Polarizable embedding with a multiconfiguration short-range density functional theory linear response method

DEFF Research Database (Denmark)

Hedegård, Erik D.; Olsen, Jógvan Magnus Haugaard; Knecht, Stefan

2015-01-01

. To demonstrate the capabilities of PE-MC-srDFT, we also investigated the retinylidene Schiff base chromophore embedded in the channelrhodopsin protein. While using a much more compact reference wave function in terms of active space, our PE-MC-srDFT approach yields excitation energies comparable in quality......We present here the coupling of a polarizable embedding (PE) model to the recently developed multiconfiguration short-range density functional theory method (MC-srDFT), which can treat multiconfigurational systems with a simultaneous account for dynamical and static correlation effects. PE......-MC-srDFT is designed to combine efficient treatment of complicated electronic structures with inclusion of effects from the surrounding environment. The environmental effects encompass classical electrostatic interactions as well as polarization of both the quantum region and the environment. Using response theory...

The numerical multiconfiguration self-consistent field approach for atoms; Der numerische Multiconfiguration Self-Consistent Field-Ansatz fuer Atome

Energy Technology Data Exchange (ETDEWEB)

Stiehler, Johannes

1995-12-15

The dissertation uses the Multiconfiguration Self-Consistent Field Approach to specify the electronic wave function of N electron atoms in a static electrical field. It presents numerical approaches to describe the wave functions and introduces new methods to compute the numerical Fock equations. Based on results computed with an implemented computer program the universal application, flexibility and high numerical precision of the presented approach is shown. RHF results and for the first time MCSCF results for polarizabilities and hyperpolarizabilities of various states of the atoms He to Kr are discussed. In addition, an application to interpret a plasma spectrum of gallium is presented. (orig.)

Multi-configuration Dirac-Hartree-Fock (MCDHF) calculations for Ni XXV

Science.gov (United States)

Singh, Narendra; Aggarwal, Sunny

2018-03-01

We present accurate 165 fine-structure energy levels related to the configurations 1s22s2, 1s22p2, 1s2nƖn‧l‧ (n = 2, n‧ = 2, 3, 4, 5, Ɩ = s,p Ɩ‧ = s, p, d, f, g) of Ni XXV which may be useful ion for astrophysical and fusion plasma. For the calculations of energy levels and radiative rates, we have used the multiconfiguration Dirac-Hartree-Fock (MCDHF) method employed in GRASP2K code. The calculations are carried out in the active space approximation with the inclusion of the Breit interaction, the finite nuclear size effect, and quantum electrodynamic corrections. The transition wavelengths, transition probabilities, line strengths, and absorption oscillator strengths are reported for electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1), magnetic quadrupole (M2) transitions from the ground state. We have compared our calculated results with available theoretical and experimental data and good agreement is achieved. We predict new energy levels, oscillator strengths, line strengths and transition probabilities, where no other experimental or theoretical results are available. The present complete set of results should be of great help in line identification and the interpretation of spectra, as well as in the modelling and diagnostics of astrophysical and fusion plasmas.

Multiconfigurational self-consistent reaction field theory for nonequilibrium solvation

DEFF Research Database (Denmark)

Mikkelsen, Kurt V.; Cesar, Amary; Ågren, Hans

1995-01-01

electronic structure whereas the inertial polarization vector is not necessarily in equilibrium with the actual electronic structure. The electronic structure of the compound is described by a correlated electronic wave function - a multiconfigurational self-consistent field (MCSCF) wave function. This wave......, open-shell, excited, and transition states. We demonstrate the theory by computing solvatochromatic shifts in optical/UV spectra of some small molecules and electron ionization and electron detachment energies of the benzene molecule. It is shown that the dependency of the solvent induced affinity...

Decomposition of the configuration-interaction coefficients in the multiconfiguration time-dependent Hartree-Fock method

Energy Technology Data Exchange (ETDEWEB)

Lötstedt, Erik, E-mail: lotstedt@chem.s.u-tokyo.ac.jp; Kato, Tsuyoshi; Yamanouchi, Kaoru [Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

2016-04-21

An approximate implementation of the multiconfiguration time-dependent Hartree-Fock method is proposed, in which the matrix of configuration-interaction coefficients is decomposed into a product of matrices of smaller dimension. The applicability of this method in which all the configurations are kept in the expansion of the wave function, while the configuration-interaction coefficients are approximately calculated, is discussed by showing the results on three model systems: a one-dimensional model of a beryllium atom, a one-dimensional model of a carbon atom, and a one-dimensional model of a chain of four hydrogen atoms. The time-dependent electronic dynamics induced by a few-cycle, long-wavelength laser pulse is found to be well described at a lower computational cost compared to the standard multiconfiguration time-dependent Hartree-Fock treatment. Drawbacks of the method are also discussed.

Communication: An efficient approach to compute state-specific nuclear gradients for a generic state-averaged multi-configuration self consistent field wavefunction

Energy Technology Data Exchange (ETDEWEB)

Granovsky, Alexander A., E-mail: alex.granovsky@gmail.com [Firefly project, Moscow, 117593 Moscow (Russian Federation)

2015-12-21

We present a new, very efficient semi-numerical approach for the computation of state-specific nuclear gradients of a generic state-averaged multi-configuration self consistent field wavefunction. Our approach eliminates the costly coupled-perturbed multi-configuration Hartree-Fock step as well as the associated integral transformation stage. The details of the implementation within the Firefly quantum chemistry package are discussed and several sample applications are given. The new approach is routinely applicable to geometry optimization of molecular systems with 1000+ basis functions using a standalone multi-core workstation.

Communication: An efficient approach to compute state-specific nuclear gradients for a generic state-averaged multi-configuration self consistent field wavefunction

International Nuclear Information System (INIS)

Granovsky, Alexander A.

2015-01-01

We present a new, very efficient semi-numerical approach for the computation of state-specific nuclear gradients of a generic state-averaged multi-configuration self consistent field wavefunction. Our approach eliminates the costly coupled-perturbed multi-configuration Hartree-Fock step as well as the associated integral transformation stage. The details of the implementation within the Firefly quantum chemistry package are discussed and several sample applications are given. The new approach is routinely applicable to geometry optimization of molecular systems with 1000+ basis functions using a standalone multi-core workstation

Communication: An efficient approach to compute state-specific nuclear gradients for a generic state-averaged multi-configuration self consistent field wavefunction.

Science.gov (United States)

Granovsky, Alexander A

2015-12-21

We present a new, very efficient semi-numerical approach for the computation of state-specific nuclear gradients of a generic state-averaged multi-configuration self consistent field wavefunction. Our approach eliminates the costly coupled-perturbed multi-configuration Hartree-Fock step as well as the associated integral transformation stage. The details of the implementation within the Firefly quantum chemistry package are discussed and several sample applications are given. The new approach is routinely applicable to geometry optimization of molecular systems with 1000+ basis functions using a standalone multi-core workstation.

The numerical multiconfiguration self-consistent field approach for atoms

International Nuclear Information System (INIS)

Stiehler, Johannes

1995-12-01

The dissertation uses the Multiconfiguration Self-Consistent Field Approach to specify the electronic wave function of N electron atoms in a static electrical field. It presents numerical approaches to describe the wave functions and introduces new methods to compute the numerical Fock equations. Based on results computed with an implemented computer program the universal application, flexibility and high numerical precision of the presented approach is shown. RHF results and for the first time MCSCF results for polarizabilities and hyperpolarizabilities of various states of the atoms He to Kr are discussed. In addition, an application to interpret a plasma spectrum of gallium is presented. (orig.)

Multiconfiguration pair-density functional theory: barrier heights and main group and transition metal energetics.

Science.gov (United States)

Carlson, Rebecca K; Li Manni, Giovanni; Sonnenberger, Andrew L; Truhlar, Donald G; Gagliardi, Laura

2015-01-13

Kohn-Sham density functional theory, resting on the representation of the electronic density and kinetic energy by a single Slater determinant, has revolutionized chemistry, but for open-shell systems, the Kohn-Sham Slater determinant has the wrong symmetry properties as compared to an accurate wave function. We have recently proposed a theory, called multiconfiguration pair-density functional theory (MC-PDFT), in which the electronic kinetic energy and classical Coulomb energy are calculated from a multiconfiguration wave function with the correct symmetry properties, and the rest of the energy is calculated from a density functional, called the on-top density functional, that depends on the density and the on-top pair density calculated from this wave function. We also proposed a simple way to approximate the on-top density functional by translation of Kohn-Sham exchange-correlation functionals. The method is much less expensive than other post-SCF methods for calculating the dynamical correlation energy starting with a multiconfiguration self-consistent-field wave function as the reference wave function, and initial tests of the theory were quite encouraging. Here, we provide a broader test of the theory by applying it to bond energies of main-group molecules and transition metal complexes, barrier heights and reaction energies for diverse chemical reactions, proton affinities, and the water dimerization energy. Averaged over 56 data points, the mean unsigned error is 3.2 kcal/mol for MC-PDFT, as compared to 6.9 kcal/mol for Kohn-Sham theory with a comparable density functional. MC-PDFT is more accurate on average than complete active space second-order perturbation theory (CASPT2) for main-group small-molecule bond energies, alkyl bond dissociation energies, transition-metal-ligand bond energies, proton affinities, and the water dimerization energy.

Ground based measurements of particulate emissions from supersonic transports. Concorde olympus engine

Energy Technology Data Exchange (ETDEWEB)

Whitefield, Ph D; Hagen, D E [Missouri Univ., Rolla, MO (United States). Cloud and Aerosol Sciences Lab.; Lilenfeld, H V [McDonnell Douglas Corp., St. Louis, MO (United States)

1998-12-31

The application of a mobile aerosol monitoring facility, the Mobile Aerosol Sampling System (MASS) is described to characterize engine aerosol emissions from the Rolls Royce Olympus Engine. The multi-configurational MASS has been employed in both ground and airborne field operations. It has been successfully flown on research aircrafts. In ground tests the MASS has participated in numerous jet engine related ground tests, and has been deployed to resolve aerosol generation problems in a high power chemical laser system. In all cases the measurements were made on samples taken from a harsh physical and chemical environment, with both high and low temperature and pressure, and in the presence of highly reactive gases. (R.P.) 9 refs.

Ground based measurements of particulate emissions from supersonic transports. Concorde olympus engine

Energy Technology Data Exchange (ETDEWEB)

Whitefield, Ph.D.; Hagen, D.E. [Missouri Univ., Rolla, MO (United States). Cloud and Aerosol Sciences Lab.; Lilenfeld, H.V. [McDonnell Douglas Corp., St. Louis, MO (United States)

1997-12-31

The application of a mobile aerosol monitoring facility, the Mobile Aerosol Sampling System (MASS) is described to characterize engine aerosol emissions from the Rolls Royce Olympus Engine. The multi-configurational MASS has been employed in both ground and airborne field operations. It has been successfully flown on research aircrafts. In ground tests the MASS has participated in numerous jet engine related ground tests, and has been deployed to resolve aerosol generation problems in a high power chemical laser system. In all cases the measurements were made on samples taken from a harsh physical and chemical environment, with both high and low temperature and pressure, and in the presence of highly reactive gases. (R.P.) 9 refs.

Calculation of transition probabilities using the multiconfiguration Dirac-Fock method

International Nuclear Information System (INIS)

Kim, Yong Ki; Desclaux, Jean Paul; Indelicato, Paul

1998-01-01

The performance of the multiconfiguration Dirac-Fock (MCDF) method in calculating transition probabilities of atoms is reviewed. In general, the MCDF wave functions will lead to transition probabilities accurate to ∼ 10% or better for strong, electric-dipole allowed transitions for small atoms. However, it is more difficult to get reliable transition probabilities for weak transitions. Also, some MCDF wave functions for a specific J quantum number may not reduce to the appropriate L and S quantum numbers in the nonrelativistic limit. Transition probabilities calculated from such MCDF wave functions for nonrelativistically forbidden transitions are unreliable. Remedies for such cases are discussed

Multiconfigurational self-consistent field calculations of nuclear shieldings using London atomic orbitals

DEFF Research Database (Denmark)

Ruud, Kenneth; Helgaker, Trygve; Kobayashi, Rika

1994-01-01

to corresponding individual gauges for localized orbitals (IGLO) results. The London results show better basis set convergence than IGLO, especially for heavier atoms. It is shown that the choice of active space is crucial for determination of accurate nuclear shielding constants.......Nuclear shielding calculations are presented for multiconfigurational self-consistent field wave functions using London atomic orbitals (gauge invariant atomic orbitals). Calculations of nuclear shieldings for eight molecules (H2O, H2S, CH4, N2, CO, HF, F2, and SO2) are presented and compared...

A multiconfigurational time-dependent Hartree-Fock method for excited electronic states. I. General formalism and application to open-shell states.

Science.gov (United States)

Miranda, R P; Fisher, A J; Stella, L; Horsfield, A P

2011-06-28

The solution of the time-dependent Schrödinger equation for systems of interacting electrons is generally a prohibitive task, for which approximate methods are necessary. Popular approaches, such as the time-dependent Hartree-Fock (TDHF) approximation and time-dependent density functional theory (TDDFT), are essentially single-configurational schemes. TDHF is by construction incapable of fully accounting for the excited character of the electronic states involved in many physical processes of interest; TDDFT, although exact in principle, is limited by the currently available exchange-correlation functionals. On the other hand, multiconfigurational methods, such as the multiconfigurational time-dependent Hartree-Fock (MCTDHF) approach, provide an accurate description of the excited states and can be systematically improved. However, the computational cost becomes prohibitive as the number of degrees of freedom increases, and thus, at present, the MCTDHF method is only practical for few-electron systems. In this work, we propose an alternative approach which effectively establishes a compromise between efficiency and accuracy, by retaining the smallest possible number of configurations that catches the essential features of the electronic wavefunction. Based on a time-dependent variational principle, we derive the MCTDHF working equation for a multiconfigurational expansion with fixed coefficients and specialise to the case of general open-shell states, which are relevant for many physical processes of interest.

Multiconfiguration Pair-Density Functional Theory Is Free From Delocalization Error.

Science.gov (United States)

Bao, Junwei Lucas; Wang, Ying; He, Xiao; Gagliardi, Laura; Truhlar, Donald G

2017-11-16

Delocalization error has been singled out by Yang and co-workers as the dominant error in Kohn-Sham density functional theory (KS-DFT) with conventional approximate functionals. In this Letter, by computing the vertical first ionization energy for well separated He clusters, we show that multiconfiguration pair-density functional theory (MC-PDFT) is free from delocalization error. To put MC-PDFT in perspective, we also compare it with some Kohn-Sham density functionals, including both traditional and modern functionals. Whereas large delocalization errors are almost universal in KS-DFT (the only exception being the very recent corrected functionals of Yang and co-workers), delocalization error is removed by MC-PDFT, which bodes well for its future as a step forward from KS-DFT.

Molecular wave function and effective adiabatic potentials calculated by extended multi-configuration time-dependent Hartree-Fock method

Energy Technology Data Exchange (ETDEWEB)

Kato, Tsuyoshi; Ide, Yoshihiro; Yamanouchi, Kaoru [Department of Chemistry, School of Science, The University of Tokyo, 7-3-1, Hongo Bunkyo-ku, Tokyo, 113-0033 (Japan)

2015-12-31

We first calculate the ground-state molecular wave function of 1D model H{sub 2} molecule by solving the coupled equations of motion formulated in the extended multi-configuration time-dependent Hartree-Fock (MCTDHF) method by the imaginary time propagation. From the comparisons with the results obtained by the Born-Huang (BH) expansion method as well as with the exact wave function, we observe that the memory size required in the extended MCTDHF method is about two orders of magnitude smaller than in the BH expansion method to achieve the same accuracy for the total energy. Second, in order to provide a theoretical means to understand dynamical behavior of the wave function, we propose to define effective adiabatic potential functions and compare them with the conventional adiabatic electronic potentials, although the notion of the adiabatic potentials is not used in the extended MCTDHF approach. From the comparison, we conclude that by calculating the effective potentials we may be able to predict the energy differences among electronic states even for a time-dependent system, e.g., time-dependent excitation energies, which would be difficult to be estimated within the BH expansion approach.

Near-resonant absorption in the time-dependent self-consistent field and multiconfigurational self-consistent field approximations

DEFF Research Database (Denmark)

Norman, Patrick; Bishop, David M.; Jensen, Hans Jørgen Aa

2001-01-01

Computationally tractable expressions for the evaluation of the linear response function in the multiconfigurational self-consistent field approximation were derived and implemented. The finite lifetime of the electronically excited states was considered and the linear response function was shown...... to be convergent in the whole frequency region. This was achieved through the incorporation of phenomenological damping factors that lead to complex response function values....

Extended multi-configuration quasi-degenerate perturbation theory: the new approach to multi-state multi-reference perturbation theory.

Science.gov (United States)

Granovsky, Alexander A

2011-06-07

The distinctive desirable features, both mathematically and physically meaningful, for all partially contracted multi-state multi-reference perturbation theories (MS-MR-PT) are explicitly formulated. The original approach to MS-MR-PT theory, called extended multi-configuration quasi-degenerate perturbation theory (XMCQDPT), having most, if not all, of the desirable properties is introduced. The new method is applied at the second order of perturbation theory (XMCQDPT2) to the 1(1)A(')-2(1)A(') conical intersection in allene molecule, the avoided crossing in LiF molecule, and the 1(1)A(1) to 2(1)A(1) electronic transition in cis-1,3-butadiene. The new theory has several advantages compared to those of well-established approaches, such as second order multi-configuration quasi-degenerate perturbation theory and multi-state-second order complete active space perturbation theory. The analysis of the prevalent approaches to the MS-MR-PT theory performed within the framework of the XMCQDPT theory unveils the origin of their common inherent problems. We describe the efficient implementation strategy that makes XMCQDPT2 an especially useful general-purpose tool in the high-level modeling of small to large molecular systems. © 2011 American Institute of Physics

MATRIX (Multiconfiguration Aerosol TRacker of mIXing state): an aerosol microphysical module for global atmospheric models

OpenAIRE

Bauer , S. E.; Wright , D.; Koch , D.; Lewis , E. R.; Mcgraw , R.; Chang , L.-S.; Schwartz , S. E.; Ruedy , R.

2008-01-01

A new aerosol microphysical module MATRIX, the Multiconfiguration Aerosol TRacker of mIXing state, and its application in the Goddard Institute for Space Studies (GISS) climate model (ModelE) are described. This module, which is based on the quadrature method of moments (QMOM), represents nucleation, condensation, coagulation, internal and external mixing, and cloud-drop activation and provides aerosol particle mass and number concentration and particle size information for up to 16 mixed-mod...

Electronic symmetry breaking in polyatomic molecules. Multiconfiguration self-consistent field study of the cyclopropenyl radical C3H3

International Nuclear Information System (INIS)

Hoffmann, M.R.; Laidig, W.D.; Kim, K.S.; Fox, D.J.; Schaefer, H.F. III

1984-01-01

For equilateral triangle geometries (point group D/sub 3h/), the C 3 H 3 radical has a degenerate 2 E'' electronic ground state. Although the 2 A 2 and 2 B 1 components separate in energy for C/sub 2v/ geometries, these two components should have identical energies for equilateral triangle structures. In fact, when approximate wave functions are used and the orbitals not required to transform according to the D/sub 3h/ irreducible representations, an energy separation between the 2 A 2 and 2 B 1 components is observed. At the single configuration self-consistent field (SCF) level of theory this separation is 2.8 kcal with a double-zeta basis set and 2.4 kcal with double-zeta plus polarization. It has been demonstrated that this spurious separation may be greatly reduced using multiconfiguration self-consistent field (up to 7474 variationally optimum configurations) and configuration interaction (up to 60 685 space and spin adapted configurations) techniques. Configurations differing by three and four electrons from the Hartree--Fock reference function are found necessary to reduce the 2 A 2 - 2 B 1 separation to below 0.5 kcal

Investigation of electron-atom/molecule scattering resonances: Two complex multiconfigurational self-consistent field approaches

Energy Technology Data Exchange (ETDEWEB)

Samanta, Kousik [Department of Chemistry, Rice University, Houston, TX 77005 (United States); Yeager, Danny L. [Department of Chemistry, Texas A and M University, College Station, TX 77843 (United States)

2015-01-22

Resonances are temporarily bound states which lie in the continuum part of the Hamiltonian. If the electronic coordinates of the Hamiltonian are scaled (“dilated”) by a complex parameter, η = αe{sup iθ} (α, θ real), then its complex eigenvalues represent the scattering states (resonant and non-resonant) while the eigenvalues corresponding to the bound states and the ionization and the excitation thresholds remain real and unmodified. These make the study of these transient species amenable to the bound state methods. We developed a quadratically convergent multiconfigurational self-consistent field method (MCSCF), a well-established bound-state technique, combined with a dilated Hamiltonian to investigate resonances. This is made possible by the adoption of a second quantization algebra suitable for a set of “complex conjugate biorthonormal” spin orbitals and a modified step-length constraining algorithm to control the walk on the complex energy hypersurface while searching for the stationary point using a multidimensional Newton-Raphson scheme. We present our computational results for the {sup 2}PBe{sup −} shape resonances using two different computationally efficient methods that utilize complex scaled MCSCF (i.e., CMCSCF). These two methods are to straightforwardly use CMCSCF energy differences and to obtain energy differences using an approximation to the complex multiconfigurational electron propagator. It is found that, differing from previous computational studies by others, there are actually two {sup 2}PBe{sup −} shape resonances very close in energy. In addition, N{sub 2} resonances are examined using one of these methods.

Extension of the multiconfiguration Hartree-Fock program for continuum functions

International Nuclear Information System (INIS)

Fischer, C.F.; Saha, H.P.

1984-01-01

The wave function of an outer electron coupled to a core, possibly with correlation included in the core, is similar to a multiconfiguration Hartree-Fock (MCHF) wavefunction, except that the radial function of the electron is a continuum function, and different numerical procedures are required for determining it. Only a single continuum function is allowed, and the orbitals defining the wave function of the core and bound channels are assumed to be fixed. The coefficients in the expansion of the wave function of the core are also fixed and are the result of a bound state calculation for the core. Under these assumptions, the equation for the radial wave function of the electron is solved iteratively. The asymptotic phase shift is evaluated. In order to test the accuracy of the procedure, calculations were performed for the scattering of electrons by neutral hydrogen. Some results of a photo-ionization calculation are compared, and for an electron transition in nitrogen

On the universality of the long-/short-range separation in multiconfigurational density-functional theory. II. Investigating f⁰ actinide species

DEFF Research Database (Denmark)

Fromager, Emmanuel; Réal, Florent; Wåhlin, Pernilla

2009-01-01

In a previous paper [Fromager , J. Chem. Phys. 126, 074111 (2007)], some of the authors proposed a recipe for choosing the optimal value of the mu parameter that controls the long-range/short-range separation of the two-electron interaction in hybrid multiconfigurational self-consistent field sho...

Alternative separation of exchange and correlation energies in multi-configuration range-separated density-functional theory.

Science.gov (United States)

Stoyanova, Alexandrina; Teale, Andrew M; Toulouse, Julien; Helgaker, Trygve; Fromager, Emmanuel

2013-10-07

The alternative separation of exchange and correlation energies proposed by Toulouse et al. [Theor. Chem. Acc. 114, 305 (2005)] is explored in the context of multi-configuration range-separated density-functional theory. The new decomposition of the short-range exchange-correlation energy relies on the auxiliary long-range interacting wavefunction rather than the Kohn-Sham (KS) determinant. The advantage, relative to the traditional KS decomposition, is that the wavefunction part of the energy is now computed with the regular (fully interacting) Hamiltonian. One potential drawback is that, because of double counting, the wavefunction used to compute the energy cannot be obtained by minimizing the energy expression with respect to the wavefunction parameters. The problem is overcome by using short-range optimized effective potentials (OEPs). The resulting combination of OEP techniques with wavefunction theory has been investigated in this work, at the Hartree-Fock (HF) and multi-configuration self-consistent-field (MCSCF) levels. In the HF case, an analytical expression for the energy gradient has been derived and implemented. Calculations have been performed within the short-range local density approximation on H2, N2, Li2, and H2O. Significant improvements in binding energies are obtained with the new decomposition of the short-range energy. The importance of optimizing the short-range OEP at the MCSCF level when static correlation becomes significant has also been demonstrated for H2, using a finite-difference gradient. The implementation of the analytical gradient for MCSCF wavefunctions is currently in progress.

Multiconfiguration Dirac-Hartree-Fock calculations of energy levels and radiative rates of Fe VII

Science.gov (United States)

Li, Yang; Xu, Xiaokai; Li, Bowen; Jönsson, Per; Chen, Ximeng

2018-06-01

Detailed calculations are performed for 134 fine-structure levels of the 3p63d2, 3p63d4s, 3p53d3 and 3p63d4p configurations in Fe VII using the multiconfiguration Dirac-Hartree-Fock (MCDHF) and relativistic configuration interaction (RCI) methods. Important electron correlation effects are systematically accounted for through active space (AS) expansions. Our results compare well with experimental measurements, emphasizing the importance of a careful treatment of electron correlation, and provide some missing data in the NIST atomic database. The data obtained are expected to be useful in astrophysical applications, particularly for the research of the solar coronal plasma.

Procedures of grasp92 code to calculate accurate Dirac-Coulomb energy for the ground sate of helium atom

International Nuclear Information System (INIS)

Utsumi, Takayuki; Sasaki, Akira

2000-02-01

The procedures of grasp92 code to calculate accurate (relative error nearly equal 10 -7 ) eigenvalue for the ground sate of helium atom of the Dirac-Coulomb Hamiltonian are presented. The grasp92 code, based on the multi-configuration Dirac-Fock method, is widely used to calculate the atomic properties. However, the main part of the accurate calculations, extended optimal level calculation (EOL), suffer frequently numerical instabilities due to the lack of the confident procedures. The purpose of this report is to illustrate the guideline for stable EOL calculations by calculating the most fundamental atomic system, i.e. the ground sate of helium atom ls 2 1 S 2 . This procedure could be extended for the high-precise eigenfunction calculation of more complex atomic systems, for example highly ionized atoms and high-Z atoms. (author)

Generalized molecular orbital theory: a limited multiconfiguration self-consistent-field-theory

International Nuclear Information System (INIS)

Hall, M.B.

1981-01-01

The generalized molecular orbital (GMO) approach is a limited type of multiconfiguration self-consistent-field (MCSCF) calculation which divides the orbitals of a closed shell molecule into four shells: doubly occupied, strongly occupied, weakly occupied, and unoccupied. The orbitals within each shell have the same occupation number and are associated with the same Fock operator. Thus, the orbital optimization is ideally suited to solution via a coupling operator. The determination of the orbitals is followed by a configuration interaction (CI) calculation within the strongly and weakly occupied shells. Results for BH 3 show a striking similarity between the GMO's and the natural orbitals (NO's) from an all singles and doubles CI calculation. Although the GMO approach would not be accurate for an entire potential surface, results for spectroscopic constants of N 2 show that it is suitable near the equilibrium geometry. This paper describes the use of the GMO technique to determine the primary orbital space, but a potentially important application may be in the determination of a secondary orbital space following a more accurate MCSCF determination of the primary space

Computational Investigation of the Geometrical and Electronic Structures of VGen-/0 (n = 1-4) Clusters by Density Functional Theory and Multiconfigurational CASSCF/CASPT2 Method.

Science.gov (United States)

Tran, Van Tan; Nguyen, Minh Thao; Tran, Quoc Tri

2017-10-12

Density functional theory and the multiconfigurational CASSCF/CASPT2 method have been employed to study the low-lying states of VGe n -/0 (n = 1-4) clusters. For VGe -/0 and VGe 2 -/0 clusters, the relative energies and geometrical structures of the low-lying states are reported at the CASSCF/CASPT2 level. For the VGe 3 -/0 and VGe 4 -/0 clusters, the computational results show that due to the large contribution of the Hartree-Fock exact exchange, the hybrid B3LYP, B3PW91, and PBE0 functionals overestimate the energies of the high-spin states as compared to the pure GGA BP86 and PBE functionals and the CASPT2 method. On the basis of the pure GGA BP86 and PBE functionals and the CASSCF/CASPT2 results, the ground states of anionic and neutral clusters are defined, the relative energies of the excited states are computed, and the electron detachment energies of the anionic clusters are evaluated. The computational results are employed to give new assignments for all features in the photoelectron spectra of VGe 3 - and VGe 4 - clusters.

Selection of active spaces for multiconfigurational wavefunctions

Energy Technology Data Exchange (ETDEWEB)

Keller, Sebastian; Boguslawski, Katharina; Reiher, Markus, E-mail: markus.reiher@phys.chem.ethz.ch [Laboratorium für Physikalische Chemie, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich (Switzerland); Janowski, Tomasz; Pulay, Peter, E-mail: pulay@uark.edu [Department of Chemistry and Biochemistry, Fulbright College of Arts and Sciences, University of Arkansas, Fayetteville, Arkansas 72701 (United States)

2015-06-28

The efficient and accurate description of the electronic structure of strongly correlated systems is still a largely unsolved problem. The usual procedures start with a multiconfigurational (usually a Complete Active Space, CAS) wavefunction which accounts for static correlation and add dynamical correlation by perturbation theory, configuration interaction, or coupled cluster expansion. This procedure requires the correct selection of the active space. Intuitive methods are unreliable for complex systems. The inexpensive black-box unrestricted natural orbital (UNO) criterion postulates that the Unrestricted Hartree-Fock (UHF) charge natural orbitals with fractional occupancy (e.g., between 0.02 and 1.98) constitute the active space. UNOs generally approximate the CAS orbitals so well that the orbital optimization in CAS Self-Consistent Field (CASSCF) may be omitted, resulting in the inexpensive UNO-CAS method. A rigorous testing of the UNO criterion requires comparison with approximate full configuration interaction wavefunctions. This became feasible with the advent of Density Matrix Renormalization Group (DMRG) methods which can approximate highly correlated wavefunctions at affordable cost. We have compared active orbital occupancies in UNO-CAS and CASSCF calculations with DMRG in a number of strongly correlated molecules: compounds of electronegative atoms (F{sub 2}, ozone, and NO{sub 2}), polyenes, aromatic molecules (naphthalene, azulene, anthracene, and nitrobenzene), radicals (phenoxy and benzyl), diradicals (o-, m-, and p-benzyne), and transition metal compounds (nickel-acetylene and Cr{sub 2}). The UNO criterion works well in these cases. Other symmetry breaking solutions, with the possible exception of spatial symmetry, do not appear to be essential to generate the correct active space. In the case of multiple UHF solutions, the natural orbitals of the average UHF density should be used. The problems of the UNO criterion and their potential solutions

Selection of active spaces for multiconfigurational wavefunctions

International Nuclear Information System (INIS)

Keller, Sebastian; Boguslawski, Katharina; Reiher, Markus; Janowski, Tomasz; Pulay, Peter

2015-01-01

The efficient and accurate description of the electronic structure of strongly correlated systems is still a largely unsolved problem. The usual procedures start with a multiconfigurational (usually a Complete Active Space, CAS) wavefunction which accounts for static correlation and add dynamical correlation by perturbation theory, configuration interaction, or coupled cluster expansion. This procedure requires the correct selection of the active space. Intuitive methods are unreliable for complex systems. The inexpensive black-box unrestricted natural orbital (UNO) criterion postulates that the Unrestricted Hartree-Fock (UHF) charge natural orbitals with fractional occupancy (e.g., between 0.02 and 1.98) constitute the active space. UNOs generally approximate the CAS orbitals so well that the orbital optimization in CAS Self-Consistent Field (CASSCF) may be omitted, resulting in the inexpensive UNO-CAS method. A rigorous testing of the UNO criterion requires comparison with approximate full configuration interaction wavefunctions. This became feasible with the advent of Density Matrix Renormalization Group (DMRG) methods which can approximate highly correlated wavefunctions at affordable cost. We have compared active orbital occupancies in UNO-CAS and CASSCF calculations with DMRG in a number of strongly correlated molecules: compounds of electronegative atoms (F 2 , ozone, and NO 2 ), polyenes, aromatic molecules (naphthalene, azulene, anthracene, and nitrobenzene), radicals (phenoxy and benzyl), diradicals (o-, m-, and p-benzyne), and transition metal compounds (nickel-acetylene and Cr 2 ). The UNO criterion works well in these cases. Other symmetry breaking solutions, with the possible exception of spatial symmetry, do not appear to be essential to generate the correct active space. In the case of multiple UHF solutions, the natural orbitals of the average UHF density should be used. The problems of the UNO criterion and their potential solutions are discussed

Selection of active spaces for multiconfigurational wavefunctions

Science.gov (United States)

Keller, Sebastian; Boguslawski, Katharina; Janowski, Tomasz; Reiher, Markus; Pulay, Peter

2015-06-01

The efficient and accurate description of the electronic structure of strongly correlated systems is still a largely unsolved problem. The usual procedures start with a multiconfigurational (usually a Complete Active Space, CAS) wavefunction which accounts for static correlation and add dynamical correlation by perturbation theory, configuration interaction, or coupled cluster expansion. This procedure requires the correct selection of the active space. Intuitive methods are unreliable for complex systems. The inexpensive black-box unrestricted natural orbital (UNO) criterion postulates that the Unrestricted Hartree-Fock (UHF) charge natural orbitals with fractional occupancy (e.g., between 0.02 and 1.98) constitute the active space. UNOs generally approximate the CAS orbitals so well that the orbital optimization in CAS Self-Consistent Field (CASSCF) may be omitted, resulting in the inexpensive UNO-CAS method. A rigorous testing of the UNO criterion requires comparison with approximate full configuration interaction wavefunctions. This became feasible with the advent of Density Matrix Renormalization Group (DMRG) methods which can approximate highly correlated wavefunctions at affordable cost. We have compared active orbital occupancies in UNO-CAS and CASSCF calculations with DMRG in a number of strongly correlated molecules: compounds of electronegative atoms (F2, ozone, and NO2), polyenes, aromatic molecules (naphthalene, azulene, anthracene, and nitrobenzene), radicals (phenoxy and benzyl), diradicals (o-, m-, and p-benzyne), and transition metal compounds (nickel-acetylene and Cr2). The UNO criterion works well in these cases. Other symmetry breaking solutions, with the possible exception of spatial symmetry, do not appear to be essential to generate the correct active space. In the case of multiple UHF solutions, the natural orbitals of the average UHF density should be used. The problems of the UNO criterion and their potential solutions are discussed

Generalized Møller-Plesset Multiconfiguration Perturbation Theory Applied to an Open-Shell Antisymmetric Product of Strongly Orthogonal Geminals Reference Wave Function.

Science.gov (United States)

Tarumi, Moto; Kobayashi, Masato; Nakai, Hiromi

2012-11-13

The antisymmetric product of strongly orthogonal geminals (APSG) method is a wave function theory that can effectively treat the static electron correlation. Recently, we proposed the open-shell APSG method using one-electron orbitals for open-shell parts. In this paper, we have extended the perturbation correction to the open-shell APSG calculations through Møller-Plesset-type multiconfiguration perturbation theory (MP-MCPT). Numerical applications demonstrate that the present open-shell MP-MCPT can reasonably reproduce the dissociation energies or equilibrium distances for open-shell systems.

New homo- and heteroleptic derivatives of trivalent ytterbium containing anion-radical 1,4-diazadiene ligands. Synthesis, properties and crystal structure of (C9H7)2Yb[2-MeC6H4NC(Me)C(Me)NC6H4Me-2] and [PhNC(Ph)C(Ph)NPh]3Yb complexes

International Nuclear Information System (INIS)

Gudilenkov, I.D.; Fukin, G.K.; Cherkasov, A.V.; Shavyrin, A.S.; Trifonov, A.A.; Larionova, Yu.E.

2008-01-01

Reaction of ytterbium bisindenyl complex (C 9 H 7 ) 2 Yb II (THF) 2 (1) with 1,4-diazabutadiene 2-MeC 6 H 4 N=C(Me)-C(Me)=NC 6 H 4 Me-2 ( Me DAD) is accompanied by the oxidation of metal atom until trivalent state and results in the formation of paramagnetic compound of metallocenes type (C 9 H 7 ) 2 Yb III ( Me DAD -. ) (3) containing 1,4-diazabutadiene anion-radical. Structure of complex 3 is ascertained by the X-ray structure analysis. Reactions of bisindenyl (1) and bisfluorenyl (C 13 H 9 ) 2 Yb II (THF) 2 (2) derivatives of bivalent ytterbium with 1,4-diazabutadiene PhN=C(Ph)-C(Ph)=NPh ( Ph DAD) (at 1:2 molar ratio of reagents) proceed with the complete break of Yb-C bonds, oxidation of ytterbium atom until trivalent state, and result in the formation of homoligand complex ( Ph DAD -. ) 3 Yb (6) containing three anion-radical 1,4-diazadiene ligands. Complex 6 was also prepared by the exchange reaction of YbCl 3 with Ph DAD -. K + (1:3) in THF. Complex 6 is characterized by the X-ray structure analysis [ru

Multiconfiguration time-dependent self-consistent field approximations in the numerical solution of quantum dynamical problems

International Nuclear Information System (INIS)

Kotler, Z.; Neria, E.; Nitzan, A.

1991-01-01

The use of the time-dependent self-consistent field approximation (TDSCF) in the numerical solution of quantum curve crossing and tunneling dynamical problems is investigated. Particular emphasis is given to multiconfiguration TDSCF (MCTDSCF) approximations, which are shown to perform considerably better with only a small increase in computational effort. We investigate a number of simple models in which a 'system' characterized by two electronic potential surfaces evolves while interacting with a 'bath' mode described by an harmonic oscillator, and compare exact numerical solutions to one- and two-configuration TDSCF approximations. We also introduce and investigate a semiclassical approximation in which the 'bath' mode is described by semiclassical wavepackets (one for each electronic state) and show that for all models investigated this scheme works very well in comparison with the fully quantum MCTDSCF approximation. This provides a potentially very useful method to simulate strongly quantum systems coupled to an essentially classical environment. (orig.)

Multiconfiguration time-dependent self-consistent field approximations in the numerical solution of quantum dynamical problems

Energy Technology Data Exchange (ETDEWEB)

Kotler, Z.; Neria, E.; Nitzan, A. (Tel Aviv Univ. (Israel). School of Chemistry)

1991-02-01

The use of the time-dependent self-consistent field approximation (TDSCF) in the numerical solution of quantum curve crossing and tunneling dynamical problems is investigated. Particular emphasis is given to multiconfiguration TDSCF (MCTDSCF) approximations, which are shown to perform considerably better with only a small increase in computational effort. We investigate a number of simple models in which a 'system' characterized by two electronic potential surfaces evolves while interacting with a 'bath' mode described by an harmonic oscillator, and compare exact numerical solutions to one- and two-configuration TDSCF approximations. We also introduce and investigate a semiclassical approximation in which the 'bath' mode is described by semiclassical wavepackets (one for each electronic state) and show that for all models investigated this scheme works very well in comparison with the fully quantum MCTDSCF approximation. This provides a potentially very useful method to simulate strongly quantum systems coupled to an essentially classical environment. (orig.).

Use of Large-Scale Multi-Configuration EMI Measurements to Characterize Subsurface Structures of the Vadose Zone.

Science.gov (United States)

Huisman, J. A.; Brogi, C.; Pätzold, S.; Weihermueller, L.; von Hebel, C.; Van Der Kruk, J.; Vereecken, H.

2017-12-01

Subsurface structures of the vadose zone can play a key role in crop yield potential, especially during water stress periods. Geophysical techniques like electromagnetic induction EMI can provide information about dominant shallow subsurface features. However, previous studies with EMI have typically not reached beyond the field scale. We used high-resolution large-scale multi-configuration EMI measurements to characterize patterns of soil structural organization (layering and texture) and their impact on crop productivity at the km2 scale. We collected EMI data on an agricultural area of 1 km2 (102 ha) near Selhausen (NRW, Germany). The area consists of 51 agricultural fields cropped in rotation. Therefore, measurements were collected between April and December 2016, preferably within few days after the harvest. EMI data were automatically filtered, temperature corrected, and interpolated onto a common grid of 1 m resolution. Inspecting the ECa maps, we identified three main sub-areas with different subsurface heterogeneity. We also identified small-scale geomorphological structures as well as anthropogenic activities such as soil management and buried drainage networks. To identify areas with similar subsurface structures, we applied image classification techniques. We fused ECa maps obtained with different coil distances in a multiband image and applied supervised and unsupervised classification methodologies. Both showed good results in reconstructing observed patterns in plant productivity and the subsurface structures associated with them. However, the supervised methodology proved more efficient in classifying the whole study area. In a second step, we selected hundred locations within the study area and obtained a soil profile description with type, depth, and thickness of the soil horizons. Using this ground truth data it was possible to assign a typical soil profile to each of the main classes obtained from the classification. The proposed methodology was

Molcas 8: New capabilities for multiconfigurational quantum chemical calculations across the periodic table.

Science.gov (United States)

Aquilante, Francesco; Autschbach, Jochen; Carlson, Rebecca K; Chibotaru, Liviu F; Delcey, Mickaël G; De Vico, Luca; Fdez Galván, Ignacio; Ferré, Nicolas; Frutos, Luis Manuel; Gagliardi, Laura; Garavelli, Marco; Giussani, Angelo; Hoyer, Chad E; Li Manni, Giovanni; Lischka, Hans; Ma, Dongxia; Malmqvist, Per Åke; Müller, Thomas; Nenov, Artur; Olivucci, Massimo; Pedersen, Thomas Bondo; Peng, Daoling; Plasser, Felix; Pritchard, Ben; Reiher, Markus; Rivalta, Ivan; Schapiro, Igor; Segarra-Martí, Javier; Stenrup, Michael; Truhlar, Donald G; Ungur, Liviu; Valentini, Alessio; Vancoillie, Steven; Veryazov, Valera; Vysotskiy, Victor P; Weingart, Oliver; Zapata, Felipe; Lindh, Roland

2016-02-15

In this report, we summarize and describe the recent unique updates and additions to the Molcas quantum chemistry program suite as contained in release version 8. These updates include natural and spin orbitals for studies of magnetic properties, local and linear scaling methods for the Douglas-Kroll-Hess transformation, the generalized active space concept in MCSCF methods, a combination of multiconfigurational wave functions with density functional theory in the MC-PDFT method, additional methods for computation of magnetic properties, methods for diabatization, analytical gradients of state average complete active space SCF in association with density fitting, methods for constrained fragment optimization, large-scale parallel multireference configuration interaction including analytic gradients via the interface to the Columbus package, and approximations of the CASPT2 method to be used for computations of large systems. In addition, the report includes the description of a computational machinery for nonlinear optical spectroscopy through an interface to the QM/MM package Cobramm. Further, a module to run molecular dynamics simulations is added, two surface hopping algorithms are included to enable nonadiabatic calculations, and the DQ method for diabatization is added. Finally, we report on the subject of improvements with respects to alternative file options and parallelization. © 2015 Wiley Periodicals, Inc.

Single-photon double ionization: renormalized-natural-orbital theory versus multi-configurational Hartree–Fock

International Nuclear Information System (INIS)

Brics, M; Rapp, J; Bauer, D

2017-01-01

The N -particle wavefunction has too many dimensions for a direct time propagation of a many-body system according to the time-dependent Schrödinger equation (TDSE). On the other hand, time-dependent density functional theory (TDDFT) tells us that the single-particle density is, in principle, sufficient. However, a practicable equation of motion for the accurate time evolution of the single-particle density is unknown. It is thus an obvious idea to propagate a quantity which is not as reduced as the single-particle density but less dimensional than the N -body wavefunction. Recently, we have introduced time-dependent renormalized-natural-orbital theory (TDRNOT). TDRNOT is based on the propagation of the eigenfunctions of the one-body reduced density matrix, the so-called natural orbitals. In this paper we demonstrate how TDRNOT is related to the multi-configurational time-dependent Hartree–Fock (MCTDHF) approach. We also compare the performance of MCTDHF and TDRNOT versus the TDSE for single-photon double ionization (SPDI) of a 1D helium model atom. SPDI is one of the effects where TDDFT does not work in practice, especially if one is interested in correlated photoelectron spectra, for which no explicit density functional is known. (paper)

Intermediate-Valence Tautomerism in Decamethylytterbocene Complexes of Methyl-Substituted Bipyridines

Energy Technology Data Exchange (ETDEWEB)

Booth, Corwin H.; Kazhdan, Daniel; Werkema, Evan L.; Walter, Marc D.; Lukens, Wayne W.; Bauer, Eric D.; Hu, Yung-Jin; Maron, Laurent; Eisenstein, Odile; Head-Gordon, Martin; Andersen, Richard A.

2011-01-25

Multiconfigurational, intermediate valent ground states are established in several methyl-substituted bipyridine complexes of bispentamethylcyclopentadienylytterbium, Cp*{sub 2} Yb(Me{sub x}-bipy). In contrast to Cp*{sub 2} Yb(bipy) and other substituted-bipy complexes, the nature of both the ground state and the first excited state are altered by changing the position of the methyl or dimethyl substitutions on the bipyridine rings. In particular, certain substitutions result in multiconfigurational, intermediate valent open-shell singlet states in both the ground state and the first excited state. These conclusions are reached after consideration of single-crystal x-ray diffraction (XRD), the temperature dependence of x-ray absorption near-edge structure (XANES), extended x-ray absorption fine-structure (EXAFS), and magnetic susceptibility data, and are supported by CASSCF-MP2 calculations. These results place the various Cp*{sub 2}Yb(bipy) complexes in a new tautomeric class, that is, intermediate-valence tautomers.

MCSCF wave functions for excited states of polar molecules - Application to BeO. [Multi-Configuration Self-Consistent Field

Science.gov (United States)

Bauschlicher, C. W., Jr.; Yarkony, D. R.

1980-01-01

A previously reported multi-configuration self-consistent field (MCSCF) algorithm based on the generalized Brillouin theorem is extended in order to treat the excited states of polar molecules. In particular, the algorithm takes into account the proper treatment of nonorthogonality in the space of single excitations and invokes, when necessary, a constrained optimization procedure to prevent the variational collapse of excited states. In addition, a configuration selection scheme (suitable for use in conjunction with extended configuration interaction methods) is proposed for the MCSCF procedure. The algorithm is used to study the low-lying singlet states of BeO, a system which has not previously been studied using an MCSCF procedure. MCSCF wave functions are obtained for three 1 Sigma + and two 1 Pi states. The 1 Sigma + results are juxtaposed with comparable results for MgO in order to assess the generality of the description presented here.

Effect of high lying states on the ground and few low lying excited O+ energy levels of some closed-shell nuclei

International Nuclear Information System (INIS)

Ayoub, N.Y.

1980-02-01

The ground and some excited O + (J=O, T=O positive parity) energy levels of closed-shell nuclei are examined, in an oscillator basis, using matrix techniques. The effect of states outside the mixed (O+2(h/2π)ω). model space in 4 He (namely configurations at 4(h/2π)ω excitation) are taken into account by renormalization using the generalized Rayleigh-Schroedinger perturbation expressions for a mixed multi-configurational model space, where the resultant non-symmetric energy matrices are diagonalized. It is shown that the second-order renormalized O + energy spectrum is close to the corresponding energy spectrum obtained by diagonalizing the O+2+4(h/2π)ω 4 He energy matrix. The effect, on the ground state and the first few low-lying excited O + energy levels, of renormalizing certain parts of the model space energy matrix up to second order in various approximations is also studied in 4 He and 16 O. It is found that the low-lying O + energy levels in these various approximations behave similarly in both 4 He and 16 O. (author)

Non-equilibrium quantum dynamics of ultra-cold atomic mixtures: the multi-layer multi-configuration time-dependent Hartree method for bosons

International Nuclear Information System (INIS)

Krönke, Sven; Cao, Lushuai; Schmelcher, Peter; Vendrell, Oriol

2013-01-01

We develop and apply the multi-layer multi-configuration time-dependent Hartree method for bosons, which represents an ab initio method for investigating the non-equilibrium quantum dynamics of multi-species bosonic systems. Its multi-layer feature allows for tailoring the wave function ansatz to describe intra- and inter-species correlations accurately and efficiently. To demonstrate the beneficial scaling and efficiency of the method, we explored the correlated tunneling dynamics of two species with repulsive intra- and inter-species interactions, to which a third species with vanishing intra-species interaction was weakly coupled. The population imbalances of the first two species can feature a temporal equilibration and their time evolution significantly depends on the coupling to the third species. Bosons of the first and second species exhibit a bunching tendency, whose strength can be influenced by their coupling to the third species. (paper)

Detection of Multiconfigurational States of Hydrogen-Passivated Silicene Nanoclusters.

Science.gov (United States)

Pablo-Pedro, Ricardo; Lopez-Rios, Hector; Fomine, Serguei; Dresselhaus, Mildred S

2017-02-02

Utilizing density functional theory (DFT) and a complete active space self-consistent field (CASSCF) approach,we study the electronic properties of rectangular silicene nano clusters with hydrogen passivated edges denoted by H-SiNCs (n z ,n a ), with n z and n a representing the zigzag and armchair directions, respectively. The results show that in the n z direction, the H-SiNCs prefer to be in a singlet (S = 0) ground state for n z > n a . However, a transition from a singlet (S = 0) to a triplet (S = 1) ground state is revealed for n a > n z . Through the calculated Raman spectrum, the S = 0 and S = 1 ground states can be observed by the E 2g (G) and A (D) Raman modes. Furthermore, H-SiNC clusters are shown to have HOMO-LUMO (HL) energy gaps, which decrease as a function of n a and n z for S = 0 and S = 1 states. The H-SiNC with a S = 1 ground state can be potentially used for silicene-based spintronic devices.

Detection of Multiconfigurational States of Hydrogen-Passivated Silicene Nanoclusters

KAUST Repository

Pablo-Pedro, Ricardo; Lopez-Rios, Hector; Fomine, Serguei; Dresselhaus, Mildred S.

2017-01-01

Utilizing density functional theory (DFT) and a complete active space self-consistent field (CASSCF) approach,we study the electronic properties of rectangular silicene nano clusters with hydrogen passivated edges denoted by H-SiNCs (nz,na), with nz and na representing the zigzag and armchair directions, respectively. The results show that in the nz direction, the H-SiNCs prefer to be in a singlet (S = 0) ground state for nz > na. However, a transition from a singlet (S = 0) to a triplet (S = 1) ground state is revealed for na > nz. Through the calculated Raman spectrum, the S = 0 and S = 1 ground states can be observed by the E2g (G) and A (D) Raman modes. Furthermore, H-SiNC clusters are shown to have HOMO–LUMO (HL) energy gaps, which decrease as a function of na and nz for S = 0 and S = 1 states. The H-SiNC with a S = 1 ground state can be potentially used for silicene-based spintronic devices.

Detection of Multiconfigurational States of Hydrogen-Passivated Silicene Nanoclusters

KAUST Repository

Pablo-Pedro, Ricardo

2017-01-16

Utilizing density functional theory (DFT) and a complete active space self-consistent field (CASSCF) approach,we study the electronic properties of rectangular silicene nano clusters with hydrogen passivated edges denoted by H-SiNCs (nz,na), with nz and na representing the zigzag and armchair directions, respectively. The results show that in the nz direction, the H-SiNCs prefer to be in a singlet (S = 0) ground state for nz > na. However, a transition from a singlet (S = 0) to a triplet (S = 1) ground state is revealed for na > nz. Through the calculated Raman spectrum, the S = 0 and S = 1 ground states can be observed by the E2g (G) and A (D) Raman modes. Furthermore, H-SiNC clusters are shown to have HOMO–LUMO (HL) energy gaps, which decrease as a function of na and nz for S = 0 and S = 1 states. The H-SiNC with a S = 1 ground state can be potentially used for silicene-based spintronic devices.

Use of large-scale multi-configuration EMI measurements to characterize heterogeneous subsurface structures and their impact on crop productivity

Science.gov (United States)

Brogi, Cosimo; Huisman, Johan Alexander; Kaufmann, Manuela Sarah; von Hebel, Christian; van der Kruk, Jan; Vereecken, Harry

2017-04-01

Soil subsurface structures can play a key role in crop performance, especially during water stress periods. Geophysical techniques like electromagnetic induction EMI have been shown to be able of providing information about dominant shallow subsurface features. However, previous work with EMI has typically not reached beyond the field scale. The objective of this study is to use large-scale multi-configuration EMI to characterize patterns of soil structural organization (layering and texture) and the associated impact on crop vegetation at the km2 scale. For this, we carried out an intensive measurement campaign and collected high spatial resolution multi-configuration EMI data on an agricultural area of approx. 1 km2 (102 ha) near Selhausen (North Rhine-Westphalia, Germany) with a maximum depth of investigation of around 2.5 m. We measured using two EMI instruments simultaneously with a total of nine coil configurations. The instruments were placed inside polyethylene sleds that were pulled by an all-terrain-vehicle along parallel lines with a spacing of 2 to 2.5 m. The driving speed was between 5 and 7 km h-1 and we used a 0.2 Hz sampling frequency to obtain an in-line resolution of approximately 0.3 m. The survey area consists of almost 50 different fields managed in different way. The EMI measurements were collected between April and December 2016 within a few days after the harvest of each field. After data acquisition, EMI data were automatically filtered, temperature corrected, and interpolated onto a common grid. The resulting EMI maps allowed us to identify three main areas with different subsurface heterogeneities. The differences between these areas are likely related to the late quaternary geological history (Pleistocene and Holocene) of the area that resulted in spatially variable soil texture and layering, which has a strong impact on spatio-temporal soil water content variability. The high resolution surveys also allowed us to identify small scale

Using a pruned, nondirect product basis in conjunction with the multi-configuration time-dependent Hartree (MCTDH) method

Energy Technology Data Exchange (ETDEWEB)

Wodraszka, Robert, E-mail: Robert.Wodraszka@chem.queensu.ca; Carrington, Tucker, E-mail: Tucker.Carrington@queensu.ca [Department of Chemistry, Queen’s University, Kingston, Ontario K7L 3N6 (Canada)

2016-07-28

In this paper, we propose a pruned, nondirect product multi-configuration time dependent Hartree (MCTDH) method for solving the Schrödinger equation. MCTDH uses optimized 1D basis functions, called single particle functions, but the size of the standard direct product MCTDH basis scales exponentially with D, the number of coordinates. We compare the pruned approach to standard MCTDH calculations for basis sizes small enough that the latter are possible and demonstrate that pruning the basis reduces the CPU cost of computing vibrational energy levels of acetonitrile (D = 12) by more than two orders of magnitude. Using the pruned method, it is possible to do calculations with larger bases, for which the cost of standard MCTDH calculations is prohibitive. Pruning the basis complicates the evaluation of matrix-vector products. In this paper, they are done term by term for a sum-of-products Hamiltonian. When no attempt is made to exploit the fact that matrices representing some of the factors of a term are identity matrices, one needs only to carefully constrain indices. In this paper, we develop new ideas that make it possible to further reduce the CPU time by exploiting identity matrices.

Designing a capacitated multi-configuration logistics network under disturbances and parameter uncertainty: a real-world case of a drug supply chain

Science.gov (United States)

Shishebori, Davood; Babadi, Abolghasem Yousefi

2018-03-01

This study investigates the reliable multi-configuration capacitated logistics network design problem (RMCLNDP) under system disturbances, which relates to locating facilities, establishing transportation links, and also allocating their limited capacities to the customers conducive to provide their demand on the minimum expected total cost (including locating costs, link constructing costs, and also expected costs in normal and disturbance conditions). In addition, two types of risks are considered; (I) uncertain environment, (II) system disturbances. A two-level mathematical model is proposed for formulating of the mentioned problem. Also, because of the uncertain parameters of the model, an efficacious possibilistic robust optimization approach is utilized. To evaluate the model, a drug supply chain design (SCN) is studied. Finally, an extensive sensitivity analysis was done on the critical parameters. The obtained results show that the efficiency of the proposed approach is suitable and is worthwhile for analyzing the real practical problems.

Geological characterization of contaminated sites in urban areas (Denmark)

DEFF Research Database (Denmark)

Andersen, Theis Raaschou; Nissen, Randi Warncke; Poulsen, Søren Erbs

to increase the density of the field data, the two areas were mapped using combined Electrical Resistivity Tomography (ERT) and Induced Polarization (IP), and a multi-configuration Ground Conductivity Meter (DualEM421). Based on the borehole information and the high-density geophysical data, detailed 3D...

A homologous series of homoleptic zinc bis(1,4-di-tert-butyl-1,4-diaza-1,3-butadiene) complexes: Kx[Zn(t-BuNCHCHN-t-Bu)2], Zn(t-BuNCHCHN-t-Bu)2, and [Zn(t-BuNCHCHN-t-Bu)2](OTf)x)(X=1,2)

NARCIS (Netherlands)

Koten, G. van; Rijnberg, E.; Richter, B.; Thiele, K.-H.; Boersma, J.; Veldman, N.; Spek, A.L.

1998-01-01

A homologous series of mono- and dicationic, neutral, and mono- and dianionic zinc diazabutadiene complexes, Kx[Zn(t-BuNCHCHN-t-Bu)2], Zn(t-BuNCHCHN-t-Bu)2, and [Zn(t-BuNCHCHN-t-Bu)2](OTf)x (x = 1, 2), have been prepared and isolated in pure form. The crystal structures of the mono- and dicationic

Alternative Synthesis of 2,4-Substituted-1,3-thiazines and 2,5 ...

African Journals Online (AJOL)

To the best of our knowledge, this is the first report in which phenacetamidines have been utilized as precursors for thiazine synthesis. The syntheses of novel cyclic fused 1,3-diazabutadienes 13 and 2-aza-1,3-butadiene 17, and iodocyclization of 17 leading to the formation of thiazole 16a are also reported. In this paper a ...

MCSCF optimization through combined use of natural orbitals and the Brillouin-Levy-Berthier theorem

International Nuclear Information System (INIS)

Ruedenberg, K.; Cheung, L.M.; Elbert, S.T.

1979-01-01

A novel approach is developed for optimizing molecular orbitals within the context of a multiconfiguration self-consistent-field problem. The MCSCF wave function is determined through a sequence of eigenvalue problems in the multiconfiguration space and the single-excitation space. They are used iteratively to improve the natural orbitals, which in turn are related, by successively improved transformations, to the MCSCF orbitals. The mathematical problems arising out of this general concept are solved and the computational implementation is discussed. In many applications the method has proven itself as a powerful approach in forcing rapid convergence. Adaptation to spin and spatial symmetry is maintained throughout, and the procedure is applicable to excited states as well as to ground states. 3 figures, 2 tables

On the universality of the long-/short-range separation in multiconfigurational density-functional theory

Science.gov (United States)

Fromager, Emmanuel; Toulouse, Julien; Jensen, Hans Jørgen Aa.

2007-02-01

In many cases, the dynamic correlation can be calculated quite accurately and at a fairly low computational cost in Kohn-Sham density-functional theory (KS-DFT), using current standard approximate functionals. However, in general, KS-DFT does not treat static correlation effects (near degeneracy) adequately which, on the other hand, can be described in wave-function theory (WFT), for example, with a multiconfigurational self-consistent field (MCSCF) model. It is therefore of high interest to develop a hybrid model which combines the best of both WFT and DFT approaches. The merge of WFT and DFT can be achieved by splitting the two-electron interaction into long-range and short-range parts. The long-range part is then treated by WFT and the short-range part by DFT. In this work the authors consider the so-called "erf" long-range interaction erf(μr12)/r12, which is based on the standard error function, and where μ is a free parameter which controls the range of the long-/short-range decomposition. In order to formulate a general method, they propose a recipe for the definition of an optimal μopt parameter, which is independent of the approximate short-range functional and the approximate wave function, and they discuss its universality. Calculations on a test set consisting of He, Be, Ne, Mg, H2, N2, and H2O yield μopt≈0.4a.u.. A similar analysis on other types of test systems such as actinide compounds is currently in progress. Using the value of 0.4a.u. for μ, encouraging results are obtained with the hybrid MCSCF-DFT method for the dissociation energies of H2, N2, and H2O, with both short-range local-density approximation and PBE-type functionals.

Adding Theoretical Grounding to Grounded Theory: Toward Multi-Grounded Theory

OpenAIRE

Göran Goldkuhl; Stefan Cronholm

2010-01-01

The purpose of this paper is to challenge some of the cornerstones of the grounded theory approach and propose an extended and alternative approach for data analysis and theory development, which the authors call multi-grounded theory (MGT). A multi-grounded theory is not only empirically grounded; it is also grounded in other ways. Three different grounding processes are acknowledged: theoretical, empirical, and internal grounding. The authors go beyond the pure inductivist approach in GT an...

A full-dimensional multilayer multiconfiguration time-dependent Hartree study on the ultraviolet absorption spectrum of formaldehyde oxide

International Nuclear Information System (INIS)

Meng, Qingyong; Meyer, Hans-Dieter

2014-01-01

Employing the multilayer multiconfiguration time-dependent Hartree (ML-MCTDH) method in conjunction with the multistate multimode vibronic coupling Hamiltonian (MMVCH) model, we perform a full dimensional (9D) quantum dynamical study on the simplest Criegee intermediate, formaldehyde oxide, in five lower-lying singlet electronic states. The ultraviolet (UV) spectrum is then simulated by a Fourier transform of the auto-correlation function. The MMVCH model is built based on extensive MRCI(8e,8o)/aug-cc-pVTZ calculations. To ensure a fast convergence of the final calculations, a large number of ML-MCTDH test calculations is performed to find an appropriate multilayer separations (ML-trees) of the ML-MCTDH nuclear wave functions, and the dynamical calculations are carefully checked to ensure that the calculations are well converged. To compare the computational efficiency, standard MCTDH simulations using the same Hamiltonian are also performed. A comparison of the MCTDH and ML-MCTDH calculations shows that even for the present not-too-large system (9D here) the ML-MCTDH calculations can save a considerable amount of computational resources while producing identical spectra as the MCTDH calculations. Furthermore, the present theoretical B ~ 1 A ′ ←X ~ 1 A ′ UV spectral band and the corresponding experimental measurements [J. M. Beames, F. Liu, L. Lu, and M. I. Lester, J. Am. Chem. Soc. 134, 20045–20048 (2012); L. Sheps, J. Phys. Chem. Lett. 4, 4201–4205 (2013); W.-L. Ting, Y.-H. Chen, W. Chao, M. C. Smith, and J. J.-M. Lin, Phys. Chem. Chem. Phys. 16, 10438–10443 (2014)] are discussed. To the best of our knowledge, this is the first theoretical UV spectrum simulated for this molecule including nuclear motion beyond an adiabatic harmonic approximation

Systematic theoretical investigation of the zero-field splitting in Gd(III) complexes: Wave function and density functional approaches

Energy Technology Data Exchange (ETDEWEB)

Khan, Shehryar, E-mail: sherkhan@fysik.su.se; Odelius, Michael, E-mail: odelius@fysik.su.se [Department of Physics, Stockholm University, AlbaNova University Center, S-106 91 Stockholm (Sweden); Kubica-Misztal, Aleksandra [Institute of Physics, Jagiellonian University, ul. Reymonta 4, PL-30-059 Krakow (Poland); Kruk, Danuta [Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, Sloneczna 54, Olsztyn PL-10710 (Poland); Kowalewski, Jozef [Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm (Sweden)

2015-01-21

The zero-field splitting (ZFS) of the electronic ground state in paramagnetic ions is a sensitive probe of the variations in the electronic and molecular structure with an impact on fields ranging from fundamental physical chemistry to medical applications. A detailed analysis of the ZFS in a series of symmetric Gd(III) complexes is presented in order to establish the applicability and accuracy of computational methods using multiconfigurational complete-active-space self-consistent field wave functions and of density functional theory calculations. The various computational schemes are then applied to larger complexes Gd(III)DOTA(H{sub 2}O){sup −}, Gd(III)DTPA(H{sub 2}O){sup 2−}, and Gd(III)(H{sub 2}O){sub 8}{sup 3+} in order to analyze how the theoretical results compare to experimentally derived parameters. In contrast to approximations based on density functional theory, the multiconfigurational methods produce results for the ZFS of Gd(III) complexes on the correct order of magnitude.

MATRIX (Multiconfiguration Aerosol TRacker of mIXing state: an aerosol microphysical module for global atmospheric models

Directory of Open Access Journals (Sweden)

S. E. Bauer

2008-10-01

Full Text Available A new aerosol microphysical module MATRIX, the Multiconfiguration Aerosol TRacker of mIXing state, and its application in the Goddard Institute for Space Studies (GISS climate model (ModelE are described. This module, which is based on the quadrature method of moments (QMOM, represents nucleation, condensation, coagulation, internal and external mixing, and cloud-drop activation and provides aerosol particle mass and number concentration and particle size information for up to 16 mixed-mode aerosol populations. Internal and external mixing among aerosol components sulfate, nitrate, ammonium, carbonaceous aerosols, dust and sea-salt particles are represented. The solubility of each aerosol population, which is explicitly calculated based on its soluble and insoluble components, enables calculation of the dependence of cloud drop activation on the microphysical characterization of multiple soluble aerosol populations.

A detailed model description and results of box-model simulations of various aerosol population configurations are presented. The box model experiments demonstrate the dependence of cloud activating aerosol number concentration on the aerosol population configuration; comparisons to sectional models are quite favorable. MATRIX is incorporated into the GISS climate model and simulations are carried out primarily to assess its performance/efficiency for global-scale atmospheric model application. Simulation results were compared with aircraft and station measurements of aerosol mass and number concentration and particle size to assess the ability of the new method to yield data suitable for such comparison. The model accurately captures the observed size distributions in the Aitken and accumulation modes up to particle diameter 1 μm, in which sulfate, nitrate, black and organic carbon are predominantly located; however the model underestimates coarse-mode number concentration and size, especially in the marine environment

4,6-Dibromo-N-{3-[(4,6-dibromo-2,3-dimethylphenylimino]butan-2-ylidene}-2,3-dimethylaniline

Directory of Open Access Journals (Sweden)

Lina Huang

2013-10-01

Full Text Available The title compound, C20H20Br4N2, is a product of the condensation reaction of 4,6-dibromo-2,3-dimethylaniline and butane-2,3-dione. The molecule has a center of symmetry at the mid-point of the central C—C bond. The dihedral angle between the benzene ring and the 1,4-diazabutadiene plane is 78.3 (2°. Niether hydrogen bonding nor aromatic stacking is observed in the crystal structure.

Energy-level scheme and transition probabilities of Si-like ions

International Nuclear Information System (INIS)

Huang, K.N.

1984-01-01

Theoretical energy levels and transition probabilities are presented for 27 low-lying levels of silicon-like ions from Z = 15 to Z = 106. The multiconfiguration Dirac-Fock technique is used to calculate energy levels and wave functions. The Breit interaction and Lamb shift contributions are calculated perturbatively as corrections to the Dirac-Fock energy. The M1 and E2 transitions between the first nine levels and the E1 transitions between excited and the ground levels are presented

Noncollinear Spin States for Density Functional Calculations of Open-Shell and Multi-Configurational Systems: Dissociation of MnO and NiO and Barrier Heights of O3, BeH2, and H4.

Science.gov (United States)

Luo, Sijie; Truhlar, Donald G

2013-12-10

When the spins of molecular orbitals are allowed to be aligned with different directions in space rather than being aligned collinearly, the resulting noncollinear spin orbitals add extra flexibility to variational optimization of the orbitals, and solutions obtained with collinear spin orbitals may be unstable with respect to becoming noncollinear in the expanded variational space. The goal of the present work is to explore whether and in what way the molecular orbitals of the Kohn-Sham density functional theory become noncollinear when fully optimized for multi-reference molecules, transition states, and reaction paths. (We note that a noncollinear determinant has intermediate flexibility between a collinear determinant and a linear combination of many collinear determinants with completely independent coefficients. However, the Kohn-Sham method is defined to involve the variational optimization of a single determinant, and a noncollinear determinant represents the limit of complete optimization in the Kohn-Sham scheme.) We compare the results obtained with the noncollinear Kohn-Sham (NKS) scheme to those obtained with the widely used unrestricted Kohn-Sham (UKS) scheme for two types of multi-reference systems. For the dissociation of the MnO and NiO transition metal oxides, we find UKS fails to dissociate to the ground states of neutral atoms, while NKS dissociates to the correct limit and predicts potential energy curves that vary smoothly at intermediate bond lengths. This is due to the instability of UKS solutions at large bond distances. For barrier heights of O3, BeH2, and H4, NKS is shown to stabilize the multi-reference transition states by expanding the variational space. Although the errors vary because they are closely coupled with the capability of the employed exchange-correlation functionals in treating the multi-configurational states, these findings demonstrate that results with collinear spin orbitals should be further scrutinized, and future

TFTR grounding scheme and ground-monitor system

International Nuclear Information System (INIS)

Viola, M.

1983-01-01

The Tokamak Fusion Test Reactor (TFTR) grounding system utilizes a single-point ground. It is located directly under the machine, at the basement floor level, and is tied to the building perimeter ground. Wired to this single-point ground, via individual 500 MCM insulated cables, are: the vacuum vessel; four toroidal field coil cases/inner support structure quadrants; umbrella structure halves; the substructure ring girder; radial beams and columns; and the diagnostic systems. Prior to the first machine operation, a ground-loop removal program was initiated. It required insulation of all hangers and supports (within a 35-foot radius of the center of the machine) of the various piping, conduits, cable trays, and ventilation systems. A special ground-monitor system was designed and installed. It actively monitors each of the individual machine grounds to insure that there are no inadvertent ground loops within the machine structure or its ground and that the machine grounds are intact prior to each pulse. The TFTR grounding system has proven to be a very manageable system and one that is easy to maintain

Quantum chemical studies on electronic structure and photodynamics of ruthenium complexes

International Nuclear Information System (INIS)

Freitag, L.

2015-01-01

Ruthenium complexes have found their way into many applications in the last decades. Among those, ruthenium polypyridyl compounds have been employed as light harvesting devices and photosensitisers in artificial photosynthesis and molecular photocatalysis. Ruthenium nitrosyl complexes are rapidly emerging as NO delivery agents to biological tissues with promising applications in anticancer photodynamic therapy, thanks to their ability to photorelease nitric oxide (NO). This thesis encompasses computational studies on reactivity, electronic structure, excited states and photodynamics of several ruthenium nitrosyl and polypyridyl complexes. The first part of the thesis deals with ruthenium nitrosyls. The cis-trans isomerisation mechanism of RuHIndNO, a ruthenium nitrosyl derivate of the prominent anti-cancer drug candidate KP1019, is investigated with density functional theory calculations. Next, the electronic structure of the ground and the first excited triplet state of RuHIndNO is studied with multiconfigurational methods including the density-matrix renormalisation group (DMRG). The obtained multiconfigurational wavefunctions and DMRG-based orbital entanglement analysis provides theoretical insight into the non-innocence of the NO ligand in nitrosyl complexes by describing the electron correlation in the Ru--NO bond and assigning oxidation states to the metal and the NO ligand. Another study is performed on excited states of ruthenium nitrosyl complexes with quantum chemical calculations and surface-hopping dynamics to obtain insights into the photodissociation mechanism of NO. The second part of this thesis is devoted to the excited states and photophysics of ruthenium polypyridyl complexes. Accurate excitation energies of tris(2,2-bipyridine)ruthenium (II), the prototype ruthenium polypyridyl are obtained with multiconfigurational calculations assisted by an orbital entanglement analysis. Subsequently, the effect of the ligand substitution on the photophysics

Geophysical mapping of the subsurface to support climate adaption in development areas

DEFF Research Database (Denmark)

Andersen, Theis Raaschou

ha is high-densely mapped with multi-configuration Ground Conductivity Meter (DualEM421) and supplemented with Airborne Electro Magnetic surveys, Electrical Resistivity Tomography (ERT) and boreholes. The depth of investigation for the DUALEM421 system is between 5 to 8 m and the horizontal...... correlation between the deposits’ electric resistivity and the infiltration capabilities. Based on the soil types’ different infiltration capabilities, it will be possible to produce a detailed infiltration potential map for the development areas. The project is conducted in collaboration with Horsens...

Communication grounding facility

International Nuclear Information System (INIS)

Lee, Gye Seong

1998-06-01

It is about communication grounding facility, which is made up twelve chapters. It includes general grounding with purpose, materials thermal insulating material, construction of grounding, super strength grounding method, grounding facility with grounding way and building of insulating, switched grounding with No. 1A and LCR, grounding facility of transmission line, wireless facility grounding, grounding facility in wireless base station, grounding of power facility, grounding low-tenton interior power wire, communication facility of railroad, install of arrester in apartment and house, install of arrester on introduction and earth conductivity and measurement with introduction and grounding resistance.

Multiconfigurational and DFT analyses of the electromeric formulation and UV-vis absorption spectra of the superoxide adduct of ferrous superoxide reductase.

Science.gov (United States)

Attia, Amr A A; Cioloboc, Daniela; Lupan, Alexandru; Silaghi-Dumitrescu, Radu

2016-12-01

The putative initial adduct of ferrous superoxide reductase (SOR) with superoxide has been alternatively formulated as ferric-peroxo or ferrous-superoxo. The ~600-nm UV-vis absorption band proposed to be assigned to this adduct (either as sole intermediate in the SOR catalytic cycle, or as one of the two intermediates) has recently been interpreted as due to a ligand-to-metal charge transfer, involving thiolate and superoxide in a ferrous complex, contrary to an alternative assignment as a predominantly cysteine thiolate-to-ferric charge transfer in a ferric-peroxo electromer. In an attempt to clarify the electromeric formulation of this adduct, we report a computational study using a multiconfigurational complete active space self-consistent field (MC-CASSCF) wave function approach as well as modelling the UV-vis absorption spectra with time-dependent density functional theory (TD-DFT). The MC-CASSCF calculations disclose a weak interaction between iron and the dioxygenic ligand and a dominant configuration with an essentially ferrous-superoxo character. The computed UV-vis absorption spectra reveal a marked dependence on the choice of density functional - both in terms of location of bands and in terms of orbital contributors. For the main band in the visible region, besides the recently reported thiolate-to-superoxide charge transfer, a more salient, and less functional-dependent, feature is a thiolate-to-ferric iron charge transfer, consistent with a ferric-peroxo electromer. By contrast, the computed UV-vis spectra of a ferric-hydroperoxo SOR model match distinctly better (and with no qualitative dependence on the DFT methodology) the 600-nm band as due to a mainly thiolate-to-ferric character - supporting the assignment of the SOR "600-nm intermediate" as a S=5/2 ferric-hydroperoxo species. Copyright © 2016 Elsevier Inc. All rights reserved.

Ground Pollution Science

International Nuclear Information System (INIS)

Oh, Jong Min; Bae, Jae Geun

1997-08-01

This book deals with ground pollution science and soil science, classification of soil and fundamentals, ground pollution and human, ground pollution and organic matter, ground pollution and city environment, environmental problems of the earth and ground pollution, soil pollution and development of geological features of the ground, ground pollution and landfill of waste, case of measurement of ground pollution.

Interpretation of the photoelectron spectra of FeS(2)(-) by a multiconfiguration computational approach.

Science.gov (United States)

Clima, Sergiu; Hendrickx, Marc F A

2007-11-01

The ground states of FeS(2) and FeS(2)(-), and several low-lying excited electronic states of FeS(2) that are responsible for the FeS(2)(-) photoelectron spectrum, are calculated. At the B3LYP level an open, quasi-linear [SFeS](-) conformation is found as the most stable structure, which is confirmed at the ab initio CASPT2 computational level. Both the neutral and the anionic unsaturated complexes possess high-spin electronic ground states. For the first time a complete assignment of the photoelectron spectrum of FeS(2)(-) is proposed. The lowest energy band in this spectrum is ascribed to an electron detachment from the two highest-lying 3dpi antibonding orbitals (with respect to the iron-sulfur bonding) of iron. The next-lowest experimental band corresponds to an electron removal from nonbonding, nearly pure sulfur orbitals. The two highest bands in the spectra are assigned as electron detachments from pi and sigma bonding mainly sulfur orbitals.

2,3-Bis[(3-methylbiphenyl-4-ylimino]butane

Directory of Open Access Journals (Sweden)

Jingjing Chen

2014-04-01

Full Text Available The title compound, C30H28N2, is a product of the condensation reaction of 2-methyl-4-phenylaniline and butane-2,3-dione. The molecule lies on a crystallographic inversion centre. The C=N bond has an E conformation. The dihedral angle between the two benzene rings of the 4-phenyl-2-methylphenyl group is 29.19 (76°. The 1,4-diazabutadiene plane makes an angle of 70.1 (10° with the N-bonded methylphenyl ring and an angle of 81.08 (97° with the terminal phenyl group.

Grounded theory.

Science.gov (United States)

Harris, Tina

2015-04-29

Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.

Ground cross-modal impedance as a tool for analyzing ground/plate interaction and ground wave propagation.

Science.gov (United States)

Grau, L; Laulagnet, B

2015-05-01

An analytical approach is investigated to model ground-plate interaction based on modal decomposition and the two-dimensional Fourier transform. A finite rectangular plate subjected to flexural vibration is coupled with the ground and modeled with the Kirchhoff hypothesis. A Navier equation represents the stratified ground, assumed infinite in the x- and y-directions and free at the top surface. To obtain an analytical solution, modal decomposition is applied to the structure and a Fourier Transform is applied to the ground. The result is a new tool for analyzing ground-plate interaction to resolve this problem: ground cross-modal impedance. It allows quantifying the added-stiffness, added-mass, and added-damping from the ground to the structure. Similarity with the parallel acoustic problem is highlighted. A comparison between the theory and the experiment shows good matching. Finally, specific cases are investigated, notably the influence of layer depth on plate vibration.

Competition-strength-dependent ground suppression in figure-ground perception.

Science.gov (United States)

Salvagio, Elizabeth; Cacciamani, Laura; Peterson, Mary A

2012-07-01

Figure-ground segregation is modeled as inhibitory competition between objects that might be perceived on opposite sides of borders. The winner is the figure; the loser is suppressed, and its location is perceived as shapeless ground. Evidence of ground suppression would support inhibitory competition models and would contribute to explaining why grounds are shapeless near borders shared with figures, yet such evidence is scarce. We manipulated whether competition from potential objects on the ground side of figures was high (i.e., portions of familiar objects were potentially present there) or low (novel objects were potentially present). We predicted that greater competition would produce more ground suppression. The results of two experiments in which suppression was assessed via judgments of the orientation of target bars confirmed this prediction; a third experiment showed that ground suppression is short-lived. Our findings support inhibitory competition models of figure assignment, in particular, and models of visual perception entailing feedback, in general.

Regional analysis of ground and above-ground climate

Science.gov (United States)

1981-12-01

The regional suitability of underground construction as a climate control technique is discussed with reference to (1) a bioclimatic analysis of long term weather data for 29 locations in the United States to determine appropriate above ground climate control techniques, (2) a data base of synthesized ground temperatures for the coterminous United States, and (3) monthly dew point ground temperature comparisons for identifying the relative likelihood of condensation from one region to another. It is concluded that the suitability of Earth tempering as a practice and of specific Earth sheltered design stereotypes varies geographically; while the subsurface almost always provides a thermal advantage on its own terms when compared to above ground climatic data, it can, nonetheless, compromise the effectiveness of other, regionally more important climate control techniques. Reviews of above and below ground climate mapping schemes related to human comfort and architectural design, and detailed description of a theoretical model of ground temperature, heat flow, and heat storage in the ground are included. Strategies of passive climate control are presented in a discussion of the building bioclimatic analysis procedure which has been applied in a computer analysis of 30 years of weather data for each of 20 locations in the United States.

Regional analysis of ground and above-ground climate

Energy Technology Data Exchange (ETDEWEB)

1981-12-01

The regional suitability of underground construction as a climate control technique is discussed with reference to (1) a bioclimatic analysis of long-term weather data for 29 locations in the United States to determine appropriate above ground climate control techniques, (2) a data base of synthesized ground temperatures for the coterminous United States, and (3) monthly dew point ground temperature comparisons for identifying the relative likelihood of condensation from one region to another. It is concluded that the suitability of earth tempering as a practice and of specific earth-sheltered design stereotypes varies geographically; while the subsurface almost always provides a thermal advantage on its own terms when compared to above ground climatic data, it can, nonetheless, compromise the effectiveness of other, regionally more important climate control techniques. Also contained in the report are reviews of above and below ground climate mapping schemes related to human comfort and architectural design, and detailed description of a theoretical model of ground temperature, heat flow, and heat storage in the ground. Strategies of passive climate control are presented in a discussion of the building bioclimatic analysis procedure which has been applied in a computer analysis of 30 years of weather data for each of 29 locations in the United States.

Relativistic calculations of the fine-structure intervals of the ns2np2P terms and the ionization energies of the Ca-, Sr-and Ba- ions

International Nuclear Information System (INIS)

Wijesundera, W.P.; Vosko, S.H.; Parpia, F.A.

1996-01-01

We report new calculations of the energy differences between the ns 1/2 2 np 1/2 and ns 1/2 2 np 3/2 levels of the Ca - , Sr - and Ba - ions; here n 4, 5 and 6 for Ca - , Sr - and Ba - , respectively. The electron affinities of Ca, Ba and Sr have also been calculated. All estimates were obtained by performing a series of multiconfiguration Dirac-Fock calculations for the neutral atoms and their anions. Correlations among valence electrons in both the ground and excited states were included in these calculations. Our estimate of the fine structure of the ground state of Sr - is in good agreement with recent measurements. Our estimates of the electron affinities of Ca, Sr and Ba are in reasonable agreement with experiment. (author)

Fine Structure Intervals ‎ ‎-‎ ‎ , ‎ ‎-‎ ‎ and ‎Electric Dipole Transition Rate ‎ ‎-‎ ‎ in ‎Phosphorus Isoelectronic Sequence ‎ ‎ ‎And Phosphorus Ions

Directory of Open Access Journals (Sweden)

Adnan Yousif Hussein

2017-11-01

Full Text Available A systematic study for the calculation of the fine structure intervals -  and -   for the ground configuration 3s23p3 and the excited configuration 3s23p24s respectively, and electric dipole transition rate -  as well as transition energy form the excited configuration 3s23p24s to the ground configuration 3s23p3 in Phosphorus isoelectronic sequence by applying multi-configuration Dirac-Fock (MCDF method. The effect of Breit interaction, QED and correlation on the fine structure interval and the gauge invariance effect on the transition probability are studied. Also the fine structure intervals for the phosphorus ions from Piii to Pxv are calculated and are compared with the available experimental data and gives good consistent

Ground water '89

International Nuclear Information System (INIS)

1989-01-01

The proceedings of the 5th biennial symposium of the Ground Water Division of the Geological Society of South Africa are presented. The theme of the symposium was ground water and mining. Papers were presented on the following topics: ground water resources; ground water contamination; chemical analyses of ground water and mining and its influece on ground water. Separate abstracts were prepared for 5 of the papers presented. The remaining papers were considered outside the subject scope of INIS

Density matrix renormalization group with efficient dynamical electron correlation through range separation

DEFF Research Database (Denmark)

Hedegård, Erik D.; Knecht, Stefan; Kielberg, Jesper Skau

2015-01-01

We present a new hybrid multiconfigurational method based on the concept of range-separation that combines the density matrix renormalization group approach with density functional theory. This new method is designed for the simultaneous description of dynamical and static electroncorrelation...... effects in multiconfigurational electronic structure problems....

Traditional behaviour and fidelity to caribou calving grounds by barren-ground caribou

Directory of Open Access Journals (Sweden)

Anne Gunn

1986-06-01

Full Text Available Evidence for the fidelity of female barren-ground caribou (Rangifer tarandus spp. of each herd to specific calving grounds is convincing. Involvement of learned behaviour in the annual return of those cows to the same calving grounds implies such actions are a form of «traditional» behaviour. Even wide variations in population size have not yet knowingly led to marked changes in size or location of calving grounds or prolonged abandonment of established ones. Rarely is the adoption of new calving grounds reported and emigration to another herd's calving ground or interchange between calving grounds has not yet been unequivocally documented. The calving experience of individual caribou and environmental pressures may modify the cow's use patterns of her calving grounds. The current definition of herds based on traditional calving grounds may require modification, if increasing caribou numbers result in changes in traditions. However, current data do not contradict either the fidelity to traditional calving grounds or the concept of herd identity based on that fidelity.

GROUNDED THEORY METHODOLOGY and GROUNDED THEORY RESEARCH in TURKEY

OpenAIRE

ARIK, Ferhat; ARIK, Işıl Avşar

2016-01-01

This research discusses the historical development of the Grounded Theory Methodology, which is one of the qualitative research method, its transformation over time and how it is used as a methodology in Turkey. The Grounded Theory which was founded by Strauss and Glaser, is a qualitative methodology based on inductive logic to discover theories in contrast with the deductive understanding which is based on testing an existing theory in sociology. It is possible to examine the Grounded Theory...

Grounding-Induced Sectional Forces and Residual Strength of Grounded Ship Hulls

DEFF Research Database (Denmark)

Paik, Jeom Kee; Pedersen, Preben Terndrup

1996-01-01

The aim of the present study is to determine the sectional forces induced by ship grounding and also to assess the residual strength of groundedship hulls. An analytical approach is used to estimate the grounding-induced sectional forces of ships. The extent and location of structural damage due...... to grounding is defined based on the ABS Safe Hull guide. The residual strength of damaged hulls is calculated by using a simple analytical formula. The method is applied to residual strength assessment of a damaged double hull tanker of 38,400 dwt due to grounding....

Constructivist Grounded Theory?

Directory of Open Access Journals (Sweden)

Barney G. Glaser, PhD, Hon. PhD

2012-06-01

Full Text Available AbstractI refer to and use as scholarly inspiration Charmaz’s excellent article on constructivist grounded theory as a tool of getting to the fundamental issues on why grounded theory is not constructivist. I show that constructivist data, if it exists at all, is a very, very small part of the data that grounded theory uses.

Ground water and energy

Energy Technology Data Exchange (ETDEWEB)

1980-11-01

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

Rigour and grounded theory.

Science.gov (United States)

Cooney, Adeline

2011-01-01

This paper explores ways to enhance and demonstrate rigour in a grounded theory study. Grounded theory is sometimes criticised for a lack of rigour. Beck (1993) identified credibility, auditability and fittingness as the main standards of rigour for qualitative research methods. These criteria were evaluated for applicability to a Straussian grounded theory study and expanded or refocused where necessary. The author uses a Straussian grounded theory study (Cooney, In press) to examine how the revised criteria can be applied when conducting a grounded theory study. Strauss and Corbin (1998b) criteria for judging the adequacy of a grounded theory were examined in the context of the wider literature examining rigour in qualitative research studies in general and grounded theory studies in particular. A literature search for 'rigour' and 'grounded theory' was carried out to support this analysis. Criteria are suggested for enhancing and demonstrating the rigour of a Straussian grounded theory study. These include: cross-checking emerging concepts against participants' meanings, asking experts if the theory 'fit' their experiences, and recording detailed memos outlining all analytical and sampling decisions. IMPLICATIONS FOR RESEARCH PRACTICE: The criteria identified have been expressed as questions to enable novice researchers to audit the extent to which they are demonstrating rigour when writing up their studies. However, it should not be forgotten that rigour is built into the grounded theory method through the inductive-deductive cycle of theory generation. Care in applying the grounded theory methodology correctly is the single most important factor in ensuring rigour.

Dipropyl 3,6-diphenyl-1,2-dihydro-1,2,4,5-tetrazine-1,2-dicarboxylate.

Science.gov (United States)

Rao, Guo-Wu; Hu, Wei-Xiao

2003-05-01

The title compound, C(22)H(24)N(4)O(4), was prepared from propyl chloroformate and 3,6-diphenyl-1,2-dihydro-s-tetrazine. This reaction yields the title compound rather than dipropyl 3,6-diphenyl-1,4-dihydro-s-tetrazine-1,4-dicarboxylate. The 2,3-diazabutadiene group in the central six-membered ring is not planar; the C=N double-bond length is 1.285 (2) A, and the average N-N single-bond length is 1.401 (3) A, indicating a lack of conjugation. The ring has a twist conformation, in which adjacent N atoms lie +/- 0.3268 (17) A from the plane of the ring. The molecule has twofold crystallographic symmetry.

Grounding of SNS Accelerator Structure

CERN Document Server

Holik, Paul S

2005-01-01

Description of site general grounding network. RF grounding network enhancement underneath the klystron gallery building. Grounding network of the Ring Systems with ground breaks in the Ring Tunnel. Grounding and Bonding of R&D accelerator equipment. SNS Building lightning protection.

Jung's equation of the ground of being with the ground of psyche.

Science.gov (United States)

Dourley, John

2011-09-01

The paper amplifies Jung's psychology of ground associated with the culmination of the alchemical process in the unus mundus. It argues that Jung and Dorn identify the experience of the ground with the experience of divinity as the common originary source of individual and totality. It notes the monistic and pantheistic implications of the experience and goes on to amplify the experience through Eckhart's mediaeval mysticism of ground and Paul Tillich's modern philosophical/theological understanding of ground. It concludes that the Jung/Dorn psychological understanding of ground supersedes monotheistic consciousness. Their vision supports the emergence of a societal myth based on the identification of the ground as the source of all divinities and faith in them. This source currently urges a mythic consciousness that would surpass its past and current concretions and so alleviate the threat that monotheistic consciousness in any domain now poses to human survival. © 2011, The Society of Analytical Psychology.

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

Science.gov (United States)

Moran, Edward H.; Galloway, Devin L.

2006-01-01

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

Computational Approaches to the Determination of the Molecular Geometry of Acrolein in its T_1(n,π*) State

Science.gov (United States)

McAnally, Michael O.; Hlavacek, Nikolaus C.; Drucker, Stephen

2012-06-01

The spectroscopically derived inertial constants for acrolein (propenal) in its T_1(n,π*) state were used to test predictions from a variety of computational methods. One focus was on multiconfigurational methods, such as CASSCF and CASPT2, that are applicable to excited states. We also examined excited-state methods that utilize single reference configurations, including EOM-EE-CCSD and TD-PBE0. Finally, we applied unrestricted ground-state techniques, such as UCCSD(T) and the more economical UPBE0 method, to the T_1(n,π*) excited state under the constraint of C_s symmetry. The unrestricted ground-state methods are applicable because at a planar geometry, the T_1(n,π*) state of acrolein is the lowest-energy state of its spin multiplicity. Each of the above methods was used with a triple zeta quality basis set to optimize the T_1(n,π*) geometry. This procedure resulted in the following sets of inertial constants: Inertial constants (cm-1) of acrolein in its T_1(n,π*) state Method A B C Method A B C CASPT2(6,5) 1.667 0.1491 0.1368 UCCSD(T)^b 1.668 0.1480 0.1360 CASSCF(6,5) 1.667 0.1491 0.1369 UPBE0 1.699 0.1487 0.1367 EOM-EE-CCSD 1.675 0.1507 0.1383 TD-PBE0 1.719 0.1493 0.1374 Experiment^a 1.662 0.1485 0.1363 The two multiconfigurational methods produce the same inertial constants, and those constants agree closely with experiment. However the sets of computed bond lengths differ significantly for the two methods. In the CASSCF calculation, the lengthening of the C=O and C=C bonds and the shortening of the C--C bond are more pronounced than in CASPT2. O. S. Bokareva et al., Int. J. Quant. Chem. {108}, 2719 (2008).

[Introduction to grounded theory].

Science.gov (United States)

Wang, Shou-Yu; Windsor, Carol; Yates, Patsy

2012-02-01

Grounded theory, first developed by Glaser and Strauss in the 1960s, was introduced into nursing education as a distinct research methodology in the 1970s. The theory is grounded in a critique of the dominant contemporary approach to social inquiry, which imposed "enduring" theoretical propositions onto study data. Rather than starting from a set theoretical framework, grounded theory relies on researchers distinguishing meaningful constructs from generated data and then identifying an appropriate theory. Grounded theory is thus particularly useful in investigating complex issues and behaviours not previously addressed and concepts and relationships in particular populations or places that are still undeveloped or weakly connected. Grounded theory data analysis processes include open, axial and selective coding levels. The purpose of this article was to explore the grounded theory research process and provide an initial understanding of this methodology.

The 5s25p2 - (5s25p5d + 5s5p3 + 5s25p6s + 5s25p7s) transitions in Sb II and 5s25p - (5s5p2 + 5s2nl) transitions in Sb III

International Nuclear Information System (INIS)

Arcimowicz, B.; Joshi, Y.N.; Kaufman, V.

1989-01-01

The spectrum of antimony was photographed in the 575-2300 A region (1A 10 -10 m) using a hollow cathode and a triggered spark source. The analysis of the 5s 2 5p 2 - (5s 2 5p5d + 5s5p 3 + 5s 2 5p6s + 5s 2 5p7s) transitions in Sb II spectrum was revised and interpreted on the basis of multiconfiguration interaction calculations. Accurate wavelength measurements of Sb III lines lead to a revised ground-state 5s 2 5p 2 P interval value of 6574.5 cm -1 . (author). 15 refs., 9 tabs., 1 fig

Construction of a quartz spherical analyzer: application to high-resolution analysis of the Ni Kα emission spectrum

International Nuclear Information System (INIS)

Honnicke, Marcelo Goncalves; Cusatis, Cesar

2016-01-01

The construction and characterization of a focusing X-ray spherical analyzer based on α-quartz 44̄04 are presented. For this study, the performance of the analyzer was demonstrated by applying it to a high-resolution X-ray spectroscopy study of theKα_1_,_2emission spectrum of Ni. An analytical representation based on physical grounds was assumed to model the shape of the X-ray emission lines. Satellite structures assigned to 3dspectator hole transitions were resolved and determined as well as their relative contribution to the emission spectrum. The present results on 1s"-"13d"-"1shake probabilities support a recently proposed calculation framework based on a multi-configuration atomic model.

The Grounded Theory Bookshelf

Directory of Open Access Journals (Sweden)

Dr. Alvita Nathaniel, DSN, APRN, BC

2005-06-01

Full Text Available The Grounded Theory Perspective III: Theoretical Coding, Barney G. Glaser (Sociology Press, 2005. Not intended for a beginner, this book further defi nes, describes, and explicates the classic grounded theory (GT method. Perspective III lays out various facets of theoretical coding as Glaser meticulously distinguishes classic GT from other subsequent methods. Developed many years after Glaser’s classic GT, these methods, particularly as described by Strauss and Corbin, adopt the grounded theory name and engender ongoing confusion about the very premises of grounded theory. Glaser distinguishes between classic GT and the adscititious methods in his writings, referring to remodeled grounded theory and its offshoots as Qualitative Data Analysis (QDA models.

Stochastic ground motion simulation

Science.gov (United States)

Rezaeian, Sanaz; Xiaodan, Sun; Beer, Michael; Kougioumtzoglou, Ioannis A.; Patelli, Edoardo; Siu-Kui Au, Ivan

2014-01-01

Strong earthquake ground motion records are fundamental in engineering applications. Ground motion time series are used in response-history dynamic analysis of structural or geotechnical systems. In such analysis, the validity of predicted responses depends on the validity of the input excitations. Ground motion records are also used to develop ground motion prediction equations(GMPEs) for intensity measures such as spectral accelerations that are used in response-spectrum dynamic analysis. Despite the thousands of available strong ground motion records, there remains a shortage of records for large-magnitude earthquakes at short distances or in specific regions, as well as records that sample specific combinations of source, path, and site characteristics.

Communication, concepts and grounding

NARCIS (Netherlands)

van der Velde, Frank; van der Velde, F.

2015-01-01

This article discusses the relation between communication and conceptual grounding. In the brain, neurons, circuits and brain areas are involved in the representation of a concept, grounding it in perception and action. In terms of grounding we can distinguish between communication within the brain

The ground based plan

International Nuclear Information System (INIS)

1989-01-01

The paper presents a report of ''The Ground Based Plan'' of the United Kingdom Science and Engineering Research Council. The ground based plan is a plan for research in astronomy and planetary science by ground based techniques. The contents of the report contains a description of:- the scientific objectives and technical requirements (the basis for the Plan), the present organisation and funding for the ground based programme, the Plan, the main scientific features and the further objectives of the Plan. (U.K.)

Electrochemical stabilization of clayey ground

Science.gov (United States)

Rzhanitzin, B.A.; Sokoloff, V.P.

1947-01-01

Recently developed new methods of stabilization of weak grounds (e.g. the silicate treatment) are based on injection of chemical solutions into the ground. Such methods are applicable accordingly only to the kinds of ground that have the coefficient of filtration higher than 2 meters per 24 hours and permit penetration of the chemical solutions under pressure. This limit, however, as it is shown by our experience in construction, excludes a numerous and an important class of grounds, stabilization of which is indispensable in many instances. For example, digging of trenches and pits in clayey, silty, or sandy ground shows that all these types act like typical "floaters" (sluds? -S) in the presence of the ground water pressure. There were several instances in the canalization of the city of Moskow where the laying of trenches below the ground water level has led to extreme difficulties with clayey and silty ground. Similar examples could be cited in mining, engineering hydrology, and railroad construction. For these reasons, the development of methods of stabilizing such difficult types of ground has become an urgent problem of our day. In 1936, the author began his investigations, at the ground Stabilization Laboratory of VODGEO Institute, with direct electrical current as the means of stabilization of grounds. Experiments had shown that a large number of clayey types, following passage of direct electrical current, undergoes a transformation of its physico-chemical properties. It was established that the (apparent -S) density of the ground is substantially increased in consequence of the application of direct electrical current. The ground loses also its capacity to swell and to soften in water. Later, after a more detailed study of the physico-chemical mechanism of the electrical stabilization, it became possible to develop the method so as to make it applicable to sandy and silty as well as to clayey ground. By this time (1941, S.), the method has already been

Quantum Monte Carlo study of the singlet-triplet transition in ethylene

International Nuclear Information System (INIS)

El Akramine, Ouafae; Kollias, Alexander C.; Lester, William A. Jr.

2003-01-01

A theoretical study is reported of the transition between the ground state ( 1 A g ) and the lowest triplet state (1 3 B 1u ) of ethylene based on the diffusion Monte Carlo (DMC) variant of the quantum Monte Carlo method. Using DMC trial functions constructed from Hartree-Fock, complete active space self-consistent field and multi-configuration self-consistent field wave functions, we have computed the atomization energy and the heat of formation of both states, and adiabatic and vertical energy differences between these states using both all-electron and effective core potential DMC. The ground state atomization energy and heat of formation are found to agree with experiment to within the error bounds of the computation and experiment. Predictions by DMC of the triplet state atomization energy and heat of formation are presented. The adiabatic singlet-triplet energy difference is found to differ by 5 kcal/mol from the value obtained in a recent photodissociation experiment

The hydrogen tunneling splitting in malonaldehyde: A full-dimensional time-independent quantum mechanical method

Energy Technology Data Exchange (ETDEWEB)

Wu, Feng; Ren, Yinghui; Bian, Wensheng, E-mail: bian@iccas.ac.cn [Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China)

2016-08-21

The accurate time-independent quantum dynamics calculations on the ground-state tunneling splitting of malonaldehyde in full dimensionality are reported for the first time. This is achieved with an efficient method developed by us. In our method, the basis functions are customized for the hydrogen transfer process which has the effect of greatly reducing the size of the final Hamiltonian matrix, and the Lanczos method and parallel strategy are used to further overcome the memory and central processing unit time bottlenecks. The obtained ground-state tunneling splitting of 24.5 cm{sup −1} is in excellent agreement with the benchmark value of 23.8 cm{sup −1} computed with the full-dimensional, multi-configurational time-dependent Hartree approach on the same potential energy surface, and we estimate that our reported value has an uncertainty of less than 0.5 cm{sup −1}. Moreover, the role of various vibrational modes strongly coupled to the hydrogen transfer process is revealed.

Transitions in boronlike Ni XXIV, Ge XXVIII, Kr XXXII and Mo XXXVIII and fluorinelike Zr XXXII and Mo XXXIV, observed in the JET tokamak

Energy Technology Data Exchange (ETDEWEB)

Myrnaes, R [Dept. of Physics, Univ. of Lund (Sweden); Jupen, C [Dept. of Physics, Univ. of Lund (Sweden); Miecznik, G [Dept. of Physics, Univ. of Lund (Sweden); Martinson, I [Dept. of Physics, Univ. of Lund (Sweden); Denne-Hinnov, B [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

1994-01-01

Spectra of highly ionized Ni, Ge, Kr, Zr and Mo obtained from the JET tokamak have been studied. In total 20 new lines have been classified as n = 2, [Delta]n = 0 transitions in B-like and F-like ions. Among the identified lines are M1 transitions within the 2s[sup 2]2p[sup 5] [sup 2]P ground term of F-like Zr and Mo and within the 2s[sup 2]2p [sup 2]P ground term of B-like Mo. Furthermore, for B-like Ni, Kr and Mo, the 2s2p[sup 2] [sup 4]P[sub 1/2] and [sup 4]P[sub 5/2] levels, which decay by spin-forbidden transitions, have been found. From the observed wavelengths 20 new energy levels were determined. The experiments have been complemented with multiconfiguration Dirac-Fock (MCDF) calculations and semiempirical analyses of transition energies in the B I and F I isoelectronic sequences. (orig.).

A single-electron picture based on the multiconfiguration time-dependent Hartree-Fock method: application to the anisotropic ionization and subsequent high-harmonic generation of the CO molecule

Science.gov (United States)

Ohmura, S.; Kato, T.; Oyamada, T.; Koseki, S.; Ohmura, H.; Kono, H.

2018-02-01

The mechanisms of anisotropic near-IR tunnel ionization and high-order harmonic generation (HHG) in a CO molecule are theoretically investigated by using the multiconfiguration time-dependent Hartree-Fock (MCTDHF) method developed for the simulation of multielectron dynamics of molecules. The multielectron dynamics obtained by numerically solving the equations of motion (EOMs) in the MCTDHF method is converted to a single orbital picture in the natural orbital representation where the first-order reduced density matrix is diagonalized. The ionization through each natural orbital is examined and the process of HHG is classified into different optical paths designated by a combinations of initial, intermediate and final natural orbitals. The EOMs for natural spin-orbitals are also derived within the framework of the MCTDHF, which maintains the first-order reduced density matrix to be a diagonal one throughout the time propagation of a many-electron wave function. The orbital dependent, time-dependent effective potentials that govern the dynamics of respective time-dependent natural orbitals are deduced from the derived EOMs, of which the temporal variation can be used to interpret the motion of the electron density associated with each natural spin-orbital. The roles of the orbital shape, multiorbital ionization, linear Stark effect and multielectron interaction in the ionization and HHG of a CO molecule are revealed by the effective potentials obtained. When the laser electric field points to the nucleus O from C, tunnel ionization from the C atom side is enhanced; a hump structure originating from multielectron interaction is then formed on the top of the field-induced distorted barrier of the HOMO effective potential. This hump formation, responsible for the directional anisotropy of tunnel ionization, restrains the influence of the linear Stark effect on the energy shifts of bound states.

30 CFR 75.803 - Fail safe ground check circuits on high-voltage resistance grounded systems.

Science.gov (United States)

2010-07-01

... High-Voltage Distribution § 75.803 Fail safe ground check circuits on high-voltage resistance grounded systems. [Statutory Provisions] On and after September 30, 1970, high-voltage, resistance grounded systems... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fail safe ground check circuits on high-voltage...

Ground rubber: Sorption media for ground water containing benzene and O-xylene

International Nuclear Information System (INIS)

Kershaw, D.S.; Pamukcu, S.

1997-01-01

The purpose of the current study is to examine the ability of ground rubber to sorb benzene and O-xylene from water contained with aromatic hydrocarbons. The study consisted of running both batch and packed bed column tests to determine the sorption capacity, the required sorption equilibration time, and the flow through utilization efficiency of ground rubber under various contact times when exposed to water contaminated with various amounts of benzene or O-xylene. Initial batch test results indicate that ground rubber can attain equilibrium sorption capacities up to 1.3 or 8.2 mg of benzene or O-xylene, respectively, per gram of tire rubber at solution equilibrium concentrations of 10 mg/L. Packed bed column tests indicate that ground tire rubber has on the average a 40% utilization rate when a hydraulic residence time of 15 min is used. Possible future uses of round rubber as a sorption media could include, but are not limited to, the use of ground rubber as an aggregate in slurry cutoff walls that are in contact with petroleum products. Ground rubber could also be used as a sorption media in pump-and-treat methodologies or as a sorption media in in-situ reactive permeable barriers

Transitions in midwestern ground water law

International Nuclear Information System (INIS)

Bowman, J.A.; Clark, G.R.

1989-01-01

The evolution of ground-water law in eight states in the Midwest (Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Ohio, and Wisconsin) is examined, and a review of transitions in ground-water doctrines is presented. Two underlying themes in changing ground-water management are communicated. First, ground-water law is evolving from private property rules of capture based on the absolute ownership doctrines to rules requiring conservation and sharing of ground water as a public resource. Second, in both courts and state legislatures, a proactive role of ground-water management is emerging, again, with an emphasis on sharing. Both of these trends are apparent in the Midwest. In the last decade midwestern states have (1) seen significant shifts in court decisions on ground-water use with greater recognition of the reciprocal or mutually dependent nature of ground-water rights, and (2) seen increased legislative development of comprehensive ground-water management statutes that emphasize the reciprocal liabilities of ground-water use. These trends are examined and ground-water management programs discussed for eight states in the Midwest

The Grounded Theory Bookshelf

Directory of Open Access Journals (Sweden)

Vivian B. Martin, Ph.D.

2005-03-01

Full Text Available Bookshelf will provide critical reviews and perspectives on books on theory and methodology of interest to grounded theory. This issue includes a review of Heaton’s Reworking Qualitative Data, of special interest for some of its references to grounded theory as a secondary analysis tool; and Goulding’s Grounded Theory: A practical guide for management, business, and market researchers, a book that attempts to explicate the method and presents a grounded theory study that falls a little short of the mark of a fully elaborated theory.Reworking Qualitative Data, Janet Heaton (Sage, 2004. Paperback, 176 pages, $29.95. Hardcover also available.

Grounded theory in music therapy research.

Science.gov (United States)

O'Callaghan, Clare

2012-01-01

Grounded theory is one of the most common methodologies used in constructivist (qualitative) music therapy research. Researchers use the term "grounded theory" when denoting varying research designs and theoretical outcomes. This may be challenging for novice researchers when considering whether grounded theory is appropriate for their research phenomena. This paper examines grounded theory within music therapy research. Grounded theory is briefly described, including some of its "contested" ideas. A literature search was conducted using the descriptor "music therapy and grounded theory" in Pubmed, CINAHL PsychlNFO, SCOPUS, ERIC (CSA), Web of Science databases, and a music therapy monograph series. A descriptive analysis was performed on the uncovered studies to examine researched phenomena, grounded theory methods used, and how findings were presented, Thirty music therapy research projects were found in refereed journals and monographs from 1993 to "in press." The Strauss and Corbin approach to grounded theory dominates the field. Descriptors to signify grounded theory components in the studies greatly varied. Researchers have used partial or complete grounded theory methods to examine clients', family members', staff, music therapy "overhearers," music therapists', and students' experiences, as well as music therapy creative products and professional views, issues, and literature. Seven grounded theories were offered. It is suggested that grounded theory researchers clarify what and who inspired their design, why partial grounded theory methods were used (when relevant), and their ontology. By elucidating assumptions underpinning the data collection, analysis, and findings' contribution, researchers will continue to improve music therapy research using grounded theory methods.

Communication, concepts and grounding.

Science.gov (United States)

van der Velde, Frank

2015-02-01

This article discusses the relation between communication and conceptual grounding. In the brain, neurons, circuits and brain areas are involved in the representation of a concept, grounding it in perception and action. In terms of grounding we can distinguish between communication within the brain and communication between humans or between humans and machines. In the first form of communication, a concept is activated by sensory input. Due to grounding, the information provided by this communication is not just determined by the sensory input but also by the outgoing connection structure of the conceptual representation, which is based on previous experiences and actions. The second form of communication, that between humans or between humans and machines, is influenced by the first form. In particular, a more successful interpersonal communication might require forms of situated cognition and interaction in which the entire representations of grounded concepts are involved. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ground-water travel time

International Nuclear Information System (INIS)

Bentley, H.; Grisak, G.

1985-01-01

The Containment and Isolation Working Group considered issues related to the postclosure behavior of repositories in crystalline rock. This working group was further divided into subgroups to consider the progress since the 1978 GAIN Symposium and identify research needs in the individual areas of regional ground-water flow, ground-water travel time, fractional release, and cumulative release. The analysis and findings of the Ground-Water Travel Time Subgroup are presented

Regional ground-water system

International Nuclear Information System (INIS)

Long, J.

1985-01-01

The Containment and Isolation Working Group considered issues related to the postclosure behavior of repositories in crystalline rock. This working group was further divided into subgroups to consider the progress since the 1978 GAIN Symposium and identify research needs in the individual areas of regional ground-water flow, ground-water travel time, fractional release, and cumulative release. The analysis and findings of the Ground-Water Regime Subgroup are presented

Integration of a satellite ground support system based on analysis of the satellite ground support domain

Science.gov (United States)

Pendley, R. D.; Scheidker, E. J.; Levitt, D. S.; Myers, C. R.; Werking, R. D.

1994-11-01

This analysis defines a complete set of ground support functions based on those practiced in real space flight operations during the on-orbit phase of a mission. These functions are mapped against ground support functions currently in use by NASA and DOD. Software components to provide these functions can be hosted on RISC-based work stations and integrated to provide a modular, integrated ground support system. Such modular systems can be configured to provide as much ground support functionality as desired. This approach to ground systems has been widely proposed and prototyped both by government institutions and commercial vendors. The combined set of ground support functions we describe can be used as a standard to evaluate candidate ground systems. This approach has also been used to develop a prototype of a modular, loosely-integrated ground support system, which is discussed briefly. A crucial benefit to a potential user is that all the components are flight-qualified, thus giving high confidence in their accuracy and reliability.

SLG(Single-Line-to-Ground Fault Location in NUGS(Neutral Un-effectively Grounded System

Directory of Open Access Journals (Sweden)

Zhang Wenhai

2018-01-01

Full Text Available This paper reviews the SLG(Single-Line-to-Ground fault location methods in NUGS(Neutral Un-effectively Grounded System, including ungrounded system, resonant grounded system and high-resistance grounded system which are widely used in Northern Europe and China. This type of fault is hard to detect and location because fault current is the sum of capacitance current of the system which is always small(about tens of amperes. The characteristics of SLG fault in NUGS and the fault location methods are introduced in the paper.

Yet Another Puzzle of Ground

NARCIS (Netherlands)

Korbmacher, J.

2015-01-01

We show that any predicational theory of partial ground that extends a standard theory of syntax and that proves some commonly accepted principles for partial ground is inconsistent. We suggest a way to obtain a consistent predicational theory of ground.

A Mixed Prediction Model of Ground Subsidence for Civil Infrastructures on Soft Ground

Directory of Open Access Journals (Sweden)

Kiyoshi Kobayashi

2012-01-01

Full Text Available The estimation of ground subsidence processes is an important subject for the asset management of civil infrastructures on soft ground, such as airport facilities. In the planning and design stage, there exist many uncertainties in geotechnical conditions, and it is impossible to estimate the ground subsidence process by deterministic methods. In this paper, the sets of sample paths designating ground subsidence processes are generated by use of a one-dimensional consolidation model incorporating inhomogeneous ground subsidence. Given the sample paths, the mixed subsidence model is presented to describe the probabilistic structure behind the sample paths. The mixed model can be updated by the Bayesian methods based upon the newly obtained monitoring data. Concretely speaking, in order to estimate the updating models, Markov Chain Monte Calro method, which is the frontier technique in Bayesian statistics, is applied. Through a case study, this paper discussed the applicability of the proposed method and illustrated its possible application and future works.

Ground penetrating radar system and method for detecting an object on or below a ground surface

NARCIS (Netherlands)

De Jongth, R.; Yarovoy, A.; Schukin, A.

2001-01-01

Ground penetrating radar system for detecting objects (17) on or below a ground surface (18), comprising at least one transmit antenna (13) having a first foot print (14) at the ground surface, at least one receive antenna (15) having a second foot print (16) at the ground surface, and processing

Electrical Ground System Design of PEFP

International Nuclear Information System (INIS)

Mun, Kyeong Jun; Jeon, Gye Po; Park, Sung Sik; Min, Yi Sub; Nam, Jung Min; Cho, Jang Hyung; Kim, Jun Yeon

2010-01-01

Since host site host site was selected Gyeong-ju city in January, 2006. we need design revision of Proton Accelerator research center to reflect on host site characteristics and several conditions. In this paper, electrical grounding and lightning protection design scheme is introduced. In electrical grounding system design of PEFP, we classified electrical facilities into 4 groups; equipment grounding (type A), instrument grounding (Type A), high frequency instrument grounding (Type C) and lightning arrestor grounding (Type D). Lightning protection system is designed in all buildings of proton accelerator research center of PEFP, including switchyard

Electrical Ground System Design of PEFP

Energy Technology Data Exchange (ETDEWEB)

Mun, Kyeong Jun; Jeon, Gye Po; Park, Sung Sik; Min, Yi Sub; Nam, Jung Min; Cho, Jang Hyung; Kim, Jun Yeon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2010-10-15

Since host site host site was selected Gyeong-ju city in January, 2006. we need design revision of Proton Accelerator research center to reflect on host site characteristics and several conditions. In this paper, electrical grounding and lightning protection design scheme is introduced. In electrical grounding system design of PEFP, we classified electrical facilities into 4 groups; equipment grounding (type A), instrument grounding (Type A), high frequency instrument grounding (Type C) and lightning arrestor grounding (Type D). Lightning protection system is designed in all buildings of proton accelerator research center of PEFP, including switchyard

Ground water and earthquakes

Energy Technology Data Exchange (ETDEWEB)

Ts' ai, T H

1977-11-01

Chinese folk wisdom has long seen a relationship between ground water and earthquakes. Before an earthquake there is often an unusual change in the ground water level and volume of flow. Changes in the amount of particulate matter in ground water as well as changes in color, bubbling, gas emission, and noises and geysers are also often observed before earthquakes. Analysis of these features can help predict earthquakes. Other factors unrelated to earthquakes can cause some of these changes, too. As a first step it is necessary to find sites which are sensitive to changes in ground stress to be used as sensor points for predicting earthquakes. The necessary features are described. Recording of seismic waves of earthquake aftershocks is also an important part of earthquake predictions.

On LHCb muon MWPC grounding

CERN Document Server

Kashchuk, A

2006-01-01

My goal is to study how a big MWPC system, in particular the LHCb muon system, can be protected against unstable operation and multiple spurious hits, produced by incorrect or imperfect grounding in the severe EM environment of the LHCb experiment. A mechanism of penetration of parasitic current from the ground loop to the input of the front-end amplifier is discussed. A new model of the detector cell as the electrical bridge is considered. As shown, unbalance of the bridge makes detector to be sensitive to the noise in ground loop. Resonances in ground loop are specified. Tests of multiple-point and single-point grounding conceptions made on mock-up are presented.

Exogenous spatial attention influences figure-ground assignment.

Science.gov (United States)

Vecera, Shaun P; Flevaris, Anastasia V; Filapek, Joseph C

2004-01-01

In a hierarchical stage account of vision, figure-ground assignment is thought to be completed before the operation of focal spatial attention. Results of previous studies have supported this account by showing that unpredictive, exogenous spatial precues do not influence figure-ground assignment, although voluntary attention can influence figure-ground assignment. However, in these studies, attention was not summoned directly to a region in a figure-ground display. In three experiments, we addressed the relationship between figure-ground assignment and visuospatial attention. In Experiment 1, we replicated the finding that exogenous precues do not influence figure-ground assignment when they direct attention outside of a figure-ground stimulus. In Experiment 2, we demonstrated that exogenous attention can influence figure-ground assignment if it is directed to one of the regions in a figure-ground stimulus. In Experiment 3, we demonstrated that exogenous attention can influence figure-ground assignment in displays that contain a Gestalt figure-ground cue; this result suggests that figure-ground processes are not entirely completed prior to the operation of focal spatial attention. Exogenous spatial attention acts as a cue for figure-ground assignment and can affect the outcome of figure-ground processes.

Cerocene Revisited: The Electronic Structure of and Interconversion Between Ce2(C8H8)3 and Ce(C8H8)2

Energy Technology Data Exchange (ETDEWEB)

Walter, Marc D.; Booth, Corwin H.; Lukens, Wayne W.; Andersen, Richard A.

2009-02-02

New synthetic procedures for the preparation of Ce(cot)2, cerocene, from [Li(thf)4][Ce(cot)2], and Ce2(cot)3 in high yield and purity are reported. Heating solid Ce(cot)2 yields Ce2(cot)3 and COT while heating Ce2(cot)3 with an excess of COT in C6D6 to 65oC over four months yields Ce(cot)2. The solid state magnetic susceptibility of these three organocerium compounds shows that Ce(cot)2 behaves as a TIP (temperature independent paramagnet) over the temperature range of 5-300 K, while that of Ce2(cot)3 shows that the spin carriers are antiferromagnetically coupled below 10 K; above 10 K, the individual spins are uncorrelated, and [Ce(cot)2]- behaves as an isolated f1 paramagnet. The EPR at 1.5K for Ce2(cot)3 and [Ce(cot)2]- have ground state of MJ= +- 1/2. The LIII edge XANES of Ce(cot)2 (Booth, C.H.; Walter, M.D.; Daniel, M.; Lukens, W.W., Andersen, R.A., Phys. Rev. Lett. 2005, 95, 267202) and 2Ce2(cot)3 over 30-500 K are reported; the Ce(cot)2 XANES spectra show Ce(III) and Ce(IV) signatures up to a temperature of approximately 500 K, whereupon the Ce(IV) signature disappears, consistent with the thermal behavior observed in the melting experiment. The EXAFS of Ce(cot)2 and Ce2(cot)3 are reported at 30 K; the agreement between the molecular parameters for Ce(cot)2 derived from EXAFS and single crystal X-ray diffraction data are excellent. In the case of Ce2(cot)3 no X-ray diffraction data are known to exist, but the EXAFS are consistent with a"triple-decker" sandwich structure. A molecular rationalization is presented for the electronic structure of cerocene having a multiconfiguration ground state that is an admixture of the two configurations Ce(III, 4f1)(cot1.5-)2 and Ce(IV, 4f0)(cot2-)2; the multiconfigurational ground state has profound effects on the magnetic properties and on the nature of the chemical bond in cerocene and, perhaps, other molecules.

All Electron ab initio Investigations of the Three Lowest Lying Electronic States of the RuC Molecule

DEFF Research Database (Denmark)

Shim, Irene; Gingerich, K. A.

2000-01-01

The three lowest-lying electronic states of RuC, (1)Sigma(+), (3)Delta, and (1)Delta, have been investigated by performing all-electron ab initio multi-configuration self-consistent-field (CASSCF) and multi-reference configuration interaction (MRCI) calculations including relativistic corrections....... The electronic ground state is derived as (1)Sigma(+) with the spectroscopic constants r(e) = 1.616 Angstrom and omega(e) = 1085 cm(-1). The lowest-lying excited state, (3)Delta, has r(e) = 1.632 Angstrom, omega(e) = 1063 cm(-1), and T-e = 912 cm(-1). These results are consistent with recent spectroscopic values....... The chemical bonds in all three lowest-lying states are triple bonds composed of one sigma and two pi bonds. (C) 2000 Elsevier Science B.V. All rights reserved....

Ground-motion prediction from tremor

Science.gov (United States)

Baltay, Annemarie S.; Beroza, Gregory C.

2013-01-01

The widespread occurrence of tremor, coupled with its frequency content and location, provides an exceptional opportunity to test and improve strong ground-motion attenuation relations for subduction zones. We characterize the amplitude of thousands of individual 5 min tremor events in Cascadia during three episodic tremor and slip events to constrain the distance decay of peak ground acceleration (PGA) and peak ground velocity (PGV). We determine the anelastic attenuation parameter for ground-motion prediction equations (GMPEs) to a distance of 150 km, which is sufficient to place important constraints on ground-motion decay. Tremor PGA and PGV show a distance decay that is similar to subduction-zone-specific GMPEs developed from both data and simulations; however, the massive amount of data present in the tremor observations should allow us to refine distance-amplitude attenuation relationships for use in hazard maps, and to search for regional variations and intrasubduction zone differences in ground-motion attenuation.

Ground Control System Description Document

International Nuclear Information System (INIS)

Eric Loros

2001-01-01

The Ground Control System contributes to the safe construction and operation of the subsurface facility, including accesses and waste emplacement drifts, by maintaining the configuration and stability of the openings during construction, development, emplacement, and caretaker modes for the duration of preclosure repository life. The Ground Control System consists of ground support structures installed within the subsurface excavated openings, any reinforcement made to the rock surrounding the opening, and inverts if designed as an integral part of the system. The Ground Control System maintains stability for the range of geologic conditions expected at the repository and for all expected loading conditions, including in situ rock, construction, operation, thermal, and seismic loads. The system maintains the size and geometry of operating envelopes for all openings, including alcoves, accesses, and emplacement drifts. The system provides for the installation and operation of sensors and equipment for any required inspection and monitoring. In addition, the Ground Control System provides protection against rockfall for all subsurface personnel, equipment, and the engineered barrier system, including the waste package during the preclosure period. The Ground Control System uses materials that are sufficiently maintainable and that retain the necessary engineering properties for the anticipated conditions of the preclosure service life. These materials are also compatible with postclosure waste isolation performance requirements of the repository. The Ground Control System interfaces with the Subsurface Facility System for operating envelopes, drift orientation, and excavated opening dimensions, Emplacement Drift System for material compatibility, Monitored Geologic Repository Operations Monitoring and Control System for ground control instrument readings, Waste Emplacement/Retrieval System to support waste emplacement operations, and the Subsurface Excavation System

Transonic and supersonic ground effect aerodynamics

Science.gov (United States)

Doig, G.

2014-08-01

A review of recent and historical work in the field of transonic and supersonic ground effect aerodynamics has been conducted, focussing on applied research on wings and aircraft, present and future ground transportation, projectiles, rocket sleds and other related bodies which travel in close ground proximity in the compressible regime. Methods for ground testing are described and evaluated, noting that wind tunnel testing is best performed with a symmetry model in the absence of a moving ground; sled or rail testing is ultimately preferable, though considerably more expensive. Findings are reported on shock-related ground influence on aerodynamic forces and moments in and accelerating through the transonic regime - where force reversals and the early onset of local supersonic flow is prevalent - as well as more predictable behaviours in fully supersonic to hypersonic ground effect flows.

Ground reaction forces during level ground walking with body weight unloading

Science.gov (United States)

Barela, Ana M. F.; de Freitas, Paulo B.; Celestino, Melissa L.; Camargo, Marcela R.; Barela, José A.

2014-01-01

Background: Partial body weight support (BWS) systems have been broadly used with treadmills as a strategy for gait training of individuals with gait impairments. Considering that we usually walk on level ground and that BWS is achieved by altering the load on the plantar surface of the foot, it would be important to investigate some ground reaction force (GRF) parameters in healthy individuals walking on level ground with BWS to better implement rehabilitation protocols for individuals with gait impairments. Objective: To describe the effects of body weight unloading on GRF parameters as healthy young adults walked with BWS on level ground. Method: Eighteen healthy young adults (27±4 years old) walked on a walkway, with two force plates embedded in the middle of it, wearing a harness connected to a BWS system, with 0%, 15%, and 30% BWS. Vertical and horizontal peaks and vertical valley of GRF, weight acceptance and push-off rates, and impulse were calculated and compared across the three experimental conditions. Results: Overall, participants walked more slowly with the BWS system on level ground compared to their normal walking speed. As body weight unloading increased, the magnitude of the GRF forces decreased. Conversely, weight acceptance rate was similar among conditions. Conclusions: Different amounts of body weight unloading promote different outputs of GRF parameters, even with the same mean walk speed. The only parameter that was similar among the three experimental conditions was the weight acceptance rate. PMID:25590450

Ground reaction forces during level ground walking with body weight unloading

Directory of Open Access Journals (Sweden)

Ana M. F. Barela

2014-12-01

Full Text Available Background: Partial body weight support (BWS systems have been broadly used with treadmills as a strategy for gait training of individuals with gait impairments. Considering that we usually walk on level ground and that BWS is achieved by altering the load on the plantar surface of the foot, it would be important to investigate some ground reaction force (GRF parameters in healthy individuals walking on level ground with BWS to better implement rehabilitation protocols for individuals with gait impairments. Objective: To describe the effects of body weight unloading on GRF parameters as healthy young adults walked with BWS on level ground. Method: Eighteen healthy young adults (27±4 years old walked on a walkway, with two force plates embedded in the middle of it, wearing a harness connected to a BWS system, with 0%, 15%, and 30% BWS. Vertical and horizontal peaks and vertical valley of GRF, weight acceptance and push-off rates, and impulse were calculated and compared across the three experimental conditions. Results: Overall, participants walked more slowly with the BWS system on level ground compared to their normal walking speed. As body weight unloading increased, the magnitude of the GRF forces decreased. Conversely, weight acceptance rate was similar among conditions. Conclusions: Different amounts of body weight unloading promote different outputs of GRF parameters, even with the same mean walk speed. The only parameter that was similar among the three experimental conditions was the weight acceptance rate.

14 CFR 417.109 - Ground safety.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Ground safety. 417.109 Section 417.109... TRANSPORTATION LICENSING LAUNCH SAFETY Launch Safety Responsibilities § 417.109 Ground safety. (a) Ground safety... 417.115(c), and subpart E of this part provide launch operator ground safety requirements. ...

Synthesis of High-Frequency Ground Motion Using Information Extracted from Low-Frequency Ground Motion

Science.gov (United States)

Iwaki, A.; Fujiwara, H.

2012-12-01

Broadband ground motion computations of scenario earthquakes are often based on hybrid methods that are the combinations of deterministic approach in lower frequency band and stochastic approach in higher frequency band. Typical computation methods for low-frequency and high-frequency (LF and HF, respectively) ground motions are the numerical simulations, such as finite-difference and finite-element methods based on three-dimensional velocity structure model, and the stochastic Green's function method, respectively. In such hybrid methods, LF and HF wave fields are generated through two different methods that are completely independent of each other, and are combined at the matching frequency. However, LF and HF wave fields are essentially not independent as long as they are from the same event. In this study, we focus on the relation among acceleration envelopes at different frequency bands, and attempt to synthesize HF ground motion using the information extracted from LF ground motion, aiming to propose a new method for broad-band strong motion prediction. Our study area is Kanto area, Japan. We use the K-NET and KiK-net surface acceleration data and compute RMS envelope at four frequency bands: 0.5-1.0 Hz, 1.0-2.0 Hz, 2.0-4.0 Hz, .0-8.0 Hz, and 8.0-16.0 Hz. Taking the ratio of the envelopes of adjacent bands, we find that the envelope ratios have stable shapes at each site. The empirical envelope-ratio characteristics are combined with low-frequency envelope of the target earthquake to synthesize HF ground motion. We have applied the method to M5-class earthquakes and a M7 target earthquake that occurred in the vicinity of Kanto area, and successfully reproduced the observed HF ground motion of the target earthquake. The method can be applied to a broad band ground motion simulation for a scenario earthquake by combining numerically-computed low-frequency (~1 Hz) ground motion with the empirical envelope ratio characteristics to generate broadband ground motion

Electrical Subsurface Grounding Analysis

International Nuclear Information System (INIS)

J.M. Calle

2000-01-01

The purpose and objective of this analysis is to determine the present grounding requirements of the Exploratory Studies Facility (ESF) subsurface electrical system and to verify that the actual grounding system and devices satisfy the requirements

Participation of Co-Ligands in Electronic Transitions of Platinum(II) Diazabutadiene Complexes

Czech Academy of Sciences Publication Activity Database

Klein, A.; Slageren van, J.; Záliš, Stanislav

2002-01-01

Roč. 41, č. 20 (2002), s. 5216-5225 ISSN 0020-1669 R&D Projects: GA MŠk ME 439; GA MŠk OC D14.20 Institutional research plan: CEZ:AV0Z4040901 Keywords : molecular photochemical device * resonance Raman-spectra * alpha-diimine ligands Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.950, year: 2002

Simulation of ground-water flow and land subsidence in the Antelope Valley ground-water basin, California

Science.gov (United States)

Leighton, David A.; Phillips, Steven P.

2003-01-01

Antelope Valley, California, is a topographically closed basin in the western part of the Mojave Desert, about 50 miles northeast of Los Angeles. The Antelope Valley ground-water basin is about 940 square miles and is separated from the northern part of Antelope Valley by faults and low-lying hills. Prior to 1972, ground water provided more than 90 percent of the total water supply in the valley; since 1972, it has provided between 50 and 90 percent. Most ground-water pumping in the valley occurs in the Antelope Valley ground-water basin, which includes the rapidly growing cities of Lancaster and Palmdale. Ground-water-level declines of more than 200 feet in some parts of the ground-water basin have resulted in an increase in pumping lifts, reduced well efficiency, and land subsidence of more than 6 feet in some areas. Future urban growth and limits on the supply of imported water may continue to increase reliance on ground water. To better understand the ground-water flow system and to develop a tool to aid in effectively managing the water resources, a numerical model of ground-water flow and land subsidence in the Antelope Valley ground-water basin was developed using old and new geohydrologic information. The ground-water flow system consists of three aquifers: the upper, middle, and lower aquifers. The aquifers, which were identified on the basis of the hydrologic properties, age, and depth of the unconsolidated deposits, consist of gravel, sand, silt, and clay alluvial deposits and clay and silty clay lacustrine deposits. Prior to ground-water development in the valley, recharge was primarily the infiltration of runoff from the surrounding mountains. Ground water flowed from the recharge areas to discharge areas around the playas where it discharged either from the aquifer system as evapotranspiration or from springs. Partial barriers to horizontal ground-water flow, such as faults, have been identified in the ground-water basin. Water-level declines owing to

30 CFR 77.803 - Fail safe ground check circuits on high-voltage resistance grounded systems.

Science.gov (United States)

2010-07-01

... circuits on high-voltage resistance grounded systems. On and after September 30, 1971, all high-voltage... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fail safe ground check circuits on high-voltage resistance grounded systems. 77.803 Section 77.803 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION...

A Study on the Improvement Effect and Field Applicability of the Deep Soft Ground by Ground Heating Method

Directory of Open Access Journals (Sweden)

Mincheol Park

2018-05-01

Full Text Available The soft ground in coastal areas should be treated when it needs to be used for the sustainably developed of urban or industrial complex constructions. The ground heating method for soft ground improvement was applied in Eastern Europe in the 1960s, but it was not widely used due to economic and environmental problems. The author developed a device for improving soft ground using an electric heating pipe. This paper investigates the improvement effect and field application of deep soft ground by the ground heating method using the electric heating pipe. Ground heating increases the temperature of the deep soft ground and increases the tip resistance of the static electronic piezo-cone penetration test. Additionally, the pressure of the pore water decreases because the pore water is evaporated due to the ground heating. As a result of the experiment, it was verified that there was an improvement in the effect of deep soft ground by the ground heating method. With ground heating for 96 h, the tip resistance was increased by 61% at a point 0.35 m horizontally away from the electric heat pipe, 22% at 0.97 m, and 2% at 1.31 m. As a result of the field test, it was found that there were no problems in the power supply of the diesel generator and the control panel. It was easy to install the electric heating pipes in the deep soft ground. However, due to boring, the ground was disturbed and water vapor was discharged through this gap. To minimize the discharge of water vapor, it is necessary to drive the electric heating pipe.

Proven Innovations and New Initiatives in Ground System Development: Reducing Costs in the Ground System

Science.gov (United States)

Gunn, Jody M.

2006-01-01

The state-of-the-practice for engineering and development of Ground Systems has evolved significantly over the past half decade. Missions that challenge ground system developers with significantly reduced budgets in spite of requirements for greater and previously unimagined functionality are now the norm. Making the right trades early in the mission lifecycle is one of the key factors to minimizing ground system costs. The Mission Operations Strategic Leadership Team at the Jet Propulsion Laboratory has spent the last year collecting and working through successes and failures in ground systems for application to future missions.

Application of Electromagnetic Induction to Monitor Changes in Soil Electrical Conductivity Profiles in Arid Agriculture

KAUST Repository

Jadoon, K.Z.

2015-09-06

In this research, multi-configuration electromagnetic induction (EMI) measurements were conducted in a corn field to estimate variation in soil electrical conductivity profiles in the roots zone. Electromagnetic forward model based on the full solution of Maxwell\\'s equation was used to simulate the apparent electrical conductivity measured with EMI system (the CMD mini-Explorer). Joint inversion of multi-configuration EMI measurements were performed to estimate the vertical soil electrical conductivity profiles. The inversion minimizes the misfit between the measured and modeled soil apparent electrical conductivity by DiffeRential Evolution Adaptive Metropolis (DREAM) algorithm, which is based on Bayesain approach. Results indicate that soil electrical conductivity profiles have low values close to the corn plants, which indicates loss of soil moisture due to the root water uptake. These results offer valuable insights into future potential and emerging challenges in the development of joint analysis of multi-configuration EMI measurements to retrieve effective soil electrical conductivity profiles.

Ground-water sample collection and analysis plan for the ground-water surveillance project

International Nuclear Information System (INIS)

Bryce, R.W.; Evans, J.C.; Olsen, K.B.

1991-12-01

The Pacific Northwest Laboratory performs ground-water sampling activities at the US Department of Energy's (DOE's) Hanford Site in support of DOE's environmental surveillance responsibilities. The purpose of this document is to translate DOE's General Environmental Protection Program (DOE Order 5400.1) into a comprehensive ground-water sample collection and analysis plan for the Hanford Site. This sample collection and analysis plan sets forth the environmental surveillance objectives applicable to ground water, identifies the strategy for selecting sample collection locations, and lists the analyses to be performed to meet those objectives

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.

Performance Analysis of Slinky Horizontal Ground Heat Exchangers for a Ground Source Heat Pump System

Directory of Open Access Journals (Sweden)

Md. Hasan Ali

2017-10-01

Full Text Available This paper highlights the thermal performance of reclined (parallel to ground surface and standing (perpendicular to ground surface slinky horizontal ground heat exchangers (HGHEs with different water mass flow rates in the heating mode of continuous and intermittent operations. A copper tube with an outer surface protected with low-density polyethylene was selected as the tube material of the ground heat exchanger. Effects on ground temperature around the reclined slinky HGHE due to heat extraction and the effect of variation of ground temperatures on reclined HGHE performance are discussed. A higher heat exchange rate was experienced in standing HGHE than in reclined HGHE. The standing HGHE was affected by deeper ground temperature and also a greater amount of backfilled sand in standing HGHE (4.20 m3 than reclined HGHE (1.58 m3, which has higher thermal conductivity than site soil. For mass flow rate of 1 L/min with inlet water temperature 7 °C, the 4-day average heat extraction rates increased 45.3% and 127.3%, respectively, when the initial average ground temperatures at 1.5 m depth around reclined HGHE increased from 10.4 °C to 11.7 °C and 10.4 °C to 13.7 °C. In the case of intermittent operation, which boosted the thermal performance, a short time interval of intermittent operation is better than a long time interval of intermittent operation. Furthermore, from the viewpoint of power consumption by the circulating pump, the intermittent operation is more efficient than continuous operation.

30 CFR 57.3360 - Ground support use.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Ground support use. 57.3360 Section 57.3360... and Support-Underground Only § 57.3360 Ground support use. Ground support shall be used where ground conditions, or mining experience in similar ground conditions in the mine, indicate that it is necessary...

On Grounding of Fast Ships

DEFF Research Database (Denmark)

Simonsen, Bo Cerup; Pedersen, Preben Terndrup

1997-01-01

The paper deals with analysis of grounding of high-speed crafts. It is the purpose to present a comprehensive mathematical model for calculation of the overall dynamic ship response during grounding. This procedure is applied to derive the motions, the time varying sectional forces and the local...... loads during grounding on plane, sloping, sandy bottoms for six different designs of fast monohull ships made from steel, aluminium or GRP sandwich materials. The results show that the effect of the hull flexibility is to reduce the overall dynamic sectional loads on the hull girder. The considered...... numerical examples also indicate that, even with impact speeds of 40 knots against a 1:10 sloping bottom, the global strength of the hull girder is not exceeded by the grounding induced loads.For the local deformation of high-speed ship hulls at the point of contact with the ground, the paper presents...

46 CFR 111.05-13 - Grounding connection.

Science.gov (United States)

2010-10-01

... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Equipment Ground, Ground Detection, and Grounded Systems § 111.05-13 Grounding... power sources operating in parallel in the system. ...

Using Simulated Ground Motions to Constrain Near-Source Ground Motion Prediction Equations in Areas Experiencing Induced Seismicity

Science.gov (United States)

Bydlon, S. A.; Dunham, E. M.

2016-12-01

Recent increases in seismic activity in historically quiescent areas such as Oklahoma, Texas, and Arkansas, including large, potentially induced events such as the 2011 Mw 5.6 Prague, OK, earthquake, have spurred the need for investigation into expected ground motions associated with these seismic sources. The neoteric nature of this seismicity increase corresponds to a scarcity of ground motion recordings within 50 km of earthquakes Mw 3.0 and greater, with increasing scarcity at larger magnitudes. Gathering additional near-source ground motion data will help better constraints on regional ground motion prediction equations (GMPEs) and will happen over time, but this leaves open the possibility of damaging earthquakes occurring before potential ground shaking and seismic hazard in these areas are properly understood. To aid the effort of constraining near-source GMPEs associated with induced seismicity, we integrate synthetic ground motion data from simulated earthquakes into the process. Using the dynamic rupture and seismic wave propagation code waveqlab3d, we perform verification and validation exercises intended to establish confidence in simulated ground motions for use in constraining GMPEs. We verify the accuracy of our ground motion simulator by performing the PEER/SCEC layer-over-halfspace comparison problem LOH.1 Validation exercises to ensure that we are synthesizing realistic ground motion data include comparisons to recorded ground motions for specific earthquakes in target areas of Oklahoma between Mw 3.0 and 4.0. Using a 3D velocity structure that includes a 1D structure with additional small-scale heterogeneity, the properties of which are based on well-log data from Oklahoma, we perform ground motion simulations of small (Mw 3.0 - 4.0) earthquakes using point moment tensor sources. We use the resulting synthetic ground motion data to develop GMPEs for small earthquakes in Oklahoma. Preliminary results indicate that ground motions can be amplified

Modernization of the Cassini Ground System

Science.gov (United States)

Razo, Gus; Fujii, Tammy

2014-01-01

The Cassini Spacecraft and its ground system have been operational for over 16 years. Modernization presents several challenges due to the personnel, processes, and tools already invested and embedded into the current ground system structure. Every mission's ground system has its own unique complexities and challenges, involving various organizational units. As any mission from its inception to its execution, schedules are always tight. This forces GDS engineers to implement a working ground system that is not necessarily fully optimized. Ground system challenges increase as technology evolves and cyber threats become more sophisticated. Cassini's main challenges were due to its ground system existing before many security requirements were levied on the multi-mission tools and networks. This caused a domino effect on Cassini GDS tools that relied on outdated technological features. In the aerospace industry reliable and established technology is preferred over innovative yet less proven technology. Loss of data for a spacecraft mission can be catastrophic; therefore, there is a reluctance to make changes and updates to the ground system. Nevertheless, all missions and associated teams face the need to modernize their processes and tools. Systems development methods from well-known system analysis and design principles can be applied to many missions' ground systems. Modernization should always be considered, but should be done in such a way that it does not affect flexibility nor interfere with established practices. Cassini has accomplished a secure and efficient ground data system through periodic updates. The obstacles faced while performing the modernization of the Cassini ground system will be outlined, as well as the advantages and challenges that were encountered.

Ground motion predictions

Energy Technology Data Exchange (ETDEWEB)

Loux, P C [Environmental Research Corporation, Alexandria, VA (United States)

1969-07-01

Nuclear generated ground motion is defined and then related to the physical parameters that cause it. Techniques employed for prediction of ground motion peak amplitude, frequency spectra and response spectra are explored, with initial emphasis on the analysis of data collected at the Nevada Test Site (NTS). NTS postshot measurements are compared with pre-shot predictions. Applicability of these techniques to new areas, for example, Plowshare sites, must be questioned. Fortunately, the Atomic Energy Commission is sponsoring complementary studies to improve prediction capabilities primarily in new locations outside the NTS region. Some of these are discussed in the light of anomalous seismic behavior, and comparisons are given showing theoretical versus experimental results. In conclusion, current ground motion prediction techniques are applied to events off the NTS. Predictions are compared with measurements for the event Faultless and for the Plowshare events, Gasbuggy, Cabriolet, and Buggy I. (author)

Ground motion predictions

International Nuclear Information System (INIS)

Loux, P.C.

1969-01-01

Nuclear generated ground motion is defined and then related to the physical parameters that cause it. Techniques employed for prediction of ground motion peak amplitude, frequency spectra and response spectra are explored, with initial emphasis on the analysis of data collected at the Nevada Test Site (NTS). NTS postshot measurements are compared with pre-shot predictions. Applicability of these techniques to new areas, for example, Plowshare sites, must be questioned. Fortunately, the Atomic Energy Commission is sponsoring complementary studies to improve prediction capabilities primarily in new locations outside the NTS region. Some of these are discussed in the light of anomalous seismic behavior, and comparisons are given showing theoretical versus experimental results. In conclusion, current ground motion prediction techniques are applied to events off the NTS. Predictions are compared with measurements for the event Faultless and for the Plowshare events, Gasbuggy, Cabriolet, and Buggy I. (author)

The Development of Constructivist Grounded Theory

OpenAIRE

Jane Mills; Ann Bonner; Karen Francis

2006-01-01

Constructivist grounded theory is a popular method for research studies primarily in the disciplines of psychology, education, and nursing. In this article, the authors aim to locate the roots of constructivist grounded theory and then trace its development. They examine key grounded theory texts to discern their ontological and epistemological orientation. They find Strauss and Corbin's texts on grounded theory to possess a discernable thread of constructivism in their approach to inquiry. T...

Grounding Anger Management

Directory of Open Access Journals (Sweden)

Odis E. Simmons, PhD

2017-06-01

Full Text Available One of the things that drew me to grounded theory from the beginning was Glaser and Strauss’ assertion in The Discovery of Grounded Theory that it was useful as a “theoretical foothold” for practical applications (p. 268. From this, when I was a Ph.D student studying under Glaser and Strauss in the early 1970s, I devised a GT based approach to action I later came to call “grounded action.” In this short paper I’ll present a very brief sketch of an anger management program I developed in 1992, using grounded action. I began my research by attending a two-day anger management training workshop designed for training professionals in the most commonly used anger management model. Like other intervention programs I had seen, this model took a psychologizing and pathologizing approach to the issue. Following this, I sat through the full course of an anger management program that used this model, observing the reactions of the participants and the approach of the facilitator. Following each session I conducted open-ended interviews with most of the participants, either individually or in groups of two or three. I had also done previous research in counseling and social work contexts that turned out to be very relevant to an anger management program design.

Ground-Water Availability in the United States

Science.gov (United States)

Reilly, Thomas E.; Dennehy, Kevin F.; Alley, William M.; Cunningham, William L.

2008-01-01

Ground water is among the Nation's most important natural resources. It provides half our drinking water and is essential to the vitality of agriculture and industry, as well as to the health of rivers, wetlands, and estuaries throughout the country. Large-scale development of ground-water resources with accompanying declines in ground-water levels and other effects of pumping has led to concerns about the future availability of ground water to meet domestic, agricultural, industrial, and environmental needs. The challenges in determining ground-water availability are many. This report examines what is known about the Nation's ground-water availability and outlines a program of study by the U.S. Geological Survey Ground-Water Resources Program to improve our understanding of ground-water availability in major aquifers across the Nation. The approach is designed to provide useful regional information for State and local agencies who manage ground-water resources, while providing the building blocks for a national assessment. The report is written for a wide audience interested or involved in the management, protection, and sustainable use of the Nation's water resources.

Ground effect aerodynamics of racing cars

OpenAIRE

Zhang, Xin; Toet, Willem; Zerihan, Jonathan

2006-01-01

We review the progress made during the last thirty years on ground effect aerodynamics associated with race cars, in particular open wheel race cars. Ground effect aerodynamics of race cars is concerned with generating downforce, principally via low pressure on the surfaces nearest to the ground. The “ground effected” parts of an open wheeled car's aerodynamics are the most aerodynamically efficient and contribute less drag than that associated with, for example, an upper rear wing. Whilst dr...

Graphene ground states

Science.gov (United States)

Friedrich, Manuel; Stefanelli, Ulisse

2018-06-01

Graphene is locally two-dimensional but not flat. Nanoscale ripples appear in suspended samples and rolling up often occurs when boundaries are not fixed. We address this variety of graphene geometries by classifying all ground-state deformations of the hexagonal lattice with respect to configurational energies including two- and three-body terms. As a consequence, we prove that all ground-state deformations are either periodic in one direction, as in the case of ripples, or rolled up, as in the case of nanotubes.

Pesticides in Ground Water

DEFF Research Database (Denmark)

Bjerg, Poul Løgstrup

1996-01-01

Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588.......Review af: Jack E. Barbash & Elizabeth A. Resek (1996). Pesticides in Ground Water. Distribution trends and governing factors. Ann Arbor Press, Inc. Chelsea, Michigan. pp 588....

The Building Blocks of Life Move from Ground to Tree to Animal and Back to Ground

Science.gov (United States)

Davidson, E. A.

2015-12-01

I generally use combinations of big words to describe my science, such as biogeochemistry, ecosystem ecology, nutrient cycling, stoichiometry, tropical deforestation, land-use change, agricultural intensification, eutrophication, greenhouse gas emissions, and sustainable development. I didn't expect to use any of these words, but I was surprised that I couldn't use some others that seem simple enough to me, such as farm, plant, soil, and forest. I landed on "building blocks" as my metaphor for the forms of carbon, nitrogen, phosphorus, and other elements that I study as they cycle through and among ecosystems. I study what makes trees and other kinds of life grow. We all know that they need the sun and that they take up water from the ground, but what else do trees need from the ground? What do animals that eat leaves and wood get from the trees? Just as we need building blocks to grow our bodies, trees and animals also need building blocks for growing their bodies. Trees get part of their building blocks from the ground and animals get theirs from what they eat. When animals poop and when leaves fall, some of their building blocks return to the ground. When they die, their building blocks also go back to the ground. I also study what happens to the ground, the water, and the air when we cut down trees, kill or shoo away the animals, and make fields to grow our food. Can we grow enough food and still keep the ground, water, and air clean? I think the answer is yes, but it will take better understanding of how all of those building blocks fit together and move around, from ground to tree to animal and back to ground.

7 CFR 65.160 - Ground chicken.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Ground chicken. 65.160 Section 65.160 Agriculture... OF BEEF, PORK, LAMB, CHICKEN, GOAT MEAT, PERISHABLE AGRICULTURAL COMMODITIES, MACADAMIA NUTS, PECANS, PEANUTS, AND GINSENG General Provisions Definitions § 65.160 Ground chicken. Ground chicken means...

33 CFR 183.415 - Grounding.

Science.gov (United States)

2010-07-01

... SAFETY BOATS AND ASSOCIATED EQUIPMENT Electrical Systems Manufacturer Requirements § 183.415 Grounding. If a boat has more than one gasoline engine, grounded cranking motor circuits must be connected to...

[Mo2(CN)11]:5- A detailed description of ligand-field spectra and magnetic properties by first-principles calculations.

Science.gov (United States)

Hendrickx, Marc F A; Clima, S; Chibotaru, L F; Ceulemans, A

2005-10-06

An ab initio multiconfigurational approach has been used to calculate the ligand-field spectrum and magnetic properties of the title cyano-bridged dinuclear molybdenum complex. The rather large magnetic coupling parameter J for a single cyano bridge, as derived experimentally for this complex by susceptibility measurements, is confirmed to a high degree of accuracy by our CASPT2 calculations. Its electronic structure is rationalized in terms of spin-spin coupling between the two constituent hexacyano-monomolybdate complexes. An in-depth analysis on the basis of Anderson's kinetic exchange theory provides a qualitative picture of the calculated CASSCF antiferromagnetic ground-state eigenvector in the Mo dimer. Dynamic electron correlations as incorporated into our first-principles calculations by means of the CASPT2 method are essential to obtain quantitative agreement between theory and experiment.

Relativistic many-body theory of atomic structures

International Nuclear Information System (INIS)

Cheng, K.T.

1983-01-01

The main objective of this program is to improve our understanding of the effect of relativity and electron correlations on atomic processes. Current efforts include hyperfine structure (hfs) studies using the multiconfiguration Dirac-Fock (MCDF) technique. Atomic hfs are known to be sensitive to relativity and electron correlations, and provide important tests of relativistic atomic many-body theories. Preliminary results on the hfs of the 4f 12 3 H ground state of 68 Er 167 are shown and are in good agreement with experiment. This shows that the MCDF technique can be an efficient and powerful method for atomic hfs studies. Further tests of this method are in progress. We are also studying the absorption spectra for Xe-like ions in the region of 4d → nf, epsilonf transitions

7 CFR 65.170 - Ground lamb.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Ground lamb. 65.170 Section 65.170 Agriculture... OF BEEF, PORK, LAMB, CHICKEN, GOAT MEAT, PERISHABLE AGRICULTURAL COMMODITIES, MACADAMIA NUTS, PECANS, PEANUTS, AND GINSENG General Provisions Definitions § 65.170 Ground lamb. Ground lamb means comminuted...

7 CFR 65.165 - Ground goat.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Ground goat. 65.165 Section 65.165 Agriculture... OF BEEF, PORK, LAMB, CHICKEN, GOAT MEAT, PERISHABLE AGRICULTURAL COMMODITIES, MACADAMIA NUTS, PECANS, PEANUTS, AND GINSENG General Provisions Definitions § 65.165 Ground goat. Ground goat means comminuted...

Grounded Theory in Medical Education Research.

Science.gov (United States)

Tavakol, Mohsen; Torabi, Sima; Akbar Zeinaloo, Ali

2006-12-01

The grounded theory method provides a systematic way to generate theoretical constructs or concepts that illuminate psychosocial processes common to individual who have a similar experience of the phenomenon under investigation. There has been an increase in the number of published research reports that use the grounded theory method. However, there has been less medical education research, which is based on the grounded theory tradition. The purpose of this paper is to introduce basic tenants of qualitative research paradigm with specific reference to ground theory. The paper aims to encourage readers to think how they might possibly use the grounded theory method in medical education research and to apply such a method to their own areas of interest. The important features of a grounded theory as well as its implications for medical education research are explored. Data collection and analysis are also discussed. It seems to be reasonable to incorporate knowledge of this kind in medical education research.

30 CFR 77.801 - Grounding resistors.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding resistors. 77.801 Section 77.801 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH...-Voltage Distribution § 77.801 Grounding resistors. The grounding resistor, where required, shall be of the...

Ground states of a spin-boson model

International Nuclear Information System (INIS)

Amann, A.

1991-01-01

Phase transition with respect to ground states of a spin-boson Hamiltonian are investigated. The spin-boson model under discussion consists of one spin and infinitely many bosons with a dipole-type coupling. It is shown that the order parameter of the model vanishes with respect to arbitrary ground states if it vanishes with respect to ground states obtained as (biased) temperature to zero limits of thermic equilibrium states. The ground states of the latter special type have been investigated by H. Spohn. Spohn's respective phase diagrams are therefore valid for arbitrary ground states. Furthermore, disjointness of ground states in the broken symmetry regime is examined

Photodissociation dynamics in the first absorption band of pyrrole. I. Molecular Hamiltonian and the Herzberg-Teller absorption spectrum for the A12(π σ* ) ←X˜ 1 A1(π π ) transition

Science.gov (United States)

Picconi, David; Grebenshchikov, Sergy Yu.

2018-03-01

This paper opens a series in which the photochemistry of the two lowest πσ* states of pyrrole and their interaction with each other and with the ground electronic state X ˜ are studied using ab initio quantum mechanics. New 24-dimensional potential energy surfaces for the photodissociation of the N-H bond and the formation of the pyrrolyl radical are calculated using the multiconfigurational perturbation theory (CASPT2) for the electronic states X ˜ (π π ) , 11A2(πσ*), and 11B1(πσ*) and locally diabatized. In this paper, the ab initio calculations are described and the photodissociation in the state 11A2(πσ*) is analyzed. The excitation 11 A2←X ˜ is mediated by the coordinate dependent transition dipole moment functions constructed using the Herzberg-Teller expansion. Nuclear dynamics, including 6, 11, and 15 active degrees of freedom, are studied using the multi-configurational time-dependent Hartree method. The focus is on the frequency resolved absorption spectrum as well as on the dissociation time scales and the resonance lifetimes. Calculations are compared with available experimental data. An approximate convolution method is developed and validated, with which absorption spectra can be calculated and assigned in terms of vibrational quantum numbers. The method represents the total absorption spectrum as a convolution of the diffuse spectrum of the detaching H-atom and the Franck-Condon spectrum of the heteroaromatic ring. Convolution calculation requires a minimal quantum chemical input and is a promising tool for studying the πσ* photodissociation in model biochromophores.

Theoretical hyperfine structures of 19F i and 17O i

Science.gov (United States)

Aourir, Nouria; Nemouchi, Messaoud; Godefroid, Michel; Jönsson, Per

2018-03-01

Multiconfiguration Hartree-Fock (MCHF) and multiconfiguration Dirac-Hartree-Fock (MCDHF) calculations are performed for the 2 p5P2o , 2 p4(3P ) 3 s 4P , 2 p4(3P ) 3 s 2P , and 2 p4(3P ) 3 p 4So states of 19F i to determine their hyperfine constants. Several computing strategies are considered to investigate electron correlation and relativistic effects. High-order correlation contributions are included in MCHF calculations based on single and double multireference expansions. The largest components of the single reference MCHF wave functions are selected to define the multireference (MR) sets. In this scheme, relativistic corrections are evaluated in the Breit-Pauli approximation. A similar strategy is used for the calculation of MCDHF relativistic wave functions and hyperfine parameters. While correlation and relativistic corrections are found to be rather small for the ground state, we highlight large relativistic effects on the hyperfine constant A3 /2 of 2 p4(3P ) 3 p 4So and, to a lesser extent, on A1 /2 of 2 p4(3P ) 3 s 4P . As expected for such a light system, electron correlation effects dominate over relativity in the calculation of the hyperfine interaction of all other levels considered. We also revisit the hyperfine constants of 2 p3(4S ) 3 s S5o and 2 p3(4S ) 3 p 5P in 17O using similar strategies. The results are found to be in excellent agreement with experiment.

Modelling man-made ground to link the above- and below- ground urban domains

NARCIS (Netherlands)

Schokker, J.

2017-01-01

This report describes the results of STSM TU1206-36204. During a visit to GEUS (DK) between 23 and 27 January 2017, Jeroen Schokker (TNO-GSN, NL) has focussed on the modelling of man-made ground as a linking pin between the above- and below-ground urban domains. Key results include: • Man-made

Identification of resonant earthquake ground motion

Indian Academy of Sciences (India)

Resonant ground motion has been observed in earthquake records measured at several parts of the world. This class of ground motion is characterized by its energy being contained in a narrow frequency band. This paper develops measures to quantify the frequency content of the ground motion using the entropy ...

Ground Water and Climate Change

Science.gov (United States)

Taylor, Richard G.; Scanlon, Bridget; Doell, Petra; Rodell, Matt; van Beek, Rens; Wada, Yoshihide; Longuevergne, Laurent; Leblanc, Marc; Famiglietti, James S.; Edmunds, Mike;

Ground-water monitoring under RCRA

International Nuclear Information System (INIS)

Coalgate, J.

1993-11-01

In developing a regulatory strategy for the disposal of hazardous waste under the Resource Conservation and Recovery Act (RCRA), protection of ground-water resources was the primary goal of the Environmental Protection Agency (EPA). EPA's ground-water protection strategy seeks to minimize the potential for hazardous wastes and hazardous constituents in waste placed in land disposel units to migrate into the environment. This is achieved through liquids management (limiting the placement of liquid wastes in or on the land, requiring the use of liners beneath waste, installing leachate collection systems and run-on and run-off controls, and covering wastes at closure). Ground-water monitoring serves to detect any failure in EPA's liquids management strategy so that ground-water contamination can be detected and addressed as soon as possible

Using periodicity to mitigate ground vibration

DEFF Research Database (Denmark)

Andersen, Lars Vabbersgaard

2015-01-01

Introduction of trenches, barriers and wave impeding blocks on the transmission path between a source and receiver can be used for mitigation of ground vibration. However, to be effective a barrier must have a depth of about one wavelength of the waves to be mitigated. Hence, while great reductions......: A soil with periodic stiffening (ground improvement) and a ground with periodic changes in the surface elevation obtained by artificial landscaping. By means of a two-dimensional finite-element model, the stiffness and mass matrices are determined for a single cell of the ground with horizonal...

Citrus-orchard ground harbours a diverse, well-established and abundant ground-dwelling spider fauna

Energy Technology Data Exchange (ETDEWEB)

Monzo, C.; Molla, O.; Vanaclocha, P.; Monton, H.; Melic, A.; Castanera, P.; Urbaneja, A.

2011-07-01

Ground-dwelling spider assemblages comprise one of the most representative predatory groups to be found in many crops. There is some evidence of the role that ground-dwelling spiders play in controlling certain citrus pests; however, there are almost no studies about the abundance and composition of this predatory group in citrus orchards. A three-year survey conducted using pitfall traps in three citrus orchards in Eastern Spain yielded more than five-thousand ground-dwelling spiders belonging to more than 50 species and 20 families. Wandering families such as Lycosidae, Gnaphosidae and Zodariidae were the most numerous in terms of captures. The generalist predator Pardosa cribata Simon (Araneae: Lycosidae) was the most common species, representing a quarter of all captures, followed by Zodarion cesari Pekar. (Araneae: Zodariidae) and Trachyzelotes fuscipes (Koch) (Araneae: Gnaphosidae). Spiders were active throughout the year with a peak population in summer. The species abundance data for the three spider assemblages sampled fitted a log normal statistical model which is consistent with a well-established community. The presence of a cover crop provided higher abundance of alternative prey and consequently higher abundance and diversity of ground-dwelling spiders. This work demonstrates that the citrus-orchard ground harbours a diverse and abundant ground-dwelling spider fauna, which is also active throughout the year. A challenge for future studies will be to establish conservation management strategies for these predators, that will improve biological control of those citrus pests that inhabit or spend part of their life cycle on the orchard floor. (Author) 49 refs.

