WorldWideScience

Sample records for hermitian transfinite element

  1. Automatic terrain modeling using transfinite element analysis

    KAUST Repository

    Collier, Nathan

    2010-05-31

    An automatic procedure for modeling terrain is developed based on L2 projection-based interpolation of discrete terrain data onto transfinite function spaces. The function space is refined automatically by the use of image processing techniques to detect regions of high error and the flexibility of the transfinite interpolation to add degrees of freedom to these areas. Examples are shown of a section of the Palo Duro Canyon in northern Texas.

  2. Hermitian Mindlin Plate Wavelet Finite Element Method for Load Identification

    OpenAIRE

    Xiaofeng Xue; Xuefeng Chen; Xingwu Zhang; Baijie Qiao; Jia Geng

    2016-01-01

    A new Hermitian Mindlin plate wavelet element is proposed. The two-dimensional Hermitian cubic spline interpolation wavelet is substituted into finite element functions to construct frequency response function (FRF). It uses a system’s FRF and response spectrums to calculate load spectrums and then derives loads in the time domain via the inverse fast Fourier transform. By simulating different excitation cases, Hermitian cubic spline wavelets on the interval (HCSWI) finite elements are used t...

  3. Transfinite element methodology for nonlinear/linear transient thermal modelling/analysis - Progress and recent advances

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1988-01-01

    The 'transfinite element method' (TFEM) proposed by Tamma and Railkar (1987 and 1988) for the analysis of linear and nonlinear heat-transfer problems is described and demonstrated. The TFEM combines classical Galerkin and transform approaches with state-of-the-art FEMs to obtain a flexible hybrid modeling scheme. The fundamental principles of the TFEM and the derivation of the governing equations are reviewed, and numerical results for sample problems are presented in extensive graphs and briefly characterized. Problems analyzed include a square plate with a hole, a rectangular plate with natural and essential boundary conditions and varying thermal conductivity, the Space Shuttle thermal protection system, a bimaterial plate subjected to step temperature variations, and solidification in a semiinfinite liquid slab.

  4. Abstract models of transfinite reductions

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2010-01-01

    We investigate transfinite reductions in abstract reduction systems. To this end, we study two abstract models for transfinite reductions: a metric model generalising the usual metric approach to infinitary term rewriting and a novel partial order model. For both models we distinguish between a w...

  5. Pristine transfinite graphs and permissive electrical networks

    CERN Document Server

    Zemanian, Armen H

    2001-01-01

    A transfinite graph or electrical network of the first rank is obtained conceptually by connecting conventionally infinite graphs and networks together at their infinite extremities. This process can be repeated to obtain a hierarchy of transfiniteness whose ranks increase through the countable ordinals. This idea, which is of recent origin, has enriched the theories of graphs and networks with radically new constructs and research problems. The book provides a more accessible introduction to the subject that, though sacrificing some generality, captures the essential ideas of transfiniteness for graphs and networks. Thus, for example, some results concerning discrete potentials and random walks on transfinite networks can now be presented more concisely. Conversely, the simplifications enable the development of many new results that were previously unavailable. Topics and features: *A simplified exposition provides an introduction to transfiniteness for graphs and networks.*Various results for conventional g...

  6. Transfinite Numbers-What is Infinity?

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 3. Transfinite Numbers - What is Infinity? S M Srivastava. General Article Volume 2 Issue 3 March 1997 pp 58-68. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/002/03/0058-0068. Author Affiliations.

  7. Non-hermitian random matrix theory: Method of hermitian reduction

    Energy Technology Data Exchange (ETDEWEB)

    Feinberg, J. [California Univ., Santa Barbara, CA (United States). Inst. for Theoretical Physics; Zee, A. [California Univ., Santa Barbara, CA (United States). Inst. for Theoretical Physics]|[Institute for Advanced Study, Olden Lane, Princeton, NJ 08540 (United States)

    1997-11-03

    We consider random non-hermitian matrices in the large-N limit. The power of analytic function theory cannot be brought to bear directly to analyze non-hermitian random matrices, in contrast to hermitian random matrices. To overcome this difficulty, we show that associated to each ensemble of non-hermitian matrices there is an auxiliary ensemble of random hermitian matrices which can be analyzed by the usual methods. We then extract the Green function and the density of eigenvalues of the non-hermitian ensemble from those of the auxiliary ensemble. We apply this ``method of hermitization`` to several examples, and discuss a number of related issues. (orig.). 25 refs.

  8. Entanglement in non-Hermitian quantum theory

    Indian Academy of Sciences (India)

    quantum theory. Furthermore, we will show how to create entanglement between two. PT qubits using non-Hermitian Hamiltonians and discuss the entangling capability of such interaction Hamiltonians that are non-Hermitian in nature. Keywords. Entanglement; non-Hermitian Hamiltonians; PT symmetry. PACS Nos 03.65.

  9. Hermitian Hamiltonian equivalent to a given non-Hermitian one: manifestation of spectral singularity.

    Science.gov (United States)

    Samsonov, Boris F

    2013-04-28

    One of the simplest non-Hermitian Hamiltonians, first proposed by Schwartz in 1960, that may possess a spectral singularity is analysed from the point of view of the non-Hermitian generalization of quantum mechanics. It is shown that the η operator, being a second-order differential operator, has supersymmetric structure. Asymptotic behaviour of the eigenfunctions of a Hermitian Hamiltonian equivalent to the given non-Hermitian one is found. As a result, the corresponding scattering matrix and cross section are given explicitly. It is demonstrated that the possible presence of a spectral singularity in the spectrum of the non-Hermitian Hamiltonian may be detected as a resonance in the scattering cross section of its Hermitian counterpart. Nevertheless, just at the singular point, the equivalent Hermitian Hamiltonian becomes undetermined.

  10. The Hermitian -Conjugate Generalized Procrustes Problem

    Directory of Open Access Journals (Sweden)

    Hai-Xia Chang

    2013-01-01

    Full Text Available We consider the Hermitian -conjugate generalized Procrustes problem to find Hermitian -conjugate matrix such that is minimum, where , , , and (, are given complex matrices, and and are positive integers. The expression of the solution to Hermitian -conjugate generalized Procrustes problem is derived. And the optimal approximation solution in the solution set for Hermitian -conjugate generalized Procrustes problem to a given matrix is also obtained. Furthermore, we establish necessary and sufficient conditions for the existence and the formula for Hermitian -conjugate solution to the linear system of complex matrix equations , , ( and are positive integers. The representation of the corresponding optimal approximation problem is presented. Finally, an algorithm for solving two problems above is proposed, and the numerical examples show its feasibility.

  11. Faster than Hermitian Time Evolution

    Directory of Open Access Journals (Sweden)

    Carl M. Bender

    2007-12-01

    Full Text Available For any pair of quantum states, an initial state $|I angle$ and afinal quantum state $|F angle$, in a Hilbert space, there are many Hamiltonians $H$ under which $|I angle$ evolves into $|F angle$. Let us impose the constraint that the difference between the largest and smallest eigenvalues of $H$, $E_{max}$ and $E_{min}$, is held fixed. We can then determine the Hamiltonian $H$ that satisfies this constraint and achieves the transformation from the initial state to the final state in the least possible time $au$. For Hermitian Hamiltonians, $au$ has a nonzero lower bound. However, amongnon-Hermitian ${cal PT}$-symmetric Hamiltonians satisfying the same energy constraint, $au$ can be made arbitrarily small without violating the time-energy uncertainty principle. The minimum value of $au$ can be made arbitrarily small because for ${cal PT}$-symmetric Hamiltonians the path from the vector $|I angle$ to the vector $|F angle$, as measured using the Hilbert-space metric appropriate for this theory, can be made arbitrarily short. The mechanism described here is similar to that in general relativity in whichthe distance between two space-time points can be made small if they are connected by a wormhole. This result may have applications in quantum computing.

  12. Some remarks on quasi-Hermitian operators

    Energy Technology Data Exchange (ETDEWEB)

    Antoine, Jean-Pierre, E-mail: jean-pierre.antoine@uclouvain.be [Institut de Recherche en Mathématique et Physique, Université Catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Trapani, Camillo, E-mail: camillo.trapani@unipa.it [Dipartimento di Matematica e Informatica, Università di Palermo, I-90123, Palermo (Italy)

    2014-01-15

    A quasi-Hermitian operator is an operator that is similar to its adjoint in some sense, via a metric operator, i.e., a strictly positive self-adjoint operator. Whereas those metric operators are in general assumed to be bounded, we analyze the structure generated by unbounded metric operators in a Hilbert space. Following our previous work, we introduce several generalizations of the notion of similarity between operators. Then we explore systematically the various types of quasi-Hermitian operators, bounded or not. Finally, we discuss their application in the so-called pseudo-Hermitian quantum mechanics.

  13. Hessian equations on closed Hermitian manifolds

    OpenAIRE

    Zhang, Dekai

    2015-01-01

    In this paper, using the technical tools in \\cite{TW5}, we solve the complex Hessian equation on closed Hermitian manifolds, which generalizes the the K\\"ahler case results in \\cite{HMW} and \\cite{DK}.

  14. A Lambda Calculus for Transfinite Arrays: Unifying Arrays and Streams

    OpenAIRE

    Sinkarovs, Artjoms; Scholz, Sven-Bodo

    2017-01-01

    Array programming languages allow for concise and generic formulations of numerical algorithms, thereby providing a huge potential for program optimisation such as fusion, parallelisation, etc. One of the restrictions that these languages typically have is that the number of elements in every array has to be finite. This means that implementing streaming algorithms in such languages requires new types of data structures, with operations that are not immediately compatible with existing array ...

  15. Decoding Hermitian Codes with Sudan's Algorithm

    DEFF Research Database (Denmark)

    Høholdt, Tom; Nielsen, Rasmus Refslund

    1999-01-01

    We present an efficient implementation of Sudan's algorithm for list decoding Hermitian codes beyond half the minimum distance. The main ingredients are an explicit method to calculate so-called increasing zero bases, an efficient interpolation algorithm for finding the Q-polynomial, and a reduct......We present an efficient implementation of Sudan's algorithm for list decoding Hermitian codes beyond half the minimum distance. The main ingredients are an explicit method to calculate so-called increasing zero bases, an efficient interpolation algorithm for finding the Q...

  16. Quantum entropy of non-Hermitian entangled systems

    Science.gov (United States)

    Zhang, Shi-Yang; Fang, Mao-Fa; Xu, Lan

    2017-10-01

    Non-Hermitian Hamiltonians are an effective tool for describing the dynamics of open quantum systems. Previous research shows that the restrictions of conventional quantum mechanics may be violated in the non-Hermitian cases. We studied the entropy of a system of entangled qubits governed by a local non-Hermitian Hamiltonian operator. We find that local non-Hermitian operation influences the entropies of the two subsystems equally and simultaneously. This indicates that non-Hermitian operators possess the property of non-locality, which makes information exchange possible between subsystems. These information exchanges reduce the uncertainty of outcomes associated with two incompatible quantum measurements.

  17. Transfinite Numbers

    Indian Academy of Sciences (India)

    How many points are there on a line? Which is more in number- points on a line or lines in a plane? These are some natural questions that have occurred to us sometime or the other. It is interesting to note the difference between the two questions. Do we have to know how many points and lines there are to answer.

  18. Entanglement in non-Hermitian quantum theory

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 73; Issue 3. Entanglement in non-Hermitian quantum theory. Arun K Pati. Volume 73 Issue 3 ... Entanglement is one of the key features of quantum world that has no classical counterpart. This arises due to the linear superposition principle and the tensor product ...

  19. Equivariant embeddings of Hermitian symmetric spaces

    Indian Academy of Sciences (India)

    E-mail: Laurent.Clozel@math.u-psud.fr. MS received 28 November 2006; revised 3 April 2007. Abstract. We prove that equivariant, holomorphic embeddings of Hermitian symmetric spaces are totally geodesic (when the image is not of exceptional type). Keywords. Complex variables; metric geometry (symmetric spaces). 1.

  20. Pseudo-Hermitian quantum mechanics with unbounded metric operators.

    Science.gov (United States)

    Mostafazadeh, Ali

    2013-04-28

    I extend the formulation of pseudo-Hermitian quantum mechanics to η(+)-pseudo-Hermitian Hamiltonian operators H with an unbounded metric operator η(+). In particular, I give the details of the construction of the physical Hilbert space, observables and equivalent Hermitian Hamiltonian for the case that H has a real and discrete spectrum and its eigenvectors belong to the domain of η(+) and consequently √η(+).

  1. Linear Quantum Entropy and Non-Hermitian Hamiltonians

    Directory of Open Access Journals (Sweden)

    Alessandro Sergi

    2016-12-01

    Full Text Available We consider the description of open quantum systems with probability sinks (or sources in terms of general non-Hermitian Hamiltonians. Within such a framework, we study novel possible definitions of the quantum linear entropy as an indicator of the flow of information during the dynamics. Such linear entropy functionals are necessary in the case of a partially Wigner-transformed non-Hermitian Hamiltonian (which is typically useful within a mixed quantum-classical representation. Both the case of a system represented by a pure non-Hermitian Hamiltonian as well as that of the case of non-Hermitian dynamics in a classical bath are explicitly considered.

  2. Exact analytical solutions for time-dependent Hermitian Hamiltonian systems from static unobservable non-Hermitian Hamiltonians

    Science.gov (United States)

    Fring, Andreas; Frith, Thomas

    2017-01-01

    We propose a procedure to obtain exact analytical solutions to the time-dependent Schrödinger equations involving explicit time-dependent Hermitian Hamiltonians from solutions to time-independent non-Hermitian Hamiltonian systems and the time-dependent Dyson relation, together with the time-dependent quasi-Hermiticity relation. We illustrate the working of this method for a simple Hermitian Rabi-type model by relating it to a non-Hermitian time-independent system corresponding to the one-site lattice Yang-Lee model.

  3. Measuring non-Hermitian operators via weak values

    Science.gov (United States)

    Pati, Arun Kumar; Singh, Uttam; Sinha, Urbasi

    2015-11-01

    In quantum theory, a physical observable is represented by a Hermitian operator as it admits real eigenvalues. This stems from the fact that any measuring apparatus that is supposed to measure a physical observable will always yield a real number. However, the reality of an eigenvalue of some operator does not mean that it is necessarily Hermitian. There are examples of non-Hermitian operators that may admit real eigenvalues under some symmetry conditions. In general, given a non-Hermitian operator, its average value in a quantum state is a complex number and there are only very limited methods available to measure it. Following standard quantum mechanics, we provide an experimentally feasible protocol to measure the expectation value of any non-Hermitian operator via weak measurements. The average of a non-Hermitian operator in a pure state is a complex multiple of the weak value of the positive-semidefinite part of the non-Hermitian operator. We also prove an uncertainty relation for any two non-Hermitian operators and show that the fidelity of a quantum state under a quantum channel can be measured using the average of the corresponding Kraus operators. The importance of our method is shown in testing the stronger uncertainty relation, verifying the Ramanujan formula, and measuring the product of noncommuting projectors.

  4. Symmetric inverse-based multilevel ILU preconditioning for solving dense complex non-hermitian systems in electromagnetics

    NARCIS (Netherlands)

    Carpentieri, B.; Bollhofer, M.

    2012-01-01

    Boundary element discretizations of exterior Maxwell problems lead to dense complex non-Hermitian systems of linear equations that are difficult to solve from a linear algebra point of view. We show that the recently developed class of inverse-based multilevel incomplete LU factorization has very

  5. Hermitian Matrix Model with Plaquette Interaction

    DEFF Research Database (Denmark)

    Chekhov, L.; Kristjansen, C.

    1996-01-01

    We study a hermitian $(n+1)$-matrix model with plaquette interaction, $\\sum_{i=1}^n MA_iMA_i$. By means of a conformal transformation we rewrite the model as an $O(n)$ model on a random lattice with a non polynomial potential. This allows us to solve the model exactly. We investigate the critical...... properties of the plaquette model and find that for $n\\in]-2,2]$ the model belongs to the same universality class as the $O(n)$ model on a random lattice....

  6. A Loomis-Sikorski theorem and functional calculus for a generalized Hermitian algebra

    Science.gov (United States)

    Foulis, David J.; Jenčová, Anna; Pulmannová, Sylvia

    2017-10-01

    A generalized Hermitian (GH-) algebra is a generalization of the partially ordered Jordan algebra of all Hermitian operators on a Hilbert space. We introduce the notion of a gh-tribe, which is a commutative GH-algebra of functions on a nonempty set X with pointwise partial order and operations, and we prove that every commutative GH-algebra is the image of a gh-tribe under a surjective GH-morphism. Using this result, we prove that each element a of a GH-algebra A corresponds to a real observable ξa on the σ-orthomodular lattice of projections in A and that ξa determines the spectral resolution of a. Also, if f is a continuous function defined on the spectrum of a, we formulate a definition of f (a), thus obtaining a continuous functional calculus for A.

  7. Enhancing parameter estimation precision by non-Hermitian operator process

    Science.gov (United States)

    Guo, You-neng; Fang, Mao-fa; Wang, Guo-you; Hang, Jiang; Zeng, Ke

    2017-12-01

    Recently, Zhong et al. (Phys Rev A 87:022337, 2013) investigated the dynamics of quantum Fisher information (QFI) in the presence of decoherence. We here reform their results and propose two schemes to enhance and preserve the QFIs for a qubit system subjected to a decoherence noisy environment by applying {non {-}Hermitian} operator process either before or after the amplitude damping noise. Resorting to the Bloch sphere representation, we derive the exact analytical expressions of the QFIs with respect to the amplitude parameter θ and the phase parameter φ , and in detail investigate the influence of {non {-}Hermitian} operator parameters on the QFIs. Compared with pure decoherence process (without non-Hermitian operator process), we find that the {post non {-}Hermitian} operator process can potentially enhance and preserve the QFIs by choosing appropriate {non {-}Hermitian} operator parameters, while with the help of the {prior non {-}Hermitian} operator process one could completely eliminate the effect of decoherence to improve the parameters estimation. Finally, a generalized non-Hermitian operator parameters effect on the parameters estimation is also discussed.

  8. Hermitian Self-Orthogonal Constacyclic Codes over Finite Fields

    Directory of Open Access Journals (Sweden)

    Amita Sahni

    2014-01-01

    Full Text Available Necessary and sufficient conditions for the existence of Hermitian self-orthogonal constacyclic codes of length n over a finite field Fq2, n coprime to q, are found. The defining sets and corresponding generator polynomials of these codes are also characterised. A formula for the number of Hermitian self-orthogonal constacyclic codes of length n over a finite field Fq2 is obtained. Conditions for the existence of numerous MDS Hermitian self-orthogonal constacyclic codes are obtained. The defining set and the number of such MDS codes are also found.

  9. Stabilizing non-Hermitian systems by periodic driving

    Science.gov (United States)

    Gong, Jiangbin; Wang, Qing-hai

    2015-04-01

    The time evolution of a system with a time-dependent non-Hermitian Hamiltonian is in general unstable with exponential growth or decay. A periodic driving field may stabilize the dynamics because the eigenphases of the associated Floquet operator may become all real. This possibility can emerge for a continuous range of system parameters with subtle domain boundaries. It is further shown that the issue of stability of a driven non-Hermitian Rabi model can be mapped onto the band structure problem of a class of lattice Hamiltonians. As a straightforward application, we show how to use the stability of driven non-Hermitian two-level systems (0 dimension in space) to simulate a spectrum analogous to Hofstadter's butterfly that has played a paradigmatic role in quantum Hall physics. The simulation of the band structure of non-Hermitian superlattice potentials with parity-time reversal symmetry is also briefly discussed.

  10. Improved Power Decoding of One-Point Hermitian Codes

    DEFF Research Database (Denmark)

    Puchinger, Sven; Bouw, Irene; Rosenkilde, Johan Sebastian Heesemann

    2017-01-01

    We propose a new partial decoding algorithm for one-point Hermitian codes that can decode up to the same number of errors as the Guruswami–Sudan decoder. Simulations suggest that it has a similar failure probability as the latter one. The algorithm is based on a recent generalization of the power...... decoding algorithm for Reed–Solomon codes and does not require an expensive root-finding step. In addition, it promises improvements for decoding interleaved Hermitian codes....

  11. A Further Note on a Formal Relationship Between the Arithmetic of Homaloidal Nets and the Dimensions of Transfinite Space-Time

    OpenAIRE

    Saniga, Metod

    2001-01-01

    A sequence of integers generated by the number of conjugated pairs of homaloidal nets of plane algebraic curves of even order is found to provide an >exact< integer-valued match for El Naschie's primordial set of fractal dimensions characterizing transfinite heterotic string space-time.

  12. Wide-range-tunable Dirac-cone band structure in a chiral-time-symmetric non-Hermitian system

    Science.gov (United States)

    Lin, S.; Song, Z.

    2017-11-01

    We establish a connection between an arbitrary Hermitian tight-binding model with chiral (C ) symmetry and its non-Hermitian counterpart with chiral-time (CT ) symmetry. We show that such a non-Hermitian Hamiltonian is pseudo-Hermitian. The eigenvalues and eigenvectors of the non-Hermitian Hamiltonian can be easily obtained from those of its parent Hermitian Hamiltonian. It provides a way to generate a class of non-Hermitian models with a tunable full real band structure by means of additional imaginary potentials. We also present an illustrative example that could achieve a cone structure from the energy band of a two-layer Hermitian square lattice model.

  13. Feshbach resonances: the branching of quantum mechanics into Hermitian and non-Hermitian formalisms.

    Science.gov (United States)

    Moiseyev, Nimrod

    2009-07-02

    As has been shown long time ago by Feshbach, the exact energy spectrum of the full problem can be obtained by solving two different self-energy problems. In spite of the fact that the two effective Hamiltonians are derived in very similar ways in one case, the exact energy spectrum of the full problem can be either real or complex (depending on the boundary conditions), whereas the exact energy spectrum associated with the second effective Hamiltonian has to be complex (excluding bound states in the continuum). The focus of this paper is on the fact that in both cases the complex eigenvalues result from the same requirement of an out-going boundary condition. The branching of quantum mechanics to standard (Hermitian) formalism and non-Hermitian formalism is associated with the decision to express the exact energy spectrum with one of the two possible self-consistent like problems where the use of the Green operator imposes an outgoing boundary condition on the solutions of the time-independent Schrodinger equation. Our analysis is made for the case where an ABC molecule has sufficient energy to dissociate to A + BC but not to A + B + C and not to AB + C or to AC + B.

  14. Ranks of a Constrained Hermitian Matrix Expression with Applications

    Directory of Open Access Journals (Sweden)

    Shao-Wen Yu

    2013-01-01

    Full Text Available We establish the formulas of the maximal and minimal ranks of the quaternion Hermitian matrix expression C4−A4XA4∗ where X is a Hermitian solution to quaternion matrix equations A1X=C1, XB1=C2, and A3XA3*=C3. As applications, we give a new necessary and sufficient condition for the existence of Hermitian solution to the system of matrix equations A1X=C1, XB1=C2, A3XA3*=C3, and A4XA4*=C4, which was investigated by Wang and Wu, 2010, by rank equalities. In addition, extremal ranks of the generalized Hermitian Schur complement C4−A4A3~A4∗ with respect to a Hermitian g-inverse A3~ of A3, which is a common solution to quaternion matrix equations A1X=C1 and XB1=C2, are also considered.

  15. Non-Hermitian localization in biological networks

    Science.gov (United States)

    Amir, Ariel; Hatano, Naomichi; Nelson, David R.

    2016-04-01

    We explore the spectra and localization properties of the N -site banded one-dimensional non-Hermitian random matrices that arise naturally in sparse neural networks. Approximately equal numbers of random excitatory and inhibitory connections lead to spatially localized eigenfunctions and an intricate eigenvalue spectrum in the complex plane that controls the spontaneous activity and induced response. A finite fraction of the eigenvalues condense onto the real or imaginary axes. For large N , the spectrum has remarkable symmetries not only with respect to reflections across the real and imaginary axes but also with respect to 90∘ rotations, with an unusual anisotropic divergence in the localization length near the origin. When chains with periodic boundary conditions become directed, with a systematic directional bias superimposed on the randomness, a hole centered on the origin opens up in the density-of-states in the complex plane. All states are extended on the rim of this hole, while the localized eigenvalues outside the hole are unchanged. The bias-dependent shape of this hole tracks the bias-independent contours of constant localization length. We treat the large-N limit by a combination of direct numerical diagonalization and using transfer matrices, an approach that allows us to exploit an electrostatic analogy connecting the "charges" embodied in the eigenvalue distribution with the contours of constant localization length. We show that similar results are obtained for more realistic neural networks that obey "Dale's law" (each site is purely excitatory or inhibitory) and conclude with perturbation theory results that describe the limit of large directional bias, when all states are extended. Related problems arise in random ecological networks and in chains of artificial cells with randomly coupled gene expression patterns.

  16. Finding of the Metric Operator for a Quasi-Hermitian Model

    Directory of Open Access Journals (Sweden)

    Ebru Ergun

    2013-01-01

    Full Text Available We consider on an appropriate Sobolev space a non-Hermitian Hamiltonian depending on the two complex parameters α and β and having real spectrum. We derive a closed formula for a family of the metric operators, which render the Hamiltonian Hermitian. In some particular cases, we calculate the Hermitian counterpart of .

  17. Random matrix theory for pseudo-Hermitian systems: Cyclic blocks

    Indian Academy of Sciences (India)

    We discuss the relevance of random matrix theory for pseudo-Hermitian systems, and, for Hamiltonians that break parity and time-reversal invariance . In an attempt to understand the random Ising model, we present the treatment of cyclic asymmetric matrices with blocks and show that the nearest-neighbour spacing ...

  18. A Boundary Value Problem for Hermitian Monogenic Functions

    Directory of Open Access Journals (Sweden)

    Ricardo Abreu Blaya

    2008-02-01

    Full Text Available We study the problem of finding a Hermitian monogenic function with a given jump on a given hypersurface in ℝm, m=2n. Necessary and sufficient conditions for the solvability of this problem are obtained.

  19. Slant Riemannian maps from almost hermitian manifolds | Sahin ...

    African Journals Online (AJOL)

    As a generalization of holomorphic submersions, anti-invariant submersions and slant submersions, we introduce slant Riemannian maps from almost Hermitian manifolds to Riemannian manifolds. We give examples, obtain the existence conditions of slant Riemannian maps and investigate harmonicity of such maps.

  20. Coherent states of non-Hermitian quantum systems

    OpenAIRE

    Roy, B.; Roy, P.

    2006-01-01

    We use the Gazeau-Klauder formalism to construct coherent states of non-Hermitian quantum systems. In particular we use this formalism to construct coherent state of a PT symmetric system. We also discuss construction of coherent states following Klauder's minimal prescription.

  1. Optical realization of relativistic non-Hermitian quantum mechanics.

    Science.gov (United States)

    Longhi, Stefano

    2010-07-02

    Light propagation in distributed-feedback optical structures with gain or loss regions is shown to provide an accessible laboratory tool to visualize in optics the spectral properties of the one-dimensional Dirac equation with non-Hermitian interactions. Spectral singularities and PT symmetry breaking of the Dirac Hamiltonian are shown to correspond to simple observable physical quantities and are related to well-known physical phenomena such as resonance narrowing and laser oscillation.

  2. Analytical results for non-Hermitian parity–time-symmetric and ...

    Indian Academy of Sciences (India)

    Abstract. We investigate both the non-Hermitian parity–time-(PT-)symmetric and Hermitian asymmetric volcano potentials, and present the analytical solution in terms of the confluent Heun function. Under certain special conditions, the confluent Heun function can be terminated as a polynomial, thereby leading to certain ...

  3. Sub-quadratic decoding of one-point hermitian codes

    DEFF Research Database (Denmark)

    Nielsen, Johan Sebastian Rosenkilde; Beelen, Peter

    2015-01-01

    We present the first two sub-quadratic complexity decoding algorithms for one-point Hermitian codes. The first is based on a fast realization of the Guruswami-Sudan algorithm using state-of-the-art algorithms from computer algebra for polynomial-ring matrix minimization. The second is a power...... decoding algorithm: an extension of classical key equation decoding which gives a probabilistic decoding algorithm up to the Sudan radius. We show how the resulting key equations can be solved by the matrix minimization algorithms from computer algebra, yielding similar asymptotic complexities....

  4. 20th International Workshop on Hermitian Symmetric Spaces and Submanifolds

    CERN Document Server

    Ohnita, Yoshihiro; Zhou, Jiazu; Kim, Byung; Lee, Hyunjin

    2017-01-01

    This book presents the proceedings of the 20th International Workshop on Hermitian Symmetric Spaces and Submanifolds, which was held at the Kyungpook National University from June 21 to 25, 2016. The Workshop was supported by the Research Institute of Real and Complex Manifolds (RIRCM) and the National Research Foundation of Korea (NRF). The Organizing Committee invited 30 active geometers of differential geometry and related fields from all around the globe to discuss new developments for research in the area. These proceedings provide a detailed overview of recent topics in the field of real and complex submanifolds.

  5. 15th International Conference on Non-Hermitian Hamiltonians in Quantum Physics

    CERN Document Server

    Passante, Roberto; Trapani, Camillo

    2016-01-01

    This book presents the Proceedings of the 15th International Conference on Non-Hermitian Hamiltonians in Quantum Physics, held in Palermo, Italy, from 18 to 23 May 2015. Non-Hermitian operators, and non-Hermitian Hamiltonians in particular, have recently received considerable attention from both the mathematics and physics communities. There has been a growing interest in non-Hermitian Hamiltonians in quantum physics since the discovery that PT-symmetric Hamiltonians can have a real spectrum and thus a physical relevance. The main subjects considered in this book include: PT-symmetry in quantum physics, PT-optics, Spectral singularities and spectral techniques, Indefinite-metric theories, Open quantum systems, Krein space methods, and Biorthogonal systems and applications. The book also provides a summary of recent advances in pseudo-Hermitian Hamiltonians and PT-symmetric Hamiltonians, as well as their applications in quantum physics and in the theory of open quantum systems.

  6. Exactly solvable PT-symmetric Hamiltonian having no Hermitian counterpart

    Science.gov (United States)

    Bender, Carl M.; Mannheim, Philip D.

    2008-07-01

    In a recent paper Bender and Mannheim showed that the unequal-frequency fourth-order derivative Pais-Uhlenbeck oscillator model has a realization in which the energy eigenvalues are real and bounded below, the Hilbert-space inner product is positive definite, and time evolution is unitary. Central to that analysis was the recognition that the Hamiltonian HPU of the model is PT symmetric. This Hamiltonian was mapped to a conventional Dirac-Hermitian Hamiltonian via a similarity transformation whose form was found exactly. The present paper explores the equal-frequency limit of the same model. It is shown that in this limit the similarity transform that was used for the unequal-frequency case becomes singular and that HPU becomes a Jordan-block operator, which is nondiagonalizable and has fewer energy eigenstates than eigenvalues. Such a Hamiltonian has no Hermitian counterpart. Thus, the equal-frequency PT theory emerges as a distinct realization of quantum mechanics. The quantum mechanics associated with this Jordan-block Hamiltonian can be treated exactly. It is shown that the Hilbert space is complete with a set of nonstationary solutions to the Schrödinger equation replacing the missing stationary ones. These nonstationary states are needed to establish that the Jordan-block Hamiltonian of the equal-frequency Pais-Uhlenbeck model generates unitary time evolution.

  7. Blind Source Separation in Farsi Language by Using Hermitian Angle in Convolutive Enviroment

    Directory of Open Access Journals (Sweden)

    Atefeh Soltani

    2013-04-01

    Full Text Available This paper presents a T-F masking method for convolutive blind source separation based on hermitian angle concept. The hermitian angle is calculated between T-F domain mixture vector and reference vector. Two different reference vectors are assumed for calculating two different hermitian angles, and then these angles are clustered with k-means or FCM method to estimate unmixing masks. The well-known permutation problem is solved based on k-means clustering of estimated masks which are partitioned to small groups. The experimental results show an improvement in performance when using two different reference vectors compared to only one.

  8. Three theorems on cosymplectic hypersurfaces of six-dimensional Hermitian submanifolds of the Cayley algebra

    Directory of Open Access Journals (Sweden)

    M. Banaru

    2003-08-01

    Full Text Available It is proved that cosymplectic hypersurfaces of six-dimensional Hermitian submanifolds of the octave algebra are ruled manifolds. A necessary and sufficient condition for a cosymplectic hypersurface of a Hermitian submanifold M6⊂O to be a minimal submanifold of M6 is established. It is also proved that a six-dimensional Hermitian submanifold M6⊂O satisfying the g-cosymplectic hypersurfaces axiom is a Kählerian manifold.

  9. Fermionic coherent states for pseudo-Hermitian two-level systems

    Energy Technology Data Exchange (ETDEWEB)

    Cherbal, O [Physical Faculty, Theoretical Physics Lab, USTHB, BP 32 El-Alia, Bab Ezzouar, 16111 Algiers (Algeria); Drir, M [Physical Faculty, Theoretical Physics Lab, USTHB, BP 32 El-Alia, Bab Ezzouar, 16111 Algiers (Algeria); Maamache, M [Laboratoire de Physique Quantique et Systemes Dynamiques, Department of Physics, Setif University, Setif 19000 (Algeria); Trifonov, D A [Institute of Nuclear Research, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria)

    2007-02-23

    We introduce creation and annihilation operators of pseudo-Hermitian fermions for two-level systems described by a pseudo-Hermitian Hamiltonian with real eigenvalues. This allows the generalization of the fermionic coherent states approach to such systems. Pseudo-fermionic coherent states are constructed as eigenstates of two pseudo-fermion annihilation operators. These coherent states form a bi-normal and bi-overcomplete system, and their evolution governed by the pseudo-Hermitian Hamiltonian is temporally stable. In terms of the introduced pseudo-fermion operators, the two-level system Hamiltonian takes a factorized form similar to that of a harmonic oscillator.

  10. Supersymmetric Extension of Non-Hermitian su(2 Hamiltonian and Supercoherent States

    Directory of Open Access Journals (Sweden)

    Omar Cherbal

    2010-12-01

    Full Text Available A new class of non-Hermitian Hamiltonians with real spectrum, which are written as a real linear combination of su(2 generators in the form H=ωJ_3+αJ_−+βJ_+, α≠β, is analyzed. The metrics which allows the transition to the equivalent Hermitian Hamiltonian is established. A pseudo-Hermitian supersymmetic extension of such Hamiltonians is performed. They correspond to the pseudo-Hermitian supersymmetric systems of the boson-phermion oscillators. We extend the supercoherent states formalism to such supersymmetic systems via the pseudo-unitary supersymmetric displacement operator method. The constructed family of these supercoherent states consists of two dual subfamilies that form a bi-overcomplete and bi-normal system in the boson-phermion Fock space. The states of each subfamily are eigenvectors of the boson annihilation operator and of one of the two phermion lowering operators.

  11. The Twisted Photon Associated to Hyper-Hermitian Four-Manifolds

    OpenAIRE

    Dunajski, Maciej

    1998-01-01

    The Lax formulation of the hyper-Hermiticity condition in four dimensions is used to derive a potential that generalises Plebanski's second heavenly equation for hyper-Kahler 4-manifolds. A class of examples of hyper-Hermitian metrics which depend on two arbitrary functions of two complex variables is given. The twistor theory of four-dimensional hyper-Hermitian manifolds is formulated as a combination of the Nonlinear Graviton Construction with the Ward transform for anti-self-dual Maxwell f...

  12. A remark on band-Toeplitz preconditions for Hermitian Toeplitz systems

    Energy Technology Data Exchange (ETDEWEB)

    Parter, S.V.; You, J. [Univ. of Wisconsin, Madison, WI (United States)

    1994-12-31

    This note presents a modification of an idea of R.H. Chan and P.T.P. Tang. Let f(0) {>=} 0 be a real valued, bounded, continuous function defined on ({minus}{pi}, {pi}). Let T{sub n}[f] be the Toeplitz matrix of order n + 1 generated by f(0). Chan and Tang suggest that for given {ell} {>=} 1 one chose g{sub {ell}}(0) {>=} 0 as a real valued function of fixed degree {ell} which minimizes a particular matrix. They construct g(0) via the Remez algorithm. Then T{sub n}[g{sub {ell}}]{sup {minus}1} is used as the precondition for T{sub n}[f]. The author suggests that g(0) be chosen as the even trigonometric polynomial of minimal degree which {open_quotes}matches{close_quotes} f(0) at all points {theta}{sub j} at which f({theta}) assumes its minimum. Clearly this g({theta}) is much easier to determine that the g{sub {ell}}({theta}). This choice is based on earlier work on the extreme eigenvalues of Hermitian Toeplitz matrices and the more recent work of Manteuffel and Parter on Preconditioning finite element discretizations of elliptic operators. It is shown that the condition number of T{sub n}[g]{sup {minus}1} T{sub N}[F] is uniformly bounded for all n. Experimental results demonstrate the efficacy of these preconditioners.

  13. A possible method for non-Hermitian and Non-PT-symmetric Hamiltonian systems.

    Directory of Open Access Journals (Sweden)

    Jun-Qing Li

    Full Text Available A possible method to investigate non-Hermitian Hamiltonians is suggested through finding a Hermitian operator η+ and defining the annihilation and creation operators to be η+ -pseudo-Hermitian adjoint to each other. The operator η+ represents the η+ -pseudo-Hermiticity of Hamiltonians. As an example, a non-Hermitian and non-PT-symmetric Hamiltonian with imaginary linear coordinate and linear momentum terms is constructed and analyzed in detail. The operator η+ is found, based on which, a real spectrum and a positive-definite inner product, together with the probability explanation of wave functions, the orthogonality of eigenstates, and the unitarity of time evolution, are obtained for the non-Hermitian and non-PT-symmetric Hamiltonian. Moreover, this Hamiltonian turns out to be coupled when it is extended to the canonical noncommutative space with noncommutative spatial coordinate operators and noncommutative momentum operators as well. Our method is applicable to the coupled Hamiltonian. Then the first and second order noncommutative corrections of energy levels are calculated, and in particular the reality of energy spectra, the positive-definiteness of inner products, and the related properties (the probability explanation of wave functions, the orthogonality of eigenstates, and the unitarity of time evolution are found not to be altered by the noncommutativity.

  14. The Metric Operator and the Functional Integral Formulation of Pseudo-Hermitian Quantum Mechanics

    Directory of Open Access Journals (Sweden)

    H. F. Jones

    2007-01-01

    Full Text Available Pseudo-Hermitian quantum theories are those in which the Hamiltonian H satisfies H† = ηHη-1, where η = e-Q is a positive-definite Hermitian operator, rather than the usual H† = H. In the operator formulation of such theories the standard Hilbert-space metric must be modified by the inclusion of η in order to ensure their probabilistic interpretation. With possible generalizations to quantum field theory in mind, it is important to ask how the functional integral formalism for pseudo-Hermitian theories differs from that of standard theories. It turns out that here Q plays quite a different role, serving primarily to implement a canonical transformation of the variables. It does not appear explicitly in the expression for the vacuum generating functional. Instead, the relation to the Hermitian theory is encoded via the dependence of Z on the external source j(t. These points are illustrated and amplified in various versions of the Swanson model, a non-Hermitian transform of the simple harmonic oscillator.

  15. Non-Hermitian time-dependent perturbation theory: Asymmetric transitions and transitionless interactions

    Science.gov (United States)

    Longhi, Stefano; Della Valle, Giuseppe

    2017-10-01

    The ordinary time-dependent perturbation theory of quantum mechanics, that describes the interaction of a stationary system with a time-dependent perturbation, predicts that the transition probabilities induced by the perturbation are symmetric with respect to the initial and final states. Here we extend time-dependent perturbation theory into the non-Hermitian realm and consider the transitions in a stationary Hermitian system, described by a self-adjoint Hamiltonian Hˆ0, induced by a time-dependent non-Hermitian interaction f(t) Hˆ1. In the weak interaction (perturbative) limit, the transition probabilities generally turn out to be asymmetric for exchange of initial and final states. In particular, for a temporal shape f(t) of the perturbation with one-sided Fourier spectrum, i.e. with only positive (or negative) frequency components, transitions are fully unidirectional, a result that holds even in the strong interaction regime. Interestingly, we show that non-Hermitian perturbations can be tailored to be transitionless, i.e. the perturbation leaves the system unchanged as if the interaction had not occurred at all, regardless the form of Hˆ0 and Hˆ1. As an application of our results, we provide important physical insights into the asymmetric (chiral) behavior of dynamical encircling of an exceptional point in two- and three-level non-Hermitian systems.

  16. Constant-intensity waves and their modulation instability in non-Hermitian potentials

    Science.gov (United States)

    Makris, K. G.; Musslimani, Z. H.; Christodoulides, D. N.; Rotter, S.

    2015-07-01

    In all of the diverse areas of science where waves play an important role, one of the most fundamental solutions of the corresponding wave equation is a stationary wave with constant intensity. The most familiar example is that of a plane wave propagating in free space. In the presence of any Hermitian potential, a wave's constant intensity is, however, immediately destroyed due to scattering. Here we show that this fundamental restriction is conveniently lifted when working with non-Hermitian potentials. In particular, we present a whole class of waves that have constant intensity in the presence of linear as well as of nonlinear inhomogeneous media with gain and loss. These solutions allow us to study the fundamental phenomenon of modulation instability in an inhomogeneous environment. Our results pose a new challenge for the experiments on non-Hermitian scattering that have recently been put forward.

  17. A 'Dysonization' scheme for identifying quasi-particles using non-Hermitian quantum mechanics.

    Science.gov (United States)

    Jones-Smith, Katherine

    2013-04-28

    Dyson analysed the low-energy excitations of a ferromagnet using a Hamiltonian that was non-Hermitian with respect to the standard inner product. This allowed for a facile rendering of these excitations (known as spin waves) as weakly interacting bosonic quasi-particles. More than 50 years later, we have the full denouement of the non-Hermitian quantum mechanics formalism at our disposal when considering Dyson's work, both technically and contextually. Here, we recast Dyson's work on ferromagnets explicitly in terms of two inner products, with respect to which the Hamiltonian is always self-adjoint, if not manifestly 'Hermitian'. Then we extend his scheme to doped anti-ferromagnets described by the t-J model, with hopes of shedding light on the physics of high-temperature superconductivity.

  18. The twisted photon associated to hyper-Hermitian four-manifolds

    Science.gov (United States)

    Dunajski, Maciej

    1999-06-01

    The Lax formulation of the hyper-Hermiticity condition in four dimensions is used to derive a pair of potentials that generalises Plebanski's second heavenly equation for hyper-Kähler four-manifolds. A class of examples of hyper-Hermitian metrics which depend on two arbitrary functions of two complex variables is given. The twistor theory of four-dimensional hyper-Hermitian manifolds is formulated as a combination of the Nonlinear Graviton Construction with the Ward transform for anti-self-dual Maxwell fields.

  19. Resolutions of Identity for Some Non-Hermitian Hamiltonians. II. Proofs

    Directory of Open Access Journals (Sweden)

    Andrey V. Sokolov

    2011-12-01

    Full Text Available This part is a continuation of the Part I where we built resolutions of identity for certain non-Hermitian Hamiltonians constructed of biorthogonal sets of their eigen- and associated functions for the spectral problem defined on entire axis. Non-Hermitian Hamiltonians under consideration are taken with continuous spectrum and the following cases are examined: an exceptional point of arbitrary multiplicity situated on a boundary of continuous spectrum and an exceptional point situated inside of continuous spectrum. In the present work the rigorous proofs are given for the resolutions of identity in both cases.

  20. Hermitian one-particle density matrix through a semiclassical gradient expansion

    Science.gov (United States)

    Bencheikh, K.; Räsänen, E.

    2016-01-01

    We carry out the semiclassical expansion of the one-particle density matrix up to the second order in {{\\hslash }}. We use the method of Grammaticos and Voros based on the Wigner transform of operators. We show that the resulting density matrix is Hermitian and idempotent in contrast with the well-known result of the semiclassical Kirzhnits expansion. Our density matrix leads to the same particle density and kinetic energy density as in the literature, and it satisfies the consistency criterion of the Euler equation. The derived Hermitian density matrix clarifies the ambiguity in the usefulness of gradient expansion approximations and might reignite the development of density functionals with semiclassical methods.

  1. Transport properties in a non-Hermitian triple-quantum-dot structure

    Science.gov (United States)

    Zhang, Lian-Lian; Gong, Wei-Jiang

    2017-06-01

    In this paper, we study the effect of PT -symmetric complex potentials on the transport properties of one non-Hermitian system, which is formed by the coupling between a triple-quantum-dot molecule and two semi-infinite leads. As a result, it is found that the PT -symmetric imaginary potentials have pronounced effects on the transport properties of such a system, including changes from antiresonance to resonance, shift of antiresonance, and occurrence of new antiresonance, which are determined by the interdot and dot-lead coupling manners. This paper can be helpful in understanding the quantum transport behaviors modified by the P T symmetry in non-Hermitian discrete systems.

  2. PREFACE: 6th International Workshop on Pseudo-Hermitian Hamiltonians in Quantum Physics

    Science.gov (United States)

    Fring, Andreas; Jones, Hugh; Znojil, Miloslav

    2008-06-01

    Attempts to understand the quantum mechanics of non-Hermitian Hamiltonian systems can be traced back to the early days, one example being Heisenberg's endeavour to formulate a consistent model involving an indefinite metric. Over the years non-Hermitian Hamiltonians whose spectra were believed to be real have appeared from time to time in the literature, for instance in the study of strong interactions at high energies via Regge models, in condensed matter physics in the context of the XXZ-spin chain, in interacting boson models in nuclear physics, in integrable quantum field theories as Toda field theories with complex coupling constants, and also very recently in a field theoretical scenario in the quantization procedure of strings on an AdS5 x S5 background. Concrete experimental realizations of these types of systems in the form of optical lattices have been proposed in 2007. In the area of mathematical physics similar non-systematic results appeared sporadically over the years. However, intensive and more systematic investigation of these types of non- Hermitian Hamiltonians with real eigenvalue spectra only began about ten years ago, when the surprising discovery was made that a large class of one-particle systems perturbed by a simple non-Hermitian potential term possesses a real energy spectrum. Since then regular international workshops devoted to this theme have taken place. This special issue is centred around the 6th International Workshop on Pseudo-Hermitian Hamiltonians in Quantum Physics held in July 2007 at City University London. All the contributions contain significant new results or alternatively provide a survey of the state of the art of the subject or a critical assessment of the present understanding of the topic and a discussion of open problems. Original contributions from non-participants were also invited. Meanwhile many interesting results have been obtained and consensus has been reached on various central conceptual issues in the

  3. Analytical results for non-Hermitian parity–time-symmetric and ...

    Indian Academy of Sciences (India)

    We investigate both the non-Hermitian parity–time-(PT-)symmetric and Hermitianasymmetric volcano potentials, and present the analytical solution in terms of the confluent Heun function. Under certain special conditions, the confluent Heun function can be terminated as a polynomial, thereby leading to certain exact ...

  4. Non-Hermitian Hamiltonians with a real spectrum and their physical ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 73; Issue 2 ... attempts to understand the role of pseudo-Hermitian and P T -symmetric Hamiltonians in modelling unitary quantum systems and elaborate on a particular physical phenomenon whose discovery originated in the study of complex scattering potentials.

  5. Non-Hermitian Hamiltonians with a real spectrum and their physical ...

    Indian Academy of Sciences (India)

    physics pp. 269–277. Non-Hermitian Hamiltonians with a real spectrum and their physical applications. ALI MOSTAFAZADEH. Department of Mathematics, Koç University, 34450 Sariyer, Istanbul, Turkey. E-mail: amostafazadeh@ku.edu.tr. Abstract. We present an evaluation of some recent attempts to understand the role of.

  6. Photonic Band Structure of Dispersive Metamaterials Formulated as a Hermitian Eigenvalue Problem

    KAUST Repository

    Raman, Aaswath

    2010-02-26

    We formulate the photonic band structure calculation of any lossless dispersive photonic crystal and optical metamaterial as a Hermitian eigenvalue problem. We further show that the eigenmodes of such lossless systems provide an orthonormal basis, which can be used to rigorously describe the behavior of lossy dispersive systems in general. © 2010 The American Physical Society.

  7. Non-Hermitian acoustic metamaterial for the complete control of sound by accessing the exceptional points

    CERN Document Server

    Zhu, Yi-Fan; Fan, Xu-Dong; Liang, Bin; Zou, Xin-Ye; Yang, Jing; Cheng, Jian-Chun

    2016-01-01

    Non-Hermitian systems always play a negative role in wave manipulations due to inherent non-conservation of energy as well as loss of information. Recently, however, there has been a paradigm shift on utilizing non-Hermitian systems to implement varied miraculous wave controlling. For example, parity-time symmetric media with well-designed loss and gain are presented to create a nontrivial effect of unidirectional diffraction, which is observed near the exceptional points (EPs) in the non-Hermitian systems. Here, we report the design and realization of non-Hermitian acoustic metamaterial (NHAM) and show that by judiciously tailoring the inherent loss, the phase and amplitude of reflection can possibly be tuned in a decoupled manner. Such decoupled tuning of phase and amplitude is closely related to the EPs. As a demonstration of functionality, we experimentally generate a high-quality acoustic hologram via NHAM. Our work may open a new degree of freedom for realizing the complete control of sound.

  8. THE PRACTICAL ANALYSIS OF FINITE ELEMENTS METHOD ERRORS

    Directory of Open Access Journals (Sweden)

    Natalia Bakhova

    2011-03-01

    Full Text Available Abstract. The most important in the practical plan questions of reliable estimations of finite elementsmethod errors are considered. Definition rules of necessary calculations accuracy are developed. Methodsand ways of the calculations allowing receiving at economical expenditures of computing work the best finalresults are offered.Keywords: error, given the accuracy, finite element method, lagrangian and hermitian elements.

  9. Bi-orthogonal approach to non-Hermitian Hamiltonians with the oscillator spectrum: Generalized coherent states for nonlinear algebras

    Science.gov (United States)

    Rosas-Ortiz, Oscar; Zelaya, Kevin

    2018-01-01

    A set of Hamiltonians that are not self-adjoint but have the spectrum of the harmonic oscillator is studied. The eigenvectors of these operators and those of their Hermitian conjugates form a bi-orthogonal system that provides a mathematical procedure to satisfy the superposition principle. In this form the non-Hermitian oscillators can be studied in much the same way as in the Hermitian approaches. Two different nonlinear algebras generated by properly constructed ladder operators are found and the corresponding generalized coherent states are obtained. The non-Hermitian oscillators can be steered to the conventional one by the appropriate selection of parameters. In such limit, the generators of the nonlinear algebras converge to generalized ladder operators that would represent either intensity-dependent interactions or multi-photon processes if the oscillator is associated with single mode photon fields in nonlinear media.

  10. A Non-Hermitian Approach to Non-Linear Switching Dynamics in Coupled Cavity-Waveguide Systems

    DEFF Research Database (Denmark)

    Heuck, Mikkel; Kristensen, Philip Trøst; Mørk, Jesper

    2012-01-01

    We present a non-Hermitian perturbation theory employing quasi-normal modes to investigate non-linear all-optical switching dynamics in a photonic crystal coupled cavity-waveguide system and compare with finite-difference-time-domain simulations.......We present a non-Hermitian perturbation theory employing quasi-normal modes to investigate non-linear all-optical switching dynamics in a photonic crystal coupled cavity-waveguide system and compare with finite-difference-time-domain simulations....

  11. Giant amplification of light in non-hermitian photonic materials (Presentation Recording)

    Science.gov (United States)

    Tureci, Hakan E.; Makris, Konstantinos G.; Ge, Li

    2015-09-01

    In photonics and quantum optics, a key challenge facing any technological application has traditionally been the mitigation of optical losses. Recent work has shown that a new class of optical materials, called Parity-Time symmetric materials, that consist of a precisely balanced distribution of loss and gain can be exploited to engineer novel functionalities for propagating and filtering electromagnetic radiation. Here we show a generic property of optical systems that feature an arbitrary distribution of loss and gain, described by non-Hermitian operators, namely that overall lossy optical systems can transiently amplify certain input signals by several orders of magnitude. We present a mathematical framework to analyze the dynamics of wave propagation in media with an arbitrary distribution of loss and gain and construct the initial conditions to engineer such non-Hermitian power amplifiers.

  12. Exact solutions for non-Hermitian Dirac-Pauli equation in an intensive magnetic field

    Science.gov (United States)

    Rodionov, V. N.

    2015-04-01

    We consider modified Dirac-Pauli equations that are entered using {{γ }5}-mass factorization, m\\to {{m}1}+/- {{γ }5}{{m}2}, of an ordinary Klein-Gordon operator. We also consider the interaction of fermions with an intensive uniform magnetic field, focusing on their (g-2) gyromagnetic factor. Due to effective research procedures, we derive the exact solutions of the enregy spectra of pseudo-Hermitian Hamiltonians, taking into account the spin of the fermions. The basic research methods are the elucidation of the new border areas of the unbroken PT symmetry of non-Hermitian Hamiltonians. In particular, it is shown that the reality energy spectrum of fermions at rest can be expressed by limiting the intensity of the magnetic field, H≤slant {{H}max }={{m}2}/(2Δ μ {{m}1}), where Δ μ is an anomalous magnetic moment of particles.

  13. Digital coherent superposition of optical OFDM subcarrier pairs with Hermitian symmetry for phase noise mitigation.

    Science.gov (United States)

    Yi, Xingwen; Chen, Xuemei; Sharma, Dinesh; Li, Chao; Luo, Ming; Yang, Qi; Li, Zhaohui; Qiu, Kun

    2014-06-02

    Digital coherent superposition (DCS) provides an approach to combat fiber nonlinearities by trading off the spectrum efficiency. In analogy, we extend the concept of DCS to the optical OFDM subcarrier pairs with Hermitian symmetry to combat the linear and nonlinear phase noise. At the transmitter, we simply use a real-valued OFDM signal to drive a Mach-Zehnder (MZ) intensity modulator biased at the null point and the so-generated OFDM signal is Hermitian in the frequency domain. At receiver, after the conventional OFDM signal processing, we conduct DCS of the optical OFDM subcarrier pairs, which requires only conjugation and summation. We show that the inter-carrier-interference (ICI) due to phase noise can be reduced because of the Hermitain symmetry. In a simulation, this method improves the tolerance to the laser phase noise. In a nonlinear WDM transmission experiment, this method also achieves better performance under the influence of cross phase modulation (XPM).

  14. The Real and Complex Hermitian Solutions to a System of Quaternion Matrix Equations with Applications

    Directory of Open Access Journals (Sweden)

    Shao-Wen Yu

    2012-01-01

    Full Text Available We establish necessary and sufficient conditions for the existence of and the expressions for the general real and complex Hermitian solutions to the classical system of quaternion matrix equations A1X=C1,XB1=C2, and  A3XA3*=C3. Moreover, formulas of the maximal and minimal ranks of four real matrices X1,X2,X3, and X4 in solution X=X1+X2i+X3j+X4k to the system mentioned above are derived. As applications, we give necessary and sufficient conditions for the quaternion matrix equations A1X=C1,XB1=C2,A3XA3*=C3, and  A4XA4*=C4 to have real and complex Hermitian solutions.

  15. Comment on "Spontaneous breaking of permutation symmetry in pseudo-Hermitian quantum mechanics"

    Science.gov (United States)

    Fernández, Francisco M.

    2017-10-01

    Li and Miao [Phys. Rev. A 85, 042110 (2012), 10.1103/PhysRevA.85.042110] proposed a non-Hermitian Hamiltonian that is neither Hermitian nor P T symmetric but exhibits real eigenvalues for some values of the model parameters. In order to explain this fact, they resorted to P T -pseudo Hermiticity and to a so-called permutation symmetry. Here we show that the spectrum of this Hamiltonian can be easily analyzed in the usual way in terms of exact or broken antiunitary symmetries that appear to be more relevant than the permutation symmetry. In addition, we show why the authors' Hamiltonian and the well-known Pais-Uhlenbeck oscillator lead to the same fourth-order differential equation for the coordinates.

  16. Reverse engineering of a nonlossy adiabatic Hamiltonian for non-Hermitian systems

    Science.gov (United States)

    Wu, Qi-Cheng; Chen, Ye-Hong; Huang, Bi-Hua; Xia, Yan; Song, Jie

    2016-11-01

    We generalize the quantum adiabatic theorem to the non-Hermitian system and build a strict adiabaticity condition to make the adiabatic evolution nonlossy when taking into account the effect of the adiabatic phase. According to the strict adiabaticity condition, the nonadiabatic couplings and the effect of the imaginary part of adiabatic phase should be eliminated as much as possible. Also, the non-Hermitian Hamiltonian reverse-engineering method is proposed for adiabatically driving an artificial quantum state. A concrete two-level system is adopted to show the usefulness of the reverse-engineering method. We obtain the desired target state by adjusting extra rotating magnetic fields at a predefined time. Furthermore, the numerical simulation shows that certain noise and dissipation in the systems are no longer undesirable but play a positive role in the scheme. Therefore, the scheme is quite useful for quantum information processing in some dissipative systems.

  17. Topological phases in the non-Hermitian Su-Schrieffer-Heeger model

    Science.gov (United States)

    Lieu, Simon

    2018-01-01

    We address the conditions required for a Z topological classification in the most general form of the non-Hermitian Su-Schrieffer-Heeger (SSH) model. Any chirally symmetric SSH model will possess a "conjugated-pseudo-Hermiticity" which we show is responsible for a quantized "complex" Berry phase. Consequently, we provide an example where the complex Berry phase of a band is used as a quantized invariant to predict the existence of gapless edge modes in a non-Hermitian model. The chirally broken, P T -symmetric model is studied; we suggest an explanation for why the topological invariant is a global property of the Hamiltonian. A geometrical picture is provided by examining eigenvector evolution on the Bloch sphere. We justify our analysis numerically and discuss relevant applications.

  18. An optimum Hamiltonian for non-Hermitian quantum evolution and the complex Bloch sphere

    Energy Technology Data Exchange (ETDEWEB)

    Nesterov, Alexander I., E-mail: nesterov@cencar.udg.m [Departamento de Fisica, CUCEI, Universidad de Guadalajara, Av. Revolucion 1500, Guadalajara, CP 44420, Jalisco (Mexico)

    2009-09-28

    For a quantum system governed by a non-Hermitian Hamiltonian, we studied the problem of obtaining an optimum Hamiltonian that generates nonunitary transformations of a given initial state into a certain final state in the smallest time tau. The analysis is based on the relationship between the states of the two-dimensional subspace of the Hilbert space spanned by the initial and final states and the points of the two-dimensional complex Bloch sphere.

  19. The Optimization on Ranks and Inertias of a Quadratic Hermitian Matrix Function and Its Applications

    Directory of Open Access Journals (Sweden)

    Yirong Yao

    2013-01-01

    Full Text Available We solve optimization problems on the ranks and inertias of the quadratic Hermitian matrix function subject to a consistent system of matrix equations and . As applications, we derive necessary and sufficient conditions for the solvability to the systems of matrix equations and matrix inequalities , and in the Löwner partial ordering to be feasible, respectively. The findings of this paper widely extend the known results in the literature.

  20. Non-Hermitian interaction representation and its use in relativistic quantum mechanics

    Czech Academy of Sciences Publication Activity Database

    Znojil, Miloslav

    2017-01-01

    Roč. 385, č. 10 (2017), s. 162-179 ISSN 0003-4916 R&D Projects: GA ČR GA16-22945S Institutional support: RVO:61389005 Keywords : unitary quantum systems * non-Hermitian version of Dirac's interaction picture * complete set of time-evolution equations * application in relativistic quantum mechanics * Klein-Gordon example with space-time-dependent mass Subject RIV: BE - Theoretical Physics Impact factor: 2.465, year: 2016

  1. Multivariable Christoffel-Darboux Kernels and Characteristic Polynomials of Random Hermitian Matrices

    Directory of Open Access Journals (Sweden)

    Hjalmar Rosengren

    2006-12-01

    Full Text Available We study multivariable Christoffel-Darboux kernels, which may be viewed as reproducing kernels for antisymmetric orthogonal polynomials, and also as correlation functions for products of characteristic polynomials of random Hermitian matrices. Using their interpretation as reproducing kernels, we obtain simple proofs of Pfaffian and determinant formulas, as well as Schur polynomial expansions, for such kernels. In subsequent work, these results are applied in combinatorics (enumeration of marked shifted tableaux and number theory (representation of integers as sums of squares.

  2. Extension of the CPT theorem to non-Hermitian Hamiltonians and unstable states

    Energy Technology Data Exchange (ETDEWEB)

    Mannheim, Philip D., E-mail: philip.mannheim@uconn.edu

    2016-02-10

    We extend the CPT theorem to quantum field theories with non-Hermitian Hamiltonians and unstable states. Our derivation is a quite minimal one as it requires only the time-independent evolution of scalar products, invariance under complex Lorentz transformations, and a non-standard but nonetheless perfectly legitimate interpretation of charge conjugation as an antilinear operator. The first of these requirements does not force the Hamiltonian to be Hermitian. Rather, it forces its eigenvalues to either be real or to appear in complex conjugate pairs, forces the eigenvectors of such conjugate pairs to be conjugates of each other, and forces the Hamiltonian to admit of an antilinear symmetry. The latter two requirements then force this antilinear symmetry to be CPT, while forcing the Hamiltonian to be real rather than Hermitian. Our work justifies the use of the CPT theorem in establishing the equality of the lifetimes of unstable particles that are charge conjugates of each other. We show that the Euclidean time path integrals of a CPT-symmetric theory must always be real. In the quantum-mechanical limit the key results of the PT symmetry program of Bender and collaborators are recovered, with the C-operator of the PT symmetry program being identified with the linear component of the charge conjugation operator.

  3. Spontaneous PT -symmetry breaking in non-Hermitian coupled-cavity array

    Science.gov (United States)

    Xing, Yan; Qi, Lu; Cao, Ji; Wang, Dong-Yang; Bai, Cheng-Hua; Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou

    2017-10-01

    We study the effects of the position of the passive and active cavities on the spontaneous parity-time- (PT -) symmetry-breaking behavior in a non-Hermitian coupled-cavity-array model. We analyze and discuss the energy eigenvalue spectra and PT symmetry in the topologically trivial and nontrivial regimes under three different cases in detail; that is, the passive and active cavities are located at, respectively, the two end positions, the second and penultimate positions, and each position in the coupled-cavity array. The odevity of the number of cavities is further considered to check the effects of the non-Hermitian terms applied on the PT -symmetric and -asymmetric systems. We find that the position of the passive and active cavities has remarkable impacts on the spontaneous PT -symmetry-breaking behavior, and in each case the system exhibits distinguishable and novel spontaneous PT -symmetry-breaking characteristics. The effects of the non-Hermitian terms on the PT -symmetric and -asymmetric systems due to the odevity are comparatively different in the first case but qualitatively the same in the second case.

  4. Observation of exceptional points in reconfigurable non-Hermitian vector-field holographic lattices

    Science.gov (United States)

    Hahn, Choloong; Choi, Youngsun; Yoon, Jae Woong; Song, Seok Ho; Oh, Cha Hwan; Berini, Pierre

    2016-07-01

    Recently, synthetic optical materials represented via non-Hermitian Hamiltonians have attracted significant attention because of their nonorthogonal eigensystems, enabling unidirectionality, nonreciprocity and unconventional beam dynamics. Such systems demand carefully configured complex optical potentials to create skewed vector spaces with a desired metric distortion. In this paper, we report optically generated non-Hermitian photonic lattices with versatile control of real and imaginary sub-lattices. In the proposed method, such lattices are generated by vector-field holographic interference of two elliptically polarized pump beams on azobenzene-doped polymer thin films. We experimentally observe violation of Friedel's law of diffraction, indicating the onset of complex lattice formation. We further create an exact parity-time symmetric lattice to demonstrate totally asymmetric diffraction at the spontaneous symmetry-breaking threshold, referred to as an exceptional point. On this basis, we provide the experimental demonstration of reconfigurable non-Hermitian photonic lattices in the optical domain and observe the purest exceptional point ever reported to date.

  5. Non-Hermitian engineering of synthetic saturable absorbers

    CERN Document Server

    Teimourpour, M H; Srinivasan, K; El-Ganainy, R

    2016-01-01

    We introduce a new type of synthetic saturable absorbers based on quantum inspired photonic arrays whose linear light transport characteristics can be derived via bosonic algebra. We demonstrate that the interplay between optical Kerr nonlinearity, interference effects and non-Hermiticity through radiation loss leads to a nonlinear optical filtering response with two distinct regimes of small and large optical transmissions. More interestingly, we show that the boundary between these two regimes can be very sharp. The threshold optical intensity that marks this abrupt "phase transition" and its steepness can be engineered by varying the number of the guiding elements. The practical feasibility of these structures as well as their potential applications in laser systems and optical signal processing are also discussed.

  6. Broadband and wide-angle nonreciprocity with a non-Hermitian metamaterial

    Science.gov (United States)

    Barton, David R.; Alaeian, Hadiseh; Lawrence, Mark; Dionne, Jennifer

    2018-01-01

    We theoretically demonstrate a non-Hermitian metamaterial exhibiting broadband and wide-angle nonreciprocity. The metamaterial consists of planar metal-dielectric layers with a parity-time (PT ) symmetric distribution of loss and gain. With increasing loss and gain, the band structure and band gap are strongly modified; further, the PT potential leads to distinct internal field distributions when illuminated from different sides. Including nonlinearities arising from natural loss and gain saturation leads to nonreciprocal transmission in the visible over a 50-nm wavelength and ±60∘ angular range.

  7. Problem of the coexistence of several non-Hermitian observables in PT -symmetric quantum mechanics

    Science.gov (United States)

    Znojil, Miloslav; Semorádová, Iveta; Růžička, František; Moulla, Hafida; Leghrib, Ilhem

    2017-04-01

    During recent developments in quantum theory it has been clarified that observable quantities (such as energy and position) may be represented by operators Λ (with real spectra) that are manifestly non-Hermitian in a preselected friendly Hilbert space H(F ). The consistency of these models is known to require an upgrade of the inner product, i.e., mathematically speaking, a transition H(F )→H(S ) to another, standard, Hilbert space. We prove that whenever we are given more than one candidate for an observable (i.e., say, two operators Λ0 and Λ1) in advance, such an upgrade need not exist in general.

  8. Non-Hermitian Acoustic Metamaterials: the role of Exceptional Points in sound absorption

    CERN Document Server

    Achilleos, V; Richoux, O; Pagneux, V

    2016-01-01

    Effective non-Hermitian Hamiltonians are obtained to describe coherent perfect absorbing and lasing boundary conditions. PT -symmetry of the Hamiltonians enables to design configurations which perfectly absorb at multiple frequencies. Broadened and flat perfect absorption is predicted at the exceptional point of PT -symmetry breaking while, for a particular case, absorption is enhanced with the use of gain. The aforementioned phenomena are illustrated for acoustic scattering through Helmholtz resonators revealing how tailoring the non-Hermiticity of acoustic metamaterials leads to novel mechanisms for enhanced absorption.

  9. Hermitian (ϵ,δ-Freudenthal-Kantor Triple Systems and Certain Applications of *-Generalized Jordan Triple Systems to Field Theory

    Directory of Open Access Journals (Sweden)

    Noriaki Kamiya

    2014-01-01

    Full Text Available We define Hermitian (ϵ,δ-Freudenthal-Kantor triple systems and prove a structure theorem. We also give some examples of triple systems that are generalizations of the u(N⊕u(M and sp(2N⊕u(1 Hermitian 3-algebras. We apply a *-generalized Jordan triple system to a field theory and obtain a Chern-Simons gauge theory. We find that the novel Higgs mechanism works, where the Chern-Simons gauge theory reduces to a Yang-Mills theory in a certain limit.

  10. Adiabatic approximation for the evolution generated by an A-uniformly pseudo-Hermitian Hamiltonian

    Science.gov (United States)

    Wang, Wenhua; Cao, Huaixin; Chen, Zhengli

    2017-09-01

    We discuss an adiabatic approximation for the evolution generated by an A-uniformly pseudo-Hermitian Hamiltonian H(t). Such a Hamiltonian is a time-dependent operator H(t) similar to a time-dependent Hermitian Hamiltonian G(t) under a time-independent invertible operator A. Using the relation between the solutions of the evolution equations H(t) and G(t), we prove that H(t) and H† (t) have the same real eigenvalues and the corresponding eigenvectors form two biorthogonal Riesz bases for the state space. For the adiabatic approximate solution in case of the minimum eigenvalue and the ground state of the operator H(t), we prove that this solution coincides with the system state at every instant if and only if the ground eigenvector is time-independent. We also find two upper bounds for the adiabatic approximation error in terms of the norm distance and in terms of the generalized fidelity. We illustrate the obtained results with several examples.

  11. Resolutions of Identity for Some Non-Hermitian Hamiltonians. I. Exceptional Point in Continuous Spectrum

    Directory of Open Access Journals (Sweden)

    Alexander A. Andrianov

    2011-12-01

    Full Text Available Resolutions of identity for certain non-Hermitian Hamiltonians constructed from biorthogonal sets of their eigen- and associated functions are given for the spectral problem defined on entire axis. Non-Hermitian Hamiltonians under consideration possess the continuous spectrum and the following peculiarities are investigated: (1 the case when there is an exceptional point of arbitrary multiplicity situated on a boundary of continuous spectrum; (2 the case when there is an exceptional point situated inside of continuous spectrum. The reductions of the derived resolutions of identity under narrowing of the classes of employed test functions are revealed. It is shown that in the case (1 some of associated functions included into the resolution of identity are normalizable and some of them may be not and in the case (2 the bounded associated function corresponding to the exceptional point does not belong to the physical state space. Spectral properties of a SUSY partner Hamiltonian for the Hamiltonian with an exceptional point are examined.

  12. Rapidly oscillating scatteringless non-Hermitian potentials and the absence of Kapitza stabilization

    Science.gov (United States)

    Longhi, S.

    2017-04-01

    In the framework of the ordinary non-relativistic quantum mechanics, it is known that a quantum particle in a rapidly oscillating bound potential with vanishing time average can be scattered off or even trapped owing to the phenomenon of dynamical (Kapitza) stabilization. A similar phenomenon occurs for scattering and trapping of optical waves. Such a remarkable result stems from the fact that, even though the particle is not able to follow the rapid external oscillations of the potential, these are still able to affect the average dynamics by means of an effective —albeit small— nonvanishing potential contribution. Here we consider the scattering and dynamical stabilization problem for matter or classical waves by a bound potential with oscillating ac amplitude f(t) in the framework of a non-Hermitian extension of the Schrödinger equation, and predict that for a wide class of imaginary amplitude modulations f(t) possessing a one-sided Fourier spectrum, the oscillating potential is effectively canceled, i.e., it does not have any effect on the particle dynamics, contrary to what happens in the Hermitian case.

  13. Fock model and Segal-Bargmann transform for minimal representations of Hermitian Lie groups

    DEFF Research Database (Denmark)

    Hilgert, Joachim; Kobayashi, Toshiyuki; Möllers, Jan

    2012-01-01

    For any Hermitian Lie group G of tube type we construct a Fock model of its minimal representation. The Fock space is defined on the minimal nilpotent K_C-orbit X in p_C and the L^2-inner product involves a K-Bessel function as density. Here K is a maximal compact subgroup of G, and g_C=k_C+p_C i......For any Hermitian Lie group G of tube type we construct a Fock model of its minimal representation. The Fock space is defined on the minimal nilpotent K_C-orbit X in p_C and the L^2-inner product involves a K-Bessel function as density. Here K is a maximal compact subgroup of G, and g...... intertwines the Schroedinger and Fock model. Its kernel involves the same I-Bessel function. Using the Segal--Bargmann transform we also determine the integral kernel of the unitary inversion operator in the Schroedinger model which is given by a J-Bessel function....

  14. Investigating the Composite Step Biconjugate A-Orthogonal Residual Method for Non-Hermitian Dense Linear Systems in Electromagnetics

    NARCIS (Netherlands)

    Jing, Yan-Fei; Huang, Ting-Zhu; Carpentieri, Bruno; Duan, Yong

    An interesting stabilizing variant of the biconjugate A-orthogonal residual (BiCOR) method is investigated for solving dense complex non-Hermitian systems of linear equations arising from the Galerlcin discretization of surface integral equations in electromagnetics. The novel variant is naturally

  15. Algorithm 937: MINRES-QLP for Symmetric and Hermitian Linear Equations and Least-Squares Problems.

    Science.gov (United States)

    Choi, Sou-Cheng T; Saunders, Michael A

    2014-02-01

    We describe algorithm MINRES-QLP and its FORTRAN 90 implementation for solving symmetric or Hermitian linear systems or least-squares problems. If the system is singular, MINRES-QLP computes the unique minimum-length solution (also known as the pseudoinverse solution), which generally eludes MINRES. In all cases, it overcomes a potential instability in the original MINRES algorithm. A positive-definite pre-conditioner may be supplied. Our FORTRAN 90 implementation illustrates a design pattern that allows users to make problem data known to the solver but hidden and secure from other program units. In particular, we circumvent the need for reverse communication. Example test programs input and solve real or complex problems specified in Matrix Market format. While we focus here on a FORTRAN 90 implementation, we also provide and maintain MATLAB versions of MINRES and MINRES-QLP.

  16. Morphological heart arrhythmia detection using Hermitian basis functions and kNN classifier.

    Science.gov (United States)

    Karimifard, S; Ahmadian, A; Khoshnevisan, M; Nambakhsh, M S

    2006-01-01

    This paper presents the results of morphological heart arrhythmia detection based on features of electrocardiography, ECG, signal. These signals are obtained from MIT/BIH arrhythmia database. The ECG beats were first modeled using Hermitian basis functions, (HBF). In this step, the width parameter, sigma, of HBF was optimized to minimize the model error. Then, the feature vector which consists of the parameters of the model is used as an input to k-nearest neighbor, kNN, classifier to examine the efficiency of the model. In our experiments, seven different types of arrhythmias have been considered. We achieved the sensitivity of 99.00% and specificity of 99.84% which are comparable to previous works. These results were obtained in less than 0.6 second which is suitable for real-time diagnosis of heart arrhythmias.

  17. Topological phases and edge states in a non-Hermitian trimerized optical lattice

    Science.gov (United States)

    Jin, L.

    2017-09-01

    Topologically engineered optical materials support robust light transport. Herein, the investigated non-Hermitian lattice is trimerized and inhomogeneously coupled using uniform intracell coupling. The topological properties of the coupled waveguide lattice are evaluated and we find that the PT -symmetric phase of a PT -symmetric lattice can have different topologies; the edge states depend on the lattice size, boundary configuration, and competition between the coupling and degree of non-Hermiticity. The topologically nontrivial region is extended in the presence of periodic gain and loss. The nonzero geometric phases accumulated by the Bloch bands indicate the existence of topologically protected edge states between the band gaps. The unidirectional amplification and attenuation zero modes appear above a threshold degree of non-Hermiticity, which facilitates the development of a robust optical diode.

  18. Biorthogonal quantum mechanics for non-Hermitian multimode and multiphoton Jaynes-Cummings models

    Science.gov (United States)

    Hounguevou, J. V.; Dossa, F. A.; Avossevou, G. Y. H.

    2017-10-01

    We develop a biorthogonal formalism for non-Hermitian multimode and multiphoton Jaynes-Cummings models. For these models, we define supersymmetric generators, which are especially convenient for diagonalizing the Hamiltonians. The Hamiltonian and its adjoint are expressed in terms of supersymmetric generators having the Lie superalgebra properties. The method consists in using a similarity dressing operator that maps onto spaces suitable for diagonalizing Hamiltonians even in an infinite-dimensional Hilbert space. We then successfully solve the eigenproblems related to the Hamiltonian and its adjoint. For each model, the eigenvalues are real, while the eigenstates do not form a set of orthogonal vectors. We then introduce the biorthogonality formalism to construct a consistent theory.

  19. E2-quasi-exact solvability for non-Hermitian models

    Science.gov (United States)

    Fring, Andreas

    2015-04-01

    We propose the notion of E2-quasi-exact solvability and apply this idea to find explicit solutions to the eigenvalue problem for a non-Hermitian Hamiltonian system depending on two parameters. The model considered reduces to the complex Mathieu Hamiltonian in a double scaling limit, which enables us to compute the exceptional points in the energy spectrum of the latter as a limiting process of the zeros for some algebraic equations. The coefficient functions in the quasi-exact eigenfunctions are univariate polynomials in the energy obeying a three-term recurrence relation. The latter property guarantees the existence of a linear functional such that the polynomials become orthogonal. The polynomials are shown to factorize for all levels above the quantization condition leading to vanishing norms rendering them to be weakly orthogonal. In two concrete examples we compute the explicit expressions for the Stieltjes measure.

  20. On the Hermitian Positive Definite Solutions of Nonlinear Matrix Equation Xs+A∗X−t1A+B∗X−t2B=Q

    Directory of Open Access Journals (Sweden)

    Aijing Liu

    2011-01-01

    Full Text Available Nonlinear matrix equation Xs+A∗X−t1A+B∗X−t2B=Q has many applications in engineering; control theory; dynamic programming; ladder networks; stochastic filtering; statistics and so forth. In this paper, the Hermitian positive definite solutions of nonlinear matrix equation Xs+A∗X−t1A+B∗X−t2B=Q are considered, where Q is a Hermitian positive definite matrix, A, B are nonsingular complex matrices, s is a positive number, and 0Hermitian positive definite solutions are derived. A sufficient condition for the existence of a unique Hermitian positive definite solution is given. In addition, some necessary conditions and sufficient conditions for the existence of Hermitian positive definite solutions are presented. Finally, an iterative method is proposed to compute the maximal Hermitian positive definite solution, and numerical example is given to show the efficiency of the proposed iterative method.

  1. A block variational procedure for the iterative diagonalization of non-Hermitian random-phase approximation matrices.

    Science.gov (United States)

    Rocca, Dario; Bai, Zhaojun; Li, Ren-Cang; Galli, Giulia

    2012-01-21

    We present a technique for the iterative diagonalization of random-phase approximation (RPA) matrices, which are encountered in the framework of time-dependent density-functional theory (TDDFT) and the Bethe-Salpeter equation. The non-Hermitian character of these matrices does not permit a straightforward application of standard iterative techniques used, i.e., for the diagonalization of ground state Hamiltonians. We first introduce a new block variational principle for RPA matrices. We then develop an algorithm for the simultaneous calculation of multiple eigenvalues and eigenvectors, with convergence and stability properties similar to techniques used to iteratively diagonalize Hermitian matrices. The algorithm is validated for simple systems (Na(2) and Na(4)) and then used to compute multiple low-lying TDDFT excitation energies of the benzene molecule. © 2012 American Institute of Physics

  2. Realization of the three-qubit quantum controlled gate based on matching Hermitian generators

    Science.gov (United States)

    Gautam, Kumar; Rawat, Tarun Kumar; Parthasarathy, Harish; Sharma, Navneet; Upadhyaya, Varun

    2017-05-01

    This paper deals with the design of quantum unitary gate by matching the Hermitian generators. A given complicated quantum controlled gate is approximated by perturbing a simple quantum system with a small time-varying potential. The basic idea is to evaluate the generator H_φ of the perturbed system approximately using first-order perturbation theory in the interaction picture. H_φ depends on a modulating signal φ(t){:} 0≤t≤T which modulates a known potential V. The generator H_φ of the given gate U_g is evaluated using H_g=ι log U_g. The optimal modulating signal φ(t) is chosen so that \\Vert H_g - H_φ \\Vert is a minimum. The simple quantum system chosen for our simulation is harmonic oscillator with charge perturbed by an electric field that is a constant in space but time varying and is controlled externally. This is used to approximate the controlled unitary gate obtained by perturbing the oscillator with an anharmonic term proportional to q^3. Simulations results show significantly small noise-to-signal ratio. Finally, we discuss how the proposed method is particularly suitable for designing some commonly used unitary gates. Another example was chosen to illustrate this method of gate design is the ion-trap model.

  3. Finite Element Analysis of Fluid-Conveying Timoshenko Pipes

    Directory of Open Access Journals (Sweden)

    Chih-Liang Chu

    1995-01-01

    Full Text Available A general finite element formulation using cubic Hermitian interpolation for dynamic analysis of pipes conveying fluid is presented. Both the effects of shearing deformations and rotary inertia are considered. The development retains the use of the classical four degrees-of-freedom for a two-node element. The effect of moving fluid is treated as external distributed forces on the support pipe and the fluid finite element matrices are derived from the virtual work done due to the fluid inertia forces. Finite element matrices for both the support pipe and moving fluid are derived and given explicitly. A numerical example is given to demonstrate the validity of the model.

  4. Block quasi-minimal residual iterations for non-Hermitian linear systems

    Energy Technology Data Exchange (ETDEWEB)

    Freund, R.W. [AT& T Bell Labs., Murray Hill, NJ (United States)

    1994-12-31

    Many applications require the solution of multiple linear systems that have the same coefficient matrix, but differ only in their right-hand sides. Instead of applying an iterative method to each of these systems individually, it is usually more efficient to employ a block version of the method that generates blocks of iterates for all the systems simultaneously. An example of such an iteration is the block conjugate gradient algorithm, which was first studied by Underwood and O`Leary. On parallel architectures, block versions of conjugate gradient-type methods are attractive even for the solution of single linear systems, since they have fewer synchronization points than the standard versions of these algorithms. In this talk, the author presents a block version of Freund and Nachtigal`s quasi-minimal residual (QMR) method for the iterative solution of non-Hermitian linear systems. He describes two different implementations of the block-QMR method, one based on a block version of the three-term Lanczos algorithm and one based on coupled two-term block recurrences. In both cases, the underlying block-Lanczos process still allows arbitrary normalizations of the vectors within each block, and the author discusses different normalization strategies. To maintain linear independence within each block, it is usually necessary to reduce the block size in the course of the iteration, and the author describes a deflation technique for performing this reduction. He also present some convergence results, and reports results of numerical experiments with the block-QMR method. Finally, the author discusses possible block versions of transpose-free Lanczos-based iterations such as the TFQMR method.

  5. Multi-referenced excited states and intermolecular forces from the anti-Hermitian contracted Schrodinger equation

    Science.gov (United States)

    Sturm, Erica J.

    Strong correlation due to multi-referenced electronic states of quantum chemical systems are crucial for a proper understanding of important phenomena including excited states, bond breakage and formation, singlet fission and biological transport. By solving for the 2-electron reduced density matrix (2-RDM) directly via the anti-Hermitian contracted Schrodinger equation (ACSE) we provide a balanced treatment of single and multi-referenced correlation effects without utilizing the N-electron wave function. This significantly reduces the computational expense while still maintaining near full configuration interaction accuracy when available. When provided with an initial 2-RDM guess from an active-space multi-configuration self consistent field wave function the ACSE scales as [special characters omitted] where ra is the number of active molecular orbitals (MOs) and ra is the number of external MOs. This work demonstrates the energetic accuracy of ACSE calculations with several small multi-referenced systems and presents a novel approach for investigating intermolecular interactions, using a simple dimer test case. In this monomer-optimized basis set approach we compute each monomer's properties in isolation and obtain a set of natural orbitals that best describe the monomer. We then remove or truncate orbitals deemed excessive as a function of occupation number, defining a monomer molecular orbital basis uniquely suited to that monomer. Combining two such monomers yields a super-system expressed in the monomer basis which we then rotate to a dimer basis at a desired geometry before creating a new initial 2-RDM for the final optimization by an ACSE calculation. It is found that the intermolecular properties calculated in this fashion from larger atomic basis sets maintain their high accuracy but at a fraction of the computational cost. Furthermore this basis set optimization is free of basis set superposition error, circumventing the need for an expensive

  6. On conjugate gradient type methods and polynomial preconditioners for a class of complex non-Hermitian matrices

    Science.gov (United States)

    Freund, Roland

    1988-01-01

    Conjugate gradient type methods are considered for the solution of large linear systems Ax = b with complex coefficient matrices of the type A = T + i(sigma)I where T is Hermitian and sigma, a real scalar. Three different conjugate gradient type approaches with iterates defined by a minimal residual property, a Galerkin type condition, and an Euclidian error minimization, respectively, are investigated. In particular, numerically stable implementations based on the ideas behind Paige and Saunder's SYMMLQ and MINRES for real symmetric matrices are proposed. Error bounds for all three methods are derived. It is shown how the special shift structure of A can be preserved by using polynomial preconditioning. Results on the optimal choice of the polynomial preconditioner are given. Also, some numerical experiments for matrices arising from finite difference approximations to the complex Helmholtz equation are reported.

  7. Topologically Protected Defect States in Open Photonic Systems with Non-Hermitian Charge-Conjugation and Parity-Time Symmetry.

    Science.gov (United States)

    Malzard, Simon; Poli, Charles; Schomerus, Henning

    2015-11-13

    We show that topologically protected defect states can exist in open (leaky or lossy) systems even when these systems are topologically trivial in the closed limit. The states appear from within the continuum, thus in the absence of a band gap, and are generated via exceptional points (a spectral transition that occurs in open wave and quantum systems with a generalized time-reversal symmetry), or via a degeneracy induced by charge-conjugation symmetry (which is related to the pole transition of Majorana zero modes). We demonstrate these findings for a leaking passive coupled-resonator optical waveguide with asymmmetric internal scattering, where the required symmetries (non-Hermitian versions of time-reversal symmetry, chirality, and charge conjugation) emerge dynamically.

  8. The BL-QMR algorithm for non-Hermitian linear systems with multiple right-hand sides

    Energy Technology Data Exchange (ETDEWEB)

    Freund, R.W. [AT& T Bell Labs., Murray Hill, NJ (United States)

    1996-12-31

    Many applications require the solution of multiple linear systems that have the same coefficient matrix, but differ in their right-hand sides. Instead of applying an iterative method to each of these systems individually, it is potentially much more efficient to employ a block version of the method that generates iterates for all the systems simultaneously. However, it is quite intricate to develop robust and efficient block iterative methods. In particular, a key issue in the design of block iterative methods is the need for deflation. The iterates for the different systems that are produced by a block method will, in general, converge at different stages of the block iteration. An efficient and robust block method needs to be able to detect and then deflate converged systems. Each such deflation reduces the block size, and thus the block method needs to be able to handle varying block sizes. For block Krylov-subspace methods, deflation is also crucial in order to delete linearly and almost linearly dependent vectors in the underlying block Krylov sequences. An added difficulty arises for Lanczos-type block methods for non-Hermitian systems, since they involve two different block Krylov sequences. In these methods, deflation can now occur independently in both sequences, and consequently, the block sizes in the two sequences may become different in the course of the iteration, even though they were identical at the beginning. We present a block version of Freund and Nachtigal`s quasi-minimal residual method for the solution of non-Hermitian linear systems with single right-hand sides.

  9. One-Parametric Family of the Double-Scaling Limits in the Hermitian Matrix Model $\\Phi^6:$ Onset of Nondissipative Shock Waves

    OpenAIRE

    Kudashev, Vadim R.; Suleimanov, Bulat I.

    1998-01-01

    We construct a one-parametric family of the double-scaling limits in the hermitian matrix model $\\Phi^6$ for 2D quantum gravity. The known limit of Bresin, Marinari and Parisi belongs to this family. The family is represented by the Gurevich-Pitaevskii solution of the Korteveg-de Vries equation which describes the onset of nondissipative shock waves in media with small dispersion. Numerical simulation of the universal Gurevich-Pitaevskii solution is made.

  10. Non-Hermitian random matrix theory: summation of planar diagrams, the 'single-ring' theorem and the disc-annulus phase transition

    Energy Technology Data Exchange (ETDEWEB)

    Feinberg, Joshua [Physics Department, University of Haifa at Oranim, Tivon 36006 (Israel); Physics Department, Technion, Israel Institute of Technology, Haifa 32000 (Israel)

    2006-08-11

    I review aspects of work done in collaboration with A Zee and R Scalettar (1997 Nucl. Phys. B 504 579; 1997 Nucl. Phys. B 501 643; 2001 J. Math. Phys. 42 5718) on complex non-Hermitian random matrices. I open by explaining why the bag of tools used regularly in analysing Hermitian random matrices cannot be applied directly to analyse non-Hermitian matrices, and then introduce the method of Hermitization, which solves this problem. Then, for rotationally invariant ensembles, I derive a master equation for the average density of eigenvalues in the complex plane, in the limit of infinitely large matrices. This is achieved by resumming all the planar diagrams which appear in the perturbative expansion of the Hermitized Green function. Remarkably, this resummation can be carried out explicitly for any rotationally invariant ensemble. I prove that in the limit of infinitely large matrices, the shape of the eigenvalue distribution is either a disc or an annulus. This is the celebrated 'single-ring' theorem. Which of these shapes is realized is determined by the parameters (coupling constants) which determine the ensemble. By varying these parameters a phase transition may occur between the two possible shapes. I briefly discuss the universal features of this transition. As the analysis of this problem relies heavily on summation of planar Feynman diagrams, I make a special effort at presenting a pedagogical exposition of the diagrammatic method, which some readers may find useful.

  11. Anderson localization in the non-Hermitian Aubry-André-Harper model with physical gain and loss

    Science.gov (United States)

    Zeng, Qi-Bo; Chen, Shu; Lü, Rong

    2017-06-01

    We investigate the Anderson localization in non-Hermitian Aubry-André-Harper (AAH) models with imaginary potentials added to lattice sites to represent the physical gain and loss during the interacting processes between the system and environment. By checking the mean inverse participation ratio (MIPR) of the system, we find that different configurations of physical gain and loss have very different impacts on the localization phase transition in the system. In the case with balanced physical gain and loss added in an alternate way to the lattice sites, the critical region (in the case with p -wave superconducting pairing) and the critical value (both in the situations with and without p -wave pairing) for the Anderson localization phase transition will be significantly reduced, which implies an enhancement of the localization process. However, if the system is divided into two parts with one of them coupled to physical gain and the other coupled to the corresponding physical loss, the transition process will be impacted only in a very mild way. Besides, we also discuss the situations with imbalanced physical gain and loss and find that the existence of random imaginary potentials in the system will also affect the localization process while constant imaginary potentials will not.

  12. Hermitian quark matrices

    Indian Academy of Sciences (India)

    Abstract. Assuming a relation between the quark mass matrices of the two sectors a unique solution can be obtained for the CKM flavor mixing matrix. A numerical example is worked out which is in excellent agreement with experimental data.

  13. A Hybrid Interpolation Method for Geometric Nonlinear Spatial Beam Elements with Explicit Nodal Force

    Directory of Open Access Journals (Sweden)

    Huiqing Fang

    2016-01-01

    Full Text Available Based on geometrically exact beam theory, a hybrid interpolation is proposed for geometric nonlinear spatial Euler-Bernoulli beam elements. First, the Hermitian interpolation of the beam centerline was used for calculating nodal curvatures for two ends. Then, internal curvatures of the beam were interpolated with a second interpolation. At this point, C1 continuity was satisfied and nodal strain measures could be consistently derived from nodal displacement and rotation parameters. The explicit expression of nodal force without integration, as a function of global parameters, was founded by using the hybrid interpolation. Furthermore, the proposed beam element can be degenerated into linear beam element under the condition of small deformation. Objectivity of strain measures and patch tests are also discussed. Finally, four numerical examples are discussed to prove the validity and effectivity of the proposed beam element.

  14. Contributions to the founding of the theory of transfinite numbers

    CERN Document Server

    Cantor, Georg

    1955-01-01

    One of the greatest mathematical classics of all time, this work established a new field of mathematics which was to be of incalculable importance in topology, number theory, analysis, theory of functions, etc., as well as in the entire field of modern logic. It is rare that a theory of such fundamental mathematical importance is expressed so simply and clearly: the reader with a good grasp of college mathematics will be able to understand most of the basic ideas and many of the proofs.Cantor first develops the elementary definitions and operations of cardinal and ordinal numbers and analyzes

  15. Eigenstate thermalization in the two-dimensional transverse field Ising model. II. Off-diagonal matrix elements of observables.

    Science.gov (United States)

    Mondaini, Rubem; Rigol, Marcos

    2017-07-01

    We study the matrix elements of few-body observables, focusing on the off-diagonal ones, in the eigenstates of the two-dimensional transverse field Ising model. By resolving all symmetries, we relate the onset of quantum chaos to the structure of the matrix elements. In particular, we show that a general result of the theory of random matrices, namely, the value 2 of the ratio of variances (diagonal to off-diagonal) of the matrix elements of Hermitian operators, occurs in the quantum chaotic regime. Furthermore, we explore the behavior of the off-diagonal matrix elements of observables as a function of the eigenstate energy differences and show that it is in accordance with the eigenstate thermalization hypothesis ansatz.

  16. Toxic Elements

    DEFF Research Database (Denmark)

    Hajeb, Parvaneh; Shakibazadeh, Shahram; Sloth, Jens Jørgen

    2016-01-01

    Food is considered the main source of toxic element (arsenic, cadmium, lead, and mercury) exposure to humans, and they can cause major public health effects. In this chapter, we discuss the most important sources for toxic element in food and the foodstuffs which are significant contributors...... to human exposure. The occurrence of each element in food classes from different regions is presented. Some of the current toxicological risk assessments on toxic elements, the human health effect of each toxic element, and their contents in the food legislations are presented. An overview of analytical...... techniques and challenges for determination of toxic elements in food is also given....

  17. Balancing single- and multi-reference correlation in the chemiluminescent reaction of dioxetanone using the anti-Hermitian contracted Schrödinger equation.

    Science.gov (United States)

    Greenman, Loren; Mazziotti, David A

    2011-05-07

    Direct computation of energies and two-electron reduced density matrices (2-RDMs) from the anti-Hermitian contracted Schrödinger equation (ACSE) [D. A. Mazziotti, Phys. Rev. Lett. 97, 143002 (2006)], it is shown, recovers both single- and multi-reference electron correlation in the chemiluminescent reaction of dioxetanone especially in the vicinity of the conical intersection where strong correlation is important. Dioxetanone, the light-producing moiety of firefly luciferin, efficiently converts chemical energy into light by accessing its excited-state surface via a conical intersection. Our previous active-space 2-RDM study of dioxetanone [L. Greenman and D. A. Mazziotti, J. Chem. Phys. 133, 164110 (2010)] concluded that correlating 16 electrons in 13 (active) orbitals is required for realistic surfaces without correlating the remaining (inactive) orbitals. In this paper we pursue two complementary goals: (i) to correlate the inactive orbitals in 2-RDMs along dioxetanone's reaction coordinate and compare these results with those from multireference second-order perturbation theory (MRPT2) and (ii) to assess the size of the active space-the number of correlated electrons and orbitals-required by both MRPT2 and ACSE for accurate energies and surfaces. While MRPT2 recovers very different amounts of correlation with (4,4) and (16,13) active spaces, the ACSE obtains a similar amount of correlation energy with either active space. Nevertheless, subtle differences in excitation energies near the conical intersection suggest that the (16,13) active space is necessary to determine both energetic details and properties. Strong electron correlation is further assessed through several RDM-based metrics including (i) total and relative energies, (ii) the von Neumann entropy based on the 1-electron RDM, as well as the (iii) infinity and (iv) squared Frobenius norms based on the cumulant 2-RDM.

  18. Numerical solutions of magnetohydrodynamic stability of axisymmetric toroidal plasmas using cubic B-spline finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, C.Z.

    1988-12-01

    A nonvariational ideal MHD stability code (NOVA) has been developed. In a general flux coordinate (/psi/, theta, /zeta/) system with an arbitrary Jacobian, the NOVA code employs Fourier expansions in the generalized poloidal angle theta and generalized toroidal angle /zeta/ directions, and cubic-B spline finite elements in the radial /psi/ direction. Extensive comparisons with these variational ideal MHD codes show that the NOVA code converges faster and gives more accurate results. An extended version of NOVA is developed to integrate non-Hermitian eigenmode equations due to energetic particles. The set of non-Hermitian integro-differential eigenmode equations is numerically solved by the NOVA-K code. We have studied the problems of the stabilization of ideal MHD internal kink modes by hot particle pressure and the excitation of ''fishbone'' internal kink modes by resonating with the energetic particle magnetic drift frequency. Comparisons with analytical solutions show that the values of the critical ..beta../sub h/ from the analytical theory can be an order of magnitude different from those computed by the NOVA-K code. 24 refs., 11 figs., 1 tab.

  19. Element 115

    OpenAIRE

    Forsberg, Ulrika

    2016-01-01

    This thesis is devoted to detailed studies of element 115 decay chains using the highly efficient multi-coincidence alpha, electron, gamma and X-ray detector setup TASISpec at the gas-filled separator TASCA at GSI, Darmstadt, Germany. In a three-week long experiment thirty new decay chains assumed to stem from element 115 isotopes were observed together with the very first detections of gamma rays and potential X-rays from these nuclei. Paper I describes preparations in terms of optimisations...

  20. Framed primal elements

    OpenAIRE

    Debongnie, Jean-François

    1986-01-01

    Framed primal finite elements may be viewed as a generalized class of elements including conforming elements, primal hybrids, and non concorming elements passing the patch test. This systematization is illustrated on a lot of examples.

  1. Trace Elements and Residual Elements in Superalloys,

    Science.gov (United States)

    Trace elements , *Superalloys, Impurities, Nickel alloys, Refining, Refractory materials, Gases, Residuals, Porosity, Nonmetals, Metals, Metalloids, Segregation(Metallurgy), Auger electron spectroscopy, Fracture(Mechanics), Symposia

  2. Trace Elements and Health

    Science.gov (United States)

    Pettyjohn, Wayne A.

    1972-01-01

    Summarizes the effects of arsenic, lead, zinc, mercury, and cadmium on human health, indicates the sources of the elements in water, and considers the possibility of students in high schools analyzing water for trace amounts of the elements. (AL)

  3. Data Element Registry Services

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data Element Registry Services (DERS) is a resource for information about value lists (aka code sets / pick lists), data dictionaries, data elements, and EPA data...

  4. NEUTRONIC REACTOR CONTROL ELEMENT

    Science.gov (United States)

    Beaver, R.J.; Leitten, C.F. Jr.

    1962-04-17

    A boron-10 containing reactor control element wherein the boron-10 is dispersed in a matrix material is describeri. The concentration of boron-10 in the matrix varies transversely across the element from a minimum at the surface to a maximum at the center of the element, prior to exposure to neutrons. (AEC)

  5. Elements of spin motion

    Science.gov (United States)

    Fukushima, Toshio; Ishizaki, Hideharu

    1994-06-01

    For use in numerical studies of rotational motion, a set of elements is introduced for the torque-free rotational motion of a rigid body around its barycenter. The elements are defined as the initial values of a modification of the Andoyer canonical variables. A computational procedure is obtained for determining these elements from the combination of the spin angular momentum vector and a triad defining the orientation of the rigid body. A numerical experiment shows that the errors of transformation between the elements and variables are sufficiently small. The errors increase linearly with time for some elements and quadratically for some others.

  6. Rare (Earth Elements [score

    Directory of Open Access Journals (Sweden)

    Camilo Méndez

    2014-12-01

    Full Text Available Rare (Earth Elements is a cycle of works for solo piano. The cycle was inspired by James Dillon’s Book of Elements (Vol. I-V. The complete cycle will consist of 14 pieces; one for each selected rare (earth element. The chosen elements are Neodymium, Erbium, Tellurium, Hafnium, Tantalum, Technetium, Indium, Dysprosium, Lanthanium, Cerium, Europium, Terbium, Yttrium and Darmstadtium. These elements were selected due to their special atomic properties that in many cases make them extremely valuable for the development of new technologies, and also because of their scarcity. To date, only 4 works have been completed Yttrium, Technetium, Indium and Tellurium.

  7. Pseudo-Hermitian random matrix theory

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, S.C.L. [RIBFG, Variable Energy Cyclotron Centre, 1/AF Bidhan nagar, Kolkata-700 064 (India); Jain, S.R. [NPD, Bhabha Atomic Research Centre, Mumbai-400 085 (India)

    2013-02-15

    Complex extension of quantum mechanics and the discovery of pseudo-unitarily invariant random matrix theory has set the stage for a number of applications of these concepts in physics. We briefly review the basic ideas and present applications to problems in statistical mechanics where new results have become possible. We have found it important to mention the precise directions where advances could be made if further results become available. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Pseudo-Hermitian random matrix theory

    Science.gov (United States)

    Srivastava, S. C. L.; Jain, S. R.

    2013-02-01

    Complex extension of quantum mechanics and the discovery of pseudo-unitarily invariant random matrix theory has set the stage for a number of applications of these concepts in physics. We briefly review the basic ideas and present applications to problems in statistical mechanics where new results have become possible. We have found it important to mention the precise directions where advances could be made if further results become available.

  9. Pseudo-Hermitian random matrix theory

    OpenAIRE

    Srivastava, Shashi C. L.; Jain, S. R.

    2013-01-01

    Complex extension of quantum mechanics and the discovery of pseudo-unitarily invariant random matrix theory has set the stage for a number of applications of these concepts in physics. We briefly review the basic ideas and present applications to problems in statistical mechanics where new results have become possible. We have found it important to mention the precise directions where advances could be made if further results become available.

  10. Finite element procedures

    CERN Document Server

    Bathe, Klaus-Jürgen

    2015-01-01

    Finite element procedures are now an important and frequently indispensable part of engineering analyses and scientific investigations. This book focuses on finite element procedures that are very useful and are widely employed. Formulations for the linear and nonlinear analyses of solids and structures, fluids, and multiphysics problems are presented, appropriate finite elements are discussed, and solution techniques for the governing finite element equations are given. The book presents general, reliable, and effective procedures that are fundamental and can be expected to be in use for a long time. The given procedures form also the foundations of recent developments in the field.

  11. Chemistry of superheavy elements

    Energy Technology Data Exchange (ETDEWEB)

    Schaedel, M. [Japan Atomic Energy Agency, Tokai, Ibaraki (Japan). Advanced Science Research Center; GSI Helmholtz Center for Heavy Ion Research, Darmstadt (Germany)

    2012-07-01

    The chemistry of superheavy elements - or transactinides from their position in the Periodic Table - is summarized. After giving an overview over historical developments, nuclear aspects about synthesis of neutron-rich isotopes of these elements, produced in hot-fusion reactions, and their nuclear decay properties are briefly mentioned. Specific requirements to cope with the one-atom-at-a-time situation in automated chemical separations and recent developments in aqueous-phase and gas-phase chemistry are presented. Exciting, current developments, first applications, and future prospects of chemical separations behind physical recoil separators ('pre-separator') are discussed in detail. The status of our current knowledge about the chemistry of rutherfordium (Rf, element 104), dubnium (Db, element 105), seaborgium (Sg, element 106), bohrium (Bh, element 107), hassium (Hs, element 108), copernicium (Cn, element 112), and element 114 is discussed from an experimental point of view. Recent results are emphasized and compared with empirical extrapolations and with fully-relativistic theoretical calculations, especially also under the aspect of the architecture of the Periodic Table. (orig.)

  12. Stochastic finite element method with simple random elements

    OpenAIRE

    Starkloff, Hans-Jörg

    2008-01-01

    We propose a variant of the stochastic finite element method, where the random elements occuring in the problem formulation are approximated by simple random elements, i.e. random elements with only a finite number of possible values.

  13. The ends of elements

    Science.gov (United States)

    Thornton, Brett F.; Burdette, Shawn C.

    2013-05-01

    When elements 117 and 118 are finally named, should these new members of the halogen and noble gas families receive names ending in -ium as IUPAC has suggested? Brett F. Thornton and Shawn C. Burdette look at the history of element suffixes and make the case for not following this recommendation.

  14. Trace element emissions

    Energy Technology Data Exchange (ETDEWEB)

    Benson, S.A.; Erickson, T.A.; Steadman, E.N.; Zygarlicke, C.J.; Hauserman, W.B.; Hassett, D.J.

    1994-10-01

    The Energy & Environmental Research Center (EERC) is carrying out an investigation that will provide methods to predict the fate of selected trace elements in integrated gasification combined cycle (IGCC) and integrated gasification fuel cell (IGFC) systems to aid in the development of methods to control the emission of trace elements determined to be air toxics. The goal of this project is to identify the effects of critical chemical and physical transformations associated with trace element behavior in IGCC and IGFC systems. The trace elements included in this project are arsenic, chromium, cadmium, mercury, nickel, selenium, and lead. The research seeks to identify and fill, experimentally and/or theoretically, data gaps that currently exist on the fate and composition of trace elements. The specific objectives are to (1) review the existing literature to identify the type and quantity of trace elements from coal gasification systems, (2) perform laboratory-scale experimentation and computer modeling to enable prediction of trace element emissions, and (3) identify methods to control trace element emissions.

  15. Movies and Literary Elements.

    Science.gov (United States)

    Keller, Rodney D.

    Showing ten-minute movie clips can be an effective way to motivate students to read literature and to teach elements of fiction, namely plot, character, setting, symbol, irony, and theme. A clip from "And Then There Were None" may be used to teach various elements of plot, including conflict and the four types of conflict (man vs. man,…

  16. BSCW Unstructured Mixed Element Grids

    Data.gov (United States)

    National Aeronautics and Space Administration — Corase Grid: Quad Surface Faces= 9360 Tria Surface Faces= 128928 Nodes = 2869187 Total Elements = 9099201 Hex Elements = 0 Pent_5 Elements = 0 Pent_6 Elements =...

  17. Neutronic fuel element fabrication

    Science.gov (United States)

    Korton, George

    2004-02-24

    This disclosure describes a method for metallurgically bonding a complete leak-tight enclosure to a matrix-type fuel element penetrated longitudinally by a multiplicity of coolant channels. Coolant tubes containing solid filler pins are disposed in the coolant channels. A leak-tight metal enclosure is then formed about the entire assembly of fuel matrix, coolant tubes and pins. The completely enclosed and sealed assembly is exposed to a high temperature and pressure gas environment to effect a metallurgical bond between all contacting surfaces therein. The ends of the assembly are then machined away to expose the pin ends which are chemically leached from the coolant tubes to leave the coolant tubes with internal coolant passageways. The invention described herein was made in the course of, or under, a contract with the U.S. Atomic Energy Commission. It relates generally to fuel elements for neutronic reactors and more particularly to a method for providing a leak-tight metal enclosure for a high-performance matrix-type fuel element penetrated longitudinally by a multiplicity of coolant tubes. The planned utilization of nuclear energy in high-performance, compact-propulsion and mobile power-generation systems has necessitated the development of fuel elements capable of operating at high power densities. High power densities in turn require fuel elements having high thermal conductivities and good fuel retention capabilities at high temperatures. A metal clad fuel element containing a ceramic phase of fuel intimately mixed with and bonded to a continuous refractory metal matrix has been found to satisfy the above requirements. Metal coolant tubes penetrate the matrix to afford internal cooling to the fuel element while providing positive fuel retention and containment of fission products generated within the fuel matrix. Metal header plates are bonded to the coolant tubes at each end of the fuel element and a metal cladding or can completes the fuel-matrix enclosure

  18. Flow Element Models

    DEFF Research Database (Denmark)

    Heiselberg, Per; Nielsen, Peter V.

    Air distribution in ventilated rooms is a flow process that can be divided into different elements such as supply air jets, exhaust flows, thermal plumes, boundary layer flows, infiltration and gravity currents. These flow elements are isolated volumes where the air movement is controlled...... by a restricted number of parameters, and the air movement is fairly independent of the general flow in the enclosure. In many practical situations, the most convenient· method is to design the air distribution system using flow element theory....

  19. The solar element

    DEFF Research Database (Denmark)

    Kragh, Helge

    2009-01-01

    of the nineteenth century. In the modest form of a yellow spectral line known as D3, 'helium' was sometimes supposed to exist in the Sun's atmosphere, an idea which is traditionally ascribed to J. Norman Lockyer. Did Lockyer discover helium as a solar element? How was the suggestion received by chemists, physicists...... and astronomers in the period until the spring of 1895, when William Ramsay serendipitously found the gas in uranium minerals? The hypothetical element helium was fairly well known, yet Ramsay's discovery owed little or nothing to Lockyer's solar element. Indeed, for a brief while it was thought that the two...

  20. Elements in biological AMS

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, J.S.; McAninch, J.; Freeman, S.

    1996-08-01

    AMS (Accelerator Mass Spectrometry) provides high detection sensitivity for isotopes whose half-lives are between 10 years and 100 million years. {sup 14}C is the most developed of such isotopes and is used in tracing natural and anthropogenic organic compounds in the Earth`s biosphere. Thirty-three elements in the main periodic table and 17 lanthanides or actinides have long lived isotopes, providing potential tracers for research in elemental biochemistry. Overlap of biologically interesting heavy elements and possible AMS tracers is discussed.

  1. Discovery of element 112

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, S. [GSI, Darmstadt (Germany)

    1996-12-31

    The new elements 110, 111, and 112 were synthesized and unambiguously identified in experiments at SHIP. Due to strong shell effects the dominant decay mode is not fission, but emission of alpha particles. Theoretical investigations predict that maximum shell effects should exist in nuclei near proton number 114 and neutron number 184. Measurements give hope that isotopes of element 114 close to the island of spherical Superheavy Elements could be produced by fusion reactions using {sup 118}Pb as target. systematic studies of the reaction cross-sections indicate that transfer of nucleons is the important process to initiate the fusion.

  2. Multi-Element Airfoil System

    Science.gov (United States)

    Turner, Travis L. (Inventor); Khorrami, Mehdi R. (Inventor); Lockard, David P. (Inventor); McKenney, Martin J. (Inventor); Atherley, Raymond D. (Inventor); Kidd, Reggie T. (Inventor)

    2014-01-01

    A multi-element airfoil system includes an airfoil element having a leading edge region and a skin element coupled to the airfoil element. A slat deployment system is coupled to the slat and the skin element, and is capable of deploying and retracting the slat and the skin element. The skin element substantially fills the lateral gap formed between the slat and the airfoil element when the slat is deployed. The system further includes an uncoupling device and a sensor to remove the skin element from the gap based on a critical angle-of-attack of the airfoil element. The system can alternatively comprise a trailing edge flap, where a skin element substantially fills the lateral gap between the flap and the trailing edge region of the airfoil element. In each case, the skin element fills a gap between the airfoil element and the deployed flap or slat to reduce airframe noise.

  3. Divergent picornavirus IRES elements

    DEFF Research Database (Denmark)

    Belsham, Graham

    2009-01-01

    Internal ribosome entry site (IRES) elements were first identified about 20 years ago within the 5' untranslated region of picornavirus RNAs. They direct a cap-independent mechanism of translation initiation on the viral RNA. Within the picornavirus family it is now known that there are four...... classes of IRES element which vary in size (450-270nt), they also have different, complex, secondary structures and distinct requirements for cellular proteins to allow them to function. This review describes the features of each class of picornavirus IRES element but focuses on the characteristics...... of the most recently described group, initially identified within the porcine teschovirus-1 RNA, which has strong similarities to the IRES elements from within the genomes of hepatitis C virus and the pestiviruses which are members of the flavivirus family. The selection of the initiation codon...

  4. New functionalities in abundant element oxides: ubiquitous element strategy.

    Science.gov (United States)

    Hosono, Hideo; Hayashi, Katsuro; Kamiya, Toshio; Atou, Toshiyuki; Susaki, Tomofumi

    2011-06-01

    While most ceramics are composed of ubiquitous elements (the ten most abundant elements within the Earth's crust), many advanced materials are based on rare elements. A 'rare-element crisis' is approaching owing to the imbalance between the limited supply of rare elements and the increasing demand. Therefore, we propose a 'ubiquitous element strategy' for materials research, which aims to apply abundant elements in a variety of innovative applications. Creation of innovative oxide materials and devices based on conventional ceramics is one specific challenge. This review describes the concept of ubiquitous element strategy and gives some highlights of our recent research on the synthesis of electronic, thermionic and structural materials using ubiquitous elements.

  5. Structural elements design manual

    CERN Document Server

    Draycott, Trevor

    2012-01-01

    Gives clear explanations of the logical design sequence for structural elements. The Structural Engineer says: `The book explains, in simple terms, and with many examples, Code of Practice methods for sizing structural sections in timber, concrete,masonry and steel. It is the combination into one book of section sizing methods in each of these materials that makes this text so useful....Students will find this an essential support text to the Codes of Practice in their study of element sizing'.

  6. New roof element system

    DEFF Research Database (Denmark)

    Ditlev, Jesper; Rudbeck, Claus Christian

    1997-01-01

    The aim of the project has been to develop an element system for warm deck roofs which, from a thermal and economical point of view, can deal with the future demands for heat loss coefficients for low slope roofs.......The aim of the project has been to develop an element system for warm deck roofs which, from a thermal and economical point of view, can deal with the future demands for heat loss coefficients for low slope roofs....

  7. Novel porcine repetitive elements

    Directory of Open Access Journals (Sweden)

    Nonneman Dan J

    2006-12-01

    Full Text Available Abstract Background Repetitive elements comprise ~45% of mammalian genomes and are increasingly known to impact genomic function by contributing to the genomic architecture, by direct regulation of gene expression and by affecting genomic size, diversity and evolution. The ubiquity and increasingly understood importance of repetitive elements contribute to the need to identify and annotate them. We set out to identify previously uncharacterized repetitive DNA in the porcine genome. Once found, we characterized the prevalence of these repeats in other mammals. Results We discovered 27 repetitive elements in 220 BACs covering 1% of the porcine genome (Comparative Vertebrate Sequencing Initiative; CVSI. These repeats varied in length from 55 to 1059 nucleotides. To estimate copy numbers, we went to an independent source of data, the BAC-end sequences (Wellcome Trust Sanger Institute, covering approximately 15% of the porcine genome. Copy numbers in BAC-ends were less than one hundred for 6 repeat elements, between 100 and 1000 for 16 and between 1,000 and 10,000 for 5. Several of the repeat elements were found in the bovine genome and we have identified two with orthologous sites, indicating that these elements were present in their common ancestor. None of the repeat elements were found in primate, rodent or dog genomes. We were unable to identify any of the replication machinery common to active transposable elements in these newly identified repeats. Conclusion The presence of both orthologous and non-orthologous sites indicates that some sites existed prior to speciation and some were generated later. The identification of low to moderate copy number repetitive DNA that is specific to artiodactyls will be critical in the assembly of livestock genomes and studies of comparative genomics.

  8. Atoms, molecules & elements

    CERN Document Server

    Graybill, George

    2007-01-01

    Young scientists will be thrilled to explore the invisible world of atoms, molecules and elements. Our resource provides ready-to-use information and activities for remedial students using simplified language and vocabulary. Students will label each part of the atom, learn what compounds are, and explore the patterns in the periodic table of elements to find calcium (Ca), chlorine (Cl), and helium (He) through hands-on activities.

  9. Nuclear fuel element

    Science.gov (United States)

    Zocher, Roy W.

    1991-01-01

    A nuclear fuel element and a method of manufacturing the element. The fuel element is comprised of a metal primary container and a fuel pellet which is located inside it and which is often fragmented. The primary container is subjected to elevated pressure and temperature to deform the container such that the container conforms to the fuel pellet, that is, such that the container is in substantial contact with the surface of the pellet. This conformance eliminates clearances which permit rubbing together of fuel pellet fragments and rubbing of fuel pellet fragments against the container, thus reducing the amount of dust inside the fuel container and the amount of dust which may escape in the event of container breach. Also, as a result of the inventive method, fuel pellet fragments tend to adhere to one another to form a coherent non-fragmented mass; this reduces the tendency of a fragment to pierce the container in the event of impact.

  10. Transposable elements in Drosophila

    Science.gov (United States)

    McCullers, Tabitha J.; Steiniger, Mindy

    2017-01-01

    ABSTRACT Transposable elements (TEs) are mobile genetic elements that can mobilize within host genomes. As TEs comprise more than 40% of the human genome and are linked to numerous diseases, understanding their mechanisms of mobilization and regulation is important. Drosophila melanogaster is an ideal model organism for the study of eukaryotic TEs as its genome contains a diverse array of active TEs. TEs universally impact host genome size via transposition and deletion events, but may also adopt unique functional roles in host organisms. There are 2 main classes of TEs: DNA transposons and retrotransposons. These classes are further divided into subgroups of TEs with unique structural and functional characteristics, demonstrating the significant variability among these elements. Despite this variability, D. melanogaster and other eukaryotic organisms utilize conserved mechanisms to regulate TEs. This review focuses on the transposition mechanisms and regulatory pathways of TEs, and their functional roles in D. melanogaster. PMID:28580197

  11. Advanced finite element technologies

    CERN Document Server

    Wriggers, Peter

    2016-01-01

    The book presents an overview of the state of research of advanced finite element technologies. Besides the mathematical analysis, the finite element development and their engineering applications are shown to the reader. The authors give a survey of the methods and technologies concerning efficiency, robustness and performance aspects. The book covers the topics of mathematical foundations for variational approaches and the mathematical understanding of the analytical requirements of modern finite element methods. Special attention is paid to finite deformations, adaptive strategies, incompressible, isotropic or anisotropic material behavior and the mathematical and numerical treatment of the well-known locking phenomenon. Beyond that new results for the introduced approaches are presented especially for challenging nonlinear problems.

  12. Fuel Element Technical Manual

    Energy Technology Data Exchange (ETDEWEB)

    Burley, H.H. [ed.

    1956-08-01

    It is the purpose of the Fuel Element Technical Manual to Provide a single document describing the fabrication processes used in the manufacture of the fuel element as well as the technical bases for these processes. The manual will be instrumental in the indoctrination of personnel new to the field and will provide a single data reference for all personnel involved in the design or manufacture of the fuel element. The material contained in this manual was assembled by members of the Engineering Department and the Manufacturing Department at the Hanford Atomic Products Operation between the dates October, 1955 and June, 1956. Arrangement of the manual. The manual is divided into six parts: Part I--introduction; Part II--technical bases; Part III--process; Part IV--plant and equipment; Part V--process control and improvement; and VI--safety.

  13. Intelligent Elements for ISHM

    Science.gov (United States)

    Schmalzel, John L.; Morris, Jon; Turowski, Mark; Figueroa, Fernando; Oostdyk, Rebecca

    2008-01-01

    There are a number of architecture models for implementing Integrated Systems Health Management (ISHM) capabilities. For example, approaches based on the OSA-CBM and OSA-EAI models, or specific architectures developed in response to local needs. NASA s John C. Stennis Space Center (SSC) has developed one such version of an extensible architecture in support of rocket engine testing that integrates a palette of functions in order to achieve an ISHM capability. Among the functional capabilities that are supported by the framework are: prognostic models, anomaly detection, a data base of supporting health information, root cause analysis, intelligent elements, and integrated awareness. This paper focuses on the role that intelligent elements can play in ISHM architectures. We define an intelligent element as a smart element with sufficient computing capacity to support anomaly detection or other algorithms in support of ISHM functions. A smart element has the capabilities of supporting networked implementations of IEEE 1451.x smart sensor and actuator protocols. The ISHM group at SSC has been actively developing intelligent elements in conjunction with several partners at other Centers, universities, and companies as part of our ISHM approach for better supporting rocket engine testing. We have developed several implementations. Among the key features for these intelligent sensors is support for IEEE 1451.1 and incorporation of a suite of algorithms for determination of sensor health. Regardless of the potential advantages that can be achieved using intelligent sensors, existing large-scale systems are still based on conventional sensors and data acquisition systems. In order to bring the benefits of intelligent sensors to these environments, we have also developed virtual implementations of intelligent sensors.

  14. Finite elements and approximation

    CERN Document Server

    Zienkiewicz, O C

    2006-01-01

    A powerful tool for the approximate solution of differential equations, the finite element is extensively used in industry and research. This book offers students of engineering and physics a comprehensive view of the principles involved, with numerous illustrative examples and exercises.Starting with continuum boundary value problems and the need for numerical discretization, the text examines finite difference methods, weighted residual methods in the context of continuous trial functions, and piecewise defined trial functions and the finite element method. Additional topics include higher o

  15. Rocket propulsion elements

    CERN Document Server

    Sutton, George P

    2011-01-01

    The definitive text on rocket propulsion-now revised to reflect advancements in the field For sixty years, Sutton's Rocket Propulsion Elements has been regarded as the single most authoritative sourcebook on rocket propulsion technology. As with the previous edition, coauthored with Oscar Biblarz, the Eighth Edition of Rocket Propulsion Elements offers a thorough introduction to basic principles of rocket propulsion for guided missiles, space flight, or satellite flight. It describes the physical mechanisms and designs for various types of rockets' and provides an unders

  16. Finite element analysis

    CERN Document Server

    2010-01-01

    Finite element analysis is an engineering method for the numerical analysis of complex structures. This book provides a bird's eye view on this very broad matter through 27 original and innovative research studies exhibiting various investigation directions. Through its chapters the reader will have access to works related to Biomedical Engineering, Materials Engineering, Process Analysis and Civil Engineering. The text is addressed not only to researchers, but also to professional engineers, engineering lecturers and students seeking to gain a better understanding of where Finite Element Analysis stands today.

  17. Elements of linear space

    CERN Document Server

    Amir-Moez, A R; Sneddon, I N

    1962-01-01

    Elements of Linear Space is a detailed treatment of the elements of linear spaces, including real spaces with no more than three dimensions and complex n-dimensional spaces. The geometry of conic sections and quadric surfaces is considered, along with algebraic structures, especially vector spaces and transformations. Problems drawn from various branches of geometry are given.Comprised of 12 chapters, this volume begins with an introduction to real Euclidean space, followed by a discussion on linear transformations and matrices. The addition and multiplication of transformations and matrices a

  18. Elements of social security

    DEFF Research Database (Denmark)

    Hansen, Hans

    (Alte Länder). This is the 9th and last edition of the publication,covering income levels and rules for social security and personal taxation for 1999. Basis for the projections to 1999 income levels is the 1998 data (in some cases 1999 data)for OECD's Taxing Wages as reported by national experts.......Elements of Social Security is a comparative study of important elements of the social security systems in Denmark (DK), Sweden (S), Finland (FIN), Austria (A), Germany (D), the Netherlands (NL), Great Britain (GB) and Canada (CAN). It should be emphasized that Germany is the former West Germany...

  19. New quasi-exactly solvable Hermitian as well as non-Hermitian PT ...

    Indian Academy of Sciences (India)

    Author Affiliations. Avinash Khare1 Bhabani Prasad Mandal2. Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005, India; Department of Physics, Banaras Hindu University, Varanasi 221 005, India ...

  20. New quasi-exactly solvable Hermitian as well as non-Hermitian PT ...

    Indian Academy of Sciences (India)

    B. = E + a2 − 12l − 21. 4a. ,. E = 8l + 15 − a2 ±. √. (2l + 3)2 − 4a2. (9). Note that since α = β the PT symmetry is unbroken and hence, as expected, the energy eigenvalues are real. Case ii. α = β = −l. The solutions in this case can be obtained from the solutions of Case i by everywhere changing l → −l − 1. Thus in this case, ...

  1. Photovoltaic radiation detector element

    Science.gov (United States)

    Agouridis, D.C.

    1980-12-17

    A radiation detector element is formed of a body of semiconductor material, a coating on the body which forms a photovoltaic junction therewith, and a current collector consisting of narrow metallic strips, the aforesaid coating having an opening therein in the edge of which closely approaches but is spaced from the current collector strips.

  2. Elements of Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 17; Issue 1. Elements of Chemistry. Antoine-Laurent Lavoisier. Classics Volume 17 Issue 1 January 2012 pp 92-100. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/017/01/0092-0100. Author Affiliations.

  3. Water, the intangible element

    NARCIS (Netherlands)

    Schotting, R.J.

    2009-01-01

    Water is the key to life. No living creature can survive without water. Too much water or polluted water are serious threats to mankind. Managing this intangible element is complex, not only in wet deltaic regions but also in the (semi-)arid regions of the world. Combined efforts of the

  4. JACKETED REACTOR FUEL ELEMENT

    Science.gov (United States)

    Smith, K.F.; Van Thyne, R.J.

    1958-12-01

    A fuel element is described for fast reactors comprised of a core of uranium metal containing material and a jacket around the core, the jacket consisting of from 2.5 to 15 percent of titanium, from 1 to 5 percent of niobium, and from 80 to 96.5 percent of vanadium.

  5. Elements of Social Security

    DEFF Research Database (Denmark)

    Hansen, Hans

    Elements of Social Security contains an overview of important benefit schemes in Denmark, Sweden, Finland, Germany, the Netherlands, Great Britain and Canada. The schemes are categorized according to common sets of criteria and compared. Stylized cases illustrate the impact on disposable income...

  6. Elements of Social Security

    DEFF Research Database (Denmark)

    Hansen, Hans

    Elements of Social Security contains an overview of important benefit schemes in Denmark, Sweden, Finland, Germany, Great Britain, the Netherlands and Canada. The schemes are categorized according to common sets of criteria and compared. Stylized cases illustrate the impact on disposable income...

  7. Elements of Social Security

    DEFF Research Database (Denmark)

    Hansen, Hans

    Elements of Social Security contains an overview of important benefit schemes in Denmark, Sweden, Finland, Austria, Germany, the Netherlands, Great Britain and Canada. The schemes are categorized according to common sets of criteria and compared. Stylized cases illustrate the impact on disposable...

  8. Inside finite elements

    CERN Document Server

    Weiser, Martin

    2016-01-01

    All relevant implementation aspects of finite element methods are discussed in this book. The focus is on algorithms and data structures as well as on their concrete implementation. Theory is covered as far as it gives insight into the construction of algorithms. Throughout the exercises a complete FE-solver for scalar 2D problems will be implemented in Matlab/Octave.

  9. CEDS Addresses: Rubric Elements

    Science.gov (United States)

    US Department of Education, 2015

    2015-01-01

    Common Education Data Standards (CEDS) Version 4 introduced a common data vocabulary for defining rubrics in a data system. The CEDS elements support digital representations of both holistic and analytic rubrics. This document shares examples of holistic and analytic project rubrics, available CEDS Connections, and a logical model showing the…

  10. Senescence responsive transcriptional element

    Science.gov (United States)

    Campisi, Judith; Testori, Alessandro

    1999-01-01

    Recombinant polynucleotides have expression control sequences that have a senescence responsive element and a minimal promoter, and which are operatively linked to a heterologous nucleotide sequence. The molecules are useful for achieving high levels of expression of genes in senescent cells. Methods of inhibiting expression of genes in senescent cells also are provided.

  11. Beam transport elements

    CERN Multimedia

    CERN PhotoLab

    1965-01-01

    Two of the beam transport elements for the slow ejection system. On the left, a quadrupole 1.2 m long with a 5 cm aperture, capable of producing a gradient of 5000 gauss. On the right, a 1 m bending magnet with a 4 cm gap; its field is 20 000 gauss.

  12. Epidemiology and trace elements.

    Science.gov (United States)

    Elwood, P C

    1985-08-01

    Basically, epidemiology is the making of measurements of known reproducibility, in a bias-free manner, on representative samples of subjects drawn from defined communities. Epidemiology has become a relatively precise science and its value in medicine is widely appreciated. So too are its limitations: the difficulties in achieving a high response rate, in identifying and controlling confounding factors in the examination of an association, and the ultimate difficulties in distinguishing causation from association. While the value of community-based studies seems to be recognized by those interested in man and his environment, the need for the strict application of epidemiological procedures, and the limitations imposed on conclusions drawn from studies in which these procedures have been compromised, does not seem to be adequately understood. There are certain known links between trace elements in the environment and disease: for example the level of iodine in soil and water and the prevalence of goitre; the level of fluoride in water and the prevalence of dental caries. The investigation of other possible associations is difficult for a number of reasons, including interrelationships between trace elements, confounding of trace element levels (and disease) with social and dietary factors, and the probability that relationships are generally weak. Two conditions in which associations are likely are cardiovascular disease and cancer. Despite research along a number of lines, the relevance of trace elements to cardiovascular disease is not clear, and certainly the apparent association with hardness of domestic water supply seems unlikely to be causal. The same general conclusion seems reasonable for cancer, and although there are a very few well established associations which are likely to be causal, such as exposure to arsenic and skin cancer, the role of trace elements is obscure, and likely to be very small.

  13. Element-topology-independent preconditioners for parallel finite element computations

    Science.gov (United States)

    Park, K. C.; Alexander, Scott

    1992-01-01

    A family of preconditioners for the solution of finite element equations are presented, which are element-topology independent and thus can be applicable to element order-free parallel computations. A key feature of the present preconditioners is the repeated use of element connectivity matrices and their left and right inverses. The properties and performance of the present preconditioners are demonstrated via beam and two-dimensional finite element matrices for implicit time integration computations.

  14. Elements of quantum optics

    CERN Document Server

    Meystre, Pierre

    2007-01-01

    Elements of Quantum Optics gives a self-contained and broad coverage of the basic elements necessary to understand and carry out research in laser physics and quantum optics, including a review of basic quantum mechanics and pedagogical introductions to system-reservoir interactions and to second quantization. The text reveals the close connection between many seemingly unrelated topics, such as probe absorption, four-wave mixing, optical instabilities, resonance fluorescence and squeezing. It also comprises discussions of cavity quantum electrodynamics and atom optics. The 4th edition includes a new chapter on quantum entanglement and quantum information, as well as added discussions of the quantum beam splitter, electromagnetically induced transparency, slow light, and the input-output formalism needed to understand many problems in quantum optics. It also provides an expanded treatment of the minimum-coupling Hamiltonian and a simple derivation of the Gross-Pitaevskii equation, an important gateway to rese...

  15. Archaeal extrachromosomal genetic elements

    DEFF Research Database (Denmark)

    Wang, Haina; Peng, Nan; Shah, Shiraz Ali

    2015-01-01

    SUMMARY: Research on archaeal extrachromosomal genetic elements (ECEs) has progressed rapidly in the past decade. To date, over 60 archaeal viruses and 60 plasmids have been isolated. These archaeal viruses exhibit an exceptional diversity in morphology, with a wide array of shapes, such as spind......SUMMARY: Research on archaeal extrachromosomal genetic elements (ECEs) has progressed rapidly in the past decade. To date, over 60 archaeal viruses and 60 plasmids have been isolated. These archaeal viruses exhibit an exceptional diversity in morphology, with a wide array of shapes...... on archaeal ECEs has just started to unravel the molecular biology of these genetic entities and their interactions with archaeal hosts, it is expected to accelerate in the next decade....

  16. Quantum theory elements

    CERN Document Server

    1962-01-01

    Quantum Theory: A Treatise in Three Volumes, I: Elements focuses on the principles, methodologies, and approaches involved in quantum theory, including quantum mechanics, linear combinations, collisions, and transitions. The selection first elaborates on the fundamental principles of quantum mechanics, exactly soluble bound state problems, and continuum. Discussions focus on delta function normalization, spherically symmetric potentials, rectangular potential wells, harmonic oscillators, spherically symmetrical potentials, Coulomb potential, axiomatic basis, consequences of first three postula

  17. Helium the disappearing element

    CERN Document Server

    Sears, Wheeler M

    2015-01-01

    The subject of the book is helium, the element, and its use in myriad applications including MRI machines, particle accelerators, space telescopes, and of course balloons and blimps. It was at the birth of our Universe, or the Big Bang, where the majority of cosmic helium was created; and stellar helium production continues. Although helium is the second most abundant element in the Universe, it is actually quite rare here on Earth and only exists because of radioactive elements deep within the Earth. This book includes a detailed history of the discovery of helium, of the commercial industry built around it, how the helium we actually encounter is produced within the Earth, and the state of the helium industry today. The gas that most people associate with birthday party balloons is running out. “Who cares?” you might ask. Well, without helium, MRI machines could not function, rockets could not go into space, particle accelerators such as those used by CERN could not operate, fiber optic cables would not...

  18. Chemical Elements Bingo

    Science.gov (United States)

    Tejeda, Silvia; Palacios, Joaquin

    1995-12-01

    An important part of the high school chemistry program is the topic of periodic classification and periodicity. We have observed that one of the obstacles for the study of the matter is the new vocabulary necessary to initiate this work. Our students have to understand that the periodic classification is an orderly way of presenting the elements and its properties, they compare the table with other classification systems that they already know, nevertheless for the average student it is difficult to deduce or predict properties with periodic classification. As an example of this concept, we can point out the electronic configuration, atomic radii, oxidation state, and valence number. In order to facilitate the learning-teaching process of this topic in high school level, we stimulate the class to play with the periodic table, to get familiar with the general concepts of periodicity. We started our work dealing with the most common elements in each group. Chemical Elements Bingo (CEB) is a game we designed to teach periodic classification.

  19. New functionalities in abundant element oxides: ubiquitous element strategy

    Directory of Open Access Journals (Sweden)

    Hideo Hosono, Katsuro Hayashi, Toshio Kamiya, Toshiyuki Atou and Tomofumi Susaki

    2011-01-01

    Full Text Available While most ceramics are composed of ubiquitous elements (the ten most abundant elements within the Earth's crust, many advanced materials are based on rare elements. A 'rare-element crisis' is approaching owing to the imbalance between the limited supply of rare elements and the increasing demand. Therefore, we propose a 'ubiquitous element strategy' for materials research, which aims to apply abundant elements in a variety of innovative applications. Creation of innovative oxide materials and devices based on conventional ceramics is one specific challenge. This review describes the concept of ubiquitous element strategy and gives some highlights of our recent research on the synthesis of electronic, thermionic and structural materials using ubiquitous elements.

  20. Elemental matrices for the finite element method in electromagnetics with quadratic triangular elements

    OpenAIRE

    Cojocaru, E.

    2009-01-01

    The finite element method has become a preeminent simulation technique in electromagnetics. For problems involving anisotropic media and metamaterials, proper algorithms should be developed. It has been proved that discretizing in quadratic triangular elements may lead to an improved accuracy. Here we present a collection of elemental matrices evaluated analytically for quadratic triangular elements. They could be useful for the finite element method in advanced electromagnetics.

  1. Elements of social action

    Directory of Open Access Journals (Sweden)

    Marjanović Miloš

    2011-01-01

    Full Text Available Because of the significant analytical advantages, the author prefers social action as initial sociological concept in the relation to social phenomenon. Its basic elements are: actors, subjects and tools, needs and interests, values and norms, positions and roles. Actors set in motion and unify the rest of elements, guide to the magic triangle of sociology (movement, change, order, reaffirm actor paradigm to systemic paradigm. Subjects and tools materialize an action and its overestimate results in technological determinism or (by means of property as institutional appropriation of nature in the (unclassed historical type of society. Needs and interests are the basis of person's motivation and starting point for depth analysis of sociability. The expansion of legitimate interests circle develops techniques of normative regulation. Values and norms guide to institutional-organizational, positions to vertical and roles to horizontal structure. Values give the meaning to the action as well as to human existence, they are orientations of motivate system of personality but also basic aspect of society. As abstractions, values are latent background of norms and they tell to us what to do, and norms how to do something. Norms are specified instructions for suitable behavior Without normative order, not to be possible the satisfying of needs and the conciliation of interests. Riches, power and prestige are components of social position, and legal status is the determination of rights and obligations of the position. Roles are normative expectation of behavior. Toward kinds of sanctions roles are classified. Roles but also other elements of social action are starting point for sociological analysis of legal norms and institutes. On the other side, the observation of legal component of social actions enriches, strengths and precises sociological analysis of them.

  2. Elements of analytical dynamics

    CERN Document Server

    Kurth, Rudolph; Stark, M

    1976-01-01

    Elements of Analytical Dynamics deals with dynamics, which studies the relationship between motion of material bodies and the forces acting on them. This book is a compilation of lectures given by the author at the Georgia and Institute of Technology and formed a part of a course in Topological Dynamics. The book begins by discussing the notions of space and time and their basic properties. It then discusses the Hamilton-Jacobi theory and Hamilton's principle and first integrals. The text concludes with a discussion on Jacobi's geometric interpretation of conservative systems. This book will

  3. Analytical elements of mechanics

    CERN Document Server

    Kane, Thomas R

    2013-01-01

    Analytical Elements of Mechanics, Volume 1, is the first of two volumes intended for use in courses in classical mechanics. The books aim to provide students and teachers with a text consistent in content and format with the author's ideas regarding the subject matter and teaching of mechanics, and to disseminate these ideas. The book opens with a detailed exposition of vector algebra, and no prior knowledge of this subject is required. This is followed by a chapter on the topic of mass centers, which is presented as a logical extension of concepts introduced in connection with centroids. A

  4. Osteoporosis and trace elements

    DEFF Research Database (Denmark)

    Aaseth, J.; Boivin, G.; Andersen, Ole

    2012-01-01

    More than 200 million people are affected by osteoporosis worldwide, as estimated by 2 million annual hip fractures and other debilitating bone fractures (vertebrae compression and Colles' fractures). Osteoporosis is a multi-factorial disease with potential contributions from genetic, endocrine...... in new bone and results in a net gain in bone mass, but may be associated with a tissue of poor quality. Aluminum induces impairment of bone formation. Gallium and cadmium suppresses bone turnover. However, exact involvements of the trace elements in osteoporosis have not yet been fully clarified...

  5. Elements of Architecture

    DEFF Research Database (Denmark)

    Elements of Architecture explores new ways of engaging architecture in archaeology. It conceives of architecture both as the physical evidence of past societies and as existing beyond the physical environment, considering how people in the past have not just dwelled in buildings but have existed...... and affective impacts, of these material remains. The contributions in this volume investigate the way time, performance and movement, both physically and emotionally, are central aspects of understanding architectural assemblages. It is a book about the constellations of people, places and things that emerge...

  6. Elements of energy conversion

    CERN Document Server

    Russell, Charles R

    2013-01-01

    Elements of Energy Conversion brings together scattered information on the subject of energy conversion and presents it in terms of the fundamental thermodynamics that apply to energy conversion by any process. Emphasis is given to the development of the theory of heat engines because these are and will remain most important power sources. Descriptive material is then presented to provide elementary information on all important energy conversion devices. The book contains 10 chapters and opens with a discussion of forms of energy, energy sources and storage, and energy conversion. This is foll

  7. [Healthcare marketing elements].

    Science.gov (United States)

    Ameri, Cinzia; Fiorini, Fulvio

    2014-01-01

    Marketing puts its foundation on a few key concepts: need-demand, product-service, satisfaction, exchange, market, or business structure manufacturing / supply. The combination of these elements allows you to build an effective marketing strategy. Crucial in this respect is to remember the Porter matrix, which shows that for a correct analysis of the relevant market is necessary to refer to the "five forces at play", ie: customers, competitors, new entrants and substitutes threat. Another key lever for proper marketing oriented approach is the continuous and constant monitoring of the application, anticipating their dissatisfactions.

  8. Ring-laser gyroscope system using dispersive element(s)

    Science.gov (United States)

    Smith, David D. (Inventor)

    2010-01-01

    A ring-laser gyroscope system includes a ring-laser gyroscope (RLG) and at least one dispersive element optically coupled to the RLG's ring-shaped optical path. Each dispersive element has a resonant frequency that is approximately equal to the RLG's lasing frequency. A group index of refraction defined collectively by the dispersive element(s) has (i) a real portion that is greater than zero and less than one, and (ii) an imaginary portion that is less than zero.

  9. Heavy element nucleosynthesis

    CERN Document Server

    Schramm, D N

    1976-01-01

    A review is made of current nuclear astrophysical theory regarding the origin of the elements heavier than iron. The pre-supernova evolution of stars is very briefly described, and speculation is given regarding the supernova mechanism. In particular, the possible role of weak neutral currents is presented. The synthesis of the trans-iron nuclei via the s and r-processes is examined. Special emphasis is given to the r-process because it depends completely on the properties of nuclei off the valley of stability. Recent explosive r-process calculations are discussed, as well as plausible astrophysical sites. The alternative n-process is also described. The possible production by the r and/or n-processes of the almost mythical superheavy elements is reviewed. The sensitivity of the results to certain crudely estimated parameters is explicitly shown. Throughout the discussion, the importance of certain nuclear physics experiments and formalism is demonstrated. Areas where advances in nuclear physics will have a d...

  10. The CEBAF Element Database

    Energy Technology Data Exchange (ETDEWEB)

    Theodore Larrieu, Christopher Slominski, Michele Joyce

    2011-03-01

    With the inauguration of the CEBAF Element Database (CED) in Fall 2010, Jefferson Lab computer scientists have taken a step toward the eventual goal of a model-driven accelerator. Once fully populated, the database will be the primary repository of information used for everything from generating lattice decks to booting control computers to building controls screens. A requirement influencing the CED design is that it provide access to not only present, but also future and past configurations of the accelerator. To accomplish this, an introspective database schema was designed that allows new elements, types, and properties to be defined on-the-fly with no changes to table structure. Used in conjunction with Oracle Workspace Manager, it allows users to query data from any time in the database history with the same tools used to query the present configuration. Users can also check-out workspaces to use as staging areas for upcoming machine configurations. All Access to the CED is through a well-documented Application Programming Interface (API) that is translated automatically from original C++ source code into native libraries for scripting languages such as perl, php, and TCL making access to the CED easy and ubiquitous.

  11. NIH Common Data Elements Repository

    Data.gov (United States)

    U.S. Department of Health & Human Services — The NIH Common Data Elements (CDE) Repository has been designed to provide access to structured human and machine-readable definitions of data elements that have...

  12. Trace element emissions from coal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-09-15

    Trace elements are emitted during coal combustion. The quantity, in general, depends on the physical and chemical properties of the element itself, the concentration of the element in the coal, the combustion conditions and the type of particulate control device used, and its collection efficiency as a function of particle size. Some trace elements become concentrated in certain particle streams following combustion such as bottom ash, fly ash, and flue gas particulate matter, while others do not. Various classification schemes have been developed to describe this partitioning behaviour. These classification schemes generally distinguish between: Class 1: elements that are approximately equally concentrated in the fly ash and bottom ash, or show little or no fine particle enrichment, examples include Mn, Be, Co and Cr; Class 2: elements that are enriched in the fly ash relative to bottom ash, or show increasing enrichment with decreasing particle size, examples include As, Cd, Pb and Sb; Class 3: elements which are emitted in the gas phase (primarily Hg (not discussed in this review), and in some cases, Se). Control of class 1 trace elements is directly related to control of total particulate matter emissions, while control of the class 2 elements depends on collection of fine particulates. Due to the variability in particulate control device efficiencies, emission rates of these elements can vary substantially. The volatility of class 3 elements means that particulate controls have only a limited impact on the emissions of these elements.

  13. REACTOR FUEL ELEMENTS TESTING CONTAINER

    Science.gov (United States)

    Whitham, G.K.; Smith, R.R.

    1963-01-15

    This patent shows a method for detecting leaks in jacketed fuel elements. The element is placed in a sealed tank within a nuclear reactor, and, while the reactor operates, the element is sparged with gas. The gas is then led outside the reactor and monitored for radioactive Xe or Kr. (AEC)

  14. The nonconforming virtual element method

    OpenAIRE

    de Dios, B. Ayuso; Lipnikov, K.; Manzini, G

    2014-01-01

    We introduce the nonconforming Virtual Element Method (VEM) for the approximation of second order elliptic problems. We present the construction of the new element in two and three dimensions, highlighting the main differences with the conforming VEM and the classical nonconforming finite element methods. We provide the error analysis and establish the equivalence with a family of mimetic finite difference methods.

  15. It is elemental

    DEFF Research Database (Denmark)

    Delgado-Baquerizo, Manuel; Reich, Peter B.; Khachane, Amit N.

    2017-01-01

    diversity and composition were primarily driven by variation in soil resource stoichiometry (total C:N:P ratios), itself linked to different land uses, and secondarily driven by other important biodiversity drivers such as climate, soil spatial heterogeneity, soil pH, root influence (plant-soil microbe......It is well established that resource quantity and elemental stoichiometry play major roles in shaping below and aboveground plant biodiversity, but their importance for shaping microbial diversity in soil remains unclear. Here, we used statistical modeling on a regional database covering 179...... interactions) and microbial biomass (soil microbe-microbe interactions). In aggregate, these findings provide evidence that nutrient stoichiometry is a strong predictor of bacterial diversity and composition at a regional scale. This article is protected by copyright. All rights reserved....

  16. Ucla, escuela elemental

    Directory of Open Access Journals (Sweden)

    Neutra, Richard J.

    1962-03-01

    Full Text Available La Escuela Elemental de Preparación de la Universidad de California, en Los Angeles, está dedicada a la educación e investigación y preparación del profesorado de la infancia. Se ha construido en un paraje maravilloso, de frondosa vegetación, frente a un terreno bastante quebrado, circunstancia que presta mayor encanto al conjunto, construido con gran pericia y adaptación al paisaje a base de una dominante horizontalidad, con materiales sencillos (ladrillos, hierro y madera y gran comunicación con la naturaleza mediante grandes cristaleras correderas que ensanchan las clases y las suplementan hacia el jardín de acuerdo con las nuevas normas y prácticas docentes.

  17. Solar cell element

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Satoru; Matsukuma, Kunihiro; Kokuuchi, Shigeru; Morita, Keiichi; Yagi, Hideyuki.

    1989-07-17

    This invention aims to provide a soalr cell element with an easily formable electrode having an independent BSF and BSR. For this purpose, in this invention, a layer with high concentration of impurities (which functions as BSF on the opposite surface of the light-receiving surface) is partly and adjacently placed; a back electrode is made to have an ohmic resistance to the high-impurity layer; a metal oxide film is forther placed in other parts. By this, the functions of BSF and BSR are sufficiently utilized as a boundary surface between the high-impurity layer (BSF) and the semi-conductor substrate and the metal oxide film (BSR) are separated, thus enhancing the conversion efficiency. As for the patterns on the separated layers of BSF and BSR, various patterns are possible to be relized by using resist printing patterns. 3 figs.

  18. ELEMENTAL FORMS OF HOSPITALITY

    Directory of Open Access Journals (Sweden)

    Maximiliano Emanuel Korstanje

    2010-11-01

    Full Text Available Modern studies emphasized on the needs of researching the hospitality as relevant aspects of tourism and hospitality fields. Anyway, these approaches are inextricably intertwined to the industry of tourism and do not take seriously the anthropological and sociological roots of hospitality. In fact, the hotel seems to be a partial sphere of hospitality at all. Under this context, the present paper explores the issue of hospitality enrooted in the political and economic indo-European principle of free-transit which is associated to a much broader origin.  Starting from the premise etymologically hostel and hospital share similar origins, we follow the contributions of J Derrida to determine the elements that formed the hospitality up to date.

  19. The fantastic four.. elements

    Science.gov (United States)

    Marsili, Antonella; D'Addezio, Giuliana; Rubbia, Giuliana; Ramieri, Caterina; Todaro, Riccardo; Scipilliti, Francesca; Tosto, Eleonora

    2015-04-01

    With a "Sunday between territory and music to 'National Institute of Geophysics and Volcanology," October 12, 2014 the headquarters of INGV Roma kicked off the activities of the second edition of the Week of Planet Earth. The laboratory of scientific outreach and museum activities together with volunteers of the National Civil Service have organized the whole day dedicated to the dissemination of earth sciences, involving adults and children. Especially for primary school children a laboratory was made involving three amusing activities all aimed at inspiring respect for the Earth: a theatrical representation called "The Fantastic 4... elements", a behavioral game and a nursery rhyme reading. The theater as a means of communication of science is an innovative and creative way to introduce children to important scientific concepts. The use of this methodology and simple language favoring the emotional involvement of the child facilitating learning. The main character is a child, chosen to facilitate the identification of the spectators with the protagonist, that through a fantastic journey discovers the importance of the four elements of our planet: earth, fire, air and water. As a second step, volunteers involved children in reading a nursery rhyme "the ABC to become a Friend of the Earth" inviting them to protect and respect the environment and its resources. Finally, the behavioral game gave indications about behaviors to adopt to safeguard the planet. Volunteers introduced a billboard divided into two colors, green to indicate the right behaviors and red for the wrong ones. Each child, after reading a card with indication on the behavior to adopt, had to decide if they were correct or not with respect to the environment safeguard. After listening to the children's answer, the volunteer gave the correct explanation about the appropriate behavior to adopt. At the end of the activities, each child received a certificate as "a friend of Planet Earth".

  20. The Chemistry of Superheavy Elements

    CERN Document Server

    Schädel, M

    2003-01-01

    The chemistry of transactinide or superheavy elements has reached element 108. Preparations are under way to leap to element 112 and beyond. The current status of this atom-at-a-time chemical research and its future perspectives are reviewed from an experimental point of view together with some of the interesting results from n -rich nuclides near and at the N=162 neutron shell. Experimental techniques and important results enlightening typical chemical properties of elements 104 through 108 are presented in an exemplary way. From the results of these experiments it is justified to place these elements in the Periodic Table of the Elements in to groups 4 through 8, respectively. However, mainly due to the influence of relativistic effects, it is no longer possible to deduce detailed chemical properties of these superheavy elements simply from this position.

  1. Chemical characterization of element 112.

    Science.gov (United States)

    Eichler, R; Aksenov, N V; Belozerov, A V; Bozhikov, G A; Chepigin, V I; Dmitriev, S N; Dressler, R; Gäggeler, H W; Gorshkov, V A; Haenssler, F; Itkis, M G; Laube, A; Lebedev, V Ya; Malyshev, O N; Oganessian, Yu Ts; Petrushkin, O V; Piguet, D; Rasmussen, P; Shishkin, S V; Shutov, A V; Svirikhin, A I; Tereshatov, E E; Vostokin, G K; Wegrzecki, M; Yeremin, A V

    2007-05-03

    The heaviest elements to have been chemically characterized are seaborgium (element 106), bohrium (element 107) and hassium (element 108). All three behave according to their respective positions in groups 6, 7 and 8 of the periodic table, which arranges elements according to their outermost electrons and hence their chemical properties. However, the chemical characterization results are not trivial: relativistic effects on the electronic structure of the heaviest elements can strongly influence chemical properties. The next heavy element targeted for chemical characterization is element 112; its closed-shell electronic structure with a filled outer s orbital suggests that it may be particularly susceptible to strong deviations from the chemical property trends expected within group 12. Indeed, first experiments concluded that element 112 does not behave like its lighter homologue mercury. However, the production and identification methods used cast doubt on the validity of this result. Here we report a more reliable chemical characterization of element 112, involving the production of two atoms of (283)112 through the alpha decay of the short-lived (287)114 (which itself forms in the nuclear fusion reaction of 48Ca with 242Pu) and the adsorption of the two atoms on a gold surface. By directly comparing the adsorption characteristics of (283)112 to that of mercury and the noble gas radon, we find that element 112 is very volatile and, unlike radon, reveals a metallic interaction with the gold surface. These adsorption characteristics establish element 112 as a typical element of group 12, and its successful production unambiguously establishes the approach to the island of stability of superheavy elements through 48Ca-induced nuclear fusion reactions with actinides.

  2. Elements and elasmobranchs: hypotheses, assumptions and limitations of elemental analysis.

    Science.gov (United States)

    McMillan, M N; Izzo, C; Wade, B; Gillanders, B M

    2017-02-01

    Quantifying the elemental composition of elasmobranch calcified cartilage (hard parts) has the potential to answer a range of ecological and biological questions, at both the individual and population level. Few studies, however, have employed elemental analyses of elasmobranch hard parts. This paper provides an overview of the range of applications of elemental analysis in elasmobranchs, discussing the assumptions and potential limitations in cartilaginous fishes. It also reviews the available information on biotic and abiotic factors influencing patterns of elemental incorporation into hard parts of elasmobranchs and provides some comparative elemental assays and mapping in an attempt to fill knowledge gaps. Directions for future experimental research are highlighted to better understand fundamental elemental dynamics in elasmobranch hard parts. © 2016 The Fisheries Society of the British Isles.

  3. Vesta's Elemental Composition

    Science.gov (United States)

    Prettyman, T. H.; Beck, A. W.; Feldman, W. C.; Lawrence, D. J.; McCoy, T. J.; McSween, H. Y.; Mittlefehldt, D. W.; Peplowski, P. N.; Raymond, C. A.; Reedy, R. C.; hide

    2014-01-01

    Many lines of evidence (e.g. common geochemistry, chronology, O-isotope trends, and the presence of different HED rock types in polymict breccias) indicate that the howardite, eucrite, and diogenite (HED) meteorites originated from a single parent body. Meteorite studies show that this protoplanet underwent igneous differentiation to form a metallic core, an ultramafic mantle, and a basaltic crust. A spectroscopic match between the HEDs and 4 Vesta along with a plausible mechanism for their transfer to Earth, perhaps as chips off V-type asteroids ejected from Vesta's southern impact basin, supports the consensus view that many of these achondritic meteorites are samples of Vesta's crust and upper mantle. The HED-Vesta connection was put to the test by the NASA Dawn mission, which spent a year in close proximity to Vesta. Measurements by Dawn's three instruments, redundant Framing Cameras (FC), a Visible-InfraRed (VIR) spectrometer, and a Gamma Ray and Neutron Detector (GRaND), along with radio science have strengthened the link. Gravity measurements by Dawn are consistent with a differentiated, silicate body, with a dense Fe-rich core. The range of pyroxene compositions determined by VIR overlaps that of the howardites. Elemental abundances determined by nuclear spectroscopy are also consistent with HED-compositions. Observations by GRaND provided a new view of Vesta inaccessible by telescopic observations. Here, we summarize the results of Dawn's geochemical investigation of Vesta and their implications.

  4. Lubrication of Machine Elements

    Science.gov (United States)

    Hamrock, Bernard J.

    1984-01-01

    The understanding of hydrodynamic lubrication began with the classical experiments of Tower and Petrov. Reynolds used a reduced form of the Navier-Stokes equations and the continuity equation to generate a second order differential equation for the pressure in the narrow, converging gap of a bearing contact. Such a pressure enables a load to be transmitted between the surfaces with very low friction since the surfaces are completely separated by a film of fluid. In such a situation it is the physical properties of the lubricant, notably the dynamic viscosity, that dictate the behavior of the contact. The understanding of boundary lubrication is normally attributed to Hardy and Doubleday. In boundary lubrication it is the physical and chemical properties of thin films of molecular proportions and the surfaces to which they are attached that determine contact behavior. The lubricant viscosity is not an influential parameter. Research is devoted to a better understanding and more precise definition of other lubrication regimes between these extremes. One such regime, elastohydrodynamic lubrication, occurs in nonconformal contacts, where the pressures are high and the bearing surfaces deform elastically. In this situation the viscosity of the lubricant may raise considerably, and this further assists the formation of an effective fluid film. The science of these three lubrication regimes (hydrodynamic, elastohydrodynamic, and boundary) are described and the manner in which this science is used in the design of machine elements is examined.

  5. Chemistry of the superheavy elements.

    Science.gov (United States)

    Schädel, Matthias

    2015-03-13

    The quest for superheavy elements (SHEs) is driven by the desire to find and explore one of the extreme limits of existence of matter. These elements exist solely due to their nuclear shell stabilization. All 15 presently 'known' SHEs (11 are officially 'discovered' and named) up to element 118 are short-lived and are man-made atom-at-a-time in heavy ion induced nuclear reactions. They are identical to the transactinide elements located in the seventh period of the periodic table beginning with rutherfordium (element 104), dubnium (element 105) and seaborgium (element 106) in groups 4, 5 and 6, respectively. Their chemical properties are often surprising and unexpected from simple extrapolations. After hassium (element 108), chemistry has now reached copernicium (element 112) and flerovium (element 114). For the later ones, the focus is on questions of their metallic or possibly noble gas-like character originating from interplay of most pronounced relativistic effects and electron-shell effects. SHEs provide unique opportunities to get insights into the influence of strong relativistic effects on the atomic electrons and to probe 'relativistically' influenced chemical properties and the architecture of the periodic table at its farthest reach. In addition, they establish a test bench to challenge the validity and predictive power of modern fully relativistic quantum chemical models. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  6. Archaeal Extrachromosomal Genetic Elements

    Science.gov (United States)

    Wang, Haina; Peng, Nan; Shah, Shiraz A.

    2015-01-01

    SUMMARY Research on archaeal extrachromosomal genetic elements (ECEs) has progressed rapidly in the past decade. To date, over 60 archaeal viruses and 60 plasmids have been isolated. These archaeal viruses exhibit an exceptional diversity in morphology, with a wide array of shapes, such as spindles, rods, filaments, spheres, head-tails, bottles, and droplets, and some of these new viruses have been classified into one order, 10 families, and 16 genera. Investigation of model archaeal viruses has yielded important insights into mechanisms underlining various steps in the viral life cycle, including infection, DNA replication and transcription, and virion egression. Many of these mechanisms are unprecedented for any known bacterial or eukaryal viruses. Studies of plasmids isolated from different archaeal hosts have also revealed a striking diversity in gene content and innovation in replication strategies. Highly divergent replication proteins are identified in both viral and plasmid genomes. Genomic studies of archaeal ECEs have revealed a modular sequence structure in which modules of DNA sequence are exchangeable within, as well as among, plasmid families and probably also between viruses and plasmids. In particular, it has been suggested that ECE-host interactions have shaped the coevolution of ECEs and their archaeal hosts. Furthermore, archaeal hosts have developed defense systems, including the innate restriction-modification (R-M) system and the adaptive CRISPR (clustered regularly interspaced short palindromic repeats) system, to restrict invasive plasmids and viruses. Together, these interactions permit a delicate balance between ECEs and their hosts, which is vitally important for maintaining an innovative gene reservoir carried by ECEs. In conclusion, while research on archaeal ECEs has just started to unravel the molecular biology of these genetic entities and their interactions with archaeal hosts, it is expected to accelerate in the next decade. PMID

  7. Photoshop Elements 10 For Dummies

    CERN Document Server

    Obermeier, Barbara

    2011-01-01

    Perfect your photos and images with this "focused" guide to the latest version of Photoshop Elements For most of us, the professional-level Photoshop is overkill for our needs. Amateur photographers and photo enthusiasts turn to Photoshop Elements for a powerful but simpler way to edit and retouch their snapshots. Photoshop Elements 10 For Dummies, fully updated and revised for the latest release of this software product, helps you navigate Elements to create, edit, fix, share, and organize the high-quality images you desire. Full color pages bring the techniques to life and make taking great

  8. Rare-earth elements

    Science.gov (United States)

    Van Gosen, Bradley S.; Verplanck, Philip L.; Seal, Robert R.; Long, Keith R.; Gambogi, Joseph; Schulz, Klaus J.; DeYoung, John H.; Seal, Robert R.; Bradley, Dwight C.

    2017-12-19

    The rare-earth elements (REEs) are 15 elements that range in atomic number from 57 (lanthanum) to 71 (lutetium); they are commonly referred to as the “lanthanides.” Yttrium (atomic number 39) is also commonly regarded as an REE because it shares chemical and physical similarities and has affinities with the lanthanides. Although REEs are not rare in terms of average crustal abundance, the concentrated deposits of REEs are limited in number.Because of their unusual physical and chemical properties, the REEs have diverse defense, energy, industrial, and military technology applications. The glass industry is the leading consumer of REE raw materials, which are used for glass polishing and as additives that provide color and special optical properties to the glass. Lanthanum-based catalysts are used in petroleum refining, and cerium-based catalysts are used in automotive catalytic converters. The use of REEs in magnets is a rapidly increasing application. Neodymium-iron-boron magnets, which are the strongest known type of magnets, are used when space and weight are restrictions. Nickel-metal hydride batteries use anodes made of a lanthanum-based alloys.China, which has led the world production of REEs for decades, accounted for more than 90 percent of global production and supply, on average, during the past decade. Citing a need to retain its limited REE resources to meet domestic requirements as well as concerns about the environmental effects of mining, China began placing restrictions on the supply of REEs in 2010 through the imposition of quotas, licenses, and taxes. As a result, the global rare-earth industry has increased its stockpiling of REEs; explored for deposits outside of China; and promoted new efforts to conserve, recycle, and substitute for REEs. New mine production began at Mount Weld in Western Australia, and numerous other exploration and development projects noted in this chapter are ongoing throughout the world.The REE-bearing minerals are

  9. Trace Elements in River Waters

    Science.gov (United States)

    Gaillardet, J.; Viers, J.; Dupré, B.

    2003-12-01

    Trace elements are characterized by concentrations lower than 1 mg L-1 in natural waters. This means that trace elements are not considered when "total dissolved solids" are calculated in rivers, lakes, or groundwaters, because their combined mass is not significant compared to the sum of Na+, K+, Ca2+, Mg2+, H4SiO4, HCO3-, CO32-, SO42-, Cl-, and NO3-. Therefore, most of the elements, except about ten of them, occur at trace levels in natural waters. Being trace elements in natural waters does not necessarily qualify them as trace elements in rocks. For example, aluminum, iron, and titanium are major elements in rocks, but they occur as trace elements in waters, due to their low mobility at the Earth's surface. Conversely, trace elements in rocks such as chlorine and carbon are major elements in waters.The geochemistry of trace elements in river waters, like that of groundwater and seawater, is receiving increasing attention. This growing interest is clearly triggered by the technical advances made in the determination of concentrations at lower levels in water. In particular, the development of inductively coupled plasma mass spectrometry (ICP-MS) has considerably improved our knowledge of trace-element levels in waters since the early 1990s. ICP-MS provides the capability of determining trace elements having isotopes of interest for geochemical dating or tracing, even where their dissolved concentrations are extremely low.The determination of trace elements in natural waters is motivated by a number of issues. Although rare, trace elements in natural systems can play a major role in hydrosystems. This is particularly evident for toxic elements such as aluminum, whose concentrations are related to the abundance of fish in rivers. Many trace elements have been exploited from natural accumulation sites and used over thousands of years by human activities. Trace elements are therefore highly sensitive indexes of human impact from local to global scale. Pollution

  10. Clean elements in abelian rings

    Indian Academy of Sciences (India)

    Let be a ring with identity. An element in is said to be clean if it is the sum of a unit and an idempotent. is said to be clean if all of its elements are clean. If every idempotent in is central, then is said to be abelian. In this paper we obtain some conditions equivalent to being clean in an abelian ring.

  11. Lysets rytme som belysningsarkitektonisk element

    DEFF Research Database (Denmark)

    Bülow, Katja

    2009-01-01

    I den rytmiske tilgang til arkitektonisk belysning betragtes lyskilder som agerende elementer i et landskab, hvor en iagttager interagerer med lyset fra lyskilden.......I den rytmiske tilgang til arkitektonisk belysning betragtes lyskilder som agerende elementer i et landskab, hvor en iagttager interagerer med lyset fra lyskilden....

  12. Chemical experiments with superheavy elements.

    Science.gov (United States)

    Türler, Andreas

    2010-01-01

    Unnoticed by many chemists, the Periodic Table of the Elements has been extended significantly in the last couple of years and the 7th period has very recently been completed with eka-Rn (element 118) currently being the heaviest element whose synthesis has been reported. These 'superheavy' elements (also called transactinides with atomic number > or = 104 (Rf)) have been artificially synthesized in fusion reactions at accelerators in minute quantities of a few single atoms. In addition, all isotopes of the transactinide elements are radioactive and decay with rather short half-lives. Nevertheless, it has been possible in some cases to investigate experimentally chemical properties of transactinide elements and even synthesize simple compounds. The experimental investigation of superheavy elements is especially intriguing, since theoretical calculations predict significant deviations from periodic trends due to the influence of strong relativistic effects. In this contribution first experiments with hassium (Hs, atomic number 108), copernicium (Cn, atomic number 112) and element 114 (eka-Pb) are reviewed.

  13. Solution of Finite Element Equations

    DEFF Research Database (Denmark)

    Krenk, Steen

    An important step in solving any problem by the finite element method is the solution of the global equations. Numerical solution of linear equations is a subject covered in most courses in numerical analysis. However, the equations encountered in most finite element applications have some special...

  14. Repetitive elements in parasitic protozoa

    Directory of Open Access Journals (Sweden)

    Clayton Christine

    2010-05-01

    Full Text Available Abstract A recent paper published in BMC Genomics suggests that retrotransposition may be active in the human gut parasite Entamoeba histolytica. This adds to our knowledge of the various types of repetitive elements in parasitic protists and the potential influence of such elements on pathogenicity. See research article http://www.biomedcentral.com/1471-2164/11/321

  15. What Is a Chemical Element?

    Science.gov (United States)

    ten Hoor, Marten J.

    2017-01-01

    Contrary to current IUPAC recommendations, the chemical element X should be defined as the nucleus of the X atom. Consequently, different isotopes with their different nuclei belong to different elements, each one with its own physical and chemical properties. This view leads to the conclusion that we no longer have a periodic table of the…

  16. Massively Parallel Finite Element Programming

    KAUST Repository

    Heister, Timo

    2010-01-01

    Today\\'s large finite element simulations require parallel algorithms to scale on clusters with thousands or tens of thousands of processor cores. We present data structures and algorithms to take advantage of the power of high performance computers in generic finite element codes. Existing generic finite element libraries often restrict the parallelization to parallel linear algebra routines. This is a limiting factor when solving on more than a few hundreds of cores. We describe routines for distributed storage of all major components coupled with efficient, scalable algorithms. We give an overview of our effort to enable the modern and generic finite element library deal.II to take advantage of the power of large clusters. In particular, we describe the construction of a distributed mesh and develop algorithms to fully parallelize the finite element calculation. Numerical results demonstrate good scalability. © 2010 Springer-Verlag.

  17. Regulatory elements in molecular networks.

    Science.gov (United States)

    Doane, Ashley S; Elemento, Olivier

    2017-05-01

    Regulatory elements determine the connectivity of molecular networks and mediate a variety of regulatory processes ranging from DNA looping to transcriptional, posttranscriptional, and posttranslational regulation. This review highlights our current understanding of the different types of regulatory elements found in molecular networks with a focus on DNA regulatory elements. We highlight technical advances and current challenges for the mapping of regulatory elements at the genome-wide scale, and describe new computational methods to uncover these elements via reconstructing regulatory networks from large genomic datasets. WIREs Syst Biol Med 2017, 9:e1374. doi: 10.1002/wsbm.1374 For further resources related to this article, please visit the WIREs website. © 2017 Wiley Periodicals, Inc.

  18. Platinum-group elements

    Science.gov (United States)

    Zientek, Michael L.; Loferski, Patricia J.; Parks, Heather L.; Schulte, Ruth F.; Seal, Robert R.; Schulz, Klaus J.; DeYoung, John H.; Seal, Robert R.; Bradley, Dwight C.

    2017-12-19

    The platinum-group elements (PGEs)—platinum, palladium, rhodium, ruthenium, iridium, and osmium—are metals that have similar physical and chemical properties and tend to occur together in nature. PGEs are indispensable to many industrial applications but are mined in only a few places. The availability and accessibility of PGEs could be disrupted by economic, environmental, political, and social events. The United States net import reliance as a percentage of apparent consumption is about 90 percent.PGEs have many industrial applications. They are used in catalytic converters to reduce carbon monoxide, hydrocarbon, and nitrous oxide emissions in automobile exhaust. The chemical industry requires platinum or platinum-rhodium alloys to manufacture nitric oxide, which is the raw material used to manufacture explosives, fertilizers, and nitric acid. In the petrochemical industry, platinum-supported catalysts are needed to refine crude oil and to produce aromatic compounds and high-octane gasoline. Alloys of PGEs are exceptionally hard and durable, making them the best known coating for industrial crucibles used in the manufacture of chemicals and synthetic materials. PGEs are used by the glass manufacturing industry in the production of fiberglass and flat-panel and liquid crystal displays. In the electronics industry, PGEs are used in computer hard disks, hybridized integrated circuits, and multilayer ceramic capacitors.Aside from their industrial applications, PGEs are used in such other fields as health, consumer goods, and finance. Platinum, for example, is used in medical implants, such as pacemakers, and PGEs are used in cancer-fighting drugs. Platinum alloys are an ideal choice for jewelry because of their white color, strength, and resistance to tarnish. Platinum, palladium, and rhodium in the form of coins and bars are also used as investment commodities, and various financial instruments based on the value of these PGEs are traded on major exchanges

  19. Packing element of a packer

    Energy Technology Data Exchange (ETDEWEB)

    Safin, V.A.

    1982-01-01

    The packing element of a packer is proposed which consists of an elastic core and outer layer made of plastic sealing material. It is distinguished by the fact that in order to facilitate removal of the packing element from the site of installation, the outer layer has a sublayer made of polymer material which is chemically inactive in relationship to the material of the core, for example polytetrafluoroethylene. The element is also distinguished by the fact that the outer layer together with the sublayer is attached to the core through a nonhardening and nondrying glue composition, for example, based on rubber, rosin, lanolin, vaseline oil and zinc oxide.

  20. Finite element computational fluid mechanics

    Science.gov (United States)

    Baker, A. J.

    1983-01-01

    Finite element analysis as applied to the broad spectrum of computational fluid mechanics is analyzed. The finite element solution methodology is derived, developed, and applied directly to the differential equation systems governing classes of problems in fluid mechanics. The heat conduction equation is used to reveal the essence and elegance of finite element theory, including higher order accuracy and convergence. The algorithm is extended to the pervasive nonlinearity of the Navier-Stokes equations. A specific fluid mechanics problem class is analyzed with an even mix of theory and applications, including turbulence closure and the solution of turbulent flows.

  1. quadratic spline finite element method

    Directory of Open Access Journals (Sweden)

    A. R. Bahadir

    2002-01-01

    Full Text Available The problem of heat transfer in a Positive Temperature Coefficient (PTC thermistor, which may form one element of an electric circuit, is solved numerically by a finite element method. The approach used is based on Galerkin finite element using quadratic splines as shape functions. The resulting system of ordinary differential equations is solved by the finite difference method. Comparison is made with numerical and analytical solutions and the accuracy of the computed solutions indicates that the method is well suited for the solution of the PTC thermistor problem.

  2. Hadronic matrix elements for Kaons

    Energy Technology Data Exchange (ETDEWEB)

    Bijnens, Johan [Department of Theoretical Physics 2, Lund University, Soelvegatan 14A, S-22362 Lund (Sweden); Gamiz, Elvira [CAFPE and Departamento de Fisica Teorica y del Cosmos, Universidad de Granada Campus de Fuente Nueva, E-18002 Granada (Spain); Prades, Joaquim [CAFPE and Departamento de Fisica Teorica y del Cosmos, Universidad de Granada Campus de Fuente Nueva, E-18002 Granada (Spain)

    2004-07-01

    We review some work done by us calculating matrix elements for Kaons. Emphasis is put on the matrix elements which are relevant to predict non-leptonic Kaon CP violating observables. In particular, we recall our results for the B{sub K} parameter which governs the K{sup 0}-K{sup 0} mixing and update our results for {epsilon}'inK including estimated all-higher-order CHPT corrections and the new results from recent analytical calculations of the {delta}itI = 3/2 component. Some comments on future prospects on calculating matrix elements for Kaons are also added.

  3. How Certain Trace Elements Behave.

    Science.gov (United States)

    Zingaro, Ralph A.

    1979-01-01

    Fluorine, selenium, tin, and arsenic are among the trace elements occurring in the environment which are considered. Emphasis is given to developing a qualitative survey of the extent and kinds of metal transformations and their resultant effects. (CS)

  4. More frequent elements in coals

    Energy Technology Data Exchange (ETDEWEB)

    Krejci-Graf, K.

    1982-04-01

    On frequent elements in coals: in the case of bioelements (H, C, N, O) even bare quantities may offer evidence of origin and transformation of coals. With those as with other frequent elements it is not so much quantity (as is still with S), as variability, and ratios of pairs of elements, which may give evidence of transformation. Enrichments in different plants and tissues - excepting H, C, N, O - are extremely different in different samples. In coalification original contents are lowered, mixed, or veiled by import. Influences of surroundings change during the stages of coalification, while the surroundings themselves are in continual transformation. Only with frequent elements one may hope to recognize traces of original conditions. More exact knowledge of seams may help in prospection and parallelization.

  5. INDUSTRIAL DESIGN ELEMENTS IN MARKETING

    National Research Council Canada - National Science Library

    TOCARIU Liliana

    2015-01-01

    .... Marketing uses industrial design elements in order to draw up advertisements for products, to develop logos or packaging with all its attached factors, to organise promotional sales with the view...

  6. Elemental balance in soy sauce

    Energy Technology Data Exchange (ETDEWEB)

    Haruyama, Yoichi; Saito, Manabu [Kyoto Prefectural Univ., Kyoto (Japan). Lab. of Applied Physics; Yoshida, Koji

    1996-12-31

    We have measured the elemental concentrations of soy sauce and its actual raw materials which are used in a certain soy sauce factory. In the present measurement, we measured de-fatted soybean, wheat and salt as raw materials and soy sauce and soy sauce waste as final products. Five kinds of elements, such as Mn, Fe, Cu, Zn and Br, were detected. We obtained elemental concentrations of them except for Mn in each materials. The measured elemental concentration in soy sauce agreed well each other with the calculated one within the experimental errors using the measured concentration in the raw materials and their weight in actual producing process. Contrary to our expectation, it was found that wheat contributes to soy sauce bromine concentration dominantly in the present case. (author)

  7. Green's Functions and Finite Elements

    CERN Document Server

    Hartmann, Friedel

    2013-01-01

    This book elucidates how Finite Element methods look like from the perspective of Green’s functions, and shows new insights into the mathematical theory of Finite Elements. Practically, this new view on Finite Elements enables the reader to better assess solutions of standard programs and to find better model of a given problem. The book systematically introduces the basic concepts how Finite Elements fulfill the strategy of Green’s functions  and how approximating of Green’s functions. It discusses in detail the discretization error and shows that are coherent with the strategy of “goal oriented refinement”. The book also gives much attention to the dependencies of FE solutions from the parameter set of the model.

  8. Finite element methods for engineers

    CERN Document Server

    Fenner, Roger T

    2013-01-01

    This book is intended as a textbook providing a deliberately simple introduction to finite element methods in a way that should be readily understandable to engineers, both students and practising professionals. Only the very simplest elements are considered, mainly two dimensional three-noded “constant strain triangles”, with simple linear variation of the relevant variables. Chapters of the book deal with structural problems (beams), classification of a broad range of engineering into harmonic and biharmonic types, finite element analysis of harmonic problems, and finite element analysis of biharmonic problems (plane stress and plane strain). Full Fortran programs are listed and explained in detail, and a range of practical problems solved in the text. Despite being somewhat unfashionable for general programming purposes, the Fortran language remains very widely used in engineering. The programs listed, which were originally developed for use on mainframe computers, have been thoroughly updated for use ...

  9. Methane Propulsion Elements for Mars

    Science.gov (United States)

    Percy, Tom; Polsgrove, Tara; Thomas, Dan

    2017-01-01

    Human exploration beyond LEO relies on a suite of propulsive elements to: (1) Launch elements into space, (2) Transport crew and cargo to and from various destinations, (3) Provide access to the surface of Mars, (4) Launch crew from the surface of Mars. Oxygen/Methane propulsion systems meet the unique requirements of Mars surface access. A common Oxygen/Methane propulsion system is being considered to reduce development costs and support a wide range of primary & alternative applications.

  10. Programming the finite element method

    CERN Document Server

    Smith, I M; Margetts, L

    2013-01-01

    Many students, engineers, scientists and researchers have benefited from the practical, programming-oriented style of the previous editions of Programming the Finite Element Method, learning how to develop computer programs to solve specific engineering problems using the finite element method. This new fifth edition offers timely revisions that include programs and subroutine libraries fully updated to Fortran 2003, which are freely available online, and provides updated material on advances in parallel computing, thermal stress analysis, plasticity return algorithms, convection boundary c

  11. ANSYS duplicate finite-element checker routine

    Science.gov (United States)

    Ortega, R.

    1995-01-01

    An ANSYS finite-element code routine to check for duplicated elements within the volume of a three-dimensional (3D) finite-element mesh was developed. The routine developed is used for checking floating elements within a mesh, identically duplicated elements, and intersecting elements with a common face. A space shuttle main engine alternate turbopump development high pressure oxidizer turbopump finite-element model check using the developed subroutine is discussed. Finally, recommendations are provided for duplicate element checking of 3D finite-element models.

  12. New elements - approaching Z=114

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, S.

    1998-03-01

    The search for new elements is part of the broader field of investigations of nuclei at the limits of stability. In two series of experiments at SHIP, six new elements (Z=107-112) were synthesized via fusion reactions using 1n-deexcitation channels and lead or bismuth targets. The isotopes were unambiguously identified by means of {alpha}-{alpha} correlations. Not fission, but alpha decay is the dominant decay mode. The collected decay data establish a means of comparison with theoretical data. This aids in the selection of appropriate models that describe the properties of known nuclei. Predictions based on these models are useful in the preparation of the next generation of experiments. Cross-sections decrease by two orders of magnitude from bohrium (Z=107) to element 112, for which a cross-section of 1 pb was measured. The development of intense beam currents and sensitive detection methods is essential for the production and identification of still heavier elements and new isotopes of already known elements, as well as the measurement of small {alpha}-, {beta}- and fission-branching ratios. An equally sensitive set-up is needed for the measurement of excitation functions at low cross-sections. Based on our results, it is likely that the production of isotopes of element 114 close to the island of spherical super heavy elements (SHE) could be achieved by fusion reactions using {sup 208}Pb targets. Systematic studies of the reaction cross-sections indicate that the transfer of nucleons is an important process for the initiation of fusion. The data allow for the fixing of a narrow energy window for the production of SHE using 1n-emission channels. (orig.)

  13. New Perspectives on the Essential Trace Elements.

    Science.gov (United States)

    Frieden, Earl

    1985-01-01

    Provides a comprehensive overview of the 19 essential trace elements, examining: the concept of essentiality; evolution of these elements; possible future essential elements; the lanthanides and actinides; how essential trace elements work; the metalloenzymes; the nonmetals; iodine and the thyroid hormones; and antagonism among these elements. (JN)

  14. Lysets rytme som belysningsarkitektonisk element

    DEFF Research Database (Denmark)

    Bülow, Katja

    2007-01-01

    I afhandlingen "Lysets rytme som belysningsarkitektonisk element" optræder lysstofrør, neonrør, billygter og LED som lyskilder, der markerer et sted ved hjælp af et rytmisk tema. Motivationen for afhandlingen var at indkredse lyskilders rytmiske optræden som et arkitektonisk potentiale og udvide...... opfattelsen af belysningsarkitekturens virkefelt. Ofte betragtes arkitektonisk belysning som et element, der 'modulerer' - former - et stykke arkitektur visuelt, så det fremstår tydeligt i mørket. Her er lyskilden en stille statist, der sørger for at belyse omgivelserne. I den rytmiske tilgang til...... arkitektonisk belysning betragtes lyskilder, dagslys som kunstige, som agerende elementer i et landskab hvor en iagttager interagerer med lyset fra lyskilden. Denne tilgang giver mulighed for ikke kun at betragte arkitektonisk belysning som visuel repræsentation af omgivelserne, men også som en sammensætning af...

  15. Elements of spatial data quality

    CERN Document Server

    Guptill, SC

    1995-01-01

    Elements of Spatial Data Quality outlines the need and suggests potential categories for the content of a comprehensive statement of data quality that must be imbedded in the metadata that accompanies the transfer of a digital spatial data file or is available in a separate metadata catalog. Members of the International Cartographic Association's Commission on Spatial Data Quality have identified seven elements of data quality: positional accuracy, attribute accuracy, completeness, logical consistency, lineage, semantic accuracy and temporal information. In the book the authors describe: compo

  16. Fractal elements and their applications

    CERN Document Server

    Gil’mutdinov, Anis Kharisovich; El-Khazali, Reyad

    2017-01-01

    This book describes a new type of passive electronic components, called fractal elements, from a theoretical and practical point of view. The authors discuss in detail the physical implementation and design of fractal devices for application in fractional-order signal processing and systems. The concepts of fractals and fractal signals are explained, as well as the fundamentals of fractional calculus. Several implementations of fractional impedances are discussed, along with comparison of their performance characteristics. Details of design, schematics, fundamental techniques and implementation of RC-based fractal elements are provided. .

  17. FINITE ELEMENT ANALYSIS OF STRUCTURES

    Directory of Open Access Journals (Sweden)

    PECINGINA OLIMPIA-MIOARA

    2015-05-01

    Full Text Available The application of finite element method is analytical when solutions can not be applied for deeper study analyzes static, dynamic or other types of requirements in different points of the structures .In practice it is necessary to know the behavior of the structure or certain parts components of the machine under the influence of certain factors static and dynamic . The application of finite element in the optimization of components leads to economic growth , to increase reliability and durability organs studied, thus the machine itself.

  18. Finite elements of nonlinear continua

    CERN Document Server

    Oden, John Tinsley

    1972-01-01

    Geared toward undergraduate and graduate students, this text extends applications of the finite element method from linear problems in elastic structures to a broad class of practical, nonlinear problems in continuum mechanics. It treats both theory and applications from a general and unifying point of view.The text reviews the thermomechanical principles of continuous media and the properties of the finite element method, and then brings them together to produce discrete physical models of nonlinear continua. The mathematical properties of these models are analyzed, along with the numerical s

  19. Multiphoton spectroscopy in heavy elements

    Energy Technology Data Exchange (ETDEWEB)

    Solarz, R.W.; Paisner, J.A.; Worden, E.F.

    1977-05-03

    Some recently discovered regularities in the spectra of heavy elements which are also applicable to the analysis of the spectra of lighter atoms are described. It is pointed out that stepwise resonant multiphoton methods are irreplaceable tools in the study of high lying states in a complex atomic system. Systematic applications of these methods has permitted regularities to be observed which also hold for the lighter elements. It is noted that greatly increased understanding of the excited state structure of heavy atoms is not possible. 8 references. (JFP)

  20. Transposable elements and circular DNAs

    KAUST Repository

    Mourier, Tobias

    2016-09-26

    Circular DNAs are extra-chromosomal fragments that become circularized by genomic recombination events. We have recently shown that yeast LTR elements generate circular DNAs through recombination events between their flanking long terminal repeats (LTRs). Similarly, circular DNAs can be generated by recombination between LTRs residing at different genomic loci, in which case the circular DNA will contain the intervening sequence. In yeast, this can result in gene copy number variations when circles contain genes and origins of replication. Here, I speculate on the potential and implications of circular DNAs generated through recombination between human transposable elements.

  1. Nuclear fuel elements design, fabrication and performance

    CERN Document Server

    Frost, Brian R T

    1982-01-01

    Nuclear Fuel Elements: Design, Fabrication and Performance is concerned with the design, fabrication, and performance of nuclear fuel elements, with emphasis on fast reactor fuel elements. Topics range from fuel types and the irradiation behavior of fuels to cladding and duct materials, fuel element design and modeling, fuel element performance testing and qualification, and the performance of water reactor fuels. Fast reactor fuel elements, research and test reactor fuel elements, and unconventional fuel elements are also covered. This volume consists of 12 chapters and begins with an overvie

  2. Spectral element simulation of ultrafiltration

    DEFF Research Database (Denmark)

    Hansen, M.; Barker, Vincent A.; Hassager, Ole

    1998-01-01

    A spectral element method for simulating stationary 2-D ultrafiltration is presented. The mathematical model is comprised of the Navier-Stokes equations for the velocity field of the fluid and a transport equation for the concentration of the solute. In addition to the presence of the velocity ve....... The performance of the spectral element code when applied to several ultrafiltration problems is reported. (C) 1998 Elsevier Science Ltd. All rights reserved.......A spectral element method for simulating stationary 2-D ultrafiltration is presented. The mathematical model is comprised of the Navier-Stokes equations for the velocity field of the fluid and a transport equation for the concentration of the solute. In addition to the presence of the velocity...... vector in the transport equation, the system is coupled by the dependency of the fluid viscosity on the solute concentration and by a concentration-dependent boundary condition for the Navier-Stokes equations at the membrane surface. The spectral element discretization yields a nonlinear algebraic system...

  3. Names of the Heavier Elements

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 3. Names of the Heavier Elements. Jitendra K Bera. General Article Volume 4 Issue 3 March 1999 pp 53-61. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/004/03/0053-0061. Author Affiliations.

  4. Main Elements for Upscaling Recreation

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Termansen, Mette

    2012-01-01

    This report provides information on the main elements used to scale up modelled local visitor flow data to regional level based on recreational de-mand models. These models are described in Report #1. This report also provides information on data sources such as spatial data (e.g. land cov...

  5. Environmental research on actinide elements

    Energy Technology Data Exchange (ETDEWEB)

    Pinder, J.E. III; Alberts, J.J.; McLeod, K.W.; Schreckhise, R.G. (eds.)

    1987-08-01

    The papers synthesize the results of research sponsored by DOE's Office of Health and Environmental Research on the behavior of transuranic and actinide elements in the environment. Separate abstracts have been prepared for the 21 individual papers. (ACR)

  6. Superheavy elements and decay properties

    Indian Academy of Sciences (India)

    2015-08-04

    Aug 4, 2015 ... Home; Journals; Pramana – Journal of Physics; Volume 85; Issue 3. Superheavy elements and decay properties. K P Santhosh. Volume 85 Issue 3 ... Author Affiliations. K P Santhosh1. School of Pure and Applied Physics, Kannur University, Swami Anandatheertha Campus, Payyanur 670 327, India ...

  7. Quadrilateral finite element mesh coarsening

    Science.gov (United States)

    Staten, Matthew L; Dewey, Mark W; Benzley, Steven E

    2012-10-16

    Techniques for coarsening a quadrilateral mesh are described. These techniques include identifying a coarsening region within the quadrilateral mesh to be coarsened. Quadrilateral elements along a path through the coarsening region are removed. Node pairs along opposite sides of the path are identified. The node pairs along the path are then merged to collapse the path.

  8. Backfire antennas with dipole elements

    DEFF Research Database (Denmark)

    Nielsen, Erik Dragø; Pontoppidan, Knud

    1970-01-01

    A method is set up for a theoretical investigation of arbitrary backfire antennas based upon dipole structures. The mutual impedance between the dipole elements of the antenna is taken into account, and the field radiated due to a surface wave reflector of finite extent is determined by calculating...

  9. Actinomycete integrative and conjugative elements

    NARCIS (Netherlands)

    Poele, Evelien M. te; Bolhuis, Henk; Dijkhuizen, Lubbert

    This paper reviews current knowledge on actinomycete integrative and conjugative elements (AICEs). The best characterised AICEs, pSAM2 of Streptomyces ambofaciens (10.9 kb), SLP1 (17.3 kb) of Streptomyces coelicolor and pMEA300 of Amycolatopsis methanolica (13.3 kb), are present as integrative

  10. Actinomycete integrative and conjugative elements

    NARCIS (Netherlands)

    Te Poele, E.M.; Bolhuis, H.; Dijkhuizen, L.

    2008-01-01

    This paper reviews current knowledge on actinomycete integrative and conjugative elements (AICEs). The best characterised AICEs, pSAM2 of Streptomyces ambofaciens (10.9 kb), SLP1 (17.3 kb) of Streptomyces coelicolor and pMEA300 of Amycolatopsis methanolica (13.3 kb), are present as integrative

  11. Names of the Heavier Elements

    Indian Academy of Sciences (India)

    Applied Chemistry (IUPAC) and the International Union of. Pure and Applied Physics (IUPAP) to look into the problem of pri ori ty of discovery of the elements with nuclear charge number. Z > 100. The two Unions selected the members of the group consisting of nine scientists in nuclear physics and chemistry in. 1987.

  12. Trace elements: implications for nursing.

    Science.gov (United States)

    Hayter, J

    1980-01-01

    Although most were unknown a few years ago, present evidence indicates that at least 25 trace elements have some pertinence to health. Unlike vitamins, they cannot be synthesized. Some trace elements are now considered important only because of their harmful effects but traces of them may be essential. Zinc is especially important during puberty, pregnancy and menopause and is related to protein metabolism. Both fluoride and cadmium accumulate in the body year after year. Cadmium is positively correlated with several chronic diseases, especially hypertension. It is obtained from smoking and drinking soft water. Silicon, generally associated with silicosis, may be necessary for healthy bone and connective tissue. Chromium, believed to be the glucose tolerance factor, is obtained from brewer's yeast, spices, and whole wheat products. Copper deficiency may be implicated in a wide range of cardiovascular and blood related disorders. Either marginal deficiencies or slight excesses of most trace elements are harmful. Nurses should instruct patients to avoid highly refined foods, fad diets, or synthetic and fabricated foods. A well balanced and varied diet is the best safeguard against trace element excesses or deficiencies.

  13. Power flow for Josephson elements.

    Science.gov (United States)

    Thompson, E. D.

    1973-01-01

    General relations are presented for the power flow at the frequencies of interest in a Josephson element. These general power flow relations depend upon whether the autonomous frequency is phase-locked, either harmonically or subharmonically, to a frequency in the system or is unlocked. The results presented generalize those given previously by Russer (1971) for the harmonically locked case.

  14. Kinematic support using elastic elements

    Science.gov (United States)

    Geirsson, Arni; Debra, Daniel B.

    1988-01-01

    The design of kinematic supports using elastic elements is reviewed. The two standard methods (cone, Vee and flat and three Vees) are presented and a design example involving a machine tool metrology bench is given. Design goals included thousandfold strain attenuation in the bench relative to the base when the base strains due to temperature variations and shifting loads. Space applications are also considered.

  15. Scarcity of rare earth elements

    NARCIS (Netherlands)

    de Boer, M.A.; Lammertsma, K.

    2013-01-01

    Rare earth elements (REEs) are important for green and a large variety of high-tech technologies and are, therefore, in high demand. As a result, supply with REEs is likely to be disrupted (the degree of depends on the REE) in the near future. The 17 REEs are divided into heavy and light REEs. Other

  16. Compact Fuel Element Environment Test

    Science.gov (United States)

    Bradley, D. E.; Mireles, O. R.; Hickman, R. R.; Broadway, J. W.

    2012-01-01

    Deep space missions with large payloads require high specific impulse (I(sub sp)) and relatively high thrust to achieve mission goals in reasonable time frames. Conventional, storable propellants produce average I(sub sp). Nuclear thermal rockets (NTRs) capable of high I(sub sp) thrust have been proposed. NTR employs heat produced by fission reaction to heat and therefore accelerate hydrogen, which is then forced through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3,000 K) and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high-temperature hydrogen exposure on fuel elements are limited. The primary concern is the mechanical failure of fuel elements that employ high melting point metals, ceramics, or a combination (cermet) as a structural matrix into which the nuclear fuel is distributed. It is not necessary to include fissile material in test samples intended to explore high-temperature hydrogen exposure of the structural support matrices. A small-scale test bed designed to heat fuel element samples via noncontact radio frequency heating and expose samples to hydrogen for typical mission durations has been developed to assist in optimal material and manufacturing process selection without employing fissile material. This Technical Memorandum details the test bed design and results of testing conducted to date.

  17. sources of the chemical elements

    African Journals Online (AJOL)

    ABSTRACT. Major and trace element compositions of samples ofBanded. Iron Formations (BIF) from the Neoarchaean Sukumaland. Greenstone Belt of Geita in northern Tanzania reveal that the. BIF precipitated from hydrothermal solutions. Fe-Ti-Al-Mn systematics suggest that the hydrothermal deposits have been.

  18. Presidential elements in government: introduction

    NARCIS (Netherlands)

    Reestman, J.H.

    2006-01-01

    The editorial board of the European Constitutional Law Review has solicited a number of contributions on presidential elements in government systems in Europe. At the origin of the project are some recent sweeping interventions of heads of state in the political arena. These are notably the

  19. Random matrix theory for pseudo-Hermitian systems: Cyclic blocks

    Indian Academy of Sciences (India)

    tems, and, for Hamiltonians that break parity P and time-reversal invariance T. In an attempt to understand the ... Keywords. Random matrices; circulants; quantum chaos; PT symmetry; pseudo-. Hermiticity. ... local fluctuation properties of complex quantum systems have universal properties, independent of the details of the ...

  20. Spectral Radii of Large Non-Hermitian Random Matrices

    OpenAIRE

    Jiang, Tiefeng; Qi, Yongcheng

    2014-01-01

    By using the independence structure of points following a determinantal point process, we study the radii of the spherical ensemble, the truncation of the circular unitary ensemble and the product ensemble with parameter n and k. The limiting distributions of the three radii are obtained. They are not the Tracy-Widom distribution. In particular, for the product ensemble, we show that the limiting distribution has a transition phenomenon: when k/n -> 0, k/n -> a in (0,infty) and k/n -> infty, ...

  1. Theory of non-hermitian localization in one dimension: Localization ...

    Indian Academy of Sciences (India)

    We recall some basic aspects of the pinning of flux lines in a superconducting cylindrical shell subjected to a depinning magnetic field, as well as its description by the quantum mechanics of a disordered ring with an imaginary vector potential proportional to the depinning field (N Hatano and D R Nelson, Phys. Rev. B56 ...

  2. Superheavy-element spectroscopy: Correlations along element 115 decay chains

    Directory of Open Access Journals (Sweden)

    Rudolph D.

    2016-01-01

    Full Text Available Following a brief summary of the region of the heaviest atomic nuclei yet created in the laboratory, data on more than hundred α-decay chains associated with the production of element 115 are combined to investigate time and energy correlations along the observed decay chains. Several of these are analysed using a new method for statistical assessments of lifetimes in sets of decay chains.

  3. Superheavy-element spectroscopy: Correlations along element 115 decay chains

    Science.gov (United States)

    Rudolph, D.; Forsberg, U.; Sarmiento, L. G.; Golubev, P.; Fahlander, C.

    2016-05-01

    Following a brief summary of the region of the heaviest atomic nuclei yet created in the laboratory, data on more than hundred α-decay chains associated with the production of element 115 are combined to investigate time and energy correlations along the observed decay chains. Several of these are analysed using a new method for statistical assessments of lifetimes in sets of decay chains.

  4. Superheavy-element spectroscopy: Correlations along element 115 decay chains

    OpenAIRE

    Rudolph D.; Forsberg U.; Sarmiento L.G.; Golubev P.; Fahlander C.

    2016-01-01

    Following a brief summary of the region of the heaviest atomic nuclei yet created in the laboratory, data on more than hundred α-decay chains associated with the production of element 115 are combined to investigate time and energy correlations along the observed decay chains. Several of these are analysed using a new method for statistical assessments of lifetimes in sets of decay chains.

  5. 49 CFR 563.7 - Data elements.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Data elements. 563.7 Section 563.7 Transportation..., DEPARTMENT OF TRANSPORTATION EVENT DATA RECORDERS § 563.7 Data elements. (a) Data elements required for all vehicles. Each vehicle equipped with an EDR must record all of the data elements listed in Table I, during...

  6. Reliability-Based Optimization of Structural Elements

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    In this paper structural elements from an optimization point of view are considered, i.e. only the geometry of a structural element is optimized. Reliability modelling of the structural element is discussed both from an element point of view and from a system point of view. The optimization...

  7. Solución bidimensional sin malla de la ecuación no lineal de convección-difusión-reacción mediante el método de Interpolación Local Hermítica Two-dimensional meshless solution of the non-linear convection diffusion reaction equation by the Local Hermitian Interpolation method

    Directory of Open Access Journals (Sweden)

    Carlos A Bustamante Chaverra

    2013-03-01

    Full Text Available Un método sin malla es desarrollado para solucionar una versión genérica de la ecuación no lineal de convección-difusión-reacción en dominios bidimensionales. El método de Interpolación Local Hermítica (LHI es empleado para la discretización espacial, y diferentes estrategias son implementadas para solucionar el sistema de ecuaciones no lineales resultante, entre estas iteración de Picard, método de Newton-Raphson y el Método de Homotopía truncado (HAM. En el método LHI las Funciones de Base Radial (RBFs son empleadas para construir una función de interpolación. A diferencia del Método de Kansa, el LHI es aplicado localmente y los operadores diferenciales de las condiciones de frontera y la ecuación gobernante son utilizados para construir la función de interpolación, obteniéndose una matriz de colocación simétrica. El método de Newton-Rapshon se implementa con matriz Jacobiana analítica y numérica, y las derivadas de la ecuación gobernante con respecto al paramétro de homotopía son obtenidas analíticamente. El esquema numérico es verificado mediante la comparación de resultados con las soluciones analíticas de las ecuaciones de Burgers en una dimensión y Richards en dos dimensiones. Similares resultados son obtenidos para todos los solucionadores que se probaron, pero mejores ratas de convergencia son logradas con el método de Newton-Raphson en doble iteración.A meshless numerical scheme is developed for solving a generic version of the non-linear convection-diffusion-reaction equation in two-dim-ensional domains. The Local Hermitian Interpolation (LHI method is employed for the spatial discretization and several strategies are implemented for the solution of the resulting non-linear equation system, among them the Picard iteration, the Newton Raphson method and a truncated version of the Homotopy Analysis Method (HAM. The LHI method is a local collocation strategy in which Radial Basis Functions (RBFs

  8. Stress relaxation of constructions elements

    Directory of Open Access Journals (Sweden)

    Larionov Evgeniy

    2017-01-01

    Full Text Available A relaxation of stress in the elements of constructions is considered and an approach is proposed for solution of corresponding problems. It is notable that this approach is based on a modification Boltzmann’s principle superposition of fraction creep deformations. This modification reduces the noted problems to solution of linear relative to so-called structural stress integral equations. Next a desired stress is defined by solution of algebraic equations. It should be underline that a material (concrete, steel, graph of elements a considered as a union of its fractions with statistical disturbed strengths. This ascending to Weibull conception [1] permits to modify Boltzmann’s principle superposition [2]. As a result this principle is applicable when a dependence on deformations from the stresses is nonlinear [3-7].

  9. Transposable elements and psychiatric disorders.

    Science.gov (United States)

    Guffanti, Guia; Gaudi, Simona; Fallon, James H; Sobell, Janet; Potkin, Steven G; Pato, Carlos; Macciardi, Fabio

    2014-04-01

    Transposable Elements (TEs) or transposons are low-complexity elements (e.g., LINEs, SINEs, SVAs, and HERVs) that make up to two-thirds of the human genome. There is mounting evidence that TEs play an essential role in genomic architecture and regulation related to both normal function and disease states. Recently, the identification of active TEs in several different human brain regions suggests that TEs play a role in normal brain development and adult physiology and quite possibly in psychiatric disorders. TEs have been implicated in hemophilia, neurofibromatosis, and cancer. With the advent of next-generation whole-genome sequencing approaches, our understanding of the relationship between TEs and psychiatric disorders will greatly improve. We will review the biology of TEs and early evidence for TE involvement in psychiatric disorders. © 2014 Wiley Periodicals, Inc.

  10. Automation of finite element methods

    CERN Document Server

    Korelc, Jože

    2016-01-01

    New finite elements are needed as well in research as in industry environments for the development of virtual prediction techniques. The design and implementation of novel finite elements for specific purposes is a tedious and time consuming task, especially for nonlinear formulations. The automation of this process can help to speed up this process considerably since the generation of the final computer code can be accelerated by order of several magnitudes. This book provides the reader with the required knowledge needed to employ modern automatic tools like AceGen within solid mechanics in a successful way. It covers the range from the theoretical background, algorithmic treatments to many different applications. The book is written for advanced students in the engineering field and for researchers in educational and industrial environments.

  11. FUEL ELEMENT FOR NUCLEAR REACTORS

    Science.gov (United States)

    Bassett, C.H.

    1961-11-21

    A fuel element is designed which is particularly adapted for reactors of high power density used to generate steam for the production of electricity. The fuel element consists of inner and outer concentric tubes forming an annular chamber within which is contained fissionable fuel pellet segments, wedge members interposed between the fuel segments, and a spring which, acting with wedge members, urges said fuel pellets radially into contact against the inner surface of the outer tube. The wedge members may be a fertile material convertible into fissionable fuel material by absorbing neutrons emitted from the fissionable fuel pellet segments. The costly grinding of cylindrical fuel pellets to close tolerances for snug engagement is reduced because the need to finish the exact size is eliminated. (AEC)

  12. Representation Elements of Spatial Thinking

    Science.gov (United States)

    Fiantika, F. R.

    2017-04-01

    This paper aims to add a reference in revealing spatial thinking. There several definitions of spatial thinking but it is not easy to defining it. We can start to discuss the concept, its basic a forming representation. Initially, the five sense catch the natural phenomenon and forward it to memory for processing. Abstraction plays a role in processing information into a concept. There are two types of representation, namely internal representation and external representation. The internal representation is also known as mental representation; this representation is in the human mind. The external representation may include images, auditory and kinesthetic which can be used to describe, explain and communicate the structure, operation, the function of the object as well as relationships. There are two main elements, representations properties and object relationships. These elements play a role in forming a representation.

  13. Finite elements methods in mechanics

    CERN Document Server

    Eslami, M Reza

    2014-01-01

    This book covers all basic areas of mechanical engineering, such as fluid mechanics, heat conduction, beams, and elasticity with detailed derivations for the mass, stiffness, and force matrices. It is especially designed to give physical feeling to the reader for finite element approximation by the introduction of finite elements to the elevation of elastic membrane. A detailed treatment of computer methods with numerical examples are provided. In the fluid mechanics chapter, the conventional and vorticity transport formulations for viscous incompressible fluid flow with discussion on the method of solution are presented. The variational and Galerkin formulations of the heat conduction, beams, and elasticity problems are also discussed in detail. Three computer codes are provided to solve the elastic membrane problem. One of them solves the Poisson’s equation. The second computer program handles the two dimensional elasticity problems, and the third one presents the three dimensional transient heat conducti...

  14. Linear and Nonlinear Finite Elements.

    Science.gov (United States)

    1983-12-01

    Yang, Matrix displacement solution to elastica problems of beams and frames , Internat. J. Solids Structures 9 (1973) 829-842. [51 W.F. Schmidt...nonlinear finite element analysis of beams, frames . arches and axisymmetric shells. Comput. and Structures 7 (1977) 725-735. 171 1. Fried. The Numerical...extension. Near inexten bility is achieved with a high dostic constant . ,p -P+(.(l-)+Q? (3) Lare axial stilness gives rise to strong oscmations in

  15. Elements of Bayesian experimental design

    Energy Technology Data Exchange (ETDEWEB)

    Sivia, D.S. [Rutherford Appleton Lab., Oxon (United Kingdom)

    1997-09-01

    We consider some elements of the Bayesian approach that are important for optimal experimental design. While the underlying principles used are very general, and are explained in detail in a recent tutorial text, they are applied here to the specific case of characterising the inferential value of different resolution peakshapes. This particular issue was considered earlier by Silver, Sivia and Pynn (1989, 1990a, 1990b), and the following presentation confirms and extends the conclusions of their analysis.

  16. Blade-element/momentum theory

    DEFF Research Database (Denmark)

    Sørensen, Jens Nørkær

    2016-01-01

    Although there exists a large variety of methods for predicting performance and loadings of wind turbines, the only approach used today by wind turbine manufacturers is based on the blade-element/momentum (BEM) theory by Glauert (Aerodynamic theory. Springer, Berlin, pp. 169-360, 1935). A basic...... assumption in the BEM theory is that the flow takes place in independent stream tubes and that the loading is determined from two-dimensional sectional airfoil characteristics....

  17. Adobe Photoshop Elements 10 unleash the hidden performance of Elements

    CERN Document Server

    Galer, Mark

    2011-01-01

    Master the most powerful photo editing tools and techniques that Elements has to offer! Using step-by-step projects, Mark Galer will have you creating stunning images in no time at all. Whether you want to create impressive, seamless montages, optimize your photos for perfect print quality, or simply enhance your images for maximum impact, Maximum Performance will give you the skills and know-how you need to create professional quality results. Featured projects teach you how to work with multilayered 16 bit/channel files, as well as convert to black and white using Adobe Camera Raw, create

  18. Peridynamic Multiscale Finite Element Methods

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Timothy [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bond, Stephen D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Littlewood, David John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Moore, Stan Gerald [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

    The problem of computing quantum-accurate design-scale solutions to mechanics problems is rich with applications and serves as the background to modern multiscale science research. The prob- lem can be broken into component problems comprised of communicating across adjacent scales, which when strung together create a pipeline for information to travel from quantum scales to design scales. Traditionally, this involves connections between a) quantum electronic structure calculations and molecular dynamics and between b) molecular dynamics and local partial differ- ential equation models at the design scale. The second step, b), is particularly challenging since the appropriate scales of molecular dynamic and local partial differential equation models do not overlap. The peridynamic model for continuum mechanics provides an advantage in this endeavor, as the basic equations of peridynamics are valid at a wide range of scales limiting from the classical partial differential equation models valid at the design scale to the scale of molecular dynamics. In this work we focus on the development of multiscale finite element methods for the peridynamic model, in an effort to create a mathematically consistent channel for microscale information to travel from the upper limits of the molecular dynamics scale to the design scale. In particular, we first develop a Nonlocal Multiscale Finite Element Method which solves the peridynamic model at multiple scales to include microscale information at the coarse-scale. We then consider a method that solves a fine-scale peridynamic model to build element-support basis functions for a coarse- scale local partial differential equation model, called the Mixed Locality Multiscale Finite Element Method. Given decades of research and development into finite element codes for the local partial differential equation models of continuum mechanics there is a strong desire to couple local and nonlocal models to leverage the speed and state of the

  19. Element-by-element and implicit-explicit finite element formulations for computational fluid dynamics

    Science.gov (United States)

    Tezduyar, T. E.; Liou, J.

    1988-01-01

    Preconditioner algorithms to reduce the computational effort in FEM analyses of large-scale fluid-dynamics problems are presented. A general model problem is constructed on the basis of the convection-diffusion equation and the two-dimensional vorticity/stream-function formulation of the Navier-Stokes equations; this problem is then analyzed using element-by-element, implicit-explicit, and adaptive implicit-explicit approximation schemes. Numerical results for the two-dimensional advection and rigid-body rotation of a cosine hill, flow past a circular cylinder, and driven cavity flow are presented in extensive graphs and shown to be in good agreement with those obtained using implicit methods.

  20. Element-by-element parallel spectral-element methods for 3-D teleseismic wave modeling

    KAUST Repository

    Liu, Shaolin

    2017-09-28

    The development of an efficient algorithm for teleseismic wave field modeling is valuable for calculating the gradients of the misfit function (termed misfit gradients) or Fréchet derivatives when the teleseismic waveform is used for adjoint tomography. Here, we introduce an element-by-element parallel spectral-element method (EBE-SEM) for the efficient modeling of teleseismic wave field propagation in a reduced geology model. Under the plane-wave assumption, the frequency-wavenumber (FK) technique is implemented to compute the boundary wave field used to construct the boundary condition of the teleseismic wave incidence. To reduce the memory required for the storage of the boundary wave field for the incidence boundary condition, a strategy is introduced to efficiently store the boundary wave field on the model boundary. The perfectly matched layers absorbing boundary condition (PML ABC) is formulated using the EBE-SEM to absorb the scattered wave field from the model interior. The misfit gradient can easily be constructed in each time step during the calculation of the adjoint wave field. Three synthetic examples demonstrate the validity of the EBE-SEM for use in teleseismic wave field modeling and the misfit gradient calculation.

  1. Computational Fluid Dynamics (CFD): Element-by-Element Analysis for Advanced Computers

    Science.gov (United States)

    1988-11-14

    WORK UNIT ELEMENT NO. NO. NO. ACCESSION NO 11. TITLE (Include Y’ecurity Classification) Computational Fluid Dynamics ( CFD ): Element-by-Element...All other editions are obsolete. V L ?, AFOSR Report Grant #AFOSR-87-0153 Computational Fluid Dynamics ( CFD ): Element-by-Element Analysis for Advanced

  2. 7 CFR 29.6081 - Elements of quality and degrees of each element.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.6081 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  3. 7 CFR 29.1101 - Elements of quality and degrees of each element.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.1101 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  4. 7 CFR 29.3586 - Elements of quality and degrees of each element.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.3586 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  5. 7 CFR 29.2351 - Elements of quality and degrees of each element.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.2351 Elements of quality and degrees of each element. Tobacco attributes or characteristics which constitute quality are...

  6. 7 CFR 29.2601 - Elements of quality and degrees of each element.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.2601 Elements of quality and degrees of each element. Tobacco attributes or characteristics which constitute quality are...

  7. 7 CFR 29.3101 - Elements of quality and degrees of each element.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.3101 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  8. Duration judgements over multiple elements

    Directory of Open Access Journals (Sweden)

    Inci eAyhan

    2012-11-01

    Full Text Available We investigated the limits of the number of events observers can simultaneously time. For single targets occurring in one of eight positions sensitivity to duration was improved for spatially pre-cued items as compared to post-cued items indicating that exogenous driven attention can improve duration discrimination. Sensitivity to duration for pre-cued items was also marginally better for single items as compared to eight items indicating that even after the allocation of focal attention, distracter items can interfere with the encoding of duration. For an eight item array discrimination was worse for post-cued locations as compared to pre-cued locations indicating both that attention can improve duration discrimination performance and that it was not possible to access a perfect memory trace of the duration of eight elements. The interference from the distracters in the pre-cued eight item array may reflect some mandatory averaging of target and distracter events. To further explore duration averaging we asked subjects to explicitly compare average durations of multiple item arrays against a single item standard duration. Duration discrimination thresholds were significantly lower for single elements as compared to multiple elements, showing that averaging, either automatically or intentionally, impairs duration discrimination. There was no set size effect. Performance was the same for averages of two and eight items, but performance with even an average of two items was worse than for one item. This was also true for sequential presentation indicating poor performance was not due to limits on the division of attention across items. Rather performance appears to be limited by an inability to remember or aggregate duration information from two or more items. Although it is possible to manipulate perceived duration locally, there appears to be no perceptual mechanisms for aggregating local durations across space.

  9. Fluidic Elements based on Coanda Effect

    Directory of Open Access Journals (Sweden)

    Constantin OLIVOTTO

    2010-12-01

    Full Text Available This paper contains first some definitions and classifications regarding the fluidic elements. Thegeneral current status is presented, nominating the main specific elements based on the Coanda effect developedspecially in Romania. In particularly the development of an original bistable element using industrial compressedair at industrial pressure supply is presented. The function of this element is based on the controlled attachmentof the main jet at a curved wall through the Coanda effect. The methods used for particular calculation andexperiments are nominated. The main application of these elements was to develop a specific execution element:a fluidic step–by-step motor based on the Coanda effect.

  10. INDUSTRIAL DESIGN ELEMENTS IN MARKETING

    Directory of Open Access Journals (Sweden)

    TOCARIU Liliana

    2015-06-01

    Full Text Available Industrial design represents an important 20th century phenomenon, which contributed to the spectacular development of human society. There are a lot of domains in which the insertion of the industrial design methods and theories is extremely necessary, becoming common practice. Marketing uses industrial design elements in order to draw up advertisements for products, to develop logos or packaging with all its attached factors, to organise promotional sales with the view of penetrating a certain market or of appealing to a large number of consumers.

  11. Elements of abstract harmonic analysis

    CERN Document Server

    Bachman, George

    2013-01-01

    Elements of Abstract Harmonic Analysis provides an introduction to the fundamental concepts and basic theorems of abstract harmonic analysis. In order to give a reasonably complete and self-contained introduction to the subject, most of the proofs have been presented in great detail thereby making the development understandable to a very wide audience. Exercises have been supplied at the end of each chapter. Some of these are meant to extend the theory slightly while others should serve to test the reader's understanding of the material presented. The first chapter and part of the second give

  12. Elements of partial differential equations

    CERN Document Server

    Sneddon, Ian N

    2006-01-01

    Geared toward students of applied rather than pure mathematics, this volume introduces elements of partial differential equations. Its focus is primarily upon finding solutions to particular equations rather than general theory.Topics include ordinary differential equations in more than two variables, partial differential equations of the first and second orders, Laplace's equation, the wave equation, and the diffusion equation. A helpful Appendix offers information on systems of surfaces, and solutions to the odd-numbered problems appear at the end of the book. Readers pursuing independent st

  13. Canonical elements of rotational motion

    Science.gov (United States)

    Fukushima, T.

    2009-09-01

    We present a new set of canonical variables to describe general rotation of a triaxial rigid body. Explicit are both the forward and backward transformations from the new variables to the Andoyer canonical variables, which are universal. The rotational kinetic energy is expressed as a quadratic monomial of one new momentum. Consequently, the torque-free rotations are expressed as a linear function of time for the conjugate coordinate and constants of time for the rest two coordinates and three momenta. This means that the new canonical variables are universal elements in a broad sense.

  14. Basic Elements of Knowledge Management

    Directory of Open Access Journals (Sweden)

    Marcin W. Staniewski

    2007-10-01

    Full Text Available The article is a review of basic knowledge management terminology. It presents such a description as: knowledge resources levels (data, information, knowledge, and wisdom, knowledge sources (internal, external, and knowledge typology (implicit, tacit or individual, social. Moreover the article characterizes knowledge management process, knowledge management system and main knowledge management strategies (codification, personalization. At the end of the article there is mentioned the knowledge creating process (the concept of knowledge creation spiral and the role of Intelligence Technology (IT and organizational culture as main elements supporting knowledge management implementation in organizations.

  15. Elemental composition of Malawian rice.

    Science.gov (United States)

    Joy, Edward J M; Louise Ander, E; Broadley, Martin R; Young, Scott D; Chilimba, Allan D C; Hamilton, Elliott M; Watts, Michael J

    2017-08-01

    Widespread potential dietary deficiencies of calcium (Ca), iron (Fe), iodine (I), selenium (Se) and zinc (Zn) have been identified in Malawi. Several deficiencies are likely to be compounded by high phytic acid (PA) consumption. Rice (Oryza sativa) is commonly consumed in some Malawian populations, and its mineral micronutrient content is important for food security. The considerable irrigation requirements and flooded conditions of paddy soils can also introduce or mobilise potentially toxic elements including arsenic (As), cadmium (Cd) and lead (Pb). The aim of this study was to determine the mineral composition of rice sampled from farmers' fields and markets in Malawi. Rice was sampled from 18 extension planning areas across Malawi with 21 white (i.e. polished) and 33 brown samples collected. Elemental composition was determined by inductively coupled plasma-mass spectrometry (ICP-MS). Arsenic speciation was performed using high-performance liquid chromatography (HPLC)-ICP-MS. Concentration of PA was determined using a PA-total phosphorus assay. Median total concentrations (mg kg-1, dry weight) of elements important for human nutrition in brown and white rice, respectively, were: Ca = 66.5 and 37.8; Cu = 3.65 and 2.49; Fe = 22.1 and 7.2; I = 0.006 and elements (mg kg-1, dry weight) in brown and white rice samples, respectively, were: As = 0.030 and 0.006; Cd  ≤ 0.002 and 0.006; Pb = 0.008 and 0.008. Approximately 95 % of As was found to be inorganic As, where this could be quantified. Malawian rice, like the more widely consumed staple grain maize, contains inadequate Ca, I, Se or Zn to meet dietary requirements. Biofortification strategies could significantly increase Se and Zn concentrations and require further investigation. Concentrations of Fe in rice grain varied greatly, and this was likely due to contamination of rice samples with soil. Risk of As, Cd or Pb toxicity due to rice consumption in Malawi appears to be minimal.

  16. Essential Grid Workflow Monitoring Elements

    Energy Technology Data Exchange (ETDEWEB)

    Gunter, Daniel K.; Jackson, Keith R.; Konerding, David E.; Lee,Jason R.; Tierney, Brian L.

    2005-07-01

    Troubleshooting Grid workflows is difficult. A typicalworkflow involves a large number of components networks, middleware,hosts, etc. that can fail. Even when monitoring data from all thesecomponents is accessible, it is hard to tell whether failures andanomalies in these components are related toa given workflow. For theGrid to be truly usable, much of this uncertainty must be elim- inated.We propose two new Grid monitoring elements, Grid workflow identifiersand consistent component lifecycle events, that will make Gridtroubleshooting easier, and thus make Grids more usable, by simplifyingthe correlation of Grid monitoring data with a particular Gridworkflow.

  17. Analytical chemistry of transuranium elements

    Energy Technology Data Exchange (ETDEWEB)

    Myasoedov, B.F. (V.I. Vernadsky Inst. of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation)); Lebedev, I.A. (V.I. Vernadsky Inst. of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation))

    1993-02-01

    Recently developed new methods of isolation and determination of transuranium elements (TUE), which are used to analyse nuclear fuel and products of its recovery as well as natural objects, are described in this paper. Solvent extraction, sorption and precipitation methods of TUE separation are considered. Among methods of determination, radiometric, X-ray fluorescence, mass spectrometry, emission spectroscopy, atomic absorption, coulometry, spectrophotometry and titrimetry methods are discussed. Special attention is given to the methods which permit to determine super low concentrations of TUE or to perform analyses with maximum accuracy. (orig.)

  18. Elements of partial differential equations

    CERN Document Server

    Sneddon, Ian Naismith

    1957-01-01

    Geared toward students of applied rather than pure mathematics, this volume introduces elements of partial differential equations. Its focus is primarily upon finding solutions to particular equations rather than general theory.Topics include ordinary differential equations in more than two variables, partial differential equations of the first and second orders, Laplace's equation, the wave equation, and the diffusion equation. A helpful Appendix offers information on systems of surfaces, and solutions to the odd-numbered problems appear at the end of the book. Readers pursuing independent st

  19. Infrared activity in elemental crystals

    Science.gov (United States)

    Zallen, Richard; Martin, Richard M.; Natoli, Vincent

    1994-03-01

    In a previous paper, Zallen [Phys. Rev. 173, 824 (1968)] reported a group-theoretical analysis of the competition between unit-cell complexity and crystal symmetry in determining the presence or absence of infrared-active phonons in an elemental crystal. Here we correct an error in that paper's treatment of certain hexagonal space groups. Our results modify the minimum-complexity condition for infrared activity: For 228 of the 230 space groups, a necessary and sufficient condition for the existence of symmetry-allowed infrared-active modes in an elemental crystal is the presence of three or more atoms in the primitive unit cell. The two exceptional space groups are P6/mmm (D16h) and P63/mmc (D46h); for each of these symmetries, there exists one structure with four atoms per cell and no infrared modes. The P63/mmc structure includes, as special cases, Lonsdaleite (or ``wurtzite silicon'') as well as a c-axis-aligned hcp arrangement of diatomic molecules which is relevant to models of solid molecular hydrogen at high pressure.

  20. Scarcity of rare earth elements.

    Science.gov (United States)

    de Boer, M A; Lammertsma, K

    2013-11-01

    Rare earth elements (REEs) are important for green and a large variety of high-tech technologies and are, therefore, in high demand. As a result, supply with REEs is likely to be disrupted (the degree of depends on the REE) in the near future. The 17 REEs are divided into heavy and light REEs. Other critical elements besides REEs, identified by the European Commission, are also becoming less easily available. Although there is no deficiency in the earth's crust of rare earth oxides, the economic accessibility is limited. The increased demand for REEs, the decreasing export from China, and geopolitical concerns on availability contributed to the (re)opening of mines in Australia and the USA and other mines are slow to follow. As a result, short supply of particularly terbium, dysprosium, praseodymium, and neodymium is expected to be problematic for at least the short term, also because they cannot be substituted. Recycling REEs from electronic waste would be a solution, but so far there are hardly any established REE recycling methods. Decreasing the dependency on REEs, for example, by identifying possible replacements or increasing their efficient use, represents another possibility. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. METHODOLOGICAL ELEMENTS OF SITUATIONAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Tetyana KOVALCHUK

    2016-07-01

    Full Text Available The article deals with the investigation of theoretical and methodological principles of situational analysis. The necessity of situational analysis is proved in modern conditions. The notion “situational analysis” is determined. We have concluded that situational analysis is a continuous system study which purpose is to identify dangerous situation signs, to evaluate comprehensively such signs influenced by a system of objective and subjective factors, to search for motivated targeted actions used to eliminate adverse effects of the exposure of the system to the situation now and in the future and to develop the managerial actions needed to bring the system back to norm. It is developed a methodological approach to the situational analysis, its goal is substantiated, proved the expediency of diagnostic, evaluative and searching functions in the process of situational analysis. The basic methodological elements of the situational analysis are grounded. The substantiation of the principal methodological elements of system analysis will enable the analyst to develop adaptive methods able to take into account the peculiar features of a unique object which is a situation that has emerged in a complex system, to diagnose such situation and subject it to system and in-depth analysis, to identify risks opportunities, to make timely management decisions as required by a particular period.

  2. Recovery of trans-plutonium elements; Recuperation des elements transplutoniens

    Energy Technology Data Exchange (ETDEWEB)

    Espie, J.Y.; Poncet, B.; Simon, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1970-07-01

    The object of this work is to study the recovery of americium and curium from the fission-product solution obtained from the processing of irradiated fuel elements made of natural metallic uranium alloyed with aluminium, iron and silicon; these elements have been subjected to an average irradiation of 4000 MW days/ton in a gas-graphite type reactor having a thermal power of 3.7 MW/ton of uranium. The process used consists of 3 extraction cycles and one americium-curium separation: - 1) extraction cycle in 40 per cent TBP: extraction of actinides and lanthanides; elimination of fission products; - 2) extraction cycle in 8 per cent D2EHPA: decontamination from the fission products, decontamination of actinides from lanthanides; - 3) extraction cycle in 40 per cent TBP: separation of the complexing agent and concentration of the actinides; - 4) americium-curium separation by precipitation. (authors) [French] Cette etude a pour objet, la recuperation de l'americium et du curium de la solution de produits de fission provenant du traitement de combustibles irradies a base d'uranium naturel metallique allie a l'aluminium, le fer, et le silicium, et ayant subi une irradiation moyenne de 4000 MWj/t dans une pile du type graphite-gaz, dont la puissance thermique est de 3.7 MW/t d'uranium. Le procede utilise comprend 3 cycles d'extraction et une separation americium-curium: - 1. cycle d'extraction dans le TBP a 40 pour cent: extraction des actinides et des lanthanides, elimination des produits de fission; - 2. cycle d'extraction dans le D2EHPA a 8 pour cent: decontamination en produits de fission, decontamination des actinides en lanthanides; - 3. cycle d'extraction dans le TBP a 40 pour cent: separation du complexant et concentration des actinides; - 4. separation americium-curium par precipitation. (auteurs)

  3. A coupling procedure for modeling acoustic problems using finite elements and boundary elements

    OpenAIRE

    Coyette, J.; Vanderborck, G.; Steichen, W.

    1994-01-01

    Finite element (FEM) and boundary element (BEM) methods have been used for a long time for the numerical simulation of acoustic problems. The development presented in this paper deals with a general procedure for coupling acoustic finite elements with acoustic boundary elements in order to solve efficiently acoustic problems involving non homogeneous fluids. Emphasis is made on problems where finite elements are used for a confined (bounded) fluid while boundary elements are selected for an e...

  4. Multimodal transportation best practices and model element.

    Science.gov (United States)

    2014-06-01

    This report provides guidance in developing a multimodal transportation element of a local government comprehensive : plan. Two model elements were developed to address differences in statutory requirements for communities of different : sizes and pl...

  5. Natural wetland emissions of methylated trace elements

    NARCIS (Netherlands)

    Vriens, B.; Lenz, M.; Charlet, L.; Berg, M.; Winkel, L.H.E.

    2014-01-01

    Natural wetlands are well known for their significant methane emissions. However, trace element emissions via biomethylation and subsequent volatilization from pristine wetlands are virtually unstudied, even though wetlands constitute large reservoirs for trace elements. Here we show that the

  6. Analytic matrix elements with shifted correlated Gaussians

    DEFF Research Database (Denmark)

    Fedorov, D. V.

    2017-01-01

    Matrix elements between shifted correlated Gaussians of various potentials with several form-factors are calculated analytically. Analytic matrix elements are of importance for the correlated Gaussian method in quantum few-body physics....

  7. Microarray of programmable electrochemically active elements

    DEFF Research Database (Denmark)

    McCaskill, John; Maeke, Thomas; Straczek, Lukas

    Possible applications of the MICREAgents Dock, a two dimensional array of programmable electrochemically active elements, to Alife.......Possible applications of the MICREAgents Dock, a two dimensional array of programmable electrochemically active elements, to Alife....

  8. Solid finite elements through three decades

    OpenAIRE

    Venkatesh, DN; Shrinivasa, U

    1994-01-01

    conventionally, solid finite elements have been looked upon as just generalizations of two-dimensional finite elements. In this article we trace their development starting from the days of their inception. Keeping in tune with our perceptions on developing finite elements, without taking recourse to any extra variational techniques, we discuss a few of the techniques which have been applied to solid finite elements. Finally we critically examine our own work on formulating solid finite elemen...

  9. A unified architecture of transcriptional regulatory elements

    DEFF Research Database (Denmark)

    Andersson, Robin; Sandelin, Albin Gustav; Danko, Charles G.

    2015-01-01

    Gene expression is precisely controlled in time and space through the integration of signals that act at gene promoters and gene-distal enhancers. Classically, promoters and enhancers are considered separate classes of regulatory elements, often distinguished by histone modifications. However...... and enhancers are considered a single class of functional element, with a unified architecture for transcription initiation. The context of interacting regulatory elements and the surrounding sequences determine local transcriptional output as well as the enhancer and promoter activities of individual elements....

  10. An Improved Triangular Element With Drilling Rotations

    DEFF Research Database (Denmark)

    Damkilde, Lars; Grønne, Mikael

    2002-01-01

    by rotations in the corner nodes. Compared to Allman's plane element which was the first succesfull implementation of drilling rotations the proposed element has extra displacements in the mid-side nodes parallel to the element sides. The performance should therefore be better and closer to the LST...

  11. Element Cycles: An Environmental Chemistry Board Game

    Science.gov (United States)

    Pippins, Tracy; Anderson, Cody M.; Poindexter, Eric F.; Sultemeier, S. Whitney; Schultz, Linda D.

    2011-01-01

    "Element Cycles" is an activity designed to reinforce correlation of essential elements and their different forms in the ecosystem. Students are assigned essential elements to research as homework, then share results, and construct game boards with four ecosphere sections: geosphere (earth), hydrosphere (water), atmosphere (air), and biosphere…

  12. Elements from chlorine to calcium nuclear reactions

    CERN Document Server

    Kunz, Wunibald

    1968-01-01

    Nuclear Tables: Part II Nuclear Reactions, Volume 3: The Elements from Chlorine to Calcium contains tabulations of the nuclear reaction values of elements chlorine, argon, potassium, and calcium. These tabulations provide the calculated Q-values of the elements and their isotopes. This book will be of value to general chemistry researchers.

  13. Structural Variation of Element and Human Disease

    Directory of Open Access Journals (Sweden)

    Songmi Kim

    2016-09-01

    Full Text Available Transposable elements are one of major sources to cause genomic instability through various mechanisms including de novo insertion, insertion-mediated genomic deletion, and recombination-associated genomic deletion. Among them is Alu element which is the most abundant element, composing ~10% of the human genome. The element emerged in the primate genome 65 million years ago and has since propagated successfully in the human and non-human primate genomes. Alu element is a non-autonomous retrotransposon and therefore retrotransposed using L1-enzyme machinery. The 'master gene' model has been generally accepted to explain Alu element amplification in primate genomes. According to the model, different subfamilies of Alu elements are created by mutations on the master gene and most Alu elements are amplified from the hyperactive master genes. Alu element is frequently involved in genomic rearrangements in the human genome due to its abundance and sequence identity between them. The genomic rearrangements caused by Alu elements could lead to genetic disorders such as hereditary disease, blood disorder, and neurological disorder. In fact, Alu elements are associated with approximately 0.1% of human genetic disorders. The first part of this review discusses mechanisms of Alu amplification and diversity among different Alu subfamilies. The second part discusses the particular role of Alu elements in generating genomic rearrangements as well as human genetic disorders.

  14. 40 CFR 721.10068 - Elemental mercury.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Elemental mercury. 721.10068 Section... Substances § 721.10068 Elemental mercury. (a) Definitions. The definitions in § 721.3 apply to this section... elemental mercury (CAS. No. 7439-97-6) is subject to reporting under this section for the significant new...

  15. 36 CFR 230.35 - FLEP elements.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false FLEP elements. 230.35 Section... FORESTRY ASSISTANCE Forest Land Enhancement Program § 230.35 FLEP elements. (a) States may use FLEP funds... through the following elements: (1) Development and implementation of educational programs; (2) Resource...

  16. 19 CFR 149.3 - Data elements.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Data elements. 149.3 Section 149.3 Customs Duties... (CONTINUED) IMPORTER SECURITY FILING § 149.3 Data elements. (a) Shipments intended to be entered into the... provided for in paragraph (b) of this section, the following elements must be provided for each good listed...

  17. Stable propagation of 'selfish'genetic elements

    Indian Academy of Sciences (India)

    These elements exhibit a variety of `selfish' strategies to ensure their replication and propagation during the growth of their host cells. To establish long-term ... The 2 m plasmid of Saccharomyces cerevisiae and related yeast plasmids provide models for optimized eukaryotic selfish DNA elements. Selfish DNA elements ...

  18. Use of SCC in Prefabricated Concrete Elements

    DEFF Research Database (Denmark)

    Thrane, Lars Nyholm; Lauritsen, Ib

    2004-01-01

    This paper presents observations made on the use of self-compacting concrete for pre-cast elements at Byggebjerg Beton A/S during the last 3 years. The elements include L- and sandwich elements and are mainly produced for agriculture purposes. In general, the flow properties and air content...

  19. Production and properties of transuranium elements

    Energy Technology Data Exchange (ETDEWEB)

    Nagame, Y.; Hirata, M. [Japan Atomic Energy Agency, Tokai, Ibaraki (Japan)

    2011-07-01

    We summarize historical perspective of the transuranium elements, neptunium (Np) through lawrencium (Lr), and recent progress on production, and nuclear and chemical properties of these elements. Exotic decay properties of heavy nuclei are also introduced. Chemical properties of transuranium elements in aqueous and solid states are summarized based on the actinide concept. (orig.)

  20. Elements of Regolith Simulant's Cost Structure

    Science.gov (United States)

    Rickman, Douglas L.

    2009-01-01

    The cost of lunar regolith simulants is much higher than many users anticipate. After all, it is nothing more than broken rock. This class will discuss the elements which make up the cost structure for simulants. It will also consider which elements can be avoided under certain circumstances and which elements might be altered by the application of additional research and development.

  1. Elements of the cognitive universe

    Science.gov (United States)

    Topsøe, Flemming

    2017-06-01

    "The least biased inference, taking available information into account, is the one with maximum entropy". So we are taught by Jaynes. The many followers from a broad spectrum of the natural and social sciences point to the wisdom of this principle, the maximum entropy principle, MaxEnt. But "entropy" need not be tied only to classical entropy and thus to probabilistic thinking. In fact, the arguments found in Jaynes' writings and elsewhere can, as we shall attempt to demonstrate, profitably be revisited, elaborated and transformed to apply in a much more general abstract setting. The approach is based on game theoretical thinking. Philosophical considerations dealing with notions of cognition - basically truth and belief - lie behind. Quantitative elements are introduced via a concept of description effort. An interpretation of Tsallis Entropy is indicated.

  2. Zinc: a multipurpose trace element

    Energy Technology Data Exchange (ETDEWEB)

    Stefanidou, M.; Maravelias, C.; Dona, A.; Spiliopoulou, C. [University of Athens, Department of Forensic Medicine and Toxicology, Athens (Greece)

    2006-01-01

    Zinc (Zn) is one of the most important trace elements in the body and it is essential as a catalytic, structural and regulatory ion. It is involved in homeostasis, in immune responses, in oxidative stress, in apoptosis and in ageing. Zinc-binding proteins (metallothioneins, MTs), are protective in situations of stress and in situations of exposure to toxic metals, infections and low Zn nutrition. Metallothioneins play a key role in Zn-related cell homeostasis due to their high affinity for Zn, which is in turn relevant against oxidative stress and immune responses, including natural killer (NK) cell activity and ageing, since NK activity and Zn ion bioavailability decrease in ageing. Physiological supplementation of Zn in ageing and in age-related degenerative diseases corrects immune defects, reduces infection relapse and prevents ageing. Zinc is not stored in the body and excess intakes result in reduced absorption and increased excretion. Nevertheless, there are cases of acute and chronic Zn poisoning. (orig.)

  3. Elements of algebraic coding systems

    CERN Document Server

    Cardoso da Rocha, Jr, Valdemar

    2014-01-01

    Elements of Algebraic Coding Systems is an introductory text to algebraic coding theory. In the first chapter, you'll gain inside knowledge of coding fundamentals, which is essential for a deeper understanding of state-of-the-art coding systems. This book is a quick reference for those who are unfamiliar with this topic, as well as for use with specific applications such as cryptography and communication. Linear error-correcting block codes through elementary principles span eleven chapters of the text. Cyclic codes, some finite field algebra, Goppa codes, algebraic decoding algorithms, and applications in public-key cryptography and secret-key cryptography are discussed, including problems and solutions at the end of each chapter. Three appendices cover the Gilbert bound and some related derivations, a derivation of the Mac- Williams' identities based on the probability of undetected error, and two important tools for algebraic decoding-namely, the finite field Fourier transform and the Euclidean algorithm f...

  4. Mars Surface Tunnel Element Concept

    Science.gov (United States)

    Rucker, Michelle A.

    2016-01-01

    How crews get into or out of their ascent vehicle has profound implications for Mars surface architecture. Extravehicular Activity (EVA) hatches and Airlocks have the benefit of relatively low mass and high Technology Readiness Level (TRL), but waste consumables with a volume depressurization for every ingress/egress. Perhaps the biggest drawback to EVA hatches or Airlocks is that they make it difficult to keep Martian dust from being tracked back into the ascent vehicle, in violation of planetary protection protocols. Suit ports offer the promise of dust mitigation by keeping dusty suits outside the cabin, but require significant cabin real estate, are relatively high mass, and current operational concepts still require an EVA hatch to get the suits outside for the first EVA, and back inside after the final EVA. This is primarily because current designs don't provide enough structural support to protect the suits from ascent/descent loads or potential thruster plume impingement. For architectures involving more than one surface element-such as an ascent vehicle and a rover or surface habitat-a retractable tunnel is an attractive option. By pushing spacesuit don/doff and EVA operations to an element that remains on the surface, ascended vehicle mass and dust can be minimized. What's more, retractable tunnels provide operational flexibility by allowing surface assets to be re-configured or built up over time. Retractable tunnel functional requirements and design concepts being developed as part of the National Aeronautics and Space Administration's (NASA) Evolvable Mars Campaign (EMC) work will add a new ingress/egress option to the surface architecture trade space.

  5. Studying accelerometers with capacitive sensing elements

    Directory of Open Access Journals (Sweden)

    Ágoston Katalin

    2011-12-01

    Full Text Available This paper presents types and operating mode of vibration sensors. Differential capacitor sensing elements are often used in integrated accelerometers. It will be investigate the structure and transfer function of the seismic mass type sensing element. The article presents how the piezoelectric sensing element works and compares with capacitor sensing element and how can be modeled with an electronic circuit and Simulink models. The transfer functions of the capacitor sensing element models are studied in Matlab and the results are presented.

  6. Synthesis of superheavy elements by cold fusion

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, S. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Frankfurt Univ. (Germany). Inst. fuer Kernphysik

    2011-07-01

    The new elements from Z = 107 to 112 were synthesized in cold fusion reactions based on targets of lead and bismuth. The principle physical concepts are presented which led to the application of this reaction type in search experiments for new elements. Described are the technical developments from early mechanical devices to experiments with recoil separators. An overview is given of present experiments which use cold fusion for systematic studies and synthesis of new isotopes. Perspectives are also presented for the application of cold fusion reactions in synthesis of elements beyond element 113, the so far heaviest element produced in a cold fusion reaction. Further, the transition of hot fusion to cold fusion is pointed out, which occurs in reactions for synthesis of elements near Z = 126 using actinide targets and beams of neutron rich isotopes of elements from iron to germanium. (orig.)

  7. Pump element for a tube pump

    DEFF Research Database (Denmark)

    2011-01-01

    The invention relates to a tube pump comprising a tube and a pump element inserted in the tube, where the pump element comprises a rod element and a first and a second non-return valve member positioned a distance apart on the rod element. The valve members are oriented in the same direction...... portion acts to alternately close and open the valve members thereby generating a fluid flow through the tube. The invention further relates to a pump element comprising at least two non-return valve members connected by a rod element, and for insertion in an at least partly flexible tube in such tube...... pump as mentioned above, thereby acting to generate a fluid flow through the tube upon repeated deformation of the tube between the two valve members. The pump element may comprise a connecting part for coupling to another tube and may comprise a sealing part establishing a fluid tight connection...

  8. Superheavy element chemistry at GARIS

    Directory of Open Access Journals (Sweden)

    Haba Hiromitsu

    2016-01-01

    Full Text Available A gas-jet transport system has been installed to the RIKEN GAs-filled Recoil Ion Separator, GARIS to start up SuperHeavy Element (SHE chemistry. This system is a promising approach for exploring new frontiers in SHE chemistry: background radioactivities from unwanted by-products are suppressed, a high gas-jet transport yield is achieved, and new chemical reactions can be investigated. Useful radioisotopes of 261Rfa,b, 262Db, and 265Sga,b for chemical studies were produced in the reactions of 248Cm(18O,5n261Rfa,b, 248Cm(19F,5n262Db, and 248Cm(22Ne,5n265Sga,b, respectively. They were successfully extracted to a chemistry laboratory by the gas-jet method. Production and decay properties of 261Rfa,b, 262Db, and 265Sga,b were investigated in detail with the rotating wheel apparatus for α- and spontaneous fission spectrometry. Present status and perspectives of the SHE chemistry at GARIS are also briefly presented.

  9. Recycling of Rare Earth Elements

    Science.gov (United States)

    Lorenz, Tom; Bertau, Martin

    2017-01-01

    Any development of an effective process for rare earth (RE) recycling has become more and more challenging, especially in recent years. Since 2011, when commodity prices of REs had met their all-time maximum, prices have dropped rapidly by more than 90 %. An economic process able to offset these fluctuations has to take unconventional methods into account beside well-known strategies like acid/basic leaching or solvent extraction. The solid-state chlorination provides such an unconventional method for mobilizing RE elements from waste streams. Instead of hydrochloric acid this kind of chlorination decomposes NH4Cl thermally to release up to 400 °C hot HCl gas. After cooling the resulting solid metal chlorides may be easily dissolved in pH-adjusted water. Without producing strongly acidic wastes and with NH4Cl as cheap source for hydrogen chloride, solid-state chlorination provides various advantages in terms of costs and disposal. In the course of the SepSELSA project this method was examined, adjusted and optimized for RE recycling from fluorescent lamp scraps as well as Fe14Nd2B magnets. Thereby many surprising influences and trends required various analytic methods to examine the reasons and special mechanisms behind them.

  10. FEBio: finite elements for biomechanics.

    Science.gov (United States)

    Maas, Steve A; Ellis, Benjamin J; Ateshian, Gerard A; Weiss, Jeffrey A

    2012-01-01

    In the field of computational biomechanics, investigators have primarily used commercial software that is neither geared toward biological applications nor sufficiently flexible to follow the latest developments in the field. This lack of a tailored software environment has hampered research progress, as well as dissemination of models and results. To address these issues, we developed the FEBio software suite (http://mrl.sci.utah.edu/software/febio), a nonlinear implicit finite element (FE) framework, designed specifically for analysis in computational solid biomechanics. This paper provides an overview of the theoretical basis of FEBio and its main features. FEBio offers modeling scenarios, constitutive models, and boundary conditions, which are relevant to numerous applications in biomechanics. The open-source FEBio software is written in C++, with particular attention to scalar and parallel performance on modern computer architectures. Software verification is a large part of the development and maintenance of FEBio, and to demonstrate the general approach, the description and results of several problems from the FEBio Verification Suite are presented and compared to analytical solutions or results from other established and verified FE codes. An additional simulation is described that illustrates the application of FEBio to a research problem in biomechanics. Together with the pre- and postprocessing software PREVIEW and POSTVIEW, FEBio provides a tailored solution for research and development in computational biomechanics.

  11. Weak matrix elements of kaons

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, C. (California Univ., Santa Barbara, CA (USA). Inst. for Theoretical Physics); Soni, A. (Brookhaven National Lab., Upton, NY (USA))

    1989-01-01

    We present results from the Wilson fermion part of the Grand Challenge'' weak matrix element project. A new procedure for correcting the chiral behavior of {Beta}{sub LL}{sup sd}, the K{sup 0}-{bar K}{sup 0} {Beta} parameter,'' is proposed and applied. On our largest lattice (24{sup 3} {times} 40 at {beta} = 6.0), we get {Beta}{sub LL}{sup sd} = .86 {plus minus} .11 {plus minus} .05, where the first error is statistical and the second is a measure of the systematic errors due to the procedure and to related finite-size effects. Results for the direct K{sup +} {yields} {pi}{sup +}{pi}{sup 0} amplitude are also presented. There is some evidence for higher order chiral effects which may make these results compatible both with experiment and with the {Beta}{sub LL}{sup sd} computation. The status of the direct K{sub s}{sup 0} {yields} {pi} {sup +} {pi}{sup {minus}} {Delta}I = 1/2 amplitude is then discussed. 11 refs., 6 figs., 1 tab.

  12. Daimonic elements in early trauma.

    Science.gov (United States)

    Kalsched, Donald E

    2003-04-01

    This paper explores some of the 'daimonic' elements of unconscious mentation that emerge both in dreams and in the transference/countertransference field with early-trauma patients and illustrates these with an extended clinical example. An archaic and typical (archetypal) 'trauma complex' is articulated (with diagram) as a bi-polar structure consisting of divine child protected and/or persecuted by an inner 'guardian angel'. Sources of this structure and its mythological inner objects are traced to trauma at the stage of what Winnicott calls 'unintegration' and to flooding by disintegration anxiety at a time before nascent ego-structure has formed. In an extended case example, the author shows how the patient's traumatized innocence and desire for a new start, thwarted by self-attacking defences, pulls him into playing the inflated role of her guardian angel, leading to re-traumatization in the transference. Working through is seen as the necessary disillusionment and humanization of these daimonic structures as they are projected, suffered, and transmuted by the analytic partners in the stormy process of psychotherapy.

  13. Functions over RDF Language Elements

    Science.gov (United States)

    Schandl, Bernhard

    RDF data are usually accessed using one of two methods: either, graphs are rendered in forms perceivable by human users (e.g., in tabular or in graphical form), which are difficult to handle for large data sets. Alternatively, query languages like SPARQL provide means to express information needs in structured form; hence they are targeted towards developers and experts. Inspired by the concept of spreadsheet tools, where users can perform relatively complex calculations by splitting formulas and values across multiple cells, we have investigated mechanisms that allow us to access RDF graphs in a more intuitive and manageable, yet formally grounded manner. In this paper, we make three contributions towards this direction. First, we present RDFunctions, an algebra that consists of mappings between sets of RDF language elements (URIs, blank nodes, and literals) under consideration of the triples contained in a background graph. Second, we define a syntax for expressing RDFunctions, which can be edited, parsed and evaluated. Third, we discuss Tripcel, an implementation of RDFunctions using a spreadsheet metaphor. Using this tool, users can easily edit and execute function expressions and perform analysis tasks on the data stored in an RDF graph.

  14. MEET: motif elements estimation toolkit.

    Science.gov (United States)

    Pairó, Erola; Maynou, Joan; Vallverdú, Montserrat; Caminal, Pere; Marco, Santiago; Perera, Alexandre

    2011-01-01

    MEET is an R package that integrates a set of algorithms for the detection of transcription factor binding sites (TFBS). The MEET R package includes five motif searching algorithms: MEME/MAST(Multiple Expectation-Maximization for Motif Elicitation), Q-residuals, MDscan (Motif Discovery scan), ITEME (Information Theory Elements for Motif Estimation) and MATCH. In addition MEET allows the user to work with different alignment algorithms: MUSCLE (Multiple Sequence Comparison by Log-Expectation), ClustalW and MEME. The package can work in two modes, training and detection. The training mode allows the user to choose the best parameters of a detector. Once the parameters are chosen, the detection mode allows to analyze a genome looking for binding sites. Both modes can combine the different alignment and detection methods, offering multiple possibilities. Combining the alignments and the detection algorithms makes possible the comparison between detection models at the same level, without having to care about the differences produced during the alignment process. The MEET R package can be downloaded from http://sisbio.recerca.upc.edu/R/MEET_1.0. tar.gz.

  15. Why and how of finite elements

    Energy Technology Data Exchange (ETDEWEB)

    Ackroyd, R.T. (UKAEA Risley Nuclear Power Development Establishment)

    1981-01-01

    The development of the finite element method is traced to show how ideas from structural and fluid mechanics, the calculus of variations, functional analysis and the calculus of finite differences have been forged to provide a tool which minimizes the mismatch between the behaviour of a continuous system and that of a discrete model of the system assembled from finite elements. Geometrical flexibility of the model is achieved by the use of polygonal and curved elements. The behaviour of any point of an element is described in terms of its behaviour at discrete points or nodes of the element. In treating neutron transport the finite element method can be applied to phase-space, or the spatial dependence can be treated by the use of finite elements in conjuction with expansions in orthogonal functions for the directional dependence. The maximum principle for the second-order even-parity Boltzmann equations is used to demonstrate the precision and flexibility of the finite element method by solving the problems of a doglegged duct in a shield and a cylindrical fuel element in a square lattice cell. The geometrical interpretation of the boundary-free maximum principle with the aid of a suitable Hilbert space then leads to completely boundary-free weighted residual or Galerkin schemes for both the first- and second-order forms of the Boltzmann equation. Imposing essential boundary conditions leads to classical schemes, a sketch of finite element treatments of the multigroup Boltzmann equation is given.

  16. Visualization of higher order finite elements.

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, David C.; Pebay, Philippe Pierre; Crawford, Richard H.; Khardekar, Rahul Vinay

    2004-04-01

    Finite element meshes are used to approximate the solution to some differential equation when no exact solution exists. A finite element mesh consists of many small (but finite, not infinitesimal or differential) regions of space that partition the problem domain, {Omega}. Each region, or element, or cell has an associated polynomial map, {Phi}, that converts the coordinates of any point, x = ( x y z ), in the element into another value, f(x), that is an approximate solution to the differential equation, as in Figure 1(a). This representation works quite well for axis-aligned regions of space, but when there are curved boundaries on the problem domain, {Omega}, it becomes algorithmically much more difficult to define {Phi} in terms of x. Rather, we define an archetypal element in a new coordinate space, r = ( r s t ), which has a simple, axis-aligned boundary (see Figure 1(b)) and place two maps onto our archetypal element:

  17. Equilibrium-Based Nonhomogeneous Anisotropic Beam Element

    DEFF Research Database (Denmark)

    Krenk, Steen; Couturier, Philippe

    2017-01-01

    The stiffness matrix and the nodal forces associated with distributed loads are obtained for a nonhomogeneous anisotropic elastic beam element by the use of complementary energy. The element flexibility matrix is obtained by integrating the complementary-energy density corresponding to six beam...... equilibrium states, and then inverted and expanded to provide the element-stiffness matrix. Distributed element loads are represented via corresponding internal-force distributions in local equilibrium with the loads. The element formulation does not depend on assumed shape functions and can, in principle......, include any variation of cross-sectional properties and load variation, provided that these are integrated with sufficient accuracy in the process. The ability to represent variable cross-sectional properties, coupling from anisotropic materials, and distributed element loads is illustrated by numerical...

  18. Elements as a metaphor of personality

    OpenAIRE

    Abramčuk, Filip

    2009-01-01

    The project deals theoretically and empirically with a mechanism the metaphor of four elements works used by personality description. It is based on the theory of conceptual metaphor, on the categorization and the theory of prototypes and on the theory of folk models. Empirically it is devoted to these research goals: 1. To find out what meaning are the strongest atributed to each element and to map systematically their semantic space. 2. To contribute to the operationalization of the element...

  19. Noncoding Elements: Evolution and Epigenetic Regulation

    KAUST Repository

    Seridi, Loqmane

    2016-03-09

    When the human genome project was completed, it revealed a surprising result. 98% of the genome did not code for protein of which more than 50% are repeats— later known as ”Junk DNA”. However, comparative genomics unveiled that many noncoding elements are evolutionarily constrained; thus luckily to have a role in genome stability and regulation. Though, their exact functions remained largely unknown. Several large international consortia such as the Functional Annotation of Mammalian Genomes (FANTOM) and the Encyclopedia of DNA Elements (ENCODE) were set to understand the structure and the regulation of the genome. Specifically, these endeavors aim to measure and reveal the transcribed components and functional elements of the genome. One of the most the striking findings of these efforts is that most of the genome is transcribed, including non-conserved noncoding elements and repeat elements. Specifically, we investigated the evolution and epigenetic properties of noncoding elements. 1. We compared genomes of evolutionarily distant species and showed the ubiquity of constrained noncoding elements in metazoa. 2. By integrating multi-omic data (such as transcriptome, nucleosome profiling, histone modifications), I conducted a comprehensive analysis of epigenetic properties (chromatin states) of conserved noncoding elements in insects. We showed that those elements have distinct and protective sequence features, undergo dynamic epigenetic regulation, and appear to be associated with the structural components of the chromatin, replication origins, and nuclear matrix. 3. I focused on the relationship between enhancers and repetitive elements. Using Cap Analysis of Gene Expression (CAGE) and RNASeq, I compiled a full catalog of active enhancers (a class of noncoding elements) during myogenesis of human primary cells of healthy donors and donors affected by Duchenne muscular dystrophy (DMD). Comparing the two time-courses, a significant change in the epigenetic

  20. Nonconforming tetrahedral mixed finite elements for elasticity

    OpenAIRE

    Arnold, Douglas N.; Awanou, Gerard; Winther, Ragnar

    2012-01-01

    This paper presents a nonconforming finite element approximation of the space of symmetric tensors with square integrable divergence, on tetrahedral meshes. Used for stress approximation together with the full space of piecewise linear vector fields for displacement, this gives a stable mixed finite element method which is shown to be linearly convergent for both the stress and displacement, and which is significantly simpler than any stable conforming mixed finite element method. The method ...

  1. Domain decomposition methods for mortar finite elements

    Energy Technology Data Exchange (ETDEWEB)

    Widlund, O.

    1996-12-31

    In the last few years, domain decomposition methods, previously developed and tested for standard finite element methods and elliptic problems, have been extended and modified to work for mortar and other nonconforming finite element methods. A survey will be given of work carried out jointly with Yves Achdou, Mario Casarin, Maksymilian Dryja and Yvon Maday. Results on the p- and h-p-version finite elements will also be discussed.

  2. Integrating Environmentally Responsive Elements in Buildings

    DEFF Research Database (Denmark)

    Heiselberg, Per; Andresen, Inger; Perino, Marco

    2006-01-01

    Significant improvement have been achieved on efficiency improvements of specific building elements like the building envelope and building equipment and services and whilst most building elements still offer opportunities for efficiency improvements, the greatest future potential lie...... with technologies that promote the integration of responsive building elements and building services in integrated building concepts. In order to address some of these issues an international research effort, IