT-12E. The article gives technical specifications of the GPRs GROT-12 and GROT-12E and their particular characteristics that define them from analogues. The solutions of direct problems of ground penetrating radar on the basis of Maxwell's equations in general formulation with given wide-band signal source are confronted to experimental data received from different fields of the engineering geology, for example: 1. To secure mining in salt mines the method was adapted to locate in the working layers the investigating boreholes, fault lines, borders of displacement and blowout of productive layers, as well as working pits without access. 2. To monitor the reinforced concrete structures of airport runways the technology was worked out to collect and process GPR data so as to locate communications under the runways and examine basement condition. 3. To carry out the reconstruction of buildings and pre-project engineering geological works the GPR shooting technology was improved to process the examinations of the bearing capacity of soils and to locate lost communications. 4. To perform ecological monitoring of abandoned mines the technology of the GPR data collecting and processing was developed to assess the conditions of stowage materials in mouths of destroyed vertical mine shafts, the location of inclined mine shafts, the determination of hollow spaces and thinning zones, the localization of ground

  20. Land and natural resource information and some potential environmental effects of surface mining of coal in the Gillette area, Wyoming

    Science.gov (United States)

    Keefer, William Richard; Hadley, R.F.

    1976-01-01

    Campbell County, along the east margin of the Powder River Basin in northeastern Wyoming, contains more coal than any other county in the United States. The principal deposit is the Wyodak-Anderson coal bed. The bed is 50-100 feet (15-30 meters) thick over large areas, lies less than 200 feet (60 meters) deep in a north-south trending strip nearly 100 miles (161 kilometers) long and 2-3 miles (3-5 kilometers) wide, and contains an estimated 15 billion tons (13.6 billion metric tons) of sub-bituminous, low-sulfur coal that is presently considered to be accessible to surface mining. Extensive mining of this deposit has the potential for causing a variety of environmental impacts and has been a matter of much public concern and debate in recent years. An integrated program of geologic, hydrologic, geochemical, and related studies by the U.S. Geological Survey in central Campbell County provides basic information about the land and its resources, including (1) characteristics of the landscape, (2) properties of rocks and surface materials, (3) depth and thickness of coal, (4) streamflow, (5) depth to ground water, (6) quality of ground water, (7) sediment yield, (8) concentrations of trace elements in soils, rocks, coal, vegetation, and water, and (9) current land use. The data are used to analyze and predict some of the potential environmental effects of surface mining, such as the extent of land disturbance, nature and degree of landscape modification, and disruption of surface-water and ground-water systems. Advance knowledge and understanding of these and other problems are useful in the planning and regulation of future leasing, mining, reclamation, and related activities.

  1. G.POT: a method for the assessment and mapping of the near-surface geothermal potential

    Science.gov (United States)

    Casasso, Alessandro; Sethi, Rajandrea

    2017-04-01

    Shallow geothermal systems are widely recognised as a valuable technology for the heating and cooling of buildings. The most adopted technology is the Borehole Heat Exchanger (BHE), since it can be installed almost everywhere. However, the economic viability of BHEs depends on the thermal load that can be efficiently exchanged with the ground, i.e. the near-surface geothermal potential. We present the G.POT (Geothermal POTential) method for the assessment of near-surface geothermal potential as a function of the thermal conductivity and capacity of the ground, of its initial temperature, of the thermal resistance of the BHE and of the duration of the sinusoidal thermal load cycle, which reproduces the typical pattern of a thermal load during a heating or a cooling season. The function was calibrated from the results of numerical heat transfer simulations, performed varying the values of the aforementioned parameters over broad ranges. G.POT is a simple mathematical tool which can be easily implemented for the large-scale assessment and mapping of the near-surface geothermal potential for heating or cooling purpose. An example of its application is also shown, and advice is provided on the processing of input parameters. References A. Casasso, R. Sethi, G.POT: A quantitative method for the assessment and mapping of the shallow geothermal potential, Energy 106 (2016) 765-773. A. Casasso, R. Sethi, Assessment and mapping of the shallow geothermal potential in the province of Cuneo (Piedmont, NW Italy), Renewable Energy 102, Part B (2017) 306-315.

  2. A global potential energy surface and dipole moment surface for silane.

    Science.gov (United States)

    Owens, Alec; Yurchenko, Sergei N; Yachmenev, Andrey; Thiel, Walter

    2015-12-28

    A new nine-dimensional potential energy surface (PES) and dipole moment surface (DMS) for silane have been generated using high-level ab initio theory. The PES, CBS-F12(HL), reproduces all four fundamental term values for (28)SiH4 with sub-wavenumber accuracy, resulting in an overall root-mean-square error of 0.63 cm(-1). The PES is based on explicitly correlated coupled cluster calculations with extrapolation to the complete basis set limit, and incorporates a range of higher-level additive energy corrections to account for core-valence electron correlation, higher-order coupled cluster terms, and scalar relativistic effects. Systematic errors in computed intra-band rotational energy levels are reduced by empirically refining the equilibrium geometry. The resultant Si-H bond length is in excellent agreement with previous experimental and theoretical values. Vibrational transition moments, absolute line intensities of the ν3 band, and the infrared spectrum for (28)SiH4 including states up to J = 20 and vibrational band origins up to 5000 cm(-1) are calculated and compared with available experimental results. The DMS tends to marginally overestimate the strength of line intensities. Despite this, band shape and structure across the spectrum are well reproduced and show good agreement with experiment. We thus recommend the PES and DMS for future use.

  3. A global potential energy surface and dipole moment surface for silane

    Energy Technology Data Exchange (ETDEWEB)

    Owens, Alec, E-mail: owens@mpi-muelheim.mpg.de [Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr (Germany); Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London (United Kingdom); Yurchenko, Sergei N.; Yachmenev, Andrey [Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London (United Kingdom); Thiel, Walter [Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr (Germany)

    2015-12-28

    A new nine-dimensional potential energy surface (PES) and dipole moment surface (DMS) for silane have been generated using high-level ab initio theory. The PES, CBS-F12{sup HL}, reproduces all four fundamental term values for {sup 28}SiH{sub 4} with sub-wavenumber accuracy, resulting in an overall root-mean-square error of 0.63 cm{sup −1}. The PES is based on explicitly correlated coupled cluster calculations with extrapolation to the complete basis set limit, and incorporates a range of higher-level additive energy corrections to account for core-valence electron correlation, higher-order coupled cluster terms, and scalar relativistic effects. Systematic errors in computed intra-band rotational energy levels are reduced by empirically refining the equilibrium geometry. The resultant Si–H bond length is in excellent agreement with previous experimental and theoretical values. Vibrational transition moments, absolute line intensities of the ν{sub 3} band, and the infrared spectrum for {sup 28}SiH{sub 4} including states up to J = 20 and vibrational band origins up to 5000 cm{sup −1} are calculated and compared with available experimental results. The DMS tends to marginally overestimate the strength of line intensities. Despite this, band shape and structure across the spectrum are well reproduced and show good agreement with experiment. We thus recommend the PES and DMS for future use.

  4. DEM Development from Ground-Based LiDAR Data: A Method to Remove Non-Surface Objects

    Directory of Open Access Journals (Sweden)

    Maneesh Sharma

    2010-11-01

    Full Text Available Topography and land cover characteristics can have significant effects on infiltration, runoff, and erosion processes on watersheds. The ability to model the timing and routing of surface water and erosion is affected by the resolution of the digital elevation model (DEM. High resolution ground-based Light Detecting and Ranging (LiDAR technology can be used to collect detailed topographic and land cover characteristic data. In this study, a method was developed to remove vegetation from ground-based LiDAR data to create high resolution DEMs. Research was conducted on intensively studied rainfall–runoff plots on the USDA-ARS Walnut Gulch Experimental Watershed in Southeast Arizona. LiDAR data were used to generate 1 cm resolution digital surface models (DSM for 5 plots. DSMs created directly from LiDAR data contain non-surface objects such as vegetation cover. A vegetation removal method was developed which used a slope threshold and a focal mean filter method to remove vegetation and create bare earth DEMs. The method was validated on a synthetic plot, where rocks and vegetation were added incrementally. Results of the validation showed a vertical error of ±7.5 mm in the final DEM.

  5. Temperature rise in objects due to optical focused beam through atmospheric turbulence near ground and ocean surface

    Science.gov (United States)

    Stoneback, Matthew; Ishimaru, Akira; Reinhardt, Colin; Kuga, Yasuo

    2013-03-01

    We consider an optical beam propagated through the atmosphere and incident on an object causing a temperature rise. In clear air, the physical characteristics of the optical beam transmitted to the object surface are influenced primarily by the effect of atmospheric turbulence, which can be significant near the ground or ocean surface. We use a statistical model to quantify the expected power transfer through turbulent atmosphere and provide guidance toward the threshold of thermal blooming for the considered scenarios. The bulk thermal characteristics of the materials considered are used in a thermal diffusion model to determine the net temperature rise at the object surface due to the incident optical beam. These results of the study are presented in graphical form and are of particular interest to operators of high power laser systems operating over large distances through the atmosphere. Numerical examples include a CO2 laser (λ=10.6 μm) with: aperture size of 5 cm, varied pulse duration, and propagation distance of 0.5 km incident on 0.1-mm copper, 10-mm polyimide, 1-mm water, and 10-mm glass/resin composite targets. To assess the effect of near ground/ocean laser propagation, we compare turbulent (of varying degrees) and nonturbulent atmosphere.

  6. Six-dimensional potential energy surface of the dissociative chemisorption of HCl on Au(111) using neural networks

    Institute of Scientific and Technical Information of China (English)

    LIU TianHui; FU BiNa; ZHANG Dong H

    2014-01-01

    We constructed a six-dimensional potential energy surface(PES)for the dissociative chemisorption of HCl on Au(111)using the neural networks method based on roughly 70000 energies obtained from extensive density functional theory(DFT)calculations.The resulting PES is accurate and smooth,based on the small fitting errors and good agreement between the fitted PES and the direct DFT calculations.Time-dependent wave packet calculations show that the potential energy surface is very well converged with respect to the number of DFT data points,as well as to the fitting process.The dissociation probabilities of HCl initially in the ground rovibrational state from six-dimensional quantum dynamical calculations are quite diferent from the four-dimensional fixed-site calculations,indicating it is essential to perform full-dimensional quantum dynamical studies for the title molecule-surface interaction system.

  7. Geochemical processes in ground water resulting from surface mining of coal at the Big Sky and West Decker Mine areas, southeastern Montana

    Science.gov (United States)

    Clark, D.W.

    1995-01-01

    A potential hydrologic effect of surface mining of coal in southeastern Montana is a change in the quality of ground water. Dissolved-solids concen- trations in water in spoils aquifers generally are larger than concentrations in water in the coal aquifers they replaced; however, laboratory experiments have indicated that concentrations can decrease if ground water flows from coal-mine spoils to coal. This study was conducted to determine if decreases in concentrations occur onsite and, if so, which geochemical processes caused the decreases. Solid-phase core samples of spoils, unmined over- burden, and coal, and ground-water samples were collected from 16 observation wells at two mine areas. In the Big Sky Mine area, changes in ground- water chemistry along a flow path from an upgradient coal aquifer to a spoils aquifer probably were a result of dedolomitization. Dissolved-solids concentrations were unchanged as water flowed from a spoils aquifer to a downgradient coal aquifer. In the West Decker Mine area, dissolved-solids concentrations apparently decreased from about 4,100 to 2,100 milligrams per liter as water moved along an inferred flow path from a spoils aquifer to a downgradient coal aquifer. Geochemical models were used to analyze changes in water chemistry on the basis of results of solid-phase and aqueous geochemical characteristics. Geochemical processes postulated to result in the apparent decrease in dissolved-solids concentrations along this inferred flow path include bacterial reduction of sulfate, reverse cation exchange within the coal, and precipitation of carbonate and iron-sulfide minerals.

  8. Evaluation of arsenic and other physico-chemical parameters of surface and ground water of Jamshoro, Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Baig, Jameel Ahmed, E-mail: jab_mughal@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kazi, Tasneem Gul, E-mail: tgkazi@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Arain, Muhammad Balal, E-mail: bilal_KU2004@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Afridi, Hassan Imran, E-mail: hassanimranafridi@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kandhro, Ghulam Abbas, E-mail: gakandhro@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Sarfraz, Raja Adil, E-mail: rajaadilsarfraz@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Jamal, Muhammad Khan, E-mail: mkhanjamali@yahoo.com [Government Degree College Usta Muhammad, Balochistan 08300 (Pakistan); Shah, Abdul Qadir, E-mail: aqshah07@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)

    2009-07-30

    Arsenic contamination in water has caused severe health problems around the world. The purpose of this study was to evaluate the geological and anthropogenic aspects of As pollution in surface and groundwater resources of Jamshoro Sindh, Pakistan. Hydride generator atomic absorption spectrophotometry (HG-AAS) is employed for the determination of arsenic in water samples, with detection limit of 0.02 {mu}g l{sup -1}. Arsenic concentrations in surface and underground water range from 3.0 to 50.0, and 13 to 106 {mu}g l{sup -1}, respectively. In most of the water samples As levels exceeded the WHO provisional guideline values 10 {mu}g l{sup -1}. The high level of As in under study area may be due to widespread water logging from Indus river irrigation system which causes high saturation of salts in this semi-arid region and lead to enrichment of As in shallow groundwater. Among the physico-chemical parameters, electrical conductivity, Na{sup +}, K{sup +}, and SO{sub 4}{sup 2-} were found to be higher in surface and ground water, while elevated levels of Ca{sup 2+} and Cl{sup -} were detected only in ground water than WHO permissible limit. The high level of iron was observed in ground water, which is a possible source of As enrichment in the study area. The multivariate technique (cluster analysis) was used for the elucidation of high, medium and low As contaminated areas. It may be concluded that As originate from coal combustion at brick factories and power generation plants, and it was mobilized promotionally by the alkaline nature of the understudy groundwater samples.

  9. Geochemistry of the surface and ground waters of the upper bassin of the river Llobregat

    Directory of Open Access Journals (Sweden)

    Freixes, A.

    1996-12-01

    Full Text Available In this work the main geochemical characteristics of the surface and ground waters of the Upper basin of the River Llobregat are described and, discussed. The water samples analysed reveal sharply contrasting characteristics. In both the Fonts del Llobregat and River Bastareny catchments, calcium bicarbonated waters with a low mineral content clearly predominate. However, in the catchment of the River Arija, although the waters of the upper course and the main tributaries are also calcium bicarbonated, it is worth noting that at the confluence with the River Llobregat calcium sulphated water is found. The catchment of the River Saldes shows a greater heterogeneity, with calcium bicarbonated, sodium chloridized and calcium sulphated waters, and thus at the confluence with the River Llobregat the water is sodium-calcium bicarbonated-sulphated. Principal components analysis enables us to arrive at a synthesis which clearly explains these characteristics. These results are fundamentally interpreted on the basis of the lithologies drained by the different watercourses.

    [es] En el presente estudio se presentan y discuten las principales características geoquímicas de las aguas superficiales y subterráneas de la Alta cuenca del río Llobregat hasta la entrada del río al embalse de La Baells. El conjunto de aguas analizadas presentan características muy contrastadas. Así, tanto en la subcuenca de las fuentes del Llobregat como en la del río Bastareny predominan las aguas bicarbonatadas cálcicas poco mineralizadas. En la subcuenca del río Arija, sí bien las aguas del curso alto y las de los principales afluentes también son bicarbonatadas cálcicas, destaca el hecho de que en la confluencia con el río Llobregat el agua es sulfatada cálcica. La subcuenca del río Saldes es la que presenta una mayor heterogeneidad, con aguas bicarbonatadas cálcicas, cloruradas sódicas y sulfatadas cálcicas, las cuales provocan que en la confluencia

  10. Surface-water, water-quality, and ground-water assessment of the Municipio of Carolina, Puerto Rico, 1997-99

    Science.gov (United States)

    Rodríguez-Martínez, Jesús; Gómez-Gómez, Fernando; Santiago-Rivera, Luis; Oliveras-Feliciano, M. L.

    2001-01-01

    concentrations above the water-quality goal established by the Puerto Rico Environmental Quality Board (Junta de Calidad Ambiental de Puerto Rico) for inland surface waters. Sources of fecal contamination may include: illegal discharge of sewage to storm-water drains, malfunctioning sanitary sewer ejectors, clogged and leaking sewage pipes, septic tank leakage, unfenced livestock, and runoff from livestock pens. Long-term fecal coliform data at two sampling stations, Quebrada Blasina in Carolina and the Rio Grande de Loiza, downstream from the town of Trujillo Alto, indicate that the sanitary quality of Quebrada Blasina is and has generally been poor for more than a decade. The sanitary quality of the Rio Grande de Loiza has generally been in compliance with the water-quality goal standard fecal coliform concentrations established in July 1990 by the Puerto Rico Environmental Quality Board. Geologic, topographic, soil, hydrogeologic, and streamflow data were used to divide the municipio of Carolina into five hydrogeologic terranes. This integrated database was then used to evaluate the ground-water potential of each hydrogeologic terrane. Analysis suggests that areas with slopes greater than 15 degrees have relatively low ground-water development potential. Fractures may be locally important in enhancing the water-bearing properties in the hydrogeologic terranes containing igneous rocks. Potentiometric-surface elevations recorded in piezometers installed in the coastal area during this study were used to define ground-water flow directions in the hydrogeologic terranes composed of coastal plain clastic and limestone units. The resultant potentiometric map indicates that the coastal plain aquifer and streams in the lowland parts of the municipio of Carolina are hydraulically connected. The potentiometric map also indicates that ground-water discharge to the Rio Grande de Loiza, downstream from highway PR-3, has been enhanced by dredging of the streambed for

  11. Path integral molecular dynamics calculations of the H6+ and D6+ clusters on an ab initio potential energy surface

    Science.gov (United States)

    Kakizaki, Akira; Takayanagi, Toshiyuki; Shiga, Motoyuki

    2007-11-01

    Path integral molecular dynamics simulations for the H6+ and D6+ cluster cations have been carried out in order to understand the floppy nature of their molecular structure due to quantum-mechanical fluctuation. A full-dimensional analytical potential energy surface for the ground electronic state of H6+ has been developed on the basis of accurate ab initio electronic structure calculations at the CCSD(T)/cc-pVTZ level. It is found that the outer H 2(D 2) nuclei rotate almost freely and that the probability density distributions of the central H 2(D 2) nuclei show strong spatial delocalization.

  12. Hydrochemical assessments of surface Nile water and ground water in an industry area – South West Cairo

    Directory of Open Access Journals (Sweden)

    Mona El-Sayed

    2015-09-01

    The data obtained were used for mathematical calculations of some parameters such as sodium adsorption ratio (SAR, sodium percentage (Na%, and the suitability of water samples for drinking, domestic, and irrigation purposes was evaluated. The results indicate that most studied surface Nile water samples show excellent to good categories and are suitable for drinking and irrigation. Most studied ground water samples are not suitable for drinking and need treatment for irrigation; few samples are not suitable for any purpose because of pollution from different sources in this area.

  13. Different Multifractal Scaling of the 0 cm Average Ground Surface Temperature of Four Representative Weather Stations over China

    Directory of Open Access Journals (Sweden)

    Lei Jiang

    2013-01-01

    Full Text Available The temporal scaling properties of the daily 0 cm average ground surface temperature (AGST records obtained from four selected sites over China are investigated using multifractal detrended fluctuation analysis (MF-DFA method. Results show that the AGST records at all four locations exhibit strong persistence features and different scaling behaviors. The differences of the generalized Hurst exponents are very different for the AGST series of each site reflecting the different scaling behaviors of the fluctuation. Furthermore, the strengths of multifractal spectrum are different for different weather stations and indicate that the multifractal behaviors vary from station to station over China.

  14. Contamination of rural surface and ground water by endosulfan in farming areas of the Western Cape, South Africa

    Directory of Open Access Journals (Sweden)

    London Leslie

    2003-03-01

    Full Text Available Abstract Background In South Africa there is little data on environmental pollution of rural water sources by agrochemicals. Methods This study investigated pesticide contamination of ground and surface water in three intensive agricultural areas in the Western Cape: the Hex River Valley, Grabouw and Piketberg. Monitoring for endosulfan and chlorpyrifos at low levels was conducted as well as screening for other pesticides. Results The quantification limit for endosulfan was 0.1 μg/L. Endosulfan was found to be widespread in ground water, surface water and drinking water. The contamination was mostly at low levels, but regularly exceeded the European Drinking Water Standard of 0.1 μg/L. The two most contaminated sites were a sub-surface drain in the Hex River Valley and a dam in Grabouw, with 0.83 ± 1.0 μg/L (n = 21 and 3.16 ± 3.5 μg/L (n = 13 average endosulfan levels respectively. Other pesticides including chlorpyrifos, azinphos-methyl, fenarimol, iprodione, deltamethrin, penconazole and prothiofos were detected. Endosulfan was most frequently detected in Grabouw (69% followed by Hex River (46% and Piketberg (39%. Detections were more frequent in surface water (47% than in groundwater (32% and coincided with irrigation, and to a lesser extent, to spraying and trigger rains. Total dietary endosulfan intake calculated from levels found in drinking water did not exceed the Joint WHO/FAO Meeting on Pesticide Residues (JMPR criteria. Conclusion The study has shown the need for monitoring of pesticide contamination in surface and groundwater, and the development of drinking water quality standards for specific pesticides in South Africa.