Hydrogeology, simulated ground-water flow, and ground-water quality, Wright-Patterson Air Force Base, Ohio

Science.gov (United States)

Dumouchelle, D.H.; Schalk, C.W.; Rowe, G.L.; De Roche, J.T.

1993-01-01

Ground water is the primary source of water in the Wright-Patterson Air Force Base area. The aquifer consists of glacial sands and gravels that fill a buried bedrock-valley system. Consolidated rocks in the area consist of poorly permeable Ordovician shale of the Richmondian stage, in the upland areas, the Brassfield Limestone of Silurian age. The valleys are filled with glacial sediments of Wisconsinan age consisting of clay-rich tills and coarse-grained outwash deposits. Estimates of hydraulic conductivity of the shales based on results of displacement/recovery tests range from 0.0016 to 12 feet per day; estimates for the glacial sediments range from less than 1 foot per day to more than 1,000 feet per day. Ground water flow from the uplands towards the valleys and the major rivers in the region, the Great Miami and the Mad Rivers. Hydraulic-head data indicate that ground water flows between the bedrock and unconsolidated deposits. Data from a gain/loss study of the Mad River System and hydrographs from nearby wells reveal that the reach of the river next to Wright-Patterson Air Force Base is a ground-water discharge area. A steady-state, three-dimensional ground-water-flow model was developed to simulate ground-water flow in the region. The model contains three layers and encompasses about 100 square miles centered on Wright-Patterson Air Force Base. Ground water enters the modeled area primarily by river leakage and underflow at the model boundary. Ground water exits the modeled area primarily by flow through the valleys at the model boundaries and through production wells. A model sensitivity analysis involving systematic changes in values of hydrologic parameters in the model indicates that the model is most sensitive to decreases in riverbed conductance and vertical conductance between the upper two layers. The analysis also indicates that the contribution of water to the buried-valley aquifer from the bedrock that forms the valley walls is about 2 to 4

Ground and excited states of the [Fe(H2O)6]2+ and [Fe(H2O)6]3+ clusters: Insight into the electronic structure of the [Fe(H2O)6]2+ – [Fe(H2O)6]3+ complex

Energy Technology Data Exchange (ETDEWEB)

Miliordos, Evangelos; Xantheas, Sotiris S.

2015-04-14

We report the ground and low lying electronically excited states of the [Fe(H2O)6]2+ and [Fe(H2O)6]3+ clusters using multi-configuration electronic structure theory. In particular, we have constructed the Potential Energy Curves (PECs) with respect to the iron-oxygen distance when removing all water ligands at the same time from the cluster minima and established their correlation to the long range dissociation channels. Due to the fact that both the second and third ionization potentials of iron are larger than the one for water, the ground state products asymptotically correlate with dissociation channels that are repulsive in nature at large separations as they contain at least one H2O+ fragment and a positive metal center. The most stable equilibrium structures emanate – via intersections and/or avoided crossings – from the channels consisting of the lowest electronic states of Fe2+(5D; 3d6) or Fe3+(6S; 3d5) and six neutral water molecules. Upon hydration, the ground state of Fe2+(H2O)6 is a triply (5Tg) degenerate one with the doubly (5Eg) degenerate state lying slightly higher in energy. Similarly, Fe3+(H2O)6 has a ground state of 6Ag symmetry under Th symmetry. We furthermore examine a multitude of electronically excited states of many possible spin multiplicities, and report the optimized geometries for several selected states. The PECs for those cases are characterized by a high density of states. Focusing on the ground and the first few excited states of the [Fe(H2O)6]2+ and [Fe(H2O)6]3+ clusters, we studied their mutual interaction in the gas phase. We obtained the optimal geometries of the Fe2+(H2O)6 – Fe3+(H2O)6 gas phase complex for different Fe–Fe distances. For distances shorter than 6.0 Å, the water molecules in the respective first solvation shells located between the two metal centers were found to interact via weak hydrogen bonds. We examined a total of ten electronic states for this complex, including those corresponding to the

Efektivitas Instagram Common Grounds

OpenAIRE

Wifalin, Michelle

2016-01-01

Efektivitas Instagram Common Grounds merupakan rumusan masalah yang diambil dalam penelitian ini. Efektivitas Instagram diukur menggunakan Customer Response Index (CRI), dimana responden diukur dalam berbagai tingkatan, mulai dari awareness, comprehend, interest, intentions dan action. Tingkatan respons inilah yang digunakan untuk mengukur efektivitas Instagram Common Grounds. Teori-teori yang digunakan untuk mendukung penelitian ini yaitu teori marketing Public Relations, teori iklan, efekti...

Ground-based photo monitoring

Science.gov (United States)

Frederick C. Hall

2000-01-01

Ground-based photo monitoring is repeat photography using ground-based cameras to document change in vegetation or soil. Assume those installing the photo location will not be the ones re-photographing it. This requires a protocol that includes: (1) a map to locate the monitoring area, (2) another map diagramming the photographic layout, (3) type and make of film such...

Management of ground water using isotope techniques

International Nuclear Information System (INIS)

Romani, Saleem

2004-01-01

Ground water play a major role in national economy and sustenance of life and environment. Prevalent water crisis in India includes falling water table, water quality deterioration, water logging and salinity. Keeping in view the increasing thrust on groundwater resources and the present scenario of availability vis-a vis demand there is a need to reorient our approach to ground water management. The various ground water management options require proper understanding of ground water flow system. Isotopes are increasingly being applied in hydrogeological investigations as a supplementary tool for assessment of aquifer flow and transport characteristics. Isotope techniques coupled with conventional hydrogeological and hydrochemical methods can bring in greater accuracy in the conceptualization of hydrogeological control mechanism. The use of isotope techniques in following areas can certainly be of immense help in implementing various ground water management options in an efficient manner. viz.Interaction between the surface water - groundwater systems to plan conjunctive use of surface and ground water. Establishing hydraulic interconnections between the aquifers in a multi aquifer system. Depth of circulation of water and dating of ground water. Demarcating ground water recharge and discharge areas. Plan ground water development in coastal aquifers to avoid sea water ingress. Development of flood plain aquifer. (author)

Navigating the grounded theory terrain. Part 1.

Science.gov (United States)

Hunter, Andrew; Murphy, Kathy; Grealish, Annmarie; Casey, Dympna; Keady, John

2011-01-01

The decision to use grounded theory is not an easy one and this article aims to illustrate and explore the methodological complexity and decision-making process. It explores the decision making of one researcher in the first two years of a grounded theory PhD study looking at the psychosocial training needs of nurses and healthcare assistants working with people with dementia in residential care. It aims to map out three different approaches to grounded theory: classic, Straussian and constructivist. In nursing research, grounded theory is often referred to but it is not always well understood. This confusion is due in part to the history of grounded theory methodology, which is one of development and divergent approaches. Common elements across grounded theory approaches are briefly outlined, along with the key differences of the divergent approaches. Methodological literature pertaining to the three chosen grounded theory approaches is considered and presented to illustrate the options and support the choice made. The process of deciding on classical grounded theory as the version best suited to this research is presented. The methodological and personal factors that directed the decision are outlined. The relative strengths of Straussian and constructivist grounded theories are reviewed. All three grounded theory approaches considered offer the researcher a structured, rigorous methodology, but researchers need to understand their choices and make those choices based on a range of methodological and personal factors. In the second article, the final methodological decision will be outlined and its research application described.

Principle and Design of a Single-phase Inverter-Based Grounding System for Neutral-to-ground Voltage Compensation in Distribution Networks

DEFF Research Database (Denmark)

Wang, Wen; Yan, Lingjie; Zeng, Xiangjun

2017-01-01

Neutral-to-ground overvoltage may occur in non-effectively grounded power systems because of the distributed parameters asymmetry and resonance between Petersen coil and distributed capacitances. Thus, the constraint of neutral-to-ground voltage is critical for the safety of distribution networks....... In this paper, an active grounding system based on single-phase inverter and its control parameter design method is proposed to achieve this objective. Relationship between its output current and neutral-to-ground voltage is derived to explain the principle of neutral-to-ground voltage compensation. Then...

Bonding and structure of copper nitrenes.

Science.gov (United States)

Cundari, Thomas R; Dinescu, Adriana; Kazi, Abul B

2008-11-03

Copper nitrenes are of interest as intermediates in the catalytic aziridination of olefins and the amination of C-H bonds. However, despite advances in the isolation and study of late-transition-metal multiply bonded complexes, a bona fide structurally characterized example of a terminal copper nitrene has, to our knowledge, not been reported. In anticipation of such a report, terminal copper nitrenes are studied from a computational perspective. The nitrene complexes studied here are of the form (beta-diketiminate)Cu(NPh). Density functional theory (DFT), complete active space self-consistent-field (CASSCF) electronic structure techniques, and hybrid quantum mechanical/molecular mechanical (QM/MM) methods are employed to study such species. While DFT methods indicate that a triplet (S = 1) is the ground state, CASSCF calculations indicate that a singlet (S = 0) is the ground state, with only a small energy gap between the singlet and triplet. Moreover, the ground-state (open-shell) singlet copper nitrene is found to be highly multiconfigurational (i.e., biradical) and to possess a bent geometry about the nitrene nitrogen, contrasting with the linear nitrene geometry of the triplet copper nitrenes. CASSCF calculations also reveal the existence of a closed-shell singlet state with some degree of multiple bonding character for the copper-nitrene bond.

Management Research and Grounded Theory: A review of grounded theorybuilding approach in organisational and management research.

Directory of Open Access Journals (Sweden)

Graham J.J. Kenealy, Ph.D.

2008-06-01

Full Text Available Grounded theory is a systematic methodology for the collection and analysis of data which was discovered by Glaser and Strauss in the 1960’s. The discovery of this method was first presented to the academic community in their book ‘The Discovery of Grounded Theory’ (1967 which still remains a primary point of reference for those undertaking qualitative research and grounded theory in particular. This powerful research method has become very popular in some research domains; whilst increasing in popularity it is still less prevalent in the field of organisational and management research particularly in its original form. This self reflexive paper sets out to explore the possibilities for this imbalance which takes the discussion onto the areas of methodological adaptation and training. It also enters the debate about access to research subjects and provides a succinct argument supporting the notion that grounded theory should simply be viewed as a method that develops empirically grounded conceptual theory.

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

Science.gov (United States)

Belcher, Wayne R.

2004-01-01

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

Figure-ground segmentation can occur without attention.

Science.gov (United States)

Kimchi, Ruth; Peterson, Mary A

2008-07-01

The question of whether or not figure-ground segmentation can occur without attention is unresolved. Early theorists assumed it can, but the evidence is scant and open to alternative interpretations. Recent research indicating that attention can influence figure-ground segmentation raises the question anew. We examined this issue by asking participants to perform a demanding change-detection task on a small matrix presented on a task-irrelevant scene of alternating regions organized into figures and grounds by convexity. Independently of any change in the matrix, the figure-ground organization of the scene changed or remained the same. Changes in scene organization produced congruency effects on target-change judgments, even though, when probed with surprise questions, participants could report neither the figure-ground status of the region on which the matrix appeared nor any change in that status. When attending to the scene, participants reported figure-ground status and changes to it highly accurately. These results clearly demonstrate that figure-ground segmentation can occur without focal attention.

Characteristics of near-field earthquake ground motion

International Nuclear Information System (INIS)

Kim, H. K.; Choi, I. G.; Jeon, Y. S.; Seo, J. M.

2002-01-01

The near-field ground motions exhibit special response characteristics that are different from those of ordinary ground motions in the velocity and displacement response. This study first examines the characteristics of near-field ground motion depending on fault directivity and fault normal and parallel component. And the response spectra of the near field ground motion are statistically processed, and are compared with the Regulatory Guide 1.60 spectrum that is present design spectrum of the nuclear power plant. The response spectrum of the near filed ground motions shows large spectral velocity and displacement in the low frequency range. The spectral accelerations of near field ground motion are greatly amplified in the high frequency range for the rock site motions, and in the low frequency range for the soil site motions. As a result, the near field ground motion effects should be considered in the seismic design and seismic safety evaluation of the nuclear power plant structures and equipment

Building Grounded Theory in Entrepreneurship Research

DEFF Research Database (Denmark)

Mäkelä, Markus; Turcan, Romeo V.

2007-01-01

In this chapter we describe the process of building of theory from data (Glaser and Strauss 1967; Strauss and Corbin 1998). We discuss current grounded theory in relation to research in entrepreneurship and point out directions and potential improvements for further research in this field....... The chapter has two goals. First, we wish to provide an explicit paradigmatic positioning of the grounded theory methodology, discussing the most relevant views of ontology and epistemology that can be used as alternative starting points for conducting grounded theory research. While the chapter introduces...... our approach to grounded theory, we acknowledge the existence of other approaches and try to locate our approach in relation to them. As an important part of this discussion, we take a stand on how to usefully define ‘grounded theory’ and ‘case study research’. Second, we seek to firmly link our...

Pollutant infiltration and ground water management

International Nuclear Information System (INIS)

1993-01-01

Following a short overview of hazard potentials for ground water in Germany, this book, which was compiled by the technical committee of DVWK on ground water use, discusses the natural scientific bases of pollutant movement to and in ground water. It points out whether and to what extent soil/ground water systems can be protected from harmful influences, and indicates relative strategies. Two zones are distinguished: the unsaturated zone, where local defence and remedial measures are frequently possible, and the saturated zone. From the protective function of geological systems, which is always pollutant-specific, criteria are derived for judging the systems generally, or at least regarding entire classes of pollutants. Finally, the impact of the infiltration of pollutants into ground water on its use as drinking water is pointed out and an estimate of the cost of remedial measures is given. (orig.) [de

Ground Motion Prediction Models for Caucasus Region

Science.gov (United States)

Jorjiashvili, Nato; Godoladze, Tea; Tvaradze, Nino; Tumanova, Nino

2016-04-01

Ground motion prediction models (GMPMs) relate ground motion intensity measures to variables describing earthquake source, path, and site effects. Estimation of expected ground motion is a fundamental earthquake hazard assessment. The most commonly used parameter for attenuation relation is peak ground acceleration or spectral acceleration because this parameter gives useful information for Seismic Hazard Assessment. Since 2003 development of Georgian Digital Seismic Network has started. In this study new GMP models are obtained based on new data from Georgian seismic network and also from neighboring countries. Estimation of models is obtained by classical, statistical way, regression analysis. In this study site ground conditions are additionally considered because the same earthquake recorded at the same distance may cause different damage according to ground conditions. Empirical ground-motion prediction models (GMPMs) require adjustment to make them appropriate for site-specific scenarios. However, the process of making such adjustments remains a challenge. This work presents a holistic framework for the development of a peak ground acceleration (PGA) or spectral acceleration (SA) GMPE that is easily adjustable to different seismological conditions and does not suffer from the practical problems associated with adjustments in the response spectral domain.

Ground water pollution through air pollutants

International Nuclear Information System (INIS)

Cichorowski, G.; Michel, B.; Versteegen, D.; Wettmann, R.

1989-01-01

The aim of the investigation is to determine the significance of air pollutants for ground water quality and ground water use. The report summarizes present knowledge and assesses statements with a view to potential ground water pollution from the air. In this context pollution paths, the spreading behaviour of pollutants, and 'cross points' with burden potentials from other pollutant sources are presented. (orig.) [de

Hanford site ground water protection management plan

International Nuclear Information System (INIS)

1994-10-01

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

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

High Throughput Determination of Plant Height, Ground Cover, and Above-Ground Biomass in Wheat with LiDAR.

Science.gov (United States)

Jimenez-Berni, Jose A; Deery, David M; Rozas-Larraondo, Pablo; Condon, Anthony Tony G; Rebetzke, Greg J; James, Richard A; Bovill, William D; Furbank, Robert T; Sirault, Xavier R R

2018-01-01

Crop improvement efforts are targeting increased above-ground biomass and radiation-use efficiency as drivers for greater yield. Early ground cover and canopy height contribute to biomass production, but manual measurements of these traits, and in particular above-ground biomass, are slow and labor-intensive, more so when made at multiple developmental stages. These constraints limit the ability to capture these data in a temporal fashion, hampering insights that could be gained from multi-dimensional data. Here we demonstrate the capacity of Light Detection and Ranging (LiDAR), mounted on a lightweight, mobile, ground-based platform, for rapid multi-temporal and non-destructive estimation of canopy height, ground cover and above-ground biomass. Field validation of LiDAR measurements is presented. For canopy height, strong relationships with LiDAR ( r 2 of 0.99 and root mean square error of 0.017 m) were obtained. Ground cover was estimated from LiDAR using two methodologies: red reflectance image and canopy height. In contrast to NDVI, LiDAR was not affected by saturation at high ground cover, and the comparison of both LiDAR methodologies showed strong association ( r 2 = 0.92 and slope = 1.02) at ground cover above 0.8. For above-ground biomass, a dedicated field experiment was performed with destructive biomass sampled eight times across different developmental stages. Two methodologies are presented for the estimation of biomass from LiDAR: 3D voxel index (3DVI) and 3D profile index (3DPI). The parameters involved in the calculation of 3DVI and 3DPI were optimized for each sample event from tillering to maturity, as well as generalized for any developmental stage. Individual sample point predictions were strong while predictions across all eight sample events, provided the strongest association with biomass ( r 2 = 0.93 and r 2 = 0.92) for 3DPI and 3DVI, respectively. Given these results, we believe that application of this system will provide new

Hanford Site ground-water surveillance for 1989

International Nuclear Information System (INIS)

Evans, J.C.; Bryce, R.W.; Bates, D.J.; Kemner, M.L.

1990-06-01

This annual report of ground-water surveillance activities provides discussions and listings of results for ground-water monitoring at the Hanford Site during 1989. The Pacific Northwest Laboratory (PNL) assesses the impacts of Hanford operations on the environment for the US Department of Energy (DOE). The impact Hanford operations has on ground water is evaluated through the Hanford Site Ground-Water Surveillance program. Five hundred and sixty-seven wells were sampled during 1989 for Hanford ground-water monitoring activities. This report contains a listing of analytical results for calendar year (CY) 1989 for species of importance as potential contaminants. 30 refs., 29 figs,. 4 tabs

Research of grounding capacitive current of neutral non-grounding auxiliary system in nuclear power plants

International Nuclear Information System (INIS)

Yang Shan; Liu Li; Huang Xiaojing

2014-01-01

In the domestic and abroad standards, the grounding capacitive current limitation in the non-grounding electric auxiliary system is less than 10 A. Limiting capacitive current in the standard aims to speed up the arc extinguishing to reduce the duration of arc over-voltage, but not to prevent the arc producing, The arc over-voltage harm is related to the multiple, frequency and duration of the over-voltage. When the insulation vulnerabilities appear in the equipment, the arc over-voltage may result in insulation vulnerabilities of the electrical equipment breakdown, which leads to multiple, short-circuit accidents. The cable connector, accessory and electromotor winding are all insulation vulnerabilities. Setting the arc suppression coil which can counteract the grounding capacitive current makes the arc vanish quickly. Using the casting bus which remarkably reduces the ground capacitance of the electric transmission line makes the equipment safer. (authors)

Grounding Damage to Conventional Vessels

DEFF Research Database (Denmark)

Lützen, Marie; Simonsen, Bo Cerup

2003-01-01

The present paper is concerned with rational design of conventional vessels with regard to bottom damage generated in grounding accidents. The aim of the work described here is to improve the design basis, primarily through analysis of new statistical data for grounding damage. The current regula...

Procedures for ground-water investigations

International Nuclear Information System (INIS)

1992-12-01

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

Humic substances in ground waters

International Nuclear Information System (INIS)

Paxeus, N.; Allard, B.; Olofsson, U.; Bengtsson, M.

1986-01-01

The presence of naturally occurring complexing agents that may enhance the migration of disposed radionuclikes and thus facilitate their uptake by plantsis a problem associated with the underground disposal of radioactive wastes in bedrock. The main purpose of this work is to characterized humic substances from ground water and compare them with humic substances from surface water. The humic materials isolated from ground waters of a borehole in Fjaellveden (Sweden) were characterized by elemental and functional group analyses. Spectroscopic properties, molecular weight distributions as well as acid-base properties of the fulvic and humic fractions were also studied. The ground water humic substances were found to be quite similar in many respects (but not identical) to the Swedish surface water humics concentrated from the Goeta River but appeared to be quite different from the American ground water humics from Biscayne Florida Aquifer or Laramie Fox-Hills in Colorado. The physico-chemical properties of the isolated humic materials are discussed

Ground Loop Impedance of Long EHV Cable Lines

DEFF Research Database (Denmark)

Ohno, Teruo; Bak, Claus Leth; Sørensen, Thomas K.

2012-01-01

The distance protection scheme without communication is often applied to the backup protection of EHV cable lines. For a reliable operation of a ground distance relay, the ground loop impedance of EHV cable lines needs to have a linear relationship to the distance from the relay location...... to the fault location. The discontinuity of the ground loop impedance at cross-bonding points may have an ill effect on the reliable operation of the ground distance relay. However, the cause and parameters of the discontinuity and its effects on the ground distance relay protection have not been discussed...... in literature. Through the calculation of the ground loop impedance for cable lines, it has been found that, for long EHV cable lines, the reliable operation of the ground distance relay is possible with a typical relay setting. Effects of parameters, such as substation grounding, cable layouts...

Antenna characteristics and air-ground interface deembedding methods for stepped-frequency ground-penetrating radar measurements

DEFF Research Database (Denmark)

Karlsen, Brian; Larsen, Jan; Jakobsen, Kaj Bjarne

2000-01-01

The result from field-tests using a Stepped-Frequency Ground Penetrating Radar (SF-GPR) and promising antenna and air-ground deembedding methods for a SF-GPR is presented. A monostatic S-band rectangular waveguide antenna was used in the field-tests. The advantages of the SF-GPR, e.g., amplitude...... and phase information in the SF-GPR signal, is used to deembed the characteristics of the antenna. We propose a new air-to-ground interface deembedding technique based on Principal Component Analysis which enables enhancement of the SF-GPR signal from buried objects, e.g., anti-personal landmines...

Artificial ground motion compatible with specified peak ground displacement and target multi-damping response spectra

International Nuclear Information System (INIS)

Zhang Yushan; Zhao Fengxin

2010-01-01

With respect to the design ground motion of nuclear power plant (NPP), the Regular Guide 1.60 of the US not only defined the standard multi-damping response spectra, i.e. the RG1.60 spectra, but also definitely prescribed the peak ground displacement (PGD) value corresponding to the standard spectra. However, in the engineering practice of generating multi-damping-spectra-compatible artificial ground motion for the seismic design of NPP, the PGD value had been neglected. Addressing this issue, this paper proposed a synthesizing method which generates the artificial ground motion compatible with not only the target multi-damping response spectra but also the specified PGD value. Firstly, by the transfer formula between the power spectrum and the response spectrum, an initial uniformly modulated acceleration time history is synthesized by multiplying the stationary Gaussian process with the prescribed intensity envelope to simulate the amplitude-non-stationarity of earthquake ground motion. And then by superimposing a series of narrow-band time histories in the time domain, the initial time history is modified in the iterative manner to match the target PGD as well as the target multi-damping spectra with the pre-specified matching precisions. Numerical examples are provided to demonstrate the matching precisions of the proposed method to the target values.

Investigation of the relationship between ground and engineering ...

Indian Academy of Sciences (India)

In order to investigate possible ground motion amplification in earthquake resistant building design, relationship between the ground and engineering bedrock must be ensured. In order to provide this relation, structure, basic characteristics, and thickness of the ground are investigated. In this context, calculating ground ...

Closed-form critical earthquake response of elastic-plastic structures on compliant ground under near-fault ground motions

Directory of Open Access Journals (Sweden)

Kotaro eKojima

2016-01-01

Full Text Available The double impulse is introduced as a substitute of the fling-step near-fault ground motion. A closed-form solution of the elastic-plastic response of a structure on compliant (flexible ground by the ‘critical double impulse’ is derived for the first time based on the solution for the corresponding structure with fixed base. As in the case of fixed-base model, only the free-vibration appears under such double impulse and the energy approach plays an important role in the derivation of the closed-form solution of a complicated elastic-plastic response on compliant ground. It is remarkable that no iteration is needed in the derivation of the critical elastic-plastic response. It is shown via the closed-form expression that, in the case of a smaller input level of double impulse to the structural strength, as the ground stiffness becomes larger, the maximum plastic deformation becomes larger. On the other hand, in the case of a larger input level of double impulse to the structural strength, as the ground stiffness becomes smaller, the maximum plastic deformation becomes larger. The criticality and validity of the proposed theory are investigated through the comparison with the response analysis to the corresponding one-cycle sinusoidal input as a representative of the fling-step near-fault ground motion. The applicability of the proposed theory to actual recorded pulse-type ground motions is also discussed.

Ground Attenuation of Railroad Noise

DEFF Research Database (Denmark)

Makarewicz, R.; Rasmussen, Karsten Bo; Kokowski, P.

1996-01-01

The influence of ground effect on railroad noise is described using the concept of the peak A-weighted sound exposure level, and A-weighted sound exposure level. The train is modelled by a continuous line of incoherent point sources that have a cosine directivity. The ground effect is included...

49 CFR 234.213 - Grounds.

Science.gov (United States)

2010-10-01

... Maintenance Standards § 234.213 Grounds. Each circuit that affects the proper functioning of a highway-rail... in the circuit. This requirement does not apply to: circuits that include track rail; alternating current power distribution circuits that are grounded in the interest of safety; and common return wires...

Making sense of grounded theory in medical education.

Science.gov (United States)

Kennedy, Tara J T; Lingard, Lorelei A

2006-02-01

Grounded theory is a research methodology designed to develop, through collection and analysis of data that is primarily (but not exclusively) qualitative, a well-integrated set of concepts that provide a theoretical explanation of a social phenomenon. This paper aims to provide an introduction to key features of grounded theory methodology within the context of medical education research. In this paper we include a discussion of the origins of grounded theory, a description of key methodological processes, a comment on pitfalls encountered commonly in the application of grounded theory research, and a summary of the strengths of grounded theory methodology with illustrations from the medical education domain. The significant strengths of grounded theory that have resulted in its enduring prominence in qualitative research include its clearly articulated analytical process and its emphasis on the generation of pragmatic theory that is grounded in the data of experience. When applied properly and thoughtfully, grounded theory can address research questions of significant relevance to the domain of medical education.

49 CFR 229.97 - Grounding fuel tanks.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Grounding fuel tanks. 229.97 Section 229.97 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Equipment § 229.97 Grounding fuel tanks. Fuel tanks and related piping shall be electrically grounded. ...

Enhanced spatial resolution on figures versus grounds.

Science.gov (United States)

Hecht, Lauren N; Cosman, Joshua D; Vecera, Shaun P

2016-07-01

Much is known about the cues that determine figure-ground assignment, but less is known about the consequences of figure-ground assignment on later visual processing. Previous work has demonstrated that regions assigned figural status are subjectively more shape-like and salient than background regions. The increase in subjective salience of figural regions could be caused by a number of processes, one of which may be enhanced perceptual processing (e.g., an enhanced neural representation) of figures relative to grounds. We explored this hypothesis by having observers perform a perceptually demanding spatial resolution task in which targets appeared on either figure or ground regions. To rule out a purely attentional account of figural salience, observers discriminated targets on the basis of a region's color (red or green), which was equally likely to define the figure or the ground. The results of our experiments showed that targets appearing on figures were discriminated more accurately than those appearing in ground regions. In addition, targets appearing on figures were discriminated better than those presented in regions considered figurally neutral, but targets appearing within ground regions were discriminated more poorly than those appearing in figurally neutral regions. Taken together, our findings suggest that when two regions share a contour, regions assigned as figure are perceptually enhanced, whereas regions assigned as ground are perceptually suppressed.

Enhanced spatial resolution on figures versus grounds

Science.gov (United States)

Hecht, Lauren N.; Cosman, Joshua D.; Vecera, Shaun P.

2016-01-01

Much is known about the cues that determine figure-ground assignment, but less is known about the consequences of figure-ground assignment on later visual processing. Previous work has demonstrated that regions assigned figural status are subjectively more shape-like and salient than background regions. The increase in subjective salience of figural regions could be caused by a number of processes, one of which may be enhanced perceptual processing (e.g., an enhanced neural representation) of figures relative to grounds. We explored this hypothesis by having observers perform a perceptually demanding spatial resolution task in which targets appeared either on figure or ground regions. To rule out a purely attentional account of figural salience, observers discriminated targets on the basis of a region’s color (red or green), which was equally likely to define the figure or the ground. The results of our experiments show that targets appearing on figures were discriminated more accurately than those appearing in ground regions. In addition, targets appearing on figures were discriminated better than those presented in regions considered figurally neutral, but targets appearing within ground regions were discriminated more poorly than those appearing in figurally neutral regions. Taken together, our findings suggest that when two regions share a contour, regions assigned as figure are perceptually enhanced, whereas regions assigned as grounds are perceptually suppressed. PMID:27048441

Ground-atmosphere interactions at Gale

Science.gov (United States)

Renno, N. O.; Martinez, G.; Ramos, M.; Hallet, B.; Gómez, F. G.; Jun, I.; Fisk, M. R.; Gomez-Elvira, J.; Hamilton, V. E.; Mischna, M. A.; Sletten, R. S.; Martin-Torres, J.; De La Torre Juarez, M.; Vasavada, A. R.; Zorzano, M.

2013-12-01

We analyze variations in environmental parameters and regolith properties along Curiosity's track to determine the possible causes of an abrupt change in the thermal properties of the ground and the atmosphere observed around Sol 120, as the rover transitioned from an area of sandy soil (Rocknest) to an area of fractured bedrock terrain (Yellowknife). Curiosity is instrumented with the Rover Environmental Monitoring Station (REMS) and the Dynamic Albedo of Neutrons (DAN) sensors to measure the air temperature, the ground temperature, and the hydrogen content of the shallow subsurface along Curiosity's track. Analysis of the REMS data is used to estimate the regolith's heat budget. This analysis suggests that the abrupt decrease in the ground and atmosphere temperature and the difference between ground and air temperatures observed around Sol 120 is likely caused by an increase in the soil thermal inertia. The changes in thermal inertia have been known for some time so confirming this by the REMS package provides ground truthing. A new unexpected finding is that the regolith water content, as indicated by DAN's detection of hydrogen content, is higher in the Yellowknife soil. Another interesting finding at this site are the holes and other signs of recent geological activity in the area of fractured terrain that may reflect large volumetric variations and facilitate gas exchange between the ground and atmosphere. Near-surface volumetric changes in soil and bedrock could reflect changes in the volume of subsurface H2O, or in the partitioning of H2O among its three phases. Volume increases could also result from salt crystal growth in rock pores and soil pores associated with the adsorption of water vapor. Crystallization in pores is a significant weathering process on Earth; it could well be active on Mars. Salts also inhibits the exchange of moisture between the ground and the atmosphere, and cements the soils of arid places such as in the McMurdo Dry Valleys in

Infrasonic induced ground motions

Science.gov (United States)

Lin, Ting-Li

On January 28, 2004, the CERI seismic network recorded seismic signals generated by an unknown source. Our conclusion is that the acoustic waves were initiated by an explosive source near the ground surface. The meteorological temperature and effective sound speed profiles suggested existence of an efficient near-surface waveguide that allowed the acoustic disturbance to propagate to large distances. An explosion occurring in an area of forest and farms would have limited the number of eyewitnesses. Resolution of the source might be possible by experiment or by detailed analysis of the ground motion data. A seismo-acoustic array was built to investigate thunder-induced ground motions. Two thunder events with similar N-wave waveforms but different horizontal slownesses are chosen to evaluate the credibility of using thunder as a seismic source. These impulsive acoustic waves excited P and S reverberations in the near surface that depend on both the incident wave horizontal slowness and the velocity structure in the upper 30 meters. Nineteen thunder events were chosen to further investigate the seismo-acoustic coupling. The consistent incident slowness differences between acoustic pressure and ground motions suggest that ground reverberations were first initiated somewhat away from the array. Acoustic and seismic signals were used to generate the time-domain transfer function through the deconvolution technique. Possible non-linear interaction for acoustic propagation into the soil at the surface was observed. The reverse radial initial motions suggest a low Poisson's ratio for the near-surface layer. The acoustic-to-seismic transfer functions show a consistent reverberation series of the Rayleigh wave type, which has a systematic dispersion relation to incident slownesses inferred from the seismic ground velocity. Air-coupled Rayleigh wave dispersion was used to quantitatively constrain the near-surface site structure with constraints afforded by near-surface body

BUSTED BUTTE TEST FACILITY GROUND SUPPORT CONFIRMATION ANALYSIS

International Nuclear Information System (INIS)

Bonabian, S.

1998-01-01

The main purpose and objective of this analysis is to confirm the validity of the ground support design for Busted Butte Test Facility (BBTF). The highwall stability and adequacy of highwall and tunnel ground support is addressed in this analysis. The design of the BBTF including the ground support system was performed in a separate document (Reference 5.3). Both in situ and seismic loads are considered in the evaluation of the highwall and the tunnel ground support system. In this analysis only the ground support designed in Reference 5.3 is addressed. The additional ground support installed (still work in progress) by the constructor is not addressed in this analysis. This additional ground support was evaluated by the A/E during a site visit and its findings and recommendations are addressed in this analysis

Essential methodological considerations when using grounded theory.

Science.gov (United States)

Achora, Susan; Matua, Gerald Amandu

2016-07-01

To suggest important methodological considerations when using grounded theory. A research method widely used in nursing research is grounded theory, at the centre of which is theory construction. However, researchers still struggle with some of its methodological issues. Although grounded theory is widely used to study and explain issues in nursing practice, many researchers are still failing to adhere to its rigorous standards. Researchers should articulate the focus of their investigations - the substantive area of interest as well as the focal population. This should be followed by a succinct explanation of the strategies used to collect and analyse data, supported by clear coding processes. Finally, the resolution of the core issues, including the core category and related categories, should be explained to advance readers' understanding. Researchers should endeavour to understand the tenets of grounded theory. This enables 'neophytes' in particular to make methodological decisions that will improve their studies' rigour and fit with grounded theory. This paper complements the current dialogue on improving the understanding of grounded theory methodology in nursing research. The paper also suggests important procedural decisions researchers need to make to preserve their studies' scientific merit and fit with grounded theory.

Move of ground water

International Nuclear Information System (INIS)

Kimura, Shigehiko

1983-01-01

As a ground water flow which is difficult to explain by Darcy's theory, there is stagnant water in strata, which moves by pumping and leads to land subsidence. This is now a major problem in Japan. Such move on an extensive scale has been investigated in detail by means of 3 H such as from rainfall in addition to ordinary measurement. The move of ground water is divided broadly into that in an unsaturated stratum from ground surface to water-table and that in a saturated stratum below the water-table. The course of the analyses made so far by 3 H contained in water, and the future trend of its usage are described. A flow model of regarding water as plastic fluid and its flow as channel assembly may be available for some flow mechanism which is not possible to explain with Darcy's theory. (Mori, K.)

Typhoon-Induced Ground Deformation

Science.gov (United States)

Mouyen, M.; Canitano, A.; Chao, B. F.; Hsu, Y.-J.; Steer, P.; Longuevergne, L.; Boy, J.-P.

2017-11-01

Geodetic instruments now offer compelling sensitivity, allowing to investigate how solid Earth and surface processes interact. By combining surface air pressure data, nontidal sea level variations model, and rainfall data, we systematically analyze the volumetric deformation of the shallow crust at seven borehole strainmeters in Taiwan induced by 31 tropical cyclones (typhoons) that made landfall to the island from 2004 to 2013. The typhoon's signature consists in a ground dilatation due to air pressure drop, generally followed by a larger ground compression. We show that this compression phase can be mostly explained by the mass loading of rainwater that falls on the ground and concentrates in the valleys towards the strainmeter sensitivity zone. Further, our analysis shows that borehole strainmeters can help quantifying the amount of rainwater accumulating and flowing over a watershed during heavy rainfalls, which is a useful constraint for building hydrological models.

Relational grounding facilitates development of scientifically useful multiscale models

Directory of Open Access Journals (Sweden)

Lam Tai

2011-09-01

Full Text Available Abstract We review grounding issues that influence the scientific usefulness of any biomedical multiscale model (MSM. Groundings are the collection of units, dimensions, and/or objects to which a variable or model constituent refers. To date, models that primarily use continuous mathematics rely heavily on absolute grounding, whereas those that primarily use discrete software paradigms (e.g., object-oriented, agent-based, actor typically employ relational grounding. We review grounding issues and identify strategies to address them. We maintain that grounding issues should be addressed at the start of any MSM project and should be reevaluated throughout the model development process. We make the following points. Grounding decisions influence model flexibility, adaptability, and thus reusability. Grounding choices should be influenced by measures, uncertainty, system information, and the nature of available validation data. Absolute grounding complicates the process of combining models to form larger models unless all are grounded absolutely. Relational grounding facilitates referent knowledge embodiment within computational mechanisms but requires separate model-to-referent mappings. Absolute grounding can simplify integration by forcing common units and, hence, a common integration target, but context change may require model reengineering. Relational grounding enables synthesis of large, composite (multi-module models that can be robust to context changes. Because biological components have varying degrees of autonomy, corresponding components in MSMs need to do the same. Relational grounding facilitates achieving such autonomy. Biomimetic analogues designed to facilitate translational research and development must have long lifecycles. Exploring mechanisms of normal-to-disease transition requires model components that are grounded relationally. Multi-paradigm modeling requires both hyperspatial and relational grounding.

Deflection of electron beams by ground planes

International Nuclear Information System (INIS)

Fernsler, R.F.; Lampe, M.

1991-01-01

Analytic methods are used to determine the effect of a nearby ground plane on the trajectory of a relativistic electron beam passing through dense gas. The beam is shown to respond to the ground plane in one of two distinct modes, determined by beam current and energy. Low-power beams deflect from the ground plane and tear longitudinally. High-power beams do not deflect or tear but tilt, i.e., the beam axis is no longer parallel to the direction of propagation. This conclusion is reached by computing the net beam force as a superposition of the ''bare'' ground-plane forces, the shielding forces from the beam-generated plasma, the body coupling forces induced by beam tilt, and the force that arises as the beam separates from the plasma. Effects from electromagnetic retardation and ground resistivity are shown to be negligible in typical cases of interest, and the interaction between ground planes and other external forces is discussed as well

21 CFR 225.120 - Buildings and grounds.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Buildings and grounds. 225.120 Section 225.120... Buildings and grounds. Buildings used for production of medicated feed shall provide adequate space for... routine maintenance and cleaning of equipment. Buildings and grounds shall be constructed and maintained...

Grounded Theory in Medical Education Research

OpenAIRE

Tavakol, Mohsen; Torabi, Sima; Akbar Zeinaloo, Ali

2009-01-01

The grounded theory method provides a systematic way to generate theoretical constructs or concepts that illuminate psychosocial processes common to individual who have a similar expe­rience of the phenomenon under investigation. There has been an increase in the number of pub­lished research reports that use the grounded theory method. However, there has been less medical education research, which is based on the grounded theory tradition. The purpose of this paper is to introduce basic tena...

IMPROVED ALGORITHM FOR CALCULATING COMPLEX NON-EQUIPOTENTIAL GROUNDING DEVICES OF ELECTRICAL INSTALLATIONS TAKING INTO ACCOUNT CONDUCTIVITY OF NATURAL GROUNDINGS

Directory of Open Access Journals (Sweden)

K. A. Starkov

2017-08-01

Full Text Available Purpose. The method of natural concentrated groundings substitution by the set of electrodes taking them into account in the algorithm of electric characteristics calculation for complicated grounding connections of electric installation is offered. An equivalent model as a set of linear electrodes is chosen in accordance with two criteria: leakage resistance and potentials on the ground surface. Methodology. We have applied induced potential method and methods for computing branched electrical circuits with distributed parameters. Results. We have obtained the algorithm for calculating complex non-equipotential grounding connections, which makes it possible to obtain refined values of the potential distribution in the electric stations and substations with outdoor switchgear. Originality. For the first time, we have taking into account the conductivity of natural concentrated grounds by a set of vertical and horizontal electrodes based on equivalent electrical characteristics applied to a two-layer ground. Practical value. The using of the proposed calculation algorithm in the electric grids of JSC «Kharkivoblenergo» made it possible to determine the values of the potential distribution at short circuit in electrical substation taking into account the influence of the conductivity of natural concentrated groundings.

The Steksovo II burial ground

Directory of Open Access Journals (Sweden)

Martianov Vladimir N.

2014-12-01

Full Text Available The article is dedicated to the results of many-years’ (1990-2010 excavations on the ancient Mordovian Steksovo II burial ground site. The burial ground had functioned in the 3rd to 13th centuries AD. The investigations revealed hundreds of burials, which enabled the researchers to judge upon the wealth of material items found and the variety of burial rites of the population that had formed the burial ground. The 1st millennium AD is characterized by bi-ritualism, while inhumation is characteristic of the 11-13th-century period; horses’ burials were also discovered. The data of the burial ground make it possible to modify the concept of the stages in ancient Mordovians ethnogenesis. It is generally attributed to the Erzya Mordvins, but in early burials the combination of the Erzya and Moksha ancientries is traced. Complexes of the items of crucial importance for the chronology of the burial are discussed in the article with a representation of statistical data characterizing funeral rites and traditions.

The automated ground network system

Science.gov (United States)

Smith, Miles T.; Militch, Peter N.

1993-01-01

The primary goal of the Automated Ground Network System (AGNS) project is to reduce Ground Network (GN) station life-cycle costs. To accomplish this goal, the AGNS project will employ an object-oriented approach to develop a new infrastructure that will permit continuous application of new technologies and methodologies to the Ground Network's class of problems. The AGNS project is a Total Quality (TQ) project. Through use of an open collaborative development environment, developers and users will have equal input into the end-to-end design and development process. This will permit direct user input and feedback and will enable rapid prototyping for requirements clarification. This paper describes the AGNS objectives, operations concept, and proposed design.

Ground-water flow and ground- and surface-water interaction at the Weldon Spring quarry, St. Charles County, Missouri

International Nuclear Information System (INIS)

Imes, J.L.; Kleeschulte, M.J.

1997-01-01

Ground-water-level measurements to support remedial actions were made in 37 piezometers and 19 monitoring wells during a 19-month period to assess the potential for ground-water flow from an abandoned quarry to the nearby St. Charles County well field, which withdraws water from the base of the alluvial aquifer. From 1957 to 1966, low-level radioactive waste products from the Weldon Spring chemical plant were placed in the quarry a few hundred feet north of the Missouri River alluvial plain. Uranium-based contaminants subsequently were detected in alluvial ground water south of the quarry. During all but flood conditions, lateral ground-water flow in the bedrock from the quarry, as interpreted from water-table maps, generally is southwest toward Little Femme Osage Creek or south into the alluvial aquifer. After entering the alluvial aquifer, the ground water flows southeast to east toward a ground-water depression presumably produced by pumping at the St. Charles County well field. The depression position varies depending on the Missouri River stage and probably the number and location of active wells in the St. Charles County well field

Ground states of quantum spin systems

International Nuclear Information System (INIS)

Bratteli, Ola; Kishimoto, Akitaka; Robinson, D.W.

1978-07-01

The authors prove that ground states of quantum spin systems are characterized by a principle of minimum local energy and that translationally invariant ground states are characterized by the principle of minimum energy per unit volume

Reassessment of Ground-Water Recharge and Simulated Ground-Water Availability for the Hawi Area of North Kohala, Hawaii

Science.gov (United States)

Oki, Delwyn S.

2002-01-01

An estimate of ground-water availability in the Hawi area of north Kohala, Hawaii, is needed to determine whether ground-water resources are adequate to meet future demand within the area and other areas to the south. For the Hawi area, estimated average annual recharge from infiltration of rainfall, fog drip, and irrigation is 37.5 million gallons per day from a daily water budget. Low and high annual recharge estimates for the Hawi area that incorporate estimated uncertainty are 19.9 and 55.4 million gallons per day, respectively. The recharge estimates from this study are lower than the recharge of 68.4 million gallons per day previously estimated from a monthly water budget. Three ground-water models, using the low, intermediate, and high recharge estimates (19.9, 37.5, and 55.4 million gallons per day, respectively), were developed for the Hawi area to simulate ground-water levels and discharges for the 1990?s. To assess potential ground-water availability, the numerical ground-water flow models were used to simulate the response of the freshwater-lens system to withdrawals at rates in excess of the average 1990?s withdrawal rates. Because of uncertainty in the recharge estimate, estimates of ground-water availability also are uncertain. Results from numerical simulations indicate that for appropriate well sites, depths, and withdrawal rates (1) for the low recharge estimate (19.9 million gallons per day) it may be possible to develop an additional 10 million gallons per day of fresh ground water from the Hawi area and maintain a freshwater-lens thickness of 160 feet near the withdrawal sites, (2) for the intermediate recharge estimate (37.5 million gallons per day) it may be possible to develop an additional 15 million gallons per day of fresh ground water from the Hawi area and maintain a freshwater-lens thickness of 190 feet near the withdrawal sites, and (3) for the high recharge estimate (55.4 million gallons per day) it may be possible to develop at

46 CFR 120.376 - Grounded distribution systems (Neutral grounded).

Science.gov (United States)

2010-10-01

....376 Section 120.376 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS... distribution system having a neutral bus or conductor must have the neutral grounded. (c) The neutral or each...

River as a part of ground battlefield

Science.gov (United States)

Vračar, Miodrag S.; Pokrajac, Ivan; Okiljević, Predrag

2013-05-01

The rivers are in some circumstances part of the ground battlefield. Microseisms induced at the riverbed or ground at the river surrounding might be consequence of military activities (military ground transports, explosions, troop's activities, etc). Vibrations of those fluid-solid structures are modeled in terms of solid displacement and change of fluid pressure. This time varying fluid pressure in river, which originates from ground microseisms, is possible to detect with hydrophones. Therefore, hydroacoustic measurements in rivers enables detecting, identification and localization various types of military noisy activities at the ground as and those, which origin is in the river water (hydrodynamics of water flow, wind, waves, river vessels, etc). In this paper are presented river ambient noise measurements of the three great rivers: the Danube, the Sava and the Tisa, which flows in north part of Serbia in purpose to establish limits in detection of the ground vibrations in relatively wide frequency range from zero to 20 kHz. To confirm statement that the river is a part of ground battlefield, and that hydroacoustic noise is possible to use in detecting and analyzing ground microseisms induced by civil or military activities, some previous collected data of hydroacoustic noise measurement in the rivers are used. The data of the river ambient noise include noise induced by civil engineering activities, that ordinary take place in large cities, noise that produced ships and ambient noise of the river when human activities are significantly reduced. The poly spectral method was used in analysis such events.

Ground Motion Models for Future Linear Colliders

International Nuclear Information System (INIS)

Seryi, Andrei

2000-01-01

Optimization of the parameters of a future linear collider requires comprehensive models of ground motion. Both general models of ground motion and specific models of the particular site and local conditions are essential. Existing models are not completely adequate, either because they are too general, or because they omit important peculiarities of ground motion. The model considered in this paper is based on recent ground motion measurements performed at SLAC and at other accelerator laboratories, as well as on historical data. The issues to be studied for the models to become more predictive are also discussed

Measurement of ground motion in various sites

International Nuclear Information System (INIS)

Bialowons, W.; Amirikas, R.; Bertolini, A.; Kruecker, D.

2007-04-01

Ground vibrations may affect low emittance beam transport in linear colliders, Free Electron Lasers (FEL) and synchrotron radiation facilities. This paper is an overview of a study program to measure ground vibrations in various sites which can be used for site characterization in relation to accelerator design. Commercial broadband seismometers have been used to measure ground vibrations and the resultant database is available to the scientific community. The methodology employed is to use the same equipment and data analysis tools for ease of comparison. This database of ground vibrations taken in 19 sites around the world is first of its kind. (orig.)

The ground-fault detection system for DIII-D

International Nuclear Information System (INIS)

Scoville, J.T.; Petersen, P.I.

1987-10-01

This paper presents a discussion of the ground-fault detection systems on the DIII-D tokamak. The subsystems that must be monitored for an inadvertent ground include the toroidal and poloidal coil systems, the vacuum vessel, and the coil support structures. In general, one point of each coil is tied to coil/power supply ground through a current limiting resistor. For ground protection the current through this resistor is monitored using a dynamically feedback balanced Hall probe transducer from LEM Industries. When large inductive currents flow in closed loops near the tokamak, the result is undesirable magnetic error fields in the plasma region and noise generation on signal cables. Therefore, attention must be paid to avoid closed loops in the design of the coil and vessel support structure. For DIII-D a concept of dual insulating breaks and a single-point ground for all structure elements was used to satisfy this requirement. The integrity of the support structure is monitored by a system which continuously attempts to couple a variable frequency waveform onto these single-point grounds. The presence of an additional ground completes the circuit resulting in current flow. A Rogowski coil is then used to track the unwanted ground path in order to eliminate it. Details of the ground fault detection circuitry, and a description of its operation will be presented. 2 refs., 7 figs

Ground water

International Nuclear Information System (INIS)

Osmond, J.K.; Cowart, J.B.

1992-01-01

The great variations in concentrations and activity ratios of 234 U/ 238 U in ground waters and the features causing elemental and isotopic mobility in the hydrosphere are discussed. Fractionation processes and their application to hydrology and other environmental problems such as earthquake, groundwater and aquifer dating are described. (UK)

XML Flight/Ground Data Dictionary Management

Science.gov (United States)

Wright, Jesse; Wiklow, Colette

2007-01-01

A computer program generates Extensible Markup Language (XML) files that effect coupling between the command- and telemetry-handling software running aboard a spacecraft and the corresponding software running in ground support systems. The XML files are produced by use of information from the flight software and from flight-system engineering. The XML files are converted to legacy ground-system data formats for command and telemetry, transformed into Web-based and printed documentation, and used in developing new ground-system data-handling software. Previously, the information about telemetry and command was scattered in various paper documents that were not synchronized. The process of searching and reading the documents was time-consuming and introduced errors. In contrast, the XML files contain all of the information in one place. XML structures can evolve in such a manner as to enable the addition, to the XML files, of the metadata necessary to track the changes and the associated documentation. The use of this software has reduced the extent of manual operations in developing a ground data system, thereby saving considerable time and removing errors that previously arose in the translation and transcription of software information from the flight to the ground system.

Ibis ground calibration

International Nuclear Information System (INIS)

Bird, A.J.; Barlow, E.J.; Tikkanen, T.; Bazzano, A.; Del Santo, M.; Ubertini, P.; Blondel, C.; Laurent, P.; Lebrun, F.; Di Cocco, G.; Malaguti, E.; Gabriele, M.; La Rosa, G.; Segreto, A.; Quadrini, E.; Volkmer, R.

2003-01-01

We present an overview of results obtained from IBIS ground calibrations. The spectral and spatial characteristics of the detector planes and surrounding passive materials have been determined through a series of calibration campaigns. Measurements of pixel gain, energy resolution, detection uniformity, efficiency and imaging capability are presented. The key results obtained from the ground calibration have been: - optimization of the instrument tunable parameters, - determination of energy linearity for all detection modes, - determination of energy resolution as a function of energy through the range 20 keV - 3 MeV, - demonstration of imaging capability in each mode, - measurement of intrinsic detector non-uniformity and understanding of the effects of passive materials surrounding the detector plane, and - discovery (and closure) of various leakage paths through the passive shielding system

46 CFR 183.376 - Grounded distribution systems (neutral grounded).

Science.gov (United States)

2010-10-01

....376 Section 183.376 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the neutral... generator to ground before the generator is connected to the bus, except the neutral of an emergency power...

Mechanisms in wing-in-ground effect aerodynamics

Science.gov (United States)

Jones, Marvin Alan

An aircraft in low-level flight experiences a large increase in lift and a marked reduction in drag, compared with flight at altitude. This phenomenon is termed the 'wing-in-ground' effect. In these circumstances a region of high pressure is created beneath the aerofoil, and a pressure difference is set up between its upper and lower surfaces. A pressure difference is not permitted at the trailing edge and therefore a mechanism must exist which allows the pressures above and below to adjust themselves to produce a continuous pressure field in the wake. It is the study of this mechanism and its role in the aerodynamics of low-level flight that forms the basis of our investigation. We begin in Chapter 2 by considering the flow past a thin aero-foil moving at moderate distances from the ground, the typical ground clearance a being of order unity. The aforementioned mechanism is introduced and described in detail in the context of this inviscid problem. Chapter 3 considers the same flow for large and small ground clearances and in the later case shows that the flow solution beneath the aerofoil takes on a particularly simple form. In this case the lift is shown to increase as a-1. In Chapter 4 we focus on the flow past the trailing edge of an aerofoil moving even nearer the ground, with the ground just outside the boundary layer. We show that in this case our asymptotic theory for small a is consistent with a 'triple-deck' approach to the problem which incorporates ground effects via a new pressure-displacement law. The triple-deck ground-interference problem is stated and solved. In Chapter 5 we investigate the case where the aerofoil is so near the ground that the ground is inside the boundary layer. Here the moving ground interacts with the aerofoil in a fully viscous way and the non-linear boundary layer equations hold along the entire length of the aerofoil. Again a pressure difference at the trailing edge is not permitted and this produces upstream adjustment

Ground and Space Radar Volume Matching and Comparison Software

Science.gov (United States)

Morris, Kenneth; Schwaller, Mathew

2010-01-01

This software enables easy comparison of ground- and space-based radar observations. The software was initially designed to compare ground radar reflectivity from operational, ground based Sand C-band meteorological radars with comparable measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite s Precipitation Radar (PR) instrument. The software is also applicable to other ground-based and space-based radars. The ground and space radar volume matching and comparison software was developed in response to requirements defined by the Ground Validation System (GVS) of Goddard s Global Precipitation Mission (GPM) project. This software innovation is specifically concerned with simplifying the comparison of ground- and spacebased radar measurements for the purpose of GPM algorithm and data product validation. This software is unique in that it provides an operational environment to routinely create comparison products, and uses a direct geometric approach to derive common volumes of space- and ground-based radar data. In this approach, spatially coincident volumes are defined by the intersection of individual space-based Precipitation Radar rays with the each of the conical elevation sweeps of the ground radar. Thus, the resampled volume elements of the space and ground radar reflectivity can be directly compared to one another.

Correlation, Breit and quantum electrodynamics effects on energy level and transition properties of W54+ ion

International Nuclear Information System (INIS)

Ding, X.; Sun, R.; Dong, C.; Koike, F.; Kato, D.; Murakami, I.; Sakaue, H.A.

2017-01-01

The electron correlation effects and Breit interaction as well as Quantum Electro-Dynamics (QED) effects were expected to have important contribution to the energy level and transition properties of heavy highly charged ions. The study of W 54+ ion provide necessary reference data for the fusion plasma physics as tungsten was chosen to be used as the armour material of the divertor of the ITER project. The ground states [Ne]3s 2 3p 6 3d 2 and first excited states [Ne]3s 2 3p 5 3d 3 of W 54+ ion have been studied by using Multi-Configuration Dirac-Fock method with the implementation of Grasp2K package. A restricted active space method was employed to investigate the correlation contribution from different models. The Breit interaction and QED effects were taken into account in the relativistic configuration interaction calculation with the converged wavefunction. It is found that the correlation contribution from 3s and 3p orbital have important contribution to the energy level, transition wavelength and probability of the ground and the first excited state of W 54+ ion. (authors)

Dielectronic recombination data for dynamic finite-density plasmas. XV. The silicon isoelectronic sequence

Science.gov (United States)

Kaur, Jagjit; Gorczyca, T. W.; Badnell, N. R.

2018-02-01

Context. We aim to present a comprehensive theoretical investigation of dielectronic recombination (DR) of the silicon-like isoelectronic sequence and provide DR and radiative recombination (RR) data that can be used within a generalized collisional-radiative modelling framework. Aims: Total and final-state level-resolved DR and RR rate coefficients for the ground and metastable initial levels of 16 ions between P+ and Zn16+ are determined. Methods: We carried out multi-configurational Breit-Pauli DR calculations for silicon-like ions in the independent processes, isolated resonance, distorted wave approximation. Both Δnc = 0 and Δnc = 1 core excitations are included using LS and intermediate coupling schemes. Results: Results are presented for a selected number of ions and compared to all other existing theoretical and experimental data. The total dielectronic and radiative recombination rate coefficients for the ground state are presented in tabulated form for easy implementation into spectral modelling codes. These data can also be accessed from the Atomic Data and Analysis Structure (ADAS) OPEN-ADAS database. This work is a part of an assembly of a dielectronic recombination database for the modelling of dynamic finite-density plasmas.

Navigating Grounded Theory:A critical and reflective response to the challenges of using grounded theory in an education PhD

OpenAIRE

Nelson, James

2015-01-01

This paper offers a critical reflection upon the use of a grounded theory approach within a doctoral study. As well as providing an outline of grounded theory, it begins by noting the existence of some powerful critiques of a grounded theory approach, in particular around the key concepts of ‘theory’, ‘discovery’ and ‘ground’. It is argued that, in some cases, grounded theory struggles to counter these challenges, especially in its ‘purist’ forms. However, with reference to research carried o...

Ground water

International Nuclear Information System (INIS)

Osmond, J.K.; Cowart, J.B.

1982-01-01

The subject is discussed under the headings: background and theory (introduction; fractionation in the hydrosphere; mobility factors; radioisotope evolution and aquifer classification; aquifer disequilibria and geochemical fronts); case studies (introduction; (a) conservative, and (b) non-conservative, behaviour); ground water dating applications (general requirements; radon and helium; radium isotopes; uranium isotopes). (U.K.)

Modeled ground water age distributions

Science.gov (United States)

Woolfenden, Linda R.; Ginn, Timothy R.

2009-01-01

The age of ground water in any given sample is a distributed quantity representing distributed provenance (in space and time) of the water. Conventional analysis of tracers such as unstable isotopes or anthropogenic chemical species gives discrete or binary measures of the presence of water of a given age. Modeled ground water age distributions provide a continuous measure of contributions from different recharge sources to aquifers. A numerical solution of the ground water age equation of Ginn (1999) was tested both on a hypothetical simplified one-dimensional flow system and under real world conditions. Results from these simulations yield the first continuous distributions of ground water age using this model. Complete age distributions as a function of one and two space dimensions were obtained from both numerical experiments. Simulations in the test problem produced mean ages that were consistent with the expected value at the end of the model domain for all dispersivity values tested, although the mean ages for the two highest dispersivity values deviated slightly from the expected value. Mean ages in the dispersionless case also were consistent with the expected mean ages throughout the physical model domain. Simulations under real world conditions for three dispersivity values resulted in decreasing mean age with increasing dispersivity. This likely is a consequence of an edge effect. However, simulations for all three dispersivity values tested were mass balanced and stable demonstrating that the solution of the ground water age equation can provide estimates of water mass density distributions over age under real world conditions.

Evaluation of multimodal ground cues

DEFF Research Database (Denmark)

Nordahl, Rolf; Lecuyer, Anatole; Serafin, Stefania

2012-01-01

This chapter presents an array of results on the perception of ground surfaces via multiple sensory modalities,with special attention to non visual perceptual cues, notably those arising from audition and haptics, as well as interactions between them. It also reviews approaches to combining...... synthetic multimodal cues, from vision, haptics, and audition, in order to realize virtual experiences of walking on simulated ground surfaces or other features....

Ground water currents: Developments in innovative ground water treatment, March 1994

Energy Technology Data Exchange (ETDEWEB)

Eilers, R.

1994-03-01

;Contents: Hydrodynamic cavitation oxidation destroys organics; Biosparging documented in fuel remediation study; Surfactant flushing research to remove organic liquids from aquifers; and Compilation of Ground-Water Models (a book review).

Principle and Control Design of Active Ground-Fault Arc Suppression Device for Full Compensation of Ground Current

DEFF Research Database (Denmark)

Wang, Wen; Zeng, Xiangjun; Yan, Lingjie

2017-01-01

current into the neutral without any large-capacity reactors, and thus avoids the aforementioned overvoltage. It compensates all the active, reactive and harmonic components of the ground current to reliably extinguish the ground-fault arcs. A dual-loop voltage control method is proposed to realize arc...... suppression without capacitive current detection. Its time-based feature also brings the benefit of fast response on ground-fault arc suppression. The principle of full current compensation is analyzed, together with the controller design method of the proposed device. Experiment on a prototype was carried...

Method for analysis the complex grounding cables system

International Nuclear Information System (INIS)

Ackovski, R.; Acevski, N.

2002-01-01

A new iterative method for the analysis of the performances of the complex grounding systems (GS) in underground cable power networks with coated and/or uncoated metal sheathed cables is proposed in this paper. The analyzed grounding system consists of the grounding grid of a high voltage (HV) supplying transformer station (TS), middle voltage/low voltage (MV/LV) consumer TSs and arbitrary number of power cables, connecting them. The derived method takes into consideration the drops of voltage in the cable sheets and the mutual influence among all earthing electrodes, due to the resistive coupling through the soil. By means of the presented method it is possible to calculate the main grounding system performances, such as earth electrode potentials under short circuit fault to ground conditions, earth fault current distribution in the whole complex grounding system, step and touch voltages in the nearness of the earthing electrodes dissipating the fault current in the earth, impedances (resistances) to ground of all possible fault locations, apparent shield impedances to ground of all power cables, e.t.c. The proposed method is based on the admittance summation method [1] and is appropriately extended, so that it takes into account resistive coupling between the elements that the GS. (Author)

Grounded theory methodology - has it become a movement?

OpenAIRE

Berterö, Carina

2012-01-01

There is an ongoing debate regarding the nature of grounded theory, and an examination of many studies claiming to follow grounded theory indicates a wide range of approaches. In 1967 Glaser and Strauss’s ‘‘The Discovery of Grounded Theory; Strategies for Qualitative Research’’ was published and represented a breakthrough in qualitative research; it offered methodological consensus and systematic strategies for qualitative research practice. The defining characteristics of grounded theory inc...

Predicting Ground Illuminance

Science.gov (United States)

Lesniak, Michael V.; Tregoning, Brett D.; Hitchens, Alexandra E.

2015-01-01

Our Sun outputs 3.85 x 1026 W of radiation, of which roughly 37% is in the visible band. It is directly responsible for nearly all natural illuminance experienced on Earth's surface, either in the form of direct/refracted sunlight or in reflected light bouncing off the surfaces and/or atmospheres of our Moon and the visible planets. Ground illuminance, defined as the amount of visible light intercepting a unit area of surface (from all incident angles), varies over 7 orders of magnitude from day to night. It is highly dependent on well-modeled factors such as the relative positions of the Sun, Earth, and Moon. It is also dependent on less predictable factors such as local atmospheric conditions and weather.Several models have been proposed to predict ground illuminance, including Brown (1952) and Shapiro (1982, 1987). The Brown model is a set of empirical data collected from observation points around the world that has been reduced to a smooth fit of illuminance against a single variable, solar altitude. It provides limited applicability to the Moon and for cloudy conditions via multiplicative reduction factors. The Shapiro model is a theoretical model that treats the atmosphere as a three layer system of light reflectance and transmittance. It has different sets of reflectance and transmittance coefficients for various cloud types.In this paper we compare the models' predictions to ground illuminance data from an observing run at the White Sands missile range (data was obtained from the United Kingdom's Meteorology Office). Continuous illuminance readings were recorded under various cloud conditions, during both daytime and nighttime hours. We find that under clear skies, the Shapiro model tends to better fit the observations during daytime hours with typical discrepancies under 10%. Under cloudy skies, both models tend to poorly predict ground illuminance. However, the Shapiro model, with typical average daytime discrepancies of 25% or less in many cases

Hanford Site ground-water monitoring for 1994

International Nuclear Information System (INIS)

Dresel, P.E.; Thorne, P.D.; Luttrell, S.P.

1995-08-01

This report presents the results of the Ground-Water Surveillance Project monitoring for calendar year 1994 on the Hanford Site, Washington. Hanford Site operations from 1943 onward produced large quantities of radiologic and chemical waste that have impacted ground-water quality on the Site. Monitoring of water levels and ground-water chemistry is performed to track the extent of contamination and trends in contaminant concentrations. The 1994 monitoring was also designed to identify emerging ground-water quality problems. The information obtained is used to verify compliance with applicable environmental regulations and to evaluate remedial actions. Data from other monitoring and characterization programs were incorporated to provide an integrated assessment of Site ground-water quality. Additional characterization of the Site's geologic setting and hydrology was performed to support the interpretation of contaminant distributions. Numerical modeling of sitewide ground-water flow also supported the overall project goals. Water-level monitoring was performed to evaluate ground-water flow directions, to track changes in water levels, and to relate such changes to changes in site disposal practices. Water levels over most of the Hanford Site continued to decline between June 1993 and June 1994. These declines are part of the continued response to the cessation of discharge to U Pond and other disposal facilities. The low permeability in this area which enhanced mounding of waste-water discharge has also slowed the response to the reduction of disposal

Hanford Site ground-water monitoring for 1994

Energy Technology Data Exchange (ETDEWEB)

Dresel, P.E.; Thorne, P.D.; Luttrell, S.P. [and others

1995-08-01

This report presents the results of the Ground-Water Surveillance Project monitoring for calendar year 1994 on the Hanford Site, Washington. Hanford Site operations from 1943 onward produced large quantities of radiologic and chemical waste that have impacted ground-water quality on the Site. Monitoring of water levels and ground-water chemistry is performed to track the extent of contamination and trends in contaminant concentrations. The 1994 monitoring was also designed to identify emerging ground-water quality problems. The information obtained is used to verify compliance with applicable environmental regulations and to evaluate remedial actions. Data from other monitoring and characterization programs were incorporated to provide an integrated assessment of Site ground-water quality. Additional characterization of the Site`s geologic setting and hydrology was performed to support the interpretation of contaminant distributions. Numerical modeling of sitewide ground-water flow also supported the overall project goals. Water-level monitoring was performed to evaluate ground-water flow directions, to track changes in water levels, and to relate such changes to changes in site disposal practices. Water levels over most of the Hanford Site continued to decline between June 1993 and June 1994. These declines are part of the continued response to the cessation of discharge to U Pond and other disposal facilities. The low permeability in this area which enhanced mounding of waste-water discharge has also slowed the response to the reduction of disposal.

Navigating the grounded theory terrain. Part 2.

Science.gov (United States)

Hunter, Andrew; Murphy, Kathy; Grealish, Annmarie; Casey, Dympna; Keady, John

2011-01-01

In this paper, the choice of classic grounded theory will be discussed and justified in the context of the first author's PhD research. The methodological discussion takes place within the context of PhD research entitled: Development of a stakeholder-led framework for a structured education programme that will prepare nurses and healthcare assistants to deliver a psychosocial intervention for people with dementia. There is a lack of research and limited understanding of the effect of psychosocial interventions on people with dementia. The first author thought classic grounded theory a suitable research methodology to investigate as it is held to be ideal for areas of research where there is little understanding of the social processes at work. The literature relating to the practical application of classic grounded theory is illustrated using examples relating to four key grounded theory components: Theory development: using constant comparison and memoing, Methodological rigour, Emergence of a core category, Inclusion of self and engagement with participants. Following discussion of the choice and application of classic grounded theory, this paper explores the need for researchers to visit and understand the various grounded theory options. This paper argues that researchers new to grounded theory must be familiar with and understand the various options. The researchers will then be able to apply the methodologies they choose consistently and critically. Doing so will allow them to develop theory rigorously and they will ultimately be able to better defend their final methodological destinations.

Airfield Ground Safety

National Research Council Canada - National Science Library

Petrescu, Jon

2000-01-01

.... The system developed under AGS, called the Ground Safety Tracking and Reporting System, uses multisensor data fusion from in-pavement inductive loop sensors to address a critical problem affecting out nation's airports: runway incursions...

Ground Motion Prediction Equations Empowered by Stress Drop Measurement

Science.gov (United States)

Miyake, H.; Oth, A.

2015-12-01

Significant variation of stress drop is a crucial issue for ground motion prediction equations and probabilistic seismic hazard assessment, since only a few ground motion prediction equations take into account stress drop. In addition to average and sigma studies of stress drop and ground motion prediction equations (e.g., Cotton et al., 2013; Baltay and Hanks, 2014), we explore 1-to-1 relationship for each earthquake between stress drop and between-event residual of a ground motion prediction equation. We used the stress drop dataset of Oth (2013) for Japanese crustal earthquakes ranging 0.1 to 100 MPa and K-NET/KiK-net ground motion dataset against for several ground motion prediction equations with volcanic front treatment. Between-event residuals for ground accelerations and velocities are generally coincident with stress drop, as investigated by seismic intensity measures of Oth et al. (2015). Moreover, we found faster attenuation of ground acceleration and velocities for large stress drop events for the similar fault distance range and focal depth. It may suggest an alternative parameterization of stress drop to control attenuation distance rate for ground motion prediction equations. We also investigate 1-to-1 relationship and sigma for regional/national-scale stress drop variation and current national-scale ground motion equations.

Ground-Water Protection and Monitoring Program

Energy Technology Data Exchange (ETDEWEB)

Dresel, P.E.

1995-06-01

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

Ground-Water Protection and Monitoring Program

International Nuclear Information System (INIS)

Dresel, P.E.

1995-01-01

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

Ground motion effects

Energy Technology Data Exchange (ETDEWEB)

Blume, J A [John A. Blume and Associates, San Francisco, CA (United States)

1969-07-01

Ground motion caused by natural earthquakes or by nuclear explosion causes buildings and other structures to respond in such manner as possibly to have high unit stresses and to be subject to damage or-in some cases-collapse. Even minor damage may constitute a hazard to persons within or adjacent to buildings. The risk of damage may well be the governing restraint on the uses of nuclear energy for peaceful purposes. Theory is advanced regarding structural-dynamic response but real buildings and structures are complex, highly variable, and often difficult to model realistically. This paper discusses the state of knowledge, the art of damage prediction and safety precautions, and shows ground motion effects from explosions of underground nuclear devices in the continental United States including events Salmon, Gasbuggy, Boxcar, Faultless and Benham. (author)

Ground motion effects

International Nuclear Information System (INIS)

Blume, J.A.

1969-01-01

Ground motion caused by natural earthquakes or by nuclear explosion causes buildings and other structures to respond in such manner as possibly to have high unit stresses and to be subject to damage or-in some cases-collapse. Even minor damage may constitute a hazard to persons within or adjacent to buildings. The risk of damage may well be the governing restraint on the uses of nuclear energy for peaceful purposes. Theory is advanced regarding structural-dynamic response but real buildings and structures are complex, highly variable, and often difficult to model realistically. This paper discusses the state of knowledge, the art of damage prediction and safety precautions, and shows ground motion effects from explosions of underground nuclear devices in the continental United States including events Salmon, Gasbuggy, Boxcar, Faultless and Benham. (author)

Advanced Testing Method for Ground Thermal Conductivity

Energy Technology Data Exchange (ETDEWEB)

Liu, Xiaobing [ORNL; Clemenzi, Rick [Geothermal Design Center Inc.; Liu, Su [University of Tennessee (UT)

2017-04-01

A new method is developed that can quickly and more accurately determine the effective ground thermal conductivity (GTC) based on thermal response test (TRT) results. Ground thermal conductivity is an important parameter for sizing ground heat exchangers (GHEXs) used by geothermal heat pump systems. The conventional GTC test method usually requires a TRT for 48 hours with a very stable electric power supply throughout the entire test. In contrast, the new method reduces the required test time by 40%–60% or more, and it can determine GTC even with an unstable or intermittent power supply. Consequently, it can significantly reduce the cost of GTC testing and increase its use, which will enable optimal design of geothermal heat pump systems. Further, this new method provides more information about the thermal properties of the GHEX and the ground than previous techniques. It can verify the installation quality of GHEXs and has the potential, if developed, to characterize the heterogeneous thermal properties of the ground formation surrounding the GHEXs.

Figure-ground mechanisms provide structure for selective attention

OpenAIRE

Qiu, Fangtu T.; Sugihara, Tadashi; von der Heydt, Rüdiger

2007-01-01

Attention depends on figure-ground organization: figures draw attention, while shapes of the ground tend to be ignored. Recent research has demonstrated mechanisms of figure-ground organization in the visual cortex, but how they relate to the attention process remains unclear. Here we show that the influences of figure-ground organization and volitional (top-down) attention converge in single neurons of area V2. While assignment of border ownership was found for attended as well as for ignore...

Grounded meets floating

Science.gov (United States)

Walker, Ryan T.

2018-04-01

A comprehensive assessment of grounding-line migration rates around Antarctica, covering a third of the coast, suggests retreat in considerable portions of the continent, beyond the rates expected from adjustment following the Last Glacial Maximum.

Characterization of the effects of borehole configuration and interference with long term ground temperature modelling of ground source heat pumps

International Nuclear Information System (INIS)

Law, Ying Lam E.; Dworkin, Seth B.

2016-01-01

Highlights: • Long term ground temperature response is explored using finite element methods. • Simulation method is validated against experimental and analytical data. • Temperature changes at a fast rate in the first few years and slows down gradually. • ASHRAE recommended separation distances are not always sufficient. • Thermal accumulation occurs at the centre of borehole field. - Abstract: Ground source heat pumps (GSHPs) are an environmentally friendly alternative to conventional heating and cooling systems because of their high efficiency and low greenhouse gas emissions. The ground acts as a heat sink/source for the excess/required heat inside a building for cooling and heating modes, respectively. However, imbalance in heating and cooling needs can change ground temperature over the operating duration. This increase/decrease in ground temperature lowers system efficiency and causes the ground to foul—failing to accept or provide more heat. In order to ensure that GSHPs can operate to their designed conditions, thermal modelling is required to simulate the ground temperature during system operation. In addition, the borehole field layout can have a major impact on ground temperature. In this study, four buildings were studied—a hospital, fast-food restaurant, residence, and school, each with varying borehole configurations. Boreholes were modelled in a soil volume using finite-element methods and heating and cooling fluxes were applied to the borehole walls to simulate the GSHP operation. 20 years of operation were modelled for each building for 2 × 2, 4 × 4, and 2 × 8 borehole configurations. Results indicate that the borehole separation distance of 6 m, recommended by ASHRAE, is not always sufficient to prevent borehole thermal interactions. Benefits of using a 2 × 8 configuration as opposed to a 4 × 4 configuration, which can be observed because of the larger perimeter it provides for heat to dissipate to surrounding soil were

30 CFR 75.801 - Grounding resistors.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding resistors. 75.801 Section 75.801 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.801 Grounding...

Tethered Pyrotechnic Apparatus for Acquiring a Ground Sample

Science.gov (United States)

Jones, Jack; Zimmerman, Wayne; Wu, Jiunn Jenq; Badescu, Mircea; Sherrit, Stewart

2009-01-01

A proposed alternative design for the balloon-borne ground-sampling system described in the immediately preceding article would not rely on free fall to drive a harpoonlike sample-collecting device into the ground. Instead, the harpoon-like sample-collecting device would be a pyrotechnically driven, tethered projectile. The apparatus would include a tripod that would be tethered to the gondola. A gun for shooting the projectile into the ground would be mounted at the apex of the tripod. The gun would include an electronic trigger circuit, a chamber at the breech end containing a pyrotechnic charge, and a barrel. A sabot would be placed in the barrel just below the pyrotechnic charge, and the tethered projectile would be placed in the barrel just below the sabot. The tripod feet would be equipped with contact sensors connected to the trigger circuit. In operation, the tripod would be lowered to the ground on its tether. Once contact with the ground was detected by the sensors on all three tripod feet, the trigger circuit would fire the pyrotechnic charge to drive the projectile into the ground. (Requiring contact among all three tripod feet and the ground would ensure that the projectile would be fired into the ground, rather than up toward the gondola or the balloon.) The tethered projectile would then be reeled back up to the gondola for analysis of the sample.

Formation keeping of unmanned ground vehicles

Directory of Open Access Journals (Sweden)

Muangmin Kamonwan

2017-01-01

Full Text Available Controlling motions of an unmanned ground vehicle becomes more popular in real world practices. Its application is useful for household chores, military services, medical purposes, and industrial revolutions, etc. An analysis of motions by using the Fundamental Equations of Constrained Motion (FECM is one effective tool to determine the motions. Its conceptualization is done in three-step procedure as follows: (I Determining an unconstrained motion (II Assigning constraint equations and (III Computing a constrained motion. The equations of motion obtained are expressed as liner functions of acceleration. Then other kinematical information of the unmanned ground vehicles can be obtained by integration its acceleration. In this work, the FECM is used as a tool to analyze motions of a group of unmanned ground vehicles in various forms. The simulation results show that control forces obtained from the approach can regulate motions of unmanned ground vehicles to maneuver in desired formations.

Grounded theory research: literature reviewing and reflexivity.

Science.gov (United States)

McGhee, Gerry; Marland, Glenn R; Atkinson, Jacqueline

2007-11-01

This paper is a report of a discussion of the arguments surrounding the role of the initial literature review in grounded theory. Researchers new to grounded theory may find themselves confused about the literature review, something we ourselves experienced, pointing to the need for clarity about use of the literature in grounded theory to help guide others about to embark on similar research journeys. The arguments for and against the use of a substantial topic-related initial literature review in a grounded theory study are discussed, giving examples from our own studies. The use of theoretically sampled literature and the necessity for reflexivity are also discussed. Reflexivity is viewed as the explicit quest to limit researcher effects on the data by awareness of self, something seen as integral both to the process of data collection and the constant comparison method essential to grounded theory. A researcher who is close to the field may already be theoretically sensitized and familiar with the literature on the study topic. Use of literature or any other preknowledge should not prevent a grounded theory arising from the inductive-deductive interplay which is at the heart of this method. Reflexivity is needed to prevent prior knowledge distorting the researcher's perceptions of the data.

Cooperative heat transfer and ground coupled storage system

Science.gov (United States)

Metz, P.D.

A cooperative heat transfer and ground coupled storage system wherein collected solar heat energy is ground stored and permitted to radiate into the adjacent ground for storage therein over an extended period of time when such heat energy is seasonally maximally available. Thereafter, when said heat energy is seasonally minimally available and has propagated through the adjacent ground a substantial distance, the stored heat energy may be retrieved by a circumferentially arranged heat transfer means having a high rate of heat transfer.

Compensation for incoherent ground motion

International Nuclear Information System (INIS)

Shigeru, Takeda; Hiroshi, Matsumoto; Masakazu, Yoshioka; Yasunori, Takeuchi; Kikuo, Kudo; Tsuneya, Tsubokawa; Mitsuaki, Nozaki; Kiyotomo, Kawagoe

1999-01-01

The power spectrum density and coherence function for ground motions are studied for the construction of the next generation electron-positron linear collider. It should provide a center of mass energy between 500 GeV-1 TeV with luminosity as high as 10 33 to 10 34 cm -2 sec -1 . Since the linear collider has a relatively slow repetition rate, large number of particles and small sizes of the beam should be generated and preserved in the machine to obtain the required high luminosity. One of the most critical parameters is the extremely small vertical beam size at the interaction point, thus a proper alignment system for the focusing and accelerating elements of the machine is necessary to achieve the luminosity. We describe recent observed incoherent ground motions and an alignment system to compensate the distortion by the ground motions. (authors)

Ambulatory Measurement of Ground Reaction Forces

NARCIS (Netherlands)

Veltink, Peter H.; Liedtke, Christian; Droog, Ed

2004-01-01

The measurement of ground reaction forces is important in the biomechanical analysis of gait and other motor activities. It is the purpose of this study to show the feasibility of ambulatory measurement of ground reaction forces using two six degrees of freedom sensors mounted under the shoe. One

Ground Truth Collections at the MTI Core Sites

International Nuclear Information System (INIS)

Garrett, A.J.

2001-01-01

The Savannah River Technology Center (SRTC) selected 13 sites across the continental US and one site in the western Pacific to serve as the primary or core site for collection of ground truth data for validation of MTI science algorithms. Imagery and ground truth data from several of these sites are presented in this paper. These sites are the Comanche Peak, Pilgrim and Turkey Point power plants, Ivanpah playas, Crater Lake, Stennis Space Center and the Tropical Western Pacific ARM site on the island of Nauru. Ground truth data includes water temperatures (bulk and skin), radiometric data, meteorological data and plant operating data. The organizations that manage these sites assist SRTC with its ground truth data collections and also give the MTI project a variety of ground truth measurements that they make for their own purposes. Collectively, the ground truth data from the 14 core sites constitute a comprehensive database for science algorithm validation

Dynamic tire pressure sensor for measuring ground vibration.

Science.gov (United States)

Wang, Qi; McDaniel, James Gregory; Wang, Ming L

2012-11-07

This work presents a convenient and non-contact acoustic sensing approach for measuring ground vibration. This approach, which uses an instantaneous dynamic tire pressure sensor (DTPS), possesses the capability to replace the accelerometer or directional microphone currently being used for inspecting pavement conditions. By measuring dynamic pressure changes inside the tire, ground vibration can be amplified and isolated from environmental noise. In this work, verifications of the DTPS concept of sensing inside the tire have been carried out. In addition, comparisons between a DTPS, ground-mounted accelerometer, and directional microphone are made. A data analysis algorithm has been developed and optimized to reconstruct ground acceleration from DTPS data. Numerical and experimental studies of this DTPS reveal a strong potential for measuring ground vibration caused by a moving vehicle. A calibration of transfer function between dynamic tire pressure change and ground acceleration may be needed for different tire system or for more accurate application.

Grounding line processes on the Totten Glacier

Science.gov (United States)

Cook, S.; Watson, C. S.; Galton-Fenzi, B.; Peters, L. E.; Coleman, R.

2017-12-01

The Totten Glacier has been an area of recent interest due to its large drainage basin, much of which is grounded below sea level and has a history of large scale grounding line movement. Reports that warm water reaches the sub-ice shelf cavity have led to speculation that it could be vulnerable to future grounding line retreat. Over the Antarctic summer 2016/17 an array of 6 GPS and autonomous phase-sensitive radar (ApRES) units were deployed in the grounding zone of the Totten Glacier. These instruments measure changes in ice velocity and thickness which can be used to investigate both ice dynamics across the grounding line, and the interaction between ice and ocean in the subglacial cavity. Basal melt rates calculated from the ApRES units on floating ice range from 1 to 17 m/a. These values are significantly lower than previous estimates of basal melt rate produced by ocean modelling of the subglacial cavity. Meanwhile, GPS-derived velocity and elevation on the surface of the ice show a strong tidal signal, as does the vertical strain rate within the ice derived from internal layering from the ApRES instruments. These results demonstrate the significance of the complex grounding pattern of the Totten Glacier. The presence of re-grounding points has significant implications for the dynamics of the glacier and the ocean circulation within the subglacial cavity. We discuss what can be learned from our in situ measurements, and how they can be used to improve models of the glacier's future behaviour.

Heat recovery from ground below the solar pond

NARCIS (Netherlands)

Ganguly, S.; Date, Abhijit; Akbarzadeh, Aliakbar

2017-01-01

The method of heat recovery from the ground below solar ponds is investigated in the present brief note. Solar ponds lose considerable amount of heat from its bottom to the ground due to temperature gradient between them. This waste heat from ground, which is at different temperature at different

Modelling of the evolution of ground waters in a granite system at low temperature: the Stripa ground waters, Sweden

International Nuclear Information System (INIS)

Grimaud, D.; Michard, G.; Beaucaire, C.

1990-01-01

From chemical data on the Stripa ground waters we have tried to model the evolution of the chemical composition of a ground water in a granitic system at low temperature. The existence of two end-member ground water compositions made it possible first, to test the conventional model of a geothermal system according to which an overall equilibrium between the waters and a given mineral assemblage can be defined, and then to show that such a model could be extended to low temperatures (10 o C). Conversely, if we know the mineral assemblage, the equilibration temperature and the charge of the mobile ions (in this case, Cl), the composition of the solution is entirely fixed. In our model of the Stripa ground waters, the existence of two end-member ground water compositions can be explained by an evolution from a ''kaolinite-albite-laumontite'' equilibrium to a ''prehnite-albite-laumontite'' equilibrium, the latter requiring less Al than the former. We have also emphasized the importance of the Cl ion concentrations of the ground waters, because they can be considered as indicators of the degree of reaction progress between rock and water, thus determining the degree of equilibration of the system. (author)

Biodiesel Production from Spent Coffee Grounds

Science.gov (United States)

Blinová, Lenka; Bartošová, Alica; Sirotiak, Maroš

2017-06-01

The residue after brewing the spent coffee grounds is an oil-containing waste material having a potential of being used as biodiesel feedstock. Biodiesel production from the waste coffee grounds oil involves collection and transportation of coffee residue, drying, oil extraction, and finally production of biodiesel. Different methods of oil extraction with organic solvents under different conditions show significant differences in the extraction yields. In the manufacturing of biodiesel from coffee oil, the level of reaction completion strongly depends on the quality of the feedstock oil. This paper presents an overview of oil extraction and a method of biodiesel production from spent coffee grounds.

Great Moravian burial grounds in Rajhrad and Rajhradice

OpenAIRE

Hendrychová, Soňa

2015-01-01

The diploma thesis presented deals with an overall assessment of the Great Moravian burial ground in Rajhrad (Brno- venkov), which was excavated in the years 1972 to 1976. The work is based on a catalogue of this burial ground and the neighbouring one in Rajhradice published by Čeněk Staňa. It follows individual aspects of funeral rites at a necropolis and evaluates the inventory of the graves. Based on the findings, the work dates the burial ground, compares with burial ground in Rajhradice ...

On the ground state of Yang-Mills theory

International Nuclear Information System (INIS)

Bakry, Ahmed S.; Leinweber, Derek B.; Williams, Anthony G.

2011-01-01

Highlights: → The ground state overlap for sets of meson potential trial states is measured. → Non-uniform gluonic distributions are probed via Wilson loop operator. → The locally UV-regulated flux-tube operators can optimize the ground state overlap. - Abstract: We investigate the overlap of the ground state meson potential with sets of mesonic-trial wave functions corresponding to different gluonic distributions. We probe the transverse structure of the flux tube through the creation of non-uniform smearing profiles for the string of glue connecting two color sources in Wilson loop operator. The non-uniformly UV-regulated flux-tube operators are found to optimize the overlap with the ground state and display interesting features in the ground state overlap.

A Guide for Using the Transient Ground-Water Flow Model of the Death Valley Regional Ground-Water Flow System, Nevada and California

Energy Technology Data Exchange (ETDEWEB)

Joan B. Blainey; Claudia C. Faunt, and Mary C. Hill

2006-05-16

This report is a guide for executing numerical simulations with the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California using the U.S. Geological Survey modular finite-difference ground-water flow model, MODFLOW-2000. Model inputs, including observations of hydraulic head, discharge, and boundary flows, are summarized. Modification of the DVRFS transient ground-water model is discussed for two common uses of the Death Valley regional ground-water flow system model: predictive pumping scenarios that extend beyond the end of the model simulation period (1998), and model simulations with only steady-state conditions.

Puzzling the Picture Using Grounded Theory

Science.gov (United States)

Bennett, Elisabeth E.

2016-01-01

Since the first publication by Glaser and Strauss in 1967, Grounded Theory has become a highly influential research approach in the social sciences. The approach provides techniques and coding strategies for building theory inductively from the "ground up" as concepts within the data earn relevance into an evolving substantive theory.…

Ground-based observations of exoplanet atmospheres

NARCIS (Netherlands)

Mooij, Ernst Johan Walter de

2011-01-01

This thesis focuses on the properties of exoplanet atmospheres. The results for ground-based near-infrared secondary eclipse observations of three different exoplanets, TrES-3b, HAT-P-1b and WASP-33b, are presented which have been obtained with ground-based telescopes as part of the GROUSE project.

14 CFR 415.117 - Ground safety.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Ground safety. 415.117 Section 415.117... TRANSPORTATION LICENSING LAUNCH LICENSE Safety Review and Approval for Launch of an Expendable Launch Vehicle From a Non-Federal Launch Site § 415.117 Ground safety. (a) General. An applicant's safety review...

Ground Truth Annotation in T Analyst

DEFF Research Database (Denmark)

2015-01-01

This video shows how to annotate the ground truth tracks in the thermal videos. The ground truth tracks are produced to be able to compare them to tracks obtained from a Computer Vision tracking approach. The program used for annotation is T-Analyst, which is developed by Aliaksei Laureshyn, Ph...

Examining the Nexus between Grounded Theory and Symbolic Interactionism

Directory of Open Access Journals (Sweden)

P. Jane Milliken RN, PhD

2012-12-01

Full Text Available Grounded theory is inherently symbolic interactionist; however, not all grounded theory researchers appreciate its importance or benefit from its influence. Elsewhere, we have written about the intrinsic relationship between grounded theory and symbolic interactionism, highlighting the silent, fundamental contribution of symbolic interactionism to the methodology. At the same time, there are significant insights to be had by bringing a conscious awareness of the philosophy of symbolic interactionism to grounded theory research. In this article we discuss the symbolic interactionist concepts of mind, self, and society, and their applicability in grounded theorizing. Our purpose is to highlight foundational concepts of symbolic interactionism and their centrality in the processes of conducting grounded theory research.

Ground use by northern muriquis (Brachyteles hypoxanthus).

Science.gov (United States)

Mourthé, Italo M C; Guedes, Danusa; Fidelis, Janaína; Boubli, Jean P; Mendes, Sérgio L; Strier, Karen B

2007-06-01

Many arboreal primates descend to the ground, a custom that may occur more frequently in disturbed habitats, and in the presence of researchers to whom the primates are habituated. In this paper, we describe opportunistic observations of ground use in two groups of northern muriquis (Brachyteles hypoxanthus) at the RPPN Feliciano Miguel Abdala, Minas Gerais, Brazil. Members of both groups were observed drinking, resting, feeding, playing, and traveling on the ground to different degrees, and variation in the levels of habituation of the two groups may be responsible for the differences in the distribution of their terrestrial activities. The potential increase in vulnerability to predation or disease owing to ground use has implications for the conservation of this critically endangered species. (c) 2007 Wiley-Liss, Inc.

Hanford Site ground-water monitoring for 1990

International Nuclear Information System (INIS)

Evans, J.C.; Bryce, R.W.; Bates, D.J.

1992-06-01

The Pacific Northwest Laboratory monitors ground-water quality across the Hanford Site for the US Department of Energy (DOE) to assess the impact of Site operations on the environment. Monitoring activities were conducted to determine the distribution of mobile radionuclides and identify chemicals present in ground water as a result of Site operations and whenever possible, relate the distribution of these constituents to Site operations. To comply with the Resource Conservation and Recovery Act, additional monitoring was conducted at individual waste sites by the Site Operating Contractor, Westinghouse Hanford Company (WHC), to assess the impact that specific facilities have had on ground-water quality. Six hundred and twenty-nine wells were sampled during 1990 by all Hanford ground-water monitoring activities

TNX Burying Ground: Environmental information document

International Nuclear Information System (INIS)

Dunaway, J.K.W.; Johnson, W.F.; Kingley, L.E.; Simmons, R.V.; Bledsoe, H.W.

1987-03-01

The TNX Burying Ground, located within the TNX Area of the Savannah River Plant (SRP), was originally built to dispose of debris from an experimental evaporator explosion at TNX in 1953. This evaporator contained approximately 590 kg of uranyl nitrate. From 1980 to 1984, much of the waste material buried at TNX was excavated and sent to the SRP Radioactive Waste Burial Grounds for reburial. An estimated 27 kg of uranyl nitrate remains buried at TNX. The TNX Burying Ground consists of three sites known to contain waste and one site suspected of containing waste material. All four sites are located within the TNX security fenceline. Groundwater at the TNX Burying Ground was not evaluated because there are no groundwater monitoring wells installed in the immediate vicinity of this waste site. The closure options considered for the TNX Burying Ground are waste removal and closure, no waste removal and closure, and no action. The predominant pathways for human exposure to chemical and/or radioactive constituents are through surface, subsurface, and atmospheric transport. Modeling calculations were made to determine the risks to human population via these general pathways for the three postulated closure options. An ecological assessment was conducted to predict the environmental impacts on aquatic and terrestrial biota. The relative costs for each of the closure options were estimated

Ground-Water Hydrology and Projected Effects of Ground-Water Withdrawals in the Sevier Desert, Utah

OpenAIRE

United States Geological Survey

1983-01-01

The principal ground-water reservoir in the Sevier Desert is the unconsolidated basin fill. The fill has been divided generally into aquifers and confining beds, although there are no clearcut boundaries between these units--the primary aquifers are the shallow and deep artesian aquifers. Recharge to the ground-water reservoir is by infiltration of precipitation; seepage from streams, canals, reservoirs, and unconsumed irrigation water; and subsurface inflow from consolidated rocks in mount...

Demystifying Theoretical Sampling in Grounded Theory Research

Directory of Open Access Journals (Sweden)

Jenna Breckenridge BSc(Hons,Ph.D.Candidate

2009-06-01

Full Text Available Theoretical sampling is a central tenet of classic grounded theory and is essential to the development and refinement of a theory that is ‘grounded’ in data. While many authors appear to share concurrent definitions of theoretical sampling, the ways in which the process is actually executed remain largely elusive and inconsistent. As such, employing and describing the theoretical sampling process can present a particular challenge to novice researchers embarking upon their first grounded theory study. This article has been written in response to the challenges faced by the first author whilst writing a grounded theory proposal. It is intended to clarify theoretical sampling for new grounded theory researchers, offering some insight into the practicalities of selecting and employing a theoretical sampling strategy. It demonstrates that the credibility of a theory cannot be dissociated from the process by which it has been generated and seeks to encourage and challenge researchers to approach theoretical sampling in a way that is apposite to the core principles of the classic grounded theory methodology.

Ground-truth measurement systems

Science.gov (United States)

Serafin, R.; Seliga, T. A.; Lhermitte, R. M.; Nystuen, J. A.; Cherry, S.; Bringi, V. N.; Blackmer, R.; Heymsfield, G. M.

1981-01-01

Ground-truth measurements of precipitation and related weather events are an essential component of any satellite system designed for monitoring rainfall from space. Such measurements are required for testing, evaluation, and operations; they provide detailed information on the actual weather events, which can then be compared with satellite observations intended to provide both quantitative and qualitative information about them. Also, very comprehensive ground-truth observations should lead to a better understanding of precipitation fields and their relationships to satellite data. This process serves two very important functions: (a) aiding in the development and interpretation of schemes of analyzing satellite data, and (b) providing a continuing method for verifying satellite measurements.

From Computational Photobiology to the Design of Vibrationally Coherent Molecular Devices and Motors

Science.gov (United States)

Olivucci, Massimo

2014-03-01

In the past multi-configurational quantum chemical computations coupled with molecular mechanics force fields have been employed to investigate spectroscopic, thermal and photochemical properties of visual pigments. Here we show how the same computational technology can nowadays be used to design, characterize and ultimately, prepare light-driven molecular switches which mimics the photophysics of the visual pigment bovine rhodopsin (Rh). When embedded in the protein cavity the chromophore of Rh undergoes an ultrafast and coherent photoisomerization. In order to design a synthetic chromophore displaying similar properties in common solvents, we recently focused on indanylidene-pyrroline (NAIP) systems. We found that these systems display light-induced ground state coherent vibrational motion similar to the one detected in Rh. Semi-classical trajectories provide a mechanistic description of the structural changes associated to the observed coherent motion which is shown to be ultimately due to periodic changes in the π-conjugation.

Vibrational treatment of the formic acid double minimum case in valence coordinates

Science.gov (United States)

Richter, Falk; Carbonnière, P.

2018-02-01

One single full dimensional valence coordinate HCOOH ground state potential energy surface accurate for both cis and trans conformers for all levels up to 6000 cm-1 relative to trans zero point energy has been generated at CCSD(T)-F12a/aug-cc-pVTZ level. The fundamentals and a set of eigenfunctions complete up to about 3120 and 2660 cm-1 for trans- and cis-HCOOH, respectively, have been calculated and assigned using the improved relaxation method of the Heidelberg multi-configuration time-dependent Hartree package and an exact expression for the kinetic energy in valence coordinates generated by the TANA program. The calculated trans fundamental transition frequencies agree with experiment to within 5 cm-1. A few reassignments are suggested. Our results discard any cis trans delocalization effects for vibrational eigenfunctions up to 3640 cm-1 relative to trans zero point energy.

X-ray transitions in highly charged neonlike ions

International Nuclear Information System (INIS)

Beiersdorfer, P.; von Gjoeler, S.; Bitter, M.

1987-11-01

Wavelength measurements of n=3 to n=2 transitions in neonlike Xe 44+ , La 47+ , Nd 50+ , and Eu 53+ have been made using a high-resolution Bragg-crystal spectrometer on the Princeton Large Torus tokamak. The measurements cover the wavelength regions 2.00 to 3.00 (angstrom) and include the electric dipole, and the electric and magnetic quadrupole transitions. The measured wavelengths are compared to energy levels obtained from a multiconfigurational Dirac-Fock calculation. Systematic differences between the experimental and theoretical values are found, which vary smoothly with atomic number. The magnitude of the differences depends on the particular type of transition and ranges from -2.8 eV to +2.2 eV. Inclusion of electron correlation corrections due to ground state correlations and (super) Coster-Kronig type fluctuations in the theoretical energies is shown to reduce the differences for some but not all types of transitions

Free Swimming in Ground Effect

Science.gov (United States)

Cochran-Carney, Jackson; Wagenhoffer, Nathan; Zeyghami, Samane; Moored, Keith

2017-11-01

A free-swimming potential flow analysis of unsteady ground effect is conducted for two-dimensional airfoils via a method of images. The foils undergo a pure pitching motion about their leading edge, and the positions of the body in the streamwise and cross-stream directions are determined by the equations of motion of the body. It is shown that the unconstrained swimmer is attracted to a time-averaged position that is mediated by the flow interaction with the ground. The robustness of this fluid-mediated equilibrium position is probed by varying the non-dimensional mass, initial conditions and kinematic parameters of motion. Comparisons to the foil's fixed-motion counterpart are also made to pinpoint the effect that free swimming near the ground has on wake structures and the fluid-mediated forces over time. Optimal swimming regimes for near-boundary swimming are determined by examining asymmetric motions.

Launch and Landing Effects Ground Operations (LLEGO) Model

Science.gov (United States)

2008-01-01

LLEGO is a model for understanding recurring launch and landing operations costs at Kennedy Space Center for human space flight. Launch and landing operations are often referred to as ground processing, or ground operations. Currently, this function is specific to the ground operations for the Space Shuttle Space Transportation System within the Space Shuttle Program. The Constellation system to follow the Space Shuttle consists of the crewed Orion spacecraft atop an Ares I launch vehicle and the uncrewed Ares V cargo launch vehicle. The Constellation flight and ground systems build upon many elements of the existing Shuttle flight and ground hardware, as well as upon existing organizations and processes. In turn, the LLEGO model builds upon past ground operations research, modeling, data, and experience in estimating for future programs. Rather than to simply provide estimates, the LLEGO model s main purpose is to improve expenses by relating complex relationships among functions (ground operations contractor, subcontractors, civil service technical, center management, operations, etc.) to tangible drivers. Drivers include flight system complexity and reliability, as well as operations and supply chain management processes and technology. Together these factors define the operability and potential improvements for any future system, from the most direct to the least direct expenses.

Wind uplift of radioactive dust from the ground

International Nuclear Information System (INIS)

Makhon'ko, K.P.

1992-01-01

Near nuclear power plants the recontamination of the atmosphere near the ground becomes dangerous, if a radioactive zone has formed at the site. Wind can easily carry toxic dust from the polluted territory of neighboring industrial enterprises. Moreover, wind erosion of the soil during the summer or transport of radioactive snow by a snowstorm during the winter can displace the boundaries of the contaminated radioactive zone. In Russia the investigation of wind pickup of radioactive dust from the ground began after a radiation accident occurred at a storage facility in the Southern Urals in 1957, as a result of which a contaminated zone formed in the area. Since the direct mechanism of detachment of dust particles from the ground is not important in studying the results of the raising of radioactive dust into the atmosphere by wind, the authors do not distinguish between wind pickup and wind erosion, and the entire process wind pickup of radioactivity from the ground. After the radiation accident at the Chernobyl nuclear power plant a new generation of investigators began to study wind pickup of radioactive dust from the ground, and the process under consideration was sometimes referred to as wind uplift. The intensity of the process of wind pickup of radioactive dust from the ground is characterized by the wind pickup coefficient α, which is the coefficient of proportionality between the upward flux Q of radioactivity from the ground and the density A of radioactive contamination of the ground: α = Q/A. Physically, the coefficient α is the upward flux of the impurity from the ground with unit contamination density, i.e., the intensity of dust contamination or the fraction of radioactivity picked up by the wind from the ground per unit time. The greatest difficulty in determining α experimentally under dusty conditions is measuring correctly the upward radioactivity flux Q. The author discusses three methods for determining this quantity

Attention and competition in figure-ground perception.

Science.gov (United States)

Peterson, Mary A; Salvagio, Elizabeth

2009-01-01

What are the roles of attention and competition in determining where objects lie in the visual field, a phenomenon known as figure-ground perception? In this chapter, we review evidence that attention and other high-level factors such as familiarity affect figure-ground perception, and we discuss models that implement these effects. Next, we consider the Biased Competition Model of Attention in which attention is used to resolve the competition for neural representation between two nearby stimuli; in this model the response to the stimulus that loses the competition is suppressed. In the remainder of the chapter we discuss recent behavioral evidence that figure-ground perception entails between-object competition in which the response to the shape of the losing competitor is suppressed. We also describe two experiments testing whether more attention is drawn to resolve greater figure-ground competition, as would be expected if the Biased Competition Model of Attention extends to figure-ground perception. In these experiments we find that responses to targets on the location of a losing strong competitor are slowed, consistent with the idea that the location of the losing competitor is suppressed, but responses to targets on the winning competitor are not speeded, which is inconsistent with the hypothesis that attention is used to resolve figure-ground competition. In closing, we discuss evidence that attention can operate by suppression as well as by facilitation.

Guidelines for determining design basis ground motions

International Nuclear Information System (INIS)

1993-11-01

This report develops and applies a method for estimating strong earthquake ground motion. The emphasis of this study is on ground motion estimation in Eastern North America (east of the Rocky Mountains), with particular emphasis on the Eastern United States and southeastern Canada. Specifically considered are ground motions resulting from earthquakes with magnitudes from 5 to 8, fault distances from 0 to 500 km, and frequencies from 1 to 35 Hz. The two main objectives were: (1) to develop generic relations for estimating ground motion appropriate for site screening; and (2) to develop a guideline for conducting a thorough site investigation needed to define the seismic design basis. For the first objective, an engineering model was developed to predict the expected ground motion on rock sites, with an additional set of amplification factors to account for the response of the soil column over rock at soil sites. The results incorporate best estimates of ground motion as well as the randomness and uncertainty associated with those estimates. For the second objective, guidelines were developed for gathering geotechnical information at a site and using this information in calculating site response. As a part of this development, an extensive set of geotechnical and seismic investigations was conducted at three reference sites. Together, the engineering model and guidelines provide the means to select and assess the seismic suitability of a site

PV Systems Reliability Final Technical Report: Ground Fault Detection

Energy Technology Data Exchange (ETDEWEB)

Lavrova, Olga [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Flicker, Jack David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Johnson, Jay [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-01-01

We have examined ground faults in PhotoVoltaic (PV) arrays and the efficacy of fuse, current detection (RCD), current sense monitoring/relays (CSM), isolation/insulation (Riso) monitoring, and Ground Fault Detection and Isolation (GFID) using simulations based on a Simulation Program with Integrated Circuit Emphasis SPICE ground fault circuit model, experimental ground faults installed on real arrays, and theoretical equations.

Analytical and finite element modeling of grounding systems

Energy Technology Data Exchange (ETDEWEB)

Luz, Mauricio Valencia Ferreira da [University of Santa Catarina (UFSC), Florianopolis, SC (Brazil)], E-mail: mauricio@grucad.ufsc.br; Dular, Patrick [University of Liege (Belgium). Institut Montefiore], E-mail: Patrick.Dular@ulg.ac.be

2007-07-01

Grounding is the art of making an electrical connection to the earth. This paper deals with the analytical and finite element modeling of grounding systems. An electrokinetic formulation using a scalar potential can benefit from floating potentials to define global quantities such as electric voltages and currents. The application concerns a single vertical grounding with one, two and three-layer soil, where the superior extremity stays in the surface of the soil. This problem has been modeled using a 2D axi-symmetric electrokinetic formulation. The grounding resistance obtained by finite element method is compared with the analytical one for one-layer soil. With the results of this paper it is possible to show that finite element method is a powerful tool in the analysis of the grounding systems in low frequencies. (author)

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

Energy Technology Data Exchange (ETDEWEB)

Levinson, Ronnen 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.

Intelligent systems for KSC ground processing

Science.gov (United States)

Heard, Astrid E.

1992-01-01

The ground processing and launch of Shuttle vehicles and their payloads is the primary task of Kennedy Space Center. It is a process which is largely manual and contains little inherent automation. Business is conducted today much as it was during previous NASA programs such as Apollo. In light of new programs and decreasing budgets, NASA must find more cost effective ways in which to do business while retaining the quality and safety of activities. Advanced technologies including artificial intelligence could cut manpower and processing time. This paper is an overview of the research and development in Al technology at KSC with descriptions of the systems which have been implemented, as well as a few under development which are promising additions to ground processing software. Projects discussed cover many facets of ground processing activities, including computer sustaining engineering, subsystem monitor and diagnosis tools and launch team assistants. The deployed Al applications have proven an effectiveness which has helped to demonstrate the benefits of utilizing intelligent software in the ground processing task.

Purely temporal figure-ground segregation.

Science.gov (United States)

Kandil, F I; Fahle, M

2001-05-01

Visual figure-ground segregation is achieved by exploiting differences in features such as luminance, colour, motion or presentation time between a figure and its surround. Here we determine the shortest delay times required for figure-ground segregation based on purely temporal features. Previous studies usually employed stimulus onset asynchronies between figure- and ground-containing possible artefacts based on apparent motion cues or on luminance differences. Our stimuli systematically avoid these artefacts by constantly showing 20 x 20 'colons' that flip by 90 degrees around their midpoints at constant time intervals. Colons constituting the background flip in-phase whereas those constituting the target flip with a phase delay. We tested the impact of frequency modulation and phase reduction on target detection. Younger subjects performed well above chance even at temporal delays as short as 13 ms, whilst older subjects required up to three times longer delays in some conditions. Figure-ground segregation can rely on purely temporal delays down to around 10 ms even in the absence of luminance and motion artefacts, indicating a temporal precision of cortical information processing almost an order of magnitude lower than the one required for some models of feature binding in the visual cortex [e.g. Singer, W. (1999), Curr. Opin. Neurobiol., 9, 189-194]. Hence, in our experiment, observers are unable to use temporal stimulus features with the precision required for these models.

Guide to North Dakota's ground-water resources

Science.gov (United States)

Paulson, Q.F.

1983-01-01

Ground water, the water we pump from the Earth through wells or that which flows naturally from springs, is one of North Dakota's most valuable resources. More than 60 percent of the people living in the State use ground water for one purpose of another. It is the only source of water for thousands of farm families and their livestock. Almost all smaller cities and villages depend solely on groudn water as a source of supply. Increasingly, ground water is being used to irrigate crops and grasslands (fig. 1) during protracted dry spells so common in North Dakota. During recent years there has been a rapid development of rural water ditribution systems in which thousands of farms and rurals residences are connected via underground pipeline to a single water source, usually wells pumping ground water.

Solid waste burial grounds interim safety analysis

International Nuclear Information System (INIS)

Saito, G.H.

1994-01-01

This Interim Safety Analysis document supports the authorization basis for the interim operation and restrictions on interim operations for the near-surface land disposal of solid waste in the Solid Waste Burial Grounds. The Solid Waste Burial Grounds Interim Safety Basis supports the upgrade progress for the safety analysis report and the technical safety requirements for the operations in the Solid Waste Burial Grounds. Accident safety analysis scenarios have been analyzed based on the significant events identified in the preliminary hazards analysis. The interim safety analysis provides an evaluation of the operations in the Solid Waste Burial Grounds to determine if the radiological and hazardous material exposures will be acceptable from an overall health and safety standpoint to the worker, the onsite personnel, the public, and the environment

Solid waste burial grounds interim safety analysis

Energy Technology Data Exchange (ETDEWEB)

Saito, G.H.

1994-10-01

This Interim Safety Analysis document supports the authorization basis for the interim operation and restrictions on interim operations for the near-surface land disposal of solid waste in the Solid Waste Burial Grounds. The Solid Waste Burial Grounds Interim Safety Basis supports the upgrade progress for the safety analysis report and the technical safety requirements for the operations in the Solid Waste Burial Grounds. Accident safety analysis scenarios have been analyzed based on the significant events identified in the preliminary hazards analysis. The interim safety analysis provides an evaluation of the operations in the Solid Waste Burial Grounds to determine if the radiological and hazardous material exposures will be acceptable from an overall health and safety standpoint to the worker, the onsite personnel, the public, and the environment.

Ground Control for Emplacement Drifts for LA

International Nuclear Information System (INIS)

Y. Sun

2004-01-01

The purpose of this calculation is to analyze the stability of repository emplacement drifts during the preclosure period, and to provide a final ground support method for emplacement drifts for the License Application (LA). The scope of the work includes determination of input parameter values and loads, selection of appropriate process and methods for the calculation, application of selected methods, such as empirical or analytical, to the calculation, development and execution of numerical models, and evaluation of results. Results from this calculation are limited to use for design of the emplacement drifts and the final ground support system installed in these drifts. The design of non-emplacement openings and their ground support systems is covered in the ''Ground Control for Non-Emplacement Drifts for LA'' (BSC 2004c)

Collison and Grounding

DEFF Research Database (Denmark)

Wang, G.; Ji, C.; Kuhala, P.

2006-01-01

COMMITTEE MANDATE Concern for structural arrangements on ships and floating structures with regard to their integrity and adequacy in the events of collision and grounding, with the view towards risk assessment and management. Consideration shall be given to the frequency of occurrence...

The ground-beetles (Coleoptera, Carabidae) of Nukatlinskiy watershed

OpenAIRE

G. M. Nahibasheva; Sh. M. Imanaliev

2008-01-01

The article is devoted to studying of ground-beetles fauna of Nukatlinskiy watershed of Republic Dagestan. For the first time the specific structure of ground-beetles this area, the numbering 109 kinds concerning 31 sort is resulted. The analysis of sexual structure of populations and seasonal dynamics of activity ground-beetles is lead.

Ground-water monitoring and modeling at the Hanford Site

International Nuclear Information System (INIS)

Mitchell, P.J.; Freshley, M.D.

1987-01-01

The ground-water monitoring program at the Hanford Site in southeastern Washington State is continually evolving in response to changing operations at the site, changes in the ground-water flow system, movement of the constituents in the aquifers, and regulatory requirements. Sampling and analysis of ground water, along with ground-water flow and solute transport modeling are used to evaluate the movement and resulting distributions of radionuclides and hazardous chemical constituents in the unconfined aquifer. Evaluation of monitoring results, modeling, and information on waste management practices are being combined to continually improve the network of ground-water monitoring wells at the site

Ground-water monitoring and modeling at the Hanford Site

International Nuclear Information System (INIS)

Mitchell, P.J.; Freshley, M.D.

1987-01-01

The ground-water monitoring program at the Hanford Site in southeastern Washington State is continually evolving in response to changing operations at the site, changes in the ground-water flow system, movement of the constituents in the aquifers, and regulatory requirements. Sampling and analysis of ground water, along with ground-water flow and solute transport modeling are used ito evaluate the movement and resulting distributions of radionuclides and hazardous chemical constituents in the unconfined aquifer. Evaluation of monitoring results, modeling, and information on waste management practices are being combined to continually improve the network of ground-water monitoring wells at the site

Ground motion modeling of Hayward fault scenario earthquakes II:Simulation of long-period and broadband ground motions

Energy Technology Data Exchange (ETDEWEB)

Aagaard, B T; Graves, R W; Rodgers, A; Brocher, T M; Simpson, R W; Dreger, D; Petersson, N A; Larsen, S C; Ma, S; Jachens, R C

2009-11-04

We simulate long-period (T > 1.0-2.0 s) and broadband (T > 0.1 s) ground motions for 39 scenarios earthquakes (Mw 6.7-7.2) involving the Hayward, Calaveras, and Rodgers Creek faults. For rupture on the Hayward fault we consider the effects of creep on coseismic slip using two different approaches, both of which reduce the ground motions compared with neglecting the influence of creep. Nevertheless, the scenario earthquakes generate strong shaking throughout the San Francisco Bay area with about 50% of the urban area experiencing MMI VII or greater for the magnitude 7.0 scenario events. Long-period simulations of the 2007 Mw 4.18 Oakland and 2007 Mw 4.5 Alum Rock earthquakes show that the USGS Bay Area Velocity Model version 08.3.0 permits simulation of the amplitude and duration of shaking throughout the San Francisco Bay area, with the greatest accuracy in the Santa Clara Valley (San Jose area). The ground motions exhibit a strong sensitivity to the rupture length (or magnitude), hypocenter (or rupture directivity), and slip distribution. The ground motions display a much weaker sensitivity to the rise time and rupture speed. Peak velocities, peak accelerations, and spectral accelerations from the synthetic broadband ground motions are, on average, slightly higher than the Next Generation Attenuation (NGA) ground-motion prediction equations. We attribute at least some of this difference to the relatively narrow width of the Hayward fault ruptures. The simulations suggest that the Spudich and Chiou (2008) directivity corrections to the NGA relations could be improved by including a dependence on the rupture speed and increasing the areal extent of rupture directivity with period. The simulations also indicate that the NGA relations may under-predict amplification in shallow sedimentary basins.

Effect of electrode shape on grounding resistances - Part 2

DEFF Research Database (Denmark)

Tomaskovicova, Sonia; Ingeman-Nielsen, Thomas; Christiansen, Anders V.

2016-01-01

Although electric resistivity tomography (ERT) is now regarded as a standard tool in permafrost monitoring, high grounding resistances continue to limit the acquisition of time series over complete freeze-thaw cycles. In an attempt to alleviate the grounding resistance problem, we have tested three...... electrode designs featuring increasing sizes and surface area, in the laboratory and at three different field sites in Greenland. Grounding resistance measurements showed that changing the electrode shape (using plates instead of rods) reduced the grounding resistances at all sites by 28%-69% during...... unfrozen and frozen ground conditions. Using meshes instead of plates (the same rectangular shape and a larger effective surface area) further improved the grounding resistances by 29%-37% in winter. Replacement of rod electrodes of one entire permanent permafrost monitoring array by meshes resulted...

COMPARATIVE ANALYSIS OF GROUNDING RESISTANCE VALUE IN SOIL AND SEPTICTANK

Directory of Open Access Journals (Sweden)

Abdul Syakur

2012-02-01

Full Text Available The aim of grounding system to protect of electrical equipment and instrumentation system and peopletogether. The lightning stroke near the strucutre of building can damage of equipment and instrumentationsystem. Therefore, it is very important to protect theese electrical and electronic equipment from lightningstrike uses lightning protection system and grounding system.This paper presents kind of grounding system at type of soil and place. The measurement of groundingresistance in soil and septictank have done. Types of soil for grounding resistance measuring aremarshland, clay and rockland.The measurement results of grounding resistance show that value of grounding resistance depend ondeepness of electrode and kind of soil and septictank. Grounding resistance value in septictank is morelower than soil.

Sail GTS ground system analysis: Avionics system engineering

Science.gov (United States)

Lawton, R. M.

1977-01-01

A comparison of two different concepts for the guidance, navigation and control test set signal ground system is presented. The first is a concept utilizing a ground plate to which crew station, avionics racks, electrical power distribution system, master electrical common connection assembly and marshall mated elements system grounds are connected by 4/0 welding cable. An alternate approach has an aluminum sheet interconnecting the signal ground reference points between the crew station and avionics racks. The comparison analysis quantifies the differences between the two concepts in terms of dc resistance, ac resistance and inductive reactance. These parameters are figures of merit for ground system conductors in that the system with the lowest impedance is the most effective in minimizing noise voltage. Although the welding cable system is probably adequate, the aluminum sheet system provides a higher probability of a successful system design.

Ground-water protection activities of the US Nuclear Regulatory Commission

International Nuclear Information System (INIS)

1987-02-01

This report evaluates the internal consistency of NRC's ground-water protection programs. These programs have evolved consistently with growing public concerns about the significance of ground-water contamination and environmental impacts. Early NRC programs provided for protection of the public health and safety by minimizing releases of radionuclides. More recent programs have included provisions for minimizing releases of nonradiological constituents, mitigating environmental impacts, and correcting ground-water contamination. NRC's ground-water protection programs are categorized according to program areas, including nuclear materials and waste management (NMSS), nuclear reactor operation (NRR), confirmatory research and standards development (RES), inspection and enforcement (IE), and agreement state programs (SP). Based on analysis of existing ground-water protection programs within NRC, the interoffice Ground-water Protection Group has identified several inconsistencies between and within program areas. These inconsistencies include: (1) different definitions of the term ''ground-water,'' (2) variable regulation of nonradiological constituents in ground water, (3) different design periods for ground-water protection, and (4) different scopes and rigor of ground-water assessments. The second inconsistency stems from differences in statutory authority granted to the NRC. The third inconsistency is rationalized by recognizing differences in perceived risks associated with nuclear facilities. The Ground-water Protection Group will document its analysis of the remaining inconsistencies and make recommendations to reconcile or eliminate them in a subsequent report

Hanford Site ground-water monitoring for 1993

International Nuclear Information System (INIS)

Dresel, P.E.; Luttrell, S.P.; Evans, J.C.

1994-09-01

This report presents the results of the Ground-Water Surveillance Project monitoring for calendar year 1993 on the Hanford Site, Washington. Hanford Site operations from 1943 onward produced large quantities of radiological and chemical waste that have impacted ground-water quality on the Site. Monitoring of water levels and ground-water chemistry is performed to track the extent of contamination and trends in contaminant concentrations. The 1993 monitoring was also designed to identify emerging ground-water quality problems. The information obtained is used to verify compliance with applicable environmental regulations and to evaluate remedial actions. Data from other monitoring and characterization programs were incorporated to provide an integrated assessment of Site ground-water quality. Additional characterization of the Site's geologic setting and hydrology was performed to support the interpretation of contaminant distributions. Numerical modeling of sitewide ground-water flow also supported the overall project goals. Water-level monitoring was performed to evaluate ground-water flow directions, to track changes in water levels, and to relate such changes to changes in site disposal practices. Water levels over most of the Hanford Site continued to decline between June 1992 and June 1993. The greatest declines occurred in the 200-West Area. These declines are part of the continued response to the cessation of discharge to U Pond and other disposal facilities. The low permeability in this area which enhanced mounding of waste-water discharge has also slowed the response to the reduction of disposal. Water levels remained nearly constant in the vicinity of B Pond, as a result of continued disposal to the pond. Water levels measured from wells in the unconfined aquifer north and east of the Columbia River indicate that the primary source of recharge is irrigation practices

Hanford Site ground-water monitoring for 1993

Energy Technology Data Exchange (ETDEWEB)

Dresel, P.E.; Luttrell, S.P.; Evans, J.C. [and others

1994-09-01

This report presents the results of the Ground-Water Surveillance Project monitoring for calendar year 1993 on the Hanford Site, Washington. Hanford Site operations from 1943 onward produced large quantities of radiological and chemical waste that have impacted ground-water quality on the Site. Monitoring of water levels and ground-water chemistry is performed to track the extent of contamination and trends in contaminant concentrations. The 1993 monitoring was also designed to identify emerging ground-water quality problems. The information obtained is used to verify compliance with applicable environmental regulations and to evaluate remedial actions. Data from other monitoring and characterization programs were incorporated to provide an integrated assessment of Site ground-water quality. Additional characterization of the Site`s geologic setting and hydrology was performed to support the interpretation of contaminant distributions. Numerical modeling of sitewide ground-water flow also supported the overall project goals. Water-level monitoring was performed to evaluate ground-water flow directions, to track changes in water levels, and to relate such changes to changes in site disposal practices. Water levels over most of the Hanford Site continued to decline between June 1992 and June 1993. The greatest declines occurred in the 200-West Area. These declines are part of the continued response to the cessation of discharge to U Pond and other disposal facilities. The low permeability in this area which enhanced mounding of waste-water discharge has also slowed the response to the reduction of disposal. Water levels remained nearly constant in the vicinity of B Pond, as a result of continued disposal to the pond. Water levels measured from wells in the unconfined aquifer north and east of the Columbia River indicate that the primary source of recharge is irrigation practices.

Strong ground motion of the 2016 Kumamoto earthquake

Science.gov (United States)

Aoi, S.; Kunugi, T.; Suzuki, W.; Kubo, H.; Morikawa, N.; Fujiwara, H.

2016-12-01

The 2016 Kumamoto earthquake that is composed of Mw 6.1 and Mw 7.1 earthquakes respectively occurred in the Kumamoto region at 21:26 on April 14 and 28 hours later at 1:25 on April 16, 2016 (JST). These earthquakes are considered to rupture mainly the Hinagu fault zone for the Mw 6.1 event and the Futagawa fault zone for the Mw 7.1 event, respectively, where the Headquarter for Earthquake Research Promotion performed the long-term evaluation as well as seismic hazard assessment prior to the 2016 Kumamoto earthquake. Strong shakings with seismic intensity 7 in the JMA scale were observed at four times in total: Mashiki town for the Mw 6.1 and Mw 7.1 events, Nishihara village for the Mw 7.1 event, and NIED/KiK-net Mashiki (KMMH16) for the Mw 7.1 event. KiK-net Mashiki (KMMH16) recorded peak ground acceleration more than 1000 cm/s/s, and Nishihara village recorded peak ground velocity more than 250 cm/s. Ground motions were observed wider area for the Mw 7.1 event than the Mw 6.1 event. Peak ground accelerations and peak ground velocities of K-NET/KiK-net stations are consistent with the ground motion prediction equations by Si and Midorikawa (1999). Peak ground velocities at longer distance than 200 km attenuate slowly, which can be attributed to the large Love wave with a dominant period around 10 seconds. 5%-damped pseudo spectral velocity of the Mashiki town shows a peak at period of 1-2 s that exceeds ground motion response of JR Takatori of the 1995 Kobe earthquake and the Kawaguchi town of the 2004 Chuetsu earthquake. 5%-damped pseudo spectral velocity of the Nishihara village shows 350 cm/s peak at period of 3-4 s that is similar to the several stations in Kathmandu basin by Takai et al. (2016) during the 2015 Gorkha earthquake in Nepal. Ground motions at several stations in Oita exceed the ground motion prediction equations due to an earthquake induced by the Mw 7.1 event. Peak ground accelerations of K-NET Yufuin (OIT009) records 90 cm/s/s for the Mw 7

Development of mine explosion ground truth smart sensors

Energy Technology Data Exchange (ETDEWEB)

Taylor, Steven R. [Rocky Mountain Geophysics, Inc., Los Alamos, NM (United States); Harben, Phillip E. [Rocky Mountain Geophysics, Inc., Los Alamos, NM (United States); Jarpe, Steve [Jarpe Data Solutions, Prescott, AZ (United States); Harris, David B. [Deschutes Signal Processing, Maupin, OR (United States)

2015-09-14

Accurate seismo-acoustic source location is one of the fundamental aspects of nuclear explosion monitoring. Critical to improved location is the compilation of ground truth data sets for which origin time and location are accurately known. Substantial effort by the National Laboratories and other seismic monitoring groups have been undertaken to acquire and develop ground truth catalogs that form the basis of location efforts (e.g. Sweeney, 1998; Bergmann et al., 2009; Waldhauser and Richards, 2004). In particular, more GT1 (Ground Truth 1 km) events are required to improve three-dimensional velocity models that are currently under development. Mine seismicity can form the basis of accurate ground truth datasets. Although the location of mining explosions can often be accurately determined using array methods (e.g. Harris, 1991) and from overhead observations (e.g. MacCarthy et al., 2008), accurate origin time estimation can be difficult. Occasionally, mine operators will share shot time, location, explosion size and even shot configuration, but this is rarely done, especially in foreign countries. Additionally, shot times provided by mine operators are often inaccurate. An inexpensive, ground truth event detector that could be mailed to a contact, placed in close proximity (< 5 km) to mining regions or earthquake aftershock regions that automatically transmits back ground-truth parameters, would greatly aid in development of ground truth datasets that could be used to improve nuclear explosion monitoring capabilities. We are developing an inexpensive, compact, lightweight smart sensor unit (or units) that could be used in the development of ground truth datasets for the purpose of improving nuclear explosion monitoring capabilities. The units must be easy to deploy, be able to operate autonomously for a significant period of time (> 6 months) and inexpensive enough to be discarded after useful operations have expired (although this may not be part of our business

Ground assessment methods for nuclear power plant

International Nuclear Information System (INIS)

1985-01-01

It is needless to say that nuclear power plant must be constructed on the most stable and safe ground. Reliable assessment method is required for the purpose. The Ground Integrity Sub-committee of the Committee of Civil Engineering of Nuclear Power Plant started five working groups, the purpose of which is to systematize the assessment procedures including geological survey, ground examination and construction design. The works of working groups are to establishing assessment method of activities of faults, standardizing the rock classification method, standardizing assessment and indication method of ground properties, standardizing test methods and establishing the application standard for design and construction. Flow diagrams for the procedures of geological survey, for the investigation on fault activities and ground properties of area where nuclear reactor and important outdoor equipments are scheduled to construct, were established. And further, flow diagrams for applying investigated results to design and construction of plant, and for determining procedure of liquidification nature of ground etc. were also established. These systematized and standardized methods of investigation are expected to yield reliable data for assessment of construction site of nuclear power plant and lead to the safety of construction and operation in the future. In addition, the execution of these systematized and detailed preliminary investigation for determining the construction site of nuclear power plant will make much contribution for obtaining nation-wide understanding and faith for the project. (Ishimitsu, A.)

α-decay half-lives of some nuclei from ground state to ground state using different nuclear potential

Directory of Open Access Journals (Sweden)

Akrawy Dashty T.

2018-01-01

Full Text Available Theoretical α-decay half-lives of some nuclei from ground state to ground state are calculated using different nuclear potential model including Coulomb proximity potential (CPPM, Royer proximity potential and Broglia and Winther 1991. The calculated values comparing with experimental data, it is observed that the CPPM model is in good agreement with the experimental data.

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

Energy Technology Data Exchange (ETDEWEB)

Levinson, Ronnen Michael [Univ. of California, Berkeley, CA (United States)

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 frequentlyproposed 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 0.25 perturbs the object’s surface temperature by -1 to +2 K. Comparing a tree’s canopy-to-air convection to the reduction in ground-to-air convection induced by tree shading of the ground indicates that the presence of a tree can either increase or decrease solar heating of ground-level air. The tree’s net effect depends on the extent to which solar heating of the canopy is dissipated by evaporation, and on the fraction of air heated by the canopy that flows downward and mixes with the ground-level air. A two-month lysimeter (plant-weighing) experiment was conducted to measure instantaneous rates of water loss from a tree under various conditions of weather and soil-moisture. Calculations of canopy-to-air convection and the reduction of ground-to-air convection based on this data indicate that canopy-induced heating would negate shadowinduced cooling if approximately 45% of the canopy-heated air mixed with ground level air. This critical fraction is comparable to typical downward mixing

Evaluation of permeability of compacted bentonite ground considering heterogeneity by geostatistics

International Nuclear Information System (INIS)

Tanaka, Yukihisa; Nakamura, Kunihiko; Kudo, Kohji; Hironaga, Michihiko; Nakagami, Motonori; Niwase, Kazuhito; Komatsu, Shin-ichi

2007-01-01

The permeability of the bentonite ground as an engineered barrier is possibly designed to the value which is lower than that determined in terms of required performance because of heterogeneous distribution of permeability in the ground, which might be considerable when the ground is created by the compaction method. The effect of heterogeneity in the ground on the permeability of the bentonite ground should be evaluated by overall permeability of the ground, whereas in practice, the effect is evaluated by the distribution of permeability in the ground. Thus, in this study, overall permeability of the bentonite ground is evaluated from the permeability of the bentonite ground is evaluated from the permeability distribution determined using the geostatistical method with the dry density data as well as permeability data of the undisturbed sample recovered from the bentonite ground. Consequently, it was proved through this study that possibility of overestimation of permeability of the bentonite ground can be reduced if the overall permeability is used. (author)

Hot Ground Vibration Tests

Data.gov (United States)

National Aeronautics and Space Administration — Ground vibration tests or modal surveys are routinely conducted to support flutter analysis for subsonic and supersonic vehicles. However, vibration testing...

30 CFR 56.12026 - Grounding transformer and switchgear enclosures.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding transformer and switchgear enclosures... MINES Electricity § 56.12026 Grounding transformer and switchgear enclosures. Metal fencing and metal buildings enclosing transformers and switchgear shall be grounded. ...

30 CFR 77.801-1 - Grounding resistors; continuous current rating.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding resistors; continuous current rating... OF UNDERGROUND COAL MINES Surface High-Voltage Distribution § 77.801-1 Grounding resistors; continuous current rating. The ground fault current rating of grounding resistors shall meet the “extended...

14 CFR Appendix H to Part 141 - Ground Instructor Certification Course

Science.gov (United States)

2010-01-01

... planning; and (6) Classroom training techniques. (c) Ground training for a basic ground instructor..., required under this part, for the following ratings: (a) Ground Instructor—Basic. (b) Ground Instructor...) Ground training must include the following aeronautical knowledge areas: (1) Learning process; (2...

Grounded theory in medical education research: AMEE Guide No. 70.

Science.gov (United States)

Watling, Christopher J; Lingard, Lorelei

2012-01-01

Qualitative research in general and the grounded theory approach in particular, have become increasingly prominent in medical education research in recent years. In this Guide, we first provide a historical perspective on the origin and evolution of grounded theory. We then outline the principles underlying the grounded theory approach and the procedures for doing a grounded theory study, illustrating these elements with real examples. Next, we address key critiques of grounded theory, which continue to shape how the method is perceived and used. Finally, pitfalls and controversies in grounded theory research are examined to provide a balanced view of both the potential and the challenges of this approach. This Guide aims to assist researchers new to grounded theory to approach their studies in a disciplined and rigorous fashion, to challenge experienced researchers to reflect on their assumptions, and to arm readers of medical education research with an approach to critically appraising the quality of grounded theory studies.

Evaluating data worth for ground-water management under uncertainty

Science.gov (United States)

Wagner, B.J.

1999-01-01

A decision framework is presented for assessing the value of ground-water sampling within the context of ground-water management under uncertainty. The framework couples two optimization models-a chance-constrained ground-water management model and an integer-programing sampling network design model-to identify optimal pumping and sampling strategies. The methodology consists of four steps: (1) The optimal ground-water management strategy for the present level of model uncertainty is determined using the chance-constrained management model; (2) for a specified data collection budget, the monitoring network design model identifies, prior to data collection, the sampling strategy that will minimize model uncertainty; (3) the optimal ground-water management strategy is recalculated on the basis of the projected model uncertainty after sampling; and (4) the worth of the monitoring strategy is assessed by comparing the value of the sample information-i.e., the projected reduction in management costs-with the cost of data collection. Steps 2-4 are repeated for a series of data collection budgets, producing a suite of management/monitoring alternatives, from which the best alternative can be selected. A hypothetical example demonstrates the methodology's ability to identify the ground-water sampling strategy with greatest net economic benefit for ground-water management.A decision framework is presented for assessing the value of ground-water sampling within the context of ground-water management under uncertainty. The framework couples two optimization models - a chance-constrained ground-water management model and an integer-programming sampling network design model - to identify optimal pumping and sampling strategies. The methodology consists of four steps: (1) The optimal ground-water management strategy for the present level of model uncertainty is determined using the chance-constrained management model; (2) for a specified data collection budget, the monitoring

Research on Integrated Geophysics Detect Potential Ground Fissure in City

Science.gov (United States)

Qian, R.

2017-12-01

North China confined aquifer lied 70 to 200 meters below the earth's surface has been exploited for several decades, which resulted in confined water table declining and has generated a mass of ground fissure. Some of them has reached the surface and the other is developing. As it is very difficult to stop the ground fissure coming into being, measures of avoiding are often taken. It brings great potential risk to urban architecture and municipal engineering. It is very important to find out specific distribution and characteristic of potential ground fissure in city with high resolution. The ground fissure is concealed, therefor, geophysical method is an important technology to detecting concealed ground fissure. However, it is very difficult to detect the characteristics of the superficial part of ground fissure directly, as it lies dozens of meters below and has only scores of centimeters fault displacement. This paper studies applied ground penetration radar, surface wave and shallow refleciton seismic to detect ground fissure. It sets up model of surface by taking advantage of high resolution of ground penetrating radar data, constrains Reilay wave inversion and improves its resolution. The high resolution reflection seismic is good at detecting the geology structure. The data processing and interpretation technique is developmented to avoid the pitfall and improve the aliability of the rusult. The experiment has been conducted in Shunyi District, Beijing in 2016. 5 lines were settled to collect data of integrated geophysical method. Development zone of concealed ground fissure was found and its ultra shallow layer location was detected by ground penetrating radar. A trial trench of 6 meters in depth was dug and obvious ground fissure development was found. Its upper end was 1.5 meters beneath the earth's surface with displacement of 0.3 meters. The favorable effect of this detection has provided a new way for detecting ground fissure in cities of China, such

Ground Control for Emplacement Drifts for SR

International Nuclear Information System (INIS)

Y. Sun

2000-01-01

This analysis demonstrates that a satisfactory ground control system can be designed for the Yucca Mountain site, and provides the technical basis for the design of ground support systems to be used in repository emplacement and non-emplacement drifts. The repository ground support design was based on analytical methods using acquired computer codes, and focused on the final support systems. A literature review of case histories, including the lessons learned from the design and construction of the ESF, the studies on the seismic damages of underground openings, and the use of rock mass classification systems in the ground support design, was conducted (Sections 6.3.4 and 6.4). This review provided some basis for determining the inputs and methodologies used in this analysis. Stability of the supported and unsupported emplacement and non-emplacement drifts was evaluated in this analysis. The excavation effects (i.e., state of the stress change due to excavation), thermal effects (i.e., due to heat output from waste packages), and seismic effects (i.e., from potential earthquake events) were evaluated, and stress controlled modes of failure were examined for two in situ stress conditions (k 0 =0.3 and 1.0) using rock properties representing rock mass categories of 1 and 5. Variation of rock mass units such as the non-lithophysal (Tptpmn) and lithophysal (Tptpll) was considered in the analysis. The focus was on the non-lithophysal unit because this unit appears to be relatively weaker and has much smaller joint spacing. Therefore, the drift stability and ground support needs were considered to be controlled by the design for this rock unit. The ground support systems for both emplacement and non-emplacement drifts were incorporated into the models to assess their performance under in situ, thermal, and seismic loading conditions. Both continuum and discontinuum modeling approaches were employed in the analyses of the rock mass behavior and in the evaluation of the

The Mirror in the Ground

DEFF Research Database (Denmark)

Shepherd, Nick

An important and original contribution to the study of the archive, The Mirror in the Ground approaches the discipline of archaeology in South Africa from the perspective of an interest in visualities. Author Nick Shepherd argues that it makes sense to talk about an archaeological aesthetics...... at the University of Cape Town, where he convenes a graduate programme on Public Culture and Heritage. The Mirror in the Ground is the first volume in the relaunched Series in Visual Histories, produced by the Centre for Curating the Archive (CCA) at the University of Cape Town....

30 CFR 57.12026 - Grounding transformer and switchgear enclosures.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Grounding transformer and switchgear enclosures... NONMETAL MINES Electricity Surface and Underground § 57.12026 Grounding transformer and switchgear enclosures. Metal fencing and metal buildings enclosing transformers and switchgear shall be grounded. ...

Technology Transfer Opportunities: Automated Ground-Water Monitoring

Science.gov (United States)

Smith, Kirk P.; Granato, Gregory E.

1997-01-01

Introduction A new automated ground-water monitoring system developed by the U.S. Geological Survey (USGS) measures and records values of selected water-quality properties and constituents using protocols approved for manual sampling. Prototypes using the automated process have demonstrated the ability to increase the quantity and quality of data collected and have shown the potential for reducing labor and material costs for ground-water quality data collection. Automation of water-quality monitoring systems in the field, in laboratories, and in industry have increased data density and utility while reducing operating costs. Uses for an automated ground-water monitoring system include, (but are not limited to) monitoring ground-water quality for research, monitoring known or potential contaminant sites, such as near landfills, underground storage tanks, or other facilities where potential contaminants are stored, and as an early warning system monitoring groundwater quality near public water-supply wells.

Development Ground Fault Detecting System for D.C Voltage Line

Energy Technology Data Exchange (ETDEWEB)

Kim Taek Soo; Song Ung Il; Gwon, Young Dong; Lee Hyoung Kee [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

1996-12-31

It is necessary to keep the security of reliability and to maximize the efficiency of maintenance by prompt detection of a D.C feeder ground fault point at the built ed or a building power plants. At present, the most of the power plants are set up the ground fault indicator lamp in the monitor room. If a ground fault occurs on DC voltage feeder, a current through the ground fault relay is adjusted and the lamps have brightened while the current flows the relay coil. In order to develop such a system, it is analyzed a D.C feeder ground circuit theoretically and studied a principles which can determine ground fault point or a polarity discrimination and a phase discrimination of the line. So, the developed system through this principles can compute a resistance ground fault current and a capacitive ground fault current. It shows that the system can defect a ground fault point or a bad insulated line by measuring a power plant D.C feeder insulation resistance at the un interruptible power status, and therefore the power plant could protect an unexpected service interruption . (author). 18 refs., figs.

Nuclear ground state

International Nuclear Information System (INIS)

Negele, J.W.

1975-01-01

The nuclear ground state is surveyed theoretically, and specific suggestions are given on how to critically test the theory experimentally. Detailed results on 208 Pb are discussed, isolating several features of the charge density distributions. Analyses of 208 Pb electron scattering and muonic data are also considered. 14 figures

Is the ground state of Yang-Mills theory Coulombic?

Science.gov (United States)

Heinzl, T.; Ilderton, A.; Langfeld, K.; Lavelle, M.; Lutz, W.; McMullan, D.

2008-08-01

We study trial states modelling the heavy quark-antiquark ground state in SU(2) Yang-Mills theory. A state describing the flux tube between quarks as a thin string of glue is found to be a poor description of the continuum ground state; the infinitesimal thickness of the string leads to UV artifacts which suppress the overlap with the ground state. Contrastingly, a state which surrounds the quarks with non-Abelian Coulomb fields is found to have a good overlap with the ground state for all charge separations. In fact, the overlap increases as the lattice regulator is removed. This opens up the possibility that the Coulomb state is the true ground state in the continuum limit.

Figure-ground mechanisms provide structure for selective attention.

Science.gov (United States)

Qiu, Fangtu T; Sugihara, Tadashi; von der Heydt, Rüdiger

2007-11-01

Attention depends on figure-ground organization: figures draw attention, whereas shapes of the ground tend to be ignored. Recent research has revealed mechanisms for figure-ground organization in the visual cortex, but how these mechanisms relate to the attention process remains unclear. Here we show that the influences of figure-ground organization and volitional (top-down) attention converge in single neurons of area V2 in Macaca mulatta. Although we found assignment of border ownership for attended and for ignored figures, attentional modulation was stronger when the attended figure was located on the neuron's preferred side of border ownership. When the border between two overlapping figures was placed in the receptive field, responses depended on the side of attention, and enhancement was generally found on the neuron's preferred side of border ownership. This correlation suggests that the neural network that creates figure-ground organization also provides the interface for the top-down selection process.

The impact of forest structure and spatial scale on the relationship between ground plot above ground biomass and GEDI lidar waveforms

Science.gov (United States)

Armston, J.; Marselis, S.; Hancock, S.; Duncanson, L.; Tang, H.; Kellner, J. R.; Calders, K.; Disney, M.; Dubayah, R.

2017-12-01

The NASA Global Ecosystem Dynamics Investigation (GEDI) will place a multi-beam waveform lidar instrument on the International Space Station (ISS) to provide measurements of forest vertical structure globally. These measurements of structure will underpin empirical modelling of above ground biomass density (AGBD) at the scale of individual GEDI lidar footprints (25m diameter). The GEDI pre-launch calibration strategy for footprint level models relies on linking AGBD estimates from ground plots with GEDI lidar waveforms simulated from coincident discrete return airborne laser scanning data. Currently available ground plot data have variable and often large uncertainty at the spatial resolution of GEDI footprints due to poor colocation, allometric model error, sample size and plot edge effects. The relative importance of these sources of uncertainty partly depends on the quality of ground measurements and region. It is usually difficult to know the magnitude of these uncertainties a priori so a common approach to mitigate their influence on model training is to aggregate ground plot and waveform lidar data to a coarser spatial scale (0.25-1ha). Here we examine the impacts of these principal sources of uncertainty using a 3D simulation approach. Sets of realistic tree models generated from terrestrial laser scanning (TLS) data or parametric modelling matched to tree inventory data were assembled from four contrasting forest plots across tropical rainforest, deciduous temperate forest, and sclerophyll eucalypt woodland sites. These tree models were used to simulate geometrically explicit 3D scenes with variable tree density, size class and spatial distribution. GEDI lidar waveforms are simulated over ground plots within these scenes using monte carlo ray tracing, allowing the impact of varying ground plot and waveform colocation error, forest structure and edge effects on the relationship between ground plot AGBD and GEDI lidar waveforms to be directly assessed. We

Ground-water contribution to dose from past Hanford Operations

International Nuclear Information System (INIS)

Freshley, M.D.; Thorne, P.D.

1992-08-01

The Hanford Environmental Dose Reconstruction (HEDR) Project is being conducted to estimate radiation doses that populations and individuals could have received from Hanford Site operations from 1944 to the present. Four possible pathways by which radionuclides migrating in ground water on the Hanford Site could have reached the public have been identified: (1) through contaminated ground water migrating to the Columbia River; (2) through wells on or adjacent to the Hanford Site; (3) through wells next to the Columbia River downstream of Hanford that draw some or all of their water from the river (riparian wells); and (4) through atmospheric deposition resulting in contamination of a small watershed that, in turn, results in contamination of a shallow well or spring by transport in the ground water. These four pathways make up the ''ground-water pathway,'' which is the subject of this study. Assessment of the ground-water pathway was performed by (1) reviewing the existing extensive literature on ground water and ground-water monitoring at Hanford and (2) performing calculations to estimate radionuclide concentrations where no monitoring data were collected. Radiation doses that would result from exposure to these radionuclides were calculated

Quaternary ground siting technology of nuclear power plants

International Nuclear Information System (INIS)

Nishi, K.; Kokusho, T.; Iwatate, Y.; Ishida, K.; Honsho, S.; Okamoto, T.; Tohma, J.; Tanaka, Y.; Kanatani, M.

1992-01-01

A seismic stability evaluation method for a nuclear power plant to be located on Quaternary sandy/gravelly ground is discussed herein in terms of a geological and geotechnical survey, a design earthquake motion evaluation and geotechnical seismic stability analyses. The geological and geotechnical exploration tunnel in the rock foundation siting will be difficult in the Quaternary ground siting. Boring, geophysical surveys and soil sampling will play a major role in this case. A design earthquake input spectrum for this siting is proposed to take in account the significant effect of longer period motion on ground stability. Equivalent and non-linear analyses demonstrate the seismic stability of the foundation ground so long as the soil density is high. (author)

Local figure-ground cues are valid for natural images.

Science.gov (United States)

Fowlkes, Charless C; Martin, David R; Malik, Jitendra

2007-06-08

Figure-ground organization refers to the visual perception that a contour separating two regions belongs to one of the regions. Recent studies have found neural correlates of figure-ground assignment in V2 as early as 10-25 ms after response onset, providing strong support for the role of local bottom-up processing. How much information about figure-ground assignment is available from locally computed cues? Using a large collection of natural images, in which neighboring regions were assigned a figure-ground relation by human observers, we quantified the extent to which figural regions locally tend to be smaller, more convex, and lie below ground regions. Our results suggest that these Gestalt cues are ecologically valid, and we quantify their relative power. We have also developed a simple bottom-up computational model of figure-ground assignment that takes image contours as input. Using parameters fit to natural image statistics, the model is capable of matching human-level performance when scene context limited.

The application of grounded theory and symbolic interactionism.

Science.gov (United States)

Jeon, Yun-Hee

2004-09-01

This paper describes the methodological and theoretical context and underpinnings of a study that examined community psychiatric nurses' work with family caregivers of older people with depression. The study used grounded theory research methods, with its theoretical foundations drawn from symbolic interactionism. The aims of the study were to describe and conceptualize the processes involved when community nurses work and interact with family caregivers and to develop an explanatory theory of these processes. This paper begins with an explanation of the rationale for using grounded theory as the method of choice, followed by a discussion of the theoretical underpinnings of the study, including a brief summary of the nature and origins of symbolic interactionism. Key premises of symbolic interactionism regarded as central to the study are outlined and an analytical overview of the grounded theory method is provided. The paper concludes with a commentary on some of the issues and debates in the use of grounded theory in nursing research. The main purpose of this paper is to provide a methodical and critical review of symbolic interactionism and grounded theory that can help readers, particularly those who are intending to use grounded theory, better understand the processes involved in applying this method to their research.

Adaptive attenuation of aliased ground roll using the shearlet transform

Science.gov (United States)

Hosseini, Seyed Abolfazl; Javaherian, Abdolrahim; Hassani, Hossien; Torabi, Siyavash; Sadri, Maryam

2015-01-01

Attenuation of ground roll is an essential step in seismic data processing. Spatial aliasing of the ground roll may cause the overlap of the ground roll with reflections in the f-k domain. The shearlet transform is a directional and multidimensional transform that separates the events with different dips and generates subimages in different scales and directions. In this study, the shearlet transform was used adaptively to attenuate aliased and non-aliased ground roll. After defining a filtering zone, an input shot record is divided into segments. Each segment overlaps adjacent segments. To apply the shearlet transform on each segment, the subimages containing aliased and non-aliased ground roll, the locations of these events on each subimage are selected adaptively. Based on these locations, mute is applied on the selected subimages. The filtered segments are merged together, using the Hanning function, after applying the inverse shearlet transform. This adaptive process of ground roll attenuation was tested on synthetic data, and field shot records from west of Iran. Analysis of the results using the f-k spectra revealed that the non-aliased and most of the aliased ground roll were attenuated using the proposed adaptive attenuation procedure. Also, we applied this method on shot records of a 2D land survey, and the data sets before and after ground roll attenuation were stacked and compared. The stacked section after ground roll attenuation contained less linear ground roll noise and more continuous reflections in comparison with the stacked section before the ground roll attenuation. The proposed method has some drawbacks such as more run time in comparison with traditional methods such as f-k filtering and reduced performance when the dip and frequency content of aliased ground roll are the same as those of the reflections.

Grounded Theory Methodology: Positivism, Hermeneutics, and Pragmatism

Science.gov (United States)

Age, Lars-Johan

2011-01-01

Glaserian grounded theory methodology, which has been widely adopted as a scientific methodology in recent decades, has been variously characterised as "hermeneutic" and "positivist." This commentary therefore takes a different approach to characterising grounded theory by undertaking a comprehensive analysis of: (a) the philosophical paradigms of…

Dynasting Theory: Lessons in learning grounded theory

Directory of Open Access Journals (Sweden)

Johnben Teik-Cheok Loy, MBA, MTS, Ph.D.

2011-06-01

Full Text Available This article captures the key learning lessons gleaned from the author’s experience learning and developing a grounded theory for his doctoral dissertation using the classic methodology as conceived by Barney Glaser. The theory was developed through data gathered on founders and successors of Malaysian Chinese family-own businesses. The main concern for Malaysian Chinese family businesses emerged as dynasting . the building, maintaining, and growing the power and resources of the business within the family lineage. The core category emerged as dynasting across cultures, where founders and successors struggle to transition from traditional Chinese to hybrid cultural and modernized forms of family business from one generation to the next. The key learning lessons were categorized under five headings: (a sorting through different versions of grounded theory, (b educating and managing research stakeholders, (c embracing experiential learning, (d discovering the core category: grounded intuition, and (e recognizing limitations and possibilities.Keywords: grounded theory, learning, dynasting, family business, Chinese

Bipolar cloud-to-ground lightning flash observations

Science.gov (United States)

Saba, Marcelo M. F.; Schumann, Carina; Warner, Tom A.; Helsdon, John H.; Schulz, Wolfgang; Orville, Richard E.

2013-10-01

lightning is usually defined as a lightning flash where the current waveform exhibits a polarity reversal. There are very few reported cases of cloud-to-ground (CG) bipolar flashes using only one channel in the literature. Reports on this type of bipolar flashes are not common due to the fact that in order to confirm that currents of both polarities follow the same channel to the ground, one necessarily needs video records. This study presents five clear observations of single-channel bipolar CG flashes. High-speed video and electric field measurement observations are used and analyzed. Based on the video images obtained and based on previous observations of positive CG flashes with high-speed cameras, we suggest that positive leader branches which do not participate in the initial return stroke of a positive cloud-to-ground flash later generate recoil leaders whose negative ends, upon reaching the branch point, traverse the return stroke channel path to the ground resulting in a subsequent return stroke of opposite polarity.

Review Essay: A Journey through Grounded Theory

Directory of Open Access Journals (Sweden)

Paula Krüger

2007-01-01

Full Text Available In "Constructing Grounded Theory", Kathy CHARMAZ guides the reader through the research process. Starting with a look back at the history of grounded theory, she explains how to gather rich data, code it, write memos, and compose the first draft. Through various examples from her own research CHARMAZ provides the reader not only with a theoretical description of how to construct a grounded theory but also with a way of seeing how new questions emerge from the data and new theory is built from it. She highlights central concepts, definitions, and useful questions, and offers the reader flexible guidelines to design and conduct a research project. Because of this, the book will be very useful for novices as well as for experts and (PhD- students in the late stages of their theses; it is a must-have for everyone who works with/on (constructivist grounded theory. URN: urn:nbn:de:0114-fqs0701256

Search for the QCD ground state

International Nuclear Information System (INIS)

Reuter, M.; Wetterich, C.

1994-05-01

Within the Euclidean effective action approach we propose criteria for the ground state of QCD. Despite a nonvanishing field strength the ground state should be invariant with respect to modified Poincare transformations consisting of a combination of translations and rotations with suitable gauge transformations. We have found candidate states for QCD with four or more colours. The formation of gluon condensates shows similarities with the Higgs phenomenon. (orig.)

Field Evaluation Of Arsenic Transport Across The Ground-Water/Surface Water Interface: Ground-Water Discharge And Iron Oxide Precipitation

Science.gov (United States)

A field investigation was conducted to examine the distribution of arsenic in ground water, surface water, and sediments at a Superfund Site in the northeastern United States (see companion presentation by K. G. Scheckel et al). Ground-water discharge into the study area was cha...

Ground collectors for heat pumps; Grondcollectoren voor warmtepompen

Energy Technology Data Exchange (ETDEWEB)

Van Krevel, A. [Techneco, Leidschendam (Netherlands)

1999-10-01

The dimensioning and cost optimisation of a closed vertical ground collector system has been studied. The so-called Earth Energy Designer (EED) computer software, specially developed for the calculations involved in such systems, proved to be a particularly useful tool. The most significant findings from the first part of the study, 'Heat extraction from the ground', are presented and some common misconceptions about ground collector systems are clarified. 2 refs.

Is the ground state of Yang-Mills theory Coulombic?

OpenAIRE

Heinzl, Thomas; Ilderton, Anton; Langfeld, Kurt; Lavelle, Martin; Lutz, Wolfgang; McMullan, David

2008-01-01

We study trial states modelling the heavy quark-antiquark ground state in SU(2) Yang-Mills theory. A state describing the flux tube between quarks as a thin string of glue is found to be a poor description of the continuum ground state; the infinitesimal thickness of the string leads to UV artifacts which suppress the overlap with the ground state. Contrastingly, a state which surrounds the quarks with non-abelian Coulomb fields is found to have a good overlap with the ground state for all ch...

Earthquake-induced ground failures in Italy from a reviewed database

Science.gov (United States)

Martino, S.; Prestininzi, A.; Romeo, R. W.

2014-04-01

A database (Italian acronym CEDIT) of earthquake-induced ground failures in Italy is presented, and the related content is analysed. The catalogue collects data regarding landslides, liquefaction, ground cracks, surface faulting and ground changes triggered by earthquakes of Mercalli epicentral intensity 8 or greater that occurred in the last millennium in Italy. As of January 2013, the CEDIT database has been available online for public use (http://www.ceri.uniroma1.it/cn/gis.jsp ) and is presently hosted by the website of the Research Centre for Geological Risks (CERI) of the Sapienza University of Rome. Summary statistics of the database content indicate that 14% of the Italian municipalities have experienced at least one earthquake-induced ground failure and that landslides are the most common ground effects (approximately 45%), followed by ground cracks (32%) and liquefaction (18%). The relationships between ground effects and earthquake parameters such as seismic source energy (earthquake magnitude and epicentral intensity), local conditions (site intensity) and source-to-site distances are also analysed. The analysis indicates that liquefaction, surface faulting and ground changes are much more dependent on the earthquake source energy (i.e. magnitude) than landslides and ground cracks. In contrast, the latter effects are triggered at lower site intensities and greater epicentral distances than the other environmental effects.

Brazilian ground beef authentication by multiplex polymerase chain reaction

Directory of Open Access Journals (Sweden)

Andrey Carlos do Sacramento de Oliveira

2018-02-01

Full Text Available ABSTRACT: The aim of the present study was to assess the efficacy ofmultiplex PCR in detecting the adulterationof commercially available ground beefvia addition and/orsubstitution ofground buffalo meat. Experimentally adulterated ground beefsamples were prepared in triplicate, and dilutions of DNA from Bos taurus and Bubalusbubalis were prepared to determine the detection limit of the method. Concurrently, 91 ground meatsamples sold as “ground beef” were collected from differentstores in northern Brazil andanalyzed bymultiplex PCR. Buffalo DNA was detected in 17.5% of the collected ground meat samples.Our results showed that multiplex PCR is an efficient method for detectingthe incorporation of groundbuffalo meatatpercentages ranging from 10 to 100% and the incorporation of beef at percentages ranging from0.1 to 100% intoground meat samples.

Ground temperature estimation through an energy balance method

Energy Technology Data Exchange (ETDEWEB)

Duan, X. [Manitoba Univ., Winnipeg, MB (Canada); Naterer, G.F. [Univ. of Ontario Inst. of Technology, Oshawa, ON (Canada)

2007-07-01

A joint research project by the University of Manitoba and the University of Ontario Institute of Technology (UOIT) is currently examining ground thermal responses to heat conduction within power transmission line towers. The aim of the study is to develop thermal protection alternatives for the freezing and thawing conditions that typically lead to the tilting and heaving of tower foundations. The analysis presented in this paper focused on the temperatures of areas undisturbed by tower foundations. The ground was approximated as a semi-infinite homogenous system with a sinusoidal variation of ground temperature and constant thermophysical properties. Solar radiation and air temperature data were used to develop the sinusoidal profiles. The far-field temperature was modeled using a 1-D transient heat conduction equation. Geothermal gradients were neglected. The energy balance method was used for boundary conditions at the ground surface. Energy components included heat conduction through the ground; heat convection due to wind; net radiative heat transfer; and latent heat transfer due to evaporation. Newton's law of cooling was used to model the convective heat transfer. The model was used to predict ground temperature under varying conditions. Monthly variations of temperature at 2 meters depth were calculated using different evaporation fractions. The model was also used to estimate summer ground temperature at a site in Manitoba. Air temperature, wind velocity and solar radiation data were used. It was suggested that further research is needed to consider the effects of freezing, thawing, and winter snow cover. 2 refs., 1 tab., 2 figs.

Characteristics of lightning leader propagation and ground attachment

Science.gov (United States)

Jiang, Rubin; Qie, Xiushu; Wang, Zhichao; Zhang, Hongbo; Lu, Gaopeng; Sun, Zhuling; Liu, Mingyuan; Li, Xun

2015-12-01

The grounding process and the associated leader behavior were analyzed by using high-speed video record and time-correlated electric field change for 37 natural negative cloud-to-ground flashes. Weak luminous grounded channel was recognized below the downward leader tip in the frame preceding the return stroke, which is inferred as upward connecting leader considering the physical process of lightning attachment, though not directly confirmed by sequential frames. For stepped leader-first return strokes, the upward connecting leaders tend to be induced by those downward leader branches with brighter luminosity and lower channel tip above ground, and they may accomplish the attachment with great possibility. The upward connecting leaders for 2 out of 61 leader-subsequent stroke sequences were captured in the frame prior to the return stroke, exhibiting relatively long channel lengths of 340 m and 105 m, respectively. The inducing downward subsequent leaders were of the chaotic type characterized by irregular electric field pulse train with duration of 0.2-0.3 ms. The transient drop of the high potential difference between stepped leader system and ground when the attachment occurred would macroscopically terminate the propagation of those ungrounded branches while would not effectively prevent the development of the existing space stem systems in the low-conductivity streamer zone apart from the leader tip. When the ungrounded branches are of poor connection with the main stroke channel, their further propagation toward ground would be feasible. These two factors may contribute to the occurrence of multiple grounding within the same leader-return stroke sequence.

IN-SITU BIOREMEDIATION OF CONTAMINATED GROUND WATER

Science.gov (United States)

This document is one in a series of Ground Water Issue papers which have been prepared in response to needs expressed by the Ground Water Forum. It is based on findings from the research community in concert with experience gained at sites undergoing remediation. the intent of th...

40 CFR 264.97 - General ground-water monitoring requirements.

Science.gov (United States)

2010-07-01

... has not been affected by leakage from a regulated unit; (i) A determination of background ground-water...) Represent the quality of ground water passing the point of compliance. (3) Allow for the detection of... elevation each time ground water is sampled. (g) In detection monitoring or where appropriate in compliance...

The Virginia Beach shallow ground-water study

Science.gov (United States)

Johnson, Henry M.

1999-01-01

IntroductionVirginia Beach is a rapidly growing city of more than 425,000 people. Sources of fresh water within the city, however, are limited. Prior to 1998, the Virginia Beach Public Utilities Department met the city's water needs by purchasing treated drinking water from the City of Norfolk. Because Norfolk had to meet its own requirements, the amount of water available to Virginia Beach was limited to about 30 million gallons per day (mgd) and even less during droughts. This water supply was supplemented with ground water from city-owned, community, and private wells. In many parts of the city, however, ground water cannot be used because of high concentrations of chloride, iron, and (or) sulfur, which give the water an unpleasant taste.In early 1998, a pipeline came on-line that can carry up to 45 mgd of water from Lake Gaston to Virginia Beach. The Gaston pipeline has alleviated concerns about water supply and quality for most residents living north of the "Green Line." These residents primarily use ground water only for small-scale domestic activities such as watering lawns, filling ponds and pools, and washing cars. City water and sewer services have been extended beyond the Green Line into the "Transition Area." Residents and businesses south of the Transition Area, however, continue to rely on ground water to meet most of their needs for potable and non-potable water. To help assure a continued, reliable supply of ground water, the U.S. Geological Survey (USGS), in cooperation with the City of Virginia Beach Public Utilities Department, has begun an assessment of the shallow ground-water resources underlying the City of Virginia Beach.

Evaluation of design feature No.20 -- Ground support options

International Nuclear Information System (INIS)

Duan, F.

2000-01-01

Ground support options are primarily evaluated for emplacement drifts while ground support systems for non-emplacement openings such as access mains and ventilation drifts are not evaluated against LADS evaluation criteria in this report. Considerations include functional requirements for ground support, the use of a steel-lined system, and the feasibility of using an unlined ground support system principally with grouted rock bolts for permanent ground support. The feature evaluation also emphasizes the postclosure effects of ground support materials on waste isolation and the preclosure aspects such as durability, maintainability, constructibility, safety, engineering acceptability, and cost. This evaluation is to: (A) Review the existing analyses, reports, and studies regarding this design feature, and compile relevant information on performance characteristics. (B) Develop an appropriate evaluation approach for evaluating ground support options against evaluation criteria provided by the LADS team. (C) Evaluate ground support options not only for their preclosure performance in terms of drift stability, material durability, maintenance, constructibility, and cost, but also for their postclosure performance in terms of chemical effects of ground support materials (i.e., concrete, steel) on waste isolation and radionuclide transport. Specifically, the scope for ground support options evaluation include: (1) all steel-lined drifts (no cementitious materials), (2) unlined drifts with minimum cementitious materials (e.g., grout for rockbolts), and (3) concrete-lined drifts, with the focus on the postclosure acceptability evaluation. In addition, unlined drifts with zero cementitious materials (e.g., use of frictional bolts such as split sets, Swellex bolts) are briefly discussed. (D) Identify candidate ground support systems that have the potential to enhance the repository performance based on the feature evaluation. and (E) Provide conclusions and recommendations

Modeling of earthquake ground motion in the frequency domain

Science.gov (United States)

Thrainsson, Hjortur

In recent years, the utilization of time histories of earthquake ground motion has grown considerably in the design and analysis of civil structures. It is very unlikely, however, that recordings of earthquake ground motion will be available for all sites and conditions of interest. Hence, there is a need for efficient methods for the simulation and spatial interpolation of earthquake ground motion. In addition to providing estimates of the ground motion at a site using data from adjacent recording stations, spatially interpolated ground motions can also be used in design and analysis of long-span structures, such as bridges and pipelines, where differential movement is important. The objective of this research is to develop a methodology for rapid generation of horizontal earthquake ground motion at any site for a given region, based on readily available source, path and site characteristics, or (sparse) recordings. The research includes two main topics: (i) the simulation of earthquake ground motion at a given site, and (ii) the spatial interpolation of earthquake ground motion. In topic (i), models are developed to simulate acceleration time histories using the inverse discrete Fourier transform. The Fourier phase differences, defined as the difference in phase angle between adjacent frequency components, are simulated conditional on the Fourier amplitude. Uniformly processed recordings from recent California earthquakes are used to validate the simulation models, as well as to develop prediction formulas for the model parameters. The models developed in this research provide rapid simulation of earthquake ground motion over a wide range of magnitudes and distances, but they are not intended to replace more robust geophysical models. In topic (ii), a model is developed in which Fourier amplitudes and Fourier phase angles are interpolated separately. A simple dispersion relationship is included in the phase angle interpolation. The accuracy of the interpolation

Proven Innovations and New Initiatives in Ground System Development

Science.gov (United States)

Gunn, Jody M.

2006-01-01

The state-of-the-practice for engineering and development of Ground Systems has evolved significantly over the past half decade. Missions that challenge ground system developers with significantly reduced budgets in spite of requirements for greater and previously unimagined functionality are now the norm. Making the right trades early in the mission lifecycle is one of the key factors to minimizing ground system costs. The Mission Operations Strategic Leadership Team at the Jet Propulsion Laboratory has spent the last year collecting and working through successes and failures in ground systems for application to future missions.

High-altitude electromagnetic pulse environment over the lossy ground

International Nuclear Information System (INIS)

Xie Yanzhao; Wang Zanji

2003-01-01

The electromagnetic field above ground produced by an incident high-altitude electromagnetic pulse plane wave striking the ground plane was described in this paper in terms of the Fresnel reflection coefficients and the numerical FFT. The pulse reflected from the ground plane always cancel the incident field for the horizontal field component, but the reflected field adds to the incident for the vertical field component. The results of several cases for variations in the observation height, angle of incidence and lossy ground electrical parameters were also presented showing different e-field components above the earth

On the ground state of Yang-Mills theory

OpenAIRE

Bakry, Ahmed S.; Leinweber, Derek B.; Williams, Anthony G.

2011-01-01

We investigate the overlap of the ground state meson potential with sets of mesonic-trial wave functions corresponding to different gluonic distributions. We probe the transverse structure of the flux tube through the creation of non-uniform smearing profiles for the string of glue connecting two color sources in Wilson loop operator. The non-uniformly UV-regulated flux-tube operators are found to optimize the overlap with the ground state and display interesting features in the ground state ...

On the ground state of Yang-Mills theory

Science.gov (United States)

Bakry, Ahmed S.; Leinweber, Derek B.; Williams, Anthony G.

2011-08-01

We investigate the overlap of the ground state meson potential with sets of mesonic-trial wave functions corresponding to different gluonic distributions. We probe the transverse structure of the flux tube through the creation of non-uniform smearing profiles for the string of glue connecting two color sources in Wilson loop operator. The non-uniformly UV-regulated flux-tube operators are found to optimize the overlap with the ground state and display interesting features in the ground state overlap.

GPM GROUND VALIDATION CAMPAIGN REPORTS IFLOODS V1

Data.gov (United States)

National Aeronautics and Space Administration — The GPM Ground Validation Campaign Reports IFloodS dataset consists of various reports filed by the scientists during the GPM Ground Validation Iowa Flood Studies...

Ensemble of ground subsidence hazard maps using fuzzy logic

Science.gov (United States)

Park, Inhye; Lee, Jiyeong; Saro, Lee

2014-06-01

Hazard maps of ground subsidence around abandoned underground coal mines (AUCMs) in Samcheok, Korea, were constructed using fuzzy ensemble techniques and a geographical information system (GIS). To evaluate the factors related to ground subsidence, a spatial database was constructed from topographic, geologic, mine tunnel, land use, groundwater, and ground subsidence maps. Spatial data, topography, geology, and various ground-engineering data for the subsidence area were collected and compiled in a database for mapping ground-subsidence hazard (GSH). The subsidence area was randomly split 70/30 for training and validation of the models. The relationships between the detected ground-subsidence area and the factors were identified and quantified by frequency ratio (FR), logistic regression (LR) and artificial neural network (ANN) models. The relationships were used as factor ratings in the overlay analysis to create ground-subsidence hazard indexes and maps. The three GSH maps were then used as new input factors and integrated using fuzzy-ensemble methods to make better hazard maps. All of the hazard maps were validated by comparison with known subsidence areas that were not used directly in the analysis. As the result, the ensemble model was found to be more effective in terms of prediction accuracy than the individual model.

48 CFR 252.228-7001 - Ground and flight risk.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Ground and flight risk... of Provisions And Clauses 252.228-7001 Ground and flight risk. As prescribed in 228.370(b), use the following clause: Ground and Flight Risk (JUN 2010) (a) Definitions. As used in this clause— (1) Aircraft...

Ground-water conditions in Utah, spring of 1995

Science.gov (United States)

Allen, D.V.; Steiger, J.I.; Sory, J.D.; Garrett, R.B.; Burden, Carole B.; Danner, M.R.; Herbert, L.R.; Gerner, S.J.; Slaugh, B.A.; Swenson, R.L.; Howells, J.H.; Christiansen, H.K.; Bagley, A.D.

1995-01-01

This is the thirty-second in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Department of Natural Resources, Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions.This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, related changes in precipitation and streamflow, and chemical quality of water. Supplementary data, such as maps showing water-level contours, are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions.This report includes individual discussions of selected significant areas of ground-water development in the State for calendar year 1994. Much of the reported data were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Divisions of Water Rights and Water Resources.

Analytic game—theoretic approach to ground-water extraction

Science.gov (United States)

Loáiciga, Hugo A.

2004-09-01

The roles of cooperation and non-cooperation in the sustainable exploitation of a jointly used groundwater resource have been quantified mathematically using an analytical game-theoretic formulation. Cooperative equilibrium arises when ground-water users respect water-level constraints and consider mutual impacts, which allows them to derive economic benefits from ground-water indefinitely, that is, to achieve sustainability. This work shows that cooperative equilibrium can be obtained from the solution of a quadratic programming problem. For cooperative equilibrium to hold, however, enforcement must be effective. Otherwise, according to the commonized costs-privatized profits paradox, there is a natural tendency towards non-cooperation and non-sustainable aquifer mining, of which overdraft is a typical symptom. Non-cooperative behavior arises when at least one ground-water user neglects the externalities of his adopted ground-water pumping strategy. In this instance, water-level constraints may be violated in a relatively short time and the economic benefits from ground-water extraction fall below those obtained with cooperative aquifer use. One example illustrates the game theoretic approach of this work.

The IXV Ground Segment design, implementation and operations

Science.gov (United States)

Martucci di Scarfizzi, Giovanni; Bellomo, Alessandro; Musso, Ivano; Bussi, Diego; Rabaioli, Massimo; Santoro, Gianfranco; Billig, Gerhard; Gallego Sanz, José María

2016-07-01

The Intermediate eXperimental Vehicle (IXV) is an ESA re-entry demonstrator that performed, on the 11th February of 2015, a successful re-entry demonstration mission. The project objectives were the design, development, manufacturing and on ground and in flight verification of an autonomous European lifting and aerodynamically controlled re-entry system. For the IXV mission a dedicated Ground Segment was provided. The main subsystems of the IXV Ground Segment were: IXV Mission Control Center (MCC), from where monitoring of the vehicle was performed, as well as support during pre-launch and recovery phases; IXV Ground Stations, used to cover IXV mission by receiving spacecraft telemetry and forwarding it toward the MCC; the IXV Communication Network, deployed to support the operations of the IXV mission by interconnecting all remote sites with MCC, supporting data, voice and video exchange. This paper describes the concept, architecture, development, implementation and operations of the ESA Intermediate Experimental Vehicle (IXV) Ground Segment and outlines the main operations and lessons learned during the preparation and successful execution of the IXV Mission.

Effect of electrode shape on grounding resistances - Part 1

DEFF Research Database (Denmark)

Ingeman-Nielsen, Thomas; Tomaskovicova, Sonia; Dahlin, Torleif

2016-01-01

Electrode grounding resistance is a major factor affecting measurement quality in electric resistivity tomography (ERT) measurements for cryospheric applications. Still, little information is available on grounding resistances in the geophysical literature, mainly because it is difficult to measure....... The focus-one protocol is a new method for estimating single electrode grounding resistances by measuring the resistance between a single electrode in an ERT array and all the remaining electrodes connected in parallel. For large arrays, the measured resistance is dominated by the grounding resistance...... of the electrode under test, the focus electrode. We have developed an equivalent circuit model formulation for the resistance measured when applying the focus-one protocol. Our model depends on the individual grounding resistances of the electrodes of the array, the mutual resistances between electrodes...

Ground ice and hydrothermal ground motions on aufeis plots of river valleys

Directory of Open Access Journals (Sweden)

V. R. Alekseev

2015-01-01

Full Text Available Localized groundwater outflow and layered freezing of them in forms of large ice clusters on the surface creates specific conditions for energy and mass exchange in the «atmosphere–soil–lithosphere» system. In winter, the soil temperature profile is essentially deformed due to heat emission by the aufeis layer of water at its freezing that forms a specific thermocline layer. Deformation of the temperature profile, gradually decreasing, moves down the cross-section and disappearing at the interface between frozen and thawed rocks. Magnitude and number of the temperature deviations from a «normal» state depends on the heat storage of the aufeis-forming waters and on the number of outflows at a given point. The thermocline formation changes conditions of freezing for underlying ground layers together with mechanism of ice saturation of them, and that results in formation of two-layer ice-ground complexes (IGC which differ drastically from cryogenic features in adjacent parts of the valley. Analysis of genetic characteristics and relation of components of the surface and subsurface layers allowed identification of seven types of the aufeis IGC: massive-segregation, cement-basal, layered-segregation, basal-segregation, vacuum-filtration, pressureinjection, and fissure-vein. Yearly formation and destruction of aufeises and subsurface ices is accompanied by a sequence of particularly hazardous geodynamical phenomena, among which the most important are winter flooding of territories, layered freezing of water, ground heaving, thermokarst, and thermoerosion. Combination of these processes may cause a rapid (often unexpected reconfiguration of channels of both surface and subsurface runoff, abrupt uplifts and subsidences of the surface, and decompaction and «shaking-up» of seasonally thawing and seasonally freezing rocks, which may create exceptionally unfavorable conditions for construction and operation of engineering structures. Aufeis plots

Longevity of Emplacement Drift Ground Support Materials

International Nuclear Information System (INIS)

Tang, D.

2000-01-01

The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for selection of materials for ground support that will function throughout the preclosure period. The Development Plan (DP) for this analysis is given in CRWMS M and O (Civilian Radioactive Waste Management System Management and Operating Contractor) (1999a). The candidate materials for ground support are steel (carbon steel, ductile cast iron, galvanized steel, and stainless steel, etc.) and cement. Steel will mainly be used for steel sets, lagging, channels, rock bolts, and wire mesh. Cement usage is only considered in the case of grouted rock bolts. The candidate materials for the invert structure are steel and crushed rock ballast. The materials shall be evaluated for the repository emplacement drift environment under a specific thermal loading condition based on the proposed License Application Design Selection (LADS) design. The analysis consists of the following tasks: (1) Identify factors affecting the longevity of ground control materials for use in emplacement drifts. (2) Review existing documents concerning behavior of candidate ground control materials during the preclosure period. The major criteria to be considered for steel are mechanical and thermal properties, and durability, of which corrosion is the most important concern. (3) Evaluate the available results and develop recommendations for material(s) to be used

Informed Grounded Theory

Science.gov (United States)

Thornberg, Robert

2012-01-01

There is a widespread idea that in grounded theory (GT) research, the researcher has to delay the literature review until the end of the analysis to avoid contamination--a dictum that might turn educational researchers away from GT. Nevertheless, in this article the author (a) problematizes the dictum of delaying a literature review in classic…

Ground water in the Piedmont upland of central Maryland

Science.gov (United States)

Richardson, Claire A.

1982-01-01

This report, describing ground-water occurrence in a 130-square-mile area of the central Maryland Piedmont, was originally designed for use by the U.S. Environmental Protection Agency in replying to a request for designation of the aquifers to be the sole or principal source of ground water. However, the information contained in the report is pertinent to other crystalline-rock areas as well. The study area is underlain chiefly by crystalline rocks and partly by unaltered sandstones and siltstones. The ground water is derived from local precipitation and generally occurs under water-table conditions. Its movement is restricted by the lack of interconnected openings, and most ground water occurs within 300 feet of the land surface. Hydrographs indicate no long-term change in ground-water storage. A few wells yield more than 100 gallons per minute, but about 70 percent of 286 inventoried wells yield 10 gallons per minute or less; most specific capacities are less than 1.0 gallon per minute per foot. The ground-water quality is generally satisfactory without treatment, and there are no known widespread pollution problems. Estimated daily figures on ground-water use are as follows: 780,000 gallons for domestic purposes; 55,000, for commercial purposes; and 160,000, for public supply. Although part of the area is served by an existing surface-water supply and could be served by possible extension of it and of other public-supply water mains, much of the rural population is dependent on the ground water available from private wells tapping the single aquifer that underlies any given location. Neither the ground-water conditions nor this dependence on individual wells is unique to the study area, but, rather, applies to the entire Piedmont province.

Developing and implementing institutional controls for ground water remediation

International Nuclear Information System (INIS)

Ulland, L.M.; Cooper, M.G.

1995-01-01

The US DOE has initiated its Ground Water Project as the second phase of the Uranium Mill Tailings Remedial Action (UMTRA) Project authorized under the Uranium Mill Tailings Radiation Control Act (UMTRCA). In the Ground Water Project, the DOE must reduce risk from ground water contaminated by uranium mill processing activities at 24 inactive processing sites by meeting the US EPA standards. The UMTRCA also requires consistency with federal statutes such as the Resource Conservation and Recovery Act (RCRA). The use of institutional controls to reduce risk from contaminated ground water is one element of compliance with standards and the protection of public health and the environment. Institutional controls are active or passive measures that reduce exposure to risks by preventing intrusion or restricting direct access to an area, or restricting access to the contamination through secondary means. Because of inconsistent regulations and multi-party authorities for ground water management, the key to selecting and implementing effective institutional controls lies with developing a consensus between the parties responsible for ground water remediation; those with authority to implement, monitor, and maintain institutional controls; and those facing the risks from contaminated ground water. These parties must develop a consensus for an institutional control program that meets minimum regulatory requirements and protects public health and the environment. Developing consensus and implementing a successful institutional controls program was achieved by the DOE during the cleanup of uranium mill tailings. An effective institutional controls program can also be developed to protect against risks from contaminated ground water. Consensus building and information transmission are the critical elements of an institutional control program that protects human health and the environment from risks associated with ground water contamination

Near-Field Ground Motion Modal versus Wave Propagation Analysis

Directory of Open Access Journals (Sweden)

Artur Cichowicz

2010-01-01

Full Text Available The response spectrum generally provides a good estimate of the global displacement and acceleration demand of far-field ground motion on a structure. However, it does not provide accurate information on the local shape or internal deformation of the response of the structure. Near-field pulse-like ground motion will propagate through the structure as waves, causing large, localized deformation. Therefore, the response spectrum alone is not a sufficient representation of near-field ground motion features. Results show that the drift-response technique based on a continuous shear-beam model has to be employed here to estimate structure-demand parameters when structure is exposed to the pulse like ground motion. Conduced modeling shows limited applicability of the drift spectrum based on the SDOF approximation. The SDOF drift spectrum approximation can only be applied to structures with smaller natural periods than the dominant period of the ground motion. For periods larger than the dominant period of ground motion the SDOF drift spectra model significantly underestimates maximum deformation. Strong pulse-type motions are observed in the near-source region of large earthquakes; however, there is a lack of waveforms collected from small earthquakes at very close distances that were recorded underground in mines. The results presented in this paper are relevant for structures with a height of a few meters, placed in an underground excavation. The strong ground motion sensors recorded mine-induced earthquakes in a deep gold mine, South Africa. The strongest monitored horizontal ground motion was caused by an event of magnitude 2 at a distance of 90 m with PGA 123 m/s2, causing drifts of 0.25%–0.35%. The weak underground motion has spectral characteristics similar to the strong ground motion observed on the earth's surface; the drift spectrum has a maximum value less than 0.02%.

Grounding for safety

Energy Technology Data Exchange (ETDEWEB)

Prud' homme, P. [Hydro-Quebec, Montreal, PQ (Canada). TransEnergie Div.

2006-07-01

The importance of providing electrical grounds as a safety issue in the design of power transmission lines was discussed. Power transmission lines extend over several thousands of kilometers crossing various environments, including communities where electric utilities encourage the use of transmission rights-of-way passages for uses such as bicycle paths. In recent years, many new residential communities have been built at the border of power transmission rights-of-ways or substations. In view of this emerging trend, and the fact that internal statistics indicate that lightning strikes are responsible of about 50 to 60 per cent of transmission line faults, electric utilities are obligated to verify if their installations are safe. Hydro-Quebec TransEnergie's view on this subject was presented along with a review of international standards to determine if limits for touch voltage, step voltage and transferred potential close to transmission lines have been established by the international community. A variety of mitigation measures to control the increase in ground potential in the event of electrical faults were also proposed. tabs., figs.

From Darwin to constructivism: the evolution of grounded theory.

Science.gov (United States)

Hall, Helen; Griffiths, Debra; McKenna, Lisa

2013-01-01

To explore the evolution of grounded theory and equip the reader with a greater understanding of the diverse conceptual positioning that is evident in the methodology. Grounded theory was developed during the modernist phase of research to develop theories that are derived from data and explain human interaction. Its philosophical foundations derive from symbolic interactionism and were influenced by a range of scholars including Charles Darwin and George Mead. Rather than a rigid set of rules and procedures, grounded theory is a way of conceptualising data. Researchers demonstrate a range of perspectives and there is significant variation in the way the methodology is interpreted and executed. Some grounded theorists continue to align closely with the original post-positivist view, while others take a more constructivist approach. Although the diverse interpretations accommodate flexibility, they may also result in confusion. The grounded theory approach enables researchers to align to their own particular world view and use methods that are flexible and practical. With an appreciation of the diverse philosophical approaches to grounded theory, researchers are enabled to use and appraise the methodology more effectively.

Evaluation of stability of foundation ground during earthquake, (5)

International Nuclear Information System (INIS)

Nishi, Koh-ichi; Kanatani, Mamoru

1987-01-01

The Central Research Institute of Electric Power Industry advances the research on the method of evaluating foundation grounds from the standpoint of developing in-situ ground survey testing method and the method of evaluating mechanical properties in the studies on the technology for siting nuclear power stations on Quaternary grounds. The newly developed analytical technique on ground stability by the results of the analytical method for equivalent linear response was already reported. In this paper, the analytical method for nonlinear response to investigate into the more detailed behavior of ground due to strong earthquake motion is reported. In particular, the constitutive relation based on elastoplasticity was newly proposed in order to represent the deformation behavior during cyclic loading, and the examples of its application to the response of horizontally leveled sandy ground to earthquake are described. The dialatancy characteristics of soil are constituted by yield function, plastic potential functioin and hardening function. The material constants in proposed constitutive relation are easily determined by laboratory tests. One-dimensional response analysis was conducted, using the constitutive relation. (Kako, I.)

The ShakeOut earthquake source and ground motion simulations

Science.gov (United States)

Graves, R.W.; Houston, Douglas B.; Hudnut, K.W.

2011-01-01

The ShakeOut Scenario is premised upon the detailed description of a hypothetical Mw 7.8 earthquake on the southern San Andreas Fault and the associated simulated ground motions. The main features of the scenario, such as its endpoints, magnitude, and gross slip distribution, were defined through expert opinion and incorporated information from many previous studies. Slip at smaller length scales, rupture speed, and rise time were constrained using empirical relationships and experience gained from previous strong-motion modeling. Using this rupture description and a 3-D model of the crust, broadband ground motions were computed over a large region of Southern California. The largest simulated peak ground acceleration (PGA) and peak ground velocity (PGV) generally range from 0.5 to 1.0 g and 100 to 250 cm/s, respectively, with the waveforms exhibiting strong directivity and basin effects. Use of a slip-predictable model results in a high static stress drop event and produces ground motions somewhat higher than median level predictions from NGA ground motion prediction equations (GMPEs).

Regional analysis of ground and above-ground climate. Part I. Regional suitability of earth-tempering practices: summary and conclusions. Part II. Bioclimatic data

Energy Technology Data Exchange (ETDEWEB)

Labs, K.

The regional suitability of underground construction as a climate-control technique is discussed with reference to (1) a bioclimatic analysis of long-term weather data for 29 locations in the United States to determine appropriate above-ground climate-control techniques, (2) a data base of synthesized ground temperatures for the coterminous United States, and (3) monthly dewpoint ground temperature comparisons for identifying the relative likelihood of condensation, from one region to another. It is concluded that the suitability of earth tempering as a practice and of specific earth-sheltered design stereotypes varies geographically. While the subsurface almost always provides a thermal advantage on its own terms when compared to above-ground climatic data, it can, nonetheless, compromise the effectiveness of other, regionally more important climate-control techniques. Also contained in the report are reviews of above- and below-ground climate mapping schemes related to human comfort and architectural design, and a detailed description of a theoretical model of ground temperature, heat flow, and heat storage in the ground. Strategies of passive climate control are presented in a discussion of the building bioclimatic analysis procedure which has been applied in a computer analysis of 30 years of weather data for each of 29 locations in the United States. 3 references, 12 figures, 14 tables.

Transforming high-dimensional potential energy surfaces into sum-of-products form using Monte Carlo methods

Science.gov (United States)

Schröder, Markus; Meyer, Hans-Dieter

2017-08-01

We propose a Monte Carlo method, "Monte Carlo Potfit," for transforming high-dimensional potential energy surfaces evaluated on discrete grid points into a sum-of-products form, more precisely into a Tucker form. To this end we use a variational ansatz in which we replace numerically exact integrals with Monte Carlo integrals. This largely reduces the numerical cost by avoiding the evaluation of the potential on all grid points and allows a treatment of surfaces up to 15-18 degrees of freedom. We furthermore show that the error made with this ansatz can be controlled and vanishes in certain limits. We present calculations on the potential of HFCO to demonstrate the features of the algorithm. To demonstrate the power of the method, we transformed a 15D potential of the protonated water dimer (Zundel cation) in a sum-of-products form and calculated the ground and lowest 26 vibrationally excited states of the Zundel cation with the multi-configuration time-dependent Hartree method.

Level energies, lifetimes and radiative rates in the 4p44d configurations of bromine-like ions

Science.gov (United States)

Singh, A. K.; Aggarwal, Sunny; Mohan, Man

2013-09-01

Energy levels, lifetimes and wavefunction compositions have been computed for all levels of odd parity 4s24p5 ground configuration as well as 4s4p6 and 4s24p44d even parity excited configurations in Br-like Sr IV, Y V, Zr VI, Nb VII and Mo VIII. Transition probabilities, oscillator strengths and line strengths for the electric dipole (E1) transition from the 4s24p5 configuration have been obtained using the multiconfiguration Dirac-Fock approach. Correlations within the n = 4 complex, Breit and quantum electrodynamics effects have been included. We make a detailed comparison of our results with those of other numerical methods and experiments to assess the quality of our results. Good agreement is observed between our results and those obtained using different approaches confirm the quality of our results. Further, we have also predicted new atomic data that were not available so far and are yet to be observed.

Simulation of Ground-Water Flow and Effects of Ground-Water Irrigation on Base Flow in the Elkhorn and Loup River Basins, Nebraska

Science.gov (United States)

Peterson, Steven M.; Stanton, Jennifer S.; Saunders, Amanda T.; Bradley, Jesse R.

2008-01-01

Irrigated agriculture is vital to the livelihood of communities in the Elkhorn and Loup River Basins in Nebraska, and ground water is used to irrigate most of the cropland. Concerns about the sustainability of ground-water and surface-water resources have prompted State and regional agencies to evaluate the cumulative effects of ground-water irrigation in this area. To facilitate understanding of the effects of ground-water irrigation, a numerical computer model was developed to simulate ground-water flow and assess the effects of ground-water irrigation (including ground-water withdrawals, hereinafter referred to as pumpage, and enhanced recharge) on stream base flow. The study area covers approximately 30,800 square miles, and includes the Elkhorn River Basin upstream from Norfolk, Nebraska, and the Loup River Basin upstream from Columbus, Nebraska. The water-table aquifer consists of Quaternary-age sands and gravels and Tertiary-age silts, sands, and gravels. The simulation was constructed using one layer with 2-mile by 2-mile cell size. Simulations were constructed to represent the ground-water system before 1940 and from 1940 through 2005, and to simulate hypothetical conditions from 2006 through 2045 or 2055. The first simulation represents steady-state conditions of the system before anthropogenic effects, and then simulates the effects of early surface-water development activities and recharge of water leaking from canals during 1895 to 1940. The first simulation ends at 1940 because before that time, very little pumpage for irrigation occurred, but after that time it became increasingly commonplace. The pre-1940 simulation was calibrated against measured water levels and estimated long-term base flow, and the 1940 through 2005 simulation was calibrated against measured water-level changes and estimated long-term base flow. The calibrated 1940 through 2005 simulation was used as the basis for analyzing hypothetical scenarios to evaluate the effects of

Cleanup Verification Package for the 618-2 Burial Ground

Energy Technology Data Exchange (ETDEWEB)

W. S. Thompson

2006-12-28

This cleanup verification package documents completion of remedial action for the 618-2 Burial Ground, also referred to as Solid Waste Burial Ground No. 2; Burial Ground No. 2; 318-2; and Dry Waste Burial Site No. 2. This waste site was used primarily for the disposal of contaminated equipment, materials and laboratory waste from the 300 Area Facilities.

Cleanup Verification Package for the 618-2 Burial Ground

International Nuclear Information System (INIS)

Thompson, W.S.

2006-01-01

This cleanup verification package documents completion of remedial action for the 618-2 Burial Ground, also referred to as Solid Waste Burial Ground No. 2; Burial Ground No. 2; 318-2; and Dry Waste Burial Site No. 2. This waste site was used primarily for the disposal of contaminated equipment, materials and laboratory waste from the 300 Area Facilities

Study on parameter identification and control of ground temperature

International Nuclear Information System (INIS)

Kojima, Keiichi; Suzuki, Seiichi; Kawahara, Mutsuto.

1995-01-01

A numerical thermal management system for ground structure is presented. The system consists of two parts, i.e. the identification analysis of the thermal conductivity and the thermal control analysis for the ground. The former is carried out by using the nonlinear least squares method and the latter is based on the optimal control theory. The formulations of these methods are presented and they are applied to an laboratory test. A reasonable thermal conductivity of the ground is identified by parameter estimation method and the ground temperature is actually controled as illustrated by numerical and experimental study. (author)

Water budget for SRP burial ground area

International Nuclear Information System (INIS)

Hubbard, J.E.; Emslie, R.H.

1984-01-01

Radionuclide migration from the SRP burial ground for solid low-level waste has been studied extensively. Most of the buried radionuclides are fixed on the soil and show negligible movement. The major exception is tritium, which when leached from the waste by percolating rainfall, forms tritiated water and moves with the groundwater. The presence of tritium has been useful in tracing groundwater flow paths to outcrop. A subsurface tritium plume moving from the southwest corner of the burial ground toward an outcrop near Four Mile Creek has been defined. Groundwater movement is so slow that much of the tritium decays before reaching the outcrop. The burial ground tritium plume defined to date is virtually all in the uppermost sediment layer, the Barnwell Formation. The purpose of the study reported in this memorandum was to investigate the hypothesis that deeper flow paths, capable of carrying substantial amounts of tritium, may exist in the vicinity of the burial ground. As a first step in seeking deeper flow paths, a water budget was constructed for the burial ground site. The water budget, a materials balance used by hydrologists, is expressed in annual area inches of rainfall. Components of the water budget for the burial ground area were analyzed to determine whether significant flow paths may exist below the tan clay. Mean annual precipitation was estimated as 47 inches, with evapotranspiration, run-off, and groundwater recharge estimated as 30, 2, and 15 inches, respectively. These estimates, when combined with groundwater discharge data, suggest that 5 inches of the groundwater recharge flow above the tan clay and that 10 inches flow below the tan clay. Therefore, two-thirds of the groundwater recharge appears to follow flow paths that are deeper than those previously found. 13 references, 10 figures, 5 tables

Illumination compensation in ground based hyperspectral imaging

Science.gov (United States)

Wendel, Alexander; Underwood, James

2017-07-01

Hyperspectral imaging has emerged as an important tool for analysing vegetation data in agricultural applications. Recently, low altitude and ground based hyperspectral imaging solutions have come to the fore, providing very high resolution data for mapping and studying large areas of crops in detail. However, these platforms introduce a unique set of challenges that need to be overcome to ensure consistent, accurate and timely acquisition of data. One particular problem is dealing with changes in environmental illumination while operating with natural light under cloud cover, which can have considerable effects on spectral shape. In the past this has been commonly achieved by imaging known reference targets at the time of data acquisition, direct measurement of irradiance, or atmospheric modelling. While capturing a reference panel continuously or very frequently allows accurate compensation for illumination changes, this is often not practical with ground based platforms, and impossible in aerial applications. This paper examines the use of an autonomous unmanned ground vehicle (UGV) to gather high resolution hyperspectral imaging data of crops under natural illumination. A process of illumination compensation is performed to extract the inherent reflectance properties of the crops, despite variable illumination. This work adapts a previously developed subspace model approach to reflectance and illumination recovery. Though tested on a ground vehicle in this paper, it is applicable to low altitude unmanned aerial hyperspectral imagery also. The method uses occasional observations of reference panel training data from within the same or other datasets, which enables a practical field protocol that minimises in-field manual labour. This paper tests the new approach, comparing it against traditional methods. Several illumination compensation protocols for high volume ground based data collection are presented based on the results. The findings in this paper are

Seven methods to measure ground moisture

International Nuclear Information System (INIS)

Anon.

1983-01-01

The correct irrigation methods are of great importance to the deciduous fruit grower. The article discusses seven methods for the measuring of ground humidity. These methods are based on gravimetry, electric resistance, gamma attenuation, neutron humidity measurement, tensiometers and a study of the correlation between ground humidity and water evaporation. At this stage, the last technique is regarded as the most practicle method. Neutron moisture gages might be used if adhered to the regulations of NUCOR

Shielding and grounding in large detectors

International Nuclear Information System (INIS)

Radeka, V.

1998-09-01

Prevention of electromagnetic interference (EMI), or ''noise pickup,'' is an important design aspect in large detectors in accelerator environments. Shielding effectiveness as a function of shield thickness and conductivity vs the type and frequency of the interference field is described. Noise induced in transmission lines by ground loop driven currents in the shield is evaluated and the importance of low shield resistance is emphasized. Some measures for prevention of ground loops and isolation of detector-readout systems are discussed

40 CFR 257.3-4 - Ground water.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Ground water. 257.3-4 Section 257.3-4... and Practices § 257.3-4 Ground water. (a) A facility or practice shall not contaminate an underground drinking water source beyond the solid waste boundary or beyond an alternative boundary specified in...

Soil and ground-water remediation techniques

International Nuclear Information System (INIS)

Beck, P.

1996-01-01

Urban areas typically contain numerous sites underlain by soils or ground waters which are contaminated to levels that exceed clean-up guidelines and are hazardous to public health. Contamination most commonly results from the disposal, careless use and spillage of chemicals, or the historic importation of contaminated fill onto properties undergoing redevelopment. Contaminants of concern in soil and ground water include: inorganic chemicals such as heavy metals; radioactive metals; salt and inorganic pesticides, and a range of organic chemicals included within petroleum fuels, coal tar products, PCB oils, chlorinated solvents, and pesticides. Dealing with contaminated sites is a major problem affecting all urban areas and a wide range of different remedial technologies are available. This chapter reviews the more commonly used methods for ground-water and soil remediation, paying particular regard to efficiency and applicability of specific treatments to different site conditions. (author). 43 refs., 1 tab., 27 figs

A new digital ground-fault protection system for generator-transformer unit

Energy Technology Data Exchange (ETDEWEB)

Zielichowski, Mieczyslaw; Szlezak, Tomasz [Institute of Electrical Power Engineering, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50370 Wroclaw (Poland)

2007-08-15

Ground faults are one of most often reasons of damages in stator windings of large generators. Under certain conditions, as a result of ground-fault protection systems maloperation, ground faults convert into high-current faults, causing severe failures in power system. Numerous publications in renowned journals and magazines testify about ground-fault matter importance and problems reported by exploitators confirm opinions, that some issues concerning ground-fault protection of large generators have not been solved yet or have been solved insufficiently. In this paper a new conception of a digital ground-fault protection system for stator winding of large generator was proposed. The process of intermittent arc ground fault in stator winding has been briefly discussed and actual ground-fault voltage waveforms were presented. A new relaying algorithm, based on third harmonic voltage measurement was also drawn and the methods of its implementation and testing were described. (author)

A fiber Bragg grating acceleration sensor for ground surveillance

Science.gov (United States)

Jiang, Shaodong; Zhang, Faxiang; Lv, Jingsheng; Ni, Jiasheng; Wang, Chang

2017-10-01

Ground surveillance system is a kind of intelligent monitoring equipment for detecting and tracking the ground target. This paper presents a fiber Bragg grating (FBG) acceleration sensor for ground surveillance, which has the characteristics of no power supply, anti-electromagnetic interference, easy large-scale networking, and small size. Which make it able to achieve the advantage of the ground surveillance system while avoiding the shortcoming of the electric sensing. The sensor has a double cantilever beam structure with a sensitivity of 1000 pm/g. Field experiment has been carried out on a flood beach to examine the sensor performance. The result shows that the detection distance on the walking of personnel reaches 70m, and the detection distance on the ordinary motor vehicle reaches 200m. The performance of the FBG sensor can satisfy the actual needs of the ground surveillance system.

Figure-Ground Processing: A Reassessment of Gelb and Granit.

Science.gov (United States)

Nelson, Rolf; Hebda, Nicholas

2018-03-01

In 1923, Adhemar Gelb and Ragnar Granit, two prominent researchers in early Gestalt perceptual theory, reported a lower threshold for detection of a target (a small colored dot) on the ground region of an image than on an adjacent figural region. Although their results had a wide influence on the understanding of figure-ground perception, they are at odds with more recent investigations in which figural regions appear to have a processing advantage over ground regions. The two present studies replicated Gelb and Granit's experiment using a similar figure-ground stimulus albeit with a two-alternative forced choice procedure rather than their original method of adjustment. Experiment 1 found that, contrary to Gelb and Granit's findings, a detection advantage was found for the figural over the ground region. Experiment 2 indicated that explicit contours might have played a role in detection.

Hanford Site ground-water monitoring for 1991

International Nuclear Information System (INIS)

Evans, J.C.; Bryce, R.W.; Bates, D.J.

1992-10-01

The Pacific Northwest Laboratory (PNL) monitors the distribution of radionuclides and other hazardous materials in ground water at the Hanford Site for the US Department of Energy (DOE). This work is performed through the Ground-Water Surveillance Project and is designed to meet the requirements of DOE Order 5400.1 that apply to environmental surveillance and ground-water monitoring (DOE 1988). This annual report discusses results of ground-water monitoring at the Hanford Site during 1991. In addition to the general discussion, the following topics are discussed in detail: (1) carbon tetrachloride in the 200-West Area; (2) cyanide in and north of the 200-East and the 200-West areas; (3) hexavalent chromium contamination in the 100, 200, and 600 areas; (4) trichloroethylene in the vicinity of the Solid Waste Landfill, 100-F Area, and 300 Area; (5) nitrate across the Site; (6) tritium across the Site; and (7) other radionuclide contamination throughout the Site, including gross alpha, gross beta, cobalt-60, strontium-90, technetium-99, iodine-129, cesium-137, uranium, and plutonium

Figure-ground segregation: A fully nonlocal approach.

Science.gov (United States)

Dimiccoli, Mariella

2016-09-01

We present a computational model that computes and integrates in a nonlocal fashion several configural cues for automatic figure-ground segregation. Our working hypothesis is that the figural status of each pixel is a nonlocal function of several geometric shape properties and it can be estimated without explicitly relying on object boundaries. The methodology is grounded on two elements: multi-directional linear voting and nonlinear diffusion. A first estimation of the figural status of each pixel is obtained as a result of a voting process, in which several differently oriented line-shaped neighborhoods vote to express their belief about the figural status of the pixel. A nonlinear diffusion process is then applied to enforce the coherence of figural status estimates among perceptually homogeneous regions. Computer simulations fit human perception and match the experimental evidence that several cues cooperate in defining figure-ground segregation. The results of this work suggest that figure-ground segregation involves feedback from cells with larger receptive fields in higher visual cortical areas. Copyright © 2015 Elsevier Ltd. All rights reserved.

Modal-pushover-based ground-motion scaling procedure

Science.gov (United States)

Kalkan, Erol; Chopra, Anil K.

2011-01-01

Earthquake engineering is increasingly using nonlinear response history analysis (RHA) to demonstrate the performance of structures. This rigorous method of analysis requires selection and scaling of ground motions appropriate to design hazard levels. This paper presents a modal-pushover-based scaling (MPS) procedure to scale ground motions for use in a nonlinear RHA of buildings. In the MPS method, the ground motions are scaled to match to a specified tolerance, a target value of the inelastic deformation of the first-mode inelastic single-degree-of-freedom (SDF) system whose properties are determined by the first-mode pushover analysis. Appropriate for first-mode dominated structures, this approach is extended for structures with significant contributions of higher modes by considering elastic deformation of second-mode SDF systems in selecting a subset of the scaled ground motions. Based on results presented for three actual buildings-4, 6, and 13-story-the accuracy and efficiency of the MPS procedure are established and its superiority over the ASCE/SEI 7-05 scaling procedure is demonstrated.

Ground-water temperature of the Wyoming quadrangle in central Delaware : with application to ground-water-source heat pumps

Science.gov (United States)

Hodges, Arthur L.

1982-01-01

Ground-water temperature was measured during a one-year period (1980-81) in 20 wells in the Wyoming Quadrangle in central Delaware. Data from thermistors set at fixed depths in two wells were collected twice each week, and vertical temperature profiles of the remaining 18 wells were made monthly. Ground-water temperature at 8 feet below land surface in well Jc55-1 ranged from 45.0 degrees F in February to 70.1 degrees F in September. Temperature at 35 feet below land surface in the same well reached a minimum of 56.0 degrees F in August, and a maximum of 57.8 degrees F in February. Average annual temperature of ground water at 25 feet below land surface in all wells ranged from 54.6 degrees F to 57.8 degrees F. Variations of average temperature probably reflect the presence or absence of forestation in the recharge areas of the wells. Ground-water-source heat pumps supplied with water from wells 30 or more feet below land surface will operate more efficiently in both heating and cooling modes than those supplied with water from shallower depths. (USGS)

Heat pipes for ground heating and cooling

Energy Technology Data Exchange (ETDEWEB)

Vasiliev, L L

1988-01-01

Different versions of heat pipe ground heating and cooling devices are considered. Solar energy, biomass, ground stored energy, recovered heat of industrial enterprises and ambient cold air are used as energy and cold sources. Heat pipe utilization of air in winter makes it possible to design accumulators of cold and ensures deep freezing of ground in order to increase its mechanical strength when building roadways through the swamps and ponds in Siberia. Long-term underground heat storage systems are considered, in which the solar and biomass energy is accumulated and then transferred to heat dwellings and greenhouses, as well as to remove snow from roadways with the help of heat pipes and solar collectors.

Crystalline beam ground state

International Nuclear Information System (INIS)

Wei, Jie; Li, Xiao-Ping; Sessler, A.M.

1993-01-01

In order to employ Molecular Dynamics method, commonly used in condensed matter physics, we have derived the equations of motion for a beam of charged particles in the rotating rest frame of the reference particle. We include in the formalism that the particles are confined by the guiding and focusing magnetic fields, and that they are confined in a conducting vacuum pipe while interacting with each other via a Coulomb force. Numerical simulations has been performed to obtain the equilibrium structure. The effects of the shearing force, centrifugal force, and azimuthal variation of the focusing strength are investigated. It is found that a constant gradient storage ring can not give a crystalline beam, but that an alternating-gradient (AG) structure can. In such a machine the ground state is, except for one-dimensional (1-D) crystals, time-dependent. The ground state is a zero entropy state, despite the time-dependent, periodic variation of the focusing force. The nature of the ground state, similar to that found by Rahman and Schiffer, depends upon the density and the relative focusing strengths in the transverse directions. At low density, the crystal is 1-D. As the density increases, it transforms into various kinds of 2-D and 3-D crystals. If the energy of the beam is higher than the transition energy of the machine, the crystalline structure can not be formed for lack of radial focusing

Crystalline beam ground state

International Nuclear Information System (INIS)

Wei, Jie; Li, Xiao-Ping

1993-01-01

In order to employ molecular dynamics (MD) methods, commonly used in condensed matter physics, we have derived the equations of motion for a beam of charged particles in the rotating rest frame of the reference particle. We include in the formalism that the particles are confined by the guiding and focusing magnetic fields, and that they are confined in a conducting vacuum pipe while interacting with each other via a Coulomb force. Numerical simulations using MD methods has been performed to obtain the equilibrium crystalline beam structure. The effect of the shearing force, centrifugal force, and azimuthal variation of the focusing strength are investigated. It is found that a constant gradient storage ring can not give a crystalline beam, but that an alternating-gradient (AG) structure can. In such a machine the ground state is, except for one-dimensional (1-D) crystals, time dependent. The ground state is a zero entropy state, despite the time-dependent, periodic variation of the focusing force. The nature of the ground state, similar to that found by Schiffer et al. depends upon the density and the relative focusing strengths in the transverse directions. At low density, the crystal is 1-D. As the density increases, it transforms into various kinds of 2-D and 3-D crystals. If the energy of the beam is higher than the transition energy of the machine, the crystalline structure can not be formed for lack of radial focusing

Crystalline beam ground state

International Nuclear Information System (INIS)

Wei, J.; Li, X.P.

1993-01-01

In order to employ the Molecular Dynamics method, commonly used in condensed matter physics, the authors have derived the equations of motion for a beam of charged particles in the rotating rest frame of the reference particle. They include in the formalism that the particles are confined by the guiding and focusing magnetic fields, and that they are confined in a conducting vacuum pipe while interacting with each other via a Coulomb force. Numerical simulations has been performed to obtain the equilibrium structure. The effects of the shearing force, centrifugal force, and azimuthal variation of the focusing strength are investigated. It is found that a constant gradient storage ring can not give a crystalline beam, but that an alternating-gradient (AG) structure can. In such a machine the ground state is, except for one-dimensional (1-D) crystals, time-dependent. The ground state is a zero entropy state, despite the time-dependent, periodic variation of the focusing force. The nature of the ground state, similar to that found by Rahman and Schiffer, depends upon the density and the relative focusing strengths in the transverse directions. At low density, the crystal is 1-D. As the density increases, it transforms into various kinds of 2-D and 3-D crystals. If the energy of the beam is higher than the transition energy of the machine, the crystalline structure can not be formed for lack of radial focusing

Grounding line transient response in marine ice sheet models

Directory of Open Access Journals (Sweden)

A. S. Drouet

2013-03-01

Full Text Available Marine ice-sheet stability is mostly controlled by the dynamics of the grounding line, i.e. the junction between the grounded ice sheet and the floating ice shelf. Grounding line migration has been investigated within the framework of MISMIP (Marine Ice Sheet Model Intercomparison Project, which mainly aimed at investigating steady state solutions. Here we focus on transient behaviour, executing short-term simulations (200 yr of a steady ice sheet perturbed by the release of the buttressing restraint exerted by the ice shelf on the grounded ice upstream. The transient grounding line behaviour of four different flowline ice-sheet models has been compared. The models differ in the physics implemented (full Stokes and shallow shelf approximation, the numerical approach, as well as the grounding line treatment. Their overall response to the loss of buttressing is found to be broadly consistent in terms of grounding line position, rate of surface elevation change and surface velocity. However, still small differences appear for these latter variables, and they can lead to large discrepancies (> 100% observed in terms of ice sheet contribution to sea level when cumulated over time. Despite the recent important improvements of marine ice-sheet models in their ability to compute steady state configurations, our results question the capacity of these models to compute short-term reliable sea-level rise projections.

Classical many-particle systems with unique disordered ground states

Science.gov (United States)

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

2017-10-01

Classical ground states (global energy-minimizing configurations) of many-particle systems are typically unique crystalline structures, implying zero enumeration entropy of distinct patterns (aside from trivial symmetry operations). By contrast, the few previously known disordered classical ground states of many-particle systems are all high-entropy (highly degenerate) states. Here we show computationally that our recently proposed "perfect-glass" many-particle model [Sci. Rep. 6, 36963 (2016), 10.1038/srep36963] possesses disordered classical ground states with a zero entropy: a highly counterintuitive situation . For all of the system sizes, parameters, and space dimensions that we have numerically investigated, the disordered ground states are unique such that they can always be superposed onto each other or their mirror image. At low energies, the density of states obtained from simulations matches those calculated from the harmonic approximation near a single ground state, further confirming ground-state uniqueness. Our discovery provides singular examples in which entropy and disorder are at odds with one another. The zero-entropy ground states provide a unique perspective on the celebrated Kauzmann-entropy crisis in which the extrapolated entropy of a supercooled liquid drops below that of the crystal. We expect that our disordered unique patterns to be of value in fields beyond glass physics, including applications in cryptography as pseudorandom functions with tunable computational complexity.

Numerical analysis of propeller induced ground vortices by actuator disk model

NARCIS (Netherlands)

Yang, Y.; Veldhuis, L.L.M.; Eitelberg, G.

2017-01-01

Abstract: During the ground operation of aircraft, the interaction between the propulsor-induced flow field and the ground may lead to the generation of ground vortices. Utilizing numerical approaches, the source of vorticity entering ground vortices is investigated. The results show that the

Short-time variations of the ground water level

International Nuclear Information System (INIS)

Nilsson, Lars Y.

1977-09-01

Investigations have demonstrated that the ground water level of aquifers in the Swedish bedrock shows shorttime variations without changing their water content. The ground water level is among other things affected by regular tidal movements occuring in the ''solid'' crust of the earth variations in the atmospheric pressure strong earthquakes occuring in different parts of the world These effects proves that the system of fissures in the bedrock are not stable and that the ground water flow is influenced by both water- and airfilled fissures

Insights into Ground-Motion Processes from Intensity Data (Invited)

Science.gov (United States)

Atkinson, G. M.

2009-12-01

Analysis of intensity data gathered from the on-line “Did You Feel It?” (DYFI) questionnaire program (Wald et al., 1999, Seism. Res. L.) provides new insights into both contemporary and historical ground-motion processes; this is particularly important for sparsely-instrumented regions. The value of the DYFI data lies in their vast quantities and large spatial coverage. With thousands to tens of thousands of respondents providing information on the felt and damage characteristics of widely-felt earthquakes, DYFI intensity data provide surprisingly high resolution of ground-motion features. The large data quantities allow techniques such as binning to be used to bring out these features in a statistically-stable way (Atkinson and Wald, 2007, Seism. Res. L.), while correlations of the statistics of DYFI intensities with instrumental ground motions provide the link between intensity and engineering ground-motion parameters (Wald et al., 1999, Earthquake Spectra). This link is largely independent of region if its dependence on earthquake magnitude and distance is taken into account (Kaka and Atkinson, 2007, BSSA). Thus DYFI data provide a valuable tool with which ground motions can be estimated, if their felt and damage effects have been reported. This is useful both for understanding contemporary events in sparsely-instrumented regions, and for re-evaluating historical events, for which only intensity data are available. By using calibrated intensity observations, a number of ground-motion processes can be investigated based on DYFI and/or historical intensity data. For example, intensity data shed light on source scaling issues, and whether source parameters vary regionally. They can also be used to document regional attenuation features, such as the attenuation rate and its variation with distance (Atkinson and Wald, 2007). A key uncertainty in these investigations concerns the effect of spectral shape on intensity; the spectral shape is influenced by site

Neurons Forming Optic Glomeruli Compute Figure–Ground Discriminations in Drosophila

Science.gov (United States)

Aptekar, Jacob W.; Keleş, Mehmet F.; Lu, Patrick M.; Zolotova, Nadezhda M.

2015-01-01

Many animals rely on visual figure–ground discrimination to aid in navigation, and to draw attention to salient features like conspecifics or predators. Even figures that are similar in pattern and luminance to the visual surroundings can be distinguished by the optical disparity generated by their relative motion against the ground, and yet the neural mechanisms underlying these visual discriminations are not well understood. We show in flies that a diverse array of figure–ground stimuli containing a motion-defined edge elicit statistically similar behavioral responses to one another, and statistically distinct behavioral responses from ground motion alone. From studies in larger flies and other insect species, we hypothesized that the circuitry of the lobula—one of the four, primary neuropiles of the fly optic lobe—performs this visual discrimination. Using calcium imaging of input dendrites, we then show that information encoded in cells projecting from the lobula to discrete optic glomeruli in the central brain group these sets of figure–ground stimuli in a homologous manner to the behavior; “figure-like” stimuli are coded similar to one another and “ground-like” stimuli are encoded differently. One cell class responds to the leading edge of a figure and is suppressed by ground motion. Two other classes cluster any figure-like stimuli, including a figure moving opposite the ground, distinctly from ground alone. This evidence demonstrates that lobula outputs provide a diverse basis set encoding visual features necessary for figure detection. PMID:25972183

Ground-truth aerosol lidar observations: can the Klett solutions obtained from ground and space be equal for the same aerosol case?

International Nuclear Information System (INIS)

Ansmann, Albert

2006-01-01

Upcoming multiyear satellite lidar aerosol observations need strong support by a worldwide ground-truth lidar network. In this context the question arises as to whether the ground stations can deliver the same results as obtained from space when the Klett formalism is applied to elastic backscatter lidar data for the same aerosol case. This question is investigated based on simulations of observed cases of simple and complex aerosol layering. The results show that the differences between spaceborne and ground-based observations can be as large as20% for the backscatter and extinction coefficients and the optimum estimates of the column lidar ratios. In cases with complex aerosol layering, the application of the two-layer approach can lead to similar results (space, ground) and accurate products provided that horizontally homogeneous aerosol conditions are given

Study of grounding system of large tokamak device JT-60

International Nuclear Information System (INIS)

Arakawa, Kiyotsugu; Shimada, Ryuichi; Kishimoto, Hiroshi; Yabuno, Kohei; Ishigaki, Yukio.

1982-01-01

In the critical plasma testing facility JT-60 constructed by the Japan Atomic Energy Research Institute, high voltage, large current is required in an instant. Accordingly, for the protection of human bodies and the equipment, and for realizing the stable operation of the complex, precise control and measurement system, a large scale facility of grounding system is required. In case of the JT-60 experimental facility, the equipments with different functions in separate buildings are connected, therefore, it is an important point to avoid high potential difference between buildings. In the grounding system for the JT-60, a reticulate grounding electrode is laid for each building, and these electrodes are connected with a low impedance metallic duct called grounding trunk line. The power supply cables for various magnetic field coils, control lines and measurement lines are laid in the duct. It is a large problem to grasp quantitatively the effect of a grounding trunk line by analysis. The authors analyzed the phenomenon that large current flows into a grounding system by lightning strike or grounding. The fundamental construction of the grounding system for the JT-60, the condition for the analysis and the result of simulation are reported. (Kako, I.)

Young Children's Understanding of Cultural Common Ground

Science.gov (United States)

Liebal, Kristin; Carpenter, Malinda; Tomasello, Michael

2013-01-01

Human social interaction depends on individuals identifying the common ground they have with others, based both on personally shared experiences and on cultural common ground that all members of the group share. We introduced 3- and 5-year-old children to a culturally well-known object and a novel object. An experimenter then entered and asked,…

ECRB ALCOVE AND NICHE GROUND SUPPORT ANALYSIS

International Nuclear Information System (INIS)

J.W. Keifer

1999-01-01

The purpose of the analysis is to provide design bases for Enhanced Characterization of the Repository Block (ECRB) alcove and niche ground support drawings. The objective is to evaluate the ESF Alcove Ground Support Analysis (Ref 5.1) to determine if the calculations technically bound the ECRB alcoves and to address specific differences in the conditions and constraints

Longevity of Emplacement Drift Ground Support Materials

International Nuclear Information System (INIS)

D.H.Tang

2001-01-01

The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for the selection of materials for ground support that will function throughout the preclosure period of a potential repository at Yucca Mountain. REV 01 ICN 01 of this analysis is developed in accordance with AP-3.10Q, Analyses and Models, Revision 2, ICN 4, and prepared in accordance with the Technical Work Plan for Subsurface Design Section FY 01 Work Activities (CRWMS M and O 2001a). The objective of this analysis is to update the previous analysis (CRWMS M and O 2000a) to account for related changes in the Ground Control System Description Document (CRWMS M and O 2000b), the Monitored Geologic Repository Project Description Document, which is included in the Requirements and Criteria for Implementing a Repository Design that can be Operated Over a Range of Thermal Modes (BSC 2001), input information, and in environmental conditions, and to provide updated information on candidate ground support materials. Candidate materials for ground support are carbon steel and cement grout. Steel is mainly used for steel sets, lagging, channel, rock bolts, and wire mesh. Cement grout is only considered in the case of grouted rock bolts. Candidate materials for the emplacement drift invert are carbon steel and granular natural material. Materials are evaluated for the repository emplacement drift environment based on the updated thermal loading condition and waste package design. The analysis consists of the following tasks: (1) Identify factors affecting the longevity of ground support materials for use in emplacement drifts. (2) Review existing documents concerning the behavior of candidate ground support materials during the preclosure period. (3) Evaluate impacts of temperature and radiation effects on mechanical and thermal properties of steel. Assess corrosion potential of steel at emplacement drift environment. (4

ATHENS SEASONAL VARIATION OF GROUND RESISTANCE PREDICTION USING NEURAL NETWORKS

Directory of Open Access Journals (Sweden)

S. Anbazhagan

2015-10-01

Full Text Available The objective in ground resistance is to attain the most minimal ground safety esteem conceivable that bodes well monetarily and physically. An application of artificial neural networks (ANN to presage and relegation has been growing rapidly due to sundry unique characteristics of ANN models. A decent forecast is able to capture the dubiousness associated with those ground resistance. A portion of the key instabilities are soil composition, moisture content, temperature, ground electrodes and spacing of the electrodes. Propelled by this need, this paper endeavors to develop a generalized regression neural network (GRNN to predict the ground resistance. The GRNN has a single design parameter and expeditious learning and efficacious modeling for nonlinear time series. The precision of the forecast is applied to the Athens seasonal variation of ground resistance that shows the efficacy of the proposed approach.

Ground-water hydraulics - A summary of lectures presented by John G. Ferris at short courses conducted by the Ground Water Branch, part 1, Theory

Science.gov (United States)

Knowles, D.B.

1955-01-01

The objective of the Ground Water Branch is to evaluate the occurrence, availability, and quality of ground water.  The science of ground-water hydrology is applied toward attaining that goal.  Although many ground-water investigations are of a qualitative nature, quantitative studies are necessarily an integral component of the complete evaluation of occurrence and availability.  The worth of an aquifer as a fully developed source of water depends largely on two inherent characteristics: its ability to store, and its ability to transmit water.  Furthermore, quantitative knowledge of these characteristics facilitates measurement of hydrologic entities such as recharge, leakage, evapotranspiration, etc.  It is recognized that these two characteristics, referred to as the coefficients of storage and transmissibility, generally provide the very foundation on which quantitative studies are constructed.  Within the science of ground-water hydrology, ground-water hydraulics methods are applied to determine these constats from field data.

From a pluralism of grounds to proto-legal relations: accounting for the grounds of obligations of justice

OpenAIRE

Pavlakos, Georgios

2017-01-01

In this paper I discuss critically Mathias Risse's paper “Responsibility and Global Justice.” First, I argue that for Risse's pluralist account of the grounds of justice to hold together, there is need to presuppose a monist standpoint which ultimately contributes to grounding principles of justice. Second, I point out that Risse's understanding of obligations of accountability and justification is rather narrow in that it functions as an addendum to obligations of justice. Conversely, I will...

Design basis ground motion (Ss) required on new regulatory guide

International Nuclear Information System (INIS)

Kamae, Katsuhiro

2013-01-01

New regulatory guide is enforced on July 8. Here, it is introduced how the design basis ground motion (Ss) for seismic design of nuclear power reactor facilities was revised on the new guide. Ss is formulated as two types of earthquake ground motions, earthquake ground motions with site specific earthquake source and with no such specific source locations. The latter is going to be revised based on the recent observed near source ground motions. (author)

Sampling art for ground-water monitoring wells in nuclide migration

International Nuclear Information System (INIS)

Liu Wenyuan; Tu Guorong; Dang Haijun; Wang Xuhui; Ke Changfeng

2010-01-01

Ground-Water sampling is one of the key parts in field nuclide migration. The objective of ground-water sampling program is to obtain samples that are representative of formation-quality water. In this paper, the ground-water sampling standards and the developments of sampling devices are reviewed. We also designed the sampling study projects which include the sampling methods, sampling parameters and the elementary devise of two types of ground-Water sampling devices. (authors)

Speciation and transport of radionuclides in ground water

International Nuclear Information System (INIS)

Robertson, D.E.; Toste, A.P.; Abel, K.H.; Cowan, C.E.; Jenne, E.A.; Thomas, C.W.

1984-01-01

Studies of the chemical speciation of a number of radionuclides migrating in a slightly contaminated ground water plume are identifying the most mobile species and providing an opportunity to test and/or validate geochemical models of radionuclide transport in ground waters. Results to date have shown that most of the migrating radionuclides are present in anionic or nonionic forms. These include anionic forms of 55 Fe, 60 Co, /sup 99m/Tc, 106 Ru, 131 I, and nonionic forms of 63 Ni and 125 Sb. Strontium-70 and a small fraction of the mobile 60 Co are the only cationic radionuclides which have been detected moving in the ground water plume beyond 30 meters from the source. A comparison of the observed chemical forms with the predicted species calculated from modeling thermodynamic data and ground water chemical parameters has indicated a good agreement for most of the radioelements in the system, including Tc, Np, Cs, Sr, Ce, Ru, Sb, Zn, and Mn. The discrepancies between observed and calculated solutions species were noted for Fe, Co, Ni and I. Traces of Fe, Co, and Ni were observed to migrate in anionic or nonionic forms which the calculations failed to predict. These anionic/nonionic species may be organic complexes having enhanced mobility in ground waters. The radioiodine, for example, was shown to behave totally as an anion but further investigation revealed that 49-57% of this anionic iodine was organically bound. The ground water and aqueous extracts of trench sediments contain a wide variety of organic compounds, some of which could serve as complexing agents for the radionuclides. These results indicate the need for further research at a variety of field sites in defining precisely the chemical forms of the mobile radionuclide species, and in better understanding the role of dissolved organic materials in ground water transport of radionuclides

Basin scale management of surface and ground water

International Nuclear Information System (INIS)

Tracy, J.C.; Al-Sharif, M.

1993-01-01

An important element in the economic development of many regions of the Great Plains is the availability of a reliable water supply. Due to the highly variable nature of the climate through out much of the Great Plains region, non-controlled stream flow rates tend to be highly variable from year to year. Thus, the primary water supply has tended towards developing ground water aquifers. However, in regions where shallow ground water is extracted for use, there exists the potential for over drafting aquifers to the point of depleting hydraulically connected stream flows, which could adversely affect the water supply of downstream users. To prevent the potential conflict that can arise when a basin's water supply is being developed or to control the water extractions within a developed basin requires the ability to predict the effect that water extractions in one region will have on water extractions from either surface or ground water supplies else where in the basin. This requires the ability to simulate ground water levels and stream flows on a basin scale as affected by changes in water use, land use practices and climatic changes within the basin. The outline for such a basin scale surface water-ground water model has been presented in Tracy (1991) and Tracy and Koelliker (1992), and the outline for the mathematical programming statement to aid in determining the optimal allocation of water on a basin scale has been presented in Tracy and Al-Sharif (1992). This previous work has been combined into a computer based model with graphical output referred to as the LINOSA model and was developed as a decision support system for basin managers. This paper will present the application of the LINOSA surface-ground water management model to the Rattlesnake watershed basin that resides within Ground Water Management District Number 5 in south central Kansas

Evaluation of Ground Water Near Sidney, Western Nebraska, 2004-05

Science.gov (United States)

Steele, G.V.; Sibray, S.S.; Quandt, K.A.

2007-01-01

During times of drought, ground water in the Lodgepole Creek area around Sidney, western Nebraska, may be insufficient to yield adequate supplies to private and municipal wells. Alternate sources of water exist in the Cheyenne Tablelands north of the city, but these sources are limited in extent. In 2003, the U.S. Geological Survey and the South Platte Natural Resources District began a cooperative study to evaluate the ground water near Sidney. The 122-square-mile study area lies in the south-central part of Cheyenne County, with Lodgepole Creek and Sidney Draw occupying the southern and western parts of the study area and the Cheyenne Tablelands occupying most of the northern part of the study area. Twenty-nine monitoring wells were installed and then sampled in 2004 and 2005 for physical characteristics, nutrients, major ions, and stable isotopes. Some of the 29 sites also were sampled for ground-water age dating. Ground water is limited in extent in the tableland areas. Spring 2005 depths to ground water in the tableland areas ranged from 95 to 188 feet. Ground-water flow in the tableland areas primarily is northeasterly. South of a ground-water divide, ground-water flows southeasterly toward Lodgepole Creek Valley. Water samples from monitoring wells in the Ogallala Group were predominantly a calcium bicarbonate type, and those from monitoring wells in the Brule Formation were a sodium bicarbonate type. Water samples from monitoring wells open to the Brule sand were primarily a calcium bicarbonate type at shallow depths and a sodium bicarbonate type at deeper depths. Ground water in Lodgepole Creek Valley had a strong sodium signature, which likely results from most of the wells being open to the Brule. Concentrations of sodium and nitrate in ground-water samples from the Ogallala were significantly different than in water samples from the Brule and Brule sand. In addition, significant differences were seen in concentrations of calcium between water samples

Ground-water conditions in Utah, spring of 1994

Science.gov (United States)

Allen, D.V.; Garrett, R.B.; Sory, J.D.; Burden, Carole B.; Danner, M.R.; Herbert, L.R.; Steiger, J.I.; ReMillard, M.D.; Slaugh, B.A.; Swenson, R.L.; Howells, J.H.; Christiansen, H.K.; Bagley, A.D.

1994-01-01

This is the thirty-first in a series of annual reports that describe ground-water conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Division of Water Resources, provide data to enable interested parties to keep abreast of changing ground-water conditions.This report, like the others in the series, contains information on well construction, ground-water withdrawal from wells, water-level changes, related changes in precipitation and streamflow, and chemical quality of water. Supplementary data, such as maps showing water-level contours, are included in reports of this series only for those years or areas for which applicable data are available and are important to a discussion of changing ground-water conditions.This report includes individual discussions of selected significant areas of ground-water development in the State for calendar year 1993. Water-level fluctuations and selected related data, however, are described from the spring of 1989 to the spring of 1994. Much of the data used in this report were collected by the U.S. Geological Survey in cooperation with the Divisions of Water Rights and Water Resources, Utah Department of Natural Resources.

Identification of technical guidance related to ground water monitoring

Energy Technology Data Exchange (ETDEWEB)

Vogelsberger, R.R.; Smith, E.D.; Broz, M.; Wright, J.C. Jr.

1987-05-01

Monitoring of ground water quality is a key element of ground water protection and is mandated by several federal and state laws concerned with water quality or waste management. Numerous regulatory guidance documents and technical reports discuss various aspects of ground water monitoring, but at present there is no single source of guidance on procedures and practices for ground water monitoring. This report is intended to assist US Department of Energy (DOE) officials and facility operating personnel in identifying sources of guidance for developing and implementing ground water monitoring programs that are technically sound and that comply with applicable regulations. Federal statutes and associated regulations were reviewed to identify requirements related to ground water monitoring, and over 160 documents on topics related to ground water monitoring were evaluated for their technical merit, their utility as guidance for regulatory compliance, and their relevance to DOE's needs. For each of 15 technical topics involved in ground water monitoring, the report presents (1) a review of federal regulatory requirements and representative state requirements, (2) brief descriptions of the contents and merits of available guidance documents and technical references, and (3) recommendations of the guidance documents or other technical resources that appear to be most appropriate for use in DOE's monitoring activities. The contents of the report are applicable to monitoring activities involving both radioactive and nonradioactive substances. The main sources of regulatory requirements considered in the report are the Atomic Energy Act (including the Uranium Mill Tailings Radiation Control Act), Resource Conservation and Recovery Act, Comprehensive Environmental Response, Compensation and Liability Act, Safe Drinking Water Act, Toxic Substances Control Act, and Federal Water Pollution Control Act.

Identification of technical guidance related to ground water monitoring

International Nuclear Information System (INIS)

Vogelsberger, R.R.; Smith, E.D.; Broz, M.; Wright, J.C. Jr.

1987-05-01

Monitoring of ground water quality is a key element of ground water protection and is mandated by several federal and state laws concerned with water quality or waste management. Numerous regulatory guidance documents and technical reports discuss various aspects of ground water monitoring, but at present there is no single source of guidance on procedures and practices for ground water monitoring. This report is intended to assist US Department of Energy (DOE) officials and facility operating personnel in identifying sources of guidance for developing and implementing ground water monitoring programs that are technically sound and that comply with applicable regulations. Federal statutes and associated regulations were reviewed to identify requirements related to ground water monitoring, and over 160 documents on topics related to ground water monitoring were evaluated for their technical merit, their utility as guidance for regulatory compliance, and their relevance to DOE's needs. For each of 15 technical topics involved in ground water monitoring, the report presents (1) a review of federal regulatory requirements and representative state requirements, (2) brief descriptions of the contents and merits of available guidance documents and technical references, and (3) recommendations of the guidance documents or other technical resources that appear to be most appropriate for use in DOE's monitoring activities. The contents of the report are applicable to monitoring activities involving both radioactive and nonradioactive substances. The main sources of regulatory requirements considered in the report are the Atomic Energy Act (including the Uranium Mill Tailings Radiation Control Act), Resource Conservation and Recovery Act, Comprehensive Environmental Response, Compensation and Liability Act, Safe Drinking Water Act, Toxic Substances Control Act, and Federal Water Pollution Control Act

Creating Space Plasma from the Ground

Science.gov (United States)

2016-05-12

AFRL-AFOSR-VA-TR-2016-0179 CREATING SPACE PLASMA FROM THE GROUND Herbert C Carlson UTAH STATE UNIVERSITY Final Report 05/12/2016 DISTRIBUTION A...DATE (DD-MM-YYYY) 05/14/2016 2. REPORT TYPE Final 3. DATES COVERED (From - To) 08/14/2012-05/14/2016 4. TITLE AND SUBTITLE Creating space plasma from...Report (2016) Creating Space Plasma from the Ground Grant FA9550-11-1-0236 AFOSR Program Manager Dr. Kent Miller PI: Herbert C. Carlson Center for

Running the figure to the ground: figure-ground segmentation during visual search.

Science.gov (United States)

Ralph, Brandon C W; Seli, Paul; Cheng, Vivian O Y; Solman, Grayden J F; Smilek, Daniel

2014-04-01

We examined how figure-ground segmentation occurs across multiple regions of a visual array during a visual search task. Stimuli consisted of arrays of black-and-white figure-ground images in which roughly half of each image depicted a meaningful object, whereas the other half constituted a less meaningful shape. The colours of the meaningful regions of the targets and distractors were either the same (congruent) or different (incongruent). We found that incongruent targets took longer to locate than congruent targets (Experiments 1, 2, and 3) and that this segmentation-congruency effect decreased when the number of search items was reduced (Experiment 2). Furthermore, an analysis of eye movements revealed that participants spent more time scrutinising the target before confirming its identity on incongruent trials than on congruent trials (Experiment 3). These findings suggest that the distractor context influences target segmentation and detection during visual search. Copyright © 2014 Elsevier B.V. All rights reserved.

Thunderstorm ground enhancements (TGEs) abruptly terminated by negative cloud-to-ground lightnings

International Nuclear Information System (INIS)

Chilingarian, A.; Hovsepyan, G.; Khanikyanc, G.; Pokhsraryan, D.; Soghomonyan, S.

2016-01-01

The relationship of lightnings and particle fluxes in the thunderclouds is not fully understood to date. Using the particle beams (the so-called Thunderstorm Ground Enhancements – TGEs) generated in the lower part of clouds by the strong electric fields as a probe, we investigate the characteristics of the related atmospheric discharges. The well-known effect of the TGE dynamics is the abrupt termination of the particle flux. We demonstrate that among 12 atmospheric discharges that abruptly terminated TGE all are the negative cloud-to-ground lightnings. The flux termination and lightning occurred at one and the same second. With new precise electronics on millisecond time scales we can see that particle flux decline occurred simultaneously with abrupt increase of electrostatic field after the return stroke of the lightning. Therefore, the declining of particle flux is connected with rearranging of charge centers in the cloud involving removal of the Lower Positive Charged Region (LPCR). (author)

Tunnel flexibility effect on the ground surface acceleration response

Science.gov (United States)

Baziar, Mohammad Hassan; Moghadam, Masoud Rabeti; Choo, Yun Wook; Kim, Dong-Soo

2016-09-01

Flexibility of underground structures relative to the surrounding medium, referred to as the flexibility ratio, is an important factor that influences their dynamic interaction. This study investigates the flexibility effect of a box-shaped subway tunnel, resting directly on bedrock, on the ground surface acceleration response using a numerical model verified against dynamic centrifuge test results. A comparison of the ground surface acceleration response for tunnel models with different flexibility ratios revealed that the tunnels with different flexibility ratios influence the acceleration response at the ground surface in different ways. Tunnels with lower flexibility ratios have higher acceleration responses at short periods, whereas tunnels with higher flexibility ratios have higher acceleration responses at longer periods. The effect of the flexibility ratio on ground surface acceleration is more prominent in the high range of frequencies. Furthermore, as the flexibility ratio of the tunnel system increases, the acceleration response moves away from the free field response and shifts towards the longer periods. Therefore, the flexibility ratio of the underground tunnels influences the peak ground acceleration (PGA) at the ground surface, and may need to be considered in the seismic zonation of urban areas.

Development of a Ground Water Data Portal for Interoperable Data Exchange within the U.S. National Ground Water Monitoring Network and Beyond

Science.gov (United States)

Booth, N. L.; Brodaric, B.; Lucido, J. M.; Kuo, I.; Boisvert, E.; Cunningham, W. L.

2011-12-01

The need for a national groundwater monitoring network within the United States is profound and has been recognized by organizations outside government as a major data gap for managing ground-water resources. Our country's communities, industries, agriculture, energy production and critical ecosystems rely on water being available in adequate quantity and suitable quality. To meet this need the Subcommittee on Ground Water, established by the Federal Advisory Committee on Water Information, created a National Ground Water Monitoring Network (NGWMN) envisioned as a voluntary, integrated system of data collection, management and reporting that will provide the data needed to address present and future ground-water management questions raised by Congress, Federal, State and Tribal agencies and the public. The NGWMN Data Portal is the means by which policy makers, academics and the public will be able to access ground water data through one seamless web-based application from disparate data sources. Data systems in the United States exist at many organizational and geographic levels and differing vocabulary and data structures have prevented data sharing and reuse. The data portal will facilitate the retrieval of and access to groundwater data on an as-needed basis from multiple, dispersed data repositories allowing the data to continue to be housed and managed by the data provider while being accessible for the purposes of the national monitoring network. This work leverages Open Geospatial Consortium (OGC) data exchange standards and information models. To advance these standards for supporting the exchange of ground water information, an OGC Interoperability Experiment was organized among international participants from government, academia and the private sector. The experiment focused on ground water data exchange across the U.S. / Canadian border. WaterML2.0, an evolving international standard for water observations, encodes ground water levels and is exchanged

A novel design method for ground source heat pump

Directory of Open Access Journals (Sweden)

Dong Xing-Jie

2014-01-01

Full Text Available This paper proposes a novel design method for ground source heat pump. The ground source heat pump operation is controllable by using several parameters, such as the total meters of buried pipe, the space between wells, the thermal properties of soil, thermal resistance of the well, the initial temperature of soil, and annual dynamic load. By studying the effect of well number and well space, we conclude that with the increase of the well number, the inlet and outlet water temperatures decrease in summer and increase in winter, which enhance the efficiency of ground source heat pump. The well space slightly affects the water temperatures, but it affects the soil temperature to some extent. Also the ground source heat pump operations matching with cooling tower are investigated to achieve the thermal balance. This method greatly facilitates ground source heat pump design.

The ATLAS SCT grounding and shielding concept and implementation

CERN Document Server

Bates, RL; Bernabeu, J; Bizzell, J; Bohm, J; Brenner, R; Bruckman de Renstrom, P A; Catinaccio, A; Cindro, V; Ciocio, A; Civera, J V; Chouridou, S; Dervan, P; Dick, B; Dolezal, Z; Eklund, L; Feld, L; Ferrere, D; Gadomski, S; Gonzalez, F; Gornicki, E; Greenhall, A; Grillo, A A; Grosse-Knetter, J; Gruwe, M; Haywood, S; Hessey, N P; Ikegami, Y; Jones, T J; Kaplon, J; Kodys, P; Kohriki, T; Kondo, T; Koperny, S; Lacasta, C; Lozano Bahilo, J; Malecki, P; Martinez-McKinney, F; McMahon, S J; McPherson, A; Mikulec, B; Mikus, M; Moorhead, G F; Morrissey, M C; Nagai, K; Nichols, A; O'Shea, V; Pater, J R; Peeters, S J M; Pernegger, H; Perrin, E; Phillips, P W; Pieron, J P; Roe, S; Sanchez, J; Spencer, E; Stastny, J; Tarrant, J; Terada, S; Tyndel, M; Unno, Y; Wallny, R; Weber, M; Weidberg, A R; Wells, P S; Werneke, P; Wilmut, I

2012-01-01

This paper describes the design and implementation of the grounding and shielding system for the ATLAS SemiConductor Tracker (SCT). The mitigation of electromagnetic interference and noise pickup through power lines is the critical design goal as they have the potential to jeopardize the electrical performance. We accomplish this by adhering to the ATLAS grounding rules, by avoiding ground loops and isolating the different subdetectors. Noise sources are identified and design rules to protect the SCT against them are described. A rigorous implementation of the design was crucial to achieve the required performance. This paper highlights the location, connection and assembly of the different components that affect the grounding and shielding system: cables, filters, cooling pipes, shielding enclosure, power supplies and others. Special care is taken with the electrical properties of materials and joints. The monitoring of the grounding system during the installation period is also discussed. Finally, after con...

Grounding Lines Detecting Using LANDSAT8 Oli and CRYOSAT-2 Data Fusion

Science.gov (United States)

Li, F.; Guo, Y.; Zhang, Y.; Zhang, S.

2018-04-01

The grounding zone is the region where ice transitions from grounded ice sheet to freely floating ice shelf, grounding lines are actually more of a zone, typically over several kilometers. The mass loss from Antarctica is strongly linked to changes in the ice shelves and their grounding lines, since the variation in the grounding line can result in very rapid changes in glacier and ice-shelf behavior. Based on remote sensing observations, five global Antarctic grounding line products have been released internationally, including MOA, ASAID, ICESat, MEaSUREs, and Synthesized grounding lines. However, the five products could not provide the annual grounding line products of the whole Antarctic, even some products have stopped updating, which limits the time series analysis of Antarctic material balance to a certain extent. Besides, the accurate of single remote-sensing data based grounding line products is far from satisficed. Therefore, we use algorithms to extract grounding lines with SAR and Cryosat-2 data respectively, and combine the results of two kinds of grounding lines to obtain new products, we obtain a mature grounding line extraction algorithm process, so that we can realize the extraction of grounding line of the Antarctic each year in the future. The comparison between fusion results and the MOA product results indicate that there is a maximum deviation of 188.67 meters between the MOA product and the fusion result.

Structural Design and Response in Collision and Grounding

DEFF Research Database (Denmark)

Brown, Alan; Tikka, Kirsi; Daidola, John C.

2000-01-01

on Collision and Grounding of Ships, to be held in Copenhagen, July 1-3,2001, will also present and discuss many of the results of this panel and other related research. The paper discusses four primary areas of panel work: collision and grounding models, data, accident scenarios and design applications....... A probabilistic framework for assessing the crashworthiness of ships is presented. Results obtained from various grounding and collision models are compared to validating cases and to each other. Data necessary for proper model validation and probabilistic accident scenario development are identified. Deformable...

Calculation of Grounding Grids Parameter at Arbitrary Geometry

Directory of Open Access Journals (Sweden)

Carlos L. B. Silva

2017-06-01

Full Text Available This paper deals with the computation of ground resistance, surface voltage, touch voltage and step voltage, to mesh with horizontal wires arranged in different angles. The computer program implemented used in the mathematical modeling is based on the method proposed by Heppe, which allows obtaining the grounding parameters for homogeneous soil and soil stratified in two layers. The results obtained with the proposed method will be compared with other methods in literature. Also will be presented the results of a grounding grid using wires at various angles.

LANDSAT-D ground segment operations plan, revision A

Science.gov (United States)

Evans, B.

1982-01-01

The basic concept for the utilization of LANDSAT ground processing resources is described. Only the steady state activities that support normal ground processing are addressed. This ground segment operations plan covers all processing of the multispectral scanner and the processing of thematic mapper through data acquisition and payload correction data generation for the LANDSAT 4 mission. The capabilities embedded in the hardware and software elements are presented from an operations viewpoint. The personnel assignments associated with each functional process and the mechanisms available for controlling the overall data flow are identified.

Deficit in figure-ground segmentation following closed head injury.

Science.gov (United States)

Baylis, G C; Baylis, L L

1997-08-01

Patient CB showed a severe impairment in figure-ground segmentation following a closed head injury. Unlike normal subjects, CB was unable to parse smaller and brighter parts of stimuli as figure. Moreover, she did not show the normal effect that symmetrical regions are seen as figure, although she was able to make overt judgments of symmetry. Since she was able to attend normally to isolated objects, CB demonstrates a dissociation between figure ground segmentation and subsequent processes of attention. Despite her severe impairment in figure-ground segmentation, CB showed normal 'parallel' single feature visual search. This suggests that figure-ground segmentation is dissociable from 'preattentive' processes such as visual search.

A Decentralized Interactive Architecture for Aerial and Ground Mobile Robots Cooperation

OpenAIRE

Harik, El Houssein Chouaib; Guérin, François; Guinand, Frédéric; Brethé, Jean-François; Pelvillain, Hervé

2014-01-01

International audience; —This paper presents a novel decentralized interactive architecture for aerial and ground mobile robots cooperation. The aerial mobile robot is used to provide a global coverage during an area inspection, while the ground mobile robot is used to provide a local coverage of ground features. We include a human-in-the-loop to provide waypoints for the ground mobile robot to progress safely in the inspected area. The aerial mobile robot follows continuously the ground mobi...

Shallow ground disposal of radioactive wastes

International Nuclear Information System (INIS)

1981-01-01

This guidebook outlines the factors to be considered in site selection, design, operation, shut-down and surveillance as well as the regulatory requirements of repositories for safe disposal of radioactive waste in shallow ground. No attempt is made to summarize the existing voluminous literature on the many facets of radioactive waste disposal. In the context of this guidebook, shallow ground disposal refers to the emplacement of radioactive waste, with or without engineered barriers, above or below the ground surface, where the final protective covering is of the order of a few metres thick. Deep geological disposal and other underground disposal methods, management of mill tailings and disposal into the sea have been or will be considered in other IAEA publications. These guidelines have been made sufficiently general to cover a broad variety of climatic, hydrogeological and biological conditions. They may need to be interpreted or modified to reflect local conditions and national regulations

Ground state searches in fcc intermetallics

International Nuclear Information System (INIS)

Wolverton, C.; de Fontaine, D.; Ceder, G.; Dreysse, H.

1991-12-01

A cluster expansion is used to predict the fcc ground states, i.e., the stable phases at zero Kelvin as a function of composition, for alloy systems. The intermetallic structures are not assumed, but derived regorously by minimizing the configurational energy subject to linear constraints. This ground state search includes pair and multiplet interactions which spatially extend to fourth nearest neighbor. A large number of these concentration-independent interactions are computed by the method of direct configurational averaging using a linearized-muffin-tin orbital Hamiltonian cast into tight binding form (TB-LMTO). The interactions, derived without the use of any adjustable or experimentally obtained parameters, are compared to those calculated via the generalized perturbation method extention of the coherent potential approximation within the context of a KKR Hamiltonian (KKR-CPA-GPM). Agreement with the KKR-CPA-GPM results is quite excellent, as is the comparison of the ground state results with the fcc-based portions of the experimentally-determined phase diagrams under consideration

Examining the Nexus between Grounded Theory and Symbolic Interactionism

OpenAIRE

P. Jane Milliken RN, PhD; Rita Schreiber RN, DNS

2012-01-01

Grounded theory is inherently symbolic interactionist; however, not all grounded theory researchers appreciate its importance or benefit from its influence. Elsewhere, we have written about the intrinsic relationship between grounded theory and symbolic interactionism, highlighting the silent, fundamental contribution of symbolic interactionism to the methodology. At the same time, there are significant insights to be had by bringing a conscious awareness of the philosophy of symbolic interac...

Ground motions and its effects in accelerator design

International Nuclear Information System (INIS)

Fischer, G.E.

1984-07-01

This lecture includes a discussion of types of motion, frequencies of interest, measurements at SLAC, some general comments regarding local sources of ground motion at SLAC, and steps that can be taken to minimize the effects of ground motion on accelerators

Earthquake Ground Motion Measures for Seismic Response Evaluation of Structures

Energy Technology Data Exchange (ETDEWEB)

Cho, In-Kil; Ahn, Seong-Moon; Choun, Young-Sun; Seo, Jeong-Moon

2007-03-15

This study used the assessment results of failure criteria - base shear, story drift, top acceleration and top displacement - for a PSC containment building subjected to 30 sets of near-fault ground motions to evaluate the earthquake ground motion intensity measures. Seven intensity measures, peak ground acceleration(PGA), peak ground velocity(PGV), spectral acceleration(Sa), velocity(Sv), spectrum intensity for acceleration(SIa), velocity(SIv) and displacement(SId), were used to represent alternative ground motion. The regression analyses of the failure criteria for a PSC containment building were carried out to evaluate a proper intensity measure by using two regression models and seven ground motion parameters. The regression analysis results demonstrate the correlation coefficients of the failure criteria in terms of the candidate IM. From the results, spectral acceleration(Sa) is estimated as the best parameter for a evaluation of the structural safety for a seismic PSA.

Scaling earthquake ground motions for performance-based assessment of buildings

Science.gov (United States)

Huang, Y.-N.; Whittaker, A.S.; Luco, N.; Hamburger, R.O.

2011-01-01

The impact of alternate ground-motion scaling procedures on the distribution of displacement responses in simplified structural systems is investigated. Recommendations are provided for selecting and scaling ground motions for performance-based assessment of buildings. Four scaling methods are studied, namely, (1)geometric-mean scaling of pairs of ground motions, (2)spectrum matching of ground motions, (3)first-mode-period scaling to a target spectral acceleration, and (4)scaling of ground motions per the distribution of spectral demands. Data were developed by nonlinear response-history analysis of a large family of nonlinear single degree-of-freedom (SDOF) oscillators that could represent fixed-base and base-isolated structures. The advantages and disadvantages of each scaling method are discussed. The relationship between spectral shape and a ground-motion randomness parameter, is presented. A scaling procedure that explicitly considers spectral shape is proposed. ?? 2011 American Society of Civil Engineers.

Neurons forming optic glomeruli compute figure-ground discriminations in Drosophila.

Science.gov (United States)

Aptekar, Jacob W; Keleş, Mehmet F; Lu, Patrick M; Zolotova, Nadezhda M; Frye, Mark A

2015-05-13

Many animals rely on visual figure-ground discrimination to aid in navigation, and to draw attention to salient features like conspecifics or predators. Even figures that are similar in pattern and luminance to the visual surroundings can be distinguished by the optical disparity generated by their relative motion against the ground, and yet the neural mechanisms underlying these visual discriminations are not well understood. We show in flies that a diverse array of figure-ground stimuli containing a motion-defined edge elicit statistically similar behavioral responses to one another, and statistically distinct behavioral responses from ground motion alone. From studies in larger flies and other insect species, we hypothesized that the circuitry of the lobula--one of the four, primary neuropiles of the fly optic lobe--performs this visual discrimination. Using calcium imaging of input dendrites, we then show that information encoded in cells projecting from the lobula to discrete optic glomeruli in the central brain group these sets of figure-ground stimuli in a homologous manner to the behavior; "figure-like" stimuli are coded similar to one another and "ground-like" stimuli are encoded differently. One cell class responds to the leading edge of a figure and is suppressed by ground motion. Two other classes cluster any figure-like stimuli, including a figure moving opposite the ground, distinctly from ground alone. This evidence demonstrates that lobula outputs provide a diverse basis set encoding visual features necessary for figure detection. Copyright © 2015 the authors 0270-6474/15/357587-13$15.00/0.

Nitrogen mediates above-ground effects of ozone but not below-ground effects in a rhizomatous sedge

International Nuclear Information System (INIS)

Jones, M.L.M.; Hodges, G.; Mills, G.

2010-01-01

Ozone and atmospheric nitrogen are co-occurring pollutants with adverse effects on natural grassland vegetation. Plants of the rhizomatous sedge Carex arenaria were exposed to four ozone regimes representing increasing background concentrations (background-peak): 10-30, 35-55, 60-80 and 85-105 ppb ozone at two nitrogen levels: 12 and 100 kg N ha -1 yr -1 . Ozone increased the number and proportion of senesced leaves, but not overall leaf number. There was a clear nitrogen x ozone interaction with high nitrogen reducing proportional senescence in each treatment and increasing the ozone dose (AOT40) at which enhanced senescence occurred. Ozone reduced total biomass due to significant effects on root biomass. There were no interactive effects on shoot:root ratio. Rhizome tissue N content was increased by both nitrogen and ozone. Results suggest that nitrogen mediates above-ground impacts of ozone but not impacts on below-ground resource translocation. This may lead to complex interactive effects between the two pollutants on natural vegetation. - Nitrogen alters threshold of ozone-induced senescence, but not below-ground resource allocation.

Stochastic correlative firing for figure-ground segregation.

Science.gov (United States)

Chen, Zhe

2005-03-01

Segregation of sensory inputs into separate objects is a central aspect of perception and arises in all sensory modalities. The figure-ground segregation problem requires identifying an object of interest in a complex scene, in many cases given binaural auditory or binocular visual observations. The computations required for visual and auditory figure-ground segregation share many common features and can be cast within a unified framework. Sensory perception can be viewed as a problem of optimizing information transmission. Here we suggest a stochastic correlative firing mechanism and an associative learning rule for figure-ground segregation in several classic sensory perception tasks, including the cocktail party problem in binaural hearing, binocular fusion of stereo images, and Gestalt grouping in motion perception.

Strong ground motion prediction using virtual earthquakes.

Science.gov (United States)

Denolle, M A; Dunham, E M; Prieto, G A; Beroza, G C

2014-01-24

Sedimentary basins increase the damaging effects of earthquakes by trapping and amplifying seismic waves. Simulations of seismic wave propagation in sedimentary basins capture this effect; however, there exists no method to validate these results for earthquakes that have not yet occurred. We present a new approach for ground motion prediction that uses the ambient seismic field. We apply our method to a suite of magnitude 7 scenario earthquakes on the southern San Andreas fault and compare our ground motion predictions with simulations. Both methods find strong amplification and coupling of source and structure effects, but they predict substantially different shaking patterns across the Los Angeles Basin. The virtual earthquake approach provides a new approach for predicting long-period strong ground motion.

National water summary 1986; Hydrologic events and ground-water quality

Science.gov (United States)

Moody, David W.; Carr, Jerry E.; Chase, Edith B.; Paulson, Richard W.

1988-01-01

Ground water is one of the most important natural resources of the United States and degradation of its quality could have a major effect on the welfare of the Nation. Currently (1985), ground water is the source of drinking water for 53 percent of the Nation's population and for more than 97 percent of its rural population. It is the source of about 40 percent of the Nation's public water supply, 33 percent of water for irrigation, and 17 percent of freshwater for selfsupplied industries.Ground water also is the source of about 40 percent of the average annual streamflow in the United States, although during long periods of little or no precipitation, ground-water discharges provide nearly all of the base streamflow. This hydraulic connection between aquifers and streams implies that if a persistent pollutant gets into an aquifer, it eventually could discharge into a stream.Information presented in the 1986 National Water Summary clearly shows that the United States has very large amounts of potable ground water available for use. Although naturally occurring constituents, such as nitrate, and human-induced substances, such as synthetic organic chemicals, frequently are detected in ground water, their concentrations usually do not exceed existing Federal or State standards or guidelines for maximum concentrations in drinking water.Troublesome contamination of ground water falls into two basic categories related to the source or sources of the contamination. Locally, high concentrations of a variety of toxic metals, organic chemicals, and petroleum products have been detected in ground water associated with point sources such as wastedisposal sites, storage-tank leaks, and hazardous chemical spills. These types of local problems commonly occur in densely populated urban areas and industrialized areas. Larger, multicounty areas also have been identified where contamination frequently is found in shallow wells. These areas generally are associated with broad

Uranium isotopes in ground water as a prospecting technique

International Nuclear Information System (INIS)

Cowart, J.B.; Osmond, J.K.

1980-02-01

The isotopic concentrations of dissolved uranium were determined for 300 ground water samples near eight known uranium accumulations to see if new approaches to prospecting could be developed. It is concluded that a plot of 234 U/ 238 U activity ratio (A.R.) versus uranium concentration (C) can be used to identify redox fronts, to locate uranium accumulations, and to determine whether such accumulations are being augmented or depleted by contemporary aquifer/ground water conditions. In aquifers exhibiting flow-through hydrologic systems, up-dip ground water samples are characterized by high uranium concentration values (> 1 to 4 ppB) and down-dip samples by low uranium concentration values (less than 1 ppB). The boundary between these two regimes can usually be identified as a redox front on the basis of regional water chemistry and known uranium accumulations. Close proximity to uranium accumulations is usually indicated either by very high uranium concentrations in the ground water or by a combination of high concentration and high activity ratio values. Ground waters down-dip from such accumulations often exhibit low uranium concentration values but retain their high A.R. values. This serves as a regional indicator of possible uranium accumulations where conditions favor the continued augmentation of the deposit by precipitation from ground water. Where the accumulation is being dispersed and depleted by the ground water system, low A.R. values are observed. Results from the Gulf Coast District of Texas and the Wyoming districts are presented

Characteristics of Earthquake Ground Motion Attenuation in Korea and Japan

International Nuclear Information System (INIS)

Choi, In-Kil; Choun, Young-Sun; Nakajima, Masato; Ohtori, Yasuki; Yun, Kwan-Hee

2006-01-01

The characteristics of a ground motion attenuation in Korea and Japan were estimated by using the earthquake ground motions recorded at the equal distance observation station by KMA, K-NET and KiK-net of Korea and Japan. The ground motion attenuation equations proposed for Korea and Japan were evaluated by comparing the predicted value for the Fukuoka earthquake with the observed records. The predicted values from the attenuation equations show a good agreement with the observed records and each other. It can be concluded from this study that the ground motion attenuation equations can be used for the prediction of strong ground motion attenuation and for an evaluation of the attenuation equations proposed for Korea

Linking Symbolic Interactionism and Grounded Theory Methods in a Research Design

Directory of Open Access Journals (Sweden)

Jennifer Chamberlain-Salaun

2013-09-01

Full Text Available This article focuses on Corbin and Strauss’ evolved version of grounded theory. In the third edition of their seminal text, Basics of Qualitative Research: Techniques and Procedures for Developing Grounded Theory, the authors present 16 assumptions that underpin their conception of grounded theory methodology. The assumptions stem from a symbolic interactionism perspective of social life, including the themes of meaning, action and interaction, self and perspectives. As research design incorporates both methodology and methods, the authors aim to expose the linkages between the 16 assumptions and essential grounded theory methods, highlighting the application of the latter in light of the former. Analyzing the links between symbolic interactionism and essential grounded theory methods provides novice researchers and researchers new to grounded theory with a foundation from which to design an evolved grounded theory research study.

Implications of ground water chemistry and flow patterns for earthquake studies.

Science.gov (United States)

Guangcai, Wang; Zuochen, Zhang; Min, Wang; Cravotta, Charles A; Chenglong, Liu

2005-01-01

Ground water can facilitate earthquake development and respond physically and chemically to tectonism. Thus, an understanding of ground water circulation in seismically active regions is important for earthquake prediction. To investigate the roles of ground water in the development and prediction of earthquakes, geological and hydrogeological monitoring was conducted in a seismogenic area in the Yanhuai Basin, China. This study used isotopic and hydrogeochemical methods to characterize ground water samples from six hot springs and two cold springs. The hydrochemical data and associated geological and geophysical data were used to identify possible relations between ground water circulation and seismically active structural features. The data for delta18O, deltaD, tritium, and 14C indicate ground water from hot springs is of meteoric origin with subsurface residence times of 50 to 30,320 years. The reservoir temperature and circulation depths of the hot ground water are 57 degrees C to 160 degrees C and 1600 to 5000 m, respectively, as estimated by quartz and chalcedony geothermometers and the geothermal gradient. Various possible origins of noble gases dissolved in the ground water also were evaluated, indicating mantle and deep crust sources consistent with tectonically active segments. A hard intercalated stratum, where small to moderate earthquakes frequently originate, is present between a deep (10 to 20 km), high-electrical conductivity layer and the zone of active ground water circulation. The ground water anomalies are closely related to the structural peculiarity of each monitoring point. These results could have implications for ground water and seismic studies in other seismogenic areas.

Application of Electromagnetic Induction to Monitor Changes in Soil Electrical Conductivity Profiles in Arid Agriculture

KAUST Repository

Jadoon, K.Z.; McCabe, Matthew; Moghadas, D.

2015-01-01

In this research, multi-configuration electromagnetic induction (EMI) measurements were conducted in a corn field to estimate variation in soil electrical conductivity profiles in the roots zone. Electromagnetic forward model based on the full

Radioactive waste disposal into the ground

International Nuclear Information System (INIS)

1965-01-01

Disposal into ground has sometimes proved to be an expedient and simple method. Where ground disposal has become an established practice, the sites have so far been limited to those remote from population centres; but in other respects, such as in climate and soil conditions, their characteristics vary widely. Experience gained at these sites has illustrated the variety of problems in radioactive waste migration and the resulting pollution and environmental radiation levels that may reasonably be anticipated at other sites, whether remote from population centres or otherwise.

Prospects of protected ground in Russia

Directory of Open Access Journals (Sweden)

M. I. Mamedov

2014-01-01

Full Text Available The article analyzes the current state and prospects of  protected  ground development in the Russian Federation based on the data of the Ministry  of Agriculture and  the Federal State Statistics Service. The indexes of production of vegetable crops in different regions of the  Russian Federation are given. The problems, which  are  holding back the greenhouse business, are  discussed. The possibilities of increasing the  area of protected ground and vegetable production are shown.

Ground-Wave Propagation Effects on Transmission Lines through Error Images

Directory of Open Access Journals (Sweden)

Uribe-Campos Felipe Alejandro

2014-07-01

Full Text Available Electromagnetic transient calculation of overhead transmission lines is strongly influenced by the natural resistivity of the ground. This varies from 1-10K (Ω·m depending on several media factors and on the physical composition of the ground. The accuracy on the calculation of a system transient response depends in part in the ground return model, which should consider the line geometry, the electrical resistivity and the frequency dependence of the power source. Up to date, there are only a few reports on the specialized literature about analyzing the effects produced by the presence of an imperfectly conducting ground of transmission lines in a transient state. A broad range analysis of three of the most often used ground-return models for calculating electromagnetic transients of overhead transmission lines is performed in this paper. The behavior of modal propagation in ground is analyzed here into effects of first and second order. Finally, a numerical tool based on relative error images is proposed in this paper as an aid for the analyst engineer to estimate the incurred error by using approximate ground-return models when calculating transients of overhead transmission lines.

Ground effect on a self-propelled undulatory foil

Science.gov (United States)

Zhang, Dong; Chao, Liming; Pan, Guang

2018-04-01

The unsteady ground effect on a self-propelled undulatory foil is numerically investigated in this paper. The situation can be widely found in nature especially for fish swimming near the ground. In this study, frequency varies from 0.1 Hz to 2 Hz and distance from the ground varies from 0.2 L to 1 L. Under most kinematics, the ground has a negative effect on the performance of the foil. The swimming velocity slows down, power spend increases and swimming economy reduces. The higher frequency can produce a larger negative effect. Only at the low frequencies f = 0.1 Hz, 0.25 Hz and 0.5 Hz with distance of 0.2 L the velocity can be enhanced by 18%, 6%, 0.8%, respectively. The lift production is found to be increased. The link between the performance and the wake dynamics is also established by studying the vortex structures.

Engineering uses of physics-based ground motion simulations

Science.gov (United States)

Baker, Jack W.; Luco, Nicolas; Abrahamson, Norman A.; Graves, Robert W.; Maechling, Phillip J.; Olsen, Kim B.

2014-01-01

This paper summarizes validation methodologies focused on enabling ground motion simulations to be used with confidence in engineering applications such as seismic hazard analysis and dynmaic analysis of structural and geotechnical systems. Numberical simullation of ground motion from large erthquakes, utilizing physics-based models of earthquake rupture and wave propagation, is an area of active research in the earth science community. Refinement and validatoin of these models require collaboration between earthquake scientists and engineering users, and testing/rating methodolgies for simulated ground motions to be used with confidence in engineering applications. This paper provides an introduction to this field and an overview of current research activities being coordinated by the Souther California Earthquake Center (SCEC). These activities are related both to advancing the science and computational infrastructure needed to produce ground motion simulations, as well as to engineering validation procedures. Current research areas and anticipated future achievements are also discussed.

Damage Stability Assessment of an HSC after Grounding

DEFF Research Database (Denmark)

Ravn, Erik Sonne; Simonsen, Bo Cerup; Baatrup, Jan

2000-01-01

Currently a substantial effort is done within the International Maritime Organisation (IMO) on revision of the High Speed Craft (HSC) Code. A main issue is the extent of bottom damage and raking damage due to grounding on hard rocks and the corresponding requirements to the damage stability...... of the vessel. It has been found that high-speed craft can experience a damage length up to 100% of the ship length. It has, however, also been argued that the damage stability requirements should reflect the size and probability of the damage with a reduction of the demand for the largest damages.......In the present paper a detailed grounding and damage stability analysis is carried out for two specific HSC, a mono-hull (86 m) and a catamaran (69 m). First various grounding scenarios are considered with different values of the forward speed and ground geometry. The results indicate that 100% bottom damage...

IMPACT OF GEOTHERMAL GRADIENT ON GROUND SOURCE HEAT PUMP SYSTEM MODELING

Directory of Open Access Journals (Sweden)

Tomislav Kurevija

2014-07-01

Full Text Available ndisturbed ground temperature is one of the most crucial thermogeological parameters needed for shallow geothermal resources assessment. Energy considered to be geothermal is energy stored in the ground at depths where solar radiation has no effect. At depth where undisturbed ground temperature occurs there is no influence of seasonal variations in air temperature from surface. Exact temperature value, and depth where it occurs, is functionally dependent on surface climate parameters and thermogeologic properties of ground. After abovementioned depth, increase of ground temperature is solely dependent on geothermal gradient. Accurately determined value of undisturbed ground temperature is beneficial for proper sizing of borehole heat exchangers. On practical example of building which is being heated and cooled with shallow geothermal resource, influences of undisturbed ground temperature and geothermal gradient, on size of borehole heat exchanger are going to be presented. Sizing of borehole heat exchanger was calculated with commercial software Ground Loop Designer (GLD, which uses modified line source and cylinder source solutions of heat conduction in solids.

Procedures for ground-water investigations

International Nuclear Information System (INIS)

1989-09-01

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

Cleanup Verification Package for the 618-8 Burial Ground

International Nuclear Information System (INIS)

Appel, M.J.

2006-01-01

This cleanup verification package documents completion of remedial action for the 618-8 Burial Ground, also referred to as the Solid Waste Burial Ground No. 8, 318-8, and the Early Solid Waste Burial Ground. During its period of operation, the 618-8 site is speculated to have been used to bury uranium-contaminated waste derived from fuel manufacturing, and construction debris from the remodeling of the 313 Building

Cleanup Verification Package for the 618-3 Burial Ground

International Nuclear Information System (INIS)

Appel, M.J.

2006-01-01

This cleanup verification package documents completion of remedial action for the 618-3 Solid Waste Burial Ground, also referred to as Burial Ground Number 3 and the Dry Waste Burial Ground Number 3. During its period of operation, the 618-3 site was used to dispose of uranium-contaminated construction debris from the 311 Building and construction/demolition debris from remodeling of the 313, 303-J and 303-K Buildings

Longevity of Emplacement Drift Ground Support Materials, Rev. 01

International Nuclear Information System (INIS)

David H. Tang

2000-01-01

The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for the selection of materials for ground support that will function throughout the preclosure period of a potential repository at Yucca Mountain. The Development Plan (DP) for this analysis is given in Longevity of Emplacement Drift Ground Support Materials (CRWMS M and O 1999a). The objective of this analysis is to update the previous analysis (CRWMS M and O 2000a) to account for related changes in the Ground Control System Description Document (CRWMS M and O 2000b), the Monitored Geologic Repository Project Description Document (CRWMS M and O 1999b), and in environmental conditions, and to provide updated information on candidate ground support materials. Candidate materials for ground support are carbon steel and cement grout. Steel is mainly used for steel sets, lagging, channel, rock bolts, and wire mesh. Cement grout is only considered in the case of grouted rock bolts. Candidate materials for the emplacement drift invert are carbon steel and crushed rock ballast. Materials are evaluated for the repository emplacement drift environment based on the updated thermal loading condition and waste package design. The analysis consists of the following tasks: (1) Identify factors affecting the longevity of ground support materials for use in emplacement drifts; (2) Review existing documents concerning the behavior of candidate ground support materials during the preclosure period; (3) Evaluate impacts of temperature and radiation effects on mechanical and thermal properties of steel. Assess corrosion potential of steel at emplacement drift environment; (4) Evaluate factors affecting longevity of cement grouts for fully grouted rock bolt system. Provide updated information on cement grout mix design for fully grouted rock bolt system; and (5) Evaluate longevity of materials for the emplacement drift invert

Towards the design of a RF-harvesting EBG ground plane

NARCIS (Netherlands)