WorldWideScience

Sample records for tetrahedral system cu2te2o5x2

  1. Interacting spin-1/2 tetrahedral system Cu2Te2O5X2 (X = Cl, Br)

    DEFF Research Database (Denmark)

    Jensen, Jens

    2009-01-01

    Magnetic ordering and excitations of Cu2Te2O5Cl2 are analyzed in terms of a tetramerized spin model for the tetrahedral Cu clusters of spin 1/2. The mean-field model is able to account for the main properties of the incommensurable magnetic structure observed by Zaharko et al. [Phys. Rev. B 73......-dimensional fashion. Preliminary model calculations for the Cu2Te2O5Br2 system lead to the same conclusion. Udgivelsesdato: 7. Januar...

  2. Anomalous Magnetic Excitations of Cooperative Tetrahedral Spin Clusters

    DEFF Research Database (Denmark)

    Prsa, K.; Rønnow, H.M.; Zaharko, O.

    2009-01-01

    An inelastic neutron scattering study of Cu2Te2O5X2 (X=Cl, Br) shows strong dispersive modes with large energy gaps persisting far above T-N, notably in Cu2Te2O5Br2. The anomalous features: a coexisting unusually weak Goldstone-like mode observed in Cu2Te2O5Cl2 and the size of the energy gaps can...... cannot be explained by existing theories, such as our mean-field or random-phase approximation. We argue that our findings represent a new general type of behavior due to intercluster quantum fluctuations and call for development of a new theoretical approach....

  3. Relativistic Jahn-Teller effect in tetrahedral systems

    International Nuclear Information System (INIS)

    Opalka, Daniel; Domcke, Wolfgang; Segado, Mireia; Poluyanov, Leonid V.

    2010-01-01

    It is shown that orbitally degenerate states in highly symmetric systems are split by Jahn-Teller forces which are of relativistic origin (that is, they arise from the spin-orbit coupling operator). For the example of tetrahedral systems, the relativistic Jahn-Teller Hamiltonians of orbitally degenerate electronic states with spin 1/2 are derived. While both electrostatic and relativistic forces contribute to the Jahn-Teller activity of vibrational modes of E and T 2 symmetry in 2 T 2 states of tetrahedral systems, the electrostatic and relativistic Jahn-Teller couplings are complementary for 2 E states: The E mode is Jahn-Teller active through electrostatic forces, while the T 2 mode is Jahn-Teller active through the relativistic forces. The relativistic Jahn-Teller parameters have been computed with ab initio relativistic electronic-structure methods. It is shown for the example of the tetrahedral cluster cations of the group V elements that the relativistic Jahn-Teller couplings can be of the same order of magnitude as the familiar electrostatic Jahn-Teller couplings for the heavier elements.

  4. Calculation of fluctuations and photoemission properties in a tetrahedral-cluster model for an intermediate-valence system

    International Nuclear Information System (INIS)

    Reich, A.; Falicov, L.M.

    1986-01-01

    An exact solution of a four-site tetrahedral-crystal model, the smallest face-centered-cubic crystal, is presented in the case of an intermediate-valence system. The model consists of the following: (a) one extended orbital and one localized orbital per atom, (b) an interatomic transfer term between extended orbitals, (c) an interatomic hybridization between the localized and extended orbitals, (d) strong intra-atomic Coulomb repulsion between opposite-spin localized states, and (e) intermediate-strength intra-atomic Coulomb repulsion between the localized and extended states. These competing effects are examined as they manifest themselves in the intermediate-valence, photoemission, inverse-photoemission, and thermodynamic properties

  5. Tetrahedral hohlraums at omega

    International Nuclear Information System (INIS)

    Kyrala, G.A.; Goldman, S.R.; Batha, S.H.; Wallace, J.M.; Klare, K.A.; Schappert, G.T.; Oertel, J.; Turner, R.E.

    2000-01-01

    We have initiated a study of the usefulness of tetrahedrally illuminated spherical hohlraums, using the Omega laser beams, to drive planar shocks in packages that require indirect drive. A first suite of experiments used spherical hohlraums with a 2-μm thick gold wall surrounded by a 100-μm thick epoxy layer and had an internal diameter of 2.8 mm. Four laser entrance holes each of diameter 700 μm, located on the tips of a regular tetrahedron were used. The shock velocities and the shock uniformities were measured using optical shock break out techniques. The hohlraum x-ray radiation spectrum was also measured using a 10-channel x-ray detector. Tentatively, peak temperatures approaching 195 eV were achieved and shock speeds of 60 μm/ns were measured, when the hohlraum was driven by 22 kJ of 3 ω radiation. (authors)

  6. Streaming simplification of tetrahedral meshes.

    Science.gov (United States)

    Vo, Huy T; Callahan, Steven P; Lindstrom, Peter; Pascucci, Valerio; Silva, Cláudio T

    2007-01-01

    Unstructured tetrahedral meshes are commonly used in scientific computing to represent scalar, vector, and tensor fields in three dimensions. Visualization of these meshes can be difficult to perform interactively due to their size and complexity. By reducing the size of the data, we can accomplish real-time visualization necessary for scientific analysis. We propose a two-step approach for streaming simplification of large tetrahedral meshes. Our algorithm arranges the data on disk in a streaming, I/O-efficient format that allows coherent access to the tetrahedral cells. A quadric-based simplification is sequentially performed on small portions of the mesh in-core. Our output is a coherent streaming mesh which facilitates future processing. Our technique is fast, produces high quality approximations, and operates out-of-core to process meshes too large for main memory.

  7. Video Vectorization via Tetrahedral Remeshing.

    Science.gov (United States)

    Wang, Chuan; Zhu, Jie; Guo, Yanwen; Wang, Wenping

    2017-02-09

    We present a video vectorization method that generates a video in vector representation from an input video in raster representation. A vector-based video representation offers the benefits of vector graphics, such as compactness and scalability. The vector video we generate is represented by a simplified tetrahedral control mesh over the spatial-temporal video volume, with color attributes defined at the mesh vertices. We present novel techniques for simplification and subdivision of a tetrahedral mesh to achieve high simplification ratio while preserving features and ensuring color fidelity. From an input raster video, our method is capable of generating a compact video in vector representation that allows a faithful reconstruction with low reconstruction errors.

  8. Vibrational Spectra of Tetrahedral Fullerenes.

    Science.gov (United States)

    Cheng; Li; Tang

    1999-01-01

    From the topological structures of the following classes of tetrahedral fullerenes-(1) Cn(h, h; -i, i), Cn(h, 0; -i, 2i), Cn(2h + i, -h + i; i, i), Cn(h - i, h + 2i; -i, 2i), and Cn(h, i; 0, i) for Td symmetry; (2) Cn(h, k; k, h), Cn(h, k; -h - k, k), and Cn(h, k; -h, h + k) for Th symmetry; (3) Cn(h, k; i, j) for T symmetry-we have obtained theoretically the formulas for the numbers of their IR and Raman active modes for all of the tetrahedral fullerenes through the decomposition of their nuclear motions into irreducible representations by means of group theory. Copyright 1999 Academic Press.

  9. A direct Arbitrary-Lagrangian-Eulerian ADER-WENO finite volume scheme on unstructured tetrahedral meshes for conservative and non-conservative hyperbolic systems in 3D

    Science.gov (United States)

    Boscheri, Walter; Dumbser, Michael

    2014-10-01

    In this paper we present a new family of high order accurate Arbitrary-Lagrangian-Eulerian (ALE) one-step ADER-WENO finite volume schemes for the solution of nonlinear systems of conservative and non-conservative hyperbolic partial differential equations with stiff source terms on moving tetrahedral meshes in three space dimensions. A WENO reconstruction technique is used to achieve high order of accuracy in space, while an element-local space-time Discontinuous Galerkin finite element predictor on moving curved meshes is used to obtain a high order accurate one-step time discretization. Within the space-time predictor the physical element is mapped onto a reference element using a high order isoparametric approach, where the space-time basis and test functions are given by the Lagrange interpolation polynomials passing through a predefined set of space-time nodes. Since our algorithm is cell-centered, the final mesh motion is computed by using a suitable node solver algorithm. A rezoning step as well as a flattener strategy are used in some of the test problems to avoid mesh tangling or excessive element deformations that may occur when the computation involves strong shocks or shear waves. The ALE algorithm presented in this article belongs to the so-called direct ALE methods because the final Lagrangian finite volume scheme is based directly on a space-time conservation formulation of the governing PDE system, with the rezoned geometry taken already into account during the computation of the fluxes. We apply our new high order unstructured ALE schemes to the 3D Euler equations of compressible gas dynamics, for which a set of classical numerical test problems has been solved and for which convergence rates up to sixth order of accuracy in space and time have been obtained. We furthermore consider the equations of classical ideal magnetohydrodynamics (MHD) as well as the non-conservative seven-equation Baer-Nunziato model of compressible multi-phase flows with

  10. Tetrahedrality and hydrogen bonds in water

    Science.gov (United States)

    Székely, Eszter; Varga, Imre K.; Baranyai, András

    2016-06-01

    We carried out extensive calculations of liquid water at different temperatures and pressures using the BK3 model suggested recently [P. T. Kiss and A. Baranyai, J. Chem. Phys. 138, 204507 (2013)]. In particular, we were interested in undercooled regions to observe the propensity of water to form tetrahedral coordination of closest neighbors around a central molecule. We compared the found tetrahedral order with the number of hydrogen bonds and with the partial pair correlation functions unfolded as distributions of the closest, the second closest, etc. neighbors. We found that contrary to the number of hydrogen bonds, tetrahedrality changes substantially with state variables. Not only the number of tetrahedral arrangements increases with lowering the pressure, the density, and the temperature but the domain size of connecting tetrahedral structures as well. The difference in tetrahedrality is very pronounced between the two sides of the Widom line and even more so between the low density amorphous (LDA) and high density amorphous (HDA) phases. We observed that in liquid water and in HDA, the 5th water molecule, contrary to ice and LDA, is positioned between the first and the second coordination shell. We found no convincing evidence of structural heterogeneity or regions referring to structural transition.

  11. Electronic structure of filled tetrahedral semiconductors

    NARCIS (Netherlands)

    Wood, D.M.; Zunger, Alex; Groot, R. de

    1985-01-01

    We discuss the susceptibility of zinc-blende semiconductors to band-structure modification by insertion of small atoms at their tetrahedral interstitial states. GaP is found to become a direct-gap semiconductor with two He atoms present at its interstitial sites; Si does not. Analysis of the factors

  12. Atomic Nuclei with Tetrahedral and Octahedral Symmetries

    International Nuclear Information System (INIS)

    Dudek, J.; Gozdz, A.; Schunck, N.

    2003-01-01

    We present possible manifestations of octahedral and tetrahedral symmetries in nuclei. These symmetries are associated with the O D h and T D d double point groups. Both of them have very characteristic finger-prints in terms of the nucleonic level properties - unique in the Fermionic universe. The tetrahedral symmetry leads to the four-fold degeneracies in the nucleonic spectra; it does not preserve the parity. The octahedral symmetry leads to the four-fold degeneracies in the nucleonic spectra as well but it does preserve the parity. Microscopic predictions have been obtained using mean-field theory based on the relativistic equations and confirmed by using ''traditional'' Schrodinger equation formalism. Calculations are performed in multidimensional deformation spaces using newly designed algorithms. We discuss some experimental fingerprints of the hypothetical new symmetries and possibilities of their verification through experiments. (author)

  13. Practical implementation of tetrahedral mesh reconstruction in emission tomography

    Science.gov (United States)

    Boutchko, R.; Sitek, A.; Gullberg, G. T.

    2013-05-01

    This paper presents a practical implementation of image reconstruction on tetrahedral meshes optimized for emission computed tomography with parallel beam geometry. Tetrahedral mesh built on a point cloud is a convenient image representation method, intrinsically three-dimensional and with a multi-level resolution property. Image intensities are defined at the mesh nodes and linearly interpolated inside each tetrahedron. For the given mesh geometry, the intensities can be computed directly from tomographic projections using iterative reconstruction algorithms with a system matrix calculated using an exact analytical formula. The mesh geometry is optimized for a specific patient using a two stage process. First, a noisy image is reconstructed on a finely-spaced uniform cloud. Then, the geometry of the representation is adaptively transformed through boundary-preserving node motion and elimination. Nodes are removed in constant intensity regions, merged along the boundaries, and moved in the direction of the mean local intensity gradient in order to provide higher node density in the boundary regions. Attenuation correction and detector geometric response are included in the system matrix. Once the mesh geometry is optimized, it is used to generate the final system matrix for ML-EM reconstruction of node intensities and for visualization of the reconstructed images. In dynamic PET or SPECT imaging, the system matrix generation procedure is performed using a quasi-static sinogram, generated by summing projection data from multiple time frames. This system matrix is then used to reconstruct the individual time frame projections. Performance of the new method is evaluated by reconstructing simulated projections of the NCAT phantom and the method is then applied to dynamic SPECT phantom and patient studies and to a dynamic microPET rat study. Tetrahedral mesh-based images are compared to the standard voxel-based reconstruction for both high and low signal-to-noise ratio

  14. Practical implementation of tetrahedral mesh reconstruction in emission tomography

    International Nuclear Information System (INIS)

    Boutchko, R; Gullberg, G T; Sitek, A

    2013-01-01

    This paper presents a practical implementation of image reconstruction on tetrahedral meshes optimized for emission computed tomography with parallel beam geometry. Tetrahedral mesh built on a point cloud is a convenient image representation method, intrinsically three-dimensional and with a multi-level resolution property. Image intensities are defined at the mesh nodes and linearly interpolated inside each tetrahedron. For the given mesh geometry, the intensities can be computed directly from tomographic projections using iterative reconstruction algorithms with a system matrix calculated using an exact analytical formula. The mesh geometry is optimized for a specific patient using a two stage process. First, a noisy image is reconstructed on a finely-spaced uniform cloud. Then, the geometry of the representation is adaptively transformed through boundary-preserving node motion and elimination. Nodes are removed in constant intensity regions, merged along the boundaries, and moved in the direction of the mean local intensity gradient in order to provide higher node density in the boundary regions. Attenuation correction and detector geometric response are included in the system matrix. Once the mesh geometry is optimized, it is used to generate the final system matrix for ML-EM reconstruction of node intensities and for visualization of the reconstructed images. In dynamic PET or SPECT imaging, the system matrix generation procedure is performed using a quasi-static sinogram, generated by summing projection data from multiple time frames. This system matrix is then used to reconstruct the individual time frame projections. Performance of the new method is evaluated by reconstructing simulated projections of the NCAT phantom and the method is then applied to dynamic SPECT phantom and patient studies and to a dynamic microPET rat study. Tetrahedral mesh-based images are compared to the standard voxel-based reconstruction for both high and low signal-to-noise ratio

  15. ALGORITHMS FOR TETRAHEDRAL NETWORK (TEN) GENERATION

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The Tetrahedral Network(TEN) is a powerful 3-D vector structure in GIS, which has a lot of advantages such as simple structure, fast topological relation processing and rapid visualization. The difficulty of TEN application is automatic creating data structure. Al though a raster algorithm has been introduced by some authors, the problems in accuracy, memory requirement, speed and integrity are still existent. In this paper, the raster algorithm is completed and a vector algorithm is presented after a 3-D data model and structure of TEN have been introducted. Finally, experiment, conclusion and future work are discussed.

  16. Tetrahedral hydrocarbon nanoparticles in space: X-ray spectra

    Science.gov (United States)

    Bilalbegović, G.; Maksimović, A.; Valencic, L. A.

    2018-06-01

    It has been proposed, or confirmed, that diamond nanoparticles exist in various environments in space: close to active galactic nuclei, in the vicinity of supernovae and pulsars, in the interior of several planets in the Solar system, in carbon planets, and other exoplanets, carbon-rich stars, meteorites, in X-ray active Herbig Ae/Be stars, and in the interstellar medium. Using density functional theory methods, we calculate the carbon K-edge X-ray absorption spectrum of two large tetrahedral nanodiamonds: C26H32 and C51H52. We also study and test our methods on the astrophysical molecule CH4, the smallest C-H tetrahedral structure. A possible detection of nanodiamonds from X-ray spectra by future telescopes, such as the project Arcus, is proposed. Simulated spectra of the diffuse interstellar medium using Cyg X-2 as a source show that nanodiamonds studied in this work can be detected by Arcus, a high-resolution X-ray spectrometer mission selected by NASA for a Phase A concept study.

  17. Feature-Sensitive Tetrahedral Mesh Generation with Guaranteed Quality

    OpenAIRE

    Wang, Jun; Yu, Zeyun

    2012-01-01

    Tetrahedral meshes are being extensively used in finite element methods (FEM). This paper proposes an algorithm to generate feature-sensitive and high-quality tetrahedral meshes from an arbitrary surface mesh model. A top-down octree subdivision is conducted on the surface mesh and a set of tetrahedra are constructed using adaptive body-centered cubic (BCC) lattices. Special treatments are given to the tetrahedra near the surface such that the quality of the resulting tetrahedral mesh is prov...

  18. Determination of the population of octahedral and tetrahedral interstitials in zirconium hydrides

    International Nuclear Information System (INIS)

    Fedorov, V.M.; Gogava, V.V.; Shilo, S.I.; Biryukova, E.A.

    1983-01-01

    Results of neutron investigations of ZrHsub(1.66), ZrHsub(1.75) and ZrHsub(1.98) zirconium hydrides are presented. Investigations were conducted using plane polycrystal samples by multidetector system of scattered neutron detection. Neutron diffraction method was used to determine the number of interstitial hydrogen atoms in interstitials of the lattice cell in the case of statistic atom distribution. The numbers of interstitial atoms in octahedral interstitials for zirconium hydrides were determined experimentally; the difference of potential energies of hydrogen atoms in octa- and tetrahedral interstitials was determined as well. It is shown that experimentally determined difference of potential energies of hydrogen atoms, occupying octa- and tetrahedral positions in investigated zirconium hydrides results at room temperature in the pretailing occupation of tetrahedral interstitials by hydrogen atoms (85-90%); the occupation number grows with temperature decrease and the ordering of interstitial vacancies with formation of hydrogen superstructure takes place at low temperatures

  19. 3He/4He production ratios by tetrahedral symmetric condensation

    International Nuclear Information System (INIS)

    Takahashi, Akito

    2006-01-01

    The present paper treats application of the Electronic Quasi-Particle Expansion Theory (EQPET) model for Tetrahedral Symmetric Condensate (TSC) of H/D mixed systems for Pd host metal. Production ratios of 3 He/ 4 He for multi-body fusion reactions in H/D mixed TSC systems are calculated as a function of H/D mixing ratio. The model is further extended to treat direct nuclear interactions between host-metal nucleus and TSC of pure four protons (or four deuterons), since TSC can become very small (far less than 1 pm radius) charge-neutral pseudo-particle. Results for the case of Ni + 4p/TSC are discussed with Ni + p capture reactions and Ni + 4p fission reactions. (authors)

  20. DNA tetrahedral scaffolds-based platform for the construction of electrochemiluminescence biosensor.

    Science.gov (United States)

    Feng, Qiu-Mei; Zhou, Zhen; Li, Mei-Xing; Zhao, Wei; Xu, Jing-Juan; Chen, Hong-Yuan

    2017-04-15

    Proximal metallic nanoparticles (NPs) could quench the electrochemiluminescence (ECL) emission of semiconductor quantum dots (QDs) due to Förster energy transfer (FRET), but at a certain distance, the coupling of light-emission with surface plasmon resonance (SPR) result in enhanced ECL. Thus, the modification strategies and distances control between QDs and metallic NPs are critical for the ECL intensity of QDs. In this strategy, a SPR enhanced ECL sensor based on DNA tetrahedral scaffolds modified platform was reported for the detection of telomerase activity. Due to the rigid three-dimensional structure, DNA tetrahedral scaffolds grafting on the electrode surface could accurately modulate the distance between CdS QDs and luminol labelled gold nanoparticles (L-Au NPs), meanwhile provide an enhanced spatial dimension and accessibility for the assembly of multiple L-Au NPs. The ECL intensities of both CdS QDs (-1.25V vs. SCE) and luminol (+0.33V vs. SCE) gradually increased along with the formation of multiple L-Au NPs at the vertex of DNA tetrahedral scaffolds induced by telomerase, bringing in a dual-potential ECL analysis. The proposed method showed high sensitivity for the identification of telomerase and was successfully applied for the differentiation of cancer cells from normal cells. This work suggests that DNA tetrahedral scaffolds could serve as an excellent choice for the construction of SPR-ECL system. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. A geometric toolbox for tetrahedral finite element partitions

    NARCIS (Netherlands)

    Brandts, J.; Korotov, S.; Křížek, M.; Axelsson, O.; Karátson, J.

    2011-01-01

    In this work we present a survey of some geometric results on tetrahedral partitions and their refinements in a unified manner. They can be used for mesh generation and adaptivity in practical calculations by the finite element method (FEM), and also in theoretical finite element (FE) analysis.

  2. Tetrahedral meshing via maximal Poisson-disk sampling

    KAUST Repository

    Guo, Jianwei; Yan, Dongming; Chen, Li; Zhang, Xiaopeng; Deussen, Oliver; Wonka, Peter

    2016-01-01

    -distributed point sets in arbitrary domains. We first perform MPS on the boundary of the input domain, we then sample the interior of the domain, and we finally extract the tetrahedral mesh from the samples by using 3D Delaunay or regular triangulation for uniform

  3. Tetrahedral meshing via maximal Poisson-disk sampling

    KAUST Repository

    Guo, Jianwei

    2016-02-15

    In this paper, we propose a simple yet effective method to generate 3D-conforming tetrahedral meshes from closed 2-manifold surfaces. Our approach is inspired by recent work on maximal Poisson-disk sampling (MPS), which can generate well-distributed point sets in arbitrary domains. We first perform MPS on the boundary of the input domain, we then sample the interior of the domain, and we finally extract the tetrahedral mesh from the samples by using 3D Delaunay or regular triangulation for uniform or adaptive sampling, respectively. We also propose an efficient optimization strategy to protect the domain boundaries and to remove slivers to improve the meshing quality. We present various experimental results to illustrate the efficiency and the robustness of our proposed approach. We demonstrate that the performance and quality (e.g., minimal dihedral angle) of our approach are superior to current state-of-the-art optimization-based approaches.

  4. A computational study of nodal-based tetrahedral element behavior.

    Energy Technology Data Exchange (ETDEWEB)

    Gullerud, Arne S.

    2010-09-01

    This report explores the behavior of nodal-based tetrahedral elements on six sample problems, and compares their solution to that of a corresponding hexahedral mesh. The problems demonstrate that while certain aspects of the solution field for the nodal-based tetrahedrons provide good quality results, the pressure field tends to be of poor quality. Results appear to be strongly affected by the connectivity of the tetrahedral elements. Simulations that rely on the pressure field, such as those which use material models that are dependent on the pressure (e.g. equation-of-state models), can generate erroneous results. Remeshing can also be strongly affected by these issues. The nodal-based test elements as they currently stand need to be used with caution to ensure that their numerical deficiencies do not adversely affect critical values of interest.

  5. Tetrahedral gray code for visualization of genome information.

    Directory of Open Access Journals (Sweden)

    Natsuhiro Ichinose

    Full Text Available We propose a tetrahedral Gray code that facilitates visualization of genome information on the surfaces of a tetrahedron, where the relative abundance of each [Formula: see text]-mer in the genomic sequence is represented by a color of the corresponding cell of a triangular lattice. For biological significance, the code is designed such that the [Formula: see text]-mers corresponding to any adjacent pair of cells differ from each other by only one nucleotide. We present a simple procedure to draw such a pattern on the development surfaces of a tetrahedron. The thus constructed tetrahedral Gray code can demonstrate evolutionary conservation and variation of the genome information of many organisms at a glance. We also apply the tetrahedral Gray code to the honey bee (Apis mellifera genome to analyze its methylation structure. The results indicate that the honey bee genome exhibits CpG overrepresentation in spite of its methylation ability and that two conserved motifs, CTCGAG and CGCGCG, in the unmethylated regions are responsible for the overrepresentation of CpG.

  6. Shutdown dose rate analysis with CAD geometry, Cartesian/tetrahedral mesh, and advanced variance reduction

    International Nuclear Information System (INIS)

    Biondo, Elliott D.; Davis, Andrew; Wilson, Paul P.H.

    2016-01-01

    Highlights: • A CAD-based shutdown dose rate analysis workflow has been implemented. • Cartesian and superimposed tetrahedral mesh are fully supported. • Biased and unbiased photon source sampling options are available. • Hybrid Monte Carlo/deterministic techniques accelerate photon transport. • The workflow has been validated with the FNG-ITER benchmark problem. - Abstract: In fusion energy systems (FES) high-energy neutrons born from burning plasma activate system components to form radionuclides. The biological dose rate that results from photons emitted by these radionuclides after shutdown—the shutdown dose rate (SDR)—must be quantified for maintenance planning. This can be done using the Rigorous Two-Step (R2S) method, which involves separate neutron and photon transport calculations, coupled by a nuclear inventory analysis code. The geometric complexity and highly attenuating configuration of FES motivates the use of CAD geometry and advanced variance reduction for this analysis. An R2S workflow has been created with the new capability of performing SDR analysis directly from CAD geometry with Cartesian or tetrahedral meshes and with biased photon source sampling, enabling the use of the Consistent Adjoint Driven Importance Sampling (CADIS) variance reduction technique. This workflow has been validated with the Frascati Neutron Generator (FNG)-ITER SDR benchmark using both Cartesian and tetrahedral meshes and both unbiased and biased photon source sampling. All results are within 20.4% of experimental values, which constitutes satisfactory agreement. Photon transport using CADIS is demonstrated to yield speedups as high as 8.5·10"5 for problems using the FNG geometry.

  7. Electromagnetic forward modelling for realistic Earth models using unstructured tetrahedral meshes and a meshfree approach

    Science.gov (United States)

    Farquharson, C.; Long, J.; Lu, X.; Lelievre, P. G.

    2017-12-01

    Real-life geology is complex, and so, even when allowing for the diffusive, low resolution nature of geophysical electromagnetic methods, we need Earth models that can accurately represent this complexity when modelling and inverting electromagnetic data. This is particularly the case for the scales, detail and conductivity contrasts involved in mineral and hydrocarbon exploration and development, but also for the larger scale of lithospheric studies. Unstructured tetrahedral meshes provide a flexible means of discretizing a general, arbitrary Earth model. This is important when wanting to integrate a geophysical Earth model with a geological Earth model parameterized in terms of surfaces. Finite-element and finite-volume methods can be derived for computing the electric and magnetic fields in a model parameterized using an unstructured tetrahedral mesh. A number of such variants have been proposed and have proven successful. However, the efficiency and accuracy of these methods can be affected by the "quality" of the tetrahedral discretization, that is, how many of the tetrahedral cells in the mesh are long, narrow and pointy. This is particularly the case if one wants to use an iterative technique to solve the resulting linear system of equations. One approach to deal with this issue is to develop sophisticated model and mesh building and manipulation capabilities in order to ensure that any mesh built from geological information is of sufficient quality for the electromagnetic modelling. Another approach is to investigate other methods of synthesizing the electromagnetic fields. One such example is a "meshfree" approach in which the electromagnetic fields are synthesized using a mesh that is distinct from the mesh used to parameterized the Earth model. There are then two meshes, one describing the Earth model and one used for the numerical mathematics of computing the fields. This means that there are no longer any quality requirements on the model mesh, which

  8. Electron emission induced modifications in amorphous tetrahedral diamondlike carbon

    International Nuclear Information System (INIS)

    Mercer, T.W.; DiNardo, N.J.; Rothman, J.B.; Siegal, M.P.; Friedmann, T.A.; Martinez-Miranda, L.J.

    1998-01-01

    The cold-cathode electron emission properties of amorphous tetrahedral diamondlike carbon are promising for flat-panel display and vacuum microelectronics technologies. The onset of electron emission is, typically, preceded by open-quotes conditioningclose quotes where the material is stressed by an applied electric field. To simulate conditioning and assess its effect, we combined the spatially localized field and current of a scanning tunneling microscope tip with high-spatial-resolution characterization. Scanning force microscopy shows that conditioning alters surface morphology and electronic structure. Spatially resolved electron-energy-loss spectroscopy indicates that the predominant bonding configuration changes from predominantly fourfold to threefold coordination. copyright 1998 American Institute of Physics

  9. Magnetic Grüneisen parameter and magnetocaloric properties of a coupled spin–electron double-tetrahedral chain

    International Nuclear Information System (INIS)

    Gálisová, Lucia; Strečka, Jozef

    2015-01-01

    Magnetocaloric effect in a double-tetrahedral chain, in which nodal lattice sites occupied by the localized Ising spins regularly alternate with three equivalent lattice sites available for mobile electrons, is exactly investigated by considering the one-third electron filling and the ferromagnetic Ising exchange interaction between the mobile electrons and their nearest Ising neighbours. The entropy and the magnetic Grüneisen parameter, which closely relate to the magnetocaloric effect, are exactly calculated in order to investigate the relation between the ground-state degeneracy and the cooling efficiency of the hybrid spin–electron system during the adiabatic demagnetization. - Highlights: • A double-tetrahedral chain of mobile electrons and localized Ising spins is studied. • Magnetic Grüneisen parameter for the system is exactly derived. • Macroscopically degenerate phases FRU and FM constitute the ground state. • MCE is three times higher nearby FRU–FM transition than in FRU phase at small fields

  10. Artificial intelligence approach to planning the robotic assembly of large tetrahedral truss structures

    Science.gov (United States)

    Homemdemello, Luiz S.

    1992-01-01

    An assembly planner for tetrahedral truss structures is presented. To overcome the difficulties due to the large number of parts, the planner exploits the simplicity and uniformity of the shapes of the parts and the regularity of their interconnection. The planning automation is based on the computational formalism known as production system. The global data base consists of a hexagonal grid representation of the truss structure. This representation captures the regularity of tetrahedral truss structures and their multiple hierarchies. It maps into quadratic grids and can be implemented in a computer by using a two-dimensional array data structure. By maintaining the multiple hierarchies explicitly in the model, the choice of a particular hierarchy is only made when needed, thus allowing a more informed decision. Furthermore, testing the preconditions of the production rules is simple because the patterned way in which the struts are interconnected is incorporated into the topology of the hexagonal grid. A directed graph representation of assembly sequences allows the use of both graph search and backtracking control strategies.

  11. Chemical bonding modifications of tetrahedral amorphous carbon and nitrogenated tetrahedral amorphous carbon films induced by rapid thermal annealing

    International Nuclear Information System (INIS)

    McCann, R.; Roy, S.S.; Papakonstantinou, P.; Bain, M.F.; Gamble, H.S.; McLaughlin, J.A.

    2005-01-01

    Tetrahedral amorphous carbon (ta-C) and nitrogenated tetrahedral amorphous carbon films (ta-CN x ), deposited by double bend off plane Filtered Vacuum Cathodic Arc were annealed up to 1000 deg. C in flowing argon for 2 min. Modifications on the chemical bonding structure of the rapidly annealed films, as a function of temperature, were investigated by NEXAFS, X-ray photoelectron and Raman spectroscopies. The interpretation of these spectra is discussed. The results demonstrate that the structure of undoped ta-C films prepared at floating potential with an arc current of 80 A remains stable up to 900 deg. C, whereas that of ta-CN x containing 12 at.% nitrogen is stable up to 700 deg. C. At higher temperatures, all the spectra indicated the predominant formation of graphitic carbon. Through NEXAFS studies, we clearly observed three π* resonance peaks at the ' N K edge structure. The origin of these three peaks is not well established in the literature. However our temperature-dependant study ascertained that the first peak originates from C=N bonds and the third peak originates from the incorporation of nitrogen into the graphite like domains

  12. Nuclear tetrahedral symmetry: possibly present throughout the periodic table.

    Science.gov (United States)

    Dudek, J; Goźdź, A; Schunck, N; Miśkiewicz, M

    2002-06-24

    More than half a century after the fundamental, spherical shell structure in nuclei had been established, theoretical predictions indicated that the shell gaps comparable or even stronger than those at spherical shapes may exist. Group-theoretical analysis supported by realistic mean-field calculations indicate that the corresponding nuclei are characterized by the TD(d) ("double-tetrahedral") symmetry group. Strong shell-gap structure is enhanced by the existence of the four-dimensional irreducible representations of TD(d); it can be seen as a geometrical effect that does not depend on a particular realization of the mean field. Possibilities of discovering the TD(d) symmetry in experiment are discussed.

  13. Modeling amorphization of tetrahedral structures under local approaches

    International Nuclear Information System (INIS)

    Jesurum, C.E.; Pulim, V.; Berger, B.; Hobbs, L.W.

    1997-01-01

    Many crystalline ceramics can be topologically disordered (amorphized) by disordering radiation events involving high-energy collision cascades or (in some cases) successive single-atom displacements. The authors are interested in both the potential for disorder and the possible aperiodic structures adopted following the disordering event. The potential for disordering is related to connectivity, and among those structures of interest are tetrahedral networks (such as SiO 2 , SiC and Si 3 N 4 ) comprising corner-shared tetrahedral units whose connectivities are easily evaluated. In order to study the response of these networks to radiation, the authors have chosen to model their assembly according to the (simple) local rules that each corner obeys in connecting to another tetrahedron; in this way they easily erect large computer models of any crystalline polymorphic form. Amorphous structures can be similarly grown by application of altered rules. They have adopted a simple model of irradiation in which all bonds in the neighborhood of a designated tetrahedron are destroyed, and they reform the bonds in this region according to a set of (possibly different) local rules appropriate to the environmental conditions. When a tetrahedron approaches the boundary of this neighborhood, it undergoes an optimization step in which a spring is inserted between two corners of compatible tetrahedra when they are within a certain distance of one another; component forces are then applied that act to minimize the distance between these corners and minimize the deviation from the rules. The resulting structure is then analyzed for the complete adjacency matrix, irreducible ring statistics, and bond angle distributions

  14. Single walled carbon nanotube network—Tetrahedral amorphous carbon composite film

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Ajai, E-mail: ajai.iyer@aalto.fi; Liu, Xuwen; Koskinen, Jari [Department of Materials Science and Engineering, School of Chemical Technology, Aalto University, POB 16200, 00076 Espoo (Finland); Kaskela, Antti; Kauppinen, Esko I. [NanoMaterials Group, Department of Applied Physics, School of Science, Aalto University, POB 15100, 00076 Espoo (Finland); Johansson, Leena-Sisko [Department of Forest Products Technology, School of Chemical Technology, Aalto University, POB 16400, 00076 Espoo (Finland)

    2015-06-14

    Single walled carbon nanotube network (SWCNTN) was coated by tetrahedral amorphous carbon (ta-C) using a pulsed Filtered Cathodic Vacuum Arc system to form a SWCNTN—ta-C composite film. The effects of SWCNTN areal coverage density and ta-C coating thickness on the composite film properties were investigated. X-Ray photoelectron spectroscopy measurements prove the presence of high quality sp{sup 3} bonded ta-C coating on the SWCNTN. Raman spectroscopy suggests that the single wall carbon nanotubes (SWCNTs) forming the network survived encapsulation in the ta-C coating. Nano-mechanical testing suggests that the ta-C coated SWCNTN has superior wear performance compared to uncoated SWCNTN.

  15. First-principles study of anharmonic phonon effects in tetrahedral semiconductors via an external electric field

    Energy Technology Data Exchange (ETDEWEB)

    Dabiri, Zohreh, E-mail: z.dabiri@stu.yazd.ac.ir [Physics Department, Yazd University, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of); Kazempour, Ali [Department of Physics, Payame Noor University, P.O. BOX 119395-3697, Tehran (Iran, Islamic Republic of); Nano Structured Coatings Institute of Yazd Payame Noor University, P.O. Code 89431-74559, Yazd (Iran, Islamic Republic of); Sadeghzadeh, Mohammad Ali [Physics Department, Yazd University, P.O. Box 89195-741, Yazd (Iran, Islamic Republic of)

    2016-11-15

    The strength of phonon anharmonicity is investigated in the framework of the Density Functional Perturbation Theory via an applied constant electric field. In contrast to routine approaches, we have employed the electric field as an effective probe to quest after the quasi-harmonic and anharmonic effects. Two typical tetrahedral semiconductors (diamond and silicon) have been selected to test the efficiency of this approach. In this scheme the applied field is responsible for establishing the perturbation and also inducing the anharmonicity in systems. The induced polarization is a result of changing the electronic density while ions are located at their ground state coordinates or at a specified strain. Employing this method, physical quantities of the semiconductors are calculated in presence of the electron–phonon interaction directly and, phonon–phonon interaction, indirectly. The present approach, which is in good agreement with previous theoretical and experimental studies, can be introduced as a benchmark to simply investigate the anharmonicity and pertinent consequences in materials.

  16. Three-dimensional modeling of capsule implosions in OMEGA tetrahedral hohlraums

    International Nuclear Information System (INIS)

    Schnittman, J. D.; Craxton, R. S.

    2000-01-01

    Tetrahedral hohlraums have been proposed as a means for achieving the highly uniform implosions needed for ignition with inertial confinement fusion (ICF) [J. D. Schnittman and R. S. Craxton, Phys. Plasmas 3, 3786 (1996)]. Recent experiments on the OMEGA laser system have achieved good drive uniformity consistent with theoretical predictions [J. M. Wallace et al., Phys. Rev. Lett. 82, 3807 (1999)]. To better understand these experiments and future investigations of high-convergence ICF implosions, the three-dimensional (3-D) view-factor code BUTTERCUP has been expanded to model the time-dependent radiation transport in the hohlraum and the hydrodynamic implosion of the capsule. Additionally, a 3-D postprocessor has been written to simulate x-ray images of the imploded core. Despite BUTTERCUP's relative simplicity, its predictions for radiation drive temperatures, fusion yields, and core deformation show close agreement with experiment. (c) 2000 American Institute of Physics

  17. Evaluation of a 3D point cloud tetrahedral tomographic reconstruction method

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, N F; Sitek, A, E-mail: nfp4@bwh.harvard.ed, E-mail: asitek@bwh.harvard.ed [Department of Radiology, Brigham and Women' s Hospital-Harvard Medical School Boston, MA (United States)

    2010-09-21

    Tomographic reconstruction on an irregular grid may be superior to reconstruction on a regular grid. This is achieved through an appropriate choice of the image space model, the selection of an optimal set of points and the use of any available prior information during the reconstruction process. Accordingly, a number of reconstruction-related parameters must be optimized for best performance. In this work, a 3D point cloud tetrahedral mesh reconstruction method is evaluated for quantitative tasks. A linear image model is employed to obtain the reconstruction system matrix and five point generation strategies are studied. The evaluation is performed using the recovery coefficient, as well as voxel- and template-based estimates of bias and variance measures, computed over specific regions in the reconstructed image. A similar analysis is performed for regular grid reconstructions that use voxel basis functions. The maximum likelihood expectation maximization reconstruction algorithm is used. For the tetrahedral reconstructions, of the five point generation methods that are evaluated, three use image priors. For evaluation purposes, an object consisting of overlapping spheres with varying activity is simulated. The exact parallel projection data of this object are obtained analytically using a parallel projector, and multiple Poisson noise realizations of these exact data are generated and reconstructed using the different point generation strategies. The unconstrained nature of point placement in some of the irregular mesh-based reconstruction strategies has superior activity recovery for small, low-contrast image regions. The results show that, with an appropriately generated set of mesh points, the irregular grid reconstruction methods can out-perform reconstructions on a regular grid for mathematical phantoms, in terms of the performance measures evaluated.

  18. Evaluation of a 3D point cloud tetrahedral tomographic reconstruction method

    Science.gov (United States)

    Pereira, N. F.; Sitek, A.

    2010-09-01

    Tomographic reconstruction on an irregular grid may be superior to reconstruction on a regular grid. This is achieved through an appropriate choice of the image space model, the selection of an optimal set of points and the use of any available prior information during the reconstruction process. Accordingly, a number of reconstruction-related parameters must be optimized for best performance. In this work, a 3D point cloud tetrahedral mesh reconstruction method is evaluated for quantitative tasks. A linear image model is employed to obtain the reconstruction system matrix and five point generation strategies are studied. The evaluation is performed using the recovery coefficient, as well as voxel- and template-based estimates of bias and variance measures, computed over specific regions in the reconstructed image. A similar analysis is performed for regular grid reconstructions that use voxel basis functions. The maximum likelihood expectation maximization reconstruction algorithm is used. For the tetrahedral reconstructions, of the five point generation methods that are evaluated, three use image priors. For evaluation purposes, an object consisting of overlapping spheres with varying activity is simulated. The exact parallel projection data of this object are obtained analytically using a parallel projector, and multiple Poisson noise realizations of these exact data are generated and reconstructed using the different point generation strategies. The unconstrained nature of point placement in some of the irregular mesh-based reconstruction strategies has superior activity recovery for small, low-contrast image regions. The results show that, with an appropriately generated set of mesh points, the irregular grid reconstruction methods can out-perform reconstructions on a regular grid for mathematical phantoms, in terms of the performance measures evaluated.

  19. Evaluation of a 3D point cloud tetrahedral tomographic reconstruction method

    International Nuclear Information System (INIS)

    Pereira, N F; Sitek, A

    2010-01-01

    Tomographic reconstruction on an irregular grid may be superior to reconstruction on a regular grid. This is achieved through an appropriate choice of the image space model, the selection of an optimal set of points and the use of any available prior information during the reconstruction process. Accordingly, a number of reconstruction-related parameters must be optimized for best performance. In this work, a 3D point cloud tetrahedral mesh reconstruction method is evaluated for quantitative tasks. A linear image model is employed to obtain the reconstruction system matrix and five point generation strategies are studied. The evaluation is performed using the recovery coefficient, as well as voxel- and template-based estimates of bias and variance measures, computed over specific regions in the reconstructed image. A similar analysis is performed for regular grid reconstructions that use voxel basis functions. The maximum likelihood expectation maximization reconstruction algorithm is used. For the tetrahedral reconstructions, of the five point generation methods that are evaluated, three use image priors. For evaluation purposes, an object consisting of overlapping spheres with varying activity is simulated. The exact parallel projection data of this object are obtained analytically using a parallel projector, and multiple Poisson noise realizations of these exact data are generated and reconstructed using the different point generation strategies. The unconstrained nature of point placement in some of the irregular mesh-based reconstruction strategies has superior activity recovery for small, low-contrast image regions. The results show that, with an appropriately generated set of mesh points, the irregular grid reconstruction methods can out-perform reconstructions on a regular grid for mathematical phantoms, in terms of the performance measures evaluated.

  20. A suitable low-order, eight-node tetrahedral finite element for solids

    Energy Technology Data Exchange (ETDEWEB)

    Key, S.W.; Heinstein, M.S.; Stone, C.M.; Mello, F.J.; Blanford, M.L.; Budge, K.G.

    1998-03-01

    To use the all-tetrahedral mesh generation existing today, the authors have explored the creation of a computationally efficient eight-node tetrahedral finite element (a four-node tetrahedral finite element enriched with four mid-face nodal points). The derivation of the element`s gradient operator, studies in obtaining a suitable mass lumping, and the element`s performance in applications are presented. In particular they examine the eight-node tetrahedral finite element`s behavior in longitudinal plane wave propagation, in transverse cylindrical wave propagation, and in simulating Taylor bar impacts. The element samples only constant strain states and, therefore, has 12 hour-glass modes. In this regard it bears similarities to the eight-node, mean-quadrature hexahedral finite element. Comparisons with the results obtained from the mean-quadrature eight-node hexahedral finite element and the four-node tetrahedral finite element are included. Given automatic all-tetrahedral meshing, the eight-node, constant-strain tetrahedral finite element is a suitable replacement for the eight-node hexahedral finite element in those cases where mesh generation requires an inordinate amount of user intervention and direction to obtain acceptable mesh properties.

  1. A suitable low-order, eight-node tetrahedral finite element for solids

    International Nuclear Information System (INIS)

    Key, S.W.; Heinstein, M.S.; Stone, C.M.; Mello, F.J.; Blanford, M.L.; Budge, K.G.

    1998-03-01

    To use the all-tetrahedral mesh generation existing today, the authors have explored the creation of a computationally efficient eight-node tetrahedral finite element (a four-node tetrahedral finite element enriched with four mid-face nodal points). The derivation of the element's gradient operator, studies in obtaining a suitable mass lumping, and the element's performance in applications are presented. In particular they examine the eight-node tetrahedral finite element's behavior in longitudinal plane wave propagation, in transverse cylindrical wave propagation, and in simulating Taylor bar impacts. The element samples only constant strain states and, therefore, has 12 hour-glass modes. In this regard it bears similarities to the eight-node, mean-quadrature hexahedral finite element. Comparisons with the results obtained from the mean-quadrature eight-node hexahedral finite element and the four-node tetrahedral finite element are included. Given automatic all-tetrahedral meshing, the eight-node, constant-strain tetrahedral finite element is a suitable replacement for the eight-node hexahedral finite element in those cases where mesh generation requires an inordinate amount of user intervention and direction to obtain acceptable mesh properties

  2. Polyamorphism in tetrahedral substances: Similarities between silicon and ice

    Science.gov (United States)

    Garcez, K. M. S.; Antonelli, A.

    2015-07-01

    Tetrahedral substances, such as silicon, water, germanium, and silica, share various unusual phase behaviors. Among them, the so-called polyamorphism, i.e., the existence of more than one amorphous form, has been intensively investigated in the last three decades. In this work, we study the metastable relations between amorphous states of silicon in a wide range of pressures, using Monte Carlo simulations. Our results indicate that the two amorphous forms of silicon at high pressures, the high density amorphous (HDA) and the very high density amorphous (VHDA), can be decompressed from high pressure (˜20 GPa) down to the tensile regime, where both convert into the same low density amorphous. Such behavior is also observed in ice. While at high pressure (˜20 GPa), HDA is less stable than VHDA, at the pressure of 10 GPa both forms exhibit similar stability. On the other hand, at much lower pressure (˜5 GPa), HDA and VHDA are no longer the most stable forms, and, upon isobaric annealing, an even less dense form of amorphous silicon emerges, the expanded high density amorphous, again in close similarity to what occurs in ice.

  3. Hydrogen solution in tetrahedral or octahedral interstitial sites in Al

    International Nuclear Information System (INIS)

    Zeng, C.A.; Hu, J.P.; Ouyang, C.Y.

    2011-01-01

    Highlights: → The physical nature of the site preference for H solution in BCC Al is revealed. → The site preference is result of competition between Al-H bonding interaction and local lattice distortion. → The Al-H bonding interaction lowers the solution energy while the local lattice distortion increases the solution energy. - Abstract: It is reported that H atoms prefer to stay at interstitial (defect) sites with larger space in most metals. However, H atom prefers to occupy tetrahedral interstitial sites (T-site) that provide smaller space than octahedral sites (O-site) in Al. This paper studied the H-Al interactions from first principles calculations. Through analysis of the H-induced electronic states and the local atomic relaxations, we show that H-Al bonding interaction is stronger for T-site H, which is in favor of the solution energy. On the other hand, larger local atomic distortion is observed around the T-site H, which increases the total energy.

  4. Fast and Exact Fiber Surfaces for Tetrahedral Meshes.

    Science.gov (United States)

    Klacansky, Pavol; Tierny, Julien; Carr, Hamish; Zhao Geng

    2017-07-01

    Isosurfaces are fundamental geometrical objects for the analysis and visualization of volumetric scalar fields. Recent work has generalized them to bivariate volumetric fields with fiber surfaces, the pre-image of polygons in range space. However, the existing algorithm for their computation is approximate, and is limited to closed polygons. Moreover, its runtime performance does not allow instantaneous updates of the fiber surfaces upon user edits of the polygons. Overall, these limitations prevent a reliable and interactive exploration of the space of fiber surfaces. This paper introduces the first algorithm for the exact computation of fiber surfaces in tetrahedral meshes. It assumes no restriction on the topology of the input polygon, handles degenerate cases and better captures sharp features induced by polygon bends. The algorithm also allows visualization of individual fibers on the output surface, better illustrating their relationship with data features in range space. To enable truly interactive exploration sessions, we further improve the runtime performance of this algorithm. In particular, we show that it is trivially parallelizable and that it scales nearly linearly with the number of cores. Further, we study acceleration data-structures both in geometrical domain and range space and we show how to generalize interval trees used in isosurface extraction to fiber surface extraction. Experiments demonstrate the superiority of our algorithm over previous work, both in terms of accuracy and running time, with up to two orders of magnitude speedups. This improvement enables interactive edits of range polygons with instantaneous updates of the fiber surface for exploration purpose. A VTK-based reference implementation is provided as additional material to reproduce our results.

  5. Controlled synthesis of concave tetrahedral palladium nanocrystals by reducing Pd(acac)2 with carbon monoxide

    International Nuclear Information System (INIS)

    Zhu, Hai; Chi, Quan; Zhao, Yanxi; Li, Chunya; Tang, Heqing; Li, Jinlin; Huang, Tao; Liu, Hanfan

    2012-01-01

    Graphical abstract: By using CO as a reducing agent, uniform and well-defined concave tetrahedral Pd nanocrystals were successfully synthesized. CO flow rate was the most essential for the formation of the concave tetrahedral nanostructures. The morphologies and sizes of the final products can be well controlled by adjusting the flow rate of CO. Highlights: ► By using CO as a reducing agent, concave tetrahedral Pd nanocrystals were obtained. ► CO flow rate is critical to the formation of concave tetrahedral Pd nanocrystals. ► The selective adsorption of CO on (1 1 0) facets is essential to concave Pd tetrahedra. -- Abstract: CO reducing strategy to control the morphologies of palladium nanocrystals was investigated. By using CO as a reducing agent, uniform and well-defined concave tetrahedral Pd nanocrystals with a mean size of about 55 ± 2 nm were readily synthesized with Pd(acac) 2 as a precursor and PVP as a stabilizer. The structures of the as-prepared Pd nanocrystals were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), ultraviolet–visible (UV–vis) absorption spectroscopy and electrochemical measurements. The results demonstrated that CO was the most essential for the formation of the concave tetrahedral Pd nanostructures. The morphologies and sizes of the final products can be well controlled by adjusting the flow rate of CO. The most appropriate CO flow rate, temperature and time for the formation of the ideal concave tetrahedral Pd nanocrystals was 0.033 mL s −1 , 100 °C and 3 h, respectively.

  6. Ab initio investigation of inversion in tetrahedral molecules of transition metals

    International Nuclear Information System (INIS)

    Musaev, D.G.; Boldyrev, A.I.

    1984-01-01

    Tetrahedral and plane square configurations of TiH 4 , TiF 4 , molecules and ScH 4 - , ScF 4 - anions are optimized in the frames of Hartree-Fock-Roothaan method with the bases of DZHD and DZRS type. Inversion barriers of tetrahedral molecules through plane sqUare configuration which make up 46; 70; 27 and 39 kcal/mol in TiH 4 , TiF 4 , SoH 4 - and ScF 4 - respectively are estimated. Correlation diagrams under inversion are analyzed

  7. Physics at low spin in the mass 160 region: the search for tetrahedral shapes

    International Nuclear Information System (INIS)

    Bark, R.A.; Sharpey-Schafer, J.F.; Maliage, S.M.; Madiba, T.E.; Komati, F.S.; Lawrie, E.A.; Lawrie, J.J.; Lindasy, R.; Maine, P.; Mullins, S.M.; Murray, S.H.T.; Ncapayi, N.J.; Ramashidza, T.M.; Smit, F.D.; Vymers, P.

    2010-01-01

    The low-lying, odd-spin negative parity bands in the mass 160 region have been identified as candidates for the rotation of a tetrahedral shape, as they have very weak in-band E2 transitions. We report the observation of such bands in 160 Yb and 154 Gd. They are crossed by 2 quasiparticle bands which allow band mixing calculations to be carried out to derive relative quadrupole moments. However, those studied are not consistent with zero, as required for tetrahedral shape. The aligned angular momenta of the bands suggest an octupole vibrational assignment.

  8. A tetrapyridine ligand with a rigid tetrahedral core forms metal-organic frameworks with PtS type architecture.

    Science.gov (United States)

    Caputo, Christopher B; Vukotic, V Nicholas; Sirizzotti, Natalie M; Loeb, Stephen J

    2011-08-14

    A new tetradentate, pyridine ligand with a rigid tetrahedral core can be prepared in good yield by a cross-coupling methodology. Two metal organic framework structures of Cu(II) with PtS-type topology having a carbon atom as the tetrahedral node have been characterized utilising this ligand. This journal is © The Royal Society of Chemistry 2011

  9. Direct Observation of Very Large Zero-Field Splitting in a Tetrahedral Ni(II)Se4 Coordination Complex.

    Science.gov (United States)

    Jiang, Shang-Da; Maganas, Dimitrios; Levesanos, Nikolaos; Ferentinos, Eleftherios; Haas, Sabrina; Thirunavukkuarasu, Komalavalli; Krzystek, J; Dressel, Martin; Bogani, Lapo; Neese, Frank; Kyritsis, Panayotis

    2015-10-14

    The high-spin (S = 1) tetrahedral Ni(II) complex [Ni{(i)Pr2P(Se)NP(Se)(i)Pr2}2] was investigated by magnetometry, spectroscopic, and quantum chemical methods. Angle-resolved magnetometry studies revealed the orientation of the magnetization principal axes. The very large zero-field splitting (zfs), D = 45.40(2) cm(-1), E = 1.91(2) cm(-1), of the complex was accurately determined by far-infrared magnetic spectroscopy, directly observing transitions between the spin sublevels of the triplet ground state. These are the largest zfs values ever determined--directly--for a high-spin Ni(II) complex. Ab initio calculations further probed the electronic structure of the system, elucidating the factors controlling the sign and magnitude of D. The latter is dominated by spin-orbit coupling contributions of the Ni ions, whereas the corresponding effects of the Se atoms are remarkably smaller.

  10. Environmentally stable adsorbent of tetrahedral silica and non-tetrahedral alumina for removal and recovery of malachite green dye from aqueous solution

    International Nuclear Information System (INIS)

    Kannan, Chellapandian; Sundaram, Thiravium; Palvannan, Thayumanavan

    2008-01-01

    The conventional adsorbents like activated carbon, agricultural wastes, molecular sieves, etc., used for dye adsorption are unstable in the environment for long time, and hence the adsorbed dyes again gets liberated and pollute the environment. To avoid this problem, environmentally stable adsorbent of silica and alumina should be employed for malachite green adsorption. The adsorbents were characterized by Fourier transformed infrared spectroscopy (FT-IR) to confirm the tetrahedral framework of silica and non-tetrahedral framework of alumina. The adsorption equilibrium of dye on alumina and silica were 4 and 5 h, respectively, this less adsorption time on alumina might be due to the less activation energy on alumina (63.46 kJ mol -1 ) than silica (69.93 kJ mol -1 ). Adsorption increased with increase of temperature on silica, in alumina, adsorption increased up to 60 deg. C, and further increase of temperature decreased the adsorption due to the structural change of non-tetrahedral alumina in water. The optimum pH for dye adsorption on alumina was 5 and silica was 6. The dye adsorptions on both adsorbents followed pseudo-second-order kinetics. The adsorption well matched with Langmuir and Freundlich adsorption isotherms and found that adsorption capacity on alumina was more than silica. The thermodynamic studies proved that the adsorption was endothermic and chemisorptions (ΔH o > 40 kJ mol -1 ) on alumina and silica. Recovery of dye on alumina and silica were studied from 30 to 90 deg. C and observed that 52% of dye was recovered from alumina and only 3.5% from silica. The less recovery on silica proved the strong adsorption of dye on silica than alumina

  11. Environmentally stable adsorbent of tetrahedral silica and non-tetrahedral alumina for removal and recovery of malachite green dye from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, Chellapandian [Department of Chemistry, Periyar University, Salem 636011, Tamilnadu (India)], E-mail: chellapandiankannan@gmail.com; Sundaram, Thiravium [Department of Chemistry, Periyar University, Salem 636011, Tamilnadu (India); Palvannan, Thayumanavan [Department of Biochemistry, Periyar University, Salem 636011, Tamilnadu (India)

    2008-08-30

    The conventional adsorbents like activated carbon, agricultural wastes, molecular sieves, etc., used for dye adsorption are unstable in the environment for long time, and hence the adsorbed dyes again gets liberated and pollute the environment. To avoid this problem, environmentally stable adsorbent of silica and alumina should be employed for malachite green adsorption. The adsorbents were characterized by Fourier transformed infrared spectroscopy (FT-IR) to confirm the tetrahedral framework of silica and non-tetrahedral framework of alumina. The adsorption equilibrium of dye on alumina and silica were 4 and 5 h, respectively, this less adsorption time on alumina might be due to the less activation energy on alumina (63.46 kJ mol{sup -1}) than silica (69.93 kJ mol{sup -1}). Adsorption increased with increase of temperature on silica, in alumina, adsorption increased up to 60 deg. C, and further increase of temperature decreased the adsorption due to the structural change of non-tetrahedral alumina in water. The optimum pH for dye adsorption on alumina was 5 and silica was 6. The dye adsorptions on both adsorbents followed pseudo-second-order kinetics. The adsorption well matched with Langmuir and Freundlich adsorption isotherms and found that adsorption capacity on alumina was more than silica. The thermodynamic studies proved that the adsorption was endothermic and chemisorptions ({delta}H{sup o} > 40 kJ mol{sup -1}) on alumina and silica. Recovery of dye on alumina and silica were studied from 30 to 90 deg. C and observed that 52% of dye was recovered from alumina and only 3.5% from silica. The less recovery on silica proved the strong adsorption of dye on silica than alumina.

  12. Atomic Scale Picture of the Ion Conduction Mechanism in Tetrahedral Network of Lanthanum Barium Gallate

    Energy Technology Data Exchange (ETDEWEB)

    Jalarvo, Niina H [ORNL; Gourdon, Olivier [ORNL; Bi, Zhonghe [ORNL; Gout, Delphine J [ORNL; Ohl, Michael E [ORNL; Paranthaman, Mariappan Parans [ORNL

    2013-01-01

    Combined experimental study of impedance spectroscopy, neutron powder diffraction and quasielastic neutron scattering was performed to shed light into the atomic scale ion migration processes in proton and oxide ion conductor; La0.8Ba1.2GaO3.9 . This material consist of tetrahedral GaO4 units, which are rather flexible and rocking motion of these units promotes the ionic migration process. The oxide ion (vacancy) conduction takes place on channels along c axis, involving a single elementary step, which occurs between adjacent tetrahedron (inter-tetrahedron jump). The proton conduction mechanism consists of intra-tetrahedron and inter-tetrahedron elementary processes. The intra-tetrahedron proton transport is the rate-limiting process, with activation energy of 0.44 eV. The rocking motion of the GaO4 tetrahedron aids the inter-tetrahedral proton transport, which has the activation energy of 0.068 eV.

  13. A tetrahedrally coordinated cobalt(II) aminophosphonate containing one-dimensional channels

    International Nuclear Information System (INIS)

    Gemmill, William R.; Smith, Mark D.; Reisner, Barbara A.

    2005-01-01

    A tetrahedrally coordinated cobalt(II) phosphonate, Co(O 3 PCH 2 CH 2 NH 2 ), has been synthesized using hydrothermal techniques. X-ray diffraction indicates that this material is a three-dimensional open framework with rings aligned along a single axis forming infinite one-dimensional channels. The framework decomposes just above 400 deg. C. Magnetic susceptibility data are consistent with weak antiferromagnetic ordering at low temperatures

  14. Urea-functionalized crystalline capsules for recognition and separation of tetrahedral oxoanions

    Energy Technology Data Exchange (ETDEWEB)

    Custelcean, Radu [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division

    2012-12-21

    We reviewed the persistent ability of tripodal TREN-based tris-urea receptors (TREN = tris(2-aminoethyl)amine) to self-assemble with a variety of oxoanions into dimeric capsules upon crystallization. The capsule crystallization allows for charge-, shape-, and size-selective encapsulation of tetrahedral XO4n-anions (n = 2,3), and provides an effective way to separate these anions from competitive aqueous environments.

  15. Electron transport determines the electrochemical properties of tetrahedral amorphous carbon (ta-C) thin films

    International Nuclear Information System (INIS)

    Palomäki, Tommi; Wester, Niklas; Caro, Miguel A.; Sainio, Sami; Protopopova, Vera; Koskinen, Jari; Laurila, Tomi

    2017-01-01

    Amorphous carbon based electrodes are very promising for electrochemical sensing applications. In order to better understand their structure-function relationship, the effect of film thickness on the electrochemical properties of tetrahedral amorphous carbon (ta-C) electrodes was investigated. ta-C thin films of 7, 15, 30, 50 and 100 nm were characterized in detail with Raman spectroscopy, transmission electron microscopy (TEM), conductive atomic force microscopy (c-AFM), scanning tunneling spectroscopy (STS) and X-ray absorption spectroscopy (XAS) to assess (i) the surface properties of the films, (ii) the effect of film thickness on their structure and electrical properties and (iii) the subsequent correlation with their electrochemistry. The electrochemical properties were investigated by cyclic voltammetry (CV) using two different outer-sphere redox probes, Ru(NH 3 ) 6 3+/2+ and FcMeOH, and by electrochemical impedance spectroscopy (EIS). Computational simulations using density functional theory (DFT) were carried out to rationalize the experimental findings. The characterization results showed that the sp 2 /sp 3 ratio increased with decreasing ta-C film thickness. This correlated with a decrease in mobility gap value and an increase in the average current through the films, which was also consistent with the computational results. XAS indicated that the surface of the ta-C films was always identical and composed of a sp 2 -rich layer. The CV measurements indicated reversible reaction kinetics for both outer-sphere redox probes at 7 and 15 nm ta-C films with a change to quasi-reversible behavior at a thickness of around 30 nm. The charge transfer resistance, obtained from EIS measurements, decreased with decreasing film thickness in accordance with the CV results. Based on the characterization and electrochemical results, we conclude that the reaction kinetics in the case of outer-sphere redox systems is determined mainly by the electron transport through the

  16. Broadband three-dimensional diamond-shaped invisible cloaks composed of tetrahedral homogeneous blocks

    International Nuclear Information System (INIS)

    Wang Xinhua; Qu Shaobo; Wu Xiang; Wang Jiafu; Ma Hua; Xu Zhuo

    2010-01-01

    By means of embedded optical transformation, three-dimensional diamond-shaped invisible cloaks composed of tetrahedral homogeneous blocks have been designed in this paper. The constitutive parameters of the invisible cloaks can be obtained based on the form invariance of Maxwell's equations in coordinate transformation. Numerical methods using the finite element method verified the diamond-shaped cloaks. The invisible properties of the designed cloaks are nearly perfect when the original line section is sufficiently short compared with its counterpart in the after-transformed space. The designed cloaks can operate in a wide bandwidth due to the line transformation in the coordinate transformation process.

  17. A three-dimensional tetrahedral-shaped conjugated small molecule for organic solar cells

    Directory of Open Access Journals (Sweden)

    QIN Yang

    2014-04-01

    Full Text Available We report the synthesis of a novel three-dimensional tetrahedral-shaped small molecule,SO,containing a tetraphenylsilane core and cyanoester functionalized terthiophene arms.A deep lying HOMO energy level of -5.3 eV and a narrow bandgap of 1.9 eV were obtained from cyclic voltammetry measurements.Absorption,X-ray scattering and differential scanning calorimetry experiments all indicate high crystallinity of this compound.Solar cells employing SO were fabricated and evaluated.The relatively low performance was mainly ascribed to lack of appreciable phase separation,which is confirmed by optical microscopy.

  18. H2O-induced trigonal-to-tetrahedral transition in boron zeolites

    International Nuclear Information System (INIS)

    Fois, E.; Gamba, A.; Trudu, F.; Tabacchi, G.

    2008-01-01

    The behaviour of a protonated boron-containing zeolite at intermediate hydration degree has been investigated by means of periodic DFT approaches. Results of a combined room-temperature Car-Parrinello molecular dynamics blue-moon path sampling simulation indicate that, in the line with experimental findings, the BO 3 /Si-OH acid site typical of dry samples is converted to a hydrated H 3 O + hydrogen bonded to tetrahedral BO 4 - at moderate water content (four H 2 O per B site) with an activation free barrier of the order of few k T.

  19. The application of Car-Parrinello molecular dynamics to the study of tetrahedral amorphous carbon

    International Nuclear Information System (INIS)

    McKenzie, D.R.; McCulloch, D.G.; Goringe, C.M.

    1998-01-01

    The Car-Parrinello method for carrying out molecular dynamics enables the forces between atoms to be calculated by solving Schroedinger's equation for the valence electrons using Density Functional Theory. The method is capable of giving good structural predictions for amorphous network solids by quenching from the melt, even in situations where the bonding changes from one site to another. In amorphous carbon where, depending on its environment, carbon may show sp 2 or sp 3 bonds. The method is applied here to the study of network solids using the example of tetrahedral amorphous carbon

  20. Soft Chemistry, Coloring and Polytypism in Filled Tetrahedral Semiconductors: Toward Enhanced Thermoelectric and Battery Materials.

    Science.gov (United States)

    White, Miles A; Medina-Gonzalez, Alan M; Vela, Javier

    2018-03-12

    Filled tetrahedral semiconductors are a rich family of compounds with tunable electronic structure, making them ideal for applications in thermoelectrics, photovoltaics, and battery anodes. Furthermore, these materials crystallize in a plethora of related structures that are very close in energy, giving rise to polytypism through the manipulation of synthetic parameters. This Minireview highlights recent advances in the solution-phase synthesis and nanostructuring of these materials. These methods enable the synthesis of metastable phases and polytypes that were previously unobtainable. Additionally, samples synthesized in solution phase have enhanced thermoelectric performance due to their decreased grain size. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Matrix elements of vibration kinetic energy operator of tetrahedral molecules in non-orthogonal-dependent coordinates

    Science.gov (United States)

    Protasevich, Alexander E.; Nikitin, Andrei V.

    2018-01-01

    In this work, we propose an algorithm for calculating the matrix elements of the kinetic energy operator for tetrahedral molecules. This algorithm uses the dependent six-angle coordinates (6A) and takes into account the full symmetry of molecules. Unlike A.V. Nikitin, M. Rey, and Vl. G. Tyuterev who operate with the kinetic energy operator only in Radau orthogonal coordinates, we consider a general case. The matrix elements are shown to be a sum of products of one-dimensional integrals.

  2. Tetrahedral ↔ octahedral network structure transition in simulated vitreous SiO2

    International Nuclear Information System (INIS)

    Vo Van Hoang; Nguyen Trung Hai; Hoang Zung

    2006-01-01

    By using molecular dynamics (MD) simulations we found a transition from a tetrahedral to an octahedral network structure in an amorphous SiO 2 model under compression from 2.20 to 5.35 g/cm 3 . And on heating of a high density amorphous (hda) model of 5.35 g/cm 3 at zero pressure, the structure transforms to a low density amorphous (lda) form. Simulations were done in a model containing 3000 particles under periodic boundary conditions with interatomic potentials which have a weak Coulomb interaction and a Morse type short-range interaction

  3. Highly parallel demagnetization field calculation using the fast multipole method on tetrahedral meshes with continuous sources

    Science.gov (United States)

    Palmesi, P.; Exl, L.; Bruckner, F.; Abert, C.; Suess, D.

    2017-11-01

    The long-range magnetic field is the most time-consuming part in micromagnetic simulations. Computational improvements can relieve problems related to this bottleneck. This work presents an efficient implementation of the Fast Multipole Method [FMM] for the magnetic scalar potential as used in micromagnetics. The novelty lies in extending FMM to linearly magnetized tetrahedral sources making it interesting also for other areas of computational physics. We treat the near field directly and in use (exact) numerical integration on the multipole expansion in the far field. This approach tackles important issues like the vectorial and continuous nature of the magnetic field. By using FMM the calculations scale linearly in time and memory.

  4. DNA-mediated self-assembly of tetrahedral plasmonic clusters for metafluids

    Science.gov (United States)

    Schade, Nicholas; Sun, Li; Lee, You-Jin; Fan, Jonathan; Capasso, Federico; Yi, Gi-Ra; Manoharan, Vinothan

    2014-03-01

    We direct the self-assembly of clusters of gold nanospheres with the goal of creating a bulk, isotropic, optical metafluid. We use spherical gold nanoparticles that are exceptionally smooth, monocrystalline, and monodisperse. These particles exhibit highly reproducible scattering spectra compared with commercially available gold colloids. We label them with DNA sequences and mix them together to self-assemble small clusters. By controlling the particle sizes and the interactions between them, we maximize the yield of tetrahedral clusters, the ideal structures for isotropic metamaterials.

  5. Tetrahedral-Mesh Simulation of Turbulent Flows with the Space-Time Conservative Schemes

    Science.gov (United States)

    Chang, Chau-Lyan; Venkatachari, Balaji; Cheng, Gary C.

    2015-01-01

    Direct numerical simulations of turbulent flows are predominantly carried out using structured, hexahedral meshes despite decades of development in unstructured mesh methods. Tetrahedral meshes offer ease of mesh generation around complex geometries and the potential of an orientation free grid that would provide un-biased small-scale dissipation and more accurate intermediate scale solutions. However, due to the lack of consistent multi-dimensional numerical formulations in conventional schemes for triangular and tetrahedral meshes at the cell interfaces, numerical issues exist when flow discontinuities or stagnation regions are present. The space-time conservative conservation element solution element (CESE) method - due to its Riemann-solver-free shock capturing capabilities, non-dissipative baseline schemes, and flux conservation in time as well as space - has the potential to more accurately simulate turbulent flows using unstructured tetrahedral meshes. To pave the way towards accurate simulation of shock/turbulent boundary-layer interaction, a series of wave and shock interaction benchmark problems that increase in complexity, are computed in this paper with triangular/tetrahedral meshes. Preliminary computations for the normal shock/turbulence interactions are carried out with a relatively coarse mesh, by direct numerical simulations standards, in order to assess other effects such as boundary conditions and the necessity of a buffer domain. The results indicate that qualitative agreement with previous studies can be obtained for flows where, strong shocks co-exist along with unsteady waves that display a broad range of scales, with a relatively compact computational domain and less stringent requirements for grid clustering near the shock. With the space-time conservation properties, stable solutions without any spurious wave reflections can be obtained without a need for buffer domains near the outflow/farfield boundaries. Computational results for the

  6. Tetrahedral 1B4Sb nanoclusters in GaP:(B, Sb)

    Energy Technology Data Exchange (ETDEWEB)

    Elyukhin, V A, E-mail: elyukhin@cinvestav.m [Departamento de Ingenieria Electrica-SEES, CINVESTAV-IPN, Avenida IPN 2508, Col. San Pedro Zacatenco, C. P. 07360, Mexico, D. F. (Mexico)

    2009-05-01

    Self-assembling conditions of 1B4Sb tetrahedral nanoclusters in GaP doped with boron and Sb isoelectronic impurities are represented in the ultradilute and dilute limits of the boron and Sb contents, respectively. The fulfilled estimates demonstrated the preferential complete or almost complete allocation of boron atoms in 1B4Sb nanoclusters at temperatures of 500 {sup 0}C and 900 {sup 0}C, respectively. The significant decrease of the sum of the free energies of the constituent compounds is the main origin of self-assembling. The reduction of the strain energy is the additional cause of this phenomenon.

  7. The Effect of Titanium Tetrahedral Coordination of Silica-Titania Catalyst on the Physical Properties of Biodiesel

    Science.gov (United States)

    Nizar, U. K.; Hidayatul, J.; Sundari, R.; Bahrizal, B.; Amran, A.; Putra, A.; Latisma DJ, L.; Dewata, I.

    2018-04-01

    This study investigates the correlation of the number of titanium tetrahedral coordination and biodiesel production. The solid-state method has been used to synthesis of silica-titania catalyst for biodiesel production, which the precursors, i.e. silica and titania commercials were heated in the temperature range of 450 - 550°C. The characterization of the prepared silica-titania has been studied by FTIR and DR UV-Vis in order to identify and calculate the presence of titanium tetrahedral coordination in silica-titania catalyst. A very small peak at around 950 cm-1 indicated the presence of titanium tetrahedral coordination through Si–O–Ti bonds. Deconvolution of DR UV-Vis spectra showed the coordination of titanium in silica-titania is more octahedral. However, the number of titanium tetrahedral coordination of the prepared silica-titania is found higher than that of TiO2 commercial. The increasing of titanium tetrahedral fraction in silica-titania affects the physical properties of biodiesel in terms of boiling point, viscosity and density, which is produced by the reaction of methanol and palm oil.

  8. Verification of the three-dimensional tetrahedral grid SN code THOR

    International Nuclear Information System (INIS)

    Schunert, S.; Ferrer, R.; Azmy, Y.

    2013-01-01

    In this work current capabilities implemented in the novel, arbitrary-order, tetrahedral-grid short characteristics S N radiation transport code THOR are verified based on four benchmark problems: (1) A one-group Method of Manufactured Solution (MMS) problem on a cuboidal domain, (2) an infinite medium eigenvalue problem with up-scattering, (3) a homogeneous torus and (4) a bare cube eigenvalue problem with anisotropic scattering up to order three. The first benchmark problem exercises the various spatial discretization options available in THOR: The short characteristics method in conjunction with polynomial expansions of the source and face fluxes either using the complete or Lagrange family of arbitrary orders. Using the numerical solution's order of convergence test in the framework of a mesh refinement study, correct implementation of a selection of spatial expansion orders is demonstrated for two meshes with tetrahedral aspect ratios close to unity and 50. The second benchmark problem exercises the implementation of angular fluxes on reflective boundary faces that are implicit within a mesh sweep, and up-scattering. The third benchmark problem comprises cyclic dependencies within the mesh sweep thus exercising the algorithm devised for 'breaking' the cyclic dependencies. Finally, the fourth benchmark problem, a simple bare cube, is used to test correct implementation of the anisotropic scattering capability. For all test problems THOR obtains solutions that converge to the reference/exact solution with the expected rate thereby contributing to our confidence in the correctness of its tested features in the present implementation. (authors)

  9. Spectroscopic criteria for identification of nuclear tetrahedral and octahedral symmetries: Illustration on a rare earth nucleus

    Science.gov (United States)

    Dudek, J.; Curien, D.; Dedes, I.; Mazurek, K.; Tagami, S.; Shimizu, Y. R.; Bhattacharjee, T.

    2018-02-01

    We formulate criteria for identification of the nuclear tetrahedral and octahedral symmetries and illustrate for the first time their possible realization in a rare earth nucleus 152Sm. We use realistic nuclear mean-field theory calculations with the phenomenological macroscopic-microscopic method, the Gogny-Hartree-Fock-Bogoliubov approach, and general point-group theory considerations to guide the experimental identification method as illustrated on published experimental data. Following group theory the examined symmetries imply the existence of exotic rotational bands on whose properties the spectroscopic identification criteria are based. These bands may contain simultaneously states of even and odd spins, of both parities and parity doublets at well-defined spins. In the exact-symmetry limit those bands involve no E 2 transitions. We show that coexistence of tetrahedral and octahedral deformations is essential when calculating the corresponding energy minima and surrounding barriers, and that it has a characteristic impact on the rotational bands. The symmetries in question imply the existence of long-lived shape isomers and, possibly, new waiting point nuclei—impacting the nucleosynthesis processes in astrophysics—and an existence of 16-fold degenerate particle-hole excitations. Specifically designed experiments which aim at strengthening the identification arguments are briefly discussed.

  10. Impact of local symmetry breaking on the physical properties of tetrahedral liquids.

    Science.gov (United States)

    Shi, Rui; Tanaka, Hajime

    2018-02-27

    Water and silica are the most important materials with local tetrahedral symmetry. They have similar crystalline polymorphs and exhibit anomalous density maximum in the liquid state. However, water and silica also show very different characteristics. For instance, the density of water varies much more sharply than that of liquid silica near the maximum as temperature changes. More notably, silica is a very good glass-former, but water is an extremely poor one. The physical origins of these similarities and differences still remain elusive, due to the lack of a microscopic understanding of the structural ordering in these two important liquids. Here, by accessing microscopic structural information by computer simulations, we reveal that local translational symmetry breaking is responsible for the density anomalies. On the other hand, the difference in the degree of local orientational symmetry breaking between water and silica, which originates from the difference in their bonding nature, causes not only the difference in the sharpness of density anomalies, but also their distinct glass-forming abilities. Our work not only shows the crucial roles of local translational and orientational symmetry breaking in the physical properties of the two extremely important materials, water and silica, but also provides a unified scenario applicable for other tetrahedral liquids such as Si, Ge, C, BeF 2 , and GeO 2 .

  11. Evolution of stacking fault tetrahedral and work hardening effect in copper single crystals

    Science.gov (United States)

    Liu, Hai Tao; Zhu, Xiu Fu; Sun, Ya Zhou; Xie, Wen Kun

    2017-11-01

    Stacking fault tetrahedral (SFT), generated in machining of copper single crystal as one type of subsurface defects, has significant influence on the performance of workpiece. In this study, molecular dynamics (MD) simulation is used to investigate the evolution of stacking fault tetrahedral in nano-cutting of copper single crystal. The result shows that SFT is nucleated at the intersection of differently oriented stacking fault (SF) planes and SFT evolves from the preform only containing incomplete surfaces into a solid defect. The evolution of SFT contains several stress fluctuations until the complete formation. Nano-indentation simulation is then employed on the machined workpiece from nano-cutting, through which the interaction between SFT and later-formed dislocations in subsurface is studied. In the meanwhile, force-depth curves obtained from nano-indentation on pristine and machined workpieces are compared to analyze the mechanical properties. By simulation of nano-cutting and nano-indentation, it is verified that SFT is a reason of the work hardening effect.

  12. Tetrahedral mesh generation of real terrain and topography effect on ERT image in Beishan region, Gansu province

    International Nuclear Information System (INIS)

    Lu Debao; Zhou Qiyou; Xiao Anlin; Song Zhen

    2014-01-01

    The paper starts from tetrahedral meshes generation of real terrain, a detailed way of tetradralization toward complicated terrain has been proposed based on comparing of advantage and disadvantage of several methods. DEM image has been used to help to generate tetrahedral mesh of research area. And then, forward soft Gmdata is used to calculate and analyze the topography effect on ERT Image with different kinds of terrain. Meanwhile, a quantitative way to define the topography effect was presented. Based on that, the method is used to eliminate the topography effect. The results show the method is effective and useful. (authors)

  13. Delaunay Tetrahedralization of the Heart Based on Integration of Open Source Codes

    International Nuclear Information System (INIS)

    Pavarino, E; Neves, L A; Machado, J M; Momente, J C; Zafalon, G F D; Pinto, A R; Valêncio, C R; Godoy, M F de; Shiyou, Y; Nascimento, M Z do

    2014-01-01

    The Finite Element Method (FEM) is a way of numerical solution applied in different areas, as simulations used in studies to improve cardiac ablation procedures. For this purpose, the meshes should have the same size and histological features of the focused structures. Some methods and tools used to generate tetrahedral meshes are limited mainly by the use conditions. In this paper, the integration of Open Source Softwares is presented as an alternative to solid modeling and automatic mesh generation. To demonstrate its efficiency, the cardiac structures were considered as a first application context: atriums, ventricles, valves, arteries and pericardium. The proposed method is feasible to obtain refined meshes in an acceptable time and with the required quality for simulations using FEM

  14. Amorphous-tetrahedral diamondlike carbon layered structures resulting from film growth energetics

    Science.gov (United States)

    Siegal, M. P.; Barbour, J. C.; Provencio, P. N.; Tallant, D. R.; Friedmann, T. A.

    1998-08-01

    High-resolution transmission electron microscopy (HRTEM) shows that amorphous-tetrahedral diamondlike carbon (a-tC) films grown by pulsed-laser deposition on Si(100) consist of three-to-four layers, depending on the growth energetics. We estimate the density of each layer using both HRTEM image contrast and Rutherford backscattering spectrometry. The first carbon layer and final surface layer have relatively low density. The bulk of the film between these two layers has higher density. For films grown under the most energetic conditions, there exists a superdense a-tC layer between the interface and bulk layers. The density of all four layers, and the thickness of the surface and interfacial layers, correlate well with the energetics of the depositing carbon species.

  15. Ultrafast carrier dynamics in tetrahedral amorphous carbon: carrier trapping versus electron-hole recombination

    International Nuclear Information System (INIS)

    Carpene, E; Mancini, E; Dallera, C; Schwen, D; Ronning, C; Silvestri, S De

    2007-01-01

    We report the investigation of the ultrafast carrier dynamics in thin tetrahedral amorphous carbon films by means of femtosecond time-resolved reflectivity. We estimated the electron-phonon relaxation time of a few hundred femtoseconds and we observed that under low optical excitation photo-generated carriers decay according to two distinct mechanisms attributed to trapping by defect states and direct electron-hole recombination. With high excitation, when photo-carrier and trap densities are comparable, a unique temporal evolution develops, as the time dependence of the trapping process becomes degenerate with the electron-hole recombination. This experimental evidence highlights the role of defects in the ultrafast electronic dynamics and is not specific to this particular form of carbon, but has general validity for amorphous and disordered semiconductors

  16. Self-assembly of a tetrahedral 58-nuclear barium vanadium oxide cluster.

    Science.gov (United States)

    Kastner, Katharina; Puscher, Bianka; Streb, Carsten

    2013-01-07

    We report the synthesis and characterization of a molecular barium vanadium oxide cluster featuring high nuclearity and high symmetry. The tetrameric, 2.3 nm cluster H(5)[Ba(10)(NMP)(14)(H(2)O)(8)[V(12)O(33)](4)Br] is based on a bromide-centred, octahedral barium scaffold which is capped by four previously unknown [V(12)O(33)](6-) clusters in a tetrahedral fashion. The compound represents the largest polyoxovanadate-based heterometallic cluster known to date. The cluster is formed in organic solution and it is suggested that the bulky N-methyl-2-pyrrolidone (NMP) solvent ligands allow the isolation of this giant molecule and prevent further condensation to a solid-state metal oxide. The cluster is fully characterized using single-crystal XRD, elemental analysis, ESI mass spectrometry and other spectroscopic techniques.

  17. Verification of the three-dimensional tetrahedral grid S{sub N} code THOR

    Energy Technology Data Exchange (ETDEWEB)

    Schunert, S. [Department of Nuclear Engineering, North Carolina State University (United States); Ferrer, R. [Studsvik Scandpower, Idaho Falls, ID (United States); Azmy, Y. [Department of Nuclear Engineering, North Carolina State University (United States)

    2013-07-01

    In this work current capabilities implemented in the novel, arbitrary-order, tetrahedral-grid short characteristics S{sub N} radiation transport code THOR are verified based on four benchmark problems: (1) A one-group Method of Manufactured Solution (MMS) problem on a cuboidal domain, (2) an infinite medium eigenvalue problem with up-scattering, (3) a homogeneous torus and (4) a bare cube eigenvalue problem with anisotropic scattering up to order three. The first benchmark problem exercises the various spatial discretization options available in THOR: The short characteristics method in conjunction with polynomial expansions of the source and face fluxes either using the complete or Lagrange family of arbitrary orders. Using the numerical solution's order of convergence test in the framework of a mesh refinement study, correct implementation of a selection of spatial expansion orders is demonstrated for two meshes with tetrahedral aspect ratios close to unity and 50. The second benchmark problem exercises the implementation of angular fluxes on reflective boundary faces that are implicit within a mesh sweep, and up-scattering. The third benchmark problem comprises cyclic dependencies within the mesh sweep thus exercising the algorithm devised for 'breaking' the cyclic dependencies. Finally, the fourth benchmark problem, a simple bare cube, is used to test correct implementation of the anisotropic scattering capability. For all test problems THOR obtains solutions that converge to the reference/exact solution with the expected rate thereby contributing to our confidence in the correctness of its tested features in the present implementation. (authors)

  18. Results and simulations on γ-spectroscopy of deformed nuclei: cases of isomers and tetrahedral nuclei

    International Nuclear Information System (INIS)

    Vancraeyenest, A.

    2010-10-01

    The major part of this work is about the realization and complete analysis of an experiment for studying isomeric states in 138,139,140 Nd nuclei. This was performed at Jyvaeskylae laboratory (Finland) using a fusion-evaporation reaction with 48 Ca beam on a thin 96 Zr target. Experimental setup consisted in the target position gamma ray detector Jurogam II which was coupled with the RITU recoil separator and the GREAT focal plane detector array. This particularly well adapted setup permit to manage γ spectroscopy of the interest nuclei around isomeric states. Indeed, we used prompt-delayed matrices to separate rays that come onto isomeric states and these who decay from them. Then, the correlations between the two components permit to establish feeding transitions of isomeric states. Thanks to this experiment, a new isomeric state was also highlighted in 139 Nd with spin 23/2+, which was predicted and interpreted in Cranked-Nilsson-Strutinsky calculation. Finally, very clean time spectra allow to determine precisely life-time of four states in four nuclei. This Ph.d. is also made of a part of the analysis of the first experimental search for fingerprints of tetrahedral symmetry in 156 Gd using high fold gamma ray spectroscopy. Thanks to a large number of triple coincidence events, we managed a detailed spectroscopy of this nucleus. Particularly, we found out 13 new transitions in positive parity bands. As a complement of this work, we have done GEANT4 simulations about the detection limits of low intensity transitions by Agata multidetector. Indeed, tetrahedral symmetry predicts vanishing of E2 transitions at lower spin states and simulations permit to determine observation limit of these transitions with different version of Agata. (author)

  19. Effect of high substrate bias and hydrogen and nitrogen incorporation on filtered cathodic vacuum arc deposited tetrahedral amorphous carbon films

    International Nuclear Information System (INIS)

    Panwar, O.S.; Khan, Mohd. Alim; Kumar, Mahesh; Shivaprasad, S.M.; Satyanarayana, B.S.; Dixit, P.N.; Bhattacharyya, R.; Khan, M.Y.

    2008-01-01

    The application of a sufficiently high negative substrate bias, during the growth of tetrahedral amorphous carbon (ta-C), is usually associated with low sp 3 bonding configuration and stressed films. However, in an effort to understand and utilize the higher pseudo thermo dynamical conditions during the film growth, at high negative substrate bias (- 300 V), reported here is a study on ta-C films grown under different hydrogen and nitrogen concentration. As grown ta-C films were studied under different negative substrate bias conditions. The variation of the sp 3 content and sp 3 /sp 2 ratio in the ta-C films exhibits a trend similar to those reported in literature, with a subtle variation in this report being the substrate bias voltage, which was observed to be around - 200 V, for obtaining the highest sp 3 (80%) bonding and sp 3 /sp 2 (3.95) ratio. The hydrogen and nitrogen incorporated ta-C films studied, at a bias of - 300 V, show an increase in sp 3 (87-91%) bonding and sp 3 /sp 2 (7-10) ratio in the range of studies reported. The inference is drawn on the basis of the set of data obtained from measurements carried out using X-ray photoelectron spectroscopy, X-ray induced Auger electron spectroscopy and Raman spectroscopy of as grown and hydrogen and nitrogen incorporated ta-C films deposited using an S bend filtered cathodic vacuum arc system. The study indicates the possibility of further tailoring ta-C film properties and also extending capabilities of the cathodic arc system for developing carbon based films for electronics and tribological applications

  20. Effect of high substrate bias and hydrogen and nitrogen incorporation on filtered cathodic vacuum arc deposited tetrahedral amorphous carbon films

    Energy Technology Data Exchange (ETDEWEB)

    Panwar, O.S. [Plasma Processed Materials Group, National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi-110 012 (India)], E-mail: ospanwar@mail.nplindia.ernet.in; Khan, Mohd. Alim [Plasma Processed Materials Group, National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi-110 012 (India); Kumar, Mahesh; Shivaprasad, S.M. [Surface Physics and Nanostructures Group, National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi-110 012 (India); Satyanarayana, B.S. [MIT Innovation Centre and Electronics and Communication Department, Manipal Institute of Technology, Manipal-579104 (India); Dixit, P.N. [Plasma Processed Materials Group, National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi-110 012 (India); Bhattacharyya, R. [Emeritus Scientist, National Physical Laboratory, New Delhi-110012 (India); Khan, M.Y. [Department of Physics, Jamia Millia Islamia, Central University, New Delhi-110025 (India)

    2008-02-29

    The application of a sufficiently high negative substrate bias, during the growth of tetrahedral amorphous carbon (ta-C), is usually associated with low sp{sup 3} bonding configuration and stressed films. However, in an effort to understand and utilize the higher pseudo thermo dynamical conditions during the film growth, at high negative substrate bias (- 300 V), reported here is a study on ta-C films grown under different hydrogen and nitrogen concentration. As grown ta-C films were studied under different negative substrate bias conditions. The variation of the sp{sup 3} content and sp{sup 3}/sp{sup 2} ratio in the ta-C films exhibits a trend similar to those reported in literature, with a subtle variation in this report being the substrate bias voltage, which was observed to be around - 200 V, for obtaining the highest sp{sup 3} (80%) bonding and sp{sup 3}/sp{sup 2} (3.95) ratio. The hydrogen and nitrogen incorporated ta-C films studied, at a bias of - 300 V, show an increase in sp{sup 3} (87-91%) bonding and sp{sup 3}/sp{sup 2} (7-10) ratio in the range of studies reported. The inference is drawn on the basis of the set of data obtained from measurements carried out using X-ray photoelectron spectroscopy, X-ray induced Auger electron spectroscopy and Raman spectroscopy of as grown and hydrogen and nitrogen incorporated ta-C films deposited using an S bend filtered cathodic vacuum arc system. The study indicates the possibility of further tailoring ta-C film properties and also extending capabilities of the cathodic arc system for developing carbon based films for electronics and tribological applications.

  1. The asc trinodal platform: Two-step assembly of triangular, tetrahedral, and trigonal-prismatic molecular building blocks

    KAUST Repository

    Schoedel, Alexander; Cairns, Amy; Belmabkhout, Youssef; Wojtas, Łukasz; Mohamed, Mona Hassan; Zhang, ZhenJie; Proserpio, Davide Maria; Eddaoudi, Mohamed; Zaworotko, Michael J.

    2013-01-01

    The self-assembly of triangular, tetrahedral, and trigonal-prismatic molecular building blocks affords the first example of a trinodal family of metal-organic materials. Four examples of isoreticular expanded and functionalized frameworks are detailed. Gas adsorption experiments validated the permanent porosity of the parent structure. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. The asc trinodal platform: Two-step assembly of triangular, tetrahedral, and trigonal-prismatic molecular building blocks

    KAUST Repository

    Schoedel, Alexander

    2013-02-10

    The self-assembly of triangular, tetrahedral, and trigonal-prismatic molecular building blocks affords the first example of a trinodal family of metal-organic materials. Four examples of isoreticular expanded and functionalized frameworks are detailed. Gas adsorption experiments validated the permanent porosity of the parent structure. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. 3-D minimum-structure inversion of magnetotelluric data using the finite-element method and tetrahedral grids

    Science.gov (United States)

    Jahandari, H.; Farquharson, C. G.

    2017-11-01

    Unstructured grids enable representing arbitrary structures more accurately and with fewer cells compared to regular structured grids. These grids also allow more efficient refinements compared to rectilinear meshes. In this study, tetrahedral grids are used for the inversion of magnetotelluric (MT) data, which allows for the direct inclusion of topography in the model, for constraining an inversion using a wireframe-based geological model and for local refinement at the observation stations. A minimum-structure method with an iterative model-space Gauss-Newton algorithm for optimization is used. An iterative solver is employed for solving the normal system of equations at each Gauss-Newton step and the sensitivity matrix-vector products that are required by this solver are calculated using pseudo-forward problems. This method alleviates the need to explicitly form the Hessian or Jacobian matrices which significantly reduces the required computation memory. Forward problems are formulated using an edge-based finite-element approach and a sparse direct solver is used for the solutions. This solver allows saving and re-using the factorization of matrices for similar pseudo-forward problems within a Gauss-Newton iteration which greatly minimizes the computation time. Two examples are presented to show the capability of the algorithm: the first example uses a benchmark model while the second example represents a realistic geological setting with topography and a sulphide deposit. The data that are inverted are the full-tensor impedance and the magnetic transfer function vector. The inversions sufficiently recovered the models and reproduced the data, which shows the effectiveness of unstructured grids for complex and realistic MT inversion scenarios. The first example is also used to demonstrate the computational efficiency of the presented model-space method by comparison with its data-space counterpart.

  4. Cause and Cure - Deterioration in Accuracy of CFD Simulations With Use of High-Aspect-Ratio Triangular Tetrahedral Grids

    Science.gov (United States)

    Chang, Sin-Chung; Chang, Chau-Lyan; Venkatachari, Balaji Shankar

    2017-01-01

    Traditionally high-aspect ratio triangular/tetrahedral meshes are avoided by CFD re-searchers in the vicinity of a solid wall, as it is known to reduce the accuracy of gradient computations in those regions and also cause numerical instability. Although for certain complex geometries, the use of high-aspect ratio triangular/tetrahedral elements in the vicinity of a solid wall can be replaced by quadrilateral/prismatic elements, ability to use triangular/tetrahedral elements in such regions without any degradation in accuracy can be beneficial from a mesh generation point of view. The benefits also carry over to numerical frameworks such as the space-time conservation element and solution element (CESE), where triangular/tetrahedral elements are the mandatory building blocks. With the requirement of the CESE method in mind, a rigorous mathematical framework that clearly identities the reason behind the difficulties in use of such high-aspect ratio triangular/tetrahedral elements is presented here. As will be shown, it turns out that the degree of accuracy deterioration of gradient computation involving a triangular element is hinged on the value of its shape factor Gamma def = sq sin Alpha1 + sq sin Alpha2 + sq sin Alpha3, where Alpha1; Alpha2 and Alpha3 are the internal angles of the element. In fact, it is shown that the degree of accuracy deterioration increases monotonically as the value of Gamma decreases monotonically from its maximal value 9/4 (attained by an equilateral triangle only) to a value much less than 1 (associated with a highly obtuse triangle). By taking advantage of the fact that a high-aspect ratio triangle is not necessarily highly obtuse, and in fact it can have a shape factor whose value is close to the maximal value 9/4, a potential solution to avoid accuracy deterioration of gradient computation associated with a high-aspect ratio triangular grid is given. Also a brief discussion on the extension of the current mathematical framework to the

  5. Molecular dinamics of tetrahedral clelate compounds of Cd(2) in solutions

    International Nuclear Information System (INIS)

    Nivorozhkin, L.E.; Minkin, V.I.; Borisenko, N.I.; Konstantinovskij, L.E.; Korobov, M.S.; Olekhnovich, R.Ya.

    1981-01-01

    Interconversion kinetics of enantiomers of tetrahedral intracomplex compounds of metals (ICM) on the base of unsymmetric ligands in solu-- tions is studied for several series of compounds according to the temperature dependence of the shape of line of prochiral substituents using the methods of the dynamic NMR (DNMR). The use of tetracoordinated ICM in the solutions of synthesized compounds of Cd(2) with the inclusion of magnetic isotope 111 Cd(S=1/2) to study molecular dynamics and the application of the corresponding methods of calculation of the DNMR signal forms permitted to clearly separate the mechanisms of digonal twist and degenerated ligand exchange. In ICM solutions the low-barrier transformations, connected with intramolecular digonal twist, take place as well as high-barrier processes of degenerated ligand exchange. The technique suggested can be applied to the studies of ICM molecular dynamics with other magnetic isotopes of metals ( 207 Pb, 199 Hg, etc.) and rapid non-degenerated ligand exchanges [ru

  6. Ion-Assisted Pulsed Laser Deposition of amorphous tetrahedral-coordinated carbon films

    Science.gov (United States)

    Friedmann, T. A.; Tallant, D. R.; Sullivan, J. P.; Siegal, M. P.; Simpson, R. L.

    1994-04-01

    A parametric study has been performed of amorphous tetrahedral carbon (a-tC) films produced by ion-assisted pulsed laser deposition (IAPLD). The ion voltage, current density, and feed gas composition (nitrogen in argon) have been varied. The resultant films were characterized by thickness, residual stress, Raman spectroscopy, and electrical resistivity. The Raman spectra have been fit to two gaussian peaks, the so called graphitic (G) peak and the disorder (D) peak. It has been found that the magnitude of the D peak and the residual compressive stress are inversely correlated. At low beam voltages and currents, the magnitude of the D peak is low, increasing as the ion beam voltage and current are raised. The ion beam voltage has the most dramatic effect on the magnitude of the D peak. At low voltages (200-500 V) the magnitude of the D peak is greater for ion beams with high percentages of nitrogen possibly indicative of C-N bonding in the films. At higher voltages (500-1500 V) the D peak intensity is less sensitive to the nitrogen content of the beam.

  7. Tetrahedral node for Transmission-Line Modeling (TLM) applied to Bio-heat Transfer.

    Science.gov (United States)

    Milan, Hugo F M; Gebremedhin, Kifle G

    2016-12-01

    Transmission-Line Modeling (TLM) is a numerical method used to solve complex and time-domain bio-heat transfer problems. In TLM, parallelepipeds are used to discretize three-dimensional problems. The drawback in using parallelepiped shapes is that instead of refining only the domain of interest, a large additional domain would also have to be refined, which results in increased computational time and memory space. In this paper, we developed a tetrahedral node for TLM applied to bio-heat transfer that does not have the drawback associated with the parallelepiped node. The model includes heat source, blood perfusion, boundary conditions and initial conditions. The boundary conditions could be adiabatic, temperature, heat flux, or convection. The predicted temperature and heat flux were compared against results from an analytical solution and the results agreed within 2% for a mesh size of 69,941 nodes and a time step of 5ms. The method was further validated against published results of maximum skin-surface temperature difference in a breast with and without tumor and the results agreed within 6%. The published results were obtained from a model that used parallelepiped TLM node. An open source software, TLMBHT, was written using the theory developed herein and is available for download free-of-charge. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Ordering principles for tetrahedral chains in Ga- and Co-substituted YBCO intergrowths

    International Nuclear Information System (INIS)

    Milat, O.; Krekels, T.; Tendeloo, G. van; Amelinckx, S.

    1993-01-01

    A model for superstructure ordering in the ''chain'' layers of Ga (Co) substituted YBCO intergrowths with general formula (REO 2 ) N Sr 2 MCu 2 O 5 (M Co, Ga; n = 1, 2, ..) is proposed. By Ga or Co substitution for Cu, the structure of the ''chain'' layer changes: instead of the CuO 4 planar squares, the chains consist of MO 4 tetrahedra (M = Ga, Co) running along the [110] perovskite direction. The existing model for the Ga substituted ''123'' implies that all the chains are the same. Our new model is based on the results of Electron diffraction and High-resolution electron microscopy investigations. The model reveals the occurene of two types of chains as a consequence of ''opposite'' ordering between neighbouring tetrahedra. The corner linked tetrahedra in each chain appear as alternatingly rotated in opposite sense, and a chain itself, as being displaced with respect to the underlying structure in one of two senses; either forth (right) or back (left) along the chain direction. The regular alternation of chains of opposite type doubles the periodicity within a layer and induces the possibility for intrinsic disorder in the chain layer stacking sequence. The planar superstructure and a staggered stacking of the tetrahedral chain layers is found irrespective of the rest of the intergrowth structure. Superstructure ordering in the case of Co substitution is more perfect than for the Ga substitution. (orig.)

  9. A Rac1--GDP trimer complex binds zinc with tetrahedral and octahedral coordination, displacing magnesium

    Energy Technology Data Exchange (ETDEWEB)

    Prehna, G.; Stebbins, C

    2007-01-01

    The Rho family of small GTPases represent well characterized signaling molecules that regulate many cellular functions such as actin cytoskeletal arrangement and the cell cycle by acting as molecular switches. A Rac1-GDP-Zn complex has been crystallized in space group P3221 and its crystal structure has been solved at 1.9 {angstrom} resolution. These trigonal crystals reveal the unexpected ability of Rac1 to coordinate Zn atoms in a tetrahedral fashion by use of its biologically relevant switch I and switch II regions. Upon coordination of zinc, the switch I region is stabilized in the GDP-bound conformation and contributes to a Rac1 trimer in the asymmetric unit. Zinc coordination causes switch II to adopt a novel conformation with a symmetry-related molecule. Additionally, zinc was found to displace magnesium from its octahedral coordination at switch I, although GDP binding remained stable. This structure represents the first reported Rac1-GDP-Zn complex, which further underscores the conformational flexibility and versatility of the small GTPase switch regions.

  10. A Rac1-GDP Trimer Complex Binds Zinc with Tetrahedral and Octahedral Coordination, Displacing Magnesium

    Energy Technology Data Exchange (ETDEWEB)

    Prehna,G.; Stebbins, E.

    2007-01-01

    The Rho family of small GTPases represent well characterized signaling molecules that regulate many cellular functions such as actin cytoskeletal arrangement and the cell cycle by acting as molecular switches. A Rac1-GDP-Zn complex has been crystallized in space group P3{sub 2}21 and its crystal structure has been solved at 1.9 {angstrom} resolution. These trigonal crystals reveal the unexpected ability of Rac1 to coordinate Zn atoms in a tetrahedral fashion by use of its biologically relevant switch I and switch II regions. Upon coordination of zinc, the switch I region is stabilized in the GDP-bound conformation and contributes to a Rac1 trimer in the asymmetric unit. Zinc coordination causes switch II to adopt a novel conformation with a symmetry-related molecule. Additionally, zinc was found to displace magnesium from its octahedral coordination at switch I, although GDP binding remained stable. This structure represents the first reported Rac1-GDP-Zn complex, which further underscores the conformational flexibility and versatility of the small GTPase switch regions.

  11. Correlation between substrate bias, growth process and structural properties of phosphorus incorporated tetrahedral amorphous carbon films

    International Nuclear Information System (INIS)

    Liu Aiping; Zhu Jiaqi; Han Jiecai; Wu Huaping; Jia Zechun

    2007-01-01

    We investigate the growth process and structural properties of phosphorus incorporated tetrahedral amorphous carbon (ta-C:P) films which are deposited at different substrate biases by filtered cathodic vacuum arc technique with PH 3 as the dopant source. The films are characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy, Raman spectroscopy, residual stress measurement, UV/VIS/NIR absorption spectroscopy and temperature-dependent conductivity measurement. The atomic fraction of phosphorus in the films as a function of substrate bias is obtained by XPS analysis. The optimum bias for phosphorus incorporation is about -80 V. Raman spectra show that the amorphous structures of all samples with atomic-scaled smooth surface are not remarkably changed when PH 3 is implanted, but some small graphitic crystallites are formed. Moreover, phosphorus impurities and higher-energetic impinging ions are favorable for the clustering of sp 2 sites dispersed in sp 3 skeleton and increase the level of structural ordering for ta-C:P films, which further releases the compressive stress and enhances the conductivity of the films. Our analysis establishes an interrelationship between microstructure, stress state, electrical properties, and substrate bias, which helps to understand the deposition mechanism of ta-C:P films

  12. Erasing no-man's land by thermodynamically stabilizing the liquid-liquid transition in tetrahedral particles.

    Science.gov (United States)

    Smallenburg, Frank; Filion, Laura; Sciortino, Francesco

    2014-09-01

    One of the most controversial hypotheses for explaining the origin of the thermodynamic anomalies characterizing liquid water postulates the presence of a metastable second-order liquid-liquid critical point [1] located in the "no-man's land" [2]. In this scenario, two liquids with distinct local structure emerge near the critical temperature. Unfortunately, since spontaneous crystallization is rapid in this region, experimental support for this hypothesis relies on significant extrapolations, either from the metastable liquid or from amorphous solid water [3, 4]. Although the liquid-liquid transition is expected to feature in many tetrahedrally coordinated liquids, including silicon [5], carbon [6] and silica, even numerical studies of atomic and molecular models have been unable to conclusively prove the existence of this transition. Here we provide such evidence for a model in which it is possible to continuously tune the softness of the interparticle interaction and the flexibility of the bonds, the key ingredients controlling the existence of the critical point. We show that conditions exist where the full coexistence is thermodynamically stable with respect to crystallization. Our work offers a basis for designing colloidal analogues of water exhibiting liquid-liquid transitions in equilibrium, opening the way for experimental confirmation of the original hypothesis.

  13. Growth Mechanism and Origin of High s p3 Content in Tetrahedral Amorphous Carbon

    Science.gov (United States)

    Caro, Miguel A.; Deringer, Volker L.; Koskinen, Jari; Laurila, Tomi; Csányi, Gábor

    2018-04-01

    We study the deposition of tetrahedral amorphous carbon (ta-C) films from molecular dynamics simulations based on a machine-learned interatomic potential trained from density-functional theory data. For the first time, the high s p3 fractions in excess of 85% observed experimentally are reproduced by means of computational simulation, and the deposition energy dependence of the film's characteristics is also accurately described. High confidence in the potential and direct access to the atomic interactions allow us to infer the microscopic growth mechanism in this material. While the widespread view is that ta-C grows by "subplantation," we show that the so-called "peening" model is actually the dominant mechanism responsible for the high s p3 content. We show that pressure waves lead to bond rearrangement away from the impact site of the incident ion, and high s p3 fractions arise from a delicate balance of transitions between three- and fourfold coordinated carbon atoms. These results open the door for a microscopic understanding of carbon nanostructure formation with an unprecedented level of predictive power.

  14. Insights into Substrate Specificity and Metal Activation of Mammalian Tetrahedral Aspartyl Aminopeptidase

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yuanyuan; Farquhar, Erik R.; Chance, Mark R.; Palczewski, Krzysztof; Kiser, Philip D. (Case Western)

    2012-07-11

    Aminopeptidases are key enzymes involved in the regulation of signaling peptide activity. Here, we present a detailed biochemical and structural analysis of an evolutionary highly conserved aspartyl aminopeptidase called DNPEP. We show that this peptidase can cleave multiple physiologically relevant substrates, including angiotensins, and thus may play a key role in regulating neuron function. Using a combination of x-ray crystallography, x-ray absorption spectroscopy, and single particle electron microscopy analysis, we provide the first detailed structural analysis of DNPEP. We show that this enzyme possesses a binuclear zinc-active site in which one of the zinc ions is readily exchangeable with other divalent cations such as manganese, which strongly stimulates the enzymatic activity of the protein. The plasticity of this metal-binding site suggests a mechanism for regulation of DNPEP activity. We also demonstrate that DNPEP assembles into a functionally relevant tetrahedral complex that restricts access of peptide substrates to the active site. These structural data allow rationalization of the enzyme's preference for short peptide substrates with N-terminal acidic residues. This study provides a structural basis for understanding the physiology and bioinorganic chemistry of DNPEP and other M18 family aminopeptidases.