  15. Bacteriophages reduce experimental contamination of hard surfaces, tomato, spinach, broccoli, and ground beef by Escherichia coli O157:H7.

    Science.gov (United States)

    Abuladze, Tamar; Li, Manrong; Menetrez, Marc Y; Dean, Timothy; Senecal, Andre; Sulakvelidze, Alexander

    2008-10-01

    A bacteriophage cocktail (designated ECP-100) containing three Myoviridae phages lytic for Escherichia coli O157:H7 was examined for its ability to reduce experimental contamination of hard surfaces (glass coverslips and gypsum boards), tomato, spinach, broccoli, and ground beef by three virulent strains of the bacterium. The hard surfaces and foods contaminated by a mixture of three E. coli O157:H7 strains were treated with ECP-100 (test samples) or sterile phosphate-buffered saline buffer (control samples), and the efficacy of phage treatment was evaluated by comparing the number of viable E. coli organisms recovered from the test and control samples. Treatments (5 min) with the ECP-100 preparation containing three different concentrations of phages (10(10), 10(9), and 10(8) PFU/ml) resulted in statistically significant reductions (P = E. coli O157:H7 organisms recovered from the glass coverslips. Similar treatments resulted in reductions of 100%, 95%, and 85%, respectively, in the number of E. coli O157:H7 organisms recovered from the gypsum board surfaces; the reductions caused by the two most concentrated phage preparations were statistically significant. Treatment with the least concentrated preparation that elicited significantly less contamination of the hard surfaces (i.e., 10(9) PFU/ml) also significantly reduced the number of viable E. coli O157:H7 organisms on the four food samples. The observed reductions ranged from 94% (at 120 +/- 4 h posttreatment of tomato samples) to 100% (at 24 +/- 4 h posttreatment of spinach samples). The data suggest that naturally occurring bacteriophages may be useful for reducing contamination of various hard surfaces, fruits, vegetables, and ground beef by E. coli O157:H7.

  16. ENVIRONMENTAL SAFETY IMPROVEMENT OF SURFACE AND GROUND WATER CONTAMINATION AT THE AIRPORT AREA

    Directory of Open Access Journals (Sweden)

    Svitlana Madzhd

    2016-11-01

    Full Text Available Purpose: Taking into account that the airport "Kyiv" is located in one of the central districts of Kyiv and does not have clearly established sanitary protection zones, the problem of environmental pollution is topical and requires monitoring and research. In order to improve environmental compliance we made assessment of superficial and ground water quality in airport zone. Methods: Water quality was estimated by the biotesting method, hydrochemical analysis, and by oil products detection method. Results We performed analysis of wastewaters of airport “Kyiv” and superficial waters of river Nyvka. The samples took place: above the airport drainage, in the drainage place and below drainage place. We conducted assessment of ground waters, which are sources of water supply, on different distance from an airport (20 m, 500 m, 1000 m, 1500 min. Results of hydrochemical investigations of river indicated excess of nitrogen compounds content compare to regulatory discharge. Thus, it was defined excess of ammonia nitrogen in wastewaters in three times and in place of dispersion – in ten times; the content of nitrite nitrogen in the river sample after discharge exceeds in 22 times norm. Analysis of drinking water in airport zone has showed extremely high level of pollution by nitrite nitrogen exceeding norm in 7-17 times. After analysis it was defined high level of river pollution by oil products (in 26-32 times higher than MPC, and ground water in 1, 5-2 times. Results of biotesting confirmed data of hydrochemical investigations of superficial water state (acute toxicity was observed in drainage area and in place of drainage dispersion. Discussion: Increased content of nitrite indicates the strengthening of decomposition process of organic matter in conditions of slower oxidation of NO into NO. This parameter is major sanitary indicator which indicates pollution of water body. High content of such specific pollutant for aviation transport

  17. Influence of the underlying surface on the antenna system of the ground penetrating radar

    Science.gov (United States)

    Balzovsky, E. V.; Buyanov, Yu I.; Shipilov, S. E.

    2017-08-01

    Simulation results of the antenna system of the radar of subsurface sounding intended for contactless investigation of the road condition are presented. The elements of the antenna system of ground penetrating radar with extended bandwidth made as a combination of electric and magnetic type radiators have been designed. The transmission coefficient between the elements of the antenna array determining their mutual influence has been calculated. Despite the close arrangement of the elements in the array, the level of mutual influence of the elements is not critical. The developed antenna array can be used both for excitation with short ultrawideband pulses and for frequency steering in the range of 0.8-4 GHz.

  18. Assessment of volatile organic compounds in surface water at Canal Creek, Aberdeen Proving Ground, Maryland, November 1999-September 2000

    Science.gov (United States)

    Phelan, Daniel J.; Olsen, Lisa D.; Senus, Michael P.; Spencer, Tracey A.

    2001-01-01

    The purpose of this report is to describe the occurrence and distribution of volatile organic compounds in surface-water samples collected by the U.S. Geological Survey in the Canal Creek area of Aberdeen Proving Ground, Maryland, from November 1999 through September 2000. The report describes the differences between years with below normal and normal precipitation, the effects of seasons, tide stages, and location on volatile organic compound concentrations in surface water, and provides estimates of volatile organic concentration loads to the tidal Gunpowder River. Eighty-four environmental samples from 20 surface-water sites were analyzed. As many as 13 different volatile organic compounds were detected in the samples. Concentrations of volatile organic compounds in surface-water samples ranged from below the reporting limit of 0.5 micrograms per liter to a maximum of 50.2 micrograms per liter for chloroform. Chloroform was detected most frequently, and was found in 55 percent of the environmental samples that were analyzed for volatile organic compounds (46 of 84 samples). Carbon tetrachloride was detected in 56 percent of the surface-water samples in the tidal part of the creek (34 of 61 samples), but was only detected in 3 of 23 samples in the nontidal part of the creek. 1,1,2,2-Tetrachloroethane was detected in 43 percent of the tidal samples (26 of 61 samples), but was detected at only two nontidal sites and only during November 1999. Three samples were collected from the tidal Gunpowder River about 300 feet from the mouth of Canal Creek in May 2000, and none of the samples contained volatile organic compound concentrations above detection levels. Volatile organic compound concentrations in surface water were highest in the reaches of the creek adjacent to the areas with the highest known levels of ground-water contamination. The load of total volatile organic compounds from Canal Creek to the Gunpowder River is approximately 1.85 pounds per day (0

  19. Identification Of Ground Water Potential Zones In Tamil Nadu By Remote Sensing And GIS Technique

    Directory of Open Access Journals (Sweden)

    T. Subramani

    2014-12-01

    Full Text Available A case study was conducted to find out the groundwater potential zones in Salem, Erode and Namakkal districts, Tamil Nadu, India with an aerial extent of 360.60 km2 . The thematic maps such as geology, geomorphology, soil hydrological group, land use / land cover and drainage map were prepared for the study area. The Digital Elevation Model (DEM has been generated from the 10 m interval contour lines (which is derived from SOI, Toposheet 1:25000 scale and obtained the slope (% of the study area. The groundwater potential zones were obtained by overlaying all the thematic maps in terms of weighted overlay methods using the spatial analysis tool in Arc GIS 9.3. During weighted overlay analysis, the ranking has been given for each individual parameter of each thematic map and weights were assigned according to the influence such as soil −25%, geomorphology − 25%, land use/land cover −25%, slope − 15%, lineament − 5% and drainage / streams − 5% and find out the potential zones in terms of good, moderate and poor zones with the area of 49.70 km2 , 261.61 km2 and 46.04 km2 respectively. The potential zone wise study area was overlaid with village boundary map and the village wise groundwater potential zones with three categories such as good, moderate and poor zones were obtained. This GIS based output result was validated by conducting field survey by randomly selecting wells in different villages using GPS instruments. The coordinates of each well location were obtained by GPS and plotted in the GIS platform and it was clearly shown that the well coordinates were exactly seated with the classified zones.

  20. Road impacts on the Baca National Wildlife Refuge, Colorado, with emphasis on effects to surface and shallow ground-water hydrology : a literature review

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A review of published research on unpaved road effects on surface-water and shallow ground-water hydrology was undertaken to assist the Baca National Wildlife...

  1. Estimated potentiometric surface by D'Agnese and others (1998), for the Death Valley regional ground-water flow system study, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — D'Agnese and others (1998) developed a potentiometric surface to conceptualize the regional ground-water flow system and to construct numerical flow models of the...

  2. AATSR Land Surface Temperature Product Validation Using Ground Measurements in China and Implications for SLSTR

    Science.gov (United States)

    Zhou, Ji; Zmuda, Andy; Desnos, Yves-Louis; Ma, Jin

    2016-08-01

    Land surface temperature (LST) is one of the most important parameters at the interface between the earth's surface and the atmosphere. It acts as a sensitive indicator of climate change and is an essential input parameter for land surface models. Because of the intense variability at different spatial and temporal scales, satellite remote sensing provides the sole opportunity to acquire LSTs over large regions. Validation of the LST products is an necessary step before their applications conducted by scientific community and it is essential for the developers to improve the LST products.

  3. Potential function of the internal rotation of a methacrolein molecule in the ground ( S 0) electronic state

    Science.gov (United States)

    Koroleva, L. A.; Krasnoshchekov, S. V.; Matveev, V. K.; Pentin, Yu. A.

    2016-08-01

    The structural parameters of s- trans- and s- cis-isomers of a methacrolein molecule in the ground ( S 0) electronic state are determined by means of MP2 method with the cc-pVTZ basis set. Kinematic factor F(φ) is expanded in a Fourier series. The potential function of internal rotation (PFIR) of methacrolein in this state is built using experimental frequencies of transitions of the torsional vibration of both isomers, obtained from an analysis of the vibrational structure of the high-resolution UV spectrum with allowance for the geometry and difference between the energy (Δ H) of the isomers. It is shown that the V n parameters of the potential function of internal rotation of the molecule, built using the frequencies of the transition of the torsional vibrations of s- trans- and s- cis-isomers of the methacrolein molecule, determined from vibrational structure of the high-resolution UV spectrum and the FTIR spectrum, are close.

  4. Accurate internuclear potential energy functions for the ground electronic states of NeH+ and ArH+

    Science.gov (United States)

    Coxon, John A.; Hajigeorgiou, Photos G.

    2016-12-01

    All pure rotational and vibrational-rotational spectroscopic line positions available on the ground X1Σ+ electronic states of the rare gas hydride cations NeH+ and ArH+ have been employed in weighted least-squares direct fits to the potential energy functions, together with auxiliary functions describing breakdown of the Born-Oppenheimer approximation. All radial functions are represented by compact analytical models, and the spectroscopic line positions are reproduced to within the associated experimental uncertainties by the quantum-mechanical eigenvalues of the derived Hamiltonians. The potential energy functions are constrained to approach the theoretical radial behavior at long-range. Accurate vibrational term values and rotational and centrifugal distortion constants are provided for all stable isotopologues of NeH+ and ArH+ included in the least-squares fits.

  5. 3D simulation of near-fault strong ground motion:comparison between surface rupture fault and buried fault

    Institute of Scientific and Technical Information of China (English)

    Liu Qifang; Yuan Yifan; Jin Xing

    2007-01-01

    In this paper,near-fault strong ground motions caused by a surface rupture fault(SRF)and a buried fault(BF) are numerically simulated and compared by using a time-space-decoupled,explicit finite element method combined with a multi-transmitting formula(MTF) of an artificial boundary.Prior to the comparison,verification of the explicit element method and the MTF is conducted.The comparison results show that the final dislocation of the SRF is larger than the BF for the same stress drop on the fault plane.The maximum final dislocation occurs on the fault upper line for the SRF;however,for the BF,the maximum final dislocation is located on the fault central part.Meanwhile,the PGA,PGV and PGD of long period ground motions(≤1 Hz)generated by the SRF are much higher than those of the BF in the near-fault region.The peak value of the velocity pulse generated by the SRF is also higher than the BF.Furthermore,it is found that in a very narrow region along the fault trace,ground motions caused by the SRF are much higher than by the BF.These results may explain why SRFs almost always cause heavy damage in near-fault regions compared to buried faults.

  6. Activities of the Commission for Ground Surface Protection against Mining Damage in the first quarter of 1985. [Poland

    Energy Technology Data Exchange (ETDEWEB)

    Chroszcz, A.

    1985-01-01

    Five meetings of the Commission held from January to March 1985 are reported. Underground coal mining in the safety pillar of Bytom was discussed in the light of rock bursts and fatal accidents in the Dymitrow mine. Three coal mines remove the safety pillar: Dymitrow, Szombierki and Rozbark. The Commission discussed: replacing longwall mining with caving by longwall mining with hydraulic stowing, using packings with reduced settling, reducing concentration of mining operations in the area of Bytom center, coordination of underground mining by 3 mines (coordination of mining order, thickness of coal slices or coal seams, concentration of longwall mining in seams with reduced hazards of rock bursts, methods for protection of buildings and industrial plants at the ground surface against ground deformation. The Commission also discussed program of coal mining with hydraulic stowing in the safety pillar of the Batory Steelworks, the Hajduki chemical plant and Chorzow (order of mining, schemes for slice mining, forecasting ground subsidence, methods for protection against mining damage), underground mining with caving or stowing in safety pillars of the Miechowice and Karb mines under Bytom, new regulations on geodetic surveys in underground coal mines.

  7. Determination of barium in surface and ground waters at Centro Experimental Aramar area

    Energy Technology Data Exchange (ETDEWEB)

    Matoso, Erika, E-mail: ematoso@hotmail.com [Centro Tecnologico da Marinha em Sao Paulo (CEA/CTMS), Ipero, SP (Brazil). Centro Experimental Aramar; Cadore, Solange, E-mail: cadore@iqm.unicamp.br [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Instituto de Quimica. Departamento de Quimica Analica

    2015-07-01

    Barium can be found in waters up to 1 mg L{sup -1} and came from natural sources such as sedimentary rocks erosion rich in feldspar and barite. Also anthropogenic activities can release this element such as oil and gas industry, agricultural defensives, chemical industry and waste disposal. At high doses, barium can be harmful to human central nervous system and can also cause high blood pressure, heart problems, fatigue and anxiety. The water potability defined by Brazilian's Ministry of Healthy sets barium concentration up to 0.7 mg L{sup -1} and official regulation defines the same limit of this element to superficial waters (according CONAMA resolution 357/2005) and ground waters (Sao Paulo state regulation). In this work, barium was analyzed monthly in superficial waters from 4 different sampling locations, located in a ratio of 10-km-long from Centro Experimental Aramar (CEA) at Ipanema River, during one year, in order to evaluate the river in different conditions (seasons, temperature and rain period). The ground water was collected every six months. The analytical technique applied was ICP OES and the method conditions were optimized: wavelength, linearity, signal background ratio, detection and quantification limits. Data obtained in this work will contribute to evaluate the presence of barium at CEA region and nearby in order to compare it with current Brazilian regulations. (author)

  8. Tracing nitrate pollution sources and transformation in surface- and ground-waters using environmental isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yan [Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Fadong, E-mail: lifadong@igsnrr.ac.cn [Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); Zhang, Qiuying [Center for Agricultural Resources Research, Chinese Academy of Sciences, Shijiazhuang 050021 (China); Li, Jing [Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); Liu, Qiang [Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China)

    2014-08-15

    Water pollution in the form of nitrate nitrogen (NO{sub 3}{sup −}–N) contamination is a major concern in most agricultural areas in the world. Concentrations and nitrogen and oxygen isotopic compositions of nitrate, as well as oxygen and deuterium isotopic compositions of surface and groundwater from a typical irrigated region in the North China Plain (NCP) collected from May to October in 2012 were analyzed to examine the major nitrate sources and transformations. Concentrations of NO{sub 3}{sup −}–N ranged from 0.2 to 29.6 mg/L (mean of 11.2 mg/L) in surface water, and from 0.1 to 19.4 mg/L (mean of 2.8 mg/L) in groundwater. Approximately 46.7% of the surface water samples and 10% of the groundwater samples exceeded the World Health Organization (WHO) drinking water standard for NO{sub 3}{sup −}–N. Surface water samples that exceeded the standard were collected mainly in the dry season (May and October), while groundwater samples that exceeded the standard were collected in the wet season (June). Overall, the highest nitrate levels were observed in surface water in May and in groundwater in June, indicating that fertilizer application, precipitation, and irrigation strongly influence the NO{sub 3}{sup −}–N concentrations. Analyses of isotopic compositions suggest that the main sources of nitrate are nitrification of fertilizer and sewage in surface water, in contrast, mineralization of soil organic N and sewage is the groundwater sources during the dry season. When fertilizers are applied, nitrate will be transported by precipitation through the soil layers to the groundwater in the wet season (June). Denitrification only occurred in surface water in the wet season. Attempts should be made to minimize overuse of nitrogen fertilizers and to improve nitrogen use efficiency in irrigated agricultural regions. - Highlights: • Nitrate sources in surface and groundwater were identified by multiple isotopes. • Nitrate pollution displayed obvious

  9. Be(1010): A test ground for surface electron-phonon coupling

    Science.gov (United States)

    Tang, Shu-Jung; Sprunger, Philip; Plummer, Ward; Yang, Wanli; Brouet, Veronique; Zhou, Xingjiang; Shen, Zhi-Xun

    2003-03-01

    The electron-phonon coupling on the Be(10bar10) surface has been investigated with high-resolution photoemission examining temperature dependence and dispersion distortion near the Fermi energy of the two zone boundary surface states. Two surface states (S1 and S2) coexist in a large gap in the bulk projection at the surface zone boundary barA. S1 is localized near the surface in the middle of the gap while S2 is near the bottom band edge and penetrates into the bulk. Using both a Debye and Einstein model to fit the temperature-dependent surface state line width produces an electron-phonon coupling strength with parameters, λ _S1 = 0.647 and λ _S2 = 0.491, more than two times larger than the bulk value, λ _bulk = 0.24. S2 data was measured with a 3D Debye model but the S1 data required an Einstein model with an optical phonon at energy 64 meV. Direct 2D images of the dispersion of the S1 state show dramatic distortion of the electron band dispersion within 64 meV of the Fermi energy. This data is used to extract the real and imaginary parts of the self-energy. Founded by NSF DMR-0105232 and Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Dept. of Energy under contract DE-AC05-00OR22725

  10. Potential areas of ground-water discharge in the Basin and Range carbonate-rock aquifer system, White Pine County, Nevada, and adjacent parts of Nevada and Utah

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data represent potential areas of ground-water discharge for selected hydrographic areas in eastern Nevada and western Utah. The data are based on phreatophyte...

  11. High resolution surface solar radiation patterns over Eastern Mediterranean: Satellite, ground-based, reanalysis data and radiative transfer simulations

    Science.gov (United States)

    Alexandri, G.; Georgoulias, A.; Meleti, C.; Balis, D.

    2013-12-01

    Surface solar radiation (SSR) and its long and short term variations play a critical role in the modification of climate and by extent of the social and financial life of humans. Thus, SSR measurements are of primary importance. SSR is measured for decades from ground-based stations for specific spots around the planet. During the last decades, satellite observations allowed for the assessment of the spatial variability of SSR at a global as well as regional scale. In this study, a detailed spatiotemporal view of the SSR over Eastern Mediterranean is presented at a high spatial resolution. Eastern Mediterranean is affected by various aerosol types (continental, sea, dust and biomass burning particles) and encloses countries with significant socioeconomical changes during the last decades. For the aims of this study, SSR data from satellites (Climate Monitoring Satellite Application Facility - CM SAF) and our ground station in Thessaloniki, a coastal city of ~1 million inhabitants in northern Greece, situated in the heart of Eastern Mediterranean (Eppley Precision pyranometer and Kipp & Zonen CM-11 pyranometer) are used in conjunction with radiative transfer simulations (Santa Barbara DISORT Atmospheric Radiative Transfer - SBDART). The CM SAF dataset used here includes monthly mean SSR observations at a high spatial resolution of 0.03x0.03 degrees for the period 1983-2005. Our ground-based SSR observations span from 1983 until today. SBDART radiative transfer simulations were implemented for a number of spots in the area of study in order to calculate the SSR. High resolution (level-2) aerosol and cloud data from MODIS TERRA and AQUA satellite sensors were used as input, as well as ground-based data from the AERONET. Data from other satellites (Earth Probe TOMS, OMI, etc) and reanalysis projects (ECMWF) were used where needed. The satellite observations, the ground-based measurements and the model estimates are validated against each other. The good agreement

  12. Simultaneous Retrieval of Aerosol and Surface Optical Properties from Combined Airborne- and Ground-Based Direct and Diffuse Radiometric Measurements

    Science.gov (United States)

    Gatebe, C. K.; Dubovik, O.; King, M. D.; Sinyuk, A.

    2010-01-01

    This paper presents a new method for simultaneously retrieving aerosol and surface reflectance properties from combined airborne and ground-based direct and diffuse radiometric measurements. The method is based on the standard Aerosol Robotic Network (AERONET) method for retrieving aerosol size distribution, complex index of refraction, and single scattering albedo, but modified to retrieve aerosol properties in two layers, below and above the aircraft, and parameters on surface optical properties from combined datasets (Cloud Absorption Radiometer (CAR) and AERONET data). A key advantage of this method is the inversion of all available spectral and angular data at the same time, while accounting for the influence of noise in the inversion procedure using statistical optimization. The wide spectral (0.34-2.30 m) and angular range (180 ) of the CAR instrument, combined with observations from an AERONET sunphotometer, provide sufficient measurement constraints for characterizing aerosol and surface properties with minimal assumptions. The robustness of the method was tested on observations made during four different field campaigns: (a) the Southern African Regional Science Initiative 2000 over Mongu, Zambia, (b) the Intercontinental Transport Experiment-Phase B over Mexico City, Mexico (c) Cloud and Land Surface Interaction Campaign over the Atmospheric Radiation Measurement (ARM) Central Facility, Oklahoma, USA, and (d) the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) over Elson Lagoon in Barrow, Alaska, USA. The four areas are dominated by different surface characteristics and aerosol types, and therefore provide good test cases for the new inversion method.

  13. Areal-Averaged Spectral Surface Albedo from Ground-Based Transmission Data Alone: Toward an Operational Retrieval

    Directory of Open Access Journals (Sweden)

    Evgueni Kassianov

    2014-08-01

    Full Text Available We present here a simple retrieval of the areal-averaged spectral surface albedo using only ground-based measurements of atmospheric transmission under fully overcast conditions. Our retrieval is based on a one-line equation. The feasibility of our retrieval for routine determinations of albedo is demonstrated for different landscapes with various degrees of heterogeneity using three sets of measurements: (1 spectral atmospheric transmission from the Multi-Filter Rotating Shadowband Radiometer (MFRSR at five wavelengths (415, 500, 615, 673, and 870 nm; (2 tower-based measurements of local surface albedo at the same wavelengths; and (3 areal-averaged surface albedo at four wavelengths (470, 560, 670 and 860 nm from collocated and coincident Moderate Resolution Imaging Spectroradiometer (MODIS observations. These integrated datasets cover both temporally long (2008–2013 and short (April–May 2010 periods at the Atmospheric Radiation Measurement (ARM Southern Great Plains site and the National Oceanic and Atmospheric Administration (NOAA Table Mountain site, respectively. The calculated root mean square error (RMSE, defined here as the root mean squared difference between the MODIS-derived surface albedo and the retrieved areal-averaged albedo, is quite small (RMSE ≤ 0.015 and comparable with that obtained previously by other investigators for the shortwave broadband albedo. Good agreement between tower-based measurements of daily-averaged surface albedo for completely overcast and non-overcast conditions is also demonstrated.

  14. Survival of adenovirus types 2 and 41 in surface and ground waters measured by a plaque assay.

    Science.gov (United States)

    Rigotto, C; Hanley, K; Rochelle, P A; De Leon, R; Barardi, C R M; Yates, M V

    2011-05-01

    To manage artificial recharge systems, it is necessary to understand the inactivation process of microorganisms within aquifers so that requirements regarding storage times and treatment strategies for ground and surface waters can be developed and modeled to improve water management practices. This study was designed to investigate the survival of representative adenoviruses in surface- and groundwaters using a cell culture plaque assay with human lung carcinoma cells (A549) to enumerate surviving viruses. Adenovirus types 2 (Ad2) and 41 (Ad41) were seeded into 50 mL of three sterilized surface waters and groundwaters, and incubated at 10 and 19 °C for up to 301 days. Concentrations of Ad2 and Ad41 were relatively stable in all waters at 10 °C for at least 160 days and in some instances up to 301 days. At 19 °C, virus concentrations were reduced by 99.99% (4 log) after 301 days in surface water. There was approximately 90% (1 log) reduction of both viruses at 19 °C after 160 days of incubation in groundwater samples. There was no overall difference in survival kinetics in surface waters compared to groundwaters. The relatively high stability and long-term survival of adenoviruses in environmental waters at elevated temperatures should be considered in risk assessment models and drinking water management strategies.

  15. Microscopic Calculation of IBM Parameters by Potential Energy Surface Mapping

    CERN Document Server

    Bentley, I

    2011-01-01

    A coherent state technique is used to generate an Interacting Boson Model (IBM) Hamiltonian energy surface that simulates a mean field energy surface. The method presented here has some significant advantages over previous work. Specifically, that this can be a completely predictive requiring no a priori knowledge of the IBM parameters. The technique allows for the prediction of the low lying energy spectra and electromagnetic transition rates which are of astrophysical interest. Results and comparison with experiment are included for krypton, molybdenum, palladium, cadmium, gadolinium, dysprosium and erbium nuclei.

  16. Evaluating the effects of urbanization and land-use planning using ground-water and surface-water models

    Science.gov (United States)

    Hunt, R.J.; Steuer, J.J.

    2001-01-01

    Why are the effects of urbanization a concern? As the city of Middleton, Wisconsin, and its surroundings continue to develop, the Pheasant Branch watershed (fig.l) is expected to undergo urbanization. For the downstream city of Middleton, urbanization in the watershed can mean increased flood peaks, water volume and pollutant loads. More subtly, it may also reduce water that sustains the ground-water system (called "recharge") and adversely affect downstream ecosystems that depend on ground water such as the Pheasant Branch Springs (hereafter referred to as the Springs). The relation of stormwater runoff and reduced ground-water recharge is complex because the surface-water system is coupled to the underlying ground-water system. In many cases there is movement of water from one system to the other that varies seasonally or daily depending on changing conditions. Therefore, it is difficult to reliably determine the effects of urbanization on stream baseflow and spring flows without rigorous investigation. Moreover, mitigating adverse effects after development has occurred can be expensive and administratively difficult. Overlying these concerns are issues such as stewardship of the resource, the rights of the public, and land owners' rights both of those developing their land and those whose land is affected by this development. With the often- contradictory goals, a scientific basis for assessing effects of urbanization and effectiveness of mitigation measures helps ensure fair and constructive decision-making. The U.S. Geological Survey, in cooperation with the City of Middleton and Wisconsin Department of Natural Resources, completed a study that helps address these issues through modeling of the hydrologic system. This Fact Sheet discusses the results of this work.

  17. Monitoring ground-surface heating during expansion of the Casa Diablo production well field at Mammoth Lakes, California

    Science.gov (United States)

    Bergfeld, D.; Vaughan, R. Greg; Evans, William C.; Olsen, Eric

    2015-01-01

    The Long Valley hydrothermal system supports geothermal power production from 3 binary plants (Casa Diablo) near the town of Mammoth Lakes, California. Development and growth of thermal ground at sites west of Casa Diablo have created concerns over planned expansion of a new well field and the associated increases in geothermal fluid production. To ensure that all areas of ground heating are identified prior to new geothermal development, we obtained high-resolution aerial thermal infrared imagery across the region. The imagery covers the existing and proposed well fields and part of the town of Mammoth Lakes. Imagery results from a predawn flight on Oct. 9, 2014 readily identified the Shady Rest thermal area (SRST), one of two large areas of ground heating west of Casa Diablo, as well as other known thermal areas smaller in size. Maximum surface temperatures at 3 thermal areas were 26–28 °C. Numerous small areas with ground temperatures >16 °C were also identified and slated for field investigations in summer 2015. Some thermal anomalies in the town of Mammoth Lakes clearly reflect human activity.Previously established projects to monitor impacts from geothermal power production include yearly surveys of soil temperatures and diffuse CO2 emissions at SRST, and less regular surveys to collect samples from fumaroles and gas vents across the region. Soil temperatures at 20 cm depth at SRST are well correlated with diffuse CO2 flux, and both parameters show little variation during the 2011–14 field surveys. Maximum temperatures were between 55–67 °C and associated CO2 discharge was around 12–18 tonnes per day. The carbon isotope composition of CO2 is fairly uniform across the area ranging between –3.7 to –4.4 ‰. The gas composition of the Shady Rest fumarole however has varied with time, and H2S concentrations in the gas have been increasing since 2009.

  18. Real-time Accurate Surface Reconstruction Pipeline for Vision Guided Planetary Exploration Using Unmanned Ground and Aerial Vehicles

    Science.gov (United States)

    Almeida, Eduardo DeBrito

    2012-01-01

    This report discusses work completed over the summer at the Jet Propulsion Laboratory (JPL), California Institute of Technology. A system is presented to guide ground or aerial unmanned robots using computer vision. The system performs accurate camera calibration, camera pose refinement and surface extraction from images collected by a camera mounted on the vehicle. The application motivating the research is planetary exploration and the vehicles are typically rovers or unmanned aerial vehicles. The information extracted from imagery is used primarily for navigation, as robot location is the same as the camera location and the surfaces represent the terrain that rovers traverse. The processed information must be very accurate and acquired very fast in order to be useful in practice. The main challenge being addressed by this project is to achieve high estimation accuracy and high computation speed simultaneously, a difficult task due to many technical reasons.

  19. An Approach for Predicting the Shape and Size of a Buried Basic Object on Surface Ground Penetrating Radar System

    Directory of Open Access Journals (Sweden)

    Nana Rachmana Syambas

    2012-01-01

    Full Text Available Surface ground-penetrating radar (GPR is one of the radar technology that is widely used in many applications. It is nondestructive remote sensing method to detect underground buried objects. However, the output target is only hyperbolic representation. This research develops a system to identify a buried object on surface GPR based on decision tree method. GPR data of many basic objects (with circular, triangular, and rectangular cross-section are classified and extracted to generate data training model as a unique template for each type of basic object. The pattern of object under test will be known by comparing its data with the training data using a decision tree method. A simple powerful algorithm to extract feature parameters of object which is based on linear extrapolation is proposed. The result showed that tested buried basic objects can be correctly predicted and the developed system works properly.

  20. Identification and description of potential ground-water quality monitoring wells in Florida

    Science.gov (United States)

    Seaber, P.R.; Thagard, M.E.

    1986-01-01

    The results of a survey of existing wells in Florida that meet the following criteria are presented: (1) well location is known , (2) principal aquifer is known, (3) depth of well is known, (4) well casing depth is known, (5) well water had been analyzed between 1970 and 1982, and (6) well data are stored in the U.S. Geological Survey 's (USGS) computer files. Information for more than 20,000 wells in Florida were stored in the USGS Master Water Data Index of the National Water Data Exchange and in the National Water Data Storage and Retrieval System 's Groundwater Site Inventory computerized files in 1982. Wells in these computer files that had been sampled for groundwater quality before November 1982 in Florida number 13,739; 1,846 of these wells met the above criteria and are the potential (or candidate) groundwater quality monitoring wells included in this report. The distribution by principal aquifer of the 1,846 wells identified as potential groundwater quality monitoring wells is as follows: 1,022 tap the Floridan aquifer system, 114 tap the intermediate aquifers, 232 tap the surficial aquifers, 246 tap the Biscayne aquifer, and 232 tap the sand-and-gravel aquifer. These wells are located in 59 of Florida 's 67 counties. This report presents the station descriptions, which include location , site characteristics, period of record, and the type and frequency of chemical water quality data collected for each well. The 1,846 well locations are plotted on 14 USGS 1:250,000 scale, 1 degree by 2 degree, quadrangle maps. This relatively large number of potential (or candidate) monitoring wells, geographically and geohydrologically dispersed, provides a basis for a future groundwater quality monitoring network and computerized data base for Florida. There is a large variety of water quality determinations available from these wells, both areally and temporally. Future sampling of these wells would permit analyses of time and areal trends for selected water quality

  1. Estimates of global dew collection potential on artificial surfaces

    National Research Council Canada - National Science Library

    Vuollekoski, H; Vogt, M; Sinclair, V. A; Duplissy, J; Järvinen, H; Kyrö, E.-M; Makkonen, R; Petäjä, T; Prisle, N. L; Räisänen, P; Sipilä, M; Ylhäisi, J; Kulmala, M

    2015-01-01

      The global potential for collecting usable water from dew on an artificial collector sheet was investigated by utilizing 34 years of meteorological reanalysis data as input to a dew formation model...

  2. Estimates of global dew collection potential on artificial surfaces

    OpenAIRE

    Vuollekoski, H.; Vogt, M.; Sinclair, V. A.; Duplissy, J; Järvinen, H; Kyrö, E.-M.; R. Makkonen; T. Petäjä; N. L. Prisle; Räisänen, P.; M. Sipilä; J. Ylhäisi; Kulmala, M

    2015-01-01

    The global potential for collecting usable water from dew on an artificial collector sheet was investigated by utilizing 34 years of meteorological reanalysis data as input to a dew formation model. Continental dew formation was found to be frequent and common, but daily yields were mostly below 0.1 mm. Nevertheless, some water-stressed areas such as parts of the coastal regions of northern Africa and the Arabian Peninsula show potential for large-scale dew harvesting, as th...

  3. Estimating Saturated Hydraulic Conductivity from Surface Ground-Penetrating Radar Monitoring of Infiltration

    CERN Document Server

    Léger, Emmanuel; Coquet, Yves

    2013-01-01

    In this study we used Hydrus-1D to simulate water infiltration from a ring infiltrometer. We generated water content profiles at each time step of infiltration, based on a particular value of the saturated hydraulic conductivity while knowing the other van Genuchten parameters. Water content profiles were converted to dielectric permittivity profiles using the Complex Refractive Index Method relation. We then used the GprMax suite of programs to generate radargrams and to follow the wetting front using arrival time of electromagnetic waves recorded by a Ground-Penetrating Radar (GPR). Theoretically, the depth of the inflection point of the water content profile simulated at any infiltration time step is related to the peak of the reflected amplitude recorded in the corresponding trace in the radargram. We used this relationship to invert the saturated hydraulic conductivity for constant and falling head infiltrations. We present our method on synthetic examples and on two experiments carried out on sand. We f...

  4. STUDY OF PHYSICO-CHEMICAL PROPERTIES OF THE SURFACE AND GROUND WATER

    Directory of Open Access Journals (Sweden)

    A. Y. Al-Ghamdi

    2014-01-01

    Full Text Available Of all the natural resources, water is unarguably the most essential and precious. Life began in water and life is nurtured by water. Ninety seven percent of the world’s water is found in oceans. Only 2.5% of the world’s water are non-saline fresh water. Saudi Arabia is a desert country with no permanent rivers or lakes and very little rainfall. Water is scarce and extremely valuable and with the country’s rapid growth, the demand for water is increasing. Seven samples of water are collected, six samples from Wells (1-6 and the last sample from Al-Mallah Valley Dam, Mukhwa (7, Al-Mukhwah, in order to find impurities and pollutants and found some suitable solution. Some physical properties of water are measured such as turbidity, conductivity, pH and also, some pollutants such as iron, manganese, nitrate, nitrite fluoride, phosphate as well as calcium, magnesium, sulfate and chloride as well as detection of some microorganisms. The results shown that, the water of Al-Mallah Valley Dam has a high percentage of turbidity as a result of contamination of water with clay, plant residues and also some dead animals. On the other hand, the samples of ground water have high conductivity and high value of fluoride, nitrite, nitrate contents as well as Mn and Fe. Also the result of microorganisms showed the presence of some the water of Al-Mallah Valley Dam can be treated with a very simple method and become suitable for drinking. Also ground water can be treated with a suitable method to reduce the total hardness and some pollutants. But its content of fluoride is higher than that of gulf specifications so it must be treated before used.

  5. Evaluation of soil liquefaction potential for level ground during earthquakes. A summary report

    Energy Technology Data Exchange (ETDEWEB)

    Seed, H.B.; Arango, I.; Chan, C.K.

    1975-10-01

    The results of a three-year research program conducted to investigate the settlement and liquefaction of sands under multi-directional shaking are evaluated. The investigation indicated that the behavior of a saturated sand under cyclic loading conditions is a function of its geologic and seismic history and grain structure as well as its placement density. It is concluded that the resistance to liquefaction of a sand deposit can best be estimated by laboratory testing on undisturbed samples. It is shown that cyclic triaxial tests used in conjunction with appropriate correction factors to account for multi-directional shaking, simple shear loading conditions, and overconsolidation effects can provide valid data on cyclic loading characteristics. The concepts of ''limited strain potential'' and acceptable value of the factor of safety against initial liquefaction are introduced. Finally, the two basic methods for evaluating liquefaction potential and the effects of liquefaction are reviewed and updated with the information obtained through this research effort.

  6. EOMCC over excited state Hartree-Fock solutions (ESHF-EOMCC: An efficient approach for the entire ground state potential energy curves of higher-order bonds

    Directory of Open Access Journals (Sweden)

    Y. Sajeev

    2015-08-01

    Full Text Available The equation-of-motion coupled cluster (EOMCC method based on the excited state Hartree-Fock (ESHF solutions is shown to be appropriate for computing the entire ground state potential energy curves of strongly correlated higher-order bonds. The new approach is best illustrated for the homolytic dissociation of higher-order bonds in molecules. The required multireference character of the true ground state wavefunction is introduced through the linear excitation operator of the EOMCC method. Even at the singles and doubles level of cluster excitation truncation, the nonparallelity error of the ground state potential energy curve from the ESHF based EOMCC method is small.

  7. Surface-Water, Water-Quality, and Ground-Water Assessment of the Municipio of Mayaguez, Puerto Rico, 1999-2002

    Science.gov (United States)

    Rodríguez-Martínez, Jesús; Santiago-Rivera, Luis; Guzman-Rios, Senen; Gómez-Gómez, Fernando; Oliveras-Feliciano, Mario L.

    2004-01-01

    five hydrogeologic terranes. This integrated database then was used to evaluate the ground-water potential of each hydrogeologic terrane. Lineament-trace analysis was used to help assess the ground-water development potential in the hydrogeologic terranes containing igneous rocks. Analyses suggest that areas with slopes greater than 15 degrees have relatively low ground-water development potential. The presence of fractures, independent of the topographic slope, may locally enhance the water-bearing properties in the hydrogeologic terranes containing igneous rocks. The results of this study indicate that induced streamflow generally is needed to sustain low to moderate ground-water withdrawal rates in the five hydrogeologic terranes. The ground-water flow systems in the hydrogeologic terranes are only able to sustain small withdrawal rates that rarely exceed 50 gallons per minute. Areas with a high density of fractures, as could be the case at the intersection of lineament traces in the upper parts of the Rio Ca?as and Rio Yaguez watersheds, are worthy of exploratory drilling for ground-water development.

  8. Influence of surface conductivity on the apparent zeta potential of calcite

    CERN Document Server

    Li, Shuai; Heberling, Frank; Devau, Nicolas; Jougnot, Damien; Chiaberge, Christophe

    2016-01-01

    Zeta potential is a physicochemical parameter of particular importance in describing the surface electrical properties of charged porous media. However, the zeta potential of calcite is still poorly known because of the difficulty to interpret streaming potential experiments. The Helmholtz-Smoluchowski (HS) equation is widely used to estimate the apparent zeta potential from these experiments. However, this equation neglects the influence of surface conductivity on streaming potential. We present streaming potential and electrical conductivity measurements on a calcite powder in contact with an aqueous NaCl electrolyte. Our streaming potential model corrects the apparent zeta potential of calcite by accounting for the influence of surface conductivity and flow regime. We show that the HS equation seriously underestimates the zeta potential of calcite, particularly when the electrolyte is diluted (ionic strength < 0.01 M) because of calcite surface conductivity. The basic Stern model successfully predicted ...

  9. Characterizing Geothermal Surface Manifestation Based on Multivariate Geostatistics of Ground Measurements Data

    Science.gov (United States)

    Ishaq; Nur Heriawan, Mohamad; Saepuloh, Asep

    2016-09-01

    Mt. Wayang Windu is one of geothermal field located in West Java, Indonesia. The characterization of steam spots at surface manifestation zones based on the soil physical measurements of the area is presented in this study. The multivariate geostatistical methods incorporating the soil physical parameter data were used to characterize the zonation of geothermal surface manifestations. The purpose of this study is to evaluate the performance of spatial estimation method of multivariate geostatistics using Ordinary Cokriging (COK) to characterize the physical properties of geothermal surface manifestations at Mt. Wayang Windu. The COK method was selected because this method is favorable when the secondary variables has more number than the primary variables. There are four soil physical parameters used as the basis of COK method, i.e. Electrical Conductivity, Susceptibility, pH, and Temperature. The parameters were measured directly at and around geothermal surface manifestations including hot springs, fumaroles, and craters. Each location of surface manifestations was measured about 30 points with 30 x 30 m grids. The measurement results were analyzed by descriptive statistics to identify at the nature of data. The correlation among variables was analyzed using linear regression. When the correlation coefficient among variables is higher, the estimation results is expected to have better Linear Coregionalization Model (LCM). LCM was used to analyze the spatial correlation of each variable based on their variogram and cross-variogram model. In oder to evaluate the performance of multivariate geostatistical using COK method, a Root Mean Square Error (RMSE) was performed. Estimation result using COK method is well applicable for characterizing the surface physics parameters of radar images data.

  10. Quality-control results for ground-water and surface-water data, Sacramento River Basin, California, National Water-Quality Assessment, 1996-1998

    Science.gov (United States)

    Munday, Cathy; Domagalski, Joseph L.

    2003-01-01

    Evaluating the extent that bias and variability affect the interpretation of ground- and surface-water data is necessary to meet the objectives of the National Water-Quality Assessment (NAWQA) Program. Quality-control samples used to evaluate the bias and variability include annual equipment blanks, field blanks, field matrix spikes, surrogates, and replicates. This report contains quality-control results for the constituents critical to the ground- and surface-water components of the Sacramento River Basin study unit of the NAWQA Program. A critical constituent is one that was detected frequently (more than 50 percent of the time in blank samples), was detected at amounts exceeding water-quality standards or goals, or was important for the interpretation of water-quality data. Quality-control samples were collected along with ground- and surface-water samples during the high intensity phase (cycle 1) of the Sacramento River Basin NAWQA beginning early in 1996 and ending in 1998. Ground-water field blanks indicated contamination of varying levels of significance when compared with concentrations detected in environmental ground-water samples for ammonia, dissolved organic carbon, aluminum, and copper. Concentrations of aluminum in surface-water field blanks were significant when compared with environmental samples. Field blank samples collected for pesticide and volatile organic compound analyses revealed no contamination in either ground- or surface-water samples that would effect the interpretation of environmental data, with the possible exception of the volatile organic compound trichloromethane (chloroform) in ground water. Replicate samples for ground water and surface water indicate that variability resulting from sample collection, processing, and analysis was generally low. Some of the larger maximum relative percentage differences calculated for replicate samples occurred between samples having lowest absolute concentration differences and(or) values near

  11. Linking air-sea energy exchanges and European anchovy potential spawning ground

    Science.gov (United States)

    Grammauta, R.; Molteni, D.; Basilone, G.; Guisande, C.; Bonanno, A.; Aronica, S.; Giacalone, G.; Fontana, I.; Zora, M.; Patti, B.; Cuttitta, A.; Buscaino, G.; Sorgente, R.; Mazzola, S.

    2008-10-01

    The physical and chemical processes of the sea greatly affect the reproductive biology of fishes, mainly influencing both the numbers of spawned eggs and the survivorship of early stages up to the recruitment period. In the central Mediterranean, the European anchovy constitutes one of the most important fishery resource. Because of its short living nature and of its recruitment variability, associated to high environmental variability, this small pelagic species undergo high interannual fluctuation in the biomass levels. Despite several efforts were addressed to characterize fishes spawning habitat from the oceanographic point of view, very few studies analyze the air-sea exchanges effects. To characterize the spawning habitat of these resources a specific technique (quotient rule analysis) was applied on air-sea heat fluxes, wind stress, sea surface temperature and turbulence data, collected in three oceanographic surveys during the summer period of 2004, 2005 and 2006. The results showed the existence of preferred values in the examined physical variables, associated to anchovy spawning areas. Namely, for heat fluxes the values were around -40 W/m2, for wind stress 0.04-0.11 N/m2, for SST 23°C, and 300 - 500 m3s-3 for wind mixing. Despite the obtained results are preliminary, this is the first relevant analysis on the air-sea exchanges and their relationship with the fish biology of pelagic species.

  12. Atomic size zone interaction potential between two ground-state cold atoms

    CERN Document Server

    Wang, Zhaoying; Wu, Yunhan

    2016-01-01

    The complex-source-point model are already used in the exact solution for the urtrashort pulse and nonparaxial beam. In this letter we have used the complex-source-point model to deduce the interaction potential equation for the separation R between two atoms which is comparable with the size of the atoms. We show the result and the characteristics of the numerical calculation. Since the singular point around R=0 is removed by using the complex-source-point model, so that we can obtain the result force around R=0. With the decreasing of the distance between two atoms, the force switches from the electromagnetic force to the strong force by use our equation.

  13. Ground State Correlations Using exp(S) Method for the Argonne-v18 Potential.

    Science.gov (United States)

    Heisenberg, Jochen; Mihaila, Bogdan

    1997-04-01

    We use the Argonne-v18 potential together with the phenomenological three-nucleon interaction to do the calculation of the mean-field single particle wave functions and the correlation operator S for ^16O. Our correlation operator includes the contributions from up to 4p4h terms. From the three-nucleon interaction we include only those terms that can be written as a density dependent two-body term. We present a breakdown of the contributions to the binding from the two- and the three-body interactions. The one- and the two-body densities for ^16O are presented. Effects of the center-of-mass correction on the charge density and form factor are also discussed.

  14. Ground-Water, Surface-Water, and Water-Chemistry Data, Black Mesa Area, Northeastern Arizona - 2006-07

    Science.gov (United States)

    Truini, Margot; Macy, J.P.

    2008-01-01

    The N aquifer is the major source of water in the 5,400 square-mile Black Mesa area in northeastern Arizona. Availability of water is an important issue in northeastern Arizona because of continued water requirements for industrial and municipal use and the needs of a growing population. Precipitation in the Black Mesa area is typically about 6 to 14 inches per year. The water-monitoring program in the Black Mesa area began in 1971 and is designed to provide information about the long-term effects of ground-water withdrawals from the N aquifer for industrial and municipal uses. This report presents results of data collected for the monitoring program in the Black Mesa area from January 2006 to September 2007. The monitoring program includes measurements of (1) ground-water withdrawals, (2) ground-water levels, (3) spring discharge, (4) surface-water discharge, and (5) ground-water chemistry. Periodic testing of ground-water withdrawal meters is completed every 4 to 5 years. The Navajo Tribal Utility Authority (NTUA) yearly totals for the ground-water metered withdrawal data were unavailable in 2006 due to an up-grade within the NTUA computer network. Because NTUA data is often combined with Bureau of Indian Affairs data for the total withdrawals in a well system, withdrawals will not be published in this year's annual report. From 2006 to 2007, annually measured water levels in the Black Mesa area declined in 3 of 11 wells measured in the unconfined areas of the N aquifer, and the median change was 0.0 feet. Measurements indicated that water levels declined in 8 of 17 wells measured in the confined area of the aquifer. The median change for the confined area of the aquifer was 0.2 feet. From the prestress period (prior to 1965) to 2007, the median water-level change for 30 wells was -11.1 feet. Median water-level changes were 2.9 feet for 11 wells measured in the unconfined areas and -40.2 feet for 19 wells measured in the confined area. Spring flow was measured

  15. Evolution of the potential-energy surface of amorphous silicon

    OpenAIRE

    Kallel, Houssem; Mousseau, Normand; Schiettekatte, François

    2010-01-01

    The link between the energy surface of bulk systems and their dynamical properties is generally difficult to establish. Using the activation-relaxation technique (ART nouveau), we follow the change in the barrier distribution of a model of amorphous silicon as a function of the degree of relaxation. We find that while the barrier-height distribution, calculated from the initial minimum, is a unique function that depends only on the level of distribution, the reverse-barrier height distributio...

  16. Adsorption of lysozyme on base metal surfaces in the presence of an external electric potential.

    Science.gov (United States)

    Ei Ei, Htwe; Nakama, Yuhi; Tanaka, Hiroshi; Imanaka, Hiroyuki; Ishida, Naoyuki; Imamura, Koreyoshi

    2016-11-01

    The impact of external electric potential on the adsorption of a protein to base metal surfaces was examined. Hen egg white lysozyme (LSZ) and six types of base metal plates (stainless steel SUS316L (St), Ti, Ta, Zr, Cr, or Ni) were used as the protein and adsorption surface, respectively. LSZ was allowed to adsorb on the surface under different conditions (surface potential, pH, electrolyte type and concentration, surface material), which was monitored using an ellipsometer. LSZ adsorption was minimized in the potential range above a certain threshold and, in the surface potential range below the threshold, decreasing the surface potential increased the amount of protein adsorbed. The threshold potential for LSZ adsorption was shifted toward a positive value with increasing pH and was lower for Ta and Zr than for the others. A divalent anion salt (K2SO4) as an electrolyte exhibited the adsorption of LSZ in the positive potential range while a monovalent salt (KCl) did not. A comprehensive consideration of the obtained results suggests that two modes of interactions, namely the electric force by an external electric field and electrostatic interactions with ionized surface hydroxyl groups, act on the LSZ molecules and determine the extent of suppression of LSZ adsorption. All these findings appear to support the view that a base metal surface can be controlled for the affinity to a protein by manipulating the surface electric potential as has been reported on some electrode materials.

  17. Expanding surfaces: The viewer immersed in multiple modes of representation Following the drawing on the ground

    DEFF Research Database (Denmark)

    Carbone, Claudia

    2015-01-01

    The experience of the exhibition On the Surface – a retrospective of the work of Metis, the Edinburgh-based atelier of Mark Dorrian and Adrian Hawker, presented in the exhibition space of The Aarhus School of Architecture – is choreographed as a walk over superimposed fragments of architectural...

  18. Hydrology, Water Quality, and Surface- and Ground-Water Interactions in the Upper Hillsborough River Watershed, West-Central Florida

    Science.gov (United States)

    Trommer, J.T.; Sacks, L.A.; Kuniansky, E.L.

    2007-01-01

    A study of the Hillsborough River watershed was conducted between October 1999 through September 2003 to characterize the hydrology, water quality, and interaction between the surface and ground water in the highly karstic uppermost part of the watershed. Information such as locations of ground-water recharge and discharge, depth of the flow system interacting with the stream, and water quality in the watershed can aid in prudent water-management decisions. The upper Hillsborough River watershed covers a 220-square-mile area upstream from Hillsborough River State Park where the watershed is relatively undeveloped. The watershed contains a second order magnitude spring, many karst features, poorly drained swamps, marshes, upland flatwoods, and ridge areas. The upper Hillsborough River watershed is subdivided into two major subbasins, namely, the upper Hillsborough River subbasin, and the Blackwater Creek subbasin. The Blackwater Creek subbasin includes the Itchepackesassa Creek subbasin, which in turn includes the East Canal subbasin. The upper Hillsborough River watershed is underlain by thick sequences of carbonate rock that are covered by thin surficial deposits of unconsolidated sand and sandy clay. The clay layer is breached in many places because of the karst nature of the underlying limestone, and the highly variable degree of confinement between the Upper Floridan and surficial aquifers throughout the watershed. Potentiometric-surface maps indicate good hydraulic connection between the Upper Floridan aquifer and the Hillsborough River, and a poorer connection with Blackwater and Itchepackesassa Creeks. Similar water level elevations and fluctuations in the Upper Floridan and surficial aquifers at paired wells also indicate good hydraulic connection. Calcium was the dominant ion in ground water from all wells sampled in the watershed. Nitrate concentrations were near or below the detection limit in all except two wells that may have been affected by

  19. Imaging a multidimensional multichannel potential energy surface: Photodetachment of H-(NH3) and NH4-

    Science.gov (United States)

    Hu, Qichi; Song, Hongwei; Johnson, Christopher J.; Li, Jun; Guo, Hua; Continetti, Robert E.

    2016-06-01

    Probes of the Born-Oppenheimer potential energy surfaces governing polyatomic molecules often rely on spectroscopy for the bound regions or collision experiments in the continuum. A combined spectroscopic and half-collision approach to image nuclear dynamics in a multidimensional and multichannel system is reported here. The Rydberg radical NH4 and the double Rydberg anion NH4- represent a polyatomic system for benchmarking electronic structure and nine-dimensional quantum dynamics calculations. Photodetachment of the H-(NH3) ion-dipole complex and the NH4- DRA probes different regions on the neutral NH4 PES. Photoelectron energy and angular distributions at photon energies of 1.17, 1.60, and 2.33 eV compare well with quantum dynamics. Photoelectron-photofragment coincidence experiments indicate dissociation of the nascent NH4 Rydberg radical occurs to H + NH3 with a peak kinetic energy of 0.13 eV, showing the ground state of NH4 to be unstable, decaying by tunneling-induced dissociation on a time scale beyond the present scope of multidimensional quantum dynamics.

  20. Efficient generation of Heisenberg Hamiltonian matrices for VB calculations of potential energy surfaces

    Science.gov (United States)

    Tokmachev, A. M.; Robb, M. A.

    The spin-Hamiltonian valence bond theory relies upon covalent configurations formed by singly occupied orbitals differing by their spin counterparts. This theory has been proven to be successful in studying potential energy surfaces of the ground and lowest excited states in organic molecules when used as a part of the hybrid molecular mechanics - valence bond method. The method allows one to consider systems with large active spaces formed by n electrons in n orbitals and relies upon a specially proposed graphical unitary group approach. At the same time, the restriction of the equality of the numbers of electrons and orbitals in the active space is too severe: it excludes from the consideration a lot of interesting applications. We can mention here carbocations and systems with heteroatoms. Moreover, the structure of the method makes it difficult to study charge-transfer excited states because they are formed by ionic configurations. In the present work we tackle these problems by significant extension of the spin-Hamiltonian approach. We consider (i) more general active space formed by n ± m electrons in n orbitals and (ii) states with the charge transfer. The main problem addressed is the generation of Hamiltonian matrices for these general cases. We propose a scheme combining operators of electron exchange and hopping, generating all nonzero matrix elements step-by-step. This scheme provides a very efficient way to generate the Hamiltonians, thus extending the applicability of spin-Hamiltonian valence bond theory.

  1. Modeling of ground temperatures in South Shetlands (Antarctic Peninsula): Forcing a land surface model with the reanalysis ERA-Interim

    Science.gov (United States)

    João Rocha, Maria; Dutra, Emanuel; Vieira, Gonçalo; Miranda, Pedro; Ramos, Miguel

    2010-05-01

    This study focus on Livingston Island (South Shetlands Antarctic Peninsula), one of the Earth's regions where warming has been more significant in the last 50 years. Our work is integrated in a project focusing on studying the influence of climate change on permafrost temperatures, which includes systematic and long-term terrain monitoring and also modeling using land surface models. A contribution will be the evaluation of the possibilities for using land surface modeling approaches to areas of the Antarctic Peninsula with lack of data on observational meteorological forcing data, as well as on permafrost temperatures. The climate variability of the Antarctic Peninsula region was studied using the new reanalysis product from European Centre for Medium-Range Weather Forecasts (ECMWF) Era-Interim and observational data from boreholes run by our group. Monthly and annual cycles of near surface climate variables are compared. The modeling approach includes the HTESSEL (Hydrology Tiled ECMWF Scheme for Surface Exchanges over Land) forced with ERA-Interim for modeling ground temperatures in the study region. The simulation results of run of HTESSEL are compared against soil temperature observations. The results show a favorable match between simulated and observed soil temperatures. The use of different forcing parameters is compared and the model vs. observation results from different results is analyzed. The main variable needing further improvement in the modeling is snow cover. The developed methodology provides a good tool for the analysis of the influence of climate variability on permafrost of the Maritime Antarctic.

  2. Ground and surface temperature variability for remote sensing of soil moisture in a heterogeneous landscape

    Science.gov (United States)

    Giraldo, M.A.; Bosch, D.; Madden, M.; Usery, L.; Finn, M.

    2009-01-01

    At the Little River Watershed (LRW) heterogeneous landscape near Tifton Georgia US an in situ network of stations operated by the US Department of Agriculture-Agriculture Research Service-Southeast Watershed Research Lab (USDA-ARS-SEWRL) was established in 2003 for the long term study of climatic and soil biophysical processes. To develop an accurate interpolation of the in situ readings that can be used to produce distributed representations of soil moisture (SM) and energy balances at the landscape scale for remote sensing studies, we studied (1) the temporal and spatial variations of ground temperature (GT) and infra red temperature (IRT) within 30 by 30 m plots around selected network stations; (2) the relationship between the readings from the eight 30 by 30 m plots and the point reading of the network stations for the variables SM, GT and IRT; and (3) the spatial and temporal variation of GT and IRT within agriculture landuses: grass, orchard, peanuts, cotton and bare soil in the surrounding landscape. The results showed high correlations between the station readings and the adjacent 30 by 30 m plot average value for SM; high seasonal independent variation in the GT and IRT behavior among the eight 30 by 30 m plots; and site specific, in-field homogeneity in each 30 by 30 m plot. We found statistical differences in the GT and IRT between the different landuses as well as high correlations between GT and IRT regardless of the landuse. Greater standard deviations for IRT than for GT (in the range of 2-4) were found within the 30 by 30 m, suggesting that when a single point reading for this variable is selected for the validation of either remote sensing data or water-energy models, errors may occur. The results confirmed that in this landscape homogeneous 30 by 30 m plots can be used as landscape spatial units for soil moisture and ground temperature studies. Under this landscape conditions small plots can account for local expressions of environmental

  3. The ground state of long-range Schrödinger equations and static qoverline{q} potential

    Science.gov (United States)

    Beccaria, Matteo; Metafune, Giorgio; Pallara, Diego

    2016-05-01

    Motivated by the recent results in arXiv:1601.05679 URL"/> about the quark-antiquark potential in {N} = 4 SYM, we reconsider the problem of computing the asymptotic weak-coupling expansion of the ground state energy of a certain class of 1d Schrödinger operators -d^2/d{x^2}+λ V(x) with long-range potential V ( x). In particular, we consider even potentials obeying ∫ ℝ dx V( x) < 0 with large x asymptotics V ˜ - a/x 2 - b/x 3 + · · · . The associated Schrödinger operator is known to admit a bound state for λ → 0+, but the binding energy is rigorously non-analytic at λ = 0. Its asymptotic expansion starts at order {O} (λ), but contains higher corrections λ n log m λ with all 0 ≤ m ≤ n - 1 and standard Rayleigh-Schrödinger perturbation theory fails order by order in λ. We discuss various analytical tools to tame this problem and provide the general expansion of the binding energy at {O} (λ3) in terms of quadratures. The method is tested on a soluble potential that is fully under control, and on various non-soluble cases as well. A supersymmetric case, arising in the study of the quark-antiquark potential in {N} = 6 ABJ(M) theory, is also exploited to provide a further non-trivial consistency check. Our analytical results confirm at third order a remarkable exponentiation of the leading infrared logarithms, first noticed in {N} = 4 SYM where it may be proved by Renormalization Group arguments. We prove this interesting feature at all orders at the level of the Schrödinger equation for general potentials in the considered class.

  4. The ground state of long-range Schrödinger equations and static qq̄ potential

    Energy Technology Data Exchange (ETDEWEB)

    Beccaria, Matteo [Dipartimento di Matematica e Fisica Ennio De Giorgi,Università del Salento, Via Arnesano, 73100 Lecce (Italy); INFN, Via Arnesano, 73100 Lecce (Italy); Metafune, Giorgio [Dipartimento di Matematica e Fisica Ennio De Giorgi,Università del Salento, Via Arnesano, 73100 Lecce (Italy); Pallara, Diego [Dipartimento di Matematica e Fisica Ennio De Giorgi,Università del Salento, Via Arnesano, 73100 Lecce (Italy); INFN, Via Arnesano, 73100 Lecce (Italy)

    2016-05-06

    Motivated by the recent results in http://arxiv.org/abs/1601.05679 about the quark-antiquark potential in N=4 SYM, we reconsider the problem of computing the asymptotic weak-coupling expansion of the ground state energy of a certain class of 1d Schrödinger operators −((d{sup 2})/(dx{sup 2}))+λ V(x) with long-range potential V(x). In particular, we consider even potentials obeying ∫{sub ℝ}dx V(x)<0 with large x asymptotics V∼−a/x{sup 2}−b/x{sup 3}+⋯. The associated Schrödinger operator is known to admit a bound state for λ→0{sup +}, but the binding energy is rigorously non-analytic at λ=0. Its asymptotic expansion starts at order O(λ), but contains higher corrections λ{sup n} log{sup m} λ with all 0≤m≤n−1 and standard Rayleigh-Schrödinger perturbation theory fails order by order in λ. We discuss various analytical tools to tame this problem and provide the general expansion of the binding energy at O(λ{sup 3}) in terms of quadratures. The method is tested on a soluble potential that is fully under control, and on various non-soluble cases as well. A supersymmetric case, arising in the study of the quark-antiquark potential in N=6 ABJ(M) theory, is also exploited to provide a further non-trivial consistency check. Our analytical results confirm at third order a remarkable exponentiation of the leading infrared logarithms, first noticed in N=4 SYM where it may be proved by Renormalization Group arguments. We prove this interesting feature at all orders at the level of the Schrödinger equation for general potentials in the considered class.

  5. Comparison of the surface energy budget between regions of seasonally frozen ground and permafrost on the Tibetan Plateau

    Science.gov (United States)

    Gu, Lianglei; Yao, Jimin; Hu, Zeyong; Zhao, Lin

    2015-02-01

    Surface energy budgets were calculated using turbulent flux observation data and meteorological gradient data collected in 2008 from two sites: BJ, located in a seasonally frozen ground region, and Tanggula, located in a permafrost region. In 2008, the energy closure ratios for the BJ and Tanggula sites were 0.74 and 0.73, respectively, using 30-min instantaneous energy flux data but 0.87 and 0.99, respectively, using daily average energy flux data. Therefore, the energy closure status is related to the time scale that is used for the study. The variation in the surface energy budget at the two sites was similar: The sensible heat flux (Hs) was relatively high in spring and reduced in summer but gradually increased in autumn. The latent heat flux (LE) was higher in summer and autumn but lower in winter and spring. Comparably, the starting time for the significant increase in LE occurred earlier at the Tanggula site than that at the BJ site, because the freezing and thawing progress of the active layer of permafrost at Tanggula site significantly affected the Hs and LE distributions, but the freezing and thawing processes of the soil at BJ site did not significantly affect the Hs and LE distributions. The monsoon significantly affected the variation in Hs and LE at both the BJ and Tanggula sites. Regarding the diurnal variation of the energy budget at the two sites, the daily maximum of net radiation (Rn) occurred at approximately 14:00 Beijing Time, and the daily maximum of ground heat flux (G0) was earlier than those of Hs and LE. The albedo and Bowen ratio for the two sites were both low in summer but high in winter. The albedo increased significantly but the Bowen ratio became lower or even negative when the surface was covered with deep snow.

  6. Effect of Surface Geology on Ground Motions: The Case of Station TAP056 - Chutzuhu Site

    Directory of Open Access Journals (Sweden)

    Kuo-Liang Wen

    2008-01-01

    Full Text Available In the Tatun mountain area of northern Taiwan are two strong motion stations approximately 2.5 km apart, TAP056 and TAP066 of the TSMIP network. The accelerometer at station TAP056 is often triggered by earthquakes, but that at TAP066 station is not. Comparisons of vertical and horizontal peak ground accelerations reveal PGA in the vertical, east-west, and north-south components at TAP056 station to be 3.89, 7.57, and 5.45 times those at station TAP066, respectively. The PGA ratio does not seem to be related to earthquake source or path. Fourier spectra of earthquake records at station TAP056 always have approximately the same dominant frequency; however, those at station TAP066 are different due to different sources and paths of different events. This shows that spectra at TAP056 station are mainly controlled by local site effects. The spectral ratios of TAP056/TAP066 show the S-wave is amplified at around 8 ~ 10 Hz. The horizontal/vertical spectral ratios of station TAP056 also show a dominant frequency at about 6 and 8 ~ 10 Hz. After dense microtremor surveying and the addition of one accelerometer just 20 meters away from the original observation station, we can confirm that the top soft soil layer upon which the observation station is constructed generates the local site response at station TAP056.

  7. Surface chemistry dependent immunostimulative potential of porous silicon nanoplatforms.

    Science.gov (United States)

    Shahbazi, Mohammad-Ali; Fernández, Tahia D; Mäkilä, Ermei M; Le Guével, Xavier; Mayorga, Cristobalina; Kaasalainen, Martti H; Salonen, Jarno J; Hirvonen, Jouni T; Santos, Hélder A

    2014-11-01

    Nanoparticles (NPs) have been suggested for immunotherapy applications in order to optimize the delivery of immuno-stimulative or -suppressive molecules. However, low attention towards the impact of the NPs' physicochemical properties has presented a major hurdle for developing efficient immunotherapeutic agents. Here, the effects of porous silicon (PSi) NPs with different surface chemistries were evaluated on human monocyte-derived dendritic cells (MDDCs) and lymphocytes in order to highlight the importance of the NPs selection in immuno-stimulative or -suppressive treatment. Although all the PSi NPs showed high biocompatibility, only thermally oxidized PSi (TOPSi) and thermally hydrocarbonized PSi (THCPSi) NPs were able to induce very high rate of immunoactivation by enhancing the expression of surface co-stimulatory markers of the MDDCs (CD80, CD83, CD86, and HLA-DR), inducing T-cell proliferation, and also the secretion of interleukins (IL-1β, IL-4, IL-6, IL-10, IL-12, IFN-γ, and TNF-α). These results indicated a balanced increase in the secretion of Th1, Th2, and Treg cytokines. Moreover, undecylenic acid functionalized THCPSi, as well as poly(methyl vinyl ether-alt-maleic acid) conjugated to (3-aminopropyl)triethoxysilane functionalized thermally carbonized PSi and polyethyleneimine conjugated undecylenic acid functionalized THCPSi NPs showed moderate immunoactivation due to the mild increase in the above-mentioned markers. By contrast, thermally carbonized PSi (TCPSi) and (3-aminopropyl)triethoxysilane functionalized TCPSi NPs did not induce any immunological responses, suggesting that their application could be in the delivery of immunosuppressive molecules. Overall, our findings suggest all the NPs containing more nitrogen or oxygen on the outermost backbone layer have lower immunostimulatory effect than NPs with higher C-H structures on the surface.

  8. Surface thermophysical properties on the potentially hazardous asteroid (99942) Apophis

    Science.gov (United States)

    Yu, Liang-Liang; Ji, Jianghui; Ip, Wing-Huen

    2017-07-01

    We investigate the surface thermophysical properties (thermal emissivity, thermal inertia, roughness fraction and geometric albedo) of asteroid (99942) Apophis, using the currently available mid-infrared observations from CanariCam on Gran Telescopio CANARIAS and far-infrared data from PACS on Herschel, based on the Advanced Thermophysical Model. We show that the thermal emissivity of Apophis should be wavelength dependent from 8.70 μm to 160 μm, and the maximum emissivity may appear around 20 μm, similar to that of Vesta. Moreover, we further derive the thermal inertia, roughness fraction, geometric albedo and effective diameter of Apophis within a possible 1σ scale of Γ ={100}-52+100{{{Jm}}}{{-}2} {{{s}}}{{-}0.{{5}}} {{{K}}}{{-}1}, {f}{{r}}=0.78˜ 1.0, {p}{{v}}={0.286}-0.026+0.030 and {D}{{eff}}={378}-25+19{{m}}, and 3σ scale of Γ ={100}-100+240 {{{Jm}}}{{-}2} {{{s}}}{{-}0.{{5}}} {{{K}}}{{-}1}, {f}{{r}}=0.2˜ 1.0, {p}{{v}}={0.286}-0.029+0.039 and {D}{{eff}}={378}-29+27{{m}}. The derived low thermal inertia but high roughness fraction may imply that Apophis could have regolith on its surface, where stronger space weathering but weaker regolith migration has happened in comparison with asteroid Itokawa. Our results show that small-size asteroids could also have fine regolith on the surface, and further infer that Apophis may have been delivered from the Main Belt by the Yarkovsky effect.

  9. Mapping of the cumulative β-ray dose on the ground surface surrounding the Fukushima area

    Science.gov (United States)

    Endo, Satoru; Kajimoto, Tsuyoshi; Tanaka, Kenichi; Nguyen, Thanh T.; Hayashi, Gohei; Imanaka, Tetsuji

    2015-01-01

    A large amount of the fission products released by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on 11 March 2011 was deposited in a wide area from Tohoku to northern Kanto. A map of the estimated cumulative β-ray dose (70 μm dose equivalent) on the soil surface for one year after the FDNPP accident has been prepared using previously reported calculation methods and the 2-km mesh survey data by MEXT. From this map of estimated dose, areas with a high cumulative β-ray dose on the soil surface for one year after the FDNPP accident were found to be located in the Akogi-Teshichiro to Akogi-Kunugidaira region in Namie Town, and in the southern Futaba Town to the northern Tomioka Town region. The highest estimated cumulative β-ray dose was 710 mSv for one year at Akogi-Teshichiro, Namie Town. PMID:26519736

  10. Transport signatures of surface potentials on three-dimensional topological insulators

    Science.gov (United States)

    Roy, Sthitadhi; Das, Sourin

    2016-02-01

    The spin-momentum-locked nature of the robust surface states of three-dimensional topological insulators (3D TIs) makes them promising candidates for spintronics applications. Surface potentials which respect time-reversal symmetry can exist at the surface between a 3D TI and the trivial vacuum. These potentials can distort the spin texture of the surface states while retaining their gapless nature. In this work, the effect of all such surface potentials on the spin textures is studied. Since a tunnel magnetoresistance signal carries the information of the spin texture, it is proposed that spin-polarized tunneling of electrons to a 3D TI surface can be used to uniquely identify the surface potentials and quantitatively characterize them.

  11. The potential of advanced ground-based gravitational wave detectors to detect generic deviations from general relativity

    Science.gov (United States)

    Narikawa, Tatsuya; Tagoshi, Hideyuki

    2016-09-01

    We discuss the potential of advanced ground-based gravitational wave detectors such as LIGO, Virgo, and KAGRA to detect generic deviations of gravitational waveforms from the predictions of general relativity. We use the parameterized post-Einsteinian formalism to characterize the deviations, and assess what magnitude of deviations are detectable by using an approximate decision scheme based on Bayesian statistics. We find that there exist detectable regions of the parameterized post-Einsteinian parameters for different binary masses from the observation of a single gravitational wave event. The regions are not excluded by currently existing binary pulsar observations for the parameterized post-Einsteinian parameters at higher post-Newtonian order. We also find that neglect of orbital eccentricity or tidal deformation effects do not cause a significant bias on the detectable region of generic deviations from general relativity.

  12. Type of Ground Surface during Plyometric Training Affects the Severity of Exercise-Induced Muscle Damage

    Directory of Open Access Journals (Sweden)

    Hamid Arazi

    2016-03-01

    Full Text Available The purpose of this study was to compare the changes in the symptoms of exercise-induced muscle damage from a bout of plyometric exercise (PE; 10 × 10 vertical jumps performed in aquatic, sand and firm conditions. Twenty-four healthy college-aged men were randomly assigned to one of three groups: Aquatic (AG, n = 8, Sand (SG, n = 8 and Firm (FG, n = 8. The AG performed PE in an aquatic setting with a depth of ~130 cm. The SG performed PE on a dry sand surface at a depth of 20 cm, and the FG performed PE on a 10-cm-thick wooden surface. Plasma creatine kinase (CK activity, delayed onset muscle soreness (DOMS, knee range of motion (KROM, maximal isometric voluntary contraction (MIVC of the knee extensors, vertical jump (VJ and 10-m sprint were measured before and 24, 48 and 72 h after the PE. Compared to baseline values, FG showed significantly (p < 0.05 greater changes in CK, DOMS, and VJ at 24 until 48 h. The MIVC decreased significantly for the SG and FG at 24 until 48 h post-exercise in comparison to the pre-exercise values. There were no significant (p > 0.05 time or group by time interactions in KROM. In the 10-m sprint, all the treatment groups showed significant (p < 0.05 changes compared to pre-exercise values at 24 h, and there were no significant (p > 0.05 differences between groups. The results indicate that PE in an aquatic setting and on a sand surface induces less muscle damage than on a firm surface. Therefore, training in aquatic conditions and on sand may be beneficial for the improvement of performance, with a concurrently lower risk of muscle damage and soreness.

  13. Commons problems, common ground: Earth-surface dynamics and the social-physical interdisciplinary frontier

    Science.gov (United States)

    Lazarus, E.

    2015-12-01

    In the archetypal "tragedy of the commons" narrative, local farmers pasture their cows on the town common. Soon the common becomes crowded with cows, who graze it bare, and the arrangement of open access to a shared resource ultimately fails. The "tragedy" involves social and physical processes, but the denouement depends on who is telling the story. An economist might argue that the system collapses because each farmer always has a rational incentive to graze one more cow. An ecologist might remark that the rate of grass growth is an inherent control on the common's carrying capacity. And a geomorphologist might point out that processes of soil degradation almost always outstrip processes of soil production. Interdisciplinary research into human-environmental systems still tends to favor disciplinary vantages. In the context of Anthropocene grand challenges - including fundamental insight into dynamics of landscape resilience, and what the dominance of human activities means for processes of change and evolution on the Earth's surface - two disciplines in particular have more to talk about than they might think. Here, I use three examples - (1) beach nourishment, (2) upstream/downstream fluvial asymmetry, and (3) current and historical "land grabbing" - to illustrate a range of interconnections between physical Earth-surface science and common-pool resource economics. In many systems, decision-making and social complexity exert stronger controls on landscape expression than do physical geomorphological processes. Conversely, human-environmental research keeps encountering multi-scale, emergent problems of resource use made 'common-pool' by water, nutrient and sediment transport dynamics. Just as Earth-surface research can benefit from decades of work on common-pool resource systems, quantitative Earth-surface science can make essential contributions to efforts addressing complex problems in environmental sustainability.

  14. Influence of surface conductivity on the apparent zeta potential of calcite.

    Science.gov (United States)

    Li, Shuai; Leroy, Philippe; Heberling, Frank; Devau, Nicolas; Jougnot, Damien; Chiaberge, Christophe

    2016-04-15

    Zeta potential is a physicochemical parameter of particular importance in describing the surface electrical properties of charged porous media. However, the zeta potential of calcite is still poorly known because of the difficulty to interpret streaming potential experiments. The Helmholtz-Smoluchowski (HS) equation is widely used to estimate the apparent zeta potential from these experiments. However, this equation neglects the influence of surface conductivity on streaming potential. We present streaming potential and electrical conductivity measurements on a calcite powder in contact with an aqueous NaCl electrolyte. Our streaming potential model corrects the apparent zeta potential of calcite by accounting for the influence of surface conductivity and flow regime. We show that the HS equation seriously underestimates the zeta potential of calcite, particularly when the electrolyte is diluted (ionic strength ⩽ 0.01 M) because of calcite surface conductivity. The basic Stern model successfully predicted the corrected zeta potential by assuming that the zeta potential is located at the outer Helmholtz plane, i.e. without considering a stagnant diffuse layer at the calcite-water interface. The surface conductivity of calcite crystals was inferred from electrical conductivity measurements and computed using our basic Stern model. Surface conductivity was also successfully predicted by our surface complexation model.

  15. Immobilization and surface functionalization of gold nanoparticles monitored via streaming current/potential measurements.

    Science.gov (United States)

    Greben, Kyrylo; Li, Pinggui; Mayer, Dirk; Offenhäusser, Andreas; Wördenweber, Roger

    2015-05-14

    A streaming current/potential method is optimized and used for the analysis of the variation of the surface potential upon chemical modifications of a complex interface consisting of different organic molecules and gold nanoparticles (AuNPs). The surfaces of Si/SiO2 substrates modified with 3-aminopropyltriethoxysilane (APTES), AuNPs, and 11-amino-1-undecanethiol (aminothiols) are analyzed via pH and time dependent ζ potential measurements that reveal the stability and modification of the surface and identify crucial parameters for each individual preparation step. For instance, surface activation and especially molecular adsorbate layers tend not to be stable in time, whereas the substrate and the AuNPs provide a stable surface potential as long as impurities are avoided. It is shown that the streaming potential/current technique represents an ideal tool to analyze and monitor the complex surfaces and their modification.

  16. Intersections of potential energy surfaces of short-lived states: the complex analogue of conical intersections.

    Science.gov (United States)

    Feuerbacher, Sven; Sommerfeld, Thomas; Cederbaum, Lorenz S

    2004-02-15

    Whereas conical intersections between potential energy surfaces of bound states are well known, the interaction of short-lived states has been investigated only rarely. Here, we present several systematically constructed model Hamiltonians to study the topology of intersecting complex potential energy surfaces describing short-lived states: We find the general phenomenon of doubly intersecting complex energy surfaces, i.e., there are two points instead of one as in the case of bound states where the potential energy surfaces coalesce. In addition, seams of intersections of the respective real and imaginary parts of the potential energy surfaces emanate from these two points. Using the Sigma* and Pi* resonance states of the chloroethene anion as a practical example, we demonstrate that our complete linear model Hamiltonian is able to reproduce all phenomena found in explicitly calculated ab initio complex potential energy surfaces.

  17. Seismic interferometry of railroad induced ground motions: body and surface wave imaging

    Science.gov (United States)

    Quiros, Diego A.; Brown, Larry D.; Kim, Doyeon

    2016-04-01

    Seismic interferometry applied to 120 hr of railroad traffic recorded by an array of vertical component seismographs along a railway within the Rio Grande rift has recovered surface and body waves characteristic of the geology beneath the railway. Linear and hyperbolic arrivals are retrieved that agree with surface (Rayleigh), direct and reflected P waves observed by nearby conventional seismic surveys. Train-generated Rayleigh waves span a range of frequencies significantly higher than those recovered from typical ambient noise interferometry studies. Direct P-wave arrivals have apparent velocities appropriate for the shallow geology of the survey area. Significant reflected P-wave energy is also present at relatively large offsets. A common midpoint stack produces a reflection image consistent with nearby conventional reflection data. We suggest that for sources at the free surface (e.g. trains) increasing the aperture of the array to record wide angle reflections, in addition to longer recording intervals, might allow the recovery of deeper geological structure from railroad traffic. Frequency-wavenumber analyses of these recordings indicate that the train source is symmetrical (i.e. approaching and receding) and that deeper refracted energy is present although not evident in the time-offset domain. These results confirm that train-generated vibrations represent a practical source of high-resolution subsurface information, with particular relevance to geotechnical and environmental applications.

  18. Hydrogeology, water quality, and potential for contamination of the Upper Floridan aquifer in the Silver Springs ground-water basin, central Marion County, Florida

    Science.gov (United States)

    Phelps, G.G.

    1994-01-01

    The Upper Floridan aquifer, composed of a thick sequence of very porous limestone and dolomite, is the principal source of water supply in the Silver Springs ground-water basin of central Marion County, Florida. The karstic nature of the local geology makes the aquifer susceptible to contaminants from the land surface. Contaminants can enter the aquifer by seepage through surficial deposits and through sinkholes and drainage wells. Potential contaminants include agricultural chemicals, landfill leachates and petroleum products from leaking storage tanks and accidental spills. More than 560 sites of potential contamination sources were identified in the basin in 1990. Detailed investigation of four sites were used to define hydrologic conditions at representative sites. Ground-water flow velocities determined from dye trace studies ranged from about 1 foot per hour under natural flow conditions to about 10 feet per hour under pumping conditions, which is considerably higher than velocities estimated using Darcy's equation for steady-state flow in a porous medium. Water entering the aquifer through drainage wells contained bacteria, elevated concentrations of nutrients, manganese and zinc, and in places, low concentrations of organic compounds. On the basis of results from the sampling of 34 wells in 1989 and 1990, and from the sampling of water entering the Upper Floridan aquifer through drainage wells, there has been no widespread degradation of water quality in the study area. In an area of karst, particularly one in which fracture flow is significant, evaluating the effects from contaminants is difficult and special care is required when interpolating hydrogeologic data from regional studies to a specific. (USGS)

  19. Estimates of global dew collection potential on artificial surfaces

    Science.gov (United States)

    Vuollekoski, H.; Vogt, M.; Sinclair, V. A.; Duplissy, J.; Järvinen, H.; Kyrö, E.-M.; Makkonen, R.; Petäjä, T.; Prisle, N. L.; Räisänen, P.; Sipilä, M.; Ylhäisi, J.; Kulmala, M.

    2015-01-01

    The global potential for collecting usable water from dew on an artificial collector sheet was investigated by utilizing 34 years of meteorological reanalysis data as input to a dew formation model. Continental dew formation was found to be frequent and common, but daily yields were mostly below 0.1 mm. Nevertheless, some water-stressed areas such as parts of the coastal regions of northern Africa and the Arabian Peninsula show potential for large-scale dew harvesting, as the yearly yield may reach up to 100 L m-2 for a commonly used polyethylene foil. Statistically significant trends were found in the data, indicating overall changes in dew yields of between ±10% over the investigated time period.

  20. Monitoring of the ground surface temperature and the active layer in NorthEastern Canadian permafrost areas using remote sensing data assimilated in a climate land surface scheme.

    Science.gov (United States)

    Marchand, N.; Royer, A.; Krinner, G.; Roy, A.

    2014-12-01

    Projected future warming is particularly strong in the Northern high latitudes where increases of temperatures are up to 2 to 6 °C. Permafrost is present on 25 % of the northern hemisphere lands and contain high quantities of « frozen » carbon, estimated at 1400 Gt (40 % of the global terrestrial carbon). The aim of this study is to improve our understanding of the climate evolution in arctic areas, and more specifically of land areas covered by snow. The objective is to describe the ground temperature year round including under snow cover, and to analyse the active layer thickness evolution in relation to the climate variability. We use satellite data (fusion of MODIS land surface temperature « LST » and microwave AMSR-E brightness temperature « Tb ») assimilated in the Canadian Land Surface Scheme (CLASS) of the Canadian climate model coupled with a simple radiative transfer model (HUT). This approach benefits from the advantages of each of the data type in order to complete two objectives : 1- build a solid methodology for retrieving the ground temperature, with and without snow cover, in taïga and tundra areas ; 2 - from those retrieved ground temperatures, derive the summer melt duration and the active layer depth. We describe the coupling of the models and the methodology that adjusts the meteorological input parameters of the CLASS model (mainly air temperature and precipitations derived from the NARR database) in order to minimise the simulated LST and Tb ouputs in comparison with satellite measurements. Using ground-based meteorological data as validation references in NorthEastern Canadian tundra, the results show that the proposed approach improves the soil temperatures estimates when using the MODIS LST and Tb at 10 and 19 GHz to constrain the model in comparison with the model outputs without satellite data. Error analysis is discussed for the summer period (2.5 - 4 K) and for the snow covered winter period (2 - 3.5 K). Further steps are

  1. SPECTROSCOPIC PROBING OF POTENTIAL SURFACES IN REACTIVE COLLISIONS

    OpenAIRE

    Telle, H.

    1985-01-01

    For the investigation of unstable intermediates, ABC*, which constitute the "transition states" in some simple reactive collisions, spectroscopic methods are beginning to provide valuable results. In a (relatively) simple approach molecules are photodissociated, and the interaction potentials during the process of separation (half-collision) are mapped in either absorption or emission ; the method will be described exemplary for the photolysis of NaI, giving rise to emission from NaI≠*. For r...

  2. Electrohydrodynamics of binary electrolytes driven by modulated surface potentials

    DEFF Research Database (Denmark)

    Mortensen, Asger; Olesen, Laurits Højgaard; Belmon, L.;

    2005-01-01

    problem and obtain analytic solutions in the bulk for the pressure and velocity fields of the electrolyte and for the electric potential. We find good agreement between the numerics of the full problem and the analytics of the linear theory. Our work provides the theoretical foundations of circuit models...... discussed in the literature. The nonequilibrium approach also reveals unexpected high-frequency dynamics not predicted by circuit models....

  3. Negative plasma potential relative to electron-emitting surfaces.

    Science.gov (United States)

    Campanell, M D

    2013-09-01

    Most works on plasma-wall interaction predict that with strong electron emission, a nonmonotonic "space-charge-limited" (SCL) sheath forms where the plasma potential is positive relative to the wall. We show that a fundamentally different sheath structure is possible where the potential monotonically increases toward a positively charged wall that is shielded by a single layer of negative charge. No ion-accelerating presheath exists in the plasma and the ion wall flux is zero. An analytical solution of the "inverse sheath" regime is demonstrated for a general plasma-wall system where the plasma electrons and emitted electrons are Maxwellian with different temperatures. Implications of the inverse sheath effect are that (a) the plasma potential is negative, (b) ion sputtering vanishes, (c) no charge is lost at the wall, and (d) the electron energy flux is thermal. To test empirically what type of sheath structure forms under strong emission, a full plasma bounded by strongly emitting walls is simulated. It is found that inverse sheaths form at the walls and ions are confined in the plasma. This result differs from past particle-in-cell simulation studies of emission which contain an artificial "source sheath" that accelerates ions to the wall, leading to a SCL sheath at high emission intensity.

  4. Results of ground-water, surface-water, and water-chemistry monitoring, Black Mesa area, northeastern Arizona, 1994

    Science.gov (United States)

    Littin, G.R.; Monroe, S.A.

    1995-01-01

    The Black Mesa monitoring program is designed to document long-term effects of ground-water pumping from the N aquifer by industrial and municipal users. The N aquifer is the major source of water in the 5,400-square-mile Black Mesa area, and the ground water occurs under confined and unconfined conditions. Monitoring activities include continuous and periodic measurements of (1) ground-water pumpage from the confined and unconfined areas of the aquifer, (2) ground-water levels in the confined and unconfined areas of the aquifer, (3) surface-water discharge, and (4) chemistry of the ground water and surface water. In 1994, ground-water withdrawals for industrial and municipal use totaled about 7,000 acre-feet, which is an 8-percent increase from the previous year. Pumpage from the confined part of the aquifer increased by about 9 percent to 5,400 acre-feet, and pumpage from the unconfined part of the aquifer increased by about 2 percent to 1,600 acre-feet. Water-level declines in the confined area during 1994 were recorded in 10 of 16 wells, and the median change was a decline of about 2.3 feet as opposed to a decline of 3.3 feet for the previous year. The median change in water levels in the unconfined area was a rise of 0.1 foot in 1994 as opposed to a decline of 0.5 foot in 1993. Measured low-flow discharge along Moenkopi Wash decreased from 3.0 cubic feet per second in 1993 to 2.9 cubic feet per second in 1994. Eleven low-flow measurements were made along Laguna Creek between Tsegi, Arizona, and Chinle Wash to determine the amount of discharge that would occur as seepage from the N aquifer under optimal base-flow conditions. Discharge was 5.6 cubic feet per second near Tsegi and 1.5 cubic feet per second above the confluence with Chinle Wash. Maximum discharge was 5.9 cubic feet per second about 4 miles upstream from Dennehotso. Discharge was measured at three springs. The changes in discharge at Burro and Whisky Springs were small and within the uncertainty of

  5. Mapping ground surface deformation using temporarily coherent point SAR interferometry: Application to Los Angeles Basin

    Science.gov (United States)

    Zhang, L.; Lu, Zhiming; Ding, X.; Jung, H.-S.; Feng, G.; Lee, C.-W.

    2012-01-01

    Multi-temporal interferometric synthetic aperture radar (InSAR) is an effective tool to detect long-term seismotectonic motions by reducing the atmospheric artifacts, thereby providing more precise deformation signal. The commonly used approaches such as persistent scatterer InSAR (PSInSAR) and small baseline subset (SBAS) algorithms need to resolve the phase ambiguities in interferogram stacks either by searching a predefined solution space or by sparse phase unwrapping methods; however the efficiency and the success of phase unwrapping cannot be guaranteed. We present here an alternative approach - temporarily coherent point (TCP) InSAR (TCPInSAR) - to estimate the long term deformation rate without the need of phase unwrapping. The proposed approach has a series of innovations including TCP identification, TCP network and TCP least squares estimator. We apply the proposed method to the Los Angeles Basin in southern California where structurally active faults are believed capable of generating damaging earthquakes. The analysis is based on 55 interferograms from 32 ERS-1/2 images acquired during Oct. 1995 and Dec. 2000. To evaluate the performance of TCPInSAR on a small set of observations, a test with half of interferometric pairs is also performed. The retrieved TCPInSAR measurements have been validated by a comparison with GPS observations from Southern California Integrated GPS Network. Our result presents a similar deformation pattern as shown in past InSAR studies but with a smaller average standard deviation (4.6. mm) compared with GPS observations, indicating that TCPInSAR is a promising alternative for efficiently mapping ground deformation even from a relatively smaller set of interferograms. ?? 2011.

  6. Forward Modeling and validation of a new formulation to compute self-potential signals associated with ground water flow

    Directory of Open Access Journals (Sweden)

    A. Bolève

    2007-10-01

    Full Text Available The classical formulation of the coupled hydroelectrical flow in porous media is based on a linear formulation of two coupled constitutive equations for the electrical current density and the seepage velocity of the water phase and obeying Onsager's reciprocity. This formulation shows that the streaming current density is controlled by the gradient of the fluid pressure of the water phase and a streaming current coupling coefficient that depends on the so-called zeta potential. Recently a new formulation has been introduced in which the streaming current density is directly connected to the seepage velocity of the water phase and to the excess of electrical charge per unit pore volume in the porous material. The advantages of this formulation are numerous. First this new formulation is more intuitive not only in terms of establishing a constitutive equation for the generalized Ohm's law but also in specifying boundary conditions for the influence of the flow field upon the streaming potential. With the new formulation, the streaming potential coupling coefficient shows a decrease of its magnitude with permeability in agreement with published results. The new formulation has been extended in the inertial laminar flow regime and to unsaturated conditions with applications to the vadose zone. This formulation is suitable to model self-potential signals in the field. We investigate infiltration of water from an agricultural ditch, vertical infiltration of water into a sinkhole, and preferential horizontal flow of ground water in a paleochannel. For the three cases reported in the present study, a good match is obtained between finite element simulations performed and field observations. Thus, this formulation could be useful for the inverse mapping of the geometry of groundwater flow from self-potential field measurements.

  7. Geology and ground water in Door County, Wisconsin, with emphasis on contamination potential in the Silurian Dolomite

    Science.gov (United States)

    Sherrill, Marvin G.

    1978-01-01

    is thin or absent. Transmissivity values range from a low of 4.0 feet squared per day in the Niagaran aquifer near Sturgeon Bay to more than 13 000 feet squared per day for the Alexandrian aquifer near Fish Creek. Water from Silurian dolomite is a very hard calcium magnesium bicarbonate type, with objectionable concentrations of iron and nitrate in water from some wells. Sanitary quality, as indicated by tests for total coliform bacteria, has been a chronic problem in certain areas. Concentrations of indicator organisms are greatest during or immediately after rapid ground-water recharge, with concentrations rapidly decreasing after periods of recharge. Wells close to septic systems and in areas underlain by fractured near-surface bedrock have the greatest incidence of contamination. The type and thickness of unconsolidated material has a direct effect on the entry of bacteria into the ground-water system. Bacterial attenuation increases with increasing soil depth and reduction in soil permeability. After bacterial contaminants reach the water table within fractured bedrock, little attenuation occurs, and the contaminants can travel long distances in a short time. Ground water of good sanitary quality but exceeding recommended limits of the U.S. Public Health Service for sulfate and chloride is probably available from the sandstone aquifer by drilling wells 700 to 1300 feet deep. To minimize the possibility of obtaining contaminated ground water, well construction should include properly locating the wells upgradient and as far as practical from contamination sources, setting and pressure grouting well casings to an adequate depth into firm bedrock, and casing the well into the zone of saturation.

  8. Chromium speciation and fractionation in ground and surface waters in the vicinity of chromite ore processing residue disposal sites.

    Science.gov (United States)

    Farmer, John G; Thomas, Rhodri P; Graham, Margaret C; Geelhoed, Jeanine S; Lumsdon, David G; Paterson, Edward

    2002-04-01

    Chromium concentrations of up to 91 mg l(-1) were found by ICP-OES for ground water from nine boreholes at four landfill sites in an area of S.E. Glasgow/S. Lanarkshire where high-lime chromite ore processing residue (COPR) from a local chemical works had been deposited from 1830 to 1968. Surface water concentrations of up to 6.7 mg l(-1) in a local tributary stream fell to 0.11 mg l(-1) in the River Clyde. Two independent techniques of complexation/colorimetry and speciated isotope dilution mass spectrometry (SIDMS) showed that Cr was predominantly (>90%) in hexavalent form (CrVI) as CrO4(2-), as anticipated at the high pH (7.5-12.5) of the sites. Some differences between the implied and directly determined concentrations of dissolved CrIII, however, appeared related to the total organic carbon (TOC) content. This was most significant for the ground water from one borehole that had the highest TOC concentration of 300 mg l(-1) and at which ultrafiltration produced significant decreases in Cr concentration with decreasing size fractions, e.g. complex. This showed for the main Cr-containing fraction, 100 kDa-0.45 microm, that the Cr was associated with a dark brown band characteristic of organic (humic) matter. Comparison of gel electrophoresis and FTIR results for ultrafilter retentates of ground water from this borehole with those for a borehole at another site where CrVI predominated suggested the influence of carboxylate groups, both in reducing CrVI and in forming soluble CrIII-humic complexes. The implications of this for remediation strategies (especially those based on the addition of organic matter) designed to reduce highly mobile and carcinogenic Cr(VI)O4(2-) to the much less harmful CrIII as insoluble Cr(OH)3 are discussed.

  9. The study of coastal ground surfaces to predict the ways of increasing efficiency of research mobile robots

    Science.gov (United States)

    Makarov, Vladimir; Kurkin, Andrey; Belyalov, Vladimir; Tyugin, Dmitry; Zezyulin, Denis

    2017-04-01

    The increase in spatial scales of studying coastal areas can be achieved by the use of mobile robotic systems (MRS) equipped with scanning equipment, video inspection system and positioning system. The project aims at increasing the capabilities for designing effective ground MRS through the use of advanced methods of forecasting characteristics of vehicle-terrain interaction in coastal zones, where hydrosphere, lithosphere, atmosphere and biosphere interact. In the period from 14 May to 18 June 2016 there was organized the expedition to Sakhalin Island for conducting full-scale testing autonomous MRS for coastal monitoring and forecasting marine natural disasters [Kurkin A.A., Zeziulin D.V., Makarov V.S., Zaitsev A.I., Belyaev A.M., Beresnev P.O., Belyakov V.V., Pelinovsky E.N., Tyugin D.Yu. Investigations of coastal areas of the Okhotsk sea using a ground mobile robot // Ecological systems and devices. 2016. No. 8. P. 11-17]. Within the framework of the expedition specific areas of terrain in the vicinity of Cape Svobodny were investigated (with the support of SRB AMR FEB RAS). Terrain areas were studied from the standpoint of possibility of the MRS movement. As a result of measuring all the necessary data on the physical-mechanical and geometric characteristics of the coastal zones, required to calculate the force factors acting on the MRS, and, accordingly, the parameters of its motion were received. The obtained data will be used for developing new statistical models of the physical-mechanical and geometrical characteristics of the coastal ground surfaces, creating methodology for assessing the efficiency and finding ways to optimize the design of the MRS.

  10. The effects of oxalate treatment on the smear layer of ground surfaces of human dentine.

    Science.gov (United States)

    Pashley, D H; Galloway, S E

    1985-01-01

    The layer was evaluated by scanning electron microscopy and by measurement of hydraulic conductance before and after 2-min topical treatment with potassium chloride, neutral potassium oxalate, half-neutralized oxalic acid or both neutral and acidic oxalates. The treated smear layers were then re-evaluated microscopically and functionally both before and after acid challenge. The layers treated with KCl were not altered either microscopically or functionally and were susceptible to acid etching. Dentine surfaces treated with either oxalate solutions became less permeable and were acid-resistant.

  11. Pesticide levels in ground and surface waters of Primavera do Leste Region, Mato Grosso, Brazil.

    Science.gov (United States)

    Dores, Eliana F G C; Carbo, Leandro; Ribeiro, Maria L; De-Lamonica-Freire, Ermelinda M

    2008-08-01

    Residues of the herbicides simazine, metribuzin, metolachlor, trifluralin, atrazine, and two metabolites of atrazine, deisopropylatrazine (DIA) and deethylatrazine (DEA), are surveyed in the surface and groundwater of the Primavera do Leste region, Mato Grosso, Brazil during September and December 1998 and April 1999. Different water source sampling stations of groundwater (irrigation water well, drinking water well, and water hole) and surface water (dam and river) are set up based on agricultural land use. A solid-phase extraction procedure followed by gas chromatography-nitrogen-phosphorus detection is used for the determination of these compounds. All compounds are detected at least once in water samples. A temporal trend of pesticide contamination is observed, with the highest contamination frequency occurring in December during the main application season. Metribuzin shows the highest individual detection frequencies throughout the monitoring period, followed by metolachlor, simazine, and DEA. The maximum mean concentrations of pesticides in this study are in the range from 0.14 to 1.7 microg/L. We deduct that the contamination of water resources is predominantly caused by non-point pollution of pesticides used in intensive cash-crop cultures of the Cerrado area. Therefore, a continuous monitoring of pesticide concentrations in water resources of this tropical region is necessary to detect the longer term contamination trends and developing health risks.

  12. Potential surface for the collinear collision of Ne and H/sub 2//sup +/. [eendoergicity, surface parametrization

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, E.F.; Siu, A.K.Q.; Chapman, F.M. Jr.; Matcha, R.L.

    1976-09-01

    A potential energy surface for the Ne--H/sub 2//sup +/ reaction has been obtained in the LCAO--MO--SCF approximation. Analysis of the surface indicates that the reaction Ne+H/sub 2//sup +/..-->..NeH/sup +/+H should proceed with an endoergicity of 12 kcal/mole, in agreement with the experimental results of Chupka and Russell. Several procedures for parameterizing a diatomics-in-molecules (DIM) representation of the NeH/sub 2//sup +/ surface are considered. The results show that an accurate representation of the SCF surface can be obtained from the DIM model using a minimum of diatomic and triatomic data. (AIP)

  13. A study of SO2 emissions and ground surface displacements at Lastarria volcano, Antofagasta Region, Northern Chile

    Science.gov (United States)

    Krewcun, Lucie G.

    Lastarria volcano (Chile) is located at the North-West margin of the 'Lazufre' ground inflation signal (37x45 km2), constantly uplifting at a rate of ˜2.5 cm/year since 1996 (Pritchard and Simons 2002; Froger et al. 2007). The Lastarria volcano has the double interest to be superimposed on a second, smaller-scale inflation signal and to be the only degassing area of the Lazufre signal. In this project, we compared daily SO2 burdens recorded by AURA's OMI mission for 2005-2010 with Ground Surface Displacements (GSD) calculated from the Advanced Synthetic Aperture Radar (ASAR) images for 2003-2010. We found a constant maximum displacement rate of 2.44 cm/year for the period 2003-2007 and 0.80- 0.95 cm/year for the period 2007-2010. Total SO 2 emitted is 67.0 kT for the period 2005-2010, but detection of weak SO2 degassing signals in the Andes remains challenging owing to increased noise in the South Atlantic radiation Anomaly region.

  14. Intermolecular potential energy surface and thermophysical properties of ethylene oxide

    Energy Technology Data Exchange (ETDEWEB)

    Crusius, Johann-Philipp, E-mail: johann-philipp.crusius@uni-rostock.de; Hassel, Egon [Lehrstuhl für Technische Thermodynamik, Universität Rostock, 18059 Rostock (Germany); Hellmann, Robert; Bich, Eckard [Institut für Chemie, Universität Rostock, 18059 Rostock (Germany)

    2014-10-28

    A six-dimensional potential energy hypersurface (PES) for two interacting rigid ethylene oxide (C{sub 2}H{sub 4}O) molecules was determined from high-level quantum-chemical ab initio calculations. The counterpoise-corrected supermolecular approach at the MP2 and CCSD(T) levels of theory was utilized to determine interaction energies for 10178 configurations of two molecules. An analytical site-site potential function with 19 sites per ethylene oxide molecule was fitted to the interaction energies and fine tuned to agree with data for the second acoustic virial coefficient from accurate speed of sound measurements. The PES was validated by computing the second virial coefficient, shear viscosity, and thermal conductivity. The values of these properties are substantiated by the best experimental data as they tend to fall within the uncertainty intervals and also obey the experimental temperature functions, except for viscosity, where experimental data are insufficient. Due to the lack of reliable data, especially for the transport properties, our calculated values are currently the most accurate estimates for these properties of ethylene oxide.

  15. Simultaneous retrieval of aerosol and surface optical properties from combined airborne- and ground-based direct and diffuse radiometric measurements

    Directory of Open Access Journals (Sweden)

    C. K. Gatebe

    2009-12-01

    Full Text Available This paper presents a new method for simultaneously retrieving aerosol and surface reflectance properties from combined airborne and ground-based direct and diffuse radiometric measurements. The method is based on the standard Aerosol Robotic Network (AERONET method for retrieving aerosol size distribution, complex index of refraction, and single scattering albedo, but modified to retrieve aerosol properties in two layers, below and above the aircraft, and parameters on surface optical properties from combined datasets (Cloud Absorption Radiometer, CAR, and AERONET data. A key advantage of this method is the inversion of all available spectral and angular data at the same time, while accounting for the influence of noise in the inversion procedure using statistical optimization. The wide spectral (0.34–2.30 μm and angular range (180° of the CAR instrument, combined with observations from an AERONET sunphotometer, provide sufficient measurement constraints for characterizing aerosol and surface properties with minimal assumptions. The robustness of the method was tested on observations made during four different field campaigns: (a the Southern African Regional Science Initiative 2000 over Mongu, Zambia, (b the Intercontinental Transport Experiment-Phase B over Mexico City, Mexico (c Cloud and Land Surface Interaction Campaign over the Atmospheric Radiation Measurement (ARM Central Facility, Oklahoma, USA, and (d the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS over Elson Lagoon in Barrow, Alaska, USA. The four areas are dominated by different surface characteristics and aerosol types, and therefore provide good test cases for the new inversion method.

  16. Simultaneous retrieval of aerosol and surface optical properties from combined airborne- and ground-based direct and diffuse radiometric measurements

    Directory of Open Access Journals (Sweden)

    C. K. Gatebe

    2010-03-01

    Full Text Available This paper presents a new method for simultaneously retrieving aerosol and surface reflectance properties from combined airborne and ground-based direct and diffuse radiometric measurements. The method is based on the standard Aerosol Robotic Network (AERONET method for retrieving aerosol size distribution, complex index of refraction, and single scattering albedo, but modified to retrieve aerosol properties in two layers, below and above the aircraft, and parameters on surface optical properties from combined datasets (Cloud Absorption Radiometer (CAR and AERONET data. A key advantage of this method is the inversion of all available spectral and angular data at the same time, while accounting for the influence of noise in the inversion procedure using statistical optimization. The wide spectral (0.34–2.30 μm and angular range (180° of the CAR instrument, combined with observations from an AERONET sunphotometer, provide sufficient measurement constraints for characterizing aerosol and surface properties with minimal assumptions. The robustness of the method was tested on observations made during four different field campaigns: (a the Southern African Regional Science Initiative 2000 over Mongu, Zambia, (b the Intercontinental Transport Experiment-Phase B over Mexico City, Mexico (c Cloud and Land Surface Interaction Campaign over the Atmospheric Radiation Measurement (ARM Central Facility, Oklahoma, USA, and (d the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS over Elson Lagoon in Barrow, Alaska, USA. The four areas are dominated by different surface characteristics and aerosol types, and therefore provide good test cases for the new inversion method.

  17. Assessment of dry season surface, ground, and treated water quality in the Cape Coast municipality of Ghana.

    Science.gov (United States)

    Quagraine, E K; Adokoh, C K

    2010-01-01

    This aim of this monitoring was to assess water quality in a dry season for the Cape Coast municipality in Ghana, which has been experiencing chronic water shortages. Fifteen different sampling stations--four surface, five ground, and six tap water samples--were analyzed for physicochemical and microbiological parameters during January to April 2005. Levels or trends in water quality that may be deleterious to sensitive water uses, including drinking, irrigation, and livestock watering have been noted with reference to well-established guidelines. Exceedances to some health-based drinking water guidelines included positive coliform for various water samples; pH for all groundwater samples (pH 5.9+/-0.3); conductivity for 50% groundwater; color for about a third of groundwater and tap water; Mn for 44% tap water, 67% groundwater, and 50% surface water samples. The World Health Organization laundry staining Fe guideline of 0.3 mg/l was exceeded by 75% of surface water, 44% tap water, and 53% groundwater samples. The corresponding Mn guideline of 0.1 mg/l was exceeded by all the water samples. Respectively, all surface water samples and also 75% of the surface water exceeded some known Cu and Zn guideline for the protection of aquatic life. Compared to some historic data for Fosu Lagoon, the current study shows a lowering of approximately 1 pH unit, increase of approximately 65% NH3, one to two orders of magnitude increase in PO4(3-), and more than two orders of magnitude increase in NO3-. In several instances, tap water samples collected at the consumers' end of the distribution system did not reflect on the true quality of the treated water. Mn, SO4(2-), PO4(3-), Cu, and Zn were among the chemical contaminations observed to occur in the distribution system.

  18. Areal-averaged and Spectrally-resolved Surface Albedo from Ground-based Transmission Data Alone: Toward an Operational Retrieval

    Energy Technology Data Exchange (ETDEWEB)

    Kassianov, Evgueni I.; Barnard, James C.; Flynn, Connor J.; Riihimaki, Laura D.; Michalsky, Joseph; Hodges, G. B.

    2014-08-22

    We present here a simple retrieval of the areal-averaged and spectrally resolved surface albedo using only ground-based measurements of atmospheric transmission under fully overcast conditions. Our retrieval is based on a one-line equation and widely accepted assumptions regarding the weak spectral dependence of cloud optical properties in the visible and near-infrared spectral range. The feasibility of our approach for the routine determinations of albedo is demonstrated for different landscapes with various degrees of heterogeneity using three sets of measurements:(1) spectrally resolved atmospheric transmission from Multi-Filter Rotating Shadowband Radiometer (MFRSR) at wavelength 415, 500, 615, 673, and 870 nm, (2) tower-based measurements of local surface albedo at the same wavelengths, and (3) areal-averaged surface albedo at four wavelengths (470, 560, 670 and 860 nm) from collocated and coincident Moderate Resolution Imaging Spectroradiometer (MODIS) observations. These integrated datasets cover both long (2008-2013) and short (April-May, 2010) periods at the ARM Southern Great Plains (SGP) site and the NOAA Table Mountain site, respectively. The calculated root mean square error (RMSE), which is defined here as the root mean squared difference between the MODIS-derived surface albedo and the retrieved area-averaged albedo, is quite small (RMSE≤0.01) and comparable with that obtained previously by other investigators for the shortwave broadband albedo. Good agreement between the tower-based daily averages of surface albedo for the completely overcast and non-overcast conditions is also demonstrated. This agreement suggests that our retrieval originally developed for the overcast conditions likely will work for non-overcast conditions as well.

  19. Dynamic subsidence prediction of ground surface above salt cavern gas storage considering the creep of rock salt

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A new model is proposed to predict the dynamic subsidence of ground surface above salt cavern gas storage during the leaching and storage, which takes into account the creep of rock salt. In the model, the extended form of Gaussian curve is adopted to figure out the shape of subsidence areas. The corresponding theoretical formulas are derived. In addition, parameters are studied to investigate the surface subsidence as a function of the salt ejection rate, internal pressure, buried depth, diameter, height, running time, etc. Through an example, the subsidence of the salt cavern gas storage located at Jiangsu of China obtained by the new model was compared with those by Peter A F formula, Schober & Sroka formula and FLAC3D through simulation. The results showed the proposed model is precise and correct, and can meet the actual engineering demands. The surface subsidence is equidirectional with the increase of salt ejection rate, depth, diameter, height, and running time, but reverse to the increase of internal pressure. The depth, diameter, running time and internal pressure have great effects on the subsidence, whereas the salt ejection rate and height have little influences on it.

  20. 3D Printed Potential and Free Energy Surfaces for Teaching Fundamental Concepts in Physical Chemistry

    Science.gov (United States)

    Kaliakin, Danil S.; Zaari, Ryan R.; Varganov, Sergey A.

    2015-01-01

    Teaching fundamental physical chemistry concepts such as the potential energy surface, transition state, and reaction path is a challenging task. The traditionally used oversimplified 2D representation of potential and free energy surfaces makes this task even more difficult and often confuses students. We show how this 2D representation can be…

  1. Hydro-economic modeling of conjunctive ground and surface water use to guide sustainable basin management

    Science.gov (United States)

    Taher Kahil, Mohamed; Ward, Frank A.; Albiac, Jose; Eggleston, Jack; Sanz, David

    2016-04-01

    Water demands for irrigation, urban and environmental uses in arid and semiarid regions continue to grow, while freshwater supplies from surface and groundwater resources are becoming scarce and are expected to decline with climate change. Policymakers in these regions face hard choices on water management and policies. Hydro-economic modeling is the state-of-the art tool that could be used to guide the design and implementation of sustainable water management policies in basins. The strength of hydro-economic modeling lies in its capacity to integrate key biophysical and socio-economic components within a unified framework. A major gap in developments on hydro-economic modeling to date has been the weak integration of surface and groundwater flows, based on the theoretically correct Darcy equations used by the hydrogeological community. The modeling approach taken here is integrated, avoiding the single-tank aquifer assumption, avoiding simplified assumptions on aquifer-river linkages, and bypassing iterations among separate hydrological and economic models. The groundwater flow formulation used in this paper harnesses the standard finite difference expressions for groundwater flow and groundwater-surface water exchange developed in the USGS MODFLOW groundwater model. The methodological contribution to previous modeling efforts is the explicit specification of aquifer-river interactions, important when aquifer systems make a sizable contribution to basin resources. The modeling framework is solved completely, and information among the economic and hydrological components over all periods and locations are jointly and simultaneously determined. This novel framework is applied to the Jucar basin (Spain), which is a good experimental region for an integrated basin scale analysis. The framework is used for assessing the impacts of a range of climate change scenarios and policy choices, especially the hydrologic, land use, and economic outcomes. The modeling framework

  2. A feasibility study to estimate minimum surface-casing depths of oil and gas wells to prevent ground-water contamination in four areas of western Pennsylvania

    Science.gov (United States)

    Buckwalter, T.F.; Squillace, P.J.

    1995-01-01

    Hydrologic data were evaluated from four areas of western Pennsylvania to estimate the minimum depth of well surface casing needed to prevent contamination of most of the fresh ground-water resources by oil and gas wells. The areas are representative of the different types of oil and gas activities and of the ground-water hydrology of most sections of the Appalachian Plateaus Physiographic Province in western Pennsylvania. Approximate delineation of the base of the fresh ground-water system was attempted by interpreting the following hydrologic data: (1) reports of freshwater and saltwater in oil and gas well-completion reports, (2) water well-completion reports, (3) geophysical logs, and (4) chemical analyses of well water. Because of the poor quality and scarcity of ground-water data, the altitude of the base of the fresh ground-water system in the four study areas cannot be accurately delineated. Consequently, minimum surface-casing depths for oil and gas wells cannot be estimated with confidence. Conscientious and reliable reporting of freshwater and saltwater during drilling of oil and gas wells would expand the existing data base. Reporting of field specific conductance of ground water would greatly enhance the value of the reports of ground water in oil and gas well-completion records. Water-bearing zones in bedrock are controlled mostly by the presence of secondary openings. The vertical and horizontal discontinuity of secondary openings may be responsible, in part, for large differences in altitudes of freshwater zones noted on completion records of adjacent oil and gas wells. In upland and hilltop topographies, maximum depths of fresh ground water are reported from several hundred feet below land surface to slightly more than 1,000 feet, but the few deep reports are not substantiated by results of laboratory analyses of dissolved-solids concentrations. Past and present drillers for shallow oil and gas wells commonly install surface casing to below the

  3. Ground-water-level monitoring, basin boundaries, and potentiometric surfaces of the aquifer system at Edwards Air Force Base, California, 1992

    Science.gov (United States)

    Rewis, D.L.

    1995-01-01

    A ground-water-level monitoring program was implemented at Edwards Air Force Base, California, from January through December 1992 to monitor spatial and temporal changes in poten-tiometric surfaces that largely are affected by ground-water pumping. Potentiometric-surface maps are needed to determine the correlation between declining ground- water levels and the distribution of land subsidence. The monitoring program focused on areas of the base where pumping has occurred, especially near Rogers Lake, and involved three phases of data collection: (1) well canvassing and selection, (2) geodetic surveys, and (3) monthly ground-water-level measurements. Construction and historical water- level data were compiled for 118 wells and pi-ezometers on or near the base, and monthly ground-water-level measurements were made in 82 wells and piezometers on the base. The compiled water-level data were used in conjunction with previously collected geologic data to identify three types of no-flow boundaries in the aquifer system: structural boundaries, a principal-aquifer boundary, and ground-water divides. Heads were computed from ground-water-level measurements and land-surface altitudes and then were used to map seasonal potentiometric surfaces for the principal and deep aquifers underlying the base. Pumping has created a regional depression in the potentiometric surface of the deep aquifer in the South Track, South Base, and Branch Park well-field area. A 15-foot decline in the potentiometric surface from April to September 1992 and 20- to 30-foot drawdowns in the three production wells in the South Track well field caused locally unconfined conditions in the deep aquifer.

  4. Application of ESPRIT in Broad Beam HF Ground Wave Radar Sea Surface Current Mapping

    Institute of Scientific and Technical Information of China (English)

    Liu Dan-hong; Wu Xiong-bin; Wen Bi-yang; Cheng Feng

    2004-01-01

    HF surface wave radar system OSMAR2000 is a broad-beam sea-state detecting radar. ESPRIT (Estimation of Signal Parameters via Rotational Invariance Technique) algorithm is proposed to apply in DOA (direction of arrival) determination of sea echoes. The algorithm of ESPRIT is briefly introduced first. Then discussions are made on the technique for application in the OSMAR2000 framework. Numerical simulation results are presented to demonstrate the feasibility of radial current mapping based on this method. The algorithm manifests significant performance and computational advantages compared with that of MUSIC. Data acquired by OSMAR2000 are processed to give radial current map and the synthesized vector currents are compared with the in-situ measurement with traditional means. The results show the validity of ESPRIT application in DOA determination for broad-beam radar.

  5. W-Band Characterization of Grounded Frequency Selective Surface Arrays Composed of Nonequal Slot Length Subarrays

    Directory of Open Access Journals (Sweden)

    S. Islam

    2009-01-01

    Full Text Available We present the design and construction of Frequency Selective Surface arrays composed of two subarrays of different slot lengths. We investigated their response variations with the variation of slot length differences of the elementary sub-arrays. Such nonhomogeneous arrays cannot be simulated with Computer Aided Design (CAD programs because the boundary conditions are not fulfilled by the simulator. In infinite array simulation, the periodic boundary conditions are prescribed on the walls of the unit cell, whereas in the case of sub-arrays of unequal slot length such boundary conditions are not applicable. The CAD simulation of such combined array gives incorrect values of amplitude and phase responses. In this work, we investigate the characteristics of such complex arrays by using heuristic experimental approach. The results of the experimental approach demonstrate that the resultant reflection amplitude and phase of such complex array depend on the difference of slot lengths (ΔL of the two sub-arrays.

  6. Study of the Dependence Effectiveness of Low-potential Heat of the Ground and Atmospheric Air for Heating Buildings from Climatic parameters

    Directory of Open Access Journals (Sweden)

    Vasilyev Gregory P.

    2016-01-01

    Full Text Available The article represents the results of researches for division into districts of the territory of Russia and Europe by efficiency of using for the heat supply of buildings of low-potential thermal energy of ground and free air and their combination. While modeling of the heat regime of geothermal HPS in climatic conditions of different regions of the territory of Russia, the influence has been taken into account of the long-term extraction of geothermal heat energy on the ground heat regime as well as the influence of phase transitions of pore moisture in ground on the efficiency of operation of geothermal heat-pump heat-supply systems. While realization of the division into districts, the sinking of temperatures of ground massive was been taken into account which has been called by long-term extraction of the heat energy from the ground, and as calculation parameters of the heat energy from the ground, and as calculation parameters of ground massive temperatures, the ground temperatures were used which are waited for the 5-th year of operation of geothermal HPS.

  7. Analytical approximation of the InGaZnO thin-film transistors surface potential

    Science.gov (United States)

    Colalongo, Luigi

    2016-10-01

    Surface-potential-based mathematical models are among the most accurate and physically based compact models of thin-film transistors, and in turn of indium gallium zinc oxide TFTs, available today. However, the need of iterative computations of the surface potential limits their computational efficiency and diffusion in CAD applications. The existing closed-form approximations of the surface potential are based on regional approximations and empirical smoothing functions that could result not accurate enough in particular to model transconductances and transcapacitances. In this work we present an extremely accurate (in the range of nV) and computationally efficient non-iterative approximation of the surface potential that can serve as a basis for advanced surface-potential-based indium gallium zinc oxide TFTs models.

  8. Surface and Ground Water Quality in Köprüören Basin (Kütahya), Turkey

    Science.gov (United States)

    Arslan, Şebnem; Çelik, Mehmet; Erdem Dokuz, Uǧur; Abadi Berhe, Berihu

    2014-05-01

    In this study, quality of the water resources in Köprüören Basin, located to the west of Kütahya city in western Anatolia, were investigated. The total catchment area of the basin is 275 km2 and it is located upstream of Kütahya and Eskişehir plains. Therefore, besides 6,000 people residing in the basin, a much larger population will be impacted by the quality of surface and groundwater resources. Groundwater occurs under confined conditions in the limestones of Pliocene units. Groundwater flow is from north to south and south to north towards Kocasu stream, which flows to Enne Dam. The surface and ground water quality in this area are negatively affected by the mining activities. In the northern part of the area, there are coal deposits present in Miocene Tunçbilek formation. Ground waters in contact with the coal deposits contain low concentrations of arsenic (up to 30 µg/l). In the southern part, the only silver deposit of Turkey is present, which is developed in metamorphic basement rocks, Early Miocene volcanics and Pliocene units near Gümüşköy (Gümüş means silver, köy means village in Turkish). The amount of silver manufactured annually in this silver plant is huge and comprises about 1% of the World's Silver Production. The wastes, enriched in cyanide, arsenic, stibnite, lead and zinc, are stored in waste pools and there is extensive leakage of these heavy metals from these pools. Therefore, surface waters, soils and plants in the affected areas contain high concentrations of arsenic, stibnite and lead. The As, Sb, Pb and Zn concentrations are up to 733 µg/l, 158 µg/l, 48 µg/l, and 286 µg/l in surface waters (in dry season), 6180 ppm, 410 ppm, 4180 ppm, 9950 ppm in soils and 809 ppm, 399 ppm, 800 ppm, 2217 ppm in plants, respectively. Today, most of the As, Sb, Pb and Zn are absorbed by the soils and only a small part are dissolved in water. However, conditions might change in future leading to desorption of these contaminants. Therefore

  9. Ground level environmental protein concentrations in various ecuadorian environments: potential uses of aerosolized protein for ecological research

    Science.gov (United States)

    Staton, Sarah J.R.; Woodward, Andrea; Castillo, Josemar A.; Swing, Kelly; Hayes, Mark A.

    2014-01-01

    Large quantities of free protein in the environment and other bioaerosols are ubiquitous throughout terrestrial ground level environments and may be integrative indicators of ecosystem status. Samples of ground level bioaerosols were collected from various ecosystems throughout Ecuador, including pristine humid tropical forest (pristine), highly altered secondary humid tropical forest (highly altered), secondary transitional very humid forest (regrowth transitional), and suburban dry montane deforested (suburban deforested). The results explored the sensitivity of localized aerosol protein concentrations to spatial and temporal variations within ecosystems, and their value for assessing environmental change. Ecosystem specific variations in environmental protein concentrations were observed: pristine 0.32 ± 0.09 μg/m3, highly altered 0.07 ± 0.05 μg/m3, regrowth transitional 0.17 ± 0.06 μg/m3, and suburban deforested 0.09 ± 0.04 μg/m3. Additionally, comparisons of intra-environmental differences in seasonal/daily weather (dry season 0.08 ± 0.03 μg/m3 and wet season 0.10 ± 0.04 μg/m3), environmental fragmentation (buffered 0.19 ± 0.06 μg/m3 and edge 0.15 ± 0.06 μg/m3), and sampling height (ground level 0.32 ± 0.09 μg/m3 and 10 m 0.24 ± 0.04 μg/m3) demonstrated the sensitivity of protein concentrations to environmental conditions. Local protein concentrations in altered environments correlated well with satellite-based spectral indices describing vegetation productivity: normalized difference vegetation index (NDVI) (r2 = 0.801), net primary production (NPP) (r2 = 0.827), leaf area index (LAI) (r2 = 0.410). Moreover, protein concentrations distinguished the pristine site, which was not differentiated in spectral indices, potentially due to spectral saturation typical of highly vegetated environments. Bioaerosol concentrations represent an inexpensive method to increase understanding of environmental changes, especially in densely vegetated

  10. Understanding ship-grounding impacts on a coral reef: potential effects of anti-foulant paint contamination on coral recruitment.

    Science.gov (United States)

    Negri, Adrew P; Smith, Luke D; Webster, Nicole S; Heyward, Andrew J

    2002-02-01

    The 184 m cargo ship Bunga Teratai Satu collided with Sudbury Reef, part of the Great Barrier Reef and remained grounded for 12 days. The ship was re-floated only 3 days prior to the November 2000 mass coral spawning. No cargo or fuel was lost but the impact resulted in significant contamination of the reef with anti-foulant paint containing tributyltin (TBT), copper (Cu) and zinc (Zn). Larvae of the reef-building scleractinian coral Acropora microphthalma were exposed to various concentrations of sediment collected from the grounding site in replicated laboratory experiments. Two experiments were performed, both of which used varying ratios of contaminated and control site sediment in seawater as treatments. In the first experiment, the influence of contaminated sediment on larval competency was examined using metamorphosis bioassays. In the second, the effect of contaminated sediment upon larval recruitment on pre-conditioned terracotta tiles was assessed. In both experiments, sediment containing 8.0 mg kg(-1) TBT, 72 mg kg(-1) Cu and 92 mg kg(-1) Zn significantly inhibited larval settlement and metamorphosis. At this level of contamination larvae survived but contracted to a spherical shape and swimming and searching behaviour ceased. At higher contamination levels, 100% mortality was recorded. These results indicate that the contamination of sediment by anti-fouling paint at Sudbury Reef has the potential to significantly reduce coral recruitment in the immediate vicinity of the site and that this contamination may threaten the recovery of the resident coral community unless the paint is removed.

  11. High resolution imaging of vadose zone transport using surface and crosswell ground penetrating radar methods

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Kenneth H.; Kowalsky, Mike B.; Peterson, John E.

    2002-11-05

    To effectively clean up many contaminated sites there is a need for information on heterogeneities at scales ranging from one centimeter to tens of meters, as these features can alter contaminant transport significantly. At the Department of Energy's Hanford, Washington site heterogeneities of interest can range from localized phenomena such as silt or gravel lenses, fractures, clastic dikes, to large-scale lithologic discontinuities. In the vadose zone it is critical to understand the parameters controlling flow. These features have been suspected of leading to funneling and fingering, additional physical mechanisms that could alter and possibly accelerate the transport of contaminants to underlying groundwater. For example, it has been observed from the studies to date that over relatively short distances there are heterogeneities in the physical structure of the porous medium and structural differences between repacked soil cores and the field site from which the materials initially came (Raymond and Shdo, 1966). Analysis of cores taken from the vadose zone (i.e., soil surface to water table) has been useful in identifying localized zones of contamination. Unfortunately, these analyses are sparse (limited to a few boreholes) and extremely expensive. The high levels of radioactivity at many of the contaminated sites increase drilling and sample costs and analysis time. Cost of drilling and core analysis for the SX tank farm has exceeded $1M per borehole (50 meter deep) for sampling. The inability to track highly mobile species through the vadose zone highlights an important need: the need for methods to describe the complete vadose zone plume and to determine processes controlling accelerated contamination of groundwater at Hanford. A combination of surface and crosswell (i.e. borehole) geophysical measurements is one means to provide this information. The main questions addressed with the radar methods in this study are: (1) What parts of the vadose zone

  12. Estimating Daily Maximum and Minimum Land Air Surface Temperature Using MODIS Land Surface Temperature Data and Ground Truth Data in Northern Vietnam

    Directory of Open Access Journals (Sweden)

    Phan Thanh Noi

    2016-12-01

    Full Text Available This study aims to evaluate quantitatively the land surface temperature (LST derived from MODIS (Moderate Resolution Imaging Spectroradiometer MOD11A1 and MYD11A1 Collection 5 products for daily land air surface temperature (Ta estimation over a mountainous region in northern Vietnam. The main objective is to estimate maximum and minimum Ta (Ta-max and Ta-min using both TERRA and AQUA MODIS LST products (daytime and nighttime and auxiliary data, solving the discontinuity problem of ground measurements. There exist no studies about Vietnam that have integrated both TERRA and AQUA LST of daytime and nighttime for Ta estimation (using four MODIS LST datasets. In addition, to find out which variables are the most effective to describe the differences between LST and Ta, we have tested several popular methods, such as: the Pearson correlation coefficient, stepwise, Bayesian information criterion (BIC, adjusted R-squared and the principal component analysis (PCA of 14 variables (including: LST products (four variables, NDVI, elevation, latitude, longitude, day length in hours, Julian day and four variables of the view zenith angle, and then, we applied nine models for Ta-max estimation and nine models for Ta-min estimation. The results showed that the differences between MODIS LST and ground truth temperature derived from 15 climate stations are time and regional topography dependent. The best results for Ta-max and Ta-min estimation were achieved when we combined both LST daytime and nighttime of TERRA and AQUA and data from the topography analysis.

  13. Simultaneous investigation of blast induced ground vibration and airblast effects on safety level of structures and human in surface blasting

    Institute of Scientific and Technical Information of China (English)

    Faramarzi Farhad⇑; Ebrahimi Farsangi Mohammad Ali; Mansouri Hamid

    2014-01-01

    The significance of studying, monitoring and predicting blast induced vibration and noise level in mining and civil activities is justified in the capability of imposing damages, sense of uncertainty due to negative psychological impacts on involved personnel and also judicial complaints of local inhabitants in the nearby area. This paper presents achieved results during an investigation carried out at Sungun Copper Mine, Iran. Besides, the research also studied the significance of blast induced ground vibration and air-blast on safety aspects of nearby structures, potential risks, frequency analysis, and human response. According to the United States Bureau of Mines (USBM) standard, the attenuation equations were devel-oped using field records. A general frequency analysis and risk evaluation revealed that:94%of generated frequencies are less than 14 Hz which is within the natural frequency of structures that increases risk of damage. At the end, studies of human response showed destructive effects of the phenomena by ranging between 2.54 and 25.40 mm/s for ground vibrations and by the average value of 110 dB for noise levels which could increase sense of uncertainty among involved employees.

  14. Field experiment provides ground truth for surface nuclear magnetic resonance measurement

    Science.gov (United States)

    Knight, R.; Grunewald, E.; Irons, T.; Dlubac, K.; Song, Y.; Bachman, H.N.; Grau, B.; Walsh, D.; Abraham, J.D.; Cannia, J.

    2012-01-01

    The need for sustainable management of fresh water resources is one of the great challenges of the 21st century. Since most of the planet's liquid fresh water exists as groundwater, it is essential to develop non-invasive geophysical techniques to characterize groundwater aquifers. A field experiment was conducted in the High Plains Aquifer, central United States, to explore the mechanisms governing the non-invasive Surface NMR (SNMR) technology. We acquired both SNMR data and logging NMR data at a field site, along with lithology information from drill cuttings. This allowed us to directly compare the NMR relaxation parameter measured during logging,T2, to the relaxation parameter T2* measured using the SNMR method. The latter can be affected by inhomogeneity in the magnetic field, thus obscuring the link between the NMR relaxation parameter and the hydraulic conductivity of the geologic material. When the logging T2data were transformed to pseudo-T2* data, by accounting for inhomogeneity in the magnetic field and instrument dead time, we found good agreement with T2* obtained from the SNMR measurement. These results, combined with the additional information about lithology at the site, allowed us to delineate the physical mechanisms governing the SNMR measurement. Such understanding is a critical step in developing SNMR as a reliable geophysical method for the assessment of groundwater resources.

  15. Directional site resonances and the influence of near-surface geology on ground motion

    Science.gov (United States)

    Bonamassa, Ornella; Vidale, John E.; Houston, Heidi; Schwartz, Susan Y.

    1991-05-01

    We examine the horizontal motions at close stations from earthquakes in the Loma Prieta and Whittier Narrows sequences to study the shear wave polarizations. We use a dense, six station array recording 10 aftershocks for the former, and use two events and 11 stations across the Los Angeles area for the latter.We compute the average azimuth of strongest shaking in the shear wave as a function of frequency from 1 to 18 Hz for each record of each earthquake. The direction of shaking at a given frequency often correlates much better with an empirical site resonance direction than with the direction of shaking expected from the focal mechanism of the earthquake. The effect tends to be greatest at the frequencies that are the most amplified. This phenomenon can complicate determination of the earthquake source at frequencies higher than 1 Hz.Further, since sites only 25 meters apart show different preferred directions, very near-surface geology is probably responsible. Estimation of directional site resonances may prove useful for seismic design.

  16. Estimation of the near surface soil water content during evaporation using air-launched ground-penetrating radar

    KAUST Repository

    Moghadas, Davood

    2014-01-01

    Evaporation is an important process in the global water cycle and its variation affects the near sur-face soil water content, which is crucial for surface hydrology and climate modelling. Soil evaporation rate is often characterized by two distinct phases, namely, the energy limited phase (stage-I) and the soil hydraulic limited period (stage-II). In this paper, a laboratory experiment was conducted using a sand box filled with fine sand, which was subject to evaporation for a period of twenty three days. The setup was equipped with a weighting system to record automatically the weight of the sand box with a constant time-step. Furthermore, time-lapse air-launched ground penetrating radar (GPR) measurements were performed to monitor the evaporation process. The GPR model involves a full-waveform frequency-domain solution of Maxwell\\'s equations for wave propagation in three-dimensional multilayered media. The accuracy of the full-waveform GPR forward modelling with respect to three different petrophysical models was investigated. Moreover, full-waveform inversion of the GPR data was used to estimate the quantitative information, such as near surface soil water content. The two stages of evaporation can be clearly observed in the radargram, which indicates qualitatively that enough information is contained in the GPR data. The full-waveform GPR inversion allows for accurate estimation of the near surface soil water content during extended evaporation phases, when a wide frequency range of GPR (0.8-5.0 GHz) is taken into account. In addition, the results indicate that the CRIM model may constitute a relevant alternative in solving the frequency-dependency issue for full waveform GPR modelling.

  17. A New Method of Grounding Grid Design

    Directory of Open Access Journals (Sweden)

    Feng Zhen-Bao

    2016-01-01

    Full Text Available In order to equalize the electric potential distribution of the grounding grid surface, and improve the safety level of the grounding grid, method for optimal arrangement of conducts in the grounding grid is proposed in this paper. The calculation results about maximum touch voltages and mesh potentials show that the method can reduce touch voltage and equilibrium surface potential. It is shown that the design of the grounding grid is related to not only the soil environment, but also the rectangular shape. Comparing with other methods, the method proposed in the paper can reduce maximum touch voltage about 12%. This method also can be applied in a uniform and non-uniform soil, rectangular and square grounding grids. The optimize effect meets the related standards of the power industry.

  18. Sedimentary and water column processes in the Oyster Grounds: a potentially hypoxic region of the North Sea.

    Science.gov (United States)

    Weston, K; Fernand, L; Nicholls, J; Marca-Bell, A; Mills, D; Sivyer, D; Trimmer, M

    2008-04-01

    The purpose of this research was to investigate the potential causes of low oxygen levels in the bottom water of the Oyster Grounds region of the shallow southern North Sea, an area which provides suitable conditions for low oxygen levels to develop. At the end of the summer stratified period, relevant biogeochemical processes were investigated using a combination of sedimentary and water column rate measurements. Phytoplankton nitrate and ammonium uptake was measured throughout the water column using (15)N labelled isotopes and showed ammonium uptake dominated in the upper and bottom mixed layer with a maximum 294.4 micromol N m(-3)h(-1). In the deep chlorophyll maximum at the thermocline, primary production was dominated by nitrate uptake, with an average of 35.0 micromol N m(-3)h(-1), relative to ammonium uptake, with an average of 24.6 micromol N m(-3)h(-1). This high relative nitrate uptake will in part result in exportable new production to the isolated bottom mixed layer and sediments, as opposed to regenerated ammonium driven uptake. This biomass export was indicated by significant benthic oxygen consumption rates in the stratified region (782-1275 micromol O(2)m(-2)h(-1)micromol N m(-3)h(-1)) long after the end of the spring bloom. The sediments were also an active net source of nitrate, ammonium, phosphate and silicate into the bottom mixed layer of 4.4, 8.4, 2.3 and 68.8 micromol m(-2)h(-1), respectively. The export of new production within the thermocline to the bottom mixed layer and the consequent sediment oxygen consumption in the isolated bottom mixed layer in the Oyster Grounds are expected to have contributed to the low bottom water oxygen concentrations of 2.07 mg l(-1) (64.7 micromol l(-1)) measured. The long stratified period associated with this low oxygen is predicted to occur more regularly in the future and continued monitoring of this ecologically important region is therefore essential if the causes of these potentially damaging low

  19. Accuracy of Low-level Surface in Hierarchical Construction of Potential Energy Surface

    Institute of Scientific and Technical Information of China (English)

    Chun-rui Wang; Dong H. Zhang

    2012-01-01

    The effects of low-level PES on the overall accuracy of the final surface constructed by using hierarchical construction were investigated with the constructions of a number of global surfaces for the H3 system at UHF (UMP2,DFT-B3LYP,UCCSD(T))/vtz,and UCCSD(T)/avqz levels of theory.The total reaction probabilities for the H+H2 reaction calculated on these surfaces revealed that the accuracy of UCCSD(T)/avqz surface is very close to the well-known BKMP2 surface,while the UCCSD(T)/vtz PES has a slightly higher barrier.In contrast,the low-level theories (UHF,UMP2,DFT-B3LYP) with vtz basis set can only provide a qualitative description of this simplest reaction despite the fact that they are widely used to study reactions in complex systems.On the other hand,although these theories are not accurate on describing the reaction,they can be used to provide the lowlevel PESs for hierarchical construction of the UCCSD(T)/avqz PES with the number of UCCSD(T)/avqz energies substantially reduced.

  20. Geochemical background and ecological risk of heavy metals in surface sediments from the west Zhoushan Fishing Ground of East China Sea.

    Science.gov (United States)

    Xu, Gang; Liu, Jian; Pei, Shaofeng; Hu, Gang; Kong, Xianghuai

    2015-12-01

    Surface sediment grain size as well as the spatial distribution, pollution status, and source identification of heavy metals in the west Zhoushan Fishing Ground (ZFG) of the East China Sea were analyzed to study the geochemical background concentrations of heavy metals and to assess their potential ecological risk. Our results show that surface sediments in the eastern part of study area were mainly composed of sand-sized components. Spatial distributions of heavy metals were mainly controlled by grain size and terrigenous materials, and their concentrations in the coarsest grain sediments formed primarily during the Holocene transgressive period could represent the element background values of our study area. Contamination factor suggests that there was no pollution of Pb, Zn, and Cr generally in our study area and slight pollution of Cu, Cd, and As (especially Cu) at some stations. In addition, ecological harm coefficient indicates that the ecological risk of each heavy metal, except for Cd, at two stations was low as well. These results are consistent with the pollution load index and ecological risk index, which suggest both the overall level of pollution and the overall ecological risk of six studied metals in sediment were relatively low in our study area. Enrichment factor indicates that the heavy metals came mostly from the natural source. Summarily, the quality level of sediment in our study area was relatively good, and heavy metals in sediments could not exert threat to aquatic lives in the ZFG until now.

  1. A three-dimensional He-CO potential energy surface with improved long-range behavior

    Science.gov (United States)

    McBane, George C.

    2016-12-01

    A weakness of the ;CBS + corr; He-CO potential energy surface (Peterson and McBane, 2005) has been rectified by constraining the potential to adopt accurate long-range behavior for He-CO distances well beyond 15a0 . The resulting surface is very similar to the original in the main part of the interaction. Comparison with accurately known bound-state energies indicates that the surface is slightly improved in the region sampled by the highest lying bound states. The positions of shape and Feshbach resonances within a few cm-1 of the j = 1 excitation threshold are essentially unchanged. The low-energy scattering lengths changed noticeably. The revised surface generates a small negative limiting scattering length for collisions with 4He, while the original surface gave a small positive one. Both surfaces yield scattering lengths quite different from the widely used surface of Heijmen et al. (1997) for both He isotopes.

  2. Potential effects of surface coal mining on the hydrology of the Bloomfield coal tract, Dawson County, eastern Montana

    Science.gov (United States)

    Cannon, M.R.

    1983-01-01

    The Bloomfield coal tract in Dawson County, Montana, contains about 420 million tons of recoverable coal reserves within the Pust coal bed. About 136 million tons of coal within the tract is Federally owned, of which 98 million tons has been identified for potential lease sale. A hydrologic study has been conducted in the potential lease area to describe existing hydrologic systems and to assess potential impacts of surface coal mining on local water resources. Shallow ground-water resources in the tract are limited to sandstone and coal aquifers in the Tongue River Member of the Fort Union Formation (Paleocene age). These shallow aquifers have small values of hydraulic conductivity; yields to wells generally range from 1 to 10 gallons per minute. Water from shallow sandstone and coal aquifers is used primarily for livestock watering and domestic supply. Chemical analyses indicate that water from most shallow aquifers is dominated by calcium and magnesium cations and sulfate and bicarbonate anions. Surface-water resources in the tract consist primarily of small reservoirs used for livestock watering. All streams in the tract are ephemeral, making them unreliable as a source of livestock water. Mining of the Pust coal bed would cause certain impacts on local water resources. About 15 stock and domestic wells and 13 small stock reservoirs would be destroyed by mining. Shallow coal and sandstone aquifers would be permanently removed from parts of the tract. Leaching of soluble salts from mine spoils may cause a long-term degradation of the quality of water in shallow aquifers in or near the coal tract. Impacts on the local water resources could be mitigated by development of alternative ground-water supplies from deeper aquifers in the Fort Union and in the Upper Cretaceous Hell Creek and Fox Hills Formations. Reservoirs destroyed by mining could be reconstructed during mine reclamation. (USGS)

  3. Cold collisions of SH- with He: Potential energy surface and rate coefficients

    Science.gov (United States)

    Bop, C. T.; Trabelsi, T.; Hammami, K.; Mogren Al Mogren, M.; Lique, F.; Hochlaf, M.

    2017-09-01

    Collisional energy transfer under cold conditions is of great importance from the fundamental and applicative point of view. Here, we investigate low temperature collisions of the SH- anion with He. We have generated a three-dimensional potential energy surface (PES) for the SH-(X1Σ+)-He(1S) van der Waals complex. The ab initio multi-dimensional interaction PES was computed using the explicitly correlated coupled cluster approach with simple, double, and perturbative triple excitation in conjunction with the augmented-correlation consistent-polarized valence triple zeta Gaussian basis set. The PES presents two minima located at linear geometries. Then, the PES was averaged over the ground vibrational wave function of the SH- molecule and the resulting two-dimensional PES was incorporated into exact quantum mechanical close coupling calculations to study the collisional excitation of SH- by He. We have computed inelastic cross sections among the 11 first rotational levels of SH- for energies up to 2500 cm-1. (De-)excitation rate coefficients were deduced for temperatures ranging from 1 to 300 K by thermally averaging the cross sections. We also performed calculations using the new PES for a fixed internuclear SH- distance. Both sets of results were found to be in reasonable agreement despite differences existing at low temperatures confirming that accurate predictions require the consideration of all internal degrees of freedom in the case of molecular hydrides. The rate coefficients presented here may be useful in interpreting future experimental work on the SH- negative ion colliding with He as those recently done for the OH--He collisional system as well as for possible astrophysical applications in case SH- would be detected in the interstellar medium.

  4. Structure and stability of pyrophyllite edge surfaces: Effect of temperature and water chemical potential

    Science.gov (United States)

    Kwon, Kideok D.; Newton, Aric G.

    2016-10-01

    The surfaces of clay minerals, which are abundant in atmospheric mineral dust, serve as an important medium to catalyze ice nucleation. The lateral edge surface of 2:1 clay minerals is postulated to be a potential site for ice nucleation. However, experimental investigations of the edge surface structure itself have been limited compared to the basal planes of clay minerals. Density functional theory (DFT) computational studies have provided insights into the pyrophyllite edge surface. Pyrophyllite is an ideal surrogate mineral for the edge surfaces of 2:1 clay minerals as it possesses no or little structural charge. Of the two most-common hydrated edge surfaces, the AC edge, (1 1 0) surface in the monoclinic polytype notation, is predicted to be more stable than the B edge, (0 1 0) surface. These stabilities, however, were determined based on the total energies calculated at 0 K and did not consider environmental effects such as temperature and humidity. In this study, atomistic thermodynamics based on periodic DFT electronic calculations was applied to examine the effects of environmental variables on the structure and thermodynamic stability of the common edge surfaces in equilibrium with bulk pyrophyllite and water vapor. We demonstrate that the temperature-dependent vibrational energy of sorbed water molecules at the edge surface is a significant component of the surface free energy and cannot be neglected when determining the surface stability of pyrophyllite. The surface free energies were calculated as a function of temperature from 240 to 600 K and water chemical potential corresponding to conditions from ultrahigh vacuum to the saturation vapor pressure of water. We show that at lower water chemical potentials (dry conditions), the AC and B edge surfaces possessed similar stabilities; at higher chemical potentials (humid conditions) the AC edge surface was more stable than the B edge surface. At high temperatures, both surfaces showed similar stabilities