  15. Tetrahedral silsesquioxane-C2H2Ti complex for hydrogen storage

    Science.gov (United States)

    Konda, Ravinder; Tavhare, Priyanka; Ingale, Nilesh; Chaudhari, Ajay

    2018-04-01

    The interaction of molecular hydrogen with tetrahedral silsesquioxane (T4)-C2H2Ti complex has been studied using Density Functional Theory with M06-2X functional and MP2 method with 6-311++G** basis set. T4-C2H2Ti complex can absorb maximum five hydrogen molecules with the gravimetric hydrogen storage capacity of 3.4 wt %. Adsorption energy calculations show that H2 adsorption on T4-C2H2Ti complex is favorable at room temperature by both the methods. We have studied the effect of temperature and pressure on Gibbs free energy corrected adsorption energies. Molecular dynamics simulations for H2 adsorbed T4-C2H2Ti complex have also been performed at 300K and show that loosely bonded H2 molecule flies away within 1fs. Various interaction energies within the complex are studied. Stability of a complex is predicted by means of a gap between Highest Occupied Molecular Orbital (HUMO) and Lowest Unoccupied Molecular Orbital (LUMO). The H2 desorption temperature for T4-C2H2Ti complex is calculated with Van't Hoff equation and it is found to be 229K.

  16. Split-Cell Exponential Characteristic Transport Method for Unstructured Tetrahedral Meshes

    International Nuclear Information System (INIS)

    Brennan, Charles R.; Miller, Rodney L.; Mathews, Kirk A.

    2001-01-01

    The nonlinear, exponential characteristic (EC) method is extended to unstructured meshes of tetrahedral cells in three-dimensional Cartesian coordinates. The split-cell approach developed for the linear characteristic (LC) method on such meshes is used. Exponential distributions of the source within a cell and of the inflow flux on upstream faces of the cell are assumed. The coefficients of these distributions are determined by nonlinear root solving so as to match the zeroth and first moments of the source or entering flux. Good conditioning is achieved by casting the formulas for the moments of the source, inflow flux, and solution flux as sums of positive functions and by using accurate and robust algorithms for evaluation of those functions. Various test problems are used to compare the performance of the EC and LC methods. The EC method is somewhat less accurate than the LC method in regions of net out leakage but is strictly positive and retains good accuracy with optically thick cells, as in shielding problems, unlike the LC method. The computational cost per cell is greater for the EC method, but the use of substantially coarser meshes can make the EC method less expensive in total cost. The EC method, unlike the LC method, may fail if negative cross sections or angular quadrature weights are used. It is concluded that the EC and LC methods should be practical, reliable, and complimentary schemes for these meshes

  17. Simultaneous travel time tomography for updating both velocity and reflector geometry in triangular/tetrahedral cell model

    Science.gov (United States)

    Bai, Chao-ying; He, Lei-yu; Li, Xing-wang; Sun, Jia-yu

    2018-05-01

    To conduct forward and simultaneous inversion in a complex geological model, including an irregular topography (or irregular reflector or velocity anomaly), we in this paper combined our previous multiphase arrival tracking method (referred as triangular shortest-path method, TSPM) in triangular (2D) or tetrahedral (3D) cell model and a linearized inversion solver (referred to as damped minimum norms and constrained least squares problem solved using the conjugate gradient method, DMNCLS-CG) to formulate a simultaneous travel time inversion method for updating both velocity and reflector geometry by using multiphase arrival times. In the triangular/tetrahedral cells, we deduced the partial derivative of velocity variation with respective to the depth change of reflector. The numerical simulation results show that the computational accuracy can be tuned to a high precision in forward modeling and the irregular velocity anomaly and reflector geometry can be accurately captured in the simultaneous inversion, because the triangular/tetrahedral cell can be easily used to stitch the irregular topography or subsurface interface.

  18. Simple shearing flow of dry soap foams with tetrahedrally close-packed structure

    Energy Technology Data Exchange (ETDEWEB)

    Reinelt, Douglas A. [Department of Mathematics, Southern Methodist University, Dallas, Texas 75275-0156 (United States); Kraynik, Andrew M. [Engineering Sciences Center, Sandia National Laboratories, Albuquerque, New Mexico 87185-0834 (United States)

    2000-05-01

    The microrheology of dry soap foams subjected to quasistatic, simple shearing flow is analyzed. Two different monodisperse foams with tetrahedrally close-packed (TCP) structure are examined: Weaire-Phelan (A15) and Friauf-Laves (C15). The elastic-plastic response is evaluated by using the Surface Evolver to calculate foam structures that minimize total surface area at each value of strain. The foam geometry and macroscopic stress are piecewise continuous functions of strain. The stress scales as T/V{sup 1/3}, where T is surface tension and V is cell volume. Each discontinuity corresponds to large changes in foam geometry and topology that restore equilibrium to unstable configurations that violate Plateau's laws. The instabilities occur when the length of an edge on a polyhedral foam cell vanishes. The length can tend to zero smoothly or abruptly with strain. The abrupt case occurs when a small increase in strain changes the energy profile in the neighborhood of a foam structure from a local minimum to a saddle point, which can lead to symmetry-breaking bifurcations. In general, the new structure associated with each stable solution branch results from an avalanche of local topology changes called T1 transitions. Each T1 cascade produces different cell neighbors, reduces surface energy, and provides an irreversible, film-level mechanism for plastic yield behavior. Stress-strain curves and average stresses are evaluated by examining foam orientations that admit strain-periodic behavior. For some orientations, the deformation cycle includes Kelvin cells instead of the original TCP structure; but the foam does not remain perfectly ordered. Bifurcations during subsequent T1 cascades lead to disorder and can even cause strain localization. (c) 2000 Society of Rheology.

  19. The use of tetrahedral mesh geometries in Monte Carlo simulation of applicator based brachytherapy dose distributions

    International Nuclear Information System (INIS)

    Fonseca, Gabriel Paiva; Yoriyaz, Hélio; Landry, Guillaume; White, Shane; Reniers, Brigitte; Verhaegen, Frank; D’Amours, Michel; Beaulieu, Luc

    2014-01-01

    Accounting for brachytherapy applicator attenuation is part of the recommendations from the recent report of AAPM Task Group 186. To do so, model based dose calculation algorithms require accurate modelling of the applicator geometry. This can be non-trivial in the case of irregularly shaped applicators such as the Fletcher Williamson gynaecological applicator or balloon applicators with possibly irregular shapes employed in accelerated partial breast irradiation (APBI) performed using electronic brachytherapy sources (EBS). While many of these applicators can be modelled using constructive solid geometry (CSG), the latter may be difficult and time-consuming. Alternatively, these complex geometries can be modelled using tessellated geometries such as tetrahedral meshes (mesh geometries (MG)). Recent versions of Monte Carlo (MC) codes Geant4 and MCNP6 allow for the use of MG. The goal of this work was to model a series of applicators relevant to brachytherapy using MG. Applicators designed for 192 Ir sources and 50 kV EBS were studied; a shielded vaginal applicator, a shielded Fletcher Williamson applicator and an APBI balloon applicator. All applicators were modelled in Geant4 and MCNP6 using MG and CSG for dose calculations. CSG derived dose distributions were considered as reference and used to validate MG models by comparing dose distribution ratios. In general agreement within 1% for the dose calculations was observed for all applicators between MG and CSG and between codes when considering volumes inside the 25% isodose surface. When compared to CSG, MG required longer computation times by a factor of at least 2 for MC simulations using the same code. MCNP6 calculation times were more than ten times shorter than Geant4 in some cases. In conclusion we presented methods allowing for high fidelity modelling with results equivalent to CSG. To the best of our knowledge MG offers the most accurate representation of an irregular APBI balloon applicator. (paper)

  20. Nanodiamonds on tetrahedral amorphous carbon significantly enhance dopamine detection and cell viability.

    Science.gov (United States)

    Peltola, Emilia; Wester, Niklas; Holt, Katherine B; Johansson, Leena-Sisko; Koskinen, Jari; Myllymäki, Vesa; Laurila, Tomi

    2017-02-15

    We hypothesize that by using integrated carbon nanostructures on tetrahedral amorphous carbon (ta-C), it is possible to take the performance and characteristics of these bioelectrodes to a completely new level. The integrated carbon electrodes were realized by combining nanodiamonds (NDs) with ta-C thin films coated on Ti-coated Si-substrates. NDs were functionalized with mixture of carboxyl and amine groups ND andante or amine ND amine , carboxyl ND vox or hydroxyl groups ND H and drop-casted or spray-coated onto substrate. By utilizing these novel structures we show that (i) the detection limit for dopamine can be improved by two orders of magnitude [from 10µM to 50nM] in comparison to ta-C thin film electrodes and (ii) the coating method significantly affects electrochemical properties of NDs and (iii) the ND coatings selectively promote cell viability. ND andante and ND H showed most promising electrochemical properties. The viability of human mesenchymal stem cells and osteoblastic SaOS-2 cells was increased on all ND surfaces, whereas the viability of mouse neural stem cells and rat neuroblastic cells was improved on ND andante and ND H and reduced on ND amine and ND vox. The viability of C6 cells remained unchanged, indicating that these surfaces will not cause excess gliosis. In summary, we demonstrated here that by using functionalized NDs on ta-C thin films we can significantly improve sensitivity towards dopamine as well as selectively promote cell viability. Thus, these novel carbon nanostructures provide an interesting concept for development of various in vivo targeted sensor solutions. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. LiBSi2: a tetrahedral semiconductor framework from boron and silicon atoms bearing lithium atoms in the channels.

    Science.gov (United States)

    Zeilinger, Michael; van Wüllen, Leo; Benson, Daryn; Kranak, Verina F; Konar, Sumit; Fässler, Thomas F; Häussermann, Ulrich

    2013-06-03

    Silicon swallows up boron: The novel open tetrahedral framework structure (OTF) of the Zintl phase LiBSi2 was made by applying high pressure to a mixture of LiB and elemental silicon. The compound represents a new topology in the B-Si net (called tum), which hosts Li atoms in the channels (see picture). LiBSi2 is the first example where B and Si atoms form an ordered common framework structure with B engaged exclusively in heteronuclear B-Si contacts.

  2. LiBSi{sub 2}: a tetrahedral semiconductor framework from boron and silicon atoms bearing lithium atoms in the channels

    Energy Technology Data Exchange (ETDEWEB)

    Zeilinger, Michael; Faessler, Thomas F. [Department of Chemistry, Technische Universitaet Muenchen, Garching (Germany); Wuellen, Leo van [Department of Physics, University of Augsburg (Germany); Benson, Daryn [Department of Physics, Arizona State University, Tempe, AZ (United States); Kranak, Verina F.; Konar, Sumit; Haeussermann, Ulrich [Department of Materials and Environmental Chemistry, Stockholm University (Sweden)

    2013-06-03

    Silicon swallows up boron. The novel open tetrahedral framework structure (OTF) of the Zintl phase LiBSi{sub 2} was made by applying high pressure to a mixture of LiB and elemental silicon. The compound represents a new topology in the B-Si net (called tum), which hosts Li atoms in the channels. LiBSi{sub 2} is the first example where B and Si atoms form an ordered common framework structure with B engaged exclusively in heteronuclear B-Si contacts. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. The Case for Tetrahedral Oxy-subhydride (TOSH Structures in the Exclusion Zones of Anchored Polar Solvents Including Water

    Directory of Open Access Journals (Sweden)

    Klaus Oehr

    2014-11-01

    Full Text Available We hypothesize a mechanistic model of how negatively-charged exclusion zones (EZs are created. While the growth of EZs is known to be associated with the absorption of ambient photonic energy, the molecular dynamics giving rise to this process need greater elucidation. We believe they arise due to the formation of oxy-subhydride structures (OH−(H2O4 with a tetrahedral (sp3 (OH−(H2O3 core. Five experimental data sets derived by previous researchers were assessed in this regard: (1 water-derived EZ light absorbance at specific infrared wavelengths, (2 EZ negative potential in water and ethanol, (3 maximum EZ light absorbance at 270 nm ultraviolet wavelength, (4 ability of dimethyl sulphoxide but not ether to form an EZ, and (5 transitory nature of melting ice derived EZs. The proposed tetrahedral oxy-subhydride structures (TOSH appear to adequately account for all of the experimental evidence derived from water or other polar solvents.

  4. Detailed intermolecular structure of molecular liquids containing slightly distorted tetrahedral molecules with C(3v) symmetry: chloroform, bromoform, and methyl-iodide.

    Science.gov (United States)

    Pothoczki, Szilvia; Temleitner, László; Pusztai, László

    2011-01-28

    Analyses of the intermolecular structure of molecular liquids containing slightly distorted tetrahedral molecules of the CXY(3)-type are described. The process is composed of the determination of several different distance-dependent orientational correlation functions, including ones that are introduced here. As a result, a complete structure classification could be provided for CXY(3) molecular liquids, namely for liquid chloroform, bromoform, and methyl-iodide. In the present work, the calculations have been conducted on particle configurations resulting from reverse Monte Carlo computer modeling: these particle arrangements have the advantage that they are fully consistent with structure factors from neutron and x-ray diffraction measurements. It has been established that as the separation between neighboring molecules increases, the dominant mutual orientations change from face-to-face to edge-to-edge, via the edge-to-face arrangements. Depending on the actual liquid, these geometrical elements (edges and faces of the distorted tetrahedra) were found to contain different atoms. From the set of liquids studied here, the structure of methyl-iodide was found to be easiest to describe on the basis of pure steric effects (molecular shape, size, and density) and the structure of liquid chloroform seems to be the furthest away from the corresponding "flexible fused hard spheres" like reference system.

  5. Calculation of energetic characteristics of 3d-transition metal ion aquacomplexes in tetrahedral and octahedral coordination by broadened Hukkel method

    International Nuclear Information System (INIS)

    Zhogolev, D.A.; Bunyatyan, B.Kh.; Yatsimirskij, K.B.

    1975-01-01

    Aquacomplexes formation energies of bi- and trivalent ions of 3d transition metals from Sc to Ni in the tetrahedral and octahedral coordinations have been calculated to compare their energetic advantages. Unlike ions of alkali metals and halogens, a tendency for higher or at least equal energetic effect of the formation of a tetrahedral complex, compared to octahedral, is characteristic of the ions under study. This can be explained by an increase in the covalency degree of the bond ion-ligand and by a considerable charge transfer from ligands to the central ion in the case of transition elements

  6. Mo-containing tetrahedral amorphous carbon deposited by dual filtered cathodic vacuum arc with selective pulsed bias voltage

    International Nuclear Information System (INIS)

    Pasaja, Nitisak; Sansongsiri, Sakon; Intarasiri, Saweat; Vilaithong, Thiraphat; Anders, Andre

    2007-01-01

    Metal-containing tetrahedral amorphous carbon films were produced by dual filtered cathodic vacuum arc plasma sources operated in sequentially pulsed mode. Negatively pulsed bias was applied to the substrate when carbon plasma was generated, whereas it was absent when the molybdenum plasma was presented. Film thickness was measured after deposition by profilometry. Glass slides with silver pads were used as substrates for the measurement of the sheet resistance. The microstructure and composition of the films were characterized by Raman spectroscopy and Rutherford backscattering, respectively. It was found that the electrical resistivity decreases with an increase of the Mo content, which can be ascribed to an increase of the sp 2 content and an increase of the sp 2 cluster size

  7. The Space-Time Conservative Schemes for Large-Scale, Time-Accurate Flow Simulations with Tetrahedral Meshes

    Science.gov (United States)

    Venkatachari, Balaji Shankar; Streett, Craig L.; Chang, Chau-Lyan; Friedlander, David J.; Wang, Xiao-Yen; Chang, Sin-Chung

    2016-01-01

    Despite decades of development of unstructured mesh methods, high-fidelity time-accurate simulations are still predominantly carried out on structured, or unstructured hexahedral meshes by using high-order finite-difference, weighted essentially non-oscillatory (WENO), or hybrid schemes formed by their combinations. In this work, the space-time conservation element solution element (CESE) method is used to simulate several flow problems including supersonic jet/shock interaction and its impact on launch vehicle acoustics, and direct numerical simulations of turbulent flows using tetrahedral meshes. This paper provides a status report for the continuing development of the space-time conservation element solution element (CESE) numerical and software framework under the Revolutionary Computational Aerosciences (RCA) project. Solution accuracy and large-scale parallel performance of the numerical framework is assessed with the goal of providing a viable paradigm for future high-fidelity flow physics simulations.

  8. A parallel electrostatic Particle-in-Cell method on unstructured tetrahedral grids for large-scale bounded collisionless plasma simulations

    Science.gov (United States)

    Averkin, Sergey N.; Gatsonis, Nikolaos A.

    2018-06-01

    An unstructured electrostatic Particle-In-Cell (EUPIC) method is developed on arbitrary tetrahedral grids for simulation of plasmas bounded by arbitrary geometries. The electric potential in EUPIC is obtained on cell vertices from a finite volume Multi-Point Flux Approximation of Gauss' law using the indirect dual cell with Dirichlet, Neumann and external circuit boundary conditions. The resulting matrix equation for the nodal potential is solved with a restarted generalized minimal residual method (GMRES) and an ILU(0) preconditioner algorithm, parallelized using a combination of node coloring and level scheduling approaches. The electric field on vertices is obtained using the gradient theorem applied to the indirect dual cell. The algorithms for injection, particle loading, particle motion, and particle tracking are parallelized for unstructured tetrahedral grids. The algorithms for the potential solver, electric field evaluation, loading, scatter-gather algorithms are verified using analytic solutions for test cases subject to Laplace and Poisson equations. Grid sensitivity analysis examines the L2 and L∞ norms of the relative error in potential, field, and charge density as a function of edge-averaged and volume-averaged cell size. Analysis shows second order of convergence for the potential and first order of convergence for the electric field and charge density. Temporal sensitivity analysis is performed and the momentum and energy conservation properties of the particle integrators in EUPIC are examined. The effects of cell size and timestep on heating, slowing-down and the deflection times are quantified. The heating, slowing-down and the deflection times are found to be almost linearly dependent on number of particles per cell. EUPIC simulations of current collection by cylindrical Langmuir probes in collisionless plasmas show good comparison with previous experimentally validated numerical results. These simulations were also used in a parallelization

  9. TU-AB-202-05: GPU-Based 4D Deformable Image Registration Using Adaptive Tetrahedral Mesh Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Z; Zhuang, L [Wayne State University, Detroit, MI (United States); Gu, X; Wang, J [UT Southwestern Medical Center, Dallas, TX (United States); Chen, H; Zhen, X [Southern Medical University, Guangzhou, Guangdong (China)

    2016-06-15

    Purpose: Deformable image registration (DIR) has been employed today as an automated and effective segmentation method to transfer tumor or organ contours from the planning image to daily images, instead of manual segmentation. However, the computational time and accuracy of current DIR approaches are still insufficient for online adaptive radiation therapy (ART), which requires real-time and high-quality image segmentation, especially in a large datasets of 4D-CT images. The objective of this work is to propose a new DIR algorithm, with fast computational speed and high accuracy, by using adaptive feature-based tetrahedral meshing and GPU-based parallelization. Methods: The first step is to generate the adaptive tetrahedral mesh based on the image features of a reference phase of 4D-CT, so that the deformation can be well captured and accurately diffused from the mesh vertices to voxels of the image volume. Subsequently, the deformation vector fields (DVF) and other phases of 4D-CT can be obtained by matching each phase of the target 4D-CT images with the corresponding deformed reference phase. The proposed 4D DIR method is implemented on GPU, resulting in significantly increasing the computational efficiency due to its parallel computing ability. Results: A 4D NCAT digital phantom was used to test the efficiency and accuracy of our method. Both the image and DVF results show that the fine structures and shapes of lung are well preserved, and the tumor position is well captured, i.e., 3D distance error is 1.14 mm. Compared to the previous voxel-based CPU implementation of DIR, such as demons, the proposed method is about 160x faster for registering a 10-phase 4D-CT with a phase dimension of 256×256×150. Conclusion: The proposed 4D DIR method uses feature-based mesh and GPU-based parallelism, which demonstrates the capability to compute both high-quality image and motion results, with significant improvement on the computational speed.

  10. TU-AB-202-05: GPU-Based 4D Deformable Image Registration Using Adaptive Tetrahedral Mesh Modeling

    International Nuclear Information System (INIS)

    Zhong, Z; Zhuang, L; Gu, X; Wang, J; Chen, H; Zhen, X

    2016-01-01

    Purpose: Deformable image registration (DIR) has been employed today as an automated and effective segmentation method to transfer tumor or organ contours from the planning image to daily images, instead of manual segmentation. However, the computational time and accuracy of current DIR approaches are still insufficient for online adaptive radiation therapy (ART), which requires real-time and high-quality image segmentation, especially in a large datasets of 4D-CT images. The objective of this work is to propose a new DIR algorithm, with fast computational speed and high accuracy, by using adaptive feature-based tetrahedral meshing and GPU-based parallelization. Methods: The first step is to generate the adaptive tetrahedral mesh based on the image features of a reference phase of 4D-CT, so that the deformation can be well captured and accurately diffused from the mesh vertices to voxels of the image volume. Subsequently, the deformation vector fields (DVF) and other phases of 4D-CT can be obtained by matching each phase of the target 4D-CT images with the corresponding deformed reference phase. The proposed 4D DIR method is implemented on GPU, resulting in significantly increasing the computational efficiency due to its parallel computing ability. Results: A 4D NCAT digital phantom was used to test the efficiency and accuracy of our method. Both the image and DVF results show that the fine structures and shapes of lung are well preserved, and the tumor position is well captured, i.e., 3D distance error is 1.14 mm. Compared to the previous voxel-based CPU implementation of DIR, such as demons, the proposed method is about 160x faster for registering a 10-phase 4D-CT with a phase dimension of 256×256×150. Conclusion: The proposed 4D DIR method uses feature-based mesh and GPU-based parallelism, which demonstrates the capability to compute both high-quality image and motion results, with significant improvement on the computational speed.

  11. Erasing no-man’s land by thermodynamically stabilizing the liquid-liquid transition in tetrahedral particles

    Science.gov (United States)

    Smallenburg, Frank; Filion, Laura; Sciortino, Francesco

    2014-09-01

    One of the most controversial hypotheses for explaining the origin of the thermodynamic anomalies characterizing liquid water postulates the presence of a metastable second-order liquid-liquid critical point located in the `no-man’s land’. In this scenario, two liquids with distinct local structure emerge near the critical temperature. Unfortunately, as spontaneous crystallization is rapid in this region, experimental support for this hypothesis relies on significant extrapolations, either from the metastable liquid or from amorphous solid water. Although the liquid-liquid transition is expected to feature in many tetrahedrally coordinated liquids, including silicon, carbon and silica, even numerical studies of atomic and molecular models have been unable to conclusively prove the existence of this transition. Here we provide such evidence for a model in which it is possible to continuously tune the softness of the interparticle interaction and the flexibility of the bonds, the key ingredients controlling the existence of the critical point. We show that conditions exist where the full coexistence is thermodynamically stable with respect to crystallization. Our work offers a basis for designing colloidal analogues of water exhibiting liquid-liquid transitions in equilibrium, opening the way for experimental confirmation of the original hypothesis.

  12. Conductivity enhancement of ion tracks in tetrahedral amorphous carbon by doping with N, B, Cu and Fe

    International Nuclear Information System (INIS)

    Krauser, J.; Nix, A.-K.; Gehrke, H.-G.; Hofsäss, H.; Trautmann, C.; Weidinger, A.

    2012-01-01

    Conducting ion tracks are formed when high-energy heavy ions (e.g. 1 GeV Au) pass through tetrahedral amorphous carbon (ta-C). These nanowires with a diameter of about 8 nm are embedded in the insulating ta-C matrix and of interest for various nanotechnological applications. Usually the overall conductivity of the tracks and the current/voltage characteristics (Ohmic or non-Ohmic) vary strongly from track to track, even when measured on the same sample, indicating that the track formation is neither complete nor homogeneous. To improve the track conductivity, doping of ta-C with N, B, Cu, or Fe is investigated. Beneficial changes in track conductivity after doping compete with a conductivity increase of the surrounding matrix material. Best results are achieved by incorporation of 1 at.% Cu, while for different reasons, the improvement of the tracks remains moderate for N, B, and Fe doping. Conductivity enhancement of the tracks is assumed to develop during the ion track formation process by an increased number of localized states which contribute to the current transport.

  13. Effect of nanoparticles as lubricant additives on friction and wear behavior of tetrahedral amorphous carbon (ta-C coating

    Directory of Open Access Journals (Sweden)

    Xiang Li

    2018-03-01

    Full Text Available As diamond like carbon (DLC coating becomes increasingly popular in providing low friction and wear under lubricated conditions, the effect of various oil additives on tribological behavior of DLC coating is drawing more attention. Various oil additives, such as ZnDTP and MoDTC, have been widely used in automobile engine industry to pursuit excellent tribological performance in the insufficient lubrication condition. Although such commercial oil additives have been proven to reduce friction or/and wear to some extent, usage of such high -SAPS (sulphuric ash, phosphor, sulfphur conventional additives is bound to arouse concerns due to environmental reasons. In this research, we investigate the effect of two nanoparticle oil additives, which are cerium oxide (CeO2 and zirconium dioxide (ZrO2, on friction and wear of non-hydrogen tetrahedral amorphous carbon (ta-C coating. The results show that by adding ZrO2 nanoparticle, the friction of DLC coating could be reduced about 32% compared to non-additive base oil scenario, but specific wear rate increases by 40%. When CeO2 nanoparticle is used, friction increases by 22% compared to non-additive base oil scenario, however wear decreases by nearly 77%.

  14. Silicon nitride gradient film as the underlayer of ultra-thin tetrahedral amorphous carbon overcoat for magnetic recording slider

    Energy Technology Data Exchange (ETDEWEB)

    Wang Guigen, E-mail: wanggghit@yahoo.com [Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055 (China); Kuang Xuping; Zhang Huayu; Zhu Can [Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055 (China); Han Jiecai [Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055 (China); Center for Composite Materials, Harbin Institute of Technology, Harbin 150080 (China); Zuo Hongbo [Center for Composite Materials, Harbin Institute of Technology, Harbin 150080 (China); Ma Hongtao [SAE Technologies Development (Dongguan) Co., Ltd., Dongguan 523087 (China)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer The ultra-thin carbon films with different silicon nitride (Si-N) film underlayers were prepared. Black-Right-Pointing-Pointer It highlighted the influences of Si-N underlayers. Black-Right-Pointing-Pointer The carbon films with Si-N underlayers obtained by nitriding especially at the substrate bias of -150 V, can exhibit better corrosion protection properties - Abstract: There are higher technical requirements for protection overcoat of magnetic recording slider used in high-density storage fields for the future. In this study, silicon nitride (Si-N) composition-gradient films were firstly prepared by nitriding of silicon thin films pre-sputtered on silicon wafers and magnetic recording sliders, using microwave electron cyclotron resonance plasma source. The ultra-thin tetrahedral amorphous carbon films were then deposited on the Si-N films by filtered cathodic vacuum arc method. Compared with amorphous carbon overcoats with conventional silicon underlayers, the overcoats with Si-N underlayers obtained by plasma nitriding especially at the substrate bias of -150 V, can provide better corrosion protection for high-density magnetic recording sliders.

  15. Silicon nitride gradient film as the underlayer of ultra-thin tetrahedral amorphous carbon overcoat for magnetic recording slider

    International Nuclear Information System (INIS)

    Wang Guigen; Kuang Xuping; Zhang Huayu; Zhu Can; Han Jiecai; Zuo Hongbo; Ma Hongtao

    2011-01-01

    Highlights: ► The ultra-thin carbon films with different silicon nitride (Si-N) film underlayers were prepared. ► It highlighted the influences of Si-N underlayers. ► The carbon films with Si-N underlayers obtained by nitriding especially at the substrate bias of −150 V, can exhibit better corrosion protection properties - Abstract: There are higher technical requirements for protection overcoat of magnetic recording slider used in high-density storage fields for the future. In this study, silicon nitride (Si-N) composition-gradient films were firstly prepared by nitriding of silicon thin films pre-sputtered on silicon wafers and magnetic recording sliders, using microwave electron cyclotron resonance plasma source. The ultra-thin tetrahedral amorphous carbon films were then deposited on the Si-N films by filtered cathodic vacuum arc method. Compared with amorphous carbon overcoats with conventional silicon underlayers, the overcoats with Si-N underlayers obtained by plasma nitriding especially at the substrate bias of −150 V, can provide better corrosion protection for high-density magnetic recording sliders.

  16. Antimalarial, antimicrobial, cytotoxic, DNA interaction and SOD like activities of tetrahedral copper(II) complexes

    Science.gov (United States)

    Mehta, Jugal V.; Gajera, Sanjay B.; Patel, Mohan N.

    2015-02-01

    The mononuclear copper(II) complexes with P, O-donor ligand and different fluoroquinolones have been synthesized and characterized by elemental analysis, electronic spectra, TGA, EPR, FT-IR and LC-MS spectroscopy. An antimicrobial efficiency of the complexes has been tested against five different microorganisms in terms of minimum inhibitory concentration (MIC) and displays very good antimicrobial activity. The binding strength and binding mode of the complexes with Herring Sperm DNA (HS DNA) have been investigated by absorption titration and viscosity measurement studies. The studies suggest the classical intercalative mode of DNA binding. Gel electrophoresis assay determines the ability of the complexes to cleave the supercoiled form of pUC19 DNA. Synthesized complexes have been tested for their SOD mimic activity using nonenzymatic NBT/NADH/PMS system and found to have good antioxidant activity. All the complexes show good cytotoxic and in vitro antimalarial activities.

  17. Cause and Cure-Deterioration in Accuracy of CFD Simulations with Use of High-Aspect-Ratio Triangular/Tetrahedral Grids

    Science.gov (United States)

    Chang, Sin-Chung; Chang, Chau-Lyan; Venkatachari, Balaji

    2017-01-01

    In the multi-dimensional space-time conservation element and solution element16 (CESE) method, triangles and tetrahedral mesh elements turn out to be the most natural building blocks for 2D and 3D spatial grids, respectively. As such, the CESE method is naturally compatible with the simplest 2D and 3D unstructured grids and thus can be easily applied to solve problems with complex geometries. However, because (a) accurate solution of a high-Reynolds number flow field near a solid wall requires that the grid intervals along the direction normal to the wall be much finer than those in a direction parallel to the wall and, as such, the use of grid cells with extremely high aspect ratio (103 to 106) may become mandatory, and (b) unlike quadrilateral hexahedral grids, it is well-known that accuracy of gradient computations involving triangular tetrahedral grids tends to deteriorate rapidly as cell aspect ratio increases. As a result, the use of triangular tetrahedral grid cells near a solid wall has long been deemed impractical by CFD researchers. In view of (a) the critical role played by triangular tetrahedral grids in the CESE development, and (b) the importance of accurate resolution of high-Reynolds number flow field near a solid wall, as will be presented in the main paper, a comprehensive and rigorous mathematical framework that clearly identifies the reasons behind the accuracy deterioration as described above has been developed for the 2D case involving triangular cells. By avoiding the pitfalls identified by the 2D framework, and its 3D extension, it has been shown numerically.

  18. A Deep Penetration Problem Calculation Using AETIUS:An Easy Modeling Discrete Ordinates Transport Code UsIng Unstructured Tetrahedral Mesh, Shared Memory Parallel

    Science.gov (United States)

    KIM, Jong Woon; LEE, Young-Ouk

    2017-09-01

    As computing power gets better and better, computer codes that use a deterministic method seem to be less useful than those using the Monte Carlo method. In addition, users do not like to think about space, angles, and energy discretization for deterministic codes. However, a deterministic method is still powerful in that we can obtain a solution of the flux throughout the problem, particularly as when particles can barely penetrate, such as in a deep penetration problem with small detection volumes. Recently, a new state-of-the-art discrete-ordinates code, ATTILA, was developed and has been widely used in several applications. ATTILA provides the capabilities to solve geometrically complex 3-D transport problems by using an unstructured tetrahedral mesh. Since 2009, we have been developing our own code by benchmarking ATTILA. AETIUS is a discrete ordinates code that uses an unstructured tetrahedral mesh such as ATTILA. For pre- and post- processing, Gmsh is used to generate an unstructured tetrahedral mesh by importing a CAD file (*.step) and visualizing the calculation results of AETIUS. Using a CAD tool, the geometry can be modeled very easily. In this paper, we describe a brief overview of AETIUS and provide numerical results from both AETIUS and a Monte Carlo code, MCNP5, in a deep penetration problem with small detection volumes. The results demonstrate the effectiveness and efficiency of AETIUS for such calculations.

  19. Finite-element design and optimization of a three-dimensional tetrahedral porous titanium scaffold for the reconstruction of mandibular defects.

    Science.gov (United States)

    Luo, Danmei; Rong, Qiguo; Chen, Quan

    2017-09-01

    Reconstruction of segmental defects in the mandible remains a challenge for maxillofacial surgery. The use of porous scaffolds is a potential method for repairing these defects. Now, additive manufacturing techniques provide a solution for the fabrication of porous scaffolds with specific geometrical shapes and complex structures. The goal of this study was to design and optimize a three-dimensional tetrahedral titanium scaffold for the reconstruction of mandibular defects. With a fixed strut diameter of 0.45mm and a mean cell size of 2.2mm, a tetrahedral structural porous scaffold was designed for a simulated anatomical defect derived from computed tomography (CT) data of a human mandible. An optimization method based on the concept of uniform stress was performed on the initial scaffold to realize a minimal-weight design. Geometric and mechanical comparisons between the initial and optimized scaffold show that the optimized scaffold exhibits a larger porosity, 81.90%, as well as a more homogeneous stress distribution. These results demonstrate that tetrahedral structural titanium scaffolds are feasible structures for repairing mandibular defects, and that the proposed optimization scheme has the ability to produce superior scaffolds for mandibular reconstruction with better stability, higher porosity, and less weight. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  20. Three-dimensional dynamic rupture simulation with a high-order discontinuous Galerkin method on unstructured tetrahedral meshes

    KAUST Repository

    Pelties, Christian

    2012-02-18

    Accurate and efficient numerical methods to simulate dynamic earthquake rupture and wave propagation in complex media and complex fault geometries are needed to address fundamental questions in earthquake dynamics, to integrate seismic and geodetic data into emerging approaches for dynamic source inversion, and to generate realistic physics-based earthquake scenarios for hazard assessment. Modeling of spontaneous earthquake rupture and seismic wave propagation by a high-order discontinuous Galerkin (DG) method combined with an arbitrarily high-order derivatives (ADER) time integration method was introduced in two dimensions by de la Puente et al. (2009). The ADER-DG method enables high accuracy in space and time and discretization by unstructured meshes. Here we extend this method to three-dimensional dynamic rupture problems. The high geometrical flexibility provided by the usage of tetrahedral elements and the lack of spurious mesh reflections in the ADER-DG method allows the refinement of the mesh close to the fault to model the rupture dynamics adequately while concentrating computational resources only where needed. Moreover, ADER-DG does not generate spurious high-frequency perturbations on the fault and hence does not require artificial Kelvin-Voigt damping. We verify our three-dimensional implementation by comparing results of the SCEC TPV3 test problem with two well-established numerical methods, finite differences, and spectral boundary integral. Furthermore, a convergence study is presented to demonstrate the systematic consistency of the method. To illustrate the capabilities of the high-order accurate ADER-DG scheme on unstructured meshes, we simulate an earthquake scenario, inspired by the 1992 Landers earthquake, that includes curved faults, fault branches, and surface topography. Copyright 2012 by the American Geophysical Union.

  1. Decoration of the Truncated Tetrahedron—An Archimedean Polyhedron—To Produce a New Class of Convex Equilateral Polyhedra with Tetrahedral Symmetry

    Directory of Open Access Journals (Sweden)

    Stan Schein

    2016-08-01

    Full Text Available The Goldberg construction of symmetric cages involves pasting a patch cut out of a regular tiling onto the faces of a Platonic host polyhedron, resulting in a cage with the same symmetry as the host. For example, cutting equilateral triangular patches from a 6.6.6 tiling of hexagons and pasting them onto the full triangular faces of an icosahedron produces icosahedral fullerene cages. Here we show that pasting cutouts from a 6.6.6 tiling onto the full hexagonal and triangular faces of an Archimedean host polyhedron, the truncated tetrahedron, produces two series of tetrahedral (Td fullerene cages. Cages in the first series have 28n2 vertices (n ≥ 1. Cages in the second (leapfrog series have 3 × 28n2. We can transform all of the cages of the first series and the smallest cage of the second series into geometrically convex equilateral polyhedra. With tetrahedral (Td symmetry, these new polyhedra constitute a new class of “convex equilateral polyhedra with polyhedral symmetry”. We also show that none of the other Archimedean polyhedra, six with octahedral symmetry and six with icosahedral, can host full-face cutouts from regular tilings to produce cages with the host’s polyhedral symmetry.

  2. Structural characterization of rondorfite, calcium silica chlorine mineral containing magnesium in tetrahedral position [MgO4]6-, with the aid of the vibrational spectroscopies and fluorescence.

    Science.gov (United States)

    Dulski, M; Bulou, A; Marzec, K M; Galuskin, E V; Wrzalik, R

    2013-01-15

    Raman and infrared spectra of rondorfite Ca8Mg(SiO4)4Cl2, a calcium chlorosilica mineral containing magnesium in tetrahedral position, has been studied in terms of spectra-structure relations. Raman spectra have been measured at different excited laser lines: 780 nm, 532 nm, 488 nm and 457 nm. This mineral is characterized by a single sharp intense Raman band at 863 cm(-1) assigned to the ν1 [SiO4]4- (Ag) symmetric stretching mode in the magnesiosilicate pentamer. Due to symmetry restriction the other Raman bands have a small intensity. Two Raman bands observed at 564 cm(-1) and 526 cm(-1) are associated simultaneously with ν4 [MgO4]6- and ν4 [SiO4]4- symmetric and antisymmetric modes where magnesium occurs in the tetrahedral configuration. The weak bands at 422 cm(-1) and 386 cm(-1) are associated with the ν2 bending mode of CaO6 in octahedral configuration, respectively. Moreover the infrared spectrum shows very weak bands associated with the hydroxyl group and/or water molecule. Additionally, the strong fluorescence phenomenon was observed and related to the presence of chlorine atoms, magnesium Mg2+ ions in atypical configuration or point defects. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Tetrahedral cluster and pseudo molecule: New approaches to Calculate Absolute Surface Energy of Zinc Blende (111)/(-1-1-1) Surface

    Science.gov (United States)

    Zhang, Yiou; Zhang, Jingzhao; Tse, Kinfai; Wong, Lun; Chan, Chunkai; Deng, Bei; Zhu, Junyi

    Determining accurate absolute surface energies for polar surfaces of semiconductors has been a great challenge in decades. Here, we propose pseudo-hydrogen passivation to calculate them, using density functional theory approaches. By calculating the energy contribution from pseudo-hydrogen using either a pseudo molecule method or a tetrahedral cluster method, we obtained (111)/(-1-1-1) surfaces energies of Si, GaP, GaAs, and ZnS with high self-consistency. Our findings may greatly enhance the basic understandings of different surfaces and lead to novel strategies in the crystal growth. We would like to thank Su-huai Wei for helpful discussions. Computing resources were provided by the High Performance Cluster Computing Centre, Hong Kong Baptist University. This work was supported by the start-up funding and direct Grant with the Project.

  4. On the ground-state degeneracy and entropy in a double-tetrahedral chain formed by the localized Ising spins and mobile electrons

    Science.gov (United States)

    Gálisová, Lucia

    2018-05-01

    Ground-state properties of a hybrid double-tetrahedral chain, in which the localized Ising spins regularly alternate with triangular plaquettes occupied by a variable number of mobile electrons, are exactly investigated. We demonstrate that the zero-temperature phase diagram of the model involves several non-degenerate, two-fold degenerate and macroscopically degenerate chiral phases. Low-temperature dependencies of the entropy and specific heat are also examined in order to gain a deeper insight into the degeneracy of individual ground-state phases and phase transitions. It is shown that a diversity of the ground-state degeneracy manifests itself in multiple-peak structures of both thermodynamic quantities. A remarkable temperature dependencies of the specific heat with two and three Schottky-type maxima are discussed in detail.

  5. COMPUTATIONAL EFFICIENCY OF A MODIFIED SCATTERING KERNEL FOR FULL-COUPLED PHOTON-ELECTRON TRANSPORT PARALLEL COMPUTING WITH UNSTRUCTURED TETRAHEDRAL MESHES

    Directory of Open Access Journals (Sweden)

    JONG WOON KIM

    2014-04-01

    In this paper, we introduce a modified scattering kernel approach to avoid the unnecessarily repeated calculations involved with the scattering source calculation, and used it with parallel computing to effectively reduce the computation time. Its computational efficiency was tested for three-dimensional full-coupled photon-electron transport problems using our computer program which solves the multi-group discrete ordinates transport equation by using the discontinuous finite element method with unstructured tetrahedral meshes for complicated geometrical problems. The numerical tests show that we can improve speed up to 17∼42 times for the elapsed time per iteration using the modified scattering kernel, not only in the single CPU calculation but also in the parallel computing with several CPUs.

  6. Oxygen trapped by rare earth tetrahedral clusters in Nd4FeOS6: Crystal structure, electronic structure, and magnetic properties

    International Nuclear Information System (INIS)

    Lin, Qisheng; Taufour, Valentin; Zhang, Yuemei; Wood, Max; Drtina, Thomas; Bud’ko, Sergey L.; Canfield, Paul C.; Miller, Gordon J.

    2015-01-01

    Single crystals of Nd 4 FeOS 6 were grown from an Fe–S eutectic solution. Single crystal X-ray diffraction analysis revealed a Nd 4 MnOSe 6 -type structure (P6 3 mc, a=9.2693(1) Å, c=6.6650(1)Å, V=495.94(1) Å 3 , Z=2), featuring parallel chains of face-sharing [FeS 6×1/2 ] 4− trigonal antiprisms and interlinked [Nd 4 OS 3 ] 4+ cubane-like clusters. Oxygen atoms were found to be trapped by Nd 4 clusters in the [Nd 4 OS 3 ] 4 + chains. Structural differences among Nd 4 MnOSe 6 -type Nd 4 FeOS 6 and the related La 3 CuSiS 7 − and Pr 8 CoGa 3 -type structures have been described. Magnetic susceptibility measurements on Nd 4 FeOS 6 suggested the dominance of antiferromagnetic interactions at low temperature, but no magnetic ordering down to 2 K was observed. Spin-polarized electronic structure calculations revealed magnetic frustration with dominant antiferromagnetic interactions. - Graphical abstract: Trapping of oxygen in Nd 4 tetrahedral clusters results in the formation of the Nd 4 MnOSe 6 -type Nd 4 FeOS 6 , in contrast to the La 3 CuSiS 7 -type oxygen-free Nd 4 FeS 7 and related Pr 8 CoGa 3 -type structures. Complex magnetic frustration inhibits magnetic ordering at low temperature. - Highlights: • Single crystals of Nd 4 FeOS 6 were grown using self-flux method. • Oxygen was found trapped by Nd 4 tetrahedral clusters. • Comparison with two closely related structural types were discussed. • Magnetic measurements revealed antiferromagnetic (AFM) interaction. • VASP calculations confirmed strong magnetic frustration in AFM model

  7. Recent Development in the CESE Method for the Solution of the Navier-Stokes Equations Using Unstructured Triangular or Tetrahedral Meshes With High Aspect Ratio

    Science.gov (United States)

    Chang, Sin-Chung; Chang, Chau-Lyan; Yen, Joseph C.

    2013-01-01

    In the multidimensional CESE development, triangles and tetrahedra turn out to be the most natural building blocks for 2D and 3D spatial meshes. As such the CESE method is compatible with the simplest unstructured meshes and thus can be easily applied to solve problems with complex geometries. However, because the method uses space-time staggered stencils, solution decoupling may become a real nuisance in applications involving unstructured meshes. In this paper we will describe a simple and general remedy which, according to numerical experiments, has removed any possibility of solution decoupling. Moreover, in a real-world viscous flow simulation near a solid wall, one often encounters a case where a boundary with high curvature or sharp corner is surrounded by triangular/tetrahedral meshes of extremely high aspect ratio (up to 106). For such an extreme case, the spatial projection of a space-time compounded conservation element constructed using the original CESE design may become highly concave and thus its centroid (referred to as a spatial solution point) may lie far outside of the spatial projection. It could even be embedded beyond a solid wall boundary and causes serious numerical difficulties. In this paper we will also present a new procedure for constructing conservation elements and solution elements which effectively overcomes the difficulties associated with the original design. Another difficulty issue which was addressed more recently is the wellknown fact that accuracy of gradient computations involving triangular/tetrahedral grids deteriorates rapidly as the aspect ratio of grid cells increases. The root cause of this difficulty was clearly identified and several remedies to overcome it were found through a rigorous mathematical analysis. However, because of the length of the current paper and the complexity of mathematics involved, this new work will be presented in another paper.

  8. Symmetries of the octonionic root system of E8

    International Nuclear Information System (INIS)

    Koca, M.

    1990-09-01

    Octonionic root system of E 8 is decomposed as the 9 sets of Hurwitz integers, each set satisfying the binary tetrahedral group structure, and the 12 sets of quaternionic units, each set obeying the dicyclic group structure of order 12. This fact is used to prove that the automorphism group of the octonionic root system of E 7 is the finite subgroup of G 2 , of order 12096; an explicit 7 x 7 matrix realization of which is constructed. Possible use of the octonionic representation of the E 6 root system as orbifolds and the relevance of the binary tetrahedral structures with the statistical mechanics models are suggested. (author). 16 refs, 6 figs

  9. How do glycerol and dimethyl sulphoxide affect local tetrahedral structure of water around a nonpolar solute at low temperature? Importance of preferential interaction

    Science.gov (United States)

    Daschakraborty, Snehasis

    2018-04-01

    Glycerol and dimethyl sulphoxide (DMSO) have vital roles in cryoprotection of living cells, tissues, etc. The above action has been directly linked with disruption of hydrogen (H-) bond structure and dynamics of water by these cosolvents at bulk region and around various complex units, such as peptide, amino acid, protein, and lipid membrane. However, the disruption of the local structure of the water solvent around a purely hydrophobic solute is still not studied extensively. The latter is also important in the context of stabilization of protein from cold denaturation. Through all-atom molecular dynamics simulation, we have investigated the comparative effect of glycerol and DMSO on the orientational order of water around a nonpolar solute at -5 °C. A steady reduction of the tetrahedral order of water is observed at bulk (>10 Å distance from the solute) and solute interface (structure of the interfacial water more than that of the bulk water, glycerol affects the water structure almost uniformly at all regions around the solute. Furthermore, while glycerol helps to retain water molecules at the interface, DMSO significantly reduces the water content in that region. We have put forward a plausible mechanism for these contrasting roles of these cosolvents. The solute-cosolvent hydrophobic-interaction-induced orientational alignment of an interfacial cosolvent molecule determines whether the involvement of the cosolvent molecules in H-bonding with solvent water in the interface is akin to the bulk region or not.

  10. BeP2: a tetrahedral structure of type order-disorder which obeys a coordination rule for short-range order

    International Nuclear Information System (INIS)

    L'Haridon, P.; David, J.; Lang, J.; Parthe, E.

    1976-01-01

    Single-crystal studies on BeP 2 indicate that this compound possesses an OD structure. The substructure has a tetragonal unit cell with: a = 3.546 A, c = 15.01 A, Z = 4, space group: I4 1 /amd. The final R factor has a value of 0.033. The atom sites in this substructure correspond to the sites of diamond if the latter is described with a tetragonal cell, where a = (2/sup 1/2//a/sub diamond/ and c = 3a/sub diamond/. A short-range order governs the occupation of these sites with Be and P atoms. Each Be has four tetrahedral P neighbors and every P has two Be and two P neighbors. Consideration of the maxima on the diffuse streaks between the sharp reflectins of the substructure leads to an intermediate unit cell with a = 7.09 A and c = 30.02 A. Coordination considerations allow a structure proposal to be formulated for this intermediate structure which is triclinic but pseudotetragonal. The true unit cell is also pseudotetragonal with a = 7.09 A and c = N . 15.01 A, where N is a large integer

  11. Comprehensive understanding of mole concept subject matter according to the tetrahedral chemistry education (empirical study on the first-year chemistry students of Technische Universität Dresden)

    Science.gov (United States)

    Prabowo, D. W.; Mulyani, S.; van Pée, K.-H.; Indriyanti, N. Y.

    2018-05-01

    This research aims to apprehend: (1) the shape of tetrahedral chemistry education which is called the future of chemistry education, (2) comprehensive understanding of chemistry first-year students of Technische Universität Dresden according to the chemistry education’s tetrahedral shape on mole concept subject matter. This research used quantitative and qualitative; paper and pencil test and interview. The former was conducted in the form of test containing objective test instrument. The results of this study are (1) learning based on tetrahedral shape of chemistry education put the chemical substance (macroscopic), symbolic representation (symbol), and its process (molecular) in the context of human beings (human element) by integrating content and context, without emphasis on one thing and weaken another, (2) first-year chemistry students of Technische Universität Dresden have comprehensively understood the mole concept associated with the context of everyday life, whereby students are able to find out macroscopic information from statements that are contextual to human life and then by using symbols and formulas are able to comprehend the molecular components as well as to interpret and analyse problems effectively.

  12. Nuclear Magnetic Shielding of Monoboranes: Calculation and Assessment of B-11 NMR Chemical Shifts in Planar BX3 and in Tetrahedral [BX4](-) Systems

    Czech Academy of Sciences Publication Activity Database

    Macháček, Jan; Bühl, M.; Fanfrlík, Jindřich; Hnyk, Drahomír

    2017-01-01

    Roč. 121, č. 50 (2017), s. 9631-9637 ISSN 1089-5639 R&D Projects: GA ČR(CZ) GA17-08045S Institutional support: RVO:61388980 ; RVO:61388963 Keywords : Electrostatic potentials * Nonrelativistic * Nuclear magnetic shieldings Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 2.847, year: 2016

  13. Effect of mating materials on wear properties of amorphous hydrogenated carbon (a-C:H coating and tetrahedral amorphous carbon (ta-C coating in base oil boundary lubrication condition

    Directory of Open Access Journals (Sweden)

    Xiang Li

    2017-12-01

    Full Text Available In this study, wear behavior of amorphous hydrogenated carbon (a-C:H coating and tetrahedral amorphous carbon (ta-C coating when sliding against various mating materials in base oil boundary lubrication condition is comparatively investigated to find out the optimal combinations of DLC/mating material and corresponding wear mechanism of both DLC coating. Tribological tests were performed in a cylinder-on-disc tribometer, Field Emission Scanning Electron Microscopy, Raman spectroscopy is used for characterization of ta-C and a-C:H worn surface. The results show that the specific wear rate of ta-C coating increases along with the hardness and roughness of mating material increases, while the specific wear rate of a-C:H coating increases together with an increment in the ID/IG ratio. It is concluded that for ta-C coating, local stress concentration-induced microfracture is the main wear mechanism in relative high wear scenario, along with minor graphitization-induced wear which prevails in low wear scenario. On the other hand, a-C:H coating showed that simultaneous generation and removal of the graphitized layer on the contact surface is the predominant wear mechanism.

  14. Electronic and optical properties of the LiCdX (X = N, P, As and Sb) filled-tetrahedral compounds with the Tran–Blaha modified Becke–Johnson density functional

    International Nuclear Information System (INIS)

    Bouhemadou, A.; Bin-Omran, S.; Allali, D.; Al-Otaibi, S.M.; Khenata, R.; Al-Douri, Y.; Chegaar, M.; Reshak, A.H.

    2015-01-01

    Highlights: • Electronic and optical properties of the LiCdX compounds have been predicted. • Tran–Blaha-modified Becke–Johnson functional significantly improves the band gap. • We predict a direct band gap in all of the considered LiCdX compounds. • Origin of the peaks in the optical spectra is determined. - Abstract: The structural, electronic and optical properties of the LiCdN, LiCdP, LiCdAs and LiCdSb filled-tetrahedral compounds have been explored from first-principles. The calculated structural parameters are consistent with the available experimental results. Since DFT with the common LDA and GGA underestimates the band gap, we use a new developed functional able to accurately describe the electronic structure of semiconductors, namely the Tran–Blaha-modified Becke–Johnson potential. The four investigated compounds demonstrate semiconducting behavior with direct band gap ranging from about 0.32 to 1.65 eV. The charge-carrier effective masses are evaluated at the topmost valence band and at the bottommost conduction band. The evolution of the value and nature of the energy band gap under pressure effect is also investigated. The frequency-dependent complex dielectric function and some macroscopic optical constants are estimated. The microscopic origins of the structures in the optical spectra are determined in terms of the calculated energy band structures

  15. Electronic and optical properties of the LiCdX (X = N, P, As and Sb) filled-tetrahedral compounds with the Tran–Blaha modified Becke–Johnson density functional

    Energy Technology Data Exchange (ETDEWEB)

    Bouhemadou, A., E-mail: a_bouhemadou@yahoo.fr [Laboratory for Developing New Materials and their Characterization, University of Setif 1, Setif 19000 (Algeria); Bin-Omran, S. [Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Department of Physics, Faculty of Science & Humanitarian Studies, Salman Bin Abdalaziz University, Alkharj 11942 (Saudi Arabia); Allali, D. [Laboratory for Developing New Materials and their Characterization, University of Setif 1, Setif 19000 (Algeria); Al-Otaibi, S.M. [Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Khenata, R. [Laboratoire de Physique Quantique et de Modélisation Mathématique (LPQ3M), Département de Technologie, Université de Mascara, Mascara 29000 (Algeria); Al-Douri, Y. [Institute of Nano Electronic Engineering, Universiti Malaysia Perlis, Kangar, Perlis 01000 (Malaysia); Chegaar, M. [Department of Physics, Faculty of Science, University of Setif 1, Setif 19000 (Algeria); Reshak, A.H. [New Technologies-Research Center, University of West Bohemia, Univerzitni 8, Pilson 306 14 (Czech Republic); Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, Kangar, Perlis 01007 (Malaysia)

    2015-04-15

    Highlights: • Electronic and optical properties of the LiCdX compounds have been predicted. • Tran–Blaha-modified Becke–Johnson functional significantly improves the band gap. • We predict a direct band gap in all of the considered LiCdX compounds. • Origin of the peaks in the optical spectra is determined. - Abstract: The structural, electronic and optical properties of the LiCdN, LiCdP, LiCdAs and LiCdSb filled-tetrahedral compounds have been explored from first-principles. The calculated structural parameters are consistent with the available experimental results. Since DFT with the common LDA and GGA underestimates the band gap, we use a new developed functional able to accurately describe the electronic structure of semiconductors, namely the Tran–Blaha-modified Becke–Johnson potential. The four investigated compounds demonstrate semiconducting behavior with direct band gap ranging from about 0.32 to 1.65 eV. The charge-carrier effective masses are evaluated at the topmost valence band and at the bottommost conduction band. The evolution of the value and nature of the energy band gap under pressure effect is also investigated. The frequency-dependent complex dielectric function and some macroscopic optical constants are estimated. The microscopic origins of the structures in the optical spectra are determined in terms of the calculated energy band structures.

  16. Tribological properties of amorphous hydrogenated (a-C:H) and hydrogen-free tetrahedral (ta-C) diamond-like carbon coatings under jatropha biodegradable lubricating oil at different temperatures

    Science.gov (United States)

    Mobarak, H. M.; Masjuki, H. H.; Mohamad, E. Niza; Kalam, M. A.; Rashedul, H. K.; Rashed, M. M.; Habibullah, M.

    2014-10-01

    The application of diamond-like carbon (DLC) coatings on automotive components is emerging as a favorable strategy to address the recent challenges in the industry. DLC coatings can effectively lower the coefficient of friction (CoF) and wear rate of engine components, thereby improving their fuel efficiency and durability. The lubrication of ferrous materials can be enhanced by a large amount of unsaturated and polar components of oils. Therefore, the interaction between nonferrous coatings (e.g., DLC) and vegetable oil should be investigated. A ball-on-plate tribotester was used to run the experiments. Stainless steel plates coated with amorphous hydrogenated (a-C:H) DLC and hydrogen-free tetrahedral (ta-C) DLC that slide against 440C stainless steel ball were used to create a ball-on-plate tribotester. The wear track was investigated through scanning electron microscopy. Energy dispersive and X-ray photoelectron spectroscopies were used to analyze the tribofilm inside the wear track. Raman analysis was performed to investigate the structural changes in the coatings. At high temperatures, the CoF in both coatings decreased. The wear rate, however, increased in the a-C:H but decreased in the ta-C DLC-coated plates. The CoF and the wear rate (coated layer and counter surface) were primarily influenced by the graphitization of the coating. Tribochemical films, such as polyphosphate glass, were formed in ta-C and acted as protective layers. Therefore, the wear rate of the ta-C DLC was lower than that of the-C:H DLC.

  17. Local Nonobtuse Tetrahedral Refinements of a Cube

    Czech Academy of Sciences Publication Activity Database

    Korotov, S.; Křížek, Michal

    2003-01-01

    Roč. 16, - (2003), s. 1101-1104 ISSN 0893-9659 R&D Projects: GA AV ČR IAA1019201 Institutional research plan: CEZ:AV0Z1019905 Keywords : finite-element method * nonobtuse tetrahedron * path tetrahedron Subject RIV: BA - General Mathematics Impact factor: 0.395, year: 2003

  18. Planet map generation by tetrahedral subdivision

    DEFF Research Database (Denmark)

    Mogensen, Torben Ægidius

    2010-01-01

    We present a method for generating pseudo-random, zoomable planet maps for games and art.  The method is based on spatial subdivision using tetrahedrons.  This ensures planet maps without discontinuities caused by mapping a flat map onto a sphere. We compare the method to other map...

  19. Tribological properties of amorphous hydrogenated (a-C:H) and hydrogen-free tetrahedral (ta-C) diamond-like carbon coatings under jatropha biodegradable lubricating oil at different temperatures

    International Nuclear Information System (INIS)

    Mobarak, H.M.; Masjuki, H.H.; Mohamad, E. Niza; Kalam, M.A.; Rashedul, H.K.; Rashed, M.M.; Habibullah, M.

    2014-01-01

    Highlights: • We tested a-C:H and ta-C DLC coatings as a function of temperature. • Jatropha oil contains large amounts of polar components that enhanced the lubricity of coatings. • CoF decreases with increasing temperature for both contacts. • Wear rate increases with increasing temperature in a-C:H and decreases in ta-C DLC. • At high temperature, ta-C coatings confer more protection than a-C:H coatings. - Abstract: The application of diamond-like carbon (DLC) coatings on automotive components is emerging as a favorable strategy to address the recent challenges in the industry. DLC coatings can effectively lower the coefficient of friction (CoF) and wear rate of engine components, thereby improving their fuel efficiency and durability. The lubrication of ferrous materials can be enhanced by a large amount of unsaturated and polar components of oils. Therefore, the interaction between nonferrous coatings (e.g., DLC) and vegetable oil should be investigated. A ball-on-plate tribotester was used to run the experiments. Stainless steel plates coated with amorphous hydrogenated (a-C:H) DLC and hydrogen-free tetrahedral (ta-C) DLC that slide against 440C stainless steel ball were used to create a ball-on-plate tribotester. The wear track was investigated through scanning electron microscopy. Energy dispersive and X-ray photoelectron spectroscopies were used to analyze the tribofilm inside the wear track. Raman analysis was performed to investigate the structural changes in the coatings. At high temperatures, the CoF in both coatings decreased. The wear rate, however, increased in the a-C:H but decreased in the ta-C DLC-coated plates. The CoF and the wear rate (coated layer and counter surface) were primarily influenced by the graphitization of the coating. Tribochemical films, such as polyphosphate glass, were formed in ta-C and acted as protective layers. Therefore, the wear rate of the ta-C DLC was lower than that of the-C:H DLC

  20. Tribological properties of amorphous hydrogenated (a-C:H) and hydrogen-free tetrahedral (ta-C) diamond-like carbon coatings under jatropha biodegradable lubricating oil at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Mobarak, H.M., E-mail: mobarak.ho31@yahoo.com; Masjuki, H.H.; Mohamad, E. Niza, E-mail: edzrol@um.edu.my; Kalam, M.A.; Rashedul, H.K.; Rashed, M.M.; Habibullah, M.

    2014-10-30

    Highlights: • We tested a-C:H and ta-C DLC coatings as a function of temperature. • Jatropha oil contains large amounts of polar components that enhanced the lubricity of coatings. • CoF decreases with increasing temperature for both contacts. • Wear rate increases with increasing temperature in a-C:H and decreases in ta-C DLC. • At high temperature, ta-C coatings confer more protection than a-C:H coatings. - Abstract: The application of diamond-like carbon (DLC) coatings on automotive components is emerging as a favorable strategy to address the recent challenges in the industry. DLC coatings can effectively lower the coefficient of friction (CoF) and wear rate of engine components, thereby improving their fuel efficiency and durability. The lubrication of ferrous materials can be enhanced by a large amount of unsaturated and polar components of oils. Therefore, the interaction between nonferrous coatings (e.g., DLC) and vegetable oil should be investigated. A ball-on-plate tribotester was used to run the experiments. Stainless steel plates coated with amorphous hydrogenated (a-C:H) DLC and hydrogen-free tetrahedral (ta-C) DLC that slide against 440C stainless steel ball were used to create a ball-on-plate tribotester. The wear track was investigated through scanning electron microscopy. Energy dispersive and X-ray photoelectron spectroscopies were used to analyze the tribofilm inside the wear track. Raman analysis was performed to investigate the structural changes in the coatings. At high temperatures, the CoF in both coatings decreased. The wear rate, however, increased in the a-C:H but decreased in the ta-C DLC-coated plates. The CoF and the wear rate (coated layer and counter surface) were primarily influenced by the graphitization of the coating. Tribochemical films, such as polyphosphate glass, were formed in ta-C and acted as protective layers. Therefore, the wear rate of the ta-C DLC was lower than that of the-C:H DLC.

  1. Dielectric and optical properties of glasses of CdO-B2O3 system

    International Nuclear Information System (INIS)

    Semin, V.N.; Mal'tsev, V.T.; Panich, A.E.

    1986-01-01

    Dielectric and optical properties of glasses of CdO-B 2 O 3 system are investigated. It is shown, that on changing the composition, cadmic-borate glasses undergo structural changes, similar to those, taking place in lead-borate glasses, and the maximum part of the boron atoms in the oxygen tetrahedral coordination is at CdO:B 2 O 3 =3:2

  2. 73Ge, 119Sn and 207Pb: general cooperative effects of single atom ligands on the NMR signals observed in tetrahedral [MXnY4-n] (M = Ge, Sn, Pb; 1 ≤ n ≤ 4; X, Y = Cl, Br, I) coordination compounds of heavier XIV group elements.

    Science.gov (United States)

    Benedetti, M; De Castro, F; Fanizzi, F P

    2017-02-28

    An inverse linear relationship between 73 Ge, 119 Sn and 207 Pb NMR chemical shifts and the overall sum of ionic radii of coordinated halido ligands has been discovered in tetrahedral [MX n Y 4-n ] (M = Ge, Sn, Pb; 1 ≤ n ≤ 4; X, Y = Cl, Br, I) coordination compounds. This finding is consistent with a previously reported correlation found in octahedral, pentacoordinate and square planar platinum complexes. The effect of the coordinated halido ligands acting on the metal as shielding conducting rings is therefore confirmed also by 73 Ge, 119 Sn and 207 Pb NMR spectroscopy.

  3. Clinical use of the hyperthermia treatment planning system HyperPlan to predict effectiveness and toxicity

    International Nuclear Information System (INIS)

    Sreenivasa, Geetha; Gellermann, Johanna; Rau, Beate; Nadobny, Jacek; Schlag, Peter; Deuflhard, Peter; Felix, Roland; Wust, Peter

    2003-01-01

    Purpose: The main aim is to prove the clinical practicability of the hyperthermia treatment planning system HyperPlan on a β-test level. Data and observations obtained from clinical hyperthermia are compared with the numeric methods FE (finite element) and FDTD (finite difference time domain), respectively. Methods and Materials: The planning system HyperPlan is built on top of the modular, object-oriented platform for visualization and model generation AMIRA. This system already contains powerful algorithms for image processing, geometric modeling, and three-dimensional graphics display. A number of hyperthermia-specific modules are provided, enabling the creation of three-dimensional tetrahedral patient models suitable for treatment planning. Two numeric methods, FE and FDTD, are implemented in HyperPlan for solving Maxwell's equations. Both methods base their calculations on segmented (contour based) CT or MR image data. A tetrahedral grid is generated from the segmented tissue boundaries, consisting of approximately 80,000 tetrahedrons per patient. The FE method necessitates, primarily, this tetrahedral grid for the calculation of the E-field. The FDTD method, on the other hand, calculates the E-field on a cubical grid, but also requires a tetrahedral grid for correction at electrical interfaces. In both methods, temperature distributions are calculated on the tetrahedral grid by solving the bioheat transfer equation with the FE method. Segmentation, grid generation, E-field, and temperature calculation can be carried out in clinical practice at an acceptable time expenditure of about 1-2 days. Results: All 30 patients we analyzed with cervical, rectal, and prostate carcinoma exhibit a good correlation between the model calculations and the attained clinical data regarding acute toxicity (hot spots), prediction of easy-to-heat or difficult-to-heat patients, and the dependency on various other individual parameters. We could show sufficient agreement between

  4. Crystallization in the systems Cu-I-HI-H2O and CuI-HI-H2O at elevated temperatures and pressures

    International Nuclear Information System (INIS)

    Popolitov, V.I.; Mininzon, Yu.M.

    1983-01-01

    Physicochemical investigation on synthesis and recrystallization of copper monoiodide monocrystals in the systems CU-I-HI-H 2 O and CuI-HI-W 2 O at high temperatures and pressures (200-300 deg and 50-160 atm) has been carried out. The optimum conditions for the growth of the Main tetrahedral facet (111) are clarified. The conditions are as follows: aqueous solution concentration Csub(HI)=32-35 mas.%, temperature 230-270 deg and external temperature gap 25-35 deg. Depending on synthesis conditions monocrystals CUI are prepared with different morphology of tetrahedral and cubooctahedral image. Kinetic regularities of CuI monocrystal preparation are presented and their physical properties, luminescence in particular, are studied

  5. An Interpreted Language and System for the Visualization of Unstructured Meshes

    Science.gov (United States)

    Moran, Patrick J.; Gerald-Yamasaki, Michael (Technical Monitor)

    1998-01-01

    We present an interpreted language and system supporting the visualization of unstructured meshes and the manipulation of shapes defined in terms of mesh subsets. The language features primitives inspired by geometric modeling, mathematical morphology and algebraic topology. The adaptation of the topology ideas to an interpreted environment, along with support for programming constructs such, as user function definition, provide a flexible system for analyzing a mesh and for calculating with shapes defined in terms of the mesh. We present results demonstrating some of the capabilities of the language, based on an implementation called the Shape Calculator, for tetrahedral meshes in R^3.

  6. Investigation of design method for air-conditioning system using CAE; CAE wo mochiita kucho haifu yosoku no ichikosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, M; Miyake, N; Takeuchi, T; Kori, I [Mitsubishi Motors Corp., Tokyo (Japan)

    1997-10-01

    Designing the air-conditioning system, the distributions of the flow rate and the temperature at each air outlet are important factors. This paper describes the prediction method using CFD (Computational Fluid Dynamics), which is based on the `{kappa}-{epsilon} turbulence model` and unstructured grid system. It is proved that conventional tetrahedral grid system gives adequate results for the flow rate prediction. However, it is also found that improvement is required for the thermal prediction. At the result, we suggested that the `prism mesh`, which has been developed for detailed calculation of the boundary layer properties, is essential for such the heat transfer problem. 4 refs., 13 figs.

  7. Electromagnetic reactions of few-body systems with the Lorentz integral transform method

    International Nuclear Information System (INIS)

    Leidemann, W.

    2007-01-01

    Various electromagnetic few-body break-up reactions into the many-body continuum are calculated microscopically with the Lorentz integral transform (LIT) method. For three- and four-body nuclei the nuclear Hamiltonian includes two- and three-nucleon forces, while semirealistic interactions are used in case of six- and seven-body systems. Comparisons with experimental data are discussed. In addition various interesting aspects of the 4 He photodisintegration are studied: investigation of a tetrahedrical symmetry of 4 He and a test of non-local nuclear force models via the induced two-body currents

  8. Synthesis and NMR characterization of SAPO-35 from non-aqueous systems using hexamethyleneimine template

    International Nuclear Information System (INIS)

    Venkatathri, N.

    2005-01-01

    SAPO-35 was synthesized using hexamethyleneimine template in non-aqueous systems. X-ray diffraction and scanning electron micrograph analysis shows the synthesized sample is pure and well crystalline. Presence of four stages (1.6%, 0.8%, 7.8% and 8.4%) of weight loss is observed by TG/DTA analysis. FT-IR analysis in the framework region shows the presence of tetrahedral T-O-T vibrations is similar to the other known aluminophosphate molecular sieves. FT-IR spectrum in the -OH region shows stretching vibrations at 3631, 3604 and 3580 cm -1 can be assigned to OH groups in bigger cages near S6R, in bigger cages near D6R and those actually confined inside the D6R, respectively. The spectra for the as-synthesized sample show a single symmetrical 27 Al MAS NMR line at δ = 36.26 indicating the presence of a single tetrahedral aluminium species. Where as 29 Si and 31 P MAS NMR shows the presence of two peaks in both at (-89.9 and -95.15 ppm) and (-34.01 and -40.45 ppm) due to the Si substitution of P present in two different locations in double 6 ring (D6R) and in single 6 ring (S6R). 27 Al 3Q-MAS NMR shows two peaks for environmentally different tetrahedral aluminium atoms. This is the first time we are showing such a fact which is not observable using ordinary MAS NMR

  9. Systems

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Papers in this session describe the concept of mined geologic disposal system and methods for ensuring that the system, when developed, will meet all technical requirements. Also presented in the session are analyses of system parameters, such as cost and nuclear criticality potential, as well as a technical analysis of a requirement that the system permit retrieval of the waste for some period of time. The final paper discusses studies under way to investigate technical alternatives or complements to the mined geologic disposal system. Titles of the presented papers are: (1) Waste Isolation System; (2) Waste Isolation Economics; (3) BWIP Technical Baseline; (4) Criticality Considerations in Geologic Disposal of High-Level Waste; (5) Retrieving Nuclear Wastes from Repository; (6) NWTS Programs for the Evaluation of Technical Alternatives or Complements to Mined Geologic Repositories - Purpose and Objectives

  10. systems

    Directory of Open Access Journals (Sweden)

    Alexander Leonessa

    2000-01-01

    Full Text Available A nonlinear robust control-system design framework predicated on a hierarchical switching controller architecture parameterized over a set of moving nominal system equilibria is developed. Specifically, using equilibria-dependent Lyapunov functions, a hierarchical nonlinear robust control strategy is developed that robustly stabilizes a given nonlinear system over a prescribed range of system uncertainty by robustly stabilizing a collection of nonlinear controlled uncertain subsystems. The robust switching nonlinear controller architecture is designed based on a generalized (lower semicontinuous Lyapunov function obtained by minimizing a potential function over a given switching set induced by the parameterized nominal system equilibria. The proposed framework robustly stabilizes a compact positively invariant set of a given nonlinear uncertain dynamical system with structured parametric uncertainty. Finally, the efficacy of the proposed approach is demonstrated on a jet engine propulsion control problem with uncertain pressure-flow map data.

  11. Global and Local Refinement Techniques Yielding Nonobtuse Tetrahedral Partitions

    Czech Academy of Sciences Publication Activity Database

    Korotov, S.; Křížek, Michal

    2005-01-01

    Roč. 50, č. 5 (2005), s. 1105-1113 ISSN 0898-1221 R&D Projects: GA AV ČR(CZ) IAA1019201 Institutional research plan: CEZ:AV0Z10190503 Keywords : elliptic equations * parabolic equations * discrete maximum principle Subject RIV: BA - General Mathematics Impact factor: 0.430, year: 2005

  12. Nonobtuse local tetrahedral refinements towards a polygonal face/interface

    Czech Academy of Sciences Publication Activity Database

    Korotov, S.; Křížek, Michal

    2011-01-01

    Roč. 24, č. 6 (2011), s. 817-821 ISSN 0893-9659 R&D Projects: GA AV ČR(CZ) IAA100190803 Institutional research plan: CEZ:AV0Z10190503 Keywords : finite element method * nonobtuse tetrahedron * local refinement * discrete maximum principle * boundary and interior layers * interface problem Subject RIV: BA - General Mathematics Impact factor: 1.371, year: 2011 http://www.sciencedirect.com/science/article/pii/S0893965910004726

  13. Surface Coverage in Wireless Sensor Networks Based on Delaunay Tetrahedralization

    International Nuclear Information System (INIS)

    Ribeiro, M G; Neves, L A; Zafalon, G F D; Valêncio, C; Pinto, A R; Nascimento, M Z

    2015-01-01

    In this work is presented a new method for sensor deployment on 3D surfaces. The method was structured on different steps. The first one aimed discretizes the relief of interest with Delaunay algorithm. The tetrahedra and relative values (spatial coordinates of each vertex and faces) were input to construction of 3D Voronoi diagram. Each circumcenter was calculated as a candidate position for a sensor node: the corresponding circular coverage area was calculated based on a radius r. The r value can be adjusted to simulate different kinds of sensors. The Dijkstra algorithm and a selection method were applied to eliminate candidate positions with overlapped coverage areas or beyond of surface of interest. Performance evaluations measures were defined using coverage area and communication as criteria. The results were relevant, once the mean coverage rate achieved on three different surfaces were among 91% and 100%

  14. Structure of inorganic phosphorus-nitrogen tetrahedral compounds

    International Nuclear Information System (INIS)

    Vitola, A.; Ronis, J.; Avotins, V.; Millers, T.

    1997-01-01

    The structure analysis of phosphorus-nitrogen compounds has shown the possibility of the P(O,N) 4 tetrahedra to form various kinds of structures. The wide spectrum of the properties determined by the diversity of structures marks the considerable promise to the future application of phosphorus-nitrogen compounds

  15. Tetrahedral Mesh Improvement Using Multi-face Retriangulation

    DEFF Research Database (Denmark)

    Misztal, Marek Krzysztof; Bærentzen, Jakob Andreas; Anton, François

    2009-01-01

    the algorithm is completely general with regard to quality criterion, we target improvement of the dihedral angle. The central idea in our algorithm is the introduction of a new local operation called multi-face retriangulation (MFRT) which supplements other known local operations. Like in many previous papers...

  16. Multi-phase Volume Segmentation with Tetrahedral Mesh

    DEFF Research Database (Denmark)

    Nguyen Trung, Tuan; Dahl, Vedrana Andersen; Bærentzen, Jakob Andreas

    Volume segmentation is efficient for reconstructing material structure, which is important for several analyses, e.g. simulation with finite element method, measurement of quantitative information like surface area, surface curvature, volume, etc. We are concerned about the representations of the 3......D volumes, which can be categorized into two groups: fixed voxel grids [1] and unstructured meshes [2]. Among these two representations, the voxel grids are more popular since manipulating a fixed grid is easier than an unstructured mesh, but they are less efficient for quantitative measurements....... In many cases, the voxel grids are converted to explicit meshes, however the conversion may reduce the accuracy of the segmentations, and the effort for meshing is also not trivial. On the other side, methods using unstructured meshes have difficulty in handling topology changes. To reduce the complexity...

  17. Estimation of Bulk modulus and microhardness of tetrahedral semiconductors

    International Nuclear Information System (INIS)

    Gorai, Sanjay Kumar

    2012-01-01

    A general empirical formula was found for calculating of bulk modulus (B) and microhardness (H) from electronegativity and principal quantum number of II-VI, III-V semiconductors. Constant C1, appearing the in the expression of bulk modulus and constants C2 and C3, appearing in the expression of microhardness and the exponent M have following values respectively The numerical values of C1,C2, C3 and M are respectively 206.6, 8.234, 1.291, -1.10 for II-VI 72.4, 31.87, 7.592, -0.95 for III-V semiconductors. Both electro-negativity and principal quantum number can effectively reflect on the chemical bonding behaviour of constituent atoms in these semiconductors. The calculated values of bulk modulus and microhardness are in good agreement with the reported values in the literature. Present study helps in designing novel semiconductor materials, and to further explore the mechanical properties of these semiconductors.

  18. Some notes on tetrahedrally closed spherical sets in Euclidean spaces

    Indian Academy of Sciences (India)

    47

    is a relation between these sets. P is called the point set, L the line set and I the incidence relation. A point-line geometry S = (P,L,I) is called a near polygon if every two distinct points are incident with at most one line and if for every point x and every line L, there exists a unique point on L that is nearest to x with respect to ...

  19. Kinetic and dynamic Delaunay tetrahedralizations in three dimensions

    Science.gov (United States)

    Schaller, Gernot; Meyer-Hermann, Michael

    2004-09-01

    We describe algorithms to implement fully dynamic and kinetic three-dimensional unconstrained Delaunay triangulations, where the time evolution of the triangulation is not only governed by moving vertices but also by a changing number of vertices. We use three-dimensional simplex flip algorithms, a stochastic visibility walk algorithm for point location and in addition, we propose a new simple method of deleting vertices from an existing three-dimensional Delaunay triangulation while maintaining the Delaunay property. As an example, we analyse the performance in various cases of practical relevance. The dual Dirichlet tessellation can be used to solve differential equations on an irregular grid, to define partitions in cell tissue simulations, for collision detection etc.

  20. Diffusion of interstitials in metallic systems, illustration of a complex study case: aluminum

    Science.gov (United States)

    David, Matthieu; Connétable, Damien

    2017-11-01

    While diffusion mechanisms of interstitial elements in fcc systems are generally well-known, especially in the case of H atoms, we show in this work that even in the case of a simple metallic system (aluminum), the diffusion of interstitials exhibits a wide variety of paths and mechanisms that depend on the specie. We used an approach based on first-principles calculations associated with kinetic Monte-Carlo simulations and a multi-state diffusion formalism to compute the diffusion coefficients of five interstitial elements: hydrogen, boron, carbon, nitrogen and oxygen. For instance, at the atomic scale, whilst we find that C atoms prefer to be located in octahedral sites (labeled o) rather than in tetrahedral positions (labeled t), we find one additional stable position in the lattice (M). The diffusion through these three stable positions are thus studied in detail. In the case of B atoms, for which the tetrahedral site is found unstable, the diffusion path is between o-o sites. Similarly, in the case of oxygen, t positions are found to be the only stable positions (o are unstable) and the path of migration, along t-t direction, is found through a twice degenerated asymmetric transition state. In the case of H and N atoms for which t and o sites are stable, we explain why the only path is along the t-o direction. Finally, we discuss explicit formulas to compute coefficients of diffusion of interstitials in fcc structures.

  1. NMR study of hydride systems

    International Nuclear Information System (INIS)

    Peretz, M.

    1980-02-01

    The hydrides of thorium (ThH 2 , Th 4 H 15 and Th 4 D 15 ) and the intermetallic compound system (Zr(Vsub(1-x)Cosub(x)) 2 and its hydrides were investigated using the nuclear magnetic resonance (NMR) technique. From the results for the thorium hydride samples it was concluded that the density of states at the Fermi level n(Esub(f)) is higher in Th 4 H 15 than in ThH 2 ; there is an indirect reaction between the protons and the d electrons belonging to the Th atoms in Th 4 H 15 ; n(E) has a sharp structure near Esub(f). It was also found that the hydrogen diffusion mechanism changes with temperature. From the results for the intermetallic compound system conclusions were drawn concerning variations in the electronic structure, which explain the behavior of the system. In hydrogen diffusion studies in several samples it was found that Co atoms slow the diffusion rate. Quadrupole spectra obtained at low temperatures show that the H atoms preferably occupy tetrahedral sites formed by three V atoms and one Z atom. (H.K.)

  2. Re4As6S3, a thio-spinel-related cluster system

    DEFF Research Database (Denmark)

    Besnard, Celine; Svensson, Christer; Ståhl, Kenny

    2003-01-01

    . The rhenium atoms form tetrahedral clusters linked via tetrahedral arsenic clusters to produce an NaCl-type arrangement. The oxidation state of rhenium is IV and the number of electrons shared by the rhenium atoms in the cluster is 12. The structure is based on an ordered defect thio-spinel A((1-x))B(2)X(4......) where the B-type atoms form tetrahedral clusters....

  3. SYSTEM

    Directory of Open Access Journals (Sweden)

    K. Swarnalatha

    2013-01-01

    Full Text Available Risk analysis of urban aquatic systems due to heavy metals turns significant due to their peculiar properties viz. persis tence, non-degradab ility, toxicity, and accumulation. Akkulam Veli (AV, an urba n tropical lake in south India is subjected to various environmental stresses due to multiple waste discharge, sand mining, developmental activities, tour ism related activitie s etc. Hence, a comprehensive approach is adopted for risk assessment using modified degree of contamination factor, toxicity units based on numerical sediment quality guidelines (SQGs, and potentialecological risk indices. The study revealed the presence of toxic metals such as Cr, C d, Pb and As and the lake is rated under ‘low ecological risk’ category.

  4. THE SYSTEMIC APPROACH TO TEACHING AND LEARNING:

    African Journals Online (AJOL)

    Rita Wilkinson

    central carbon. ... tetrahedral placement of the bonds around the central carbon. ... Remove the concealed lone pair on the central atom by retracting your opposable ... Sulfur dioxide: Central Atom Sulfur; Two bonding pairs and one lone pair.

  5. Quatenary Na//F, Cl, CO3, MoO4 system

    International Nuclear Information System (INIS)

    Kochkarov, Zh.A.; Lok''yaeva, S.M.; Shurdumov, G.K.; Gasanaliev, A.M.; Trunin, A.S.

    1999-01-01

    Perspective in applied respect quatenary system (NaF) 2 -(NaCl)-Na 2 CO 3 -Na 2 MoO 4 being element of narrowing of more complex six-membered mutual Na//F, Cl, CO 3 , MoO 4 (WO 4 ) system is investigated by differential thermal analysis with the use of projection-thermographic method for the first time. Crystallization tree of Na//F, Cl, CO 3 , MoO 4 system is established. It is shown that this system by tetrahedrating (NaF) 2 -Na 2 CO 3 -Na 3 ClMoO 4 section is triangulated on two stable system: (NaF) 2 -Na 3 ClMoO 4 -Na 2 CO 3 -(NaCl) 2 and (NaF) 2 -Na 3 ClMoO 4 -Na 2 CO 3 -Na 2 MoO 4 . Phase single units are determined too. Coordinates of desired quatenary nonvariant points are calculated on analytical models of surfaces by mutual crystallization of two phases and are refined by differential thermal analysis [ru

  6. Toward multiscale modelings of grain-fluid systems

    Science.gov (United States)

    Chareyre, Bruno; Yuan, Chao; Montella, Eduard P.; Salager, Simon

    2017-06-01

    Computationally efficient methods have been developed for simulating partially saturated granular materials in the pendular regime. In contrast, one hardly avoid expensive direct resolutions of 2-phase fluid dynamics problem for mixed pendular-funicular situations or even saturated regimes. Following previous developments for single-phase flow, a pore-network approach of the coupling problems is described. The geometry and movements of phases and interfaces are described on the basis of a tetrahedrization of the pore space, introducing elementary objects such as bridge, meniscus, pore body and pore throat, together with local rules of evolution. As firmly established local rules are still missing on some aspects (entry capillary pressure and pore-scale pressure-saturation relations, forces on the grains, or kinetics of transfers in mixed situations) a multi-scale numerical framework is introduced, enhancing the pore-network approach with the help of direct simulations. Small subsets of a granular system are extracted, in which multiphase scenario are solved using the Lattice-Boltzman method (LBM). In turns, a global problem is assembled and solved at the network scale, as illustrated by a simulated primary drainage.

  7. Shells, orbit bifurcations, and symmetry restorations in Fermi systems

    Energy Technology Data Exchange (ETDEWEB)

    Magner, A. G., E-mail: magner@kinr.kiev.ua; Koliesnik, M. V. [NASU, Institute for Nuclear Research (Ukraine); Arita, K. [Nagoya Institute of Technology, Department of Physics (Japan)

    2016-11-15

    The periodic-orbit theory based on the improved stationary-phase method within the phase-space path integral approach is presented for the semiclassical description of the nuclear shell structure, concerning themain topics of the fruitful activity ofV.G. Soloviev. We apply this theory to study bifurcations and symmetry breaking phenomena in a radial power-law potential which is close to the realistic Woods–Saxon one up to about the Fermi energy. Using the realistic parametrization of nuclear shapes we explain the origin of the double-humped fission barrier and the asymmetry in the fission isomer shapes by the bifurcations of periodic orbits. The semiclassical origin of the oblate–prolate shape asymmetry and tetrahedral shapes is also suggested within the improved periodic-orbit approach. The enhancement of shell structures at some surface diffuseness and deformation parameters of such shapes are explained by existence of the simple local bifurcations and new non-local bridge-orbit bifurcations in integrable and partially integrable Fermi-systems. We obtained good agreement between the semiclassical and quantum shell-structure components of the level density and energy for several surface diffuseness and deformation parameters of the potentials, including their symmetry breaking and bifurcation values.

  8. Photoluminescence of the Mg2Al4Si5O18-Al2O3-MgAl2O4-SiO2 ceramic system containing Fe3+ and Cr3+ as impurity ions

    Science.gov (United States)

    Sosman, L. P.; López, A.; Pedro, S. S.; Papa, A. R. R.

    2018-02-01

    This work presents the results of photoluminescence, excitation and radiative decay time for a ceramic system containing Mg2Al4Si5O18-Al2O3-MgAl2O4-SiO2 with Fe3+ and Cr3+ as impurity ions. Emission data were obtained using several excitation wavelengths and the excitation data were acquired for the most intense emission bands. The optical results were analyzed according to the Tanabe-Sugano (TS) theory from which the crystalline field parameter Dq and Racah parameters B and C were obtained for the Fe3+ and Cr3+ sites. The results indicate that the Fe3+ and Cr3+ ions occupy tetrahedral and octahedral sites, respectively. The emission from Fe3+ and Cr3+ ions causes an intense and broad band ranging between 350 nm and 850 nm, showing that this material is a potential tunable radiation source at room temperature.

  9. Weakened acute type condition for tetrahedral triangulations and the discrete maximum principle

    Czech Academy of Sciences Publication Activity Database

    Korotov, S.; Křížek, Michal; Neittaanmäki, P.

    2001-01-01

    Roč. 70, č. 233 (2001), s. 107-119 ISSN 0025-5718 Grant - others:GA Academy of Finland(FI) 752205 Institutional research plan: CEZ:AV0Z1019905 Subject RIV: BA - General Mathematics Impact factor: 0.990, year: 2001

  10. Earliest stage of the tetrahedral nanochannel formation in cubosome particles from unilamellar nanovesicles

    Czech Academy of Sciences Publication Activity Database

    Angelov, Borislav; Angelova, A.; Garamus, V. M.; Drechsler, M.; Willumeit, R.; Mutafchieva, R.; Štěpánek, Petr; Lesieur, S.

    Roč. 28, č. 48 ( 2012 ), s. 16647-16655 ISSN 0743-7463 R&D Projects: GA ČR GAP208/10/1600 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : cryoTEM electron microscopy * SAXS * soft matter Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.187, year: 2012

  11. Electron doping through lithium intercalation to interstitial channels in tetrahedrally bonded SiC

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Yuki [Department of Applied Physics, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Center for Computational Materials, Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, Texas 78712 (United States); Oshiyama, Atsushi [Department of Applied Physics, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2015-11-07

    We report on first-principles calculations that clarify the effect of lithium atom intercalation into zinc blende 3C-silicon carbide (3C-SiC) on electronic and structural properties. Lithium atoms inside 3C-SiC are found to donate electrons to 3C-SiC that is an indication of a new way of electron doping through the intercalation. The electrons doped into the conduction band interact with lithium cations and reduce the band spacing between the original valence and conduction bands. We have also found that a silicon monovacancy in 3C-SiC promotes the lithium intercalation, showing that the vacancy generation makes SiC as a possible anode material for lithium-ion battery.

  12. Global Time Tomography of Finite Frequency Waves with Optimized Tetrahedral Grids.

    Science.gov (United States)

    Montelli, R.; Montelli, R.; Nolet, G.; Dahlen, F. A.; Masters, G.; Hung, S.

    2001-12-01

    Besides true velocity heterogeneities, tomographic images reflect the effect of data errors, model parametrization, linearization, uncertainties involved with the solution of the forward problem and the greatly inadequate sampling of the earth by seismic rays. These influences cannot be easily separated and often produce artefacts in the final image with amplitudes comparable to those of the velocity heterogeneities. In practice, the tomographer uses some form of damping of the ill-resolved aspects of the model to get a unique solution and reduce the influence of the errors. However damping is not fully adequate, and may reveal a strong influence of the ray path coverage in tomographic images. If some cells are ill determinated regularization techniques may lead to heterogeneity because these cells are damped towards zero. Thus we want a uniform resolution of the parameters in our model. This can be obtained by using an irregular grid with variable length scales. We have introduced an irregular parametrization of the velocity structure by using a Delaunay triangulation. Extensively work on error analysis of tomographic images together with mesh optimization has shown that both resolution and ray density can provide the critical informations needed to re-design grids. However, criteria based on resolution are preferred in the presence of narrow ray beams coming from the same direction. This can be understood if we realise that resolution is not only determined by the number of rays crossing a region, but also by their azimutal coverage. We shall discuss various strategies for grid optimization. In general the computation of the travel times is restricted to ray theory, the infinite frequency approximation of the elastodynamic equation of motion. This simplifies the mathematic and is therefore widely applied in seismic tomography. But ray theory does not account for scattering, wavefront healing and other diffraction effects that render the traveltime of a finite frequency seismic waves sensitive to three-dimensional structure off rays. Dahlen et al (2000) used the Born approximation to find a double-ray sum representation of the 3D Fréchet kernel. Destructive interference among adjacent frequencies in the broad-band pulse renders a cross-correlation traveltime measurement sensitive only to the wave speed in a hollow banana-shaped region surrounding the unperturbed geometrical ray. We combined the banana-doughnut kernel with the formalism for the adaptive parametrization based on resolution criterion for a long-period body wave data set. Both absolute and differential times are computed using cross-correlation of each observed arrival with a synthetic pulse contructed by convolving the impulse response of the instrument at Albuquerque (ANMO) and an attenuation operator for the preliminary reference earth model (PREM). We shall present some first results illustrating the effects of using banana-doughnut Fréchet kernels instead of ray theory on the contruction of optimized Delaunay meshes.

  13. Erasing no-man's land by thermodynamically stabilizing the liquid-liquid transition in tetrahedral particles

    NARCIS (Netherlands)

    Smallenburg, Frank; Filion, Laura|info:eu-repo/dai/nl/326823484; Sciortino, Francesco

    2014-01-01

    One of the most controversial hypotheses for explaining the origin of the thermodynamic anomalies characterizing liquid water postulates the presence of a metastable second-order liquid-liquid critical point located in the 'no-man's land'. In this scenario, two liquids with distinct local structure

  14. Configuring PSx tetrahedral clusters in Li-excess Li7P3S11 solid electrolyte

    Directory of Open Access Journals (Sweden)

    Wo Dum Jung

    2018-04-01

    Full Text Available We demonstrate that the Li-ion conductivity can be improved by adding a certain amount of Li (x = 0.25–0.5 as a charge carrier to the composition of glass-ceramic Li7+xP3S11. Structural analysis clarified that the structural changes caused by the ratio of ortho-thiophosphate tetrahedra PS43− and pyro-thiophosphate ditetrahedra P2S74− affect the Li-ion conductivity. The ratio of PS43− and P2S74− varies depending on x and the highest Li-ion conductivity (2.5 × 10−3 S cm−1 at x = 0.25. All-solid-state LiNi0.8Co0.15Al0.05O2/Li7.25P3S11/In-metal cell exhibits the discharge capacity of 106.2 mAh g−1. This ion conduction enhancement from excess Li is expected to contribute to the future design of sulfide-type electrolytes.

  15. Strongly regular family of boundary-fitted tetrahedral meshes of bounded C^2 domains

    Czech Academy of Sciences Publication Activity Database

    Hošek, Radim

    2016-01-01

    Roč. 61, č. 3 (2016), s. 233-251 ISSN 0862-7940 EU Projects: European Commission(XE) 320078 - MATHEF Institutional support: RVO:67985840 Keywords : boundary fitted mesh * strongly regular family * Sommerville tetrahedron Subject RIV: BA - General Mathematics Impact factor: 0.618, year: 2016 http://hdl.handle.net/10338.dmlcz/145699

  16. Analysis of rotation-vibration relative equilibria on the example of a tetrahedral four atom molecule

    NARCIS (Netherlands)

    Efstathiou, K; Sadovskii, DA; Zhilinskii, BI

    2004-01-01

    We study relative equilibria ( RE) of a nonrigid molecule, which vibrates about a well-defined equilibrium configuration and rotates as a whole. Our analysis unifies the theory of rotational and vibrational RE. We rely on the detailed study of the symmetry group action on the initial and reduced

  17. Finite element method for solving Kohn-Sham equations based on self-adaptive tetrahedral mesh

    International Nuclear Information System (INIS)

    Zhang Dier; Shen Lihua; Zhou Aihui; Gong Xingao

    2008-01-01

    A finite element (FE) method with self-adaptive mesh-refinement technique is developed for solving the density functional Kohn-Sham equations. The FE method adopts local piecewise polynomials basis functions, which produces sparsely structured matrices of Hamiltonian. The method is well suitable for parallel implementation without using Fourier transform. In addition, the self-adaptive mesh-refinement technique can control the computational accuracy and efficiency with optimal mesh density in different regions

  18. Orientational order and rotational relaxation in the plastic crystal phase of tetrahedral molecules.

    Science.gov (United States)

    Rey, Rossend

    2008-01-17

    A methodology recently introduced to describe orientational order in liquid carbon tetrachloride is extended to the plastic crystal phase of XY4 molecules. The notion that liquid and plastic crystal phases are germane regarding orientational order is confirmed for short intermolecular distances but is seen to fail beyond, as long range orientational correlations are found for the simulated solid phase. It is argued that, if real, such a phenomenon may not to be accessible with direct (diffraction) methods due to the high molecular symmetry. This behavior is linked to the existence of preferential orientation with respect to the fcc crystalline network defined by the centers of mass. It is found that the dominant class accounts, at most, for one-third of all configurations, with a feeble dependence on temperature. Finally, the issue of rotational relaxation is also addressed, with an excellent agreement with experimental measures. It is shown that relaxation is nonhomogeneous in the picosecond range, with a slight dispersion of decay times depending on the initial orientational class. The results reported mainly correspond to neopentane over a wide temperature range, although results for carbon tetrachloride are included, as well.

  19. Accurate reaction-diffusion operator splitting on tetrahedral meshes for parallel stochastic molecular simulations

    Energy Technology Data Exchange (ETDEWEB)

    Hepburn, I.; De Schutter, E., E-mail: erik@oist.jp [Computational Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904 0495 (Japan); Theoretical Neurobiology & Neuroengineering, University of Antwerp, Antwerp 2610 (Belgium); Chen, W. [Computational Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904 0495 (Japan)

    2016-08-07

    Spatial stochastic molecular simulations in biology are limited by the intense computation required to track molecules in space either in a discrete time or discrete space framework, which has led to the development of parallel methods that can take advantage of the power of modern supercomputers in recent years. We systematically test suggested components of stochastic reaction-diffusion operator splitting in the literature and discuss their effects on accuracy. We introduce an operator splitting implementation for irregular meshes that enhances accuracy with minimal performance cost. We test a range of models in small-scale MPI simulations from simple diffusion models to realistic biological models and find that multi-dimensional geometry partitioning is an important consideration for optimum performance. We demonstrate performance gains of 1-3 orders of magnitude in the parallel implementation, with peak performance strongly dependent on model specification.

  20. Gas-liquid phase coexistence in a tetrahedral patchy particle model

    International Nuclear Information System (INIS)

    Romano, Flavio; Tartaglia, Piero; Sciortino, Francesco

    2007-01-01

    We evaluate the location of the gas-liquid coexistence line and of the associated critical point for the primitive model for water (PMW), introduced by Kolafa and Nezbeda (1987 Mol. Phys. 61 161). Besides being a simple model for a molecular network forming liquid, the PMW is representative of patchy proteins and novel colloidal particles interacting with localized directional short-range attractions. We show that the gas-liquid phase separation is metastable, i.e. it takes place in the region of the phase diagram where the crystal phase is thermodynamically favoured, as in the case of particles interacting via short-range attractive spherical potentials. We do not observe crystallization close to the critical point. The region of gas-liquid instability of this patchy model is significantly reduced as compared to that from equivalent models of spherically interacting particles, confirming the possibility of observing kinetic arrest in a homogeneous sample driven by bonding as opposed to packing. (fast track communication)

  1. Clinical evaluation and verification of the hyperthermia treatment planning system hyperplan

    International Nuclear Information System (INIS)

    Gellermann, Johanna; Wust, Peter; Stalling, Dether; Seebass, Martin; Nadobny, Jacek; Beck, Rudolf; Hege, Hans-Christian; Deuflhard, Peter; Felix, Roland

    2000-01-01

    Purpose: A prototype of the hyperthermia treatment planning system (HTPS) HyperPlan for the SIGMA-60 applicator (BSD Medical Corp., Salt Lake City, Utah, USA) has been evaluated with respect to clinical practicability and correctness. Materials and Methods: HyperPlan modules extract tissue boundaries from computed tomography (CT) images to generate regular and tetrahedral grids as patient models, to calculate electric field (E-field) distributions, and to visualize three-dimensional data sets. The finite difference time-domain (FDTD) method is applied to calculate the specific absorption rate (SAR) inside the patient. Temperature distributions are calculated by a finite-element code and can be optimized. HyperPlan was tested on 6 patients with pelvic tumors. For verification, measured SAR values were compared with calculated SAR values. Furthermore, intracorporeal E-field scans were performed and compared with calculated profiles. Results: The HTPS can be applied under clinical conditions. Measured absolute SAR (in W/kg), as well as relative E-field scans, correlated well with calculated values (±20%) using the contour-based FDTD method. Values calculated by applying the FDTD method directly on the voxel (CT) grid, were less well correlated with measured data. Conclusion: The HyperPlan system proved to be clinically feasible, and the results were quantitatively and qualitatively verified for the contour-based FDTD method

  2. Production of thin carbon stripper foils using heated-substrates in a cathodic arc deposition system

    International Nuclear Information System (INIS)

    Merchant, A.R.; Lobanov, N.; Elliman, R.G.; Ophel, T.R.; Rode, A.; Weisser, D.C.; Turkentine, R.B.

    1998-01-01

    The lifetime of carbon stripper foil can have a marked impact on the successful running of a beam line. Standard techniques for production of carbon stripper foils include evaporation of carbon (ec) and laser-pulsed ablation (Ipa). Recent work by a using Ipa has been successful in substantially increasing the lifetime of a very thin foil. The suspected mechanism for the increased lifetime of the foil is that the amorphous carbon foil is density-matched to that of graphite (around 2.26g/cc). In this work, we attempt to reproduce this result by producing carbon stripper foils with a mass-density similar to graphite using a cathodic arc deposition system. The cathodic arc is well known for the production of tetrahedral amorphous carbon: a high density, high stress form of carbon with over 90% sp 3 -like bonds; to reduce the density of the carbon and promote more graphitic structure, a high bias was initially attempted but this proved unsuccessful. Another method is to use a heated-substrate holder to reduce compressive stress within the deposited film. The performance of the density-matched carbon stripper foils and the implications for future production of high-quality carbon stripper foils in our laboratory will be discussed. (authors)

  3. Direct-current cathodic vacuum arc system with magnetic-field mechanism for plasma stabilization.

    Science.gov (United States)

    Zhang, H-S; Komvopoulos, K

    2008-07-01

    Filtered cathodic vacuum arc (FCVA) deposition is characterized by plasma beam directionality, plasma energy adjustment via substrate biasing, macroparticle filtering, and independent substrate temperature control. Between the two modes of FCVA deposition, namely, direct current (dc) and pulsed arc, the dc mode yields higher deposition rates than the pulsed mode. However, maintaining the dc arc discharge is challenging because of its inherent plasma instabilities. A system generating a special configuration of magnetic field that stabilizes the dc arc discharge during film deposition is presented. This magnetic field is also part of the out-of-plane magnetic filter used to focus the plasma beam and prevent macroparticle film contamination. The efficiency of the plasma-stabilizing magnetic-field mechanism is demonstrated by the deposition of amorphous carbon (a-C) films exhibiting significantly high hardness and tetrahedral carbon hybridization (sp3) contents higher than 70%. Such high-quality films cannot be produced by dc arc deposition without the plasma-stabilizing mechanism presented in this study.

  4. Direct-current cathodic vacuum arc system with magnetic-field mechanism for plasma stabilization

    International Nuclear Information System (INIS)

    Zhang, H.-S.; Komvopoulos, K.

    2008-01-01

    Filtered cathodic vacuum arc (FCVA) deposition is characterized by plasma beam directionality, plasma energy adjustment via substrate biasing, macroparticle filtering, and independent substrate temperature control. Between the two modes of FCVA deposition, namely, direct current (dc) and pulsed arc, the dc mode yields higher deposition rates than the pulsed mode. However, maintaining the dc arc discharge is challenging because of its inherent plasma instabilities. A system generating a special configuration of magnetic field that stabilizes the dc arc discharge during film deposition is presented. This magnetic field is also part of the out-of-plane magnetic filter used to focus the plasma beam and prevent macroparticle film contamination. The efficiency of the plasma-stabilizing magnetic-field mechanism is demonstrated by the deposition of amorphous carbon (a-C) films exhibiting significantly high hardness and tetrahedral carbon hybridization (sp 3 ) contents higher than 70%. Such high-quality films cannot be produced by dc arc deposition without the plasma-stabilizing mechanism presented in this study

  5. Order-disorder transition and electrical conductivity of the brownmillerite solid-solutions system Ba2(In, M)2O5 (M=Ga, Al)

    International Nuclear Information System (INIS)

    Yamamura, Hiroshi; Hamazaki, Hirohumi; Kakinuma, Katsuyoshi; Mori, Toshiyuki; Haneda, Hajime

    1999-01-01

    The brownmillerite solid-solution systems Ba 2 (In 1-x M x ) 2 O 5 (M=Ga, Al) were investigated by means of high-temperature X-ray diffraction (XRD), dilatometry, and electrical-conductivity measurements. XRD showed that the Ba 2 (In 1-x Ga x ) 2 O 5 system had orthorhombic symmetry in the composition range 0.0≤x≤0.2 and cubic symmetry in the range 0.3≤x. The Al system also changed to cubic symmetry from orthorhombic symmetry in the range 0.2≤x. While the orthorhombic phase showed an order-disorder transition in the electrical conductivity measurements, the transition temperature decreased with increasing the M content. The order-disorder transition temperature and the crystal-structure transition temperature were very different. Such a transition was not observed in the cubic phases, and their electrical conductivity were fairly low compared to those of the disordered cubic phase after the transition due to the heating process. These phenomena are discussed in terms of disordering of the tetrahedral site in the brownmillerite structure, which is occupied by the smaller Ga 3+ or Al 3+ rather than ny In 3+

  6. Computational Investigation of a Boundary-Layer Ingesting Propulsion System for the Common Research Model

    Science.gov (United States)

    Blumenthal, Brennan T.; Elmiligui, Alaa; Geiselhart, Karl A.; Campbell, Richard L.; Maughmer, Mark D.; Schmitz, Sven

    2016-01-01

    The present paper examines potential propulsive and aerodynamic benefits of integrating a Boundary-Layer Ingestion (BLI) propulsion system into a typical commercial aircraft using the Common Research Model (CRM) geometry and the NASA Tetrahedral Unstructured Software System (TetrUSS). The Numerical Propulsion System Simulation (NPSS) environment is used to generate engine conditions for CFD analysis. Improvements to the BLI geometry are made using the Constrained Direct Iterative Surface Curvature (CDISC) design method. Previous studies have shown reductions of up to 25% in terms of propulsive power required for cruise for other axisymmetric geometries using the BLI concept. An analysis of engine power requirements, drag, and lift coefficients using the baseline and BLI geometries coupled with the NPSS model are shown. Potential benefits of the BLI system relating to cruise propulsive power are quantified using a power balance method, and a comparison to the baseline case is made. Iterations of the BLI geometric design are shown and any improvements between subsequent BLI designs presented. Simulations are conducted for a cruise flight condition of Mach 0.85 at an altitude of 38,500 feet and an angle of attack of 2 deg for all geometries. A comparison between available wind tunnel data, previous computational results, and the original CRM model is presented for model verification purposes along with full results for BLI power savings. Results indicate a 14.4% reduction in engine power requirements at cruise for the BLI configuration over the baseline geometry. Minor shaping of the aft portion of the fuselage using CDISC has been shown to increase the benefit from Boundary-Layer Ingestion further, resulting in a 15.6% reduction in power requirements for cruise as well as a drag reduction of eighteen counts over the baseline geometry.

  7. Computational Investigation of a Boundary-Layer Ingestion Propulsion System for the Common Research Model

    Science.gov (United States)

    Blumenthal, Brennan

    2016-01-01

    This thesis will examine potential propulsive and aerodynamic benefits of integrating a boundary-layer ingestion (BLI) propulsion system with a typical commercial aircraft using the Common Research Model geometry and the NASA Tetrahedral Unstructured Software System (TetrUSS). The Numerical Propulsion System Simulation (NPSS) environment will be used to generate engine conditions for CFD analysis. Improvements to the BLI geometry will be made using the Constrained Direct Iterative Surface Curvature (CDISC) design method. Previous studies have shown reductions of up to 25% in terms of propulsive power required for cruise for other axisymmetric geometries using the BLI concept. An analysis of engine power requirements, drag, and lift coefficients using the baseline and BLI geometries coupled with the NPSS model are shown. Potential benefits of the BLI system relating to cruise propulsive power are quantified using a power balance method and a comparison to the baseline case is made. Iterations of the BLI geometric design are shown and any improvements between subsequent BLI designs presented. Simulations are conducted for a cruise flight condition of Mach 0.85 at an altitude of 38,500 feet and an angle of attack of 2deg for all geometries. A comparison between available wind tunnel data, previous computational results, and the original CRM model is presented for model verification purposes along with full results for BLI power savings. Results indicate a 14.3% reduction in engine power requirements at cruise for the BLI configuration over the baseline geometry. Minor shaping of the aft portion of the fuselage using CDISC has been shown to increase the benefit from boundary-layer ingestion further, resulting in a 15.6% reduction in power requirements for cruise as well as a drag reduction of eighteen counts over the baseline geometry.

  8. System Budgets

    DEFF Research Database (Denmark)

    Jeppesen, Palle

    1996-01-01

    The lecture note is aimed at introducing system budgets for optical communication systems. It treats optical fiber communication systems (six generations), system design, bandwidth effects, other system impairments and optical amplifiers.......The lecture note is aimed at introducing system budgets for optical communication systems. It treats optical fiber communication systems (six generations), system design, bandwidth effects, other system impairments and optical amplifiers....

  9. The element level time domain (ELTD) method for the analysis of nano-optical systems: I. Nondispersive media

    Science.gov (United States)

    Fallahi, Arya; Oswald, Benedikt; Leidenberger, Patrick

    2012-04-01

    We study a 3-dimensional, dual-field, fully explicit method for the solution of Maxwell's equations in the time domain on unstructured, tetrahedral grids. The algorithm uses the element level time domain (ELTD) discretization of the electric and magnetic vector wave equations. In particular, the suitability of the method for the numerical analysis of nanometer structured systems in the optical region of the electromagnetic spectrum is investigated. The details of the theory and its implementation as a computer code are introduced and its convergence behavior as well as conditions for stable time domain integration is examined. Here, we restrict ourselves to non-dispersive dielectric material properties since dielectric dispersion will be treated in a subsequent paper. Analytically solvable problems are analyzed in order to benchmark the method. Eventually, a dielectric microlens is considered to demonstrate the potential of the method. A flexible method of 2nd order accuracy is obtained that is applicable to a wide range of nano-optical configurations and can be a serious competitor to more conventional finite difference time domain schemes which operate only on hexahedral grids. The ELTD scheme can resolve geometries with a wide span of characteristic length scales and with the appropriate level of detail, using small tetrahedra where delicate, physically relevant details must be modeled.

  10. Raman, FTIR, thermal and optical properties of TeO2-Nb2O5-B2O3-V2O5 quaternary glass system

    Directory of Open Access Journals (Sweden)

    Swapna

    2017-07-01

    Full Text Available A series of quaternary glass systems with the composition 79TeO2-(20−xNb2O5-xB2O3-1V2O5 was prepared using the melt quench technique. Such studies as optical absorption, Raman, FTIR spectroscopy, EPR and DSC were carried out on the glass system. The physical properties, such as density (ρ and molar volume (VM, were determined. The Urbach energy (ΔE, optical band gap (Eopt, optical basicity (Λ, refractive index (n and electron polarizability (α of the glasses were determined from optical absorption data. Spin-Hamiltonian parameters of VO2+ ions were calculated from the EPR data. With the gradual substitution of B2O3 at the expense of Nb2O5, the density and optical band gap of the glasses decreased, and the electronic polarizability increased. EPR spectra revealed that VO2+ occupies an octahedral site with tetrahedral compression. Spin-Hamiltonian parameters g|| and g⊥ increased as B2O3 content increased in the glass. The glass transition temperature (Tg also decreased as the B2O3 content in the glass increased.

  11. Modelling of 3D fractured geological systems - technique and application

    Science.gov (United States)

    Cacace, M.; Scheck-Wenderoth, M.; Cherubini, Y.; Kaiser, B. O.; Bloecher, G.

    2011-12-01

    All rocks in the earth's crust are fractured to some extent. Faults and fractures are important in different scientific and industry fields comprising engineering, geotechnical and hydrogeological applications. Many petroleum, gas and geothermal and water supply reservoirs form in faulted and fractured geological systems. Additionally, faults and fractures may control the transport of chemical contaminants into and through the subsurface. Depending on their origin and orientation with respect to the recent and palaeo stress field as well as on the overall kinematics of chemical processes occurring within them, faults and fractures can act either as hydraulic conductors providing preferential pathways for fluid to flow or as barriers preventing flow across them. The main challenge in modelling processes occurring in fractured rocks is related to the way of describing the heterogeneities of such geological systems. Flow paths are controlled by the geometry of faults and their open void space. To correctly simulate these processes an adequate 3D mesh is a basic requirement. Unfortunately, the representation of realistic 3D geological environments is limited by the complexity of embedded fracture networks often resulting in oversimplified models of the natural system. A technical description of an improved method to integrate generic dipping structures (representing faults and fractures) into a 3D porous medium is out forward. The automated mesh generation algorithm is composed of various existing routines from computational geometry (e.g. 2D-3D projection, interpolation, intersection, convex hull calculation) and meshing (e.g. triangulation in 2D and tetrahedralization in 3D). All routines have been combined in an automated software framework and the robustness of the approach has been tested and verified. These techniques and methods can be applied for fractured porous media including fault systems and therefore found wide applications in different geo-energy related

  12. Ventilation systems

    International Nuclear Information System (INIS)

    Gossler

    1980-01-01

    The present paper deals with - controlled area ventilation systems - ventilation systems for switchgear-building and control-room - other ventilation systems for safety equipments - service systems for ventilation systems. (orig./RW)

  13. Structural and electrical phase transitions in the [(C2H5)4N]2ZnI3.86Cl0.14 system

    Science.gov (United States)

    Rhouma, Najla Mahbouli; Rayes, Ali; Mezzadri, Francesco; Delmonte, Davide; Cabassi, Riccardo; Calestani, Gianluca; Loukil, Mohamed

    2017-12-01

    The organic-inorganic hybrid non-centrosymmetric material [(C2H5)4N]2ZnI3.86Cl0.14 has been studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC), dielectric and transport measurements. In analogy with the corresponding tetraiodo-zincate analogue, the material crystallizes at room temperature in the tetragonal system, space group P 4 ̅ 21m (No. 113), with lattice parameters a = 13.743(6) and c = 14.785(10) Å. DSC and XRD characterizations pointed out the occurrence of two phases transitions, one of second order at about 290 K and the other of the first order at T = 451 K. The former is related to an electrical transition from insulating to thermally activated transport mechanism displaying clear hints of ionic conduction, the latter leads to a phase showing the typical features of plastic crystals in its powder XRD pattern. The pattern was indexed by an orthorhombic cell, a = 15.724(1), b = 17.907(1) and c = 10.585(1) Å, and a reliable model was found and refined in the Pna21 space group. The model consists of ordered tetrahedral ZnCl42- units intercalated by fully disordered tetraethylammonium cations.

  14. Spectroscopic and optical properties of the VO2+ ion doped TeO2-TiO2-ZnO-Nb2O5 glass system

    Science.gov (United States)

    Swapna; Upender, G.; Sreenivasulu, V.; Prasad, M.

    2016-04-01

    Studies such as optical absorption, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Electron paramagnetic resonance (EPR) spectroscopy and Differential scanning calorimetry (DSC) were carried out on VO2+ ion doped TeO2-TiO2-ZnO-Nb2O5 glass system. Raman and FTIR spectra of the glasses revealed the presence of [TeO3], [TeO4] and [NbO6] structural units in the glass network. The Urbach energy (Δ E), cut-off wavelength (λ c ), optical band gap ( E opt ), optical basicity (Λ) and electron polarizability ( α) of the glasses were determined from optical absorption studies. The density ( ρ), molar volume ( V m ), oxygen molar volume ( V o ) and refractive index ( n) were also measured. Spin-Hamiltonian parameters were calculated from the EPR studies. When Nb2O5 was increased at the expense of ZnO, the density, optical band gap and Urbach energy of the glasses increased, and the electronic polarizability and optical basicity decreased. The EPR spectra clearly showed that vanadium was in the glass as VO2+ and occupied octahedral sites with tetrahedral compression. Spin-Hamiltonian parameters g‖ and g⊥ decreased as Nb2O5 content increased in the glass. The glass transition temperature ( T g ) also increased with increasing Nb2O5 content in the glass.

  15. Embedded Systems

    Indian Academy of Sciences (India)

    Embedded system, micro-con- troller ... Embedded systems differ from general purpose computers in many ... Low cost: As embedded systems are extensively used in con- .... operating systems for the desktop computers where scheduling.

  16. Thermal systems; Systemes thermiques

    Energy Technology Data Exchange (ETDEWEB)

    Lalot, S. [Valenciennes Univ. et du Hainaut Cambresis, LME, 59 (France); Lecoeuche, S. [Ecole des Mines de Douai, Dept. GIP, 59 - Douai (France)]|[Lille Univ. des Sciences et Technologies, 59 - Villeneuve d' Ascq (France); Ahmad, M.; Sallee, H.; Quenard, D. [CSTB, 38 - Saint Martin d' Heres (France); Bontemps, A. [Universite Joseph Fourier, LEGI/GRETh, 38 - Grenoble (France); Gascoin, N.; Gillard, P.; Bernard, S. [Laboratoire d' Energetique, Explosion, Structure, 18 - Bourges (France); Gascoin, N.; Toure, Y. [Laboratoire Vision et Robotique, 18 - Bourges (France); Daniau, E.; Bouchez, M. [MBDA, 18 - Bourges (France); Dobrovicescu, A.; Stanciu, D. [Bucarest Univ. Polytechnique, Faculte de Genie Mecanique (Romania); Stoian, M. [Reims Univ. Champagne Ardenne, Faculte des Sciences, UTAP/LTM, 51 (France); Bruch, A.; Fourmigue, J.F.; Colasson, S. [CEA Grenoble, Lab. Greth, 38 (France); Bontemps, A. [Universite Joseph Fourier, LEGI/GRETh, 38 - Grenoble (France); Voicu, I.; Mare, T.; Miriel, J. [Institut National des Sciences Appliquees (INSA), LGCGM, IUT, 35 - Rennes (France); Galanis, N. [Sherbrooke Univ., Genie Mecanique, QC (Canada); Nemer, M.; Clodic, D. [Ecole des Mines de Paris, Centre Energetique et Procedes, 75 (France); Lasbet, Y.; Auvity, B.; Castelain, C.; Peerhossaini, H. [Nantes Univ., Ecole Polytechnique, Lab. de Thermocinetiquede Nantes, UMR-CNRS 6607, 44 (France)

    2005-07-01

    This session about thermal systems gathers 26 articles dealing with: neural model of a compact heat exchanger; experimental study and numerical simulation of the thermal behaviour of test-cells with walls made of a combination of phase change materials and super-insulating materials; hydraulic and thermal modeling of a supercritical fluid with pyrolysis inside a heated channel: pre-dimensioning of an experimental study; energy analysis of the heat recovery devices of a cryogenic system; numerical simulation of the thermo-hydraulic behaviour of a supercritical CO{sub 2} flow inside a vertical tube; mixed convection inside dual-tube exchangers; development of a nodal approach with homogenization for the simulation of the brazing cycle of a heat exchanger; chaotic exchanger for the cooling of low temperature fuel cells; structural optimization of the internal fins of a cylindrical generator; a new experimental approach for the study of the local boiling inside the channels of exchangers with plates and fins; experimental study of the flow regimes of boiling hydrocarbons on a bundle of staggered tubes; energy study of heat recovery exchangers used in Claude-type refrigerating systems; general model of Carnot engine submitted to various operating constraints; the free pistons Stirling cogeneration system; natural gas supplied cogeneration system with polymer membrane fuel cell; influence of the CRN coating on the heat flux inside the tool during the wood unrolling process; transport and mixture of a passive scalar injected inside the wake of a Ahmed body; control of a laser welding-brazing process by infrared thermography; 2D self-adaptative method for contours detection: application to the images of an aniso-thermal jet; exergy and exergy-economical study of an 'Ericsson' engine-based micro-cogeneration system; simplified air-conditioning of telephone switching equipments; parametric study of the 'low-energy' individual dwelling; brief synthesis of

  17. First principles investigation of interaction between impurity atom (Si, Ge, Sn) and carbon atom in diamond-like carbon system

    International Nuclear Information System (INIS)

    Li, Xiaowei; Wang, Aiying; Lee, Kwang-Ryeol

    2012-01-01

    The interaction between impurity atom (Si, Ge, and Sn) and carbon atom in diamond-like carbon (DLC) system was investigated by the first principles simulation method based on the density functional theory. The tetrahedral configuration was selected as the calculation model for simplicity. When the bond angle varied in a range of 90°–130° from the equivalent state of 109.471°, the distortion energy and the electronic structures including charge density of the highest occupied molecular orbital (HOMO) and partial density of state (PDOS) in the different systems were calculated. The results showed that the addition of Si, Ge and Sn atom into amorphous carbon matrix significantly decreased the distortion energy of the system as the bond angles deviated from the equilibrium one. Further studies of the HOMO and PDOS indicated that the weak covalent bond between Si(Ge, Sn) and C atoms was formed with the decreased strength and directionality, which were influenced by the electronegative difference. These results implied that the electron transfer behavior at the junction of carbon nano-devices could be tailored by the impurity element, and the compressive stress in DLC films could be reduced by the incorporation of Si, Ge and Sn because of the formation of weaker covalent bonds. - Highlights: ►Distortion energy after bond angle distortion was decreased comparing with C-C unit. ►The weak covalent bond was formed between impurity atoms and corner carbon atoms. ►Observed electron transfer behavior affected the strength and directionality of bond. ►Reduction of strength and directionality of bond contributed to small energy change.

  18. New analytic and computational techniques for finite temperature condensed matter systems

    International Nuclear Information System (INIS)

    Arias, T.A.

    1992-01-01

    By employing a special summation technique we find that the breakdown of the Meissner-Ochsenfeld effect in the three dimensional Bose gas as the applied field passes;through its critical value is an entropy driven weakly first order transition, rather than the second order transition usually ascribed to the system. The transition is second order at the usual Bose condensation temperature T c as well as at T = O, with a line o first order transition connecting these critical points. The first order transitions make the Bose gas resemble familiar superconductors, and a Landau-Ginzburg analysis indicates that the Bose gas is always a type I superconductor. We employ the recently introduce conjugate-gradient methods for minimization of the electronic energy functional to perform an extensive ab initio study of the Σ = 5 tilt [310] grain boundary in germanium. We find that the boundary reliably reconstructs to the tetrahedrally bonded network observed in HREM experiments without the proliferation of false local minima observed in similar twist boundaries. The reduced density of bonds crossing the grain boundary plan leads us to conjecture that the boundary may be a preferred fracture interface. We then combine these conjugate-gradient methods with a new technique for generating trail wavefunctions to produce an efficient ab initio molecular dynamics scheme that is that is at least two orders of magnitude more accurate than previous schemes and thus allows accurate calculation of dynamic correlation functions while maintaining tolerable energy conservation for microcanonical averages of those correlation function over picosecond time scales. We present two advances which greatly enhance the efficiency of our new ab initio molecular dynamics technique. We introduce a class of generalizations of traditional Fermionic energy functionals which allow us to lift the orthonormality constraints on the single particle orbitals and thus speed convergence

  19. Data Systems vs. Information Systems

    OpenAIRE

    Amatayakul, Margret K.

    1982-01-01

    This paper examines the current status of “hospital information systems” with respect to the distinction between data systems and information systems. It is proposed that the systems currently existing are incomplete data dystems resulting in ineffective information systems.

  20. EXPERT SYSTEMS

    OpenAIRE

    Georgiana Marin; Mihai Catalin Andrei

    2011-01-01

    In recent decades IT and computer systems have evolved rapidly in economic informatics field. The goal is to create user friendly information systems that respond promptly and accurately to requests. Informatics systems evolved into decision assisted systems, and such systems are converted, based on gained experience, in expert systems for creative problem solving that an organization is facing. Expert systems are aimed at rebuilding human reasoning on the expertise obtained from experts, sto...

  1. On numerical regularity of the face-to-face longest-edge bisection algorithm for tetrahedral partitions

    Czech Academy of Sciences Publication Activity Database

    Hannukainen, A.; Korotov, S.; Křížek, Michal

    2014-01-01

    Roč. 90, Part A (2014), s. 34-41 ISSN 0167-6423 R&D Projects: GA ČR GA14-02067S Institutional support: RVO:67985840 Keywords : bisection algorithm * conforming finite element method * regular family of partitions Subject RIV: BA - General Mathematics Impact factor: 0.715, year: 2014 http://www.sciencedirect.com/science/article/pii/S0167642313001226

  2. Three-dimensional dynamic rupture simulation with a high-order discontinuous Galerkin method on unstructured tetrahedral meshes

    KAUST Repository

    Pelties, Christian; de la Puente, Josep; Ampuero, Jean-Paul; Brietzke, Gilbert B.; Kä ser, Martin

    2012-01-01

    Accurate and efficient numerical methods to simulate dynamic earthquake rupture and wave propagation in complex media and complex fault geometries are needed to address fundamental questions in earthquake dynamics, to integrate seismic and geodetic

  3. Methods of quantum chemistry and nanotechnology as applied to the study of the energy states of amorphous tetrahedral structures

    Directory of Open Access Journals (Sweden)

    B. A. Golodenko

    2013-01-01

    Full Text Available The technique and results of an experimental research of power conditions of amorphous alloy hydrogenated carbide silicon is described. Application of power spectra of a silicon valence zone for definition phase structure of its amorphous hydrogenated carbide is shown. Quantitative dependence of a share carbide phases of silicon in structure of its alloy from the maintenance of methane in an initial gas mix is established.

  4. Ab initio van der waals interactions in simulations of water alter structure from mainly tetrahedral to high-density-like

    DEFF Research Database (Denmark)

    Møgelhøj, Andreas; Kelkkanen, Kari André; Wikfeldt, K Thor

    2011-01-01

    The structure of liquid water at ambient conditions is studied in ab initio molecular dynamics simulations in the NVE ensemble using van der Waals (vdW) density-functional theory, i.e., using the new exchange-correlation functionals optPBE-vdW and vdW-DF2, where the latter has softer nonlocal...... protocol could cause the deviation. An O-O PCF consisting of a linear combination of 70% from vdW-DF2 and 30% from low-density liquid water, as extrapolated from experiments, reproduces near-quantitatively the experimental O-O PCF for ambient water. This suggests the possibility that the new functionals...... shows some resemblance with experiment for high-density water ( Soper , A. K. and Ricci , M. A. Phys. Rev. Lett. 2000 , 84 , 2881 ), but not directly with experiment for ambient water. Considering the accuracy of the new functionals for interaction energies, we investigate whether the simulation...

  5. Multinuclear NMR spectroscopy of the tetrahedral uranium(IV) complex U(BH3CH3)4

    International Nuclear Information System (INIS)

    Gamp, E.; Shinomoto, R.; Edelstein, N.; McGarvey, B.R.

    1987-01-01

    The temperature dependence of the 1 H, 11 B, and 13 C NMR spectra of T/sub d/ U(BH 3 CH 3 ) 4 in solution is reported. The paramagnetic shifts are interpreted as originating purely from spin delocalization mechanisms with no contribution from the metal-orbital dipolar interaction. It is shown that the temperature dependence of both 1 H shifts (bridging and terminal protons) is identical with that calculated from a polarization theory which assumes the shift is proportional to the average value of electron spin in the inner 5f orbitals. The proportionality constant is -5.64 MHz for the bridging protons and -0.59 MHz for the terminal protons. The temperature dependences of 11 B and 13 shifts are found to depart significantly from that predicted by the polarization theory with the largest deviations shown by the 11 B shifts. It is shown how those deviations can be accounted for by postulating a second spin delocalization through direct covalency involving molecular orbitals formed from the uranium 5f orbitals and ligand s and p orbitals. 29 references, 4 figures, 3 tables

  6. Coordination Behavior of Ni2+, Cu2+, and Zn2+ in Tetrahedral 1-Methylimidazole Complexes: A DFT/CSD Study

    OpenAIRE

    Tetteh, Samuel

    2018-01-01

    The interaction between nickel (Ni2+), copper (Cu2+), and zinc (Zn2+) ions and 1-methylimidazole has been studied by exploring the geometries of eleven crystal structures in the Cambridge Structural Database (CSD). The coordination behavior of the respective ions was further investigated by means of density functional theory (DFT) methods. The gas-phase complexes were fully optimized using B3LYP/GENECP functionals with 6-31G∗ and LANL2DZ basis sets. The Ni2+ and Cu2+ complexes show distorted ...

  7. Multibody Systems

    DEFF Research Database (Denmark)

    Wagner, Falko Jens

    1999-01-01

    Multibody Systems is one area, in which methods for solving DAEs are of special interst. This chapter is about multibody systems, why they result in DAE systems and what kind of problems that can arise when dealing with multibody systems and formulating their corresponding DAE system....

  8. Dynamic rupture scenarios from Sumatra to Iceland - High-resolution earthquake source physics on natural fault systems

    Science.gov (United States)

    Gabriel, Alice-Agnes; Madden, Elizabeth H.; Ulrich, Thomas; Wollherr, Stephanie

    2017-04-01

    Capturing the observed complexity of earthquake sources in dynamic rupture simulations may require: non-linear fault friction, thermal and fluid effects, heterogeneous fault stress and fault strength initial conditions, fault curvature and roughness, on- and off-fault non-elastic failure. All of these factors have been independently shown to alter dynamic rupture behavior and thus possibly influence the degree of realism attainable via simulated ground motions. In this presentation we will show examples of high-resolution earthquake scenarios, e.g. based on the 2004 Sumatra-Andaman Earthquake, the 1994 Northridge earthquake and a potential rupture of the Husavik-Flatey fault system in Northern Iceland. The simulations combine a multitude of representations of source complexity at the necessary spatio-temporal resolution enabled by excellent scalability on modern HPC systems. Such simulations allow an analysis of the dominant factors impacting earthquake source physics and ground motions given distinct tectonic settings or distinct focuses of seismic hazard assessment. Across all simulations, we find that fault geometry concurrently with the regional background stress state provide a first order influence on source dynamics and the emanated seismic wave field. The dynamic rupture models are performed with SeisSol, a software package based on an ADER-Discontinuous Galerkin scheme for solving the spontaneous dynamic earthquake rupture problem with high-order accuracy in space and time. Use of unstructured tetrahedral meshes allows for a realistic representation of the non-planar fault geometry, subsurface structure and bathymetry. The results presented highlight the fact that modern numerical methods are essential to further our understanding of earthquake source physics and complement both physic-based ground motion research and empirical approaches in seismic hazard analysis.

  9. System dynamics

    International Nuclear Information System (INIS)

    Kim, Do Hun; Mun, Tae Hun; Kim, Dong Hwan

    1999-02-01

    This book introduces systems thinking and conceptual tool and modeling tool of dynamics system such as tragedy of single thinking, accessible way of system dynamics, feedback structure and causal loop diagram analysis, basic of system dynamics modeling, causal loop diagram and system dynamics modeling, information delay modeling, discovery and application for policy, modeling of crisis of agricultural and stock breeding products, dynamic model and lesson in ecosystem, development and decadence of cites and innovation of education forward system thinking.

  10. EM study of crystallography and phase relationships in the Be/sub 3/N/sub 2/--BeSiN/sub 2/ system

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, T.M.

    1977-12-01

    Transmission electron microscopy and diffraction have been used to examine structural aspects of phases along the BeSiN/sub 2/-Be/sub 3/N/sub 2/ tie line of the Be-Si-O-N system. Electron diffraction experiments are found to substantiate previous x-ray evidence for the derived structures of BeSiN/sub 2/, ..beta.. Be/sub 3/N/sub 2/, ..cap alpha.. Be/sub 3/N/sub 2/ and the presence of a number of long period superstructures at intermediate compositions. Real space observations using direct fringe and structure imaging techniques have been made and are in agreement with the 15R polytype structure derived from x-ray diffraction data. In addition, these observations indicate that beryllium atoms are preferentially sited in cubic stacked layers, allowing the polytype structures to be described as a coherent intergrowth of layers of the BeSiN/sub 2/ and ..beta.. Be/sub 3/N/sub 2/ structure. Further observations made on a non stoichiometric BeSiN/sub 2/ sample suggests that alternatively the polytypes may be described in terms of a regularly faulted BeSiN/sub 2/ structure. Each fault changes the coordination of tetrahedral sites from base sharing to edge sharing in the fault, allowing excess beryllium atoms to be accommodated in the close packed nitrogen lattice. For larger deviations from the BeSiN/sub 2/ stoichiometric composition a higher density of faults occur which interact to form ordered arrangements and the observed polytype structures. The present observations establish that polytypism in the Be-Si-N system is related to the general phenomenon of crystallographic shear as observed in other complex oxide and ceramic systems. It is suggested that similar faulting may account for the polytype structures in other Sialon systems.

  11. Coupling component systems towards systems of systems

    OpenAIRE

    Autran , Frédéric; Auzelle , Jean-Philippe; Cattan , Denise; Garnier , Jean-Luc; Luzeaux , Dominique; Mayer , Frédérique; Peyrichon , Marc; Ruault , Jean-René

    2008-01-01

    International audience; Systems of systems (SoS) are a hot topic in our "fully connected global world". Our aim is not to provide another definition of what SoS are, but rather to focus on the adequacy of reusing standard system architecting techniques within this approach in order to improve performance, fault detection and safety issues in large-scale coupled systems that definitely qualify as SoS, whatever the definition is. A key issue will be to secure the availability of the services pr...

  12. State-of-the-art 3-D neutronics analysis methods for fusion energy systems

    International Nuclear Information System (INIS)

    Wilson, P.P.H.; Feder, R.; Fischer, U.; Loughlin, M.; Petrizzi, L.; Wu, Y.

    2007-01-01

    Recent advances in radiation transport simulation tools enable an increased fidelity and accuracy in modeling complex geometries in fusion systems. Future neutronics calculations for design and analysis will increasingly be based directly on 3-D CAD-based geometries, allowing enhanced model complexity, reduced human effort and improved quality assurance. Improvements have been made in both stochastic and deterministic radiation transport methodologies. To adapt the MCNP stochastic transport software, the translator approach allows CAD geometries to be converted from their native formats into standard input files, while the direct geometry approach uses computer graphics algorithms to perform the radiation transport on the CAD geometry itself. The former takes advantage of the efficiency of the native MCNP software without modifications while the latter permits the modeling of more complex surfaces. The ATTILA radiation transport package uses a finite-element formulation of the discrete-ordinate methodology to provide a deterministic solution on a tetrahedral mesh derived automatically from a CAD-based geometry. All of these tools are being applied to a dedicated benchmark problem consisting of a 40 degree sector of the ITER machine defined only in a CAD-based solid model. The specific benchmark problems exercise the ability to use a CAD-based geometry to solve a range of fusion neutronics problems including neutron wall loading, deep penetration and narrow duct streaming. The results of this exercise will be used to validate/qualify these tools for use on ITER. At the same time, many of these tools are being used to support the design of ITER components and other related fusion systems. UW has provided high-fidelity nuclear analysis of ITER first wall and shield modules identifying local effects of geometric features. ASIPP has used the MCAM tool to update and extend the existing ITER basic model and used it for neutronics analysis of the proposed Chinese ITER

  13. State-of-the-art 3-D neutronics analysis methods for fusion energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, P.P.H. [Wisconsin-Madison Univ., Madison, WI (United States); Feder, R. [Princeton Plasma Physics Lab. (United States); Fischer, U. [Forschungszentrum Karlsruhe (Germany); Loughlin, M. [United Kingdom Atomic Energy Authority (United Kingdom); Petrizzi, L. [ENEA-Frascati (Italy); Wu, Y. [Academy of Sciences (China). Inst. of Plasma Physics; Youssef, M. [California Univ., Los Angeles, CA (United States)

    2007-07-01

    Recent advances in radiation transport simulation tools enable an increased fidelity and accuracy in modeling complex geometries in fusion systems. Future neutronics calculations for design and analysis will increasingly be based directly on 3-D CAD-based geometries, allowing enhanced model complexity, reduced human effort and improved quality assurance. Improvements have been made in both stochastic and deterministic radiation transport methodologies. To adapt the MCNP stochastic transport software, the translator approach allows CAD geometries to be converted from their native formats into standard input files, while the direct geometry approach uses computer graphics algorithms to perform the radiation transport on the CAD geometry itself. The former takes advantage of the efficiency of the native MCNP software without modifications while the latter permits the modeling of more complex surfaces. The ATTILA radiation transport package uses a finite-element formulation of the discrete-ordinate methodology to provide a deterministic solution on a tetrahedral mesh derived automatically from a CAD-based geometry. All of these tools are being applied to a dedicated benchmark problem consisting of a 40 degree sector of the ITER machine defined only in a CAD-based solid model. The specific benchmark problems exercise the ability to use a CAD-based geometry to solve a range of fusion neutronics problems including neutron wall loading, deep penetration and narrow duct streaming. The results of this exercise will be used to validate/qualify these tools for use on ITER. At the same time, many of these tools are being used to support the design of ITER components and other related fusion systems. UW has provided high-fidelity nuclear analysis of ITER first wall and shield modules identifying local effects of geometric features. ASIPP has used the MCAM tool to update and extend the existing ITER basic model and used it for neutronics analysis of the proposed Chinese ITER

  14. Systems effectiveness

    CERN Document Server

    Habayeb, A R

    1987-01-01

    Highlights three principal applications of system effectiveness: hardware system evaluation, organizational development and evaluation, and conflict analysis. The text emphasizes the commonality of the system effectiveness discipline. The first part of the work presents a framework for system effectiveness, partitioning and hierarchy of hardware systems. The second part covers the structure, hierarchy, states, functions and activities of organizations. Contains an extended Appendix on mathematical concepts and also several project suggestions.

  15. Auxiliary systems

    International Nuclear Information System (INIS)

    Meyer, P.J.

    1981-01-01

    Systems included under the heading ''Reactor Auxillary Systems'' are those immediately involved with the reactor operation. These include the systems for dosing and letdown of reactor coolant, as well as for the chemical dosing, purification and treatment of the reactor coolant and the cooling system in the controlled area. The ancillary systems are mainly responsible for liquid and gaseous treatment and the waste treatment for final storage. (orig.)

  16. Phase relationships in the BaO-Ga2O3-Ta2O5 system and the structure of Ba6Ga21TaO40.

    Science.gov (United States)

    Cao, Jiang; Yu, Xiaodi; Kuang, Xiaojun; Su, Qiang

    2012-07-16

    Phase relationships in the BaO-Ga(2)O(3)-Ta(2)O(5) ternary system at 1200 °C were determined. The A(6)B(10)O(30) tetragonal tungsten bronze (TTB) related solution in the BaO-Ta(2)O(5) subsystem dissolved up to ~11 mol % Ga(2)O(3), forming a ternary trapezoid-shaped TTB-related solid solution region defined by the BaTa(2)O(6), Ba(1.1)Ta(5)O(13.6), Ba(1.58)Ga(0.92)Ta(4.08)O(13.16), and Ba(6)GaTa(9)O(30) compositions in the BaO-Ga(2)O(3)-Ta(2)O(5) system. Two ternary phases Ba(6)Ga(21)TaO(40) and eight-layer twinned hexagonal perovskite solid solution Ba(8)Ga(4-x)Ta(4+0.6x)O(24) were confirmed in the BaO-Ga(2)O(3)-Ta(2)O(5) system. Ba(6)Ga(21)TaO(40) crystallized in a monoclinic cell of a = 15.9130(2) Å, b = 11.7309(1) Å, c = 5.13593(6) Å, β = 107.7893(9)°, and Z = 1 in space group C2/m. The structure of Ba(6)Ga(21)TaO(40) was solved by the charge flipping method, and it represents a three-dimensional (3D) mixed GaO(4) tetrahedral and GaO(6)/TaO(6) octahedral framework, forming mixed 1D 5/6-fold tunnels that accommodate the Ba cations along the c axis. The electrical property of Ba(6)Ga(21)TaO(40) was characterized by using ac impedance spectroscopy.

  17. Bitcoin System

    Directory of Open Access Journals (Sweden)

    Jan Lánský

    2017-06-01

    Full Text Available Cryptocurrency systems are purely digital and decentralized systems that use cryptographic principles to confirm transactions. Bitcoin is the first and also the most widespread cryptocurrency. The aim of this article is to introduce Bitcoin system using a language understandable also to readers without computer science education. This article captures the Bitcoin system from three perspectives: internal structure, network and users. Emphasis is placed on brief and clear definitions (system components and their mutual relationships. A new system view of the stated terms constitutes author’s own contribution.

  18. Theoretical and Experimental Investigations into Novel Oxynitride Discovery in the GaN-TiO2 System at High Pressure

    Directory of Open Access Journals (Sweden)

    Alwin James

    2018-01-01

    Full Text Available We employed ab initio evolutionary algorithm USPEX to speed up the discovery of a novel oxynitride in the binary system of GaN-TiO2 using high-pressure synthesis. A 1:2 mixture of GaN and nanocrystalline TiO2 (anatase was reacted under 1 GPa of pressure and at 1200 °C in a piston cylinder apparatus to produce a mixture of TiO2 (rutile and an unknown phase. From the initial analysis of high resolution neutron and X-ray diffraction data, it is isomorphic with monoclinic V2GaO5 with a unit cell composition of Ga10Ti8O28N2 with the following parameters: monoclinic, space group C2/m, a = 17.823(1 Å, b = 2.9970(1 Å, c = 9.4205(5 Å, β = 98.446(3°; Volume = 497.74(3 Å3. Further, a joint rietveld refinement revealed two distinct regimes—A Ti-rich block and a Ga-rich block. The Ti-rich block consists of four edge-shared octahedra and contains a site which is about 60% occupied by N; this site is bonded to four Ti. The remainder of the block consists of edge linked Ti-octahedral chains linked to the TiN/TiO fragments at octahedral corners partially occupied by nitrogen. The Ga-block contains two symmetry independent octahedral sites, occupied mostly by Ga, and a pure Ga-centered tetrahedral site bonded mostly to oxygen.

  19. JOSHUA system

    International Nuclear Information System (INIS)

    Honeck, H.C.

    1975-04-01

    A major computational system called JOSHUA has been under development at the Savannah River Laboratory since 1968. The JOSHUA System has two major parts: the Operating System and the Application System. The Operating System has been in production use since 1970 and provides data management, terminal, and job execution facilities. The Application System uses these facilities in solving problems in reactor physics and engineering. Features of the Application System are the two-dimensional lattice physics and three-dimensional transient reactor physics capabilities, which have been in use since 1971 and 1974, respectively. The capabilities of the JOSHUA System are summarized, and statistics on size, use, and development effort are provided. (U.S.)

  20. Systems thinking.

    Science.gov (United States)

    Cabrera, Derek; Colosi, Laura; Lobdell, Claire

    2008-08-01

    Evaluation is one of many fields where "systems thinking" is popular and is said to hold great promise. However, there is disagreement about what constitutes systems thinking. Its meaning is ambiguous, and systems scholars have made diverse and divergent attempts to describe it. Alternative origins include: von Bertalanffy, Aristotle, Lao Tsu or multiple aperiodic "waves." Some scholars describe it as synonymous with systems sciences (i.e., nonlinear dynamics, complexity, chaos). Others view it as taxonomy-a laundry list of systems approaches. Within so much noise, it is often difficult for evaluators to find the systems thinking signal. Recent work in systems thinking describes it as an emergent property of four simple conceptual patterns (rules). For an evaluator to become a "systems thinker", he or she need not spend years learning many methods or nonlinear sciences. Instead, with some practice, one can learn to apply these four simple rules to existing evaluation knowledge with transformative results.

  1. Cognitive Systems

    DEFF Research Database (Denmark)

    The tutorial will discuss the definition of cognitive systems as the possibilities to extend the current systems engineering paradigm in order to perceive, learn, reason and interact robustly in open-ended changing environments. I will also address cognitive systems in a historical perspective...... to be modeled within a limited set of predefined specifications. There will inevitably be a need for robust decisions and behaviors in novel situations that include handling of conflicts and ambiguities based on the capability and knowledge of the artificial cognitive system. Further, there is a need...... in cognitive systems include e.g. personalized information systems, sensor network systems, social dynamics system and Web2.0, and cognitive components analysis. I will use example from our own research and link to other research activities....

  2. Crystal Systems.

    Science.gov (United States)

    Schomaker, Verner; Lingafelter, E. C.

    1985-01-01

    Discusses characteristics of crystal systems, comparing (in table format) crystal systems with lattice types, number of restrictions, nature of the restrictions, and other lattices that can accidently show the same metrical symmetry. (JN)

  3. Filter systems

    International Nuclear Information System (INIS)

    Vanin, V.R.

    1990-01-01

    The multidetector systems for high resolution gamma spectroscopy are presented. The observable parameters for identifying nuclides produced simultaneously in the reaction are analysed discussing the efficiency of filter systems. (M.C.K.)

  4. Expert systems

    International Nuclear Information System (INIS)

    Haldy, P.A.

    1988-01-01

    The definitions of the terms 'artificial intelligence' and 'expert systems', the methodology, areas of employment and limits of expert systems are discussed. The operation of an expert system is described, especially the presentation and organization of knowledge as well as interference and control. Methods and tools for expert system development are presented and their application in nuclear energy are briefly addressed. 7 figs., 2 tabs., 6 refs

  5. Expert System

    DEFF Research Database (Denmark)

    Hildebrandt, Thomas Troels; Cattani, Gian Luca

    2016-01-01

    An expert system is a computer system for inferring knowledge from a knowledge base, typically by using a set of inference rules. When the concept of expert systems was introduced at Stanford University in the early 1970s, the knowledge base was an unstructured set of facts. Today the knowledge b...... for the application of expert systems, but also raises issues regarding privacy and legal liability....

  6. Retrofitting Systems

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

    This report gives an overview of the different retrofitting possibilities that are available today. The report looks at both external and internal systems for external wall constructions, roof constructions, floor constructions and foundations. All systems are described in detail in respect to use...... and methods, and the efficiency of the different systems are discussed....

  7. Multifunction system

    International Nuclear Information System (INIS)

    Wauthier, J.; Fiori, R.

    1990-01-01

    The development, the characteristics and the applications of a multifunction system are presented. The system is used on the RBES laboratory pipes, at Marcoule. The system was developed in order to allow, without time loss, the modification of the circuit function by replacing only one component. The following elements form the multifunction system: a fixed base, which is part of the tube, a removable piece, which is inserted into the base, a cover plate and its locking system. The material, chosen among commercial trade marks, required small modifications in order to be used in the circuit [fr

  8. Operating systems

    CERN Document Server

    Tsichritzis, Dionysios C; Rheinboldt, Werner

    1974-01-01

    Operating Systems deals with the fundamental concepts and principles that govern the behavior of operating systems. Many issues regarding the structure of operating systems, including the problems of managing processes, processors, and memory, are examined. Various aspects of operating systems are also discussed, from input-output and files to security, protection, reliability, design methods, performance evaluation, and implementation methods.Comprised of 10 chapters, this volume begins with an overview of what constitutes an operating system, followed by a discussion on the definition and pr

  9. Systems integration.

    Science.gov (United States)

    Siemieniuch, C E; Sinclair, M A

    2006-01-01

    The paper presents a view of systems integration, from an ergonomics/human factors perspective, emphasising the process of systems integration as is carried out by humans. The first section discusses some of the fundamental issues in systems integration, such as the significance of systems boundaries, systems lifecycle and systems entropy, issues arising from complexity, the implications of systems immortality, and so on. The next section outlines various generic processes for executing systems integration, to act as guides for practitioners. These address both the design of the system to be integrated and the preparation of the wider system in which the integration will occur. Then the next section outlines some of the human-specific issues that would need to be addressed in such processes; for example, indeterminacy and incompleteness, the prediction of human reliability, workload issues, extended situation awareness, and knowledge lifecycle management. For all of these, suggestions and further readings are proposed. Finally, the conclusions section reiterates in condensed form the major issues arising from the above.

  10. Ternary systems

    International Nuclear Information System (INIS)

    Kagan, D.N.; Hubberstey, P.; Barker, M.G.

    1985-01-01

    The paper reviews the experimental and theoretical studies carried out on multicomponent alkali metal systems. Solid-liquid phase equilibria studies are mainly concerned with the systems Na-K-Rb and Na-K-Cs, and data on the liquidus temperatures in these systems are presented. The thermodynamic properties of the ternary Na-K-Cs eutectic system have been determined experimentally, and the enthalpy, heat capacity and excess functions of the alloy are given. An analysis of calculational methods used in determining thermodynamic functions of ternary liquid metals systems is described. Finally, data are tabulated for the density, compressibility, saturated vapour pressure, viscosity and thermal conductivity of the ternary Na-K-Cs eutectic system. (UK)

  11. Recommender systems

    CERN Document Server

    Kembellec, Gérald; Saleh, Imad

    2014-01-01

    Acclaimed by various content platforms (books, music, movies) and auction sites online, recommendation systems are key elements of digital strategies. If development was originally intended for the performance of information systems, the issues are now massively moved on logical optimization of the customer relationship, with the main objective to maximize potential sales. On the transdisciplinary approach, engines and recommender systems brings together contributions linking information science and communications, marketing, sociology, mathematics and computing. It deals with the understan

  12. Material Systems

    DEFF Research Database (Denmark)

    Jensen, Mads Brath; Mortensen, Henrik Rubæk; Mullins, Michael

    2009-01-01

    This paper describes and reflects upon the results of an investigative project which explores the setting up of a material system - a parametric and generative assembly consisting of and taking into consideration material properties, manufacturing constraints and geometric behavior. The project...... approaches the subject through the construction of a logic-driven system aiming to explore the possibilities of a material system that fulfills spatial, structural and performative requirements concurrently and how these are negotiated in situations where they might be conflicting....

  13. Systems Engineering

    OpenAIRE

    Vaughan, William W.

    2016-01-01

    The term “systems engineering” when entered into the Google search page, produces a significant number of results, evidence that systems engineering is recognized as being important for the success of essentially all products. Since most readers of this item will be rather well versed in documents concerning systems engineering, I have elected to share some of the points made on this subject in a document developed by the European Cooperation for Space Standardization (ECSS), a component of t...

  14. Energetic Systems

    Data.gov (United States)

    Federal Laboratory Consortium — The Energetic Systems Division provides full-spectrum energetic engineering services (project management, design, analysis, production support, in-service support,...

  15. Intelligent systems

    CERN Document Server

    Irwin, J David

    2011-01-01

    Technology has now progressed to the point that intelligent systems are replacing humans in the decision making processes as well as aiding in the solution of very complex problems. In many cases intelligent systems are already outperforming human activities. Artificial neural networks are not only capable of learning how to classify patterns, such images or sequence of events, but they can also effectively model complex nonlinear systems. Their ability to classify sequences of events is probably more popular in industrial applications where there is an inherent need to model nonlinear system

  16. Systemic darwinism.

    Science.gov (United States)

    Winther, Rasmus Grønfeldt

    2008-08-19

    Darwin's 19th century evolutionary theory of descent with modification through natural selection opened up a multidimensional and integrative conceptual space for biology. We explore three dimensions of this space: explanatory pattern, levels of selection, and degree of difference among units of the same type. Each dimension is defined by a respective pair of poles: law and narrative explanation, organismic and hierarchical selection, and variational and essentialist thinking. As a consequence of conceptual debates in the 20th century biological sciences, the poles of each pair came to be seen as mutually exclusive opposites. A significant amount of 21st century research focuses on systems (e.g., genomic, cellular, organismic, and ecological/global). Systemic Darwinism is emerging in this context. It follows a "compositional paradigm" according to which complex systems and their hierarchical networks of parts are the focus of biological investigation. Through the investigation of systems, Systemic Darwinism promises to reintegrate each dimension of Darwin's original logical space. Moreover, this ideally and potentially unified theory of biological ontology coordinates and integrates a plurality of mathematical biological theories (e.g., self-organization/structure, cladistics/history, and evolutionary genetics/function). Integrative Systemic Darwinism requires communal articulation from a plurality of perspectives. Although it is more general than these, it draws on previous advances in Systems Theory, Systems Biology, and Hierarchy Theory. Systemic Darwinism would greatly further bioengineering research and would provide a significantly deeper and more critical understanding of biological reality.

  17. Caste System

    OpenAIRE

    Hoff, Karla

    2016-01-01

    In standard economics, individuals are rational actors and economic forces undermine institutions that impose large inefficiencies. The persistence of the caste system is evidence of the need for psychologically more realistic models of decision-making in economics. The caste system divides South Asian society into hereditary groups whose lowest ranks are represented as innately polluted. ...

  18. Recommender systems

    OpenAIRE

    Lu L.; Medo M.; Yeung C.H.; Zhang Y.-C.; Zhang Z.-K.; Zhou T.

    2012-01-01

    The ongoing rapid expansion of the Internet greatly increases the necessity of effective recommender systems for filtering the abundant information. Extensive research for recommender systems is conducted by a broad range of communities including social and computer scientists, physicists, and interdisciplinary researchers. Despite substantial theoretical and practical achievements, unification and comparison of different approaches are lacking, which impedes further advances. In this article...

  19. GEOMASS system

    International Nuclear Information System (INIS)

    Ohyama, Takuya; Saegusa, Hiromitsu

    2009-03-01

    As a part of the research and development regarding characterisation of deep geological environment, the GEOMASS (GEOLOGICAL MODELLING ANALYSIS AND SIMULATION SOFTWARE) system has been developed by the Japan Atomic Energy Agency in order to carry out geological and hydrogeological modelling and groundwater flow simulation and so on. The GEOMASS system integrates a commercial geological interpretation system (EarthVision), which is used for geological modelling and visualisation, with a proprietary code for groundwater flow (FracAffinity). This integrated system allows users to make rapid improvement of models as data increases. Also, it is possible to perform more realistic groundwater flow simulation due to the capability of modelling the rock mass as a continuum with discrete hydro-structural features in the rock mass. This paper consists of 'Overview of GEOMASS system', FracAffinity Theoretical Background' and 'FracAffinity User Guide' and is edited as a GEOMASS system manual. 'Overview of GEOMASS system' describes the outline of this system. 'FracAffinity Theoretical Background' describes the information of technical background of FracAffinity software. FracAffinity User Guide' describes the structure of the FracAffinity input files, the usage of FracAffinity Interface and flow-solver. Updating of the FracAffinity has been continued as needed and FracAffinity version3.3 is the latest version at present (July 2008). (author)

  20. Systems integration (automation system). System integration (automation system)

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, K; Komori, T; Fukuma, Y; Oikawa, M [Nippon Steal Corp., Tokyo (Japan)

    1991-09-26

    This paper introduces business activities on an automation systems integration (SI) started by a company in July,1988, and describes the SI concepts. The business activities include, with the CIM (unified production carried out on computers) and AMENITY (living environment) as the mainstays, a single responsibility construction ranging from consultation on structuring optimal systems for processing and assembling industries and intelligent buildings to system design, installation and after-sales services. With an SI standing on users {prime} position taken most importantly, the business starts from a planning and consultation under close coordination. On the conceptual basis of structuring optimal systems using the ompany {prime}s affluent know-hows and tools and adapting and applying with multi-vendors, open networks, centralized and distributed systems, the business is promoted with the accumulated technologies capable of realizing artificial intelligence and neural networks in its background, and supported with highly valuable business results in the past. 10 figs., 1 tab.

  1. Creative Systems

    DEFF Research Database (Denmark)

    Manelius, Anne-Mette; Beim, Anne

    2007-01-01

    Opsamling af diskussioner på konferencen og udstillingen Creative Systems i september/oktober 2007. Konferencen og Udstillingen Creative Systems sætter fokus på systemer som en positiv drivkraft i den kreative skabelsesproces. CINARK inviterede fire internationale kapaciteter, som indenfor hver...... deres felt har beskæftiget sig med udviklingen af systemer. Kieran Timberlake, markant amerikansk tegnestue; Mark West, Professor på University of Manitoba, Canada, og pioner indenfor anvendelse af tekstilforskalling til betonstøbninger; Matilda McQuaid, Arkitekturhistoriker og kurator på udstillingen...... om Extreme Textiles på amerikanske Cooper Hewit Design Museum, samt Professor Ludger Hovestadt, ved ETH, Zürich der fokuserer på udvikling og anvendelse af logaritmiske systemtilgange. Udstillingen diskuterede ud fra deres meget forskellige arbejder, det kreative potentiale i anvendelsen af systemer...

  2. Reactive Systems

    DEFF Research Database (Denmark)

    Aceto, Luca; Ingolfsdottir, Anna; Larsen, Kim Guldstrand

    A reactive system comprises networks of computing components, achieving their goals through interaction among themselves and their environment. Thus even relatively small systems may exhibit unexpectedly complex behaviours. As moreover reactive systems are often used in safety critical systems......, the need for mathematically based formal methodology is increasingly important. There are many books that look at particular methodologies for such systems. This book offers a more balanced introduction for graduate students and describes the various approaches, their strengths and weaknesses, and when...... they are best used. Milner's CCS and its operational semantics are introduced, together with the notions of behavioural equivalences based on bisimulation techniques and with recursive extensions of Hennessy-Milner logic. In the second part of the book, the presented theories are extended to take timing issues...

  3. Upgraded RECOVER system - CASDAC system

    International Nuclear Information System (INIS)

    Yamamoto, Yoichi; Koyama, Kinji

    1992-03-01

    The CASDAC (Containment And Surveillance Data Authenticated Communication) system has been developed by JAERI for nuclear safeguards and physical protection of nuclear material. This system was designed and constructed as an upgraded RECOVER system, design concept of which was based on the original RECOVER system and also the TRANSEAVER system. Both of them were developed several years ago as a remote monitoring system for continual verification of security and safeguards status of nuclear material. The system consists of two subsystems, one of them is a Grand Command Center (GCC) subsystem and the other is a facility subsystem. Communication between the two subsystems is controlled through the international telephone line network. Therefore all communication data are encrypted to prevent access by an unauthorized person who may intend to make a falsification, or tapping. The facility subsystem has an appropriate measure that ensure data security and reliable operation under unattended mode of operator. The software of this system is designed so as to be easily used in other different types of computers. This report describes the outline of the CASDAC system and the results of its performance test. This work has been carried out in the framework of Japan Support Programme for Agency Safeguards (JASPAS) as a project, JA-1. (author)

  4. A Structural Molar Volume Model for Oxide Melts Part I: Li2O-Na2O-K2O-MgO-CaO-MnO-PbO-Al2O3-SiO2 Melts—Binary Systems

    Science.gov (United States)

    Thibodeau, Eric; Gheribi, Aimen E.; Jung, In-Ho

    2016-04-01

    A structural molar volume model was developed to accurately reproduce the molar volume of molten oxides. As the non-linearity of molar volume is related to the change in structure of molten oxides, the silicate tetrahedral Q-species, calculated from the modified quasichemical model with an optimized thermodynamic database, were used as basic structural units in the present model. Experimental molar volume data for unary and binary melts in the Li2O-Na2O-K2O-MgO-CaO-MnO-PbO-Al2O3-SiO2 system were critically evaluated. The molar volumes of unary oxide components and binary Q-species, which are model parameters of the present structural model, were determined to accurately reproduce the experimental data across the entire binary composition in a wide range of temperatures. The non-linear behavior of molar volume and thermal expansivity of binary melt depending on SiO2 content are well reproduced by the present model.

  5. Solubility limits in Mn–Mg ferrites system under hydrothermal conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hemeda, O.M., E-mail: omhemeda@yahoo.co.uk [Physics Department, Faculty of Science, Tanta University, Tanta (Egypt); Mostafa, N.Y. [Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522 (Egypt); Faculty of Science, Taif University, PO Box 888, Al-Haweiah, Taif (Saudi Arabia); Abd Elkader, O.H. [Electron Microscope and Thin Films Department, National Research Center, Dokki 12622, Cairo (Egypt); Electron Microscope Unit, Zoology Department, King Saud University, Riyadh 11451 (Saudi Arabia); Ahmed, M.A. [Physics Department, Faculty of Science, Al Azhar University, Nasr City, Cairo (Egypt)

    2014-09-01

    In the present investigation, we successfully synthesized a pure MnFe{sub 2}O{sub 4} ferrite by the hydrothermal method. Moreover, the effect of Mg ion content on the formation of Mn{sub 1−x}Mg{sub x}Fe{sub 2}O{sub 4} particles (with x varying from 0.1 to 1.0) was also investigated using XRD, SEM, TEM and Mossbauer Spectroscopy. Phases formed in the system Mn{sub 1−x}Mg{sub x}Fe{sub 2}O{sub 4}; 0.0≤x≤1.0 were investigated under hydrothermal conditions at 453 K.The produced phases were characterized by X-ray diffraction, Scanning, transmission microscopy and Mossbauer spectroscopy. The information of composition, cation distribution in the spinel structure and the particle size of the products were obtained. The spinel ferrites; Mn{sub 1−x}Mg{sub x}Fe{sub 2}O{sub 4} were formed in the range 0.0≤x≤0.3. However, sample with x>0.3 showed semi-crystalline magnesium hydroxide (Mg(OH){sub 2}) and hematite (Fe{sub 2}O{sub 3}) beside the ferrite phase. For x=1.0, only magnesium hydroxide and hematite are formed without any ferrites. Particles of uniform size around 10–20 nm were obtained in the spinel structure of Mn{sub 1−x}Mg{sub x}Fe{sub 2}O{sub 4} with x=0.0 and 0.1. The corresponding average crystallite size for each sample was 40.3 nm and 39.2 nm respectively. In addition, the Mossbauer spectra were analyzed into two subspectra, one for the tetrahedral A-site and the other for the octahedral B-site. The Mossbauer parameters were determined and discussed for the studied system. The cation distribution was estimated from the analysis of the Mossbauer spectra as well as the X-ray diffraction patterns. The results showed that Mg ions occupy mainly B-site while both Mn and Fe ions are distributed between A- and B-sites. - Highlights: • Mossbauer characterization of Mg–Mn ferrite prepared by hydrothermal route. • X-ray powder diffraction analysis of Mg–Mn ferrite prepared by hydrothermal route. • Solubility limit of MgMn ferrite under

  6. Watchdog System

    DEFF Research Database (Denmark)

    Madsen, Tanja Kidholm Osmann; Bahnsen, Chris Holmberg; Jensen, Morten Bornø

    This deliverable is part of WP4. Overall WP4 is motivated by the need for automatic systems that can ease the task of annotating massive amounts of traffic data. Concretely this deliverable is related to WP4.2 - the watchdog system. The idea with the watchdog is to develop a system that can remov...... huge chunks of video data where no events/interactions of interest are occurring and hence let a user focus on manually annotation of only the interesting stuff....

  7. Dynamical systems

    CERN Document Server

    Sternberg, Shlomo

    2010-01-01

    Celebrated mathematician Shlomo Sternberg, a pioneer in the field of dynamical systems, created this modern one-semester introduction to the subject for his classes at Harvard University. Its wide-ranging treatment covers one-dimensional dynamics, differential equations, random walks, iterated function systems, symbolic dynamics, and Markov chains. Supplementary materials offer a variety of online components, including PowerPoint lecture slides for professors and MATLAB exercises.""Even though there are many dynamical systems books on the market, this book is bound to become a classic. The the

  8. Water systems

    International Nuclear Information System (INIS)

    Riess, R.

    1980-01-01

    The present paper describes the coolant chemistry and its consequences for 1300 MWsub(e) KWU PWR plants. Some selected systems, i.e. primary heat transport system, steam water cycle and cooling water arrangements, are chosen for this description. Various aspects of coolant chemistry regarding general corrosion, selective types of corrosion and deposits on heat transfer surfaces have been discussed. The water supply systems necessary to fulfill the requirements of the coolant chemistry are discussed as well. It has been concluded that a good operating performance can only be achieved when - beside other factors - the water chemistry has been given sufficient consideration. (orig./RW)

  9. Water systems

    International Nuclear Information System (INIS)

    Riess, R.

    1981-01-01

    The present paper describes the coolant chemistry and its consequences for 1300 MWsub(e) KWU PWR plants. Some selected systems, i.e. primary heat transport system, steam water cycle and cooling water arrangements, are chosen for this description. Various aspects of coolant chemistry regarding general corrosion, selective types of corrosion and deposits on heat transfer surface have been discussed. The water supply systems necessary to fulfill the requirements of the coolant chemistry are discussed as well. It has been concluded that a good operating performance can only be achieved when - beside other factors - the water chemistry has been given sufficient consideration. (orig./RW)

  10. Imaging system

    International Nuclear Information System (INIS)

    Froggatt, R.J.

    1981-01-01

    The invention provides a two dimensional imaging system in which a pattern of radiation falling on the system is detected to give electrical signals for each of a plurality of strips across the pattern. The detection is repeated for different orientations of the strips and the whole processed by compensated back projection. For a shadow x-ray system a plurality of strip x-ray detectors are rotated on a turntable. For lower frequencies the pattern may be rotated with a Dove prism and the strips condensed to suit smaller detectors with a cylindrical lens. (author)

  11. Kaonic systems

    Directory of Open Access Journals (Sweden)

    Oset E.

    2012-12-01

    Full Text Available I make a short review of the situation of the kaonic systems, with novel information supporting the two Λ(1405 states from the K-d → nπΣ reaction. A review is made of the K¯$ar K$NN system with recent calculations converging to smaller bindings and larger widths. Novel systems involving two kaons and one nucleon or three kaons are also reported and finally a short discussion is made of the analogous state DNN for which recent studies find a large binding and a small width.

  12. The systems integration modeling system

    International Nuclear Information System (INIS)

    Danker, W.J.; Williams, J.R.

    1990-01-01

    This paper discusses the systems integration modeling system (SIMS), an analysis tool for the detailed evaluation of the structure and related performance of the Federal Waste Management System (FWMS) and its interface with waste generators. It's use for evaluations in support of system-level decisions as to FWMS configurations, the allocation, sizing, balancing and integration of functions among elements, and the establishment of system-preferred waste selection and sequencing methods and other operating strategies is presented. SIMS includes major analysis submodels which quantify the detailed characteristics of individual waste items, loaded casks and waste packages, simulate the detailed logistics of handling and processing discrete waste items and packages, and perform detailed cost evaluations

  13. ring system

    African Journals Online (AJOL)

    1,3,2-DIAZABORACYCLOALKANE. RING SYSTEM. Negussie Retta" and Robert H. Neilson. 'Department of Chemistry, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia. Department of Chemistry, Texas Christian University.

  14. Septic Systems

    Science.gov (United States)

    The web site provides guidance and technical assistance for homeowners, government officials, industry professionals, and EPA partners about how to properly develop and manage individual onsite and community cluster systems that treat domestic wastewater.

  15. Respiratory system

    Science.gov (United States)

    Bartlett, R. G., Jr.

    1973-01-01

    The general anatomy and function of the human respiratory system is summarized. Breathing movements, control of breathing, lung volumes and capacities, mechanical relations, and factors relevant to respiratory support and equipment design are discussed.

  16. Bubble systems

    CERN Document Server

    Avdeev, Alexander A

    2016-01-01

    This monograph presents a systematic analysis of bubble system mathematics, using the mechanics of two-phase systems in non-equilibrium as the scope of analysis. The author introduces the thermodynamic foundations of bubble systems, ranging from the fundamental starting points to current research challenges. This book addresses a range of topics, including description methods of multi-phase systems, boundary and initial conditions as well as coupling requirements at the phase boundary. Moreover, it presents a detailed study of the basic problems of bubble dynamics in a liquid mass: growth (dynamically and thermally controlled), collapse, bubble pulsations, bubble rise and breakup. Special emphasis is placed on bubble dynamics in turbulent flows. The analysis results are used to write integral equations governing the rate of vapor generation (condensation) in non-equilibrium flows, thus creating a basis for solving a number of practical problems. This book is the first to present a comprehensive theory of boil...

  17. Systems Biology

    Indian Academy of Sciences (India)

    IAS Admin

    study and understand the function of biological systems, particu- larly, the response of such .... understand the organisation and behaviour of prokaryotic sys- tems. ... relationship of the structure of a target molecule to its ability to bind a certain ...

  18. Bricks / Systems

    DEFF Research Database (Denmark)

    At first glance, this book may appear eclectic. It contains writings from architectural practice in a language and structure based on subjective views and experiences, combined with research contributions based on systematic design investigations of discrete computational systems. Discussions range......, and it aims to illustrate and identify new modes of working in architecture, particularly with regards to brickwork and other complex systems of modular assemblies, whether physical or digital....

  19. Expert Systems

    OpenAIRE

    Lucas, P.J.F.

    2005-01-01

    Expert systems mimic the problem-solving activity of human experts in specialized domains by capturing and representing expert knowledge. Expert systems include a knowledge base, an inference engine that derives conclusions from the knowledge, and a user interface. Knowledge may be stored as if-then rules, orusing other formalisms such as frames and predicate logic. Uncertain knowledge may be represented using certainty factors, Bayesian networks, Dempster-Shafer belief functions, or fuzzy se...

  20. Nanorobotic Systems

    Directory of Open Access Journals (Sweden)

    Lixin Dong

    2008-11-01

    Full Text Available Two strategies towards the realization of nanotechnology have been presented, i.e., top-down and bottom up. The former one is mainly based on nanofabrication and includes technologies such as nano-lithography, nano-imprint, and etching. Presently, they are still 2D fabrication processes with low resolution. The later one is an assembly-based technique. At present, it includes such items as self-assembly, dip-pen lithography, and directed self-assembly. These techniques can generate regular nano patterns in large scales. To fabricate 3D complex nano devices there are still no effective ways by so far. Here we show our effort on the development of a nano laboratory, a prototype nanomanufacturing system, based on nanorobotic manipulations. In which, we take a hybrid strategy as shown in Fig. 1. In this system, nano fabrication and nano assembly can be performed in an arbitrary order to construct nano building blocks and finally nano devices. The most important feature in this system is that the products can be fed back into the system to shrink the system part by part leading to nanorobots. Property characterization can be performed in each intermediate process. Due to the nanorobotic manipulation system, dynamic measurement can be performed rather than conventional static observations.

  1. Fiscal system analysis - contractual systems

    International Nuclear Information System (INIS)

    Kaiser, M.J.

    2006-01-01

    Production sharing contracts are one of the most popular forms of contractual system used in petroleum agreements around the world, but the manner in which the fiscal terms and contract parameters impact system measures is complicated and not well understood. The purpose of this paper is to quantify the influence of private and market uncertainty in contractual fiscal systems. A meta-modelling approach is employed that couples the results of a simulation model with regression analysis to construct numerical functionals that quantify the fiscal regime. Relationships are derived that specify how the present value, rate of return, and take statistics vary as a function of the system parameters. The deepwater Girassol field development in Angola is taken as a case study. (author)

  2. Reactor system

    International Nuclear Information System (INIS)

    Miyano, Hiroshi; Narabayashi, Naoshi.

    1990-01-01

    The represent invention concerns a reactor system with improved water injection means to a pressure vessel of a BWR type reactor. A steam pump is connected to a heat removing system pipeline, a high pressure water injection system pipeline and a low pressure water injection system pipeline for injecting water into the pressure vessel. A pump actuation pipeline is disposed being branched from a main steam pump or a steam relieaf pipeline system, through which steams are supplied to actuate the steam pump and supply cooling water into the pressure vessel thereby cooling the reactor core. The steam pump converts the heat energy into the kinetic energy and elevates the pressure of water to a level higher than the pressure of the steams supplied by way of a pressure-elevating diffuser. Cooling water can be supplied to the pressure vessel by the pressure elevation. This can surely inject cooling water into the pressure vessel upon loss of coolant accident or in a case if reactor scram is necessary, without using an additional power source. (I.N.)

  3. A widely adaptable habitat construction system utilizing space resources

    Science.gov (United States)

    Wykes, Harry B.

    1993-01-01

    This study suggests that the cost of providing accommodations for various manned activities in space may be reduced by the extensive use of resources that are commonly found throughout the solar system. Several concepts are proposed for converting these resources into simple products with many uses. Concrete is already being considered as a possible moonbase material. Manufacturing equipment should be as small and simple as possible, which leads to the idea of molding it into miniature modules that can be produced and assembled in large numbers to create any conceivable shape. Automated equipment could build up complex structures by laying down layer after layer in a process resembling stereolithography. These tiny concrete blocks handle compression loads and provide a barrier to harmful radiation. They are joined by a web of tension members that could be made of wire or fiber-reinforced plastic. The finished structure becomes air-tight with the addition of a flexible liner. Wire can be made from the iron modules found in lunar soil. In addition to its structural role, a relatively simple apparatus can bend and weld it into countless products like chairs and shelving that would otherwise need to be supplied from Earth. Wire woven into a loose blanket could be an effective micrometeoroid shield, tiny wire compression beams could be assembled into larger beams which in turn form larger beams to create very large space-frame structures. A technology developed with lunar materials could be applied to the moons of Mars or the asteroids. To illustrate its usefulness several designs for free-flying habitats are presented. They begin with a minimal self-contained living unit called the Cubicle. It may be multiplied into clusters called Condos. These are shown in a rotating tether configuration that provides a substitute for gravity. The miniature block proposal is compared with an alternate design based on larger triangular components and a tetrahedral geometry. The

  4. ARAC system

    International Nuclear Information System (INIS)

    Kelly, M.F.; Wyman, R.H.

    1975-01-01

    In spite of the remarkable safety record of the nuclear industry as a whole, recent public concern over the potential impact of the industry's accelerated growth has prompted ERDA to expand its emergency response procedures. The Atmospheric Release Advisory Capability, ARAC, is a computer communications system designed to enhance the existing emergency response capability of ERDA nuclear facilities. ARAC will add at least two new functions to this capability: centralized, real-time data acquisition and storage, and simulation of the long range atmospheric transport of hazardous materials. To perform these functions, ARAC employs four major sub-systems or facilities: the site facility, the central facility, the global weather center and the regional model. The system has been under development for the past two years at the Lawrence Livermore Laboratory of the University of California

  5. Microbiology System

    Science.gov (United States)

    1992-01-01

    Technology originating in a NASA-sponsored study of the measurement of microbial growth in zero gravity led to the development of Biomerieux Vitek, Inc.'s VITEK system. VITEK provides a physician with accurate diagnostic information and identifies the most effective medication. Test cards are employed to identify organisms and determine susceptibility to antibiotics. A photo-optical scanner scans the card and monitors changes in the growth of cells contained within the card. There are two configurations - VITEK and VITEK JR as well as VIDAS, a companion system that detects bacteria, viruses, etc. from patient specimens. The company was originally created by McDonnell Douglas, the NASA contractor.

  6. Spin systems

    CERN Document Server

    Caspers, W J

    1989-01-01

    This book is about spin systems as models for magnetic materials, especially antiferromagnetic lattices. Spin-systems are well-defined models, for which, in special cases, exact properties may be derived. These special cases are for the greater part, one- dimensional and restricted in their applicability, but they may give insight into general properties that also exist in higher dimension. This work pays special attention to qualitative differences between spin lattices of different dimensions. It also replaces the traditional picture of an (ordered) antiferromagnetic state of a Heisenberg sy

  7. Distributed systems

    CERN Document Server

    Van Steen, Maarten

    2017-01-01

    For this third edition of "Distributed Systems," the material has been thoroughly revised and extended, integrating principles and paradigms into nine chapters: 1. Introduction 2. Architectures 3. Processes 4. Communication 5. Naming 6. Coordination 7. Replication 8. Fault tolerance 9. Security A separation has been made between basic material and more specific subjects. The latter have been organized into boxed sections, which may be skipped on first reading. To assist in understanding the more algorithmic parts, example programs in Python have been included. The examples in the book leave out many details for readability, but the complete code is available through the book's Website, hosted at www.distributed-systems.net.

  8. Characterization of copper-zinc mixed oxide system in relation to different precursor structure and morphology

    Energy Technology Data Exchange (ETDEWEB)

    Porta, P; De Rossi, S; Ferraris, G [Centro del CNR su ' Struttura e Attivia Catalitica di Sistemi di Ossidi' (SACSO), Rome (Italy); Pompa, F [ENEA, TIB Scienza dei Materiali, Rome (Italy)

    1991-03-01

    Hydroxycarbonate and hydroxynitrate precursors of CuO-ZnO catalysts (Cu/Zn atomic ratio=67/33) have been prepared by two different methods; the precursor obtained by precipitation at 333 K and constant pH=8 from mixed nitrate solution with excess of sodium bicarbonate consisted of zincian malachite and aurichalcite, while that obtained by addition of sodium carbonate solution to Cu-Zn nitrate solution is essentially copper hydroxynitrate plus some amount of aurichalcite. By thermal decomposition at 623 K both types of precursor gave a mixture of CuO and ZnO. The mixed oxides were then treated at 873, 1073 and 1273 K in air. X-ray diffraction, diffuse reflectance spectroscopy, scanning electron microscopy and surface area determination were used to characterize the mixed oxide systems. The precursor containing zincian malachite plus aurichalcite, after calcination at 623 K gave rise to well dispersed and much smaller particles of CuO and ZnO than the precursor containing copper hydroxynitrate plus aurichalcite. No Cu{sup 2+} in solid solution in the ZnO zincite structure Zn{sup 2+} in the CuO tenorite lattice were detected by reflectance spectroscopy up to 873 K; the presence of tetrahedral copper (Cu{sub x}Zn{sub 1-x}O solid solution formation at least at the surface) was evident only in samples calcined at temperatures higher than 1073 K. X-ray diffraction analysis for lattice parameter determination showed that only for samples treated at 1273 K both Cu{sub x}Zn{sub 1-x}O and Zn{sub y}Cu{sub 1-y}O solid solution formations are detectable. An unexpected volume decrease of Zn{sub y}Cu{sub 1-y}O with respect to pure CuO was revealed; the introduction of zinc in the tenorite structure probably changes the local metal symmetry from nearly square planar towards octahedral, producing an overall less distorted and more compact structure. (orig.).

  9. Immune System

    Science.gov (United States)

    ... of the Immune System Print en español El sistema inmunitario Whether you're stomping through the showers ... of Use Notice of Nondiscrimination Visit the Nemours Web site. Note: All information on TeensHealth® is for ...

  10. Operating Systems

    Indian Academy of Sciences (India)

    areas in which this type is useful are multimedia, virtual reality, and advanced scientific projects such as undersea exploration and planetary rovers. Because of the expanded uses for soft real-time functionality, it is finding its way into most current operating systems, including major versions of Unix and Windows NT OS.

  11. Barrier Systems

    NARCIS (Netherlands)

    Heteren, S. van

    2015-01-01

    Barrier-system dynamics are a function of antecedent topography and substrate lithology, Relative sea-level (RSL) changes, sediment availability and type, climate, vegetation type and cover, and various aero- and hydrodynamic processes during fair-weather conditions and extreme events. Global change

  12. Systems Science

    Science.gov (United States)

    Christakis, Alexander; Hammond, Debora; Jackson, Michael; Laszlo, Alexander; Mitroff, Ian; Snowden, Dave; Troncale, Len; Carr-Chellman, Alison; Spector, J. Michael; Wilson, Brent

    2013-01-01

    Scholars representing the field of systems science were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Alexander Christakis, Debora Hammond, Michael Jackson, Alexander Laszlo, Ian Mitroff, Dave…

  13. Transport system

    NARCIS (Netherlands)

    Drenth, K.F.

    1999-01-01

    The transport system comprises at least one road surface (2) and at least one vehicle (4) on wheels (6). The road surface (2) has a substantially bowl-shaped cross section and the vehicle (4) is designed so that the wheels (6) run directly on the road surface (2) while the road surface (2) acts as a

  14. Quorum Systems

    DEFF Research Database (Denmark)

    Wattenhofer, Roger; Förster, Klaus-Tycho

    2016-01-01

    What happens if a single server is no longer powerful enough to service all your customers? The obvious choice is to add more servers and to use the majority approach (e.g. Paxos, Chapter 2) to guarantee consistency. However, even if you buy one million servers, a client still has to access more ...... study the theory behind overlapping sets, known as quorum systems....

  15. System Dynamics

    Science.gov (United States)

    Morecroft, John

    System dynamics is an approach for thinking about and simulating situations and organisations of all kinds and sizes by visualising how the elements fit together, interact and change over time. This chapter, written by John Morecroft, describes modern system dynamics which retains the fundamentals developed in the 1950s by Jay W. Forrester of the MIT Sloan School of Management. It looks at feedback loops and time delays that affect system behaviour in a non-linear way, and illustrates how dynamic behaviour depends upon feedback loop structures. It also recognises improvements as part of the ongoing process of managing a situation in order to achieve goals. Significantly it recognises the importance of context, and practitioner skills. Feedback systems thinking views problems and solutions as being intertwined. The main concepts and tools: feedback structure and behaviour, causal loop diagrams, dynamics, are practically illustrated in a wide variety of contexts from a hot water shower through to a symphony orchestra and the practical application of the approach is described through several real examples of its use for strategic planning and evaluation.

  16. System Description:

    DEFF Research Database (Denmark)

    Schürmann, Carsten; Poswolsky, Adam

    2009-01-01

    Delphin is a functional programming language [Adam Poswolsky and Carsten Schürmann. Practical programming with higher-order encodings and dependent types. In European Symposium on Programming (ESOP), 2008] utilizing dependent higher-order datatypes. Delphin's two-level type-system cleanly separates...

  17. Immune System

    Science.gov (United States)

    A properly functioning immune system is essential to good health. It defends the body against infectious agents and in some cases tumor cells. Individuals with immune deficiencies resulting from genetic defects, diseases (e.g., AIDS, leukemia), or drug therapies are more suscepti...

  18. Bioenergy systems

    International Nuclear Information System (INIS)

    Mitchell, C.P.

    1997-01-01

    The objective of this paper is to demonstrate that a bioenergy system has to be considered as an integrated process in which each stage or step interacts with other steps in the overall process. There are a number of stages in the supply and conversion of woody biomass for energy. Each step in the chain has implications for the next step and for overall system efficiency. The resource can take many forms and will have varying physical and chemical characteristics which will influence the efficiency and cost of conversion. The point in the supply chain at which size and moisture content is reduced and the manner in which it is done is influential in determining feedstock delivered cost and overall system costs. To illustrate the interactions within the overall system, the influence of the nature, size and moisture content of delivered feedstocks on costs of generating electricity via thermal conversion processes is examined using a model developed to investigate the inter-relationships between the stages in the supply chain. (author)

  19. Urogenital system

    International Nuclear Information System (INIS)

    Hamm, B.; Asbach, P.; Beyersdorff, D.; Hein, P.; Zaspel, U.

    2007-01-01

    The book is focussed on the radiological diagnostics of diseases in the urogential system. The description of the specific diseases, the identification by modern imaging techniques, the interpretation of examinatory results and therapeutic options are systematically treated in 4 chapters: kidney and adrenal glands, urinary tract, male genitals, female genitals

  20. Mirror systems.

    Science.gov (United States)

    Fogassi, Leonardo; Ferrari, Pier Francesco

    2011-01-01

    Mirror neurons are a class of visuomotor neurons, discovered in the monkey premotor cortex and in an anatomically connected area of the inferior parietal lobule, that activate both during action execution and action observation. They constitute a circuit dedicated to match actions made by others with the internal motor representations of the observer. It has been proposed that this matching system enables individuals to understand others' behavior and motor intentions. Here we will describe the main features of mirror neurons in monkeys. Then we will present evidence of the presence of a mirror system in humans and of its involvement in several social-cognitive functions, such as imitation, intention, and emotion understanding. This system may have several implications at a cognitive level and could be linked to specific social deficits in humans such as autism. Recent investigations addressed the issue of the plasticity of the mirror neuron system in both monkeys and humans, suggesting also their possible use in rehabilitation. WIREs Cogn Sci 2011 2 22-38 DOI: 10.1002/wcs.89 For further resources related to this article, please visit the WIREs website. Copyright © 2010 John Wiley & Sons, Ltd.

  1. Systemic Planning

    DEFF Research Database (Denmark)

    Leleur, Steen

    This book presents principles and methodology for planning in a complex world. It sets out a so-called systemic approach to planning, among other things, by applying “hard” and “soft” methodologies and methods in combination. The book is written for Ph.D and graduate students in engineering...

  2. Energy systems

    International Nuclear Information System (INIS)

    Haefele, W.

    1974-01-01

    Up to the present the production, transmission and distribution of energy has been considered mostly as a fragmented problem; at best only subsystems have been considered. Today the scale of energy utilization is increasing rapidly, and correspondingly, the reliance of societies on energy. Such strong quantitative increases influence the qualitative nature of energy utilization in most of its aspects. Resources, reserves, reliability and environment are among the key words that may characterize the change in the nature of the energy utilization problem. Energy can no longer be considered an isolated technical and economical problem, rather it is embedded in the ecosphere and the society-technology complex. Restraints and boundary conditions have to be taken into account with the same degree of attention as in traditional technical problems, for example a steam turbine. This results in a strong degree of interweaving. Further, the purpose of providing energy becomes more visible, that is, to make survival possible in a civilized and highly populated world on a finite globe. Because of such interweaving and finiteness it is felt that energy should be considered as a system and therefore the term 'energy systems' is used. The production of energy is only one component of such a system; the handling of energy and the embedding of energy into the global and social complex in terms of ecology, economy, risks and resources are of similar importance. he systems approach to the energy problem needs more explanation. This paper is meant to give an outline of the underlying problems and it is hoped that by so doing the wide range of sometimes confusing voices about energy can be better understood. Such confusion starts already with the term 'energy crisis'. Is there an energy crisis or not? Much future work is required to tackle the problems of energy systems. This paper can only marginally help in that respect. But it is hoped that it will help understand the scope of the

  3. Energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Haefele, W [Nuclear Research Centre, Applied Systems Analysis and Reactor Physics, Karlsruhe (Germany); International Institute for Applied Systems Analysis, Laxenburg (Austria)

    1974-07-01

    Up to the present the production, transmission and distribution of energy has been considered mostly as a fragmented problem; at best only subsystems have been considered. Today the scale of energy utilization is increasing rapidly, and correspondingly, the reliance of societies on energy. Such strong quantitative increases influence the qualitative nature of energy utilization in most of its aspects. Resources, reserves, reliability and environment are among the key words that may characterize the change in the nature of the energy utilization problem. Energy can no longer be considered an isolated technical and economical problem, rather it is embedded in the ecosphere and the society-technology complex. Restraints and boundary conditions have to be taken into account with the same degree of attention as in traditional technical problems, for example a steam turbine. This results in a strong degree of interweaving. Further, the purpose of providing energy becomes more visible, that is, to make survival possible in a civilized and highly populated world on a finite globe. Because of such interweaving and finiteness it is felt that energy should be considered as a system and therefore the term 'energy systems' is used. The production of energy is only one component of such a system; the handling of energy and the embedding of energy into the global and social complex in terms of ecology, economy, risks and resources are of similar importance. he systems approach to the energy problem needs more explanation. This paper is meant to give an outline of the underlying problems and it is hoped that by so doing the wide range of sometimes confusing voices about energy can be better understood. Such confusion starts already with the term 'energy crisis'. Is there an energy crisis or not? Much future work is required to tackle the problems of energy systems. This paper can only marginally help in that respect. But it is hoped that it will help understand the scope of the

  4. TUBO system

    International Nuclear Information System (INIS)

    Barbosa, H.J.C.; Guerreiro, J.N.C.; Toledo, E.M.

    1980-01-01

    Proceedings recently incorporated to TUBO system like the seismic analysis and the stress verification acccording to ASME-Boiler Rule and Pressure Vessel Code-section III are presented. The seismic analysis comprehend the consideration of uniform motion of the support, its multiple excitation, and the attainment of the spectral response for both cases. The module for stress verification uses stresses resulting fromthe combination of the loads specified by the user, in the automatic verification of permissible stresses for the pipings class 1 and 2, based on criteria NB-3650 and NC-3650 of ASME. The implementation of these proceedings in the TUBO system are discussed and a numerical example that covers the different phases of a stress analysis in a piping is presented [pt

  5. Solar Systems

    Science.gov (United States)

    1979-01-01

    The solar collectors shown are elements of domestic solar hot water systems produced by Solar One Ltd., Virginia Beach, Virginia. Design of these systems benefited from technical expertise provided Solar One by NASA's Langley Research Center. The company obtained a NASA technical support package describing the d e sign and operation of solar heating equipment in NASA's Tech House, a demonstration project in which aerospace and commercial building technology are combined in an energy- efficient home. Solar One received further assistance through personal contact with Langley solar experts. The company reports that the technical information provided by NASA influenced Solar One's panel design, its selection of a long-life panel coating which increases solar collection efficiency, and the method adopted for protecting solar collectors from freezing conditions.

  6. Bilateral system. The ABACC system

    International Nuclear Information System (INIS)

    Nicolas, Ruben O.

    2001-01-01

    After relating the antecedents of the creation of the Brazilian-Argentine Agency for the Accounting and Control of Nuclear Materials (ABACC), the paper describes the common system of accounting and control set up by Argentina and Brazil. The organization of ABACC is also outlined

  7. Physical system requirements: Overall system

    International Nuclear Information System (INIS)

    1992-01-01

    The Nuclear Waste Policy Act (NWPA) of 1982 assigned to the Department of Energy (DOE) the responsibility for managing the disposal of spent nuclear fuel and high-level radioactive waste and established the Office of Civilian Radioactive Waste Management (OCRWM) for that purpose. The Secretary of Energy, in his November 1989 report to Congress (DOE/RW-0247), announced three new initiatives for conduct of the Civilian Radioactive Waste Management (CRWM) program. One of these initiatives was to establish improved management structure and procedures. In response, OCRWM performed a management study and the Direct subsequently issued the Management Systems Improvement Strategy (MSIS) on August 10, 1990, calling for a rigorous implementation of systems engineering principles with a special emphasis on functional analysis. This approach establishes a framework for integrating the program management efforts with the technical requirements analysis into a single, unified, and consistent program. The functional analysis approach recognizes that just the facilities and equipment comprising the physical waste management system must perform certain functions, so must certain programmatic and management functions be performed within the program in order to successfully bring the physical system into being

  8. Security system

    Science.gov (United States)

    Baumann, Mark J.; Kuca, Michal; Aragon, Mona L.

    2016-02-02

    A security system includes a structure having a structural surface. The structure is sized to contain an asset therein and configured to provide a forceful breaching delay. The structure has an opening formed therein to permit predetermined access to the asset contained within the structure. The structure includes intrusion detection features within or associated with the structure that are activated in response to at least a partial breach of the structure.

  9. Cardiovascular system

    International Nuclear Information System (INIS)

    Soulen, R.L.; Grosh, J.

    1984-01-01

    Invasive cardiovascular diagnostic procedures involve a finite risk and therefore can be recommended only when the benefit appears to exceed the risk by a substantial margin. The risk/benefit ratio varies not only with the procedure concerned but with the status of the vascular system, concomitant diseases, and the risks of both the suspected illness and its treatment. The risks inherent in the procedures per se are detailed in the sections to follow

  10. Priority Systems

    OpenAIRE

    Gössler , Gregor; Sifakis , Joseph

    2004-01-01

    Projet POP_ART; We present a framework for the incremental construction of deadlock-free systems meeting given safety properties. The framework borrows concepts and basic results from the controller synthesis paradigm by considering a step in the construction process as a controller synthesis problem. We show that priorities are expressive enough to represent restrictions induced by deadlock-free controllers preserving safety properties. We define a correspondence between such restrictions an...

  11. Imaging system

    International Nuclear Information System (INIS)

    Rushbrooke, J.G.; Ansorge, R.E.

    1987-01-01

    A moving object such as a container on a conveyor belt is imaged by an optical system onto a charge coupled device array in which the lines of the array are arranged perpendicular to the direction of motion of the object. The speed of movement of the object is sensed to generate electrical signals which are processed to provide shift signals enabling the shifting of data row to row in the array in synchronism with the movement of the container. The electrical charge associated with a given point on the array is transferred from one line to the other until it appears at the last line of the array, from which it is read out in known manner in conjunction with all other electrical charges associated with the row of charge coupled devices in the last line of the array. Due to the integrating effect achieved, the aperture of the imaging system can be much smaller than otherwise would be required, and/or the level of light illumination can be reduced. The imaging system can be applied to X-ray inspection devices, aerial surveillance or scanning of moving documents in copying processes. (author)

  12. Braking system

    Science.gov (United States)

    Norgren, D.U.

    1982-09-23

    A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling means causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location.

  13. Protecting information in systems of systems

    NARCIS (Netherlands)

    Trivellato, D.

    2012-01-01

    Systems of systems are coalitions of autonomous and heterogeneous systems that collaborate to achieve a common goal. The component systems of a system of systems often belong to different security domains, which are governed by different authorities (hereafter called parties). Furthermore, systems

  14. Magnetospheric Multiscale (MMS) Mission Attitude Ground System Design

    Science.gov (United States)

    Sedlak, Joseph E.; Superfin, Emil; Raymond, Juan C.

    2011-01-01

    This paper describes the attitude ground system (AGS) design to be used for support of the Magnetospheric MultiScale (MMS) mission. The AGS exists as one component of the mission operations control center. It has responsibility for validating the onboard attitude and accelerometer bias estimates, calibrating the attitude sensors and the spacecraft inertia tensor, and generating a definitive attitude history for use by the science teams. NASA's Goddard Space Flight Center (GSFC) in Greenbelt, Maryland is responsible for developing the MMS spacecraft, for the overall management of the MMS mission, and for mission operations. MMS is scheduled for launch in 2014 for a planned two-year mission. The MMS mission consists of four identical spacecraft flying in a tetrahedral formation in an eccentric Earth orbit. The relatively tight formation, ranging from 10 to 400 km, will provide coordinated observations giving insight into small-scale magnetic field reconnection processes. By varying the size of the tetrahedron and the orbital semi-major axis and eccentricity, and making use of the changing solar phase, this geometry allows for the study of both bow shock and magnetotail plasma physics, including acceleration, reconnection, and turbulence. The mission divides into two phases for science; these phases will have orbit dimensions of l.2xl2 Earth radii in the first phase and l.2x25 Earth radii in the second in order to study the dayside magnetopause and the nightside magnetotail, respectively. The orbital periods are roughly one day and three days for the two mission phases. Each of the four MMS spacecraft will be spin stabilized at 3 revolutions per minute (rpm), with the spin axis oriented near the ecliptic north pole but tipped approximately 2.5 deg towards the Sun line. The main body of each spacecraft will be an eight-sided platform with diameter of 3.4 m and height of 1.2 m. Several booms are attached to this central core: two axial booms of 14.9 m length, two radial

  15. Dynamical systems

    CERN Document Server

    Birkhoff, George D

    1927-01-01

    His research in dynamics constitutes the middle period of Birkhoff's scientific career, that of maturity and greatest power. -Yearbook of the American Philosophical Society The author's great book€¦is well known to all, and the diverse active modern developments in mathematics which have been inspired by this volume bear the most eloquent testimony to its quality and influence. -Zentralblatt MATH In 1927, G. D. Birkhoff wrote a remarkable treatise on the theory of dynamical systems that would inspire many later mathematicians to do great work. To a large extent, Birkhoff was writing about his o

  16. Nuclear systems

    CERN Document Server

    Todreas, Neil E

    2011-01-01

    Principal Characteristics of Power ReactorsIntroductionPower CyclesPrimary Coolant SystemsReactor CoresFuel AssembliesAdvanced Water- and Gas-Cooled Reactors (Generation III And III+)Advanced Thermal and Fast Neutron Spectrum Reactors (Generation IV)ReferencesProblemsThermal Design Principles and ApplicationIntroductionOverall Plant Characteristics Influenced by Thermal Hydraulic ConsiderationsEnergy Production and Transfer ParametersThermal Design LimitsThermal Design MarginFigures of Merit for Core Thermal PerformanceThe Inverted Fuel ArrayThe Equivalent Annulus ApproximationReferencesProble

  17. Videobasierte Systeme

    Science.gov (United States)

    Knoll, Peter

    Videosensoren spielen für Fahrerassistenz systeme eine zentrale Rolle, da sie die Interpretation visueller Informationen (Objektklassifikation) gezielt unterstützen. Im Heckbereich kann die Video sensorik in der einfachsten Variante die ultraschallbasierte Einparkhilfe bei Einpark- und Rangiervorgängen unterstützen. Beim Nachtsichtsystem NightVision wird das mit Infrarotlicht angestrahlte Umfeld vor dem Fahrzeug mit einer Frontkamera aufgenommen und im Fahrzeugcockpit auf einem Display dem Fahrer angezeigt (s. Nachtsichtsysteme). Andere Fahrerassistenzsysteme verarbeiten die Videosignale und generieren daraus gezielt Informationen, die für eigenständige Funktionen (z. B. Spurverlassenswarner) oder aber als Zusatzinformation für andere Funktionen ausgewertet werden (Sensordatenfusion).

  18. Relaxation System

    Science.gov (United States)

    1987-01-01

    Environ Corporation's relaxation system is built around a body lounge, a kind of super easy chair that incorporates sensory devices. Computer controlled enclosure provides filtered ionized air to create a feeling of invigoration, enhanced by mood changing aromas. Occupant is also surrounded by multidimensional audio and the lighting is programmed to change colors, patterns, and intensity periodically. These and other sensory stimulators are designed to provide an environment in which the learning process is stimulated, because research has proven that while an individual is in a deep state of relaxation, the mind is more receptive to new information.

  19. Bearing system

    Science.gov (United States)

    Kapich, Davorin D.

    1987-01-01

    A bearing system includes backup bearings for supporting a rotating shaft upon failure of primary bearings. In the preferred embodiment, the backup bearings are rolling element bearings having their rolling elements disposed out of contact with their associated respective inner races during normal functioning of the primary bearings. Displacement detection sensors are provided for detecting displacement of the shaft upon failure of the primary bearings. Upon detection of the failure of the primary bearings, the rolling elements and inner races of the backup bearings are brought into mutual contact by axial displacement of the shaft.

  20. Propulsion Systems

    Science.gov (United States)

    2011-03-31

    stand.    CV CS x dAvvdVov dt d F   (18-1) Where  denotes density and vx is the velocity in the x-direction. The first term on the...by  but to avoid confusion with  from Eqs. 18-7 to 10, it is denoted k in this formula . Ru is the universal gas constant (8.314472 J/mol K), pe is...Russian Federation Used on Phobos spacecraft as main engines 74 1.03 NTO/ UDMH 13.73-19.61 316-325 Orbital Maneuvering System 1 Aerojet Shuttle

  1. Expert Systems: What Is an Expert System?

    Science.gov (United States)

    Duval, Beverly K.; Main, Linda

    1994-01-01

    Describes expert systems and discusses their use in libraries. Highlights include parts of an expert system; expert system shells; an example of how to build an expert system; a bibliography of 34 sources of information on expert systems in libraries; and a list of 10 expert system shells used in libraries. (Contains five references.) (LRW)

  2. System analysis and design

    International Nuclear Information System (INIS)

    Son, Seung Hui

    2004-02-01

    This book deals with information technology and business process, information system architecture, methods of system development, plan on system development like problem analysis and feasibility analysis, cases for system development, comprehension of analysis of users demands, analysis of users demands using traditional analysis, users demands analysis using integrated information system architecture, system design using integrated information system architecture, system implementation, and system maintenance.

  3. Posting system

    International Nuclear Information System (INIS)

    Hackney, S.

    1983-01-01

    A system for posting hazardous materials into and out of an enclosure, such as a glovebox, through a port in a wall of the enclosure. The port is normally closed by a door which cooperates with a removable end closure, on a container or the like when the latter is presented to and secured at the port. The container is secured in position at the port by means of a rotatable coupling ring. A single interlock ensures that the door cannot be opened in the absence of a container at the port and also that the container cannot be removed from the port when the door is open. In place of the container, a glove secured to a rigid sleeve may be used to enable the operator to perform a work function within the glovebox. (author)

  4. hydrothermal systems

    Directory of Open Access Journals (Sweden)

    L. Bayón

    2002-01-01

    Full Text Available In this paper, we revise the classical formulation of the problem depriving it of the concepts that are superfluous from the mathematical point of view. We observe that a number of power stations can be substituted by a single one that behaves equivalently to the entire set. Proceeding in this way, we obtain a variational formulation in its purest sense (without restrictions. This formulation allows us to employ the theory of calculus of variations to the highest degree. We then calculate the equivalent minimizer in the case where the cost functions are second-order polynomials. We prove that the equivalent minimizer is a second-order polynomial with piece-wise constant coefficients. Moreover, it belongs to the class C1. Finally, we present various examples prompted by real systems and perform the proposed algorithms using Mathematica.

  5. Nonlinear systems

    CERN Document Server

    Palmero, Faustino; Lemos, M; Sánchez-Rey, Bernardo; Casado-Pascual, Jesús

    2018-01-01

    This book presents an overview of the most recent advances in nonlinear science. It provides a unified view of nonlinear properties in many different systems and highlights many  new developments. While volume 1 concentrates on mathematical theory and computational techniques and challenges, which are essential for the study of nonlinear science, this second volume deals with nonlinear excitations in several fields. These excitations can be localized and transport energy and matter in the form of breathers, solitons, kinks or quodons with very different characteristics, which are discussed in the book. They can also transport electric charge, in which case they are known as polarobreathers or solectrons. Nonlinear excitations can influence function and structure in biology, as for example, protein folding. In crystals and other condensed matter, they can modify transport properties, reaction kinetics and interact with defects. There are also engineering applications in electric lattices, Josephson junction a...

  6. Posting system

    International Nuclear Information System (INIS)

    Jones, E.L.

    1983-01-01

    A posting system for the movement of equipment, such as a manipulator, into and out of an enclosure e.g. a cell or glovebox, for toxic or radioactive materials has the manipulator arranged within a collapsible bellows-like container with an end of the container cooperating with a port entry to the enclosure. The collapsible container isolates the manipulator from the environment outside the enclosure and allows the manipulator to enter and leave the contaminated enclosure without breach of the containment. A particular construction of cell for use with radioactive material is described, having a thick wall of shielding material such as concrete provided with a door normally closed by a Pb shutter and having a cylindrical gamma shield block located over the shutter on the exterior of the wall. (author)

  7. Thermodynamic Modeling of Poorly Complexing Metals in Concentrated Electrolyte Solutions: An X-Ray Absorption and UV-Vis Spectroscopic Study of Ni(II) in the NiCl2-MgCl2-H2O System

    Science.gov (United States)

    Zhang, Ning; Brugger, Joël; Etschmann, Barbara; Ngothai, Yung; Zeng, Dewen

    2015-01-01

    Knowledge of the structure and speciation of aqueous Ni(II)-chloride complexes is important for understanding Ni behavior in hydrometallurgical extraction. The effect of concentration on the first-shell structure of Ni(II) in aqueous NiCl2 and NiCl2-MgCl2 solutions was investigated by Ni K edge X-ray absorption (XAS) and UV-Vis spectroscopy at ambient conditions. Both techniques show that no large structural change (e.g., transition from octahedral to tetrahedral-like configuration) occurs. Both methods confirm that the Ni(II) aqua ion (with six coordinated water molecules at R Ni-O = 2.07(2) Å) is the dominant species over the whole NiCl2 concentration range. However, XANES, EXAFS and UV-Vis data show subtle changes at high salinity (> 2 mol∙kg-1 NiCl2), which are consistent with the formation of small amounts of the NiCl+ complex (up to 0.44(23) Cl at a Ni-Cl distance of 2.35(2) Å in 5.05 mol∙kg-1 NiCl2) in the pure NiCl2 solutions. At high Cl:Ni ratio in the NiCl2-MgCl2-H2O solutions, small amounts of [NiCl2]0 are also present. We developed a speciation-based mixed-solvent electrolyte (MSE) model to describe activity-composition relationships in NiCl2-MgCl2-H2O solutions, and at the same time predict Ni(II) speciation that is consistent with our XAS and UV-Vis data and with existing literature data up to the solubility limit, resolving a long-standing uncertainty about the role of chloride complexing in this system. PMID:25885410

  8. Systems engineering simplified

    CERN Document Server

    Cloutier, Robert; Bone, Mary Alice

    2015-01-01

    IntroductionOverviewDiscussion of Common TerminologyThe Case for Systems EngineeringA Brief History of Systems EngineeringSystem ExamplesSummaryThe System Life CycleManaging System Development-The Vee ModelSystem ProductionSystem Utilization and SupportSystem Retirement and DisposalOther Systems Engineering Development ModelsSpiral ModelAgile Model for Systems EngineeringSystem of InterestAbstraction and DecompositionIntegrationDeveloping and Managing RequirementsCyclone Requiremen

  9. NJOY system

    International Nuclear Information System (INIS)

    Gil, Choong Sup; Kim, Jung Do

    1998-01-01

    The NJOY Nuclear Data Processing System is used to convert evaluated nuclear data in ENDF format into forms useful for applications. The NJOY code is a modular computer code designed to read evaluated data in ENDF format, transform the data in various ways, and output the results as libraries designed to be used in various applications. The modules are essentially independent programs, and they communicate with each other using input and output files, plus a very few common variables. The NJOY code can work with neutrons, photons, and charged particles. The evaluated nuclear data are reconstructed to pointwise cross sections from ENDF resonance parameters and interpolation schemes. The pointwise data can be Doppler broadened to the temperatures requested by users. The data in unresolved energy range can be computed to effective self-shielded pointwise cross sections. The cross sections and scattering matrices for free or bound scatterers in the thermal energy range are able to be produced. The self-shielded multigroup cross sections, group-to-group scattering matrices, photon-production matrices, and charged-particle cross sections from pointwise data can be generated for various application codes

  10. Chem systems

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper reports that world styrene demand, paced by a near doubling of combined requirements in East Asia and Oceania, could reach 19.3 million metric tons by 2000, an average growth rate of 3.7%/year. So concludes Chem Systems Inc., Tarrytown, N.Y., in a study of world styrene markets through the end of the century. Pacific Rim styrene production and consumption throughout the 1990s are predicted to make up increasingly larger shares of world markets, while demand and production lag in the U.S. and western Europe. Demand and capacity in other parts of the world will grow in real terms, increasing combined market shares only slightly. Most of the increase will be driven by demand in East Asia and Oceania, where consumption by century's end is expected to increase 4.48 million metric tons from 2.25 million tons in 1991. Meantime, Japan's styrene demand in 2000 is projected at 2.64 million tons, a 500,000 ton increase from 1991 demand but a net market loss of 1.9%

  11. System safety education focused on system management

    Science.gov (United States)

    Grose, V. L.

    1971-01-01

    System safety is defined and characteristics of the system are outlined. Some of the principle characteristics include role of humans in hazard analysis, clear language for input and output, system interdependence, self containment, and parallel analysis of elements.

  12. Systems Biology and Health Systems Complexity in;

    NARCIS (Netherlands)

    Donald Combs, C.; Barham, S.R.; Sloot, P.M.A.

    2016-01-01

    Systems biology addresses interactions in biological systems at different scales of biological organization, from the molecular to the cellular, organ, organism, societal, and ecosystem levels. This chapter expands on the concept of systems biology, explores its implications for individual patients

  13. Airport Information Retrieval System (AIRS) System Design

    Science.gov (United States)

    1974-07-01

    This report presents the system design for a prototype air traffic flow control automation system developed for the FAA's Systems Command Center. The design was directed toward the immediate automation of airport data for use in traffic load predicti...

  14. System specifications for the NDS Dictionary System

    International Nuclear Information System (INIS)

    Attree, P.M.; Smith, P.M.

    1979-09-01

    The NDS Dictionary System is a computerized system for maintaining and distributing the EXFOR dictionaries and for preparing internal versions of these dictionaries for use in the NDS EXFOR System and other NDS systems. This document is an internal manual for the system specifications of the NDS Dictionary System. It includes flow charts, system and program summaries, input and output specifications and file and record descriptions. This manual is updated from time to time when system modifications are made; this is the version of January 1979

  15. Quality management system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mu Sung

    2009-08-15

    This book deals with ISO9001 quality management system which includes summary of this system such as classification of quality, principle of quality management, and definition, requirement and procedure of quality management system, introduction of ISO9001 system like model of ISO9001 quality management system, ISO certificate system, structure of ISO9001 standard, requirement of ISO9001 quality management system, process approach and documentation of system, propel cases of ISO9001 quality management system.

  16. Quality management system

    International Nuclear Information System (INIS)

    Lee, Mu Sung

    2009-08-01

    This book deals with ISO9001 quality management system which includes summary of this system such as classification of quality, principle of quality management, and definition, requirement and procedure of quality management system, introduction of ISO9001 system like model of ISO9001 quality management system, ISO certificate system, structure of ISO9001 standard, requirement of ISO9001 quality management system, process approach and documentation of system, propel cases of ISO9001 quality management system.

  17. A Deep Penetration Problem Calculation Using AETIUS:An Easy Modeling Discrete Ordinates Ṯransport Code UsIng Unstructured Tetrahedral Mesh, Shared Memory Parallel

    Directory of Open Access Journals (Sweden)

    KIM Jong Woon

    2017-01-01

    In this paper, we describe a brief overview of AETIUS and provide numerical results from both AETIUS and a Monte Carlo code, MCNP5, in a deep penetration problem with small detection volumes. The results demonstrate the effectiveness and efficiency of AETIUS for such calculations.

  18. A family of mixed-metal cyanide cubes with alternating octahedral and tetrahedral corners exhibiting a variety of magnetic behaviors including single molecule magnetism.

    Science.gov (United States)

    Schelter, Eric J; Karadas, Ferdi; Avendano, Carolina; Prosvirin, Andrey V; Wernsdorfer, Wolfgang; Dunbar, Kim R

    2007-07-04

    A series of structurally related pseudocubic metal cyanide clusters of Re(II) and 3d metal ions [{MX}4{Re(triphos)(CN)3}4] (M = Mn, Fe, Co, Ni, Zn; X = Cl, I, -OCH3) have been prepared, and their magnetic and electrochemical properties have been probed to evaluate the effect of changing the identity of the 3d metal ion. Electrochemistry of the clusters reveals several rhenium-based oxidation and reduction processes, some of which result in cluster fragmentation. The richest electrochemistry was observed for the iron congener, which exists as the Re(I)/Fe(III) cluster at the resting potential and exhibits six clear one-electron reversible redox couples and two, closely spaced one-electron quasi-reversible processes. The [{MnIICl}4{ReII(triphos)(CN)3}4] complex exhibits single molecule magnetism with a fast tunneling relaxation process observed at H = 0 determined by micro-SQUID magnetization measurements. A comparative evaluation of the magnetic properties across the series reveals that the compounds exhibit antiferromagnetic coupling between the metal ions, except for [{NiIICl}4{ReII(triphos)(CN)3}4] that shows ferromagnetic behavior. Despite the large ground-state spin value of [{NiIICl}4{ReII(triphos)(CN)3}4] (S = 6), only manganese congeners exhibit SMM behavior to 1.8 K.

  19. Understanding the fast phase-change mechanism of tetrahedrally bonded Cu2GeTe3 : Comprehensive analyses of electronic structure and transport phenomena

    Science.gov (United States)

    Kobayashi, Keisuke; Skelton, Jonathan M.; Saito, Yuta; Shindo, Satoshi; Kobata, Masaaki; Fons, Paul; Kolobov, Alexander V.; Elliott, Stephen; Ando, Daisuke; Sutou, Yuji

    2018-05-01

    Cu2GeTe3 (CGT) phase-change material, a promising candidate for advanced fast nonvolatile random-access-memory devices, has a chalcopyritelike structure with s p3 bonding in the crystalline phase; thus, the phase-change (PC) mechanism is considered to be essentially different from that of the standard PC materials (e.g., Ge-Sb-Te) with threefold to sixfold p -like bonding. In order to reveal the PC mechanism of CGT, the electronic structure change due to PC has been investigated by laboratory hard x-ray photoelectron spectroscopy and combined first-principles density-functional theory molecular-dynamics simulations. The valence-band spectra, in both crystalline and amorphous phases, are well simulated by the calculations. An inherent tendency of Te 5 s lone-pair formation and an enhanced participation of Cu 3 d orbitals in the bonding are found to play dominant roles in the PC mechanism. The electrical conductivity of as-deposited films and its change during the PC process is investigated in connection with valence-band spectral changes near the Fermi level. The results are successfully analyzed, based on a model proposed by Davis and Mott for chalcogenide amorphous semiconductors. The results suggest that robustness of the defect-band states against thermal stress is a key to the practical application of this material for memory devices.

  20. Synthesis, crystal structure and electrical properties of the tetrahedral quaternary chalcogenides CuM{sub 2}InTe{sub 4} (M=Zn, Cd)

    Energy Technology Data Exchange (ETDEWEB)

    Nolas, George S., E-mail: gnolas@usf.edu [Department of Physics, University of South Florida, Tampa, FL 33620 (United States); Hassan, M. Shafiq; Dong, Yongkwan [Department of Physics, University of South Florida, Tampa, FL 33620 (United States); Martin, Joshua [Material Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899 (United States)

    2016-10-15

    Quaternary chalcogenides form a large class of materials that continue to be of interest for energy-related applications. Certain compositions have recently been identified as possessing good thermoelectric properties however these materials typically have the kesterite structure type with limited variation in composition. In this study we report on the structural, optical and electrical properties of the quaternary chalcogenides CuZn{sub 2}InTe{sub 4} and CuCd{sub 2}InTe{sub 4} which crystallize in the modified zinc-blende crystal structure, and compare their properties with that of CuZn{sub 2}InSe{sub 4}. These p-type semiconductors have direct band gaps of about 1 eV resulting in relatively high Seebeck coefficient and resistivity values. This work expands on the research into quaternary chalcogenides with new compositions and structure types in order to further the fundamental investigation of multinary chalcogenides for potential thermoelectrics applications. - Graphical abstract: The structural, optical and electrical properties of the quaternary chalcogenides CuZn{sub 2}InTe{sub 4} and CuCd{sub 2}InTe{sub 4} are reported for the first time. The unique crystal structure allows for relatively good electrical transports and therefore potential for thermoelectric applications. - Highlights: • The physical properties of CuZn{sub 2}InTe{sub 4} and CuCd{sub 2}InTe{sub 4} are reported for the first time. • These materials have potential for thermoelectric applications. • Their direct band gaps also suggest potential for photovoltaics applications.

  1. Protecting Information in Systems of Systems

    NARCIS (Netherlands)

    Trivellato, Daniel; Zannone, Nicola; Etalle, Sandro

    2011-01-01

    Systems of Systems (SoS) are dynamic, distributed coalitions of autonomous and heterogeneous systems that collaborate to achieve a common goal. While offering several advantages in terms of scalability and flexibility, the SoS paradigm has a strong impact on system interoperability and on the

  2. A security framework for systems of systems

    NARCIS (Netherlands)

    Trivellato, D.; Zannone, N.; Etalle, S.

    2011-01-01

    Systems of systems consist of a wide variety of dynamic, distributed coalitions of autonomous and heterogeneous systems that collaborate to achieve a common goal. While offering several advantages in terms of scalability and flexibility, this new paradigm has a strong impact on system

  3. A Security Framework for Systems of Systems

    NARCIS (Netherlands)

    Trivellato, Daniel; Zannone, Nicola; Etalle, Sandro

    2011-01-01

    Systems of systems consist of a wide variety of dynamic, distributed coalitions of autonomous and heterogeneous systems that collaborate to achieve a common goal. While offering several advantages in terms of scalability and flexibility, this new paradigm has a strong impact on system

  4. Systems theory of interconnected port contact systems

    NARCIS (Netherlands)

    Eberard, D.; Maschke, B.M.; Schaft, A.J. van der

    2005-01-01

    Port-based network modeling of a large class of complex physical systems leads to dynamical systems known as port-Hamiltonian systems. The key ingredient of any port-Hamiltonian system is a power-conserving interconnection structure (mathematically formalized by the geometric notion of a Dirac

  5. Digital processing data communication systems (bus systems)

    International Nuclear Information System (INIS)

    Fleck, K.

    1980-01-01

    After an introduction to the technology of digital processing data communication systems there are the following chapters: digital communication of processing data in automation technology, the technology of biserial communication, the implementaiton of a bus system, the data transmission of the TDC-2000 system of Honeywell's and the process bus CS 275 in the automation system TELEPERM M of Siemens AG. (WB) [de

  6. Networked control of microgrid system of systems

    Science.gov (United States)

    Mahmoud, Magdi S.; Rahman, Mohamed Saif Ur; AL-Sunni, Fouad M.

    2016-08-01

    The microgrid has made its mark in distributed generation and has attracted widespread research. However, microgrid is a complex system which needs to be viewed from an intelligent system of systems perspective. In this paper, a network control system of systems is designed for the islanded microgrid system consisting of three distributed generation units as three subsystems supplying a load. The controller stabilises the microgrid system in the presence of communication infractions such as packet dropouts and delays. Simulation results are included to elucidate the effectiveness of the proposed control strategy.

  7. D0 Cryo System Control System Autodialer

    Energy Technology Data Exchange (ETDEWEB)

    Urbin, J.; /Fermilab

    1990-04-17

    The DO cryogenic system is controlled by a TI565-PLC based control system. This allows the system to be unmanned when in steady state operation. System experts will need to be contacted when system parameters exceed normal operating points and reach alarm setpoints. The labwide FIRUS system provides one alarm monitor and communication link. An autodialer provides a second and more flexible alarm monitor and communication link. The autodialer monitors contact points in the control system and after receiving indication of an alarm accesses a list of experts which it calls until it receives an acknowledgement. There are several manufacturers and distributors of autodialer systems. This EN explains the search process the DO cryo group used to fmd an autodialer system that fit the cryo system's needs and includes information and specs for the unit we chose.

  8. Superspeed Maglev system Transrapid. System decription

    Energy Technology Data Exchange (ETDEWEB)

    Miller, L [Thyssen Henschel AG,, Maglev Transportation Technology, Muenchen (Germany)

    1996-12-31

    The superspeed maglev system Transrapid is a track-bound transportation system for passengern and priority freight transport. The transrapid trainsets are composed of self-sufficient vehicle section coupled together. The superspeed maglev system Transrapid is capable of revenue operation at speeds of 100 to 500 km/h. Besides the description of the system concept and system characteristics safety and availability are discussed. (HW)

  9. System design specification Brayton Isotope Power System (BIPS) Flight System (FS), and Ground Demonstration System (GDS)

    International Nuclear Information System (INIS)

    1976-01-01

    The system design specification for ground demonstration, development, and flight qualification of a Brayton Isotope Power System (BIPS) is presented. The requirements for both a BIPS conceptual Flight System (FS) and a Ground Demonstration System (GDS) are defined

  10. Situation awareness with systems of systems

    CERN Document Server

    Tretmans, Jan; Borth, Michael

    2013-01-01

    This book discusses various aspects, challenges, and solutions for developing systems-of-systems for situation awareness, using applications in the domain of maritime safety and security.  Topics include advanced, multi-objective visualization methods for situation awareness, stochastic outlier selection, rule-based anomaly detection, an ontology-based event model for semantic reasoning, new methods for semi-automatic generation of adapters bridging communication gaps, security policies for systems-of-systems, trust assessment, and methods to deal with the dynamics of systems-of-systems in run-time monitoring, testing, and diagnosis. Architectural considerations for designing information-centric systems-of-systems such as situation awareness systems, and an integrated demonstrator implementing many of the investigated aspects, complete the book.

  11. System specifications for the NDS EXFOR System

    International Nuclear Information System (INIS)

    Attree, P.M.; Smith, P.M.

    1979-07-01

    EXFOR is the agreed exchange format for the magnetic-tape exchange of nuclear reaction data between national and international nuclear data centres for the benefit of nuclear data users in all countries. The NDS EXFOR System is a computerized system for the storage and retrieval of EXFOR information compiled or received by the IAEA. This document is an internal manual for the system specifications of the NDS EXFOR System. It includes flow charts, system and program summaries, input and output specifications and file and record descriptions. The manual is updated from time to time when system modifications are made

  12. System specifications for the NDS EXFOR System

    Energy Technology Data Exchange (ETDEWEB)

    Attree, P M; Smith, P M

    1982-06-01

    EXFOR is the agreed exchange format for the magnetic-tape exchange of nuclear reaction data between national and international nuclear data centers for the benefit of nuclear data users in all countries. The NDS EXFOR System is a computerized system for the storage and retrieval of EXFOR information compiled or received of the IAEA. This document is an internal manual for the system specifications of the NDS EXFOR System. It includes flow charts, system and program summaries, input and output specifications and file and record descriptions. The manual is updated from time to time when system modifications are made; the first version was issued in July 1979. (author)

  13. Computer System Design System-on-Chip

    CERN Document Server

    Flynn, Michael J

    2011-01-01

    The next generation of computer system designers will be less concerned about details of processors and memories, and more concerned about the elements of a system tailored to particular applications. These designers will have a fundamental knowledge of processors and other elements in the system, but the success of their design will depend on the skills in making system-level tradeoffs that optimize the cost, performance and other attributes to meet application requirements. This book provides a new treatment of computer system design, particularly for System-on-Chip (SOC), which addresses th

  14. Smart electromechanical systems the central nervous system

    CERN Document Server

    Kurbanov, Vugar

    2017-01-01

    This book describes approaches to solving the problems of developing the central nervous system of robots (CNSR) based on smart electromechanical systems (SEMS) modules, principles of construction of the various modules of the central nervous system and variants of mathematical software CNSR in control systems for intelligent robots. It presents the latest advances in theory and practice at the Russian Academy of Sciences. Developers of intelligent robots to solve modern problems in robotics are increasingly addressing the use of the bionic approach to create robots that mimic the complexity and adaptability of biological systems. These have smart electromechanical system (SEMS), which are used in various cyber-physical systems (CPhS), and allow the functions of calculation, control, communications, information storage, monitoring, measurement and control of parameters and environmental parameters to be integrated. The behavior of such systems is based on the information received from the central nervous syst...

  15. Multiobjective Collaborative Optimization of Systems of Systems

    National Research Council Canada - National Science Library

    Wolf, Robert A

    2005-01-01

    ...; in other words an inefficient design of the system of systems. This thesis examines the simultaneous design of several ships using the sea base concept as an example application of a network of ships working together...

  16. Situation Awareness with Systems of Systems

    NARCIS (Netherlands)

    Laar, P. van de; Tretmans, J.; Borth, M.

    2013-01-01

    This book discusses various aspects, challenges, and solutions for developing systems-of-systems for situation awareness, using applications in the domain of maritime safety and security. Topics include advanced, multi-objective visualization methods for situation awareness, stochastic outlier

  17. Linking Political Systems and War Systems

    DEFF Research Database (Denmark)

    Harste, Gorm

    2009-01-01

    Decisive parts of the Western political system have demonstrated a seemingly surprising misinterpretation of military might. As Madelaine Albright has suggested, the mighty perceived themselves as "almighty". Political power seems to have invested in instrumental coercive power relations and found...... military coercion to be the appropriate mean. Using the system theory and the theory of systemic risks displayed by the German sociologist Niklas Luhmann the article demonstrates how military systems due to their own autonomy and autopoiesis do not fit into the idea of political government....... The Clausewitzian ideal of a political system that could continue its power games by means of war was moderated by Clausewitz' own analysis of "friction". How can a political system be so blind towards the possibilities of another system? What are the risks of systemic blind spots? The argument of the paper...

  18. Designing information systems

    CERN Document Server

    Blethyn, Stanley G

    2014-01-01

    Designing Information Systems focuses on the processes, methodologies, and approaches involved in designing information systems. The book first describes systems, management and control, and how to design information systems. Discussions focus on documents produced from the functional construction function, users, operators, analysts, programmers and others, process management and control, levels of management, open systems, design of management information systems, and business system description, partitioning, and leveling. The text then takes a look at functional specification and functiona

  19. Cognitive Medical Multiagent Systems

    OpenAIRE

    Barna Iantovics

    2010-01-01

    The development of efficient and flexible agent-based medical diagnosis systems represents a recent research direction. Medical multiagent systems may improve the efficiency of traditionally developed medical computational systems, like the medical expert systems. In our previous researches, a novel cooperative medical diagnosis multiagent system called CMDS (Contract Net Based Medical Diagnosis System) was proposed. CMDS system can solve flexibly a large variety of medical diagnosis problems...

  20. Non linear system become linear system

    Directory of Open Access Journals (Sweden)

    Petre Bucur

    2007-01-01

    Full Text Available The present paper refers to the theory and the practice of the systems regarding non-linear systems and their applications. We aimed the integration of these systems to elaborate their response as well as to highlight some outstanding features.

  1. System Design of the SWRL Financial System.

    Science.gov (United States)

    Ikeda, Masumi

    To produce various management and accounting reports in order to maintain control of SWRL (Southwest Regional Laboratory) operational and financial activities, a computer-based SWRL financial system was developed. The system design is outlined, and various types of system inputs described. The kinds of management and accounting reports generated…

  2. Triggering system innovation in agricultural innovation systems

    NARCIS (Netherlands)

    Turner, James A.; Williams, Tracy; Nicholas, Graeme; Foote, Jeff; Rijswijk, Kelly; Barnard, Tim; Beechener, Sam; Horita, Akiko

    2017-01-01

    This article describes a process for stimulating engagement among change agents to develop a shared understanding of systemic problems in the agricultural innovation system (AIS), challenge prevalent institutional logics and identify actions they might undertake to stimulate system innovation.

  3. Port contact systems for irreversible thermodynamical systems

    NARCIS (Netherlands)

    Eberard, D.; Maschke, B.M.; Schaft, A.J. van der

    2005-01-01

    In this paper we propose a definition of control contact systems, generalizing input-output Hamiltonian systems, to cope with models arising from irreversible Thermodynamics. We exhibit a particular subclass of these systems, called conservative, that leaves invariant some Legendre submanifold (the

  4. Modeling learning technology systems as business systems

    NARCIS (Netherlands)

    Avgeriou, Paris; Retalis, Symeon; Papaspyrou, Nikolaos

    2003-01-01

    The design of Learning Technology Systems, and the Software Systems that support them, is largely conducted on an intuitive, ad hoc basis, thus resulting in inefficient systems that defectively support the learning process. There is now justifiable, increasing effort in formalizing the engineering

  5. General Systems Theory and Instructional Systems Design.

    Science.gov (United States)

    Salisbury, David F.

    1990-01-01

    Describes basic concepts in the field of general systems theory (GST) and identifies commonalities that exist between GST and instructional systems design (ISD). Models and diagrams that depict system elements in ISD are presented, and two matrices that show how GST has been used in ISD literature are included. (11 references) (LRW)

  6. Expert systems in process control systems

    International Nuclear Information System (INIS)

    Wittig, T.

    1987-01-01

    To illustrate where the fundamental difference between expert systems in classical diagnosis and in industrial control lie, the work of process control instrumentation is used as an example for the job of expert systems. Starting from the general process of problem-solving, two classes of expert systems can be defined accordingly. (orig.) [de

  7. Expert Systems for auditing management information systems

    Directory of Open Access Journals (Sweden)

    Gheroghe Popescu

    2007-05-01

    Full Text Available Expert systems are built with the help of: specialised programming languages or expert system generators (shell. But this structure was reached after tens of years of work and research, because expert systems are nothing but pragmatic capitalisation of the results of research carried out in artificial intelligence and theory of knowledge.

  8. Psychology of system design

    CERN Document Server

    Meister, D

    2014-01-01

    This is a book about systems, including: systems in which humans control machines; systems in which humans interact with humans and the machine component is relatively unimportant; systems which are heavily computerized and those that are not; and governmental, industrial, military and social systems. The book deals with both traditional systems like farming, fishing and the military, and with systems just now tentatively emerging, like the expert and the interactive computer system. The emphasis is on the system concept and its implications for analysis, design and evaluation of these many di

  9. Biomedical signals and systems

    CERN Document Server

    Tranquillo, Joseph V

    2013-01-01

    Biomedical Signals and Systems is meant to accompany a one-semester undergraduate signals and systems course. It may also serve as a quick-start for graduate students or faculty interested in how signals and systems techniques can be applied to living systems. The biological nature of the examples allows for systems thinking to be applied to electrical, mechanical, fluid, chemical, thermal and even optical systems. Each chapter focuses on a topic from classic signals and systems theory: System block diagrams, mathematical models, transforms, stability, feedback, system response, control, time

  10. Operating System Security

    CERN Document Server

    Jaeger, Trent

    2008-01-01

    Operating systems provide the fundamental mechanisms for securing computer processing. Since the 1960s, operating systems designers have explored how to build "secure" operating systems - operating systems whose mechanisms protect the system against a motivated adversary. Recently, the importance of ensuring such security has become a mainstream issue for all operating systems. In this book, we examine past research that outlines the requirements for a secure operating system and research that implements example systems that aim for such requirements. For system designs that aimed to

  11. Systems Measures of Water Distribution System Resilience

    Energy Technology Data Exchange (ETDEWEB)

    Klise, Katherine A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Murray, Regan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Walker, La Tonya Nicole [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

    Resilience is a concept that is being used increasingly to refer to the capacity of infrastructure systems to be prepared for and able to respond effectively and rapidly to hazardous events. In Section 2 of this report, drinking water hazards, resilience literature, and available resilience tools are presented. Broader definitions, attributes and methods for measuring resilience are presented in Section 3. In Section 4, quantitative systems performance measures for water distribution systems are presented. Finally, in Section 5, the performance measures and their relevance to measuring the resilience of water systems to hazards is discussed along with needed improvements to water distribution system modeling tools.

  12. Manager's assistant systems for space system planning

    Science.gov (United States)

    Bewley, William L.; Burnard, Robert; Edwards, Gary E.; Shoop, James

    1992-01-01

    This paper describes a class of knowledge-based 'assistant' systems for space system planning. Derived from technology produced for the DARPA/USAF Pilot's Associate program, these assistant systems help the human planner by doing the bookkeeping to maintain plan data and executing the procedures and heuristics currently used by the human planner to define, assess, diagnose, and revise plans. Intelligent systems for Space Station Freedom assembly sequence planning and Advanced Launch System modeling will be presented as examples. Ongoing NASA-funded work on a framework supporting the development of such tools will also be described.

  13. Lighting system with thermal management system

    Science.gov (United States)

    Arik, Mehmet; Weaver, Stanton; Stecher, Thomas; Seeley, Charles; Kuenzler, Glenn; Wolfe, Jr., Charles; Utturkar, Yogen; Sharma, Rajdeep; Prabhakaran, Satish; Icoz, Tunc

    2013-05-07

    Lighting systems having unique configurations are provided. For instance, the lighting system may include a light source, a thermal management system and driver electronics, each contained within a housing structure. The light source is configured to provide illumination visible through an opening in the housing structure. The thermal management system is configured to provide an air flow, such as a unidirectional air flow, through the housing structure in order to cool the light source. The driver electronics are configured to provide power to each of the light source and the thermal management system.

  14. EPICS based DAQ system

    International Nuclear Information System (INIS)

    Cheng Weixing; Chen Yongzhong; Zhou Weimin; Ye Kairong; Liu Dekang

    2002-01-01

    EPICS is the most popular developing platform to build control system and beam diagnostic system in modern physics experiment facilities. An EPICS based data acquisition system was built in Redhat 6.2 operation system. The system is successfully used in the beam position monitor mapping, it improves the mapping process a lot

  15. Autonomous photovoltaic lighting system

    OpenAIRE

    Hafez, Ahmed A. A.; Montesinos Miracle, Daniel; Sudrià Andreu, Antoni

    2012-01-01

    This paper introduces a comparison between the conventional and Photovoltaic (PV) lighting systems. A simple sizing procedure for a PV stand-alone system was advised. The paper also proposes a novel PV lighting system. The proposed system is simple, compact and reliable. The system operation was investigated by thoroughly mathematical and simulation work.

  16. FFTF control system experience

    International Nuclear Information System (INIS)

    Warrick, R.P.

    1981-01-01

    The FFTF control systems provide control equipment for safe and efficient operation of the plant. For convenience, these systems will be divided into three parts for discussions: (1) Plant Protection System (PPS); (2) Plant Control System (PCS); and (3) General Observations. Performance of each of these systems is discussed

  17. Automatic control systems engineering

    International Nuclear Information System (INIS)

    Shin, Yun Gi

    2004-01-01

    This book gives descriptions of automatic control for electrical electronics, which indicates history of automatic control, Laplace transform, block diagram and signal flow diagram, electrometer, linearization of system, space of situation, state space analysis of electric system, sensor, hydro controlling system, stability, time response of linear dynamic system, conception of root locus, procedure to draw root locus, frequency response, and design of control system.

  18. MEA vacuum system

    International Nuclear Information System (INIS)

    Stroo, R.; Schwebke, H.; Heine, E.

    1984-01-01

    This report describes construction and operation of the MEA vacuum system of NIKHEF (Netherlands). First, the klystron vacuum system, beam transport system, diode pump and a triode pump are described. Next, the isolation valve and the fast valves of the vacuum system are considered. Measuring instruments, vacuum system commands and messages of failures are treated in the last chapter. (G.J.P.)

  19. From systems biology to systems biomedicine.

    Science.gov (United States)

    Antony, Paul M A; Balling, Rudi; Vlassis, Nikos

    2012-08-01

    Systems Biology is about combining theory, technology, and targeted experiments in a way that drives not only data accumulation but knowledge as well. The challenge in Systems Biomedicine is to furthermore translate mechanistic insights in biological systems to clinical application, with the central aim of improving patients' quality of life. The challenge is to find theoretically well-chosen models for the contextually correct and intelligible representation of multi-scale biological systems. In this review, we discuss the current state of Systems Biology, highlight the emergence of Systems Biomedicine, and highlight some of the topics and views that we think are important for the efficient application of Systems Theory in Biomedicine. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Mapping biological systems to network systems

    CERN Document Server

    Rathore, Heena

    2016-01-01

    The book presents the challenges inherent in the paradigm shift of network systems from static to highly dynamic distributed systems – it proposes solutions that the symbiotic nature of biological systems can provide into altering networking systems to adapt to these changes. The author discuss how biological systems – which have the inherent capabilities of evolving, self-organizing, self-repairing and flourishing with time – are inspiring researchers to take opportunities from the biology domain and map them with the problems faced in network domain. The book revolves around the central idea of bio-inspired systems -- it begins by exploring why biology and computer network research are such a natural match. This is followed by presenting a broad overview of biologically inspired research in network systems -- it is classified by the biological field that inspired each topic and by the area of networking in which that topic lies. Each case elucidates how biological concepts have been most successfully ...

  1. Natural gels: crystal-chemistry of short range ordered components in Al, Fe, and Si systems

    International Nuclear Information System (INIS)

    Ildefonse, Ph.; Calas, G.

    1997-01-01

    In this review, the most important inorganic natural gels are presented: opal, aluminosilicate (allophanes) and hydrous iron oxides and silicates. It is demonstrated that natural gels are ordered at the atomic scale. In allophanes, Al is distributed between octahedral and tetrahedral sites. The amount of Al increases as Al/Si ratio decreases. Si-rich allophane have a local structure around Al and Si very different of that is known in kaolinite or halloysite. Transformation of Si-rich allophanes to crystallized minerals implies dissolution-recrystallization processes. On the contrary, in iron silicate with Fe/Si = 0.72, Si and Fe environments are close to those found in nontronite. The gel transformation to Fe-smectite may occur by long range ordering during ageing. In ferric silicate gels, the similarity of local structure around Fe in poorly ordered precursors and what is known in crystallized minerals suggests a solid transformation during ageing. This difference between iron and aluminium is mainly due to the ability of Al to enter both tetrahedral and octahedral sites, while the affinity of iron for octahedral sites is higher at low temperature

  2. Bi2O3–CuO–P2O5 system: Two novel compounds built from the intergrowths oxocentered polycationic 1D-ribbons

    International Nuclear Information System (INIS)

    Colmont, Marie; Endara, Diana; Aliev, Almaz; Terryn, Christine; Huvé, Marielle; Mentré, Olivier

    2013-01-01

    Single crystals of two novel bismuth copper oxyphosphates were grown from a unique melt. They have been structurally characterized by means of single crystal X-Ray Diffraction (XRD). Bi 29.4 Cu 9.29 O 32 (PO 4 ) 16 Cu 2.63 (1) is orthorhombic, space group Pca2 1 , a=33.0549(2)A, b=11.6991(4)A and c=5.2902(2)A, R 1 =0.059 and wR 2 =0.061. Bi 37.2 Cu 18.8 O 44 (PO 4 ) 24 Cu 5 (2) is orthorhombic, space group Pna2 1 , a=11.6010(3)A, b=47.4384(5)A and c=5.267(2)A, R 1 =0.0940 and wR 2 =0.0981. Both compounds are formed of similar 1D building units (BUs) organized into two different 3D regular intergrowths mediated by phosphate groups. Here, the so-called 1D-BUs are infinite ribbons formed by edge-sharing O(Bi,M) 4 tetrahedra with n=4 and n=3 tetrahedra-wide units. Both compounds were analyzed from the viewpoint of their relationship with the parent δ-Bi 2 O 3 fluorite-like structure, where phosphorus atoms substitutes for some Bi sites. A non-exhaustive review of the related structural types is given. We have checked by second harmonic generacy (SHG) microscopy that the two non-centrosymmetric structures (despite polar subunits) lead to SHG before the samples are irreversibly damaged. - Graphical abstract: This paper reports the crystal structure of two new bismuth oxophosphate compounds. Both are built on the association of n=3 and 4 building unit ribbons surrounded by isolated PO4 tetrahedra and tunnels hosting Cu 2+ cations. They come in addition to the numerous Bi-based compounds already pointed out. Once more, this is the proof of the richness of this crystal system. - Highlights: • Two new bismuth oxophosphates were synthesized. • Crystal structure were solved thanks to single crystal X-Ray diffraction. • They show two different associations of n=3 and 4 ribbons built on [O,(Bi,M) 4 ] tetrahedral sharing edges and surrounded by isolated PO4 groups. • SHG microscopy confirm the NCS character of both compounds. • The family of bismuth oxophosphate

  3. Effect of lanthanide contraction on the mixed polyamine systems Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien): Syntheses and characterizations of lanthanide complexes with a tetraelenidoantimonate ligand

    International Nuclear Information System (INIS)

    Zhao Jing; Liang Jingjing; Pan Yingli; Zhang Yong; Jia Dingxian

    2011-01-01

    Mixed polyamine systems Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien) (Ln=lanthanide, en=ethylenediamine, dien=diethylenetriamine, trien=triethylenetetramine) were investigated under solvothermal conditions, and novel mixed-coordinated lanthanide(III) complexes [Ln(en) 2 (dien)(η 2 -SbSe 4 )] (Ln=Ce(1a), Nd(1b)), [Ln(en) 2 (dien)(SbSe 4 )] (Ln=Sm(2a), Gd(2b), Dy(2c)), [Ln(en)(trien)(μ-η 1 ,η 2 -SbSe 4 )] ∞ (Ln=Ce(3a), Nd(3b)) and [Sm(en)(trien)(η 2 -SbSe 4 )] (4a) were prepared. Two structural types of lanthanide selenidoantimonates were obtained across the lanthanide series in both en+dien and en+trien systems. The tetrahedral anion [SbSe 4 ] 3- acts as a monodentate ligand mono-SbSe 4 , a bidentate chelating ligand η 2 -SbSe 4 or a tridentate bridging ligand μ-η 1 ,η 2 -SbSe 4 to the lanthanide(III) center depending on the Ln 3+ ions and the mixed ethylene polyamines, indicating the effect of lanthanide contraction on the structures of the lanthanide(III) selenidoantimonates. The lanthanide selenidoantimonates exhibit semiconducting properties with E g between 2.08 and 2.51 eV. - Graphical Abstract: Two structural types of lanthanide(III) selenidoantimonates are formed in both en-dien and en-trien mixed polyamines across lanthanide series, indicating the lanthanide contraction effect on the structures of the lanthanide(III) selenidoantimonates. Highlights: → Two structural types of lanthanide selenidoantimonates are prepared across the lanthanide series in both Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien) systems. → The [SbSe 4 ] 3- anion acts as a mono-SbSe 4 , a η 2 -SbSe 4 or a μ-η 1 ,η 2 -SbSe 4 ligand to the Ln 3+ ions. → The soft base ligand [SbSe 4 ] 3- can be controlled to coordinate to the Ln 3+ ions with en+dien and en+trien as co-ligands.

  4. Synthesis, structure and optical properties of thin films from GeS{sub 2}–In{sub 2}S{sub 3} system deposited by thermal co-evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Todorov, R., E-mail: rossen@iomt.bas.bg [Institute of Optical Materials and Technologies “Acad. J. Malinowski”, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 109, 1113 Sofia (Bulgaria); Petkov, K. [Institute of Optical Materials and Technologies “Acad. J. Malinowski”, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 109, 1113 Sofia (Bulgaria); Kincl, M. [Institute of Macromolecular Chemistry of Czech Academy of Science, Heyrovsky sq. 2, 162 06 Prague 6 (Czech Republic); Černošková, E. [Faculty of Chemical Technology, University of Pardubice, Studentská 84, 532 10 Pardubice (Czech Republic); Vlček, Mil.; Tichý, L. [Institute of Macromolecular Chemistry of Czech Academy of Science, Heyrovsky sq. 2, 162 06 Prague 6 (Czech Republic)

    2014-05-02

    This paper deals with the properties of the glasses and thin films from multi-component chalcogenide prepared by co-evaporation technique. The thin chalcogenide layers from GeS{sub 2}–In{sub 2}S{sub 3} system were deposited by thermal co-evaporation of GeS{sub 2} and In{sub 2}S{sub 3}. Using X-ray microanalysis it was found that the film compositions are closed to the expected ones. X-ray diffraction analysis shows that the thin films deposited by co-evaporation are amorphous. The refractive index, n and the optical band gap, E{sub g}{sup opt} were calculated from the transmittance and reflectance spectra. The thin film's structure was investigated by infrared spectroscopy. It was found that the photo-induced optical changes decrease with increase of indium content while significant thermo-induced changes in the optical properties and structure were observed at 14 at.% indium. The infrared spectra demonstrated high transmittance of the thin films in the range 4000–500 cm{sup −1}. The far-infrared spectra indicated that the indium participates in the glass network of the layers from Ge–S–In system in four coordinated InS{sub 4/2}{sup −} tetrahedral and six-coordinated InS{sub 6/2}{sup 3−} octahedral units. The changes in infrared spectra after annealing of the thin films evidence an increase of population of ethane-like S{sub 3}Ge–GeS{sub 3} units and/or structural or phase change of indium contain units. - Highlights: • The thin layers from GeS{sub 2}–In{sub 2}S{sub 3} system were deposited by thermal co-evaporation. • The photo-induced optical changes decrease with increase of indium content. • The thermo-induced changes in the optical properties and structure were investigated. • The structure of the thin films was investigated by infrared spectroscopy.

  5. Environmental Management System

    Science.gov (United States)

    Goals Recycling Green Purchasing Pollution Prevention Reusing Water Resources Environmental Management Stewardship » Environmental Protection » Environmental Management System Environmental Management System An Environmental Management System is a systematic method for assessing mission activities, determining the

  6. System floorplanning optimization

    KAUST Repository

    Browning, David W.; Elansary, Ayman; Shalaby, Mohamed

    2012-01-01

    Notebook and Laptop Original Equipment Manufacturers (OEMs) place great emphasis on creating unique system designs to differentiate themselves in the mobile market. These systems are developed from the 'outside in' with the focus on how the system

  7. Connected motorcycle system performance.

    Science.gov (United States)

    2016-01-15

    This project characterized the performance of Connected Vehicle Systems (CVS) on motorcycles based on two key components: global positioning and wireless communication systems. Considering that Global Positioning System (GPS) and 5.9 GHz Dedicated Sh...

  8. Antiskid braking system

    Science.gov (United States)

    Pazdera, J. S.

    1974-01-01

    Published report describes analytical development and simulation of braking system. System prevents wheels from skidding when brakes are applied, significantly reducing stopping distance. Report also presents computer simulation study on system as applied to aircraft.

  9. Bridge Management Systems

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper bridge management systems are discussed with special emphasis on management systems for reinforced concrete bridges. Management systems for prestressed concrete bridges, steel bridges, or composite bridges can be developed in a similar way....

  10. TWRSview system requirements specification

    International Nuclear Information System (INIS)

    Caldwell, J.A.; Lee, A.K.

    1995-12-01

    This document provides the system requirements specification for the TWRSview software system. The TWRSview software system is being developed to integrate electronic data supporting the development of the TWRS technical baseline

  11. Calo trigger acquisition system

    CERN Multimedia

    Franchini, Matteo

    2016-01-01

    Calo trigger acquisition system - Evolution of the acquisition system from a multiple boards system (upper, orange cables) to a single board one (below, light blue cables) where all the channels are collected in a single board.

  12. Lungs and Respiratory System

    Science.gov (United States)

    ... Videos for Educators Search English Español Lungs and Respiratory System KidsHealth / For Parents / Lungs and Respiratory System ... ll have taken at least 600 million breaths. Respiratory System Basics All of this breathing couldn't ...

  13. The Trinity System

    Energy Technology Data Exchange (ETDEWEB)

    Archer, Billy Joe [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vigil, Benny Manuel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-13

    This paper describes the Trinity system, the first ASC Advanced Technology System (ATS-1). We describe the Trinity procurement timeline, the ASC computing strategy, the Trinity specific mission needs, and the Trinity system specifications.

  14. Pneumatic transfer systems

    International Nuclear Information System (INIS)

    Bichler, H.; Boeck, H.; Hammer, J.; Buchtela, K.

    1988-11-01

    A pneumatic transfer system for research reactors, including a sample changer system and to be used for neutron activation analysis, is described. The system can be obtained commercially from the Atominstitut. 2 figs. (qui)

  15. Immune System Quiz

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Quiz: Immune System KidsHealth / For Kids / Quiz: Immune System Print How much do you know about your immune system? Find out by taking this quiz! About Us ...

  16. System floorplanning optimization

    KAUST Repository

    Browning, David W.; Ansary, Ayman M. El; Shalaby, Mohamed

    2013-01-01

    Notebook and Laptop Original Equipment Manufacturers (OEMs) place great emphasis on creating unique system designs to differentiate themselves in the mobile market. These systems are developed from the 'outside in' with the focus on how the system

  17. Autonomic Nervous System Disorders

    Science.gov (United States)

    Your autonomic nervous system is the part of your nervous system that controls involuntary actions, such as the beating of your heart ... breathing and swallowing Erectile dysfunction in men Autonomic nervous system disorders can occur alone or as the result ...

  18. Central Nervous System Vasculitis

    Science.gov (United States)

    ... of Vasculitis / Central Nervous System (CNS) Vasculitis Central Nervous System (CNS) Vasculitis Swap out your current Facebook Profile ... Facebook personal page. Replace with this image. Central nervous system (CNS) vasculitis is inflammation of blood vessel walls ...

  19. Wind energy systems

    Science.gov (United States)

    Stewart, H. J.

    1978-01-01

    A discussion on wind energy systems involved with the DOE wind energy program is presented. Some of the problems associated with wind energy systems are discussed. The cost, efficiency, and structural design of wind energy systems are analyzed.

  20. System Software 7 Macintosh

    CERN Multimedia

    1991-01-01

    System 7 is a single-user graphical user interface-based operating system for Macintosh computers and was part of the classic Mac OS line of operating systems. It was introduced on May 13, 1991, by Apple Computer. It succeeded System 6, and was the main Macintosh operating system until it was succeeded by Mac OS 8 in 1997. Features added with the System 7 release included virtual memory, personal file sharing, QuickTime, QuickDraw 3D, and an improved user interface. This is the first real major evolution of the Macintosh system, bringing a significant improvement in the user interface, improved stability and many new features such as the ability to use multiple applications at the same time. "System 7" is the last operating system name of the Macintosh that contains the word "system". Macintosh operating systems were later called "Mac OS" (for Macintosh Operating System).

  1. Marketing reporting system

    OpenAIRE

    Hanić Hasan M.

    2004-01-01

    The main components of a developed and good organized marketing information system are: internal reporting system, marketing reporting system, market research system and analytical marketing system. Marketing reporting system provides data and information about changes in business and micro marketing environment. This component of MIS ensures that marketing managers are up-to-date with what is going on, and to be informed about changes in company marketing environment.

  2. Marketing reporting system

    Directory of Open Access Journals (Sweden)

    Hanić Hasan M.

    2004-01-01

    Full Text Available The main components of a developed and good organized marketing information system are: internal reporting system, marketing reporting system, market research system and analytical marketing system. Marketing reporting system provides data and information about changes in business and micro marketing environment. This component of MIS ensures that marketing managers are up-to-date with what is going on, and to be informed about changes in company marketing environment.

  3. Propulsion Systems Panel deliberations

    Science.gov (United States)

    Bianca, Carmelo J.; Miner, Robert; Johnston, Lawrence M.; Bruce, R.; Dennies, Daniel P.; Dickenson, W.; Dreshfield, Robert; Karakulko, Walt; Mcgaw, Mike; Munafo, Paul M.

    1993-01-01

    The Propulsion Systems Panel was established because of the specialized nature of many of the materials and structures technology issues related to propulsion systems. This panel was co-chaired by Carmelo Bianca, MSFC, and Bob Miner, LeRC. Because of the diverse range of missions anticipated for the Space Transportation program, three distinct propulsion system types were identified in the workshop planning process: liquid propulsion systems, solid propulsion systems and nuclear electric/nuclear thermal propulsion systems.

  4. Small test SDHW systems

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    1999-01-01

    Three small test SDHW systems was tested in a laboratory test facility.The three SDHW systems where all based on the low flow principe and a mantle tank but the design of the systems where different.......Three small test SDHW systems was tested in a laboratory test facility.The three SDHW systems where all based on the low flow principe and a mantle tank but the design of the systems where different....

  5. Battery systems engineering

    CERN Document Server

    Rahn, Christopher D

    2012-01-01

    A complete all-in-one reference on the important interdisciplinary topic of Battery Systems Engineering Focusing on the interdisciplinary area of battery systems engineering, this book provides the background, models, solution techniques, and systems theory that are necessary for the development of advanced battery management systems. It covers the topic from the perspective of basic electrochemistry as well as systems engineering topics and provides a basis for battery modeling for system engineering of electric and hybrid electric vehicle platforms. This original

  6. Gas transfer system

    International Nuclear Information System (INIS)

    Oberlin, J.C.; Frick, G.; Kempfer, C.; North, C.

    1988-09-01

    The state of work on the Vivitron gas transfer system and the system functions are summarized. The system has to: evacuate the Vivitron reservoir; transfer gas from storage tanks to the Vivitron; recirculate gas during operation; transfer gas from the Vivitron to storage tanks; and assure air input. The system is now being installed. Leak alarms are given by SF6 detectors, which set off a system of forced ventilation. Another system continuously monitors the amount of SF6 in the tanks [fr

  7. Cognitive Medical Multiagent Systems

    Directory of Open Access Journals (Sweden)

    Barna Iantovics

    2010-01-01

    Full Text Available The development of efficient and flexible agent-based medical diagnosis systems represents a recent research direction. Medical multiagent systems may improve the efficiency of traditionally developed medical computational systems, like the medical expert systems. In our previous researches, a novel cooperative medical diagnosis multiagent system called CMDS (Contract Net Based Medical Diagnosis System was proposed. CMDS system can solve flexibly a large variety of medical diagnosis problems. This paper analyses the increased intelligence of the CMDS system, which motivates its use for different medical problem’s solving.

  8. Airports Geographic Information System -

    Data.gov (United States)

    Department of Transportation — The Airports Geographic Information System maintains the airport and aeronautical data required to meet the demands of the Next Generation National Airspace System....

  9. Aeronautical Information System -

    Data.gov (United States)

    Department of Transportation — The Aeronautical Information System (AIS) is a leased weather automated system that provides a means of collecting and distributing aeronautical weather information...

  10. Credit Management System

    Data.gov (United States)

    US Agency for International Development — Credit Management System. Outsourced Internet-based application. CMS stores and processes data related to USAID credit programs. The system provides information...

  11. Control system design method

    Science.gov (United States)

    Wilson, David G [Tijeras, NM; Robinett, III, Rush D.

    2012-02-21

    A control system design method and concomitant control system comprising representing a physical apparatus to be controlled as a Hamiltonian system, determining elements of the Hamiltonian system representation which are power generators, power dissipators, and power storage devices, analyzing stability and performance of the Hamiltonian system based on the results of the determining step and determining necessary and sufficient conditions for stability of the Hamiltonian system, creating a stable control system based on the results of the analyzing step, and employing the resulting control system to control the physical apparatus.

  12. Neural Systems Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — As part of the Electrical and Computer Engineering Department and The Institute for System Research, the Neural Systems Laboratory studies the functionality of the...

  13. Integrated Systems Health Management for Intelligent Systems

    Science.gov (United States)

    Figueroa, Fernando; Melcher, Kevin

    2011-01-01

    The implementation of an integrated system health management (ISHM) capability is fundamentally linked to the management of data, information, and knowledge (DIaK) with the purposeful objective of determining the health of a system. It is akin to having a team of experts who are all individually and collectively observing and analyzing a complex system, and communicating effectively with each other in order to arrive at an accurate and reliable assessment of its health. In this paper, concepts, procedures, and approaches are presented as a foundation for implementing an intelligent systems ]relevant ISHM capability. The capability stresses integration of DIaK from all elements of a system. Both ground-based (remote) and on-board ISHM capabilities are compared and contrasted. The information presented is the result of many years of research, development, and maturation of technologies, and of prototype implementations in operational systems.

  14. System Analysis and Risk Assessment (SARA) system

    International Nuclear Information System (INIS)

    Krantz, E.A.; Russell, K.D.; Stewart, H.D.; Van Siclen, V.S.

    1986-01-01

    Utilization of Probabilistic Risk Assessment (PRA) related information in the day-to-day operation of plant systems has, in the past, been impracticable due to the size of the computers needed to run PRA codes. This paper discusses a microcomputer-based database system which can greatly enhance the capability of operators or regulators to incorporate PRA methodologies into their routine decision making. This system is called the System Analysis and Risk Assessment (SARA) system. SARA was developed by EG and G Idaho, Inc. at the Idaho National Engineering Laboratory to facilitate the study of frequency and consequence analyses of accident sequences from a large number of light water reactors (LWRs) in this country. This information is being amassed by several studies sponsored by the United States Nuclear Regulatory Commission (USNRC). To meet the need of portability and accessibility, and to perform the variety of calculations necessary, it was felt that a microcomputer-based system would be most suitable

  15. Systems engineering for very large systems

    Science.gov (United States)

    Lewkowicz, Paul E.

    Very large integrated systems have always posed special problems for engineers. Whether they are power generation systems, computer networks or space vehicles, whenever there are multiple interfaces, complex technologies or just demanding customers, the challenges are unique. 'Systems engineering' has evolved as a discipline in order to meet these challenges by providing a structured, top-down design and development methodology for the engineer. This paper attempts to define the general class of problems requiring the complete systems engineering treatment and to show how systems engineering can be utilized to improve customer satisfaction and profit ability. Specifically, this work will focus on a design methodology for the largest of systems, not necessarily in terms of physical size, but in terms of complexity and interconnectivity.

  16. Epilogue: Systems Approaches and Systems Practice

    Science.gov (United States)

    Reynolds, Martin; Holwell, Sue

    Each of the five systems approaches discussed in this volume: system dynamics (SD), the viable systems model (VSM), strategic options development and analysis (SODA), soft systems methodology (SSM) and critical systems heuristics (CSH) has a pedigree. Not in the sense of the sometimes absurd spectacle of animals paraded at dog shows. Rather, their pedigree derives from their systems foundations, their capacity to evolve and their flexibility in use. None of the five approaches has developed out of use in restricted and controlled contexts of either low or high levels of complicatedness. Neither has any one of them evolved as a consequence of being applied only to situations with either presumed stakeholder agreement on purpose, or courteous disagreement amongst stakeholders, or stakeholder coercion. The compilation is not a celebration of abstract ‘methodologies', but of theoretically robust approaches that have a genuine pedigree in practice.

  17. Influence of ligand coordination of cobalt ions on structural properties of ZnO-ZnF{sub 2}-B{sub 2}O{sub 3} glass system by means of spectroscopic studies

    Energy Technology Data Exchange (ETDEWEB)

    Naresh, P.; Naga Raju, G. [Department of Physics, Acharya Nagarjuna University-Nuzvid Campus, Nuzvid 521201, A.P. (India); Srinivasa Rao, Ch. [Department of Physics, Andhra Loyola College, Vijayawada 520008, A.P. (India); Prasad, S.V.G.V.A. [Department of Physics, Andhra Jateeya Kalasala, Machilipatnam 520001, A.P. (India); Ravi Kumar, V. [Department of Physics, Acharya Nagarjuna University-Nuzvid Campus, Nuzvid 521201, A.P. (India); Veeraiah, N., E-mail: nvr8@rediffmail.com [Department of Physics, Acharya Nagarjuna University-Nuzvid Campus, Nuzvid 521201, A.P. (India)

    2012-02-15

    The glasses of the composition 10ZnO-30ZnF{sub 2}-60B{sub 2}O{sub 3} doped with different concentrations of CoO were prepared. Differential scanning calorimetric (DSC) studies, optical absorption, photoluminescence and infrared spectra of these glasses have been carried out. DSC studies have indicated that the resistance of the glass against devitrification increases with the increase in the concentration of CoO. Optical absorption spectra have exhibited one octahedral band due to {sup 4}T{sub 1g}(F){yields}{sup 2}T{sub 1g}(H) and two tetrahedral bands due to {sup 4}A{sub 2}({sup 4}F){yields}{sup 4}T{sub 1}({sup 4}P) {sup 4}A{sub 2}({sup 4}F){yields}{sup 4}T{sub 1}({sup 4}F) transitions of Co{sup 2+} ions at about 525, 570 and 1400 nm, respectively. As the concentration of CoO is increased the tetrahedral bands are observed to grow at the expense of octahedral band. The luminescence spectra have exhibited two emission bands in the spectral regions of 600-700 nm and 800-900 nm due to {sup 4}T{sub 1}({sup 4}P){yields}{sup 4}A{sub 2}({sup 4}F) and {sup 4}T{sub 1}({sup 4}P){yields}{sup 4}T{sub 2}({sup 4}F) tetrahedral transitions of Co{sup 2+} ions, respectively. With the increasing content of cobalt ions in the glass matrix, the half width and intensity of these bands are observed to increase. The analysis of the results of these two spectra coupled with IR spectra has indicated that as the concentration of CoO is increased in the glass matrix, the tetrahedral occupancy of cobalt ions dominates over the octahedral occupancy and increase the rigidity of the glass network.

  18. Systems analysis of a security alarm system

    International Nuclear Information System (INIS)

    Schiff, A.

    1975-01-01

    When the Lawrence Livermore Laboratory found that its security alarm system was causing more false alarms and maintenance costs than LLL felt was tolerable, a systems analysis was undertaken to determine what should be done about the situation. This report contains an analysis of security alarm systems in general and ends with a review of the existing Security Alarm Control Console (SACC) and recommendations for its improvement, growth and change. (U.S.)

  19. NaPdPS{sub 4} and RbPdPS{sub 4}: systems with infinite straight ((1)/({infinity}))[PdPS{sub 4}]{sup -} chains soluble in polar solvents and the structure of cubic RbPdPS{sub 4}{l_brace}Rb{sub 0.33}P{sub 0.4}S{sub 2.23}O{sub x}{r_brace}

    Energy Technology Data Exchange (ETDEWEB)

    Coste, Servane; Hanko, Jason; Bujoli-Doeuff, Martine; Louarn, Guy; Evain, Michel; Brec, Raymond; Alonso, Bruno; Jobic, S; Kanatzidis, Mercouri G

    2003-11-01

    The synthesis, crystal structures, chemical and spectroscopic properties of NaPdPS{sub 4}, RbPdPS{sub 4}, and RbPdPS{sub 4}{l_brace}Rb{sub 0.33}P{sub 0.4}S{sub 2.23}O{sub x}{r_brace} are described. NaPdPS{sub 4}, RbPdPS{sub 4}, are isostructural and crystallize in the tetragonal system I4/mcm with cell parameters a=7.3074(8) A, c=12.2308(14) A and a=8.2954(3) A, c=12.2284(4) A respectively. RbPdPS{sub 4}{l_brace}Rb{sub 0.33}P{sub 0.4}S{sub 2.23}O{sub x}{r_brace} is cubic, space group Pm-3n and a=12.0042(2) A. All compounds contain the same ((1)/({infinity}))[PdPS{sub 4}]{sup -} chains made of alternating square planar Pd{sup 2+} cations and tetrahedral [PS{sub 4}]{sup 3-} anions. RbPdPS{sub 4}{l_brace}Rb{sub 0.33}P{sub 0.4}S{sub 2.23}O{sub x}{r_brace} contains co-crystallized highly disordered molecular species encapsulated within [Rb{sub 8}] cubic cavities. Spectroscopic solid state {sup 31}P NMR, infrared and Raman data as well as elemental analysis suggest that these species could be S{sub n}{sup 2-} (n=3 or 4) anions and possibly cationic [P{sub 4}S{sub 6}O]{sup 6+} fragments. NaPdPS{sub 4} and RbPdPS{sub 4} exhibit exfoliative dissolution in polar solvents giving rise to solutions that show signs of complex fluid behavior.

  20. Precision digital control systems

    Science.gov (United States)

    Vyskub, V. G.; Rozov, B. S.; Savelev, V. I.

    This book is concerned with the characteristics of digital control systems of great accuracy. A classification of such systems is considered along with aspects of stabilization, programmable control applications, digital tracking systems and servomechanisms, and precision systems for the control of a scanning laser beam. Other topics explored are related to systems of proportional control, linear devices and methods for increasing precision, approaches for further decreasing the response time in the case of high-speed operation, possibilities for the implementation of a logical control law, and methods for the study of precision digital control systems. A description is presented of precision automatic control systems which make use of electronic computers, taking into account the existing possibilities for an employment of computers in automatic control systems, approaches and studies required for including a computer in such control systems, and an analysis of the structure of automatic control systems with computers. Attention is also given to functional blocks in the considered systems.

  1. L-system fractals

    CERN Document Server

    Mishra, Jibitesh

    2007-01-01

    The book covers all the fundamental aspects of generating fractals through L-system. Also it provides insight to various researches in this area for generating fractals through L-system approach & estimating dimensions. Also it discusses various applications of L-system fractals. Key Features: - Fractals generated from L-System including hybrid fractals - Dimension calculation for L-system fractals - Images & codes for L-system fractals - Research directions in the area of L-system fractals - Usage of various freely downloadable tools in this area - Fractals generated from L-System including hybrid fractals- Dimension calculation for L-system fractals- Images & codes for L-system fractals- Research directions in the area of L-system fractals- Usage of various freely downloadable tools in this area

  2. Power system protection 2 systems and methods

    CERN Document Server

    1995-01-01

    The worldwide growth in demand for electricity has forced the pace of developments in electrical power system design to meet consumer needs for reliable, secure and cheap supplies. Power system protection, as a technology essential to high quality supply, is widely recognised as a specialism of growing and often critical importance, in which power system needs and technological progress have combined to result in rapid developments in policy and practice in recent years. In the United Kingdom, the need for appropriate training in power system protection was recognised in the early 1960s with t

  3. Hot Spot Removal System: System description

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    Hazardous wastes contaminated with radionuclides, chemicals, and explosives exist across the Department of Energy complex and need to be remediated due to environmental concerns. Currently, an opportunity is being developed to dramatically reduce remediation costs and to assist in the acceleration of schedules associated with these wastes by deploying a Hot Spot Removal System. Removing the hot spot from the waste site will remove risk driver(s) and enable another, more cost effective process/option/remedial alternative (i.e., capping) to be applied to the remainder of the site. The Hot Spot Removal System consists of a suite of technologies that will be utilized to locate and remove source terms. Components of the system can also be used in a variety of other cleanup activities. This Hot Spot Removal System Description document presents technologies that were considered for possible inclusion in the Hot Spot Removal System, technologies made available to the Hot Spot Removal System, industrial interest in the Hot Spot Removal System`s subsystems, the schedule required for the Hot Spot Removal System, the evaluation of the relevant technologies, and the recommendations for equipment and technologies as stated in the Plan section.

  4. Unmanned Aerial System, New System Manning Prediction

    National Research Council Canada - National Science Library

    Hunn, Bruce P

    2006-01-01

    .... System safety and effectiveness, training, contractor operations and working conditions were evaluated for current UASs, including Hunter, Shadow, Predator, Improved Gnat, and to a lesser degree...

  5. Site systems engineering: Systems engineering management plan

    Energy Technology Data Exchange (ETDEWEB)

    Grygiel, M.L. [Westinghouse Hanford Co., Richland, WA (United States)

    1996-05-03

    The Site Systems Engineering Management Plan (SEMP) is the Westinghouse Hanford Company (WHC) implementation document for the Hanford Site Systems Engineering Policy, (RLPD 430.1) and Systems Engineering Criteria Document and Implementing Directive, (RLID 430.1). These documents define the US Department of Energy (DOE), Richland Operations Office (RL) processes and products to be used at Hanford to implement the systems engineering process at the site level. This SEMP describes the products being provided by the site systems engineering activity in fiscal year (FY) 1996 and the associated schedule. It also includes the procedural approach being taken by the site level systems engineering activity in the development of these products and the intended uses for the products in the integrated planning process in response to the DOE policy and implementing directives. The scope of the systems engineering process is to define a set of activities and products to be used at the site level during FY 1996 or until the successful Project Hanford Management Contractor (PHMC) is onsite as a result of contract award from Request For Proposal DE-RP06-96RL13200. Following installation of the new contractor, a long-term set of systems engineering procedures and products will be defined for management of the Hanford Project. The extent to which each project applies the systems engineering process and the specific tools used are determined by the project`s management.

  6. Hot Spot Removal System: System description

    International Nuclear Information System (INIS)

    1997-09-01

    Hazardous wastes contaminated with radionuclides, chemicals, and explosives exist across the Department of Energy complex and need to be remediated due to environmental concerns. Currently, an opportunity is being developed to dramatically reduce remediation costs and to assist in the acceleration of schedules associated with these wastes by deploying a Hot Spot Removal System. Removing the hot spot from the waste site will remove risk driver(s) and enable another, more cost effective process/option/remedial alternative (i.e., capping) to be applied to the remainder of the site. The Hot Spot Removal System consists of a suite of technologies that will be utilized to locate and remove source terms. Components of the system can also be used in a variety of other cleanup activities. This Hot Spot Removal System Description document presents technologies that were considered for possible inclusion in the Hot Spot Removal System, technologies made available to the Hot Spot Removal System, industrial interest in the Hot Spot Removal System''s subsystems, the schedule required for the Hot Spot Removal System, the evaluation of the relevant technologies, and the recommendations for equipment and technologies as stated in the Plan section

  7. Systems integration of business systems. Business system ni kanshite

    Energy Technology Data Exchange (ETDEWEB)

    Furukawa, H [Nippon Steel Corp., Tokyo (Japan)

    1991-09-26

    System integration (SI) is defined as combining hardwares and softwares as the infrastructures with know-hows for their use comprehensively to respond to high-level needs of users. This paper reports the features of an SI being developed by a company (E Company), its concept on the systematized development methodology, and the conceptual models. With the primary policy placed on creative integration standing on customers positions, the SI concept comprises three parts of models for evaluations as seen from the customers, evaluations as seen from the E Company, and the development object systems to link both parts. The third part is further consisted of several lower hierarchies including a customer controlled system hierarchy (this enables customers to control the system through visualization, for example, and includes three logic models (multiple solution selection, optimal solution under restricted conditions, and numerical solution)). 2 refs., 9 figs.

  8. CDMA systems capacity engineering

    CERN Document Server

    Kim, Kiseon

    2004-01-01

    This new hands-on resource tackles capacity planning and engineering issues that are crucial to optimizing wireless communication systems performance. Going beyond the system physical level and investigating CDMA system capacity at the service level, this volume is the single-source for engineering and analyzing systems capacity and resources.

  9. Smart SDHW systems

    DEFF Research Database (Denmark)

    Andersen, Elsa

    2000-01-01

    The aim of the project is to develop smart solar domestic hot water (SDHW) systems. A smart SDHW is a system in which the domestic water can bee heated both by solar collectors and by an auxiliary energy supply system. The auxiliary energy supply system heats up the hot-water tank from the top an...

  10. Information Systems Security Audit

    OpenAIRE

    Gheorghe Popescu; Veronica Adriana Popescu; Cristina Raluca Popescu

    2007-01-01

    The article covers:Defining an information system; benefits obtained by introducing new information technologies; IT management;Defining prerequisites, analysis, design, implementation of IS; Information security management system; aspects regarding IS security policy; Conceptual model of a security system; Auditing information security systems and network infrastructure security.

  11. Medical imaging systems

    Science.gov (United States)

    Frangioni, John V

    2013-06-25

    A medical imaging system provides simultaneous rendering of visible light and diagnostic or functional images. The system may be portable, and may include adapters for connecting various light sources and cameras in open surgical environments or laparascopic or endoscopic environments. A user interface provides control over the functionality of the integrated imaging system. In one embodiment, the system provides a tool for surgical pathology.

  12. Evolution of ERP systems

    NARCIS (Netherlands)

    Wortmann, J.C.; Bititci, U.S.; Carrie, A.S.

    1998-01-01

    This paper describes the development of ERP systems over time. It explores both the functionality and the technology of ERP-systems. It explains the increased importance of ERP systems in practice. The paper also addresses the difficulties encountered in implementing ERP systems in real life. Modern

  13. Digital processing data communication systems (bus systems). Digitale Prozessdaten-Kommunikations-Systeme (Bus Systeme)

    Energy Technology Data Exchange (ETDEWEB)

    Fleck, K

    1980-01-01

    After an introduction to the technology of digital processing data communication systems there are the following chapters: digital communication of processing data in automation technology, the technology of biserial communication, the implementaiton of a bus system, the data transmission of the TDC-2000 system of Honeywell's and the process bus CS 275 in the automation system TELEPERM M of Siemens AG.

  14. EUCLID ARCHIVE SYSTEM PROTOTYPE

    NARCIS (Netherlands)

    Belikov, Andrey; Williams, Owen; Droge, Bob; Tsyganov, Andrey; Boxhoorn, Danny; McFarland, John; Verdoes Kleijn, Gijs; Valentijn, E; Altieri, Bruno; Dabin, Christophe; Pasian, F.; Osuna, Pedro; Soille, P.; Marchetti, P.G.

    2014-01-01

    The Euclid Archive System prototype is a functional information system which is used to address the numerous challenges in the development of fully functional data processing system for Euclid. The prototype must support the highly distributed nature of the Euclid Science Ground System, with Science

  15. Product Service Systems

    DEFF Research Database (Denmark)

    Departing from Product Development models based on physical artefacts. Moving towards integrated Product Development and System Operations models suited Product/Service-systems......Departing from Product Development models based on physical artefacts. Moving towards integrated Product Development and System Operations models suited Product/Service-systems...

  16. Biogas plant control system

    International Nuclear Information System (INIS)

    Balasevicius, L.; Dervinis, G.; Macerauskas, V.

    2002-01-01

    This paper presents intelligent control system for the pig farm biogas production process. The system uses a fuzzy logic models based on knowledge of experts and operators. Four fuzzy models are introduced. The adequacy of fuzzy models is verified using real data and MATLAB simulation. Proposed expert system is implemented into traditional SCADA system for biogas process prediction and failure analyzing. (authors)

  17. System Performance and Testing

    NARCIS (Netherlands)

    Frei, U.; Oversloot, H.

    2004-01-01

    This chapter compares and contrasts the system performance of two widely used solar thermal systems using testing and simulation programs. Solar thermal systems are used in many countries for heating domestically used water. In addition to the simple thermosiphon systems, better designed pumped

  18. Hybrid intelligent engineering systems

    CERN Document Server

    Jain, L C; Adelaide, Australia University of

    1997-01-01

    This book on hybrid intelligent engineering systems is unique, in the sense that it presents the integration of expert systems, neural networks, fuzzy systems, genetic algorithms, and chaos engineering. It shows that these new techniques enhance the capabilities of one another. A number of hybrid systems for solving engineering problems are presented.

  19. ERP–systems

    OpenAIRE

    Shustova I.

    2016-01-01

    In this work, we analyzed the existing ERP–systems of foreign and domestic manufacturers. Popular ERP–systems in the Republic of Belarus were considered. The leading ERP-systems in the domestic market and their features were described in detail. Finally, we described the steps that must be taken to select the most suitable ERP-system for a particular company.

  20. Business advertisements management system

    OpenAIRE

    Rekel, Ernest

    2017-01-01

    Business Advertisements Management System The main goal of the project was to create a business advertisements management system, where users could easily create and find business advertisements. To accomplish this goal exist- ing systems were analyzed as well as their limitations. The end result is a working system which is able to store and proccess huge amount of data.

  1. Functional System Dynamics

    OpenAIRE

    Ligterink, N.E.

    2007-01-01

    Functional system dynamics is the analysis, modelling, and simulation of continuous systems usually described by partial differential equations. From the infinite degrees of freedom of such systems only a finite number of relevant variables have to be chosen for a practical model description. The proper input and output of the system are an important part of the relevant variables.

  2. Type Systems for Bigraphs

    DEFF Research Database (Denmark)

    Elsborg, Ebbe; Hildebrandt, Thomas; Sangiorgi, Davide

    of controls and a set of reaction rules, collectively a bigraphical reactive system (BRS). Possible advantages of developing bigraphical type systems include: a deeper understanding of a type system itself and its properties; transfer of the type systems to the concrete family of calculi that the BRS models...

  3. Computer Operating System Maintenance.

    Science.gov (United States)

    1982-06-01

    FACILITY The Computer Management Information Facility ( CMIF ) system was developed by Rapp Systems to fulfill the need at the CRF to record and report on...computer center resource usage and utilization. The foundation of the CMIF system is a System 2000 data base (CRFMGMT) which stores and permits access

  4. Balancing for nonlinear systems

    NARCIS (Netherlands)

    Scherpen, J.M.A.

    1993-01-01

    We present a method of balancing for nonlinear systems which is an extension of balancing for linear systems in the sense that it is based on the input and output energy of a system. It is a local result, but gives 'broader' results than we obtain by just linearizing the system. Furthermore, the

  5. EPICS system: system structure and user interface

    International Nuclear Information System (INIS)

    West, R.E.; Bartlett, J.F.; Bobbitt, J.S.; Lahey, T.E.; Kramper, B.J.; MacKinnon, B.A.

    1984-02-01

    This paper present the user's view of and the general organization of the EPICS control system at Fermilab. Various subsystems of the EPICS control system are discussed. These include the user command language, software protection, the device database, remote computer interfaces, and several application utilities. This paper is related to two other papers on EPICS: an overview paper and a detailed implementation paper

  6. Probabilistic fuzzy systems as additive fuzzy systems

    NARCIS (Netherlands)

    Almeida, R.J.; Verbeek, N.; Kaymak, U.; Costa Sousa, da J.M.; Laurent, A.; Strauss, O.; Bouchon-Meunier, B.; Yager, R.

    2014-01-01

    Probabilistic fuzzy systems combine a linguistic description of the system behaviour with statistical properties of data. It was originally derived based on Zadeh’s concept of probability of a fuzzy event. Two possible and equivalent additive reasoning schemes were proposed, that lead to the

  7. System of Systems Analytic Workbench - 2017

    Science.gov (United States)

    2017-08-31

    Genetic Algorithm and Particle Swarm Optimization with Type-2 Fuzzy Sets for Generating Systems of Systems Architectures. Procedia Computer Science...The application effort involves modeling an existing messaging network to perform real-time situational awareness. The Analytical Workbench’s

  8. On generalized Volterra systems

    Science.gov (United States)

    Charalambides, S. A.; Damianou, P. A.; Evripidou, C. A.

    2015-01-01

    We construct a large family of evidently integrable Hamiltonian systems which are generalizations of the KM system. The algorithm uses the root system of a complex simple Lie algebra. The Hamiltonian vector field is homogeneous cubic but in a number of cases a simple change of variables transforms such a system to a quadratic Lotka-Volterra system. We present in detail all such systems in the cases of A3, A4 and we also give some examples from higher dimensions. We classify all possible Lotka-Volterra systems that arise via this algorithm in the An case.

  9. Transdisciplinarity Needs Systemism

    Directory of Open Access Journals (Sweden)

    Wolfgang Hofkirchner

    2017-02-01

    Full Text Available The main message of this paper is that systemism is best suited for transdisciplinary studies. A description of disciplinary sciences, transdisciplinary sciences and systems sciences is given, along with their different definitions of aims, scope and tools. The rationale for transdisciplinarity is global challenges, which are complex. The rationale for systemism is the concretization of understanding complexity. Drawing upon Ludwig von Bertalanffy’s intention of a General System Theory, three items deserve attention—the world-view of a synergistic systems technology, the world picture of an emergentist systems theory, and the way of thinking of an integrationist systems method.

  10. Measuring Systemic Risk

    DEFF Research Database (Denmark)

    Acharya, Viral V.; Heje Pedersen, Lasse; Philippon, Thomas

    2017-01-01

    We present an economic model of systemic risk in which undercapitalization of the financial sector as a whole is assumed to harm the real economy, leading to a systemic risk externality. Each financial institution’s contribution to systemic risk can be measured as its systemic expected shortfall...... of components of SES to predict emerging systemic risk during the financial crisis of 2007–2009....

  11. Multiprocessor data acquisition system

    International Nuclear Information System (INIS)

    Haumann, J.R.; Crawford, R.K.

    1987-01-01

    A multiprocessor data acquisition system has been built to replace the single processor systems at the Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory. The multiprocessor system was needed to accommodate the higher data rates at IPNS brought about by improvements in the source and changes in instrument configurations. This paper describes the hardware configuration of the system and the method of task sharing and compares results to the single processor system

  12. Genetics, systems, and alcohol.

    Science.gov (United States)

    McClearn, G E

    1993-03-01

    Under a variety of rubrics (e.g., complexity, self-constructing systems, dissipative structures), interest has recently burgeoned in applying principles of complex systems to a wide variety of scientific issues. A major concern is with emergent properties of systems not derivable from the properties of components of the systems. In this paper, some elementary aspects of "systems" considerations are applied to phenomena of alcohol pharmacogenetics. It is likely that whole new families of informative phenotypes can be generated by this approach.

  13. Intrusion detection system elements

    International Nuclear Information System (INIS)

    Eaton, M.J.; Mangan, D.L.

    1980-09-01

    This report highlights elements required for an intrusion detection system and discusses problems which can be encountered in attempting to make the elements effective. Topics discussed include: sensors, both for exterior detection and interior detection; alarm assessment systems, with the discussion focused on video assessment; and alarm reporting systems, including alarm communication systems and dislay/console considerations. Guidance on careful planning and design of a new or to-be-improved system is presented

  14. Satellite services system overview

    Science.gov (United States)

    Rysavy, G.

    1982-01-01

    The benefits of a satellite services system and the basic needs of the Space Transportation System to have improved satellite service capability are identified. Specific required servicing equipment are discussed in terms of their technology development status and their operative functions. Concepts include maneuverable television systems, extravehicular maneuvering unit, orbiter exterior lighting, satellite holding and positioning aid, fluid transfer equipment, end effectors for the remote manipulator system, teleoperator maneuvering system, and hand and power tools.

  15. HYBRID VEHICLE CONTROL SYSTEM

    Directory of Open Access Journals (Sweden)

    V. Dvadnenko

    2016-06-01

    Full Text Available The hybrid vehicle control system includes a start–stop system for an internal combustion engine. The system works in a hybrid mode and normal vehicle operation. To simplify the start–stop system, there were user new possibilities of a hybrid car, which appeared after the conversion. Results of the circuit design of the proposed system of basic blocks are analyzed.

  16. The control system

    International Nuclear Information System (INIS)

    1988-01-01

    The present control system has matured both in terms of age and capacity. Thus a new system based on a local area network (LAN) is being developed. A pilot project has been started but, owing to difficulties encountered with the present operating system used with the microprocessors, it has become necessary to reconsider the choice of operating system. A recently-released multi-tasking operating system that runs on the existing hardware has been chosen. 1 fig

  17. SQL injection detection system

    OpenAIRE

    Vargonas, Vytautas

    2017-01-01

    SQL injection detection system Programmers do not always ensure security of developed systems. That is why it is important to look for solutions outside being reliant on developers. In this work SQL injection detection system is proposed. The system analyzes HTTP request parameters and detects intrusions. It is based on unsupervised machine learning. Trained by regular request data system detects outlier user parameters. Since training is not reliant on previous knowledge of SQL injections, t...

  18. Evolvable synthetic neural system

    Science.gov (United States)

    Curtis, Steven A. (Inventor)

    2009-01-01

    An evolvable synthetic neural system includes an evolvable neural interface operably coupled to at least one neural basis function. Each neural basis function includes an evolvable neural interface operably coupled to a heuristic neural system to perform high-level functions and an autonomic neural system to perform low-level functions. In some embodiments, the evolvable synthetic neural system is operably coupled to one or more evolvable synthetic neural systems in a hierarchy.

  19. Telemetry System Data Latency

    Science.gov (United States)

    2017-07-13

    latencies will be measured. DATS Network TM Antenna TM ReceiverMCS System IOPlex IOPlexIADS CDS IADS Client TM Transmitter Sensors Signal Conditioning...TIME Figure 1-2 Mission Control System (MCS) / Interactive Analysis and Display System (IADS) Overview IADS CDSIADS Client TELEMETRY SYSTEM DATA...Sim GPS Signal Combiner MCS system Oscilloscope IADS Client IADS CDS Figure 13-1 IADS Data Flow 13.2. Test Results The results of the data test at

  20. Systems Theory and Systems Approach to Leadership

    Directory of Open Access Journals (Sweden)

    Dr.Sc. Berim Ramosaj

    2014-06-01

    Full Text Available Systems theory is product of the efforts of many researchers to create an intermediate field of coexistence of all sciences. If not for anything else, because of the magnitude that the use of systemic thinking and systemic approach has taken, it has become undisputed among the theories. Systems theory not only provides a glossary of terms with which researchers from different fields can be understood, but provides a framework for the presentation and interpretation of phenomena and realities. This paper addresses a systematic approach to leadership, as an attempt to dredge leadership and systems theory literature to find the meeting point. Systems approach is not an approach to leadership in terms of a manner of leader’s work, but it’s the leader's determination to factorize in his leadership the external environment and relationships with and among elements. Leader without followers is unable to exercise his leadership and to ensure their conviction he should provide a system, a structure, a purpose, despite the alternative chaos. Systems approach clarifies the thought on the complexity and dynamism of the environment and provides a framework for building ideas. If the general system theory is the skeleton of science (Boulding: 1956, this article aims to replenish it with leadership muscles by prominent authors who have written on systems theory and leadership, as well as through original ideas. In this work analytical methods were used (by analyzing approaches individually as well as synthetic methods (by assaying individual approaches in context of entirety. The work is a critical review of literature as well as a deductive analysis mingled with models proposed by authors through inductive analysis. Meta-analysis has been used to dissect the interaction and interdependence between leadership approaches.

  1. A distribution management system

    Energy Technology Data Exchange (ETDEWEB)

    Verho, P.; Jaerventausta, P.; Kaerenlampi, M.; Paulasaari, H. [Tampere Univ. of Technology (Finland); Partanen, J. [Lappeenranta Univ. of Technology (Finland)

    1996-12-31

    The development of new distribution automation applications is considerably wide nowadays. One of the most interesting areas is the development of a distribution management system (DMS) as an expansion of the traditional SCADA system. At the power transmission level such a system is called an energy management system (EMS). The idea of these expansions is to provide supporting tools for control center operators in system analysis and operation planning. The needed data for new applications is mainly available in some existing systems. Thus the computer systems of utilities must be integrated. The main data source for the new applications in the control center are the AM/FM/GIS (i.e. the network database system), the SCADA, and the customer information system (CIS). The new functions can be embedded in some existing computer system. This means a strong dependency on the vendor of the existing system. An alternative strategy is to develop an independent system which is integrated with other computer systems using well-defined interfaces. The latter approach makes it possible to use the new applications in various computer environments, having only a weak dependency on the vendors of the other systems. In the research project this alternative is preferred and used in developing an independent distribution management system

  2. A distribution management system

    Energy Technology Data Exchange (ETDEWEB)

    Verho, P; Jaerventausta, P; Kaerenlampi, M; Paulasaari, H [Tampere Univ. of Technology (Finland); Partanen, J [Lappeenranta Univ. of Technology (Finland)

    1997-12-31

    The development of new distribution automation applications is considerably wide nowadays. One of the most interesting areas is the development of a distribution management system (DMS) as an expansion of the traditional SCADA system. At the power transmission level such a system is called an energy management system (EMS). The idea of these expansions is to provide supporting tools for control center operators in system analysis and operation planning. The needed data for new applications is mainly available in some existing systems. Thus the computer systems of utilities must be integrated. The main data source for the new applications in the control center are the AM/FM/GIS (i.e. the network database system), the SCADA, and the customer information system (CIS). The new functions can be embedded in some existing computer system. This means a strong dependency on the vendor of the existing system. An alternative strategy is to develop an independent system which is integrated with other computer systems using well-defined interfaces. The latter approach makes it possible to use the new applications in various computer environments, having only a weak dependency on the vendors of the other systems. In the research project this alternative is preferred and used in developing an independent distribution management system

  3. Modeling Power Systems as Complex Adaptive Systems

    Energy Technology Data Exchange (ETDEWEB)

    Chassin, David P.; Malard, Joel M.; Posse, Christian; Gangopadhyaya, Asim; Lu, Ning; Katipamula, Srinivas; Mallow, J V.

    2004-12-30

    Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today's most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This report explores the state-of-the-art physical analogs for understanding the behavior of some econophysical systems and deriving stable and robust control strategies for using them. We review and discuss applications of some analytic methods based on a thermodynamic metaphor, according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood. We apply these methods to the question of how power markets can be expected to behave under a variety of conditions.

  4. Rover waste assay system

    Energy Technology Data Exchange (ETDEWEB)

    Akers, D.W.; Stoots, C.M.; Kraft, N.C.; Marts, D.J. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1997-11-01

    The Rover Waste Assay System (RWAS) is a nondestructive assay system designed for the rapid assay of highly-enriched {sup 235}U contaminated piping, tank sections, and debris from the Rover nuclear rocket fuel processing facility at the Idaho Chemical Processing Plant. A scanning system translates a NaI(Tl) detector/collimator system over the structural components where both relative and calibrated measurements for {sup 137}Cs are made. Uranium-235 concentrations are in operation and is sufficiently automated that most functions are performed by the computer system. These functions include system calibration, problem identification, collimator control, data analysis, and reporting. Calibration of the system was done through a combination of measurements on calibration standards and benchmarked modeling. A description of the system is presented along with the methods and uncertainties associated with the calibration and analysis of the system for components from the Rover facility. 4 refs., 2 figs., 4 tabs.

  5. Rover waste assay system

    International Nuclear Information System (INIS)

    Akers, D.W.; Stoots, C.M.; Kraft, N.C.; Marts, D.J.

    1997-01-01

    The Rover Waste Assay System (RWAS) is a nondestructive assay system designed for the rapid assay of highly-enriched 235 U contaminated piping, tank sections, and debris from the Rover nuclear rocket fuel processing facility at the Idaho Chemical Processing Plant. A scanning system translates a NaI(Tl) detector/collimator system over the structural components where both relative and calibrated measurements for 137 Cs are made. Uranium-235 concentrations are in operation and is sufficiently automated that most functions are performed by the computer system. These functions include system calibration, problem identification, collimator control, data analysis, and reporting. Calibration of the system was done through a combination of measurements on calibration standards and benchmarked modeling. A description of the system is presented along with the methods and uncertainties associated with the calibration and analysis of the system for components from the Rover facility. 4 refs., 2 figs., 4 tabs

  6. Micro Information Systems

    DEFF Research Database (Denmark)

    Ulslev Pedersen, Rasmus; Kühn Pedersen, Mogens

    2014-01-01

    such as medical and manufacturing. These new sensor applications have implications for information systems (IS) and, the authors visualize this new class of information systems as fractals growing from an established class of systems; namely that of information systems (IS). The identified applications...... and implications are used as an empirical basis for creating a model for these small new information systems. Such sensor systems are called embedded systems in the technical sciences, and the authors want to couple it with general IS. They call the merger of these two important research areas (IS and embedded...... systems) for micro information systems (micro-IS). It is intended as a new research field within IS research. An initial framework model is established, which seeks to capture both the possibilities and constraints of this new paradigm, while looking simultaneously at the fundamental IS and ICT aspects...

  7. ITER cooling systems

    International Nuclear Information System (INIS)

    Natalizio, A.; Hollies, R.E.; Sochaski, R.O.; Stubley, P.H.

    1992-06-01

    The ITER reference system uses low-temperature water for heat removal and high-temperature helium for bake-out. As these systems share common equipment, bake-out cannot be performed until the cooling system is drained and dried, and the reactor cannot be started until the helium has been purged from the cooling system. This study examines the feasibility of using a single high-temperature fluid to perform both heat removal and bake-out. The high temperature required for bake-out would also be in the range for power production. The study examines cost, operational benefits, and impact on reactor safety of two options: a high-pressure water system, and a low-pressure organic system. It was concluded that the cost savings and operational benefits are significant; there are no significant adverse safety impacts from operating either the water system or the organic system; and the capital costs of both systems are comparable

  8. System performance optimization

    International Nuclear Information System (INIS)

    Bednarz, R.J.

    1978-01-01

    The System Performance Optimization has become an important and difficult field for large scientific computer centres. Important because the centres must satisfy increasing user demands at the lowest possible cost. Difficult because the System Performance Optimization requires a deep understanding of hardware, software and workload. The optimization is a dynamic process depending on the changes in hardware configuration, current level of the operating system and user generated workload. With the increasing complication of the computer system and software, the field for the optimization manoeuvres broadens. The hardware of two manufacturers IBM and CDC is discussed. Four IBM and two CDC operating systems are described. The description concentrates on the organization of the operating systems, the job scheduling and I/O handling. The performance definitions, workload specification and tools for the system stimulation are given. The measurement tools for the System Performance Optimization are described. The results of the measurement and various methods used for the operating system tuning are discussed. (Auth.)

  9. NASA systems engineering handbook

    Science.gov (United States)

    Shishko, Robert; Aster, Robert; Chamberlain, Robert G.; McDuffee, Patrick; Pieniazek, Les; Rowell, Tom; Bain, Beth; Cox, Renee I.; Mooz, Harold; Polaski, Lou

    1995-06-01

    This handbook brings the fundamental concepts and techniques of systems engineering to NASA personnel in a way that recognizes the nature of NASA systems and environment. It is intended to accompany formal NASA training courses on systems engineering and project management when appropriate, and is designed to be a top-level overview. The concepts were drawn from NASA field center handbooks, NMI's/NHB's, the work of the NASA-wide Systems Engineering Working Group and the Systems Engineering Process Improvement Task team, several non-NASA textbooks and guides, and material from independent systems engineering courses taught to NASA personnel. Five core chapters cover systems engineering fundamentals, the NASA Project Cycle, management issues in systems engineering, systems analysis and modeling, and specialty engineering integration. It is not intended as a directive.

  10. Expert systems and computer based industrial systems

    International Nuclear Information System (INIS)

    Dunand, R.

    1989-01-01

    Framentec is the artificial intelligence subsidiary of FRAMATOME. It is involved in expert-system activities of Shells, developments, methodology and software for maintenance (Maintex) and consulting and methodology. Specific applications in the nuclear field are presented. The first is an expert system to assist in the piping support design prototype, the second is an expert system that assists an ultrasonic testing operator in determining the nature of a welding defect and the third is a welding machine diagnosis advisor. Maintex is a software tool to provide assistance in the repair of complex industrial equipment. (author)

  11. Visualization System for Monitoring Data Management Systems

    Directory of Open Access Journals (Sweden)

    Emanuel Pinho

    2016-11-01

    Full Text Available Usually, a Big Data system has a monitoring system for performance evaluation and error prevention. There are some disadvantages in the way that these tools display the information and its targeted approach to physical components. The main goal is to study visual and interactive mechanisms that allow the representation of monitoring data in grid computing environments, providing the end-user information, which can contribute objectively to the system analysis. This paper is an extension of the paper presented at (Pinho and Carvalho 2016 and has the purpose to present the state of the art, carries out the proposed solution and present the achieved goals.

  12. System architecture for microprocessor based protection system

    International Nuclear Information System (INIS)

    Gallagher, J.M. Jr.; Lilly, G.M.

    1976-01-01

    This paper discusses the architectural design features to be employed by Westinghouse in the application of distributed digital processing techniques to the protection system. While the title of the paper makes specific reference to microprocessors, this is only one (and the newest) of the building blocks which constitutes a distributed digital processing system. The actual system structure (as realized through utilization of the various building blocks) is established through considerations of reliability, licensability, and cost. It is the intent of the paper to address these considerations licenstions as they relate to the architectural design features. (orig.) [de

  13. Embedded systems handbook networked embedded systems

    CERN Document Server

    Zurawski, Richard

    2009-01-01

    Considered a standard industry resource, the Embedded Systems Handbook provided researchers and technicians with the authoritative information needed to launch a wealth of diverse applications, including those in automotive electronics, industrial automated systems, and building automation and control. Now a new resource is required to report on current developments and provide a technical reference for those looking to move the field forward yet again. Divided into two volumes to accommodate this growth, the Embedded Systems Handbook, Second Edition presents a comprehensive view on this area

  14. Modern system architectures in embedded systems

    International Nuclear Information System (INIS)

    Korhonen, T.

    2012-01-01

    Several new technologies are making their way also in embedded systems. In addition to the FPGA technology which has become commonplace, multi-core CPUs and I/O virtualization (the implementation of the tasks of a software hyper-visor in hardware to improve the efficiency) are being introduced to the embedded systems. In this paper we review the trends and discuss how to take advantage of these features in control systems. Some potential application examples like parallelization, data streaming, high-speed data acquisition and virtualization are discussed

  15. Nonlinearity of colloid systems oxyhydrate systems

    CERN Document Server

    Sucharev, Yuri I

    2008-01-01

    The present monograph is the first systematic study of the non-linear characteristic of gel oxy-hydrate systems involving d- and f- elements. These are the oxyhydrates of rare-earth elements and oxides - hydroxides of d- elements (zirconium, niobium, titanium, etc.) The non-linearity of these gel systems introduces fundamental peculiarities into their structure and, consequently, their properties. The polymer-conformational diversity of energetically congenial gel fragments, which continu-ously transform under the effect of, for instance, system dissipation heat, is central to the au-thor's hy

  16. Information system development activities and inquiring systems

    DEFF Research Database (Denmark)

    Carugati, Andrea

    2008-01-01

    This article presents a framework that maps information system development (ISD) activities on systems for the creation of knowledge. This work addresses the relevant and persisting problem of improving the chances of ISD success. The article builds upon previous research on knowledge aspects...... based on ISD literature and on Churchman's (1971) inquiring systems. The second part presents the use of the framework in an ISD project. The case is used to show the applicability of the framework and to highlight the advantages of this approach. The main theoretical implication is that the framework...

  17. Automatic remote communication system

    International Nuclear Information System (INIS)

    Yamamoto, Yoichi

    1990-05-01

    The Upgraded RECOVER (Remote Continual Verification) system is a communication system for remote continual verification of security and safeguards status of nuclear material in principal nuclear facilities. The system is composed of a command center and facility sub-systems. A command center is a mini-computer system to process C/S (Containment and Surveillance) status data. Facility sub-systems consists of OSM (On-site Multiplexer), MU (Monitoring Unit) and C/S sensor. The system uses public telephone network for communication between a command center and facility sub-systems, and it encrypts communication data to prevent falsification and wiretapping by unauthorized persons. This system inherits the design principle of RECOVER system that was tested by IAEA before. We upgraded and expanded its capabilities more than those of RECOVER. The development of this system began in 1983, and it finished in 1987. Performance tests of the system were carried out since 1987. It showed a farely good result with some indications which should need further improvements. The Upgraded RECOVER system provides timely information about the status of C/S systems, which could contribute to the reduction of inspection effort and the improvement of cost performance. (author)

  18. Photovoltaic systems engineering

    CERN Document Server

    Messenger, Roger A

    2010-01-01

    BackgroundPopulation and Energy DemandEnergy UnitsCurrent World Energy Use PatternsExponential GrowthHubbert's Gaussian ModelNet Energy, Btu Economics, and the Test for SustainabilityDirect Conversion of Sunlight to Electricity with PhotovoltaicsThe SunThe Solar SpectrumThe Effect of Atmosphere on SunlightSunlight SpecificsCapturing SunlightIntroduction to PV SystemsThe PV CellThe PV ModuleThe PV ArrayEnergy StoragePV System LoadsPV System AvailabilityAssociated System Electronic ComponentsGeneratorsBalance of System (BOS) ComponentsGrid-Connected Utility-Interactive PV SystemsApplicable Codes and StandardsDesign Considerations for Straight Grid-Connected PV SystemsDesign of a System Based on Desired Annual System PerformanceDesign of a System Based on Available Roof SpaceDesign of a Microinverter-Based SystemDesign of a Nominal 21 kW System that Feeds a Three-Phase Distribution PanelDesign of a Nominal 250 kW SystemSystem Performance MonitoringMechanical ConsiderationsImportant Properties of MaterialsEstabli...

  19. T-systems and Y-systems in integrable systems

    International Nuclear Information System (INIS)

    Kuniba, Atsuo; Nakanishi, Tomoki; Suzuki, Junji

    2011-01-01

    T- and Y-systems are ubiquitous structures in classical and quantum integrable systems. They are difference equations having a variety of aspects related to commuting transfer matrices in solvable lattice models, q-characters of Kirillov-Reshetikhin modules of quantum affine algebras, cluster algebras with coefficients, periodicity conjectures of Zamolodchikov and others, dilogarithm identities in conformal field theory, difference analog of L-operators in KP hierarchy, Stokes phenomena in 1D Schroedinger problem, AdS/CFT correspondence, Toda field equations on discrete spacetime, Laplace sequence in discrete geometry, Fermionic character formulas and combinatorial completeness of Bethe ansatz, Q-system and ideal gas with exclusion statistics, analytic and thermodynamic Bethe ansaetze, quantum transfer matrix method and so forth. This review is a collection of short reviews on these topics which can be read more or less independently. (topical review)

  20. T-systems and Y-systems in integrable systems

    Energy Technology Data Exchange (ETDEWEB)

    Kuniba, Atsuo [Institute of Physics, University of Tokyo, Komaba, Tokyo 153-8902 (Japan); Nakanishi, Tomoki [Graduate School of Mathematics, Nagoya University, Nagoya 464-8604 (Japan); Suzuki, Junji, E-mail: atsuo@gokutan.c.u-tokyo.ac.jp [Department of Physics, Faculty of Science, Shizuoka University, Ohya 836 (Japan)

    2011-03-11

    T- and Y-systems are ubiquitous structures in classical and quantum integrable systems. They are difference equations having a variety of aspects related to commuting transfer matrices in solvable lattice models, q-characters of Kirillov-Reshetikhin modules of quantum affine algebras, cluster algebras with coefficients, periodicity conjectures of Zamolodchikov and others, dilogarithm identities in conformal field theory, difference analog of L-operators in KP hierarchy, Stokes phenomena in 1D Schroedinger problem, AdS/CFT correspondence, Toda field equations on discrete spacetime, Laplace sequence in discrete geometry, Fermionic character formulas and combinatorial completeness of Bethe ansatz, Q-system and ideal gas with exclusion statistics, analytic and thermodynamic Bethe ansaetze, quantum transfer matrix method and so forth. This review is a collection of short reviews on these topics which can be read more or less independently. (topical review)

  1. Cooperating systems: Layered MAS

    Science.gov (United States)

    Rochowiak, Daniel

    1990-01-01

    Distributed intelligent systems can be distinguished by the models that they use. The model developed focuses on layered multiagent system conceived of as a bureaucracy in which a distributed data base serves as a central means of communication. The various generic bureaus of such a system is described and a basic vocabulary for such systems is presented. In presenting the bureaus and vocabularies, special attention is given to the sorts of reasonings that are appropriate. A bureaucratic model has a hierarchy of master system and work group that organizes E agents and B agents. The master system provides the administrative services and support facilities for the work groups.

  2. Simulation of Polygeneration Systems

    Directory of Open Access Journals (Sweden)

    Francesco Calise

    2016-11-01

    Full Text Available This Special Issue aims at collecting the recent studies dealing with polygeneration systems, with a special focus on the possible integration of different technologies into a single system, able to convert one or multiple energy sources into energy services (electricity, heat and cooling and other useful products (e.g., desalinized water, hydrogen, glycerin, ammonia, etc.. Renewable sources (solar, wind, hydro, biomass and geothermal, as well as fossil fuels, feeding advanced energy systems such as fuel cells and cogeneration systems, are considered. Special attention is paid to control strategies and to the management of the systems in general. Studies including thermoeconomic analyses and system optimizations are presented.

  3. The BELLE DAQ system

    Science.gov (United States)

    Suzuki, Soh Yamagata; Yamauchi, Masanori; Nakao, Mikihiko; Itoh, Ryosuke; Fujii, Hirofumi

    2000-10-01

    We built a data acquisition system for the BELLE experiment. The system was designed to cope with the average trigger rate up to 500 Hz at the typical event size of 30 kB. This system has five components: (1) the readout sequence controller, (2) the FASTBUS-TDC readout systems using charge-to-time conversion, (3) the barrel shifter event builder, (4) the parallel online computing farm, and (5) the data transfer system to the mass storage. This system has been in operation for physics data taking since June 1999 without serious problems.

  4. The BELLE DAQ system

    International Nuclear Information System (INIS)

    Suzuki, Soh Yamagata; Yamauchi, Masanori; Nakao, Mikihiko; Itoh, Ryosuke; Fujii, Hirofumi

    2000-01-01

    We built a data acquisition system for the BELLE experiment. The system was designed to cope with the average trigger rate up to 500 Hz at the typical event size of 30 kB. This system has five components: (1) the readout sequence controller, (2) the FASTBUS-TDC readout systems using charge-to-time conversion, (3) the barrel shifter event builder, (4) the parallel online computing farm, and (5) the data transfer system to the mass storage. This system has been in operation for physics data taking since June 1999 without serious problems

  5. Reliable computer systems.

    Science.gov (United States)

    Wear, L L; Pinkert, J R

    1993-11-01

    In this article, we looked at some decisions that apply to the design of reliable computer systems. We began with a discussion of several terms such as testability, then described some systems that call for highly reliable hardware and software. The article concluded with a discussion of methods that can be used to achieve higher reliability in computer systems. Reliability and fault tolerance in computers probably will continue to grow in importance. As more and more systems are computerized, people will want assurances about the reliability of these systems, and their ability to work properly even when sub-systems fail.

  6. Adaptive intrusion data system

    International Nuclear Information System (INIS)

    Johnson, C.S.

    1976-01-01

    An Adaptive Intrusion Data System (AIDS) was developed to collect data from intrusion alarm sensors as part of an evaluation system to improve sensor performance. AIDS is a unique digital data compression, storage, and formatting system. It also incorporates capability for video selection and recording for assessment of the sensors monitored by the system. The system is software reprogrammable to numerous configurations that may be utilized for the collection of environmental, bi-level, analog and video data. The output of the system is digital tapes formatted for direct data reduction on a CDC 6400 computer, and video tapes containing timed tagged information that can be correlated with the digital data

  7. Introducing Systems Approaches

    Science.gov (United States)

    Reynolds, Martin; Holwell, Sue

    Systems Approaches to Managing Change brings together five systems approaches to managing complex issues, each having a proven track record of over 25 years. The five approaches are: System Dynamics (SD) developed originally in the late 1950s by Jay Forrester Viable Systems Model (VSM) developed originally in the late 1960s by Stafford Beer Strategic Options Development and Analysis (SODA: with cognitive mapping) developed originally in the 1970s by Colin Eden Soft Systems Methodology (SSM) developed originally in the 1970s by Peter Checkland Critical Systems Heuristics (CSH) developed originally in the late 1970s by Werner Ulrich

  8. EPICS system: an overview

    International Nuclear Information System (INIS)

    Bartlett, J.F.; Bobbitt, J.S.; Kramper, B.J.; Lahey, T.E.; MacKinnon, B.A.; West, R.E.

    1984-02-01

    This paper presents an overview of the EPICS control system at FERMILAB. EPICS is a distributed, multi-user, interactive system for the control and monitoring of particle beamlines at a high-energy experimental physics laboratory. The overview discusses the operating environment of the control system, the requirements which determined the design decisions, the hardware and software configurations, and plans for the future growth and enhancement of the present system. This paper is the first of three related papers on the EPICS system. The other two cover (1) the system structure and user interface and (2) RSX implementation issues

  9. Nonlinear Hamiltonian systems

    DEFF Research Database (Denmark)

    Jørgensen, Michael Finn

    1995-01-01

    It is generally very difficult to solve nonlinear systems, and such systems often possess chaotic solutions. In the rare event that a system is completely solvable, it is said to integrable. Such systems never have chaotic solutions. Using the Inverse Scattering Transform Method (ISTM) two...... particular configurations of the Discrete Self-Trapping (DST) system are shown to be completely solvable. One of these systems includes the Toda lattice in a certain limit. An explicit integration is carried through for this Near-Toda lattice. The Near-Toda lattice is then generalized to include singular...

  10. LCA of Energy Systems

    DEFF Research Database (Denmark)

    Laurent, Alexis; Espinosa Martinez, Nieves; Hauschild, Michael Zwicky

    2018-01-01

    Energy systems are essential in the support of modern societies’ activities, and can span a wide spectrum of electricity and heat generation systems and cooling systems. Along with their central role and large diversity, these systems have been demonstrated to cause serious impacts on human health...... , ecosystems and natural resources. Over the past two decades, energy systems have thus been the focus of more than 1000 LCA studies, with the aim to identify and reduce these impacts. This chapter addresses LCA applications to energy systems for generation of electricity and heat . The chapter gives insight...

  11. Two Tethered Balloon Systems

    Science.gov (United States)

    Youngbluth, Otto; Owens, Thomas L.; Storey, Richard W.

    1990-01-01

    Systems take meteorological measurements for variety of research projects. Report describes work done by NASA Langley Research Center in atmospheric research using tethered balloon systems composed of commercially available equipment. Two separate tethered balloon systems described in report have payloads and configurations tailored to requirements of specific projects. Each system capable of measuring atmospheric parameter or species in situ and then telemetering this data in real time to ground station. Meteorological data and concentration of ozone typically measured. Indicates instrumented tethered balloon systems have distinct advantages over other systems for gathering data on troposphere.

  12. Microelectronic systems 1 checkbook

    CERN Document Server

    Vears, R E

    2013-01-01

    Microelectronic Systems 1 Checkbook provides coverage of the Business and Technician Education Council level 1 unit in Microelectronic Systems. However, it can be regarded as a basic textbook in microelectronic systems for a much wider range of studies. Each topic considered in the text is presented in a way that assumes the reader has little prior knowledge of electronics. The aim of the book is to provide an introduction to the concept of systems, to differentiate analogue and digital systems, and to describe the nature of microprocessor-controlled systems. An introduction to programming is

  13. Quality data systems

    International Nuclear Information System (INIS)

    Bergman, J.E.; Patterson, R.G.

    1976-01-01

    General Electric's Nuclear Fuel Department data system strategy of multifunctional system integration and specific applications of data systems for the Quality Assurance Programme is detailed. Descriptions of two manufacturing control systems and their function in satisfying quality data requirements are included. The timesharing quality data system developed for processing laboratory, traceability and material release data in the Fuel Manufacturing Operation is described. In addition, specific references are made to those areas where significant time reductions have been realized through the utilization of mechanized data-handling systems. (author)

  14. Water Fluoridation Reporting System (Public Water Systems)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Water Fluoridation Reporting System (WFRS) has been developed to provide tools to assist states in managing fluoridation programs. WFRS is designed to track all...

  15. Combat Systems Department Employee Recognition System

    National Research Council Canada - National Science Library

    1996-01-01

    This handbook contains two types of information: guidelines and instructions. The guidelines provide a foundation of purpose, assumptions, principles, expectations and attributes the Employee Recognition System is designed to reflect...

  16. Test System Impact on System Availability

    DEFF Research Database (Denmark)

    Pau, L. F.

    1987-01-01

    The specifications are presented for an imperfect automatic test system (ATS) (test frequency distribution, reliability, false alarm rate, nondetection rate) in order to account for the availability, readiness, mean time between unscheduled repairs (MTBUR), reliability, and maintenance of the sys......The specifications are presented for an imperfect automatic test system (ATS) (test frequency distribution, reliability, false alarm rate, nondetection rate) in order to account for the availability, readiness, mean time between unscheduled repairs (MTBUR), reliability, and maintenance...... of the system subject to monitoring and test. A time-dependent Markov model is presented, and applied in three cases, with examples of numerical results provided for preventive maintenance decisions, design of an automatic test system, buffer testing in computers, and data communications....

  17. An expert system for reward systems design.

    OpenAIRE

    Erturk, Alper

    2000-01-01

    Approved for public release; distribution is unlimited Today's business environment is a highly competitive marketplace. In this competition, organizations distribute numerous rewards to motivate, attract and retain employees, such as pay, fringe benefits and promotions. However, not all managers have the necessary knowledge and expertise to effectively decide and structure reward systems. This thesis presents an expert system to assist managers with designing the most appropriate reward s...

  18. SUBSURFACE EMPLACEMENT TRANSPORTATION SYSTEM

    International Nuclear Information System (INIS)

    Wilson, T.; Novotny, R.

    1999-01-01

    The objective of this analysis is to identify issues and criteria that apply to the design of the Subsurface Emplacement Transportation System (SET). The SET consists of the track used by the waste package handling equipment, the conductors and related equipment used to supply electrical power to that equipment, and the instrumentation and controls used to monitor and operate those track and power supply systems. Major considerations of this analysis include: (1) Operational life of the SET; (2) Geometric constraints on the track layout; (3) Operating loads on the track; (4) Environmentally induced loads on the track; (5) Power supply (electrification) requirements; and (6) Instrumentation and control requirements. This analysis will provide the basis for development of the system description document (SDD) for the SET. This analysis also defines the interfaces that need to be considered in the design of the SET. These interfaces include, but are not limited to, the following: (1) Waste handling building; (2) Monitored Geologic Repository (MGR) surface site layout; (3) Waste Emplacement System (WES); (4) Waste Retrieval System (WRS); (5) Ground Control System (GCS); (6) Ex-Container System (XCS); (7) Subsurface Electrical Distribution System (SED); (8) MGR Operations Monitoring and Control System (OMC); (9) Subsurface Facility System (SFS); (10) Subsurface Fire Protection System (SFR); (11) Performance Confirmation Emplacement Drift Monitoring System (PCM); and (12) Backfill Emplacement System (BES)

  19. Solar power satellite system; Uchu hatsuden system

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, S [Institute of Space and Astronautical Science, Tokyo (Japan)

    1995-09-05

    The solar power satellite system is a system that converts solar energy into electric energy in the space, transmits power to earth through wireless resort such as microwave and supplies energy of new concept. In order to realize this system it is necessary to have new technologies such as space power transmission at low cost, construction of large space buildings and wireless high power transmission. In this paper, the principles, characteristics and the necessary technology of this system were explained. Besides Japan`s SPS2000 Plan (cooperative research by universities, government agencies and private corporations on the model of solar power satellite) the group of Europe, Russia and the United States has also proposed some ideas concerning the solar power satellite system. As far as the microwave power transmission, which is the key technology for solar power satellite system, is concerned, ground demonstration tests at the level of several tens of kW are discussed in Canada and France. 3 refs., 3 figs.

  20. System and method for creating expert systems

    Science.gov (United States)

    Hughes, Peter M. (Inventor); Luczak, Edward C. (Inventor)

    1998-01-01

    A system and method provides for the creation of a highly graphical expert system without the need for programming in code. An expert system is created by initially building a data interface, defining appropriate Mission, User-Defined, Inferred, and externally-generated GenSAA (EGG) data variables whose data values will be updated and input into the expert system. Next, rules of the expert system are created by building appropriate conditions of the rules which must be satisfied and then by building appropriate actions of rules which are to be executed upon corresponding conditions being satisfied. Finally, an appropriate user interface is built which can be highly graphical in nature and which can include appropriate message display and/or modification of display characteristics of a graphical display object, to visually alert a user of the expert system of varying data values, upon conditions of a created rule being satisfied. The data interface building, rule building, and user interface building are done in an efficient manner and can be created without the need for programming in code.

  1. Business system: Sustainable development and anticipatory system

    Directory of Open Access Journals (Sweden)

    Vojko Potočan

    2002-01-01

    Full Text Available The existence and development of humankind depends mainly upon the co-ordinated operation of all areas and levels of human activity. However, in theory and in practice there is no model of operation, which would provide a harmonized and target oriented development. A partial solution is offered by sustainable development, which tries to define and carry out common goals of mankind with a harmonized implementation of human activities at all levels of its living and behaviour. Companies belong to central institutions of modern society which essentially co–create the sustainability of society. The company’s endeavour by simulation to prepare models of their goals concerning their internal and external environment. On the base of systemic treatment, we can define companies as business system, which can survive in a log-run only on the basis of sustainable development. The business system can also be supported by the application of the anticipatory systems. The anticipatory systems can be, in this sense, understood as an entity of the methodological approach, techniques and modes of work. Their characteristics have, a direct impact on the determination of goals, on the orientation of operation, and hence on the achievement of the business system results.

  2. Operating System for Runtime Reconfigurable Multiprocessor Systems

    Directory of Open Access Journals (Sweden)

    Diana Göhringer

    2011-01-01

    Full Text Available Operating systems traditionally handle the task scheduling of one or more application instances on processor-like hardware architectures. RAMPSoC, a novel runtime adaptive multiprocessor System-on-Chip, exploits the dynamic reconfiguration on FPGAs to generate, start and terminate hardware and software tasks. The hardware tasks have to be transferred to the reconfigurable hardware via a configuration access port. The software tasks can be loaded into the local memory of the respective IP core either via the configuration access port or via the on-chip communication infrastructure (e.g. a Network-on-Chip. Recent-series of Xilinx FPGAs, such as Virtex-5, provide two Internal Configuration Access Ports, which cannot be accessed simultaneously. To prevent conflicts, the access to these ports as well as the hardware resource management needs to be controlled, e.g. by a special-purpose operating system running on an embedded processor. For that purpose and to handle the relations between temporally and spatially scheduled operations, the novel approach of an operating system is of high importance. This special purpose operating system, called CAP-OS (Configuration Access Port-Operating System, which will be presented in this paper, supports the clients using the configuration port with the services of priority-based access scheduling, hardware task mapping and resource management.

  3. FFTF gas processing systems

    International Nuclear Information System (INIS)

    Halverson, T.G.

    1977-01-01

    The design and operation of the two radioactive gas processing systems at the Fast Flux Test Facility (FFTF) exemplifies the concept that will be used in the first generation of Liquid Metal Fast Breeder Reactors (LMFBR's). The two systems, the Radioactive Argon Processing System (RAPS) and the Cell Atmosphere Processing System (CAPS), process the argon and nitrogen used in the FFTF for cover gas on liquid metal systems and as inert atmospheres in steel lined cells housing sodium equipment. The RAPS specifically processes the argon cover gas from the reactor coolant system, providing for decontamination and eventual reuse. The CAPS processes radioactive gasses from inerted cells and other liquid metal cover gas systems, providing for decontamination and ultimate discharge to the atmosphere. The cryogenic processing of waste gas by both systems is described

  4. Optical Airborne Tracker System

    Data.gov (United States)

    National Aeronautics and Space Administration — The Optical Airborne Tracker System (OATS) is an airborne dual-axis optical tracking system capable of pointing at any sky location or ground target.  The objectives...

  5. Absorption heat pump system

    Science.gov (United States)

    Grossman, G.

    1982-06-16

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  6. Immune System (For Parents)

    Science.gov (United States)

    ... of the Immune System Print en español El sistema inmunitario The immune system, which is made up ... of Use Notice of Nondiscrimination Visit the Nemours Web site. Note: All information on KidsHealth® is for ...

  7. Designing automatic resupply systems.

    Science.gov (United States)

    Harding, M L

    1999-02-01

    This article outlines the process for designing and implementing autoresupply systems. The planning process includes determination of goals and appropriate participation. Different types of autoresupply mechanisms include kanban, breadman, consignment, systems contracts, and direct shipping from an MRP schedule.

  8. Organizing Systemic Innovation

    NARCIS (Netherlands)

    F.P.H. Jaspers (Ferdinand)

    2009-01-01

    textabstractSystemic innovation refers to product development activities that involve the change of multiple interdependent components. Unlike autonomous innovation, which refers to components that change independently, systemic innovation is for many firms the norm rather than the exception. This

  9. FAA Directives System

    Science.gov (United States)

    1992-08-26

    Consistent with the Federal Aviation Administration's mission to foster a safe, : secure, and efficient aviation system is the need for an effective and efficient : process for communitcating policy and procedures. The FAA Directives System : provide...

  10. Geographical information systems

    DEFF Research Database (Denmark)

    Möller, Bernd

    2004-01-01

    The chapter gives an introduction to Geographical Information Systems (GIS) with particular focus on their application within environmental management.......The chapter gives an introduction to Geographical Information Systems (GIS) with particular focus on their application within environmental management....

  11. Septic Systems Case Studies

    Science.gov (United States)

    A collection of septic systems case studies to help community planners, elected officials, health department staff, state officials, and interested citizens explore alternatives for managing their decentralized wastewater treatment systems.

  12. Inductive Monitoring System (IMS)

    Data.gov (United States)

    National Aeronautics and Space Administration — IMS: Inductive Monitoring System The Inductive Monitoring System (IMS) is a tool that uses a data mining technique called clustering to extract models of normal...

  13. Visitor Registration System

    Data.gov (United States)

    US Agency for International Development — Visitor Registration System (VRS) streamlines visitor check-in and check-out process for expediting visitors into USAID. The system captures visitor information...

  14. Information retrieval system

    Science.gov (United States)

    Berg, R. F.; Holcomb, J. E.; Kelroy, E. A.; Levine, D. A.; Mee, C., III

    1970-01-01

    Generalized information storage and retrieval system capable of generating and maintaining a file, gathering statistics, sorting output, and generating final reports for output is reviewed. File generation and file maintenance programs written for the system are general purpose routines.

  15. Semiotic labelled deductive systems

    Energy Technology Data Exchange (ETDEWEB)

    Nossum, R.T. [Imperial College of Science, Technology and Medicine, London (United Kingdom)

    1996-12-31

    We review the class of Semiotic Models put forward by Pospelov, as well as the Labelled Deductive Systems developed by Gabbay, and construct an embedding of Semiotic Models into Labelled Deductive Systems.

  16. Integrated Reporting Information System -

    Data.gov (United States)

    Department of Transportation — The Integrated Reporting Information System (IRIS) is a flexible and scalable web-based system that supports post operational analysis and evaluation of the National...

  17. HVAC systems and equipment

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, S.T. (Linford Air and Refrigeration Company, Oakland, CA (US))

    1990-02-01

    The author discusses the section of the ASHRAE Standard 90.1-1989 which addresses HVAC systems and equipment. New features of HVAC systems mandatory general requirements are described. New prescriptive requirements are detailed.

  18. Integrated security system definition

    International Nuclear Information System (INIS)

    Campbell, G.K.; Hall, J.R. II

    1985-01-01

    The objectives of an integrated security system are to detect intruders and unauthorized activities with a high degree of reliability and the to deter and delay them until effective response/engagement can be accomplished. Definition of an effective integrated security system requires proper application of a system engineering methodology. This paper summarizes a methodology and describes its application to the problem of integrated security system definition. This process includes requirements identification and analysis, allocation of identified system requirements to the subsystem level and provides a basis for identification of synergistic subsystem elements and for synthesis into an integrated system. The paper discusses how this is accomplished, emphasizing at each step how system integration and subsystem synergism is considered. The paper concludes with the product of the process: implementation of an integrated security system

  19. Electrical railway transportation systems

    CERN Document Server

    Brenna, Morris; Zaninelli, Dario

    2018-01-01

    Allows the reader to deepen their understanding of various technologies for both fixed power supply installations of railway systems and for railway rolling stock. This book explores the electric railway systems that play a crucial role in the mitigation of congestion and pollution caused by road traffic. It is divided into two parts: the first covering fixed power supply systems, and the second concerning the systems for railway rolling stock. In particular, after a historical introduction to the framework of technological solutions in current use, the authors investigate electrification systems for the power supply of rail vehicles, trams, and subways. Electrical Railway Transportation Systems explores the direct current systems used throughout the world for urban and suburban transport, which are also used in various countries for regional transport. It provides a study of alternating current systems, whether for power supply frequency or for special railway frequency, that are used around the world for ...

  20. Avian respiratory system disorders

    Science.gov (United States)

    Olsen, Glenn H.

    1989-01-01

    Diagnosing and treating respiratory diseases in avian species requires a basic knowledge about the anatomy and physiology of this system in birds. Differences between mammalian and avian respiratory system function, diagnosis, and treatment are highlighted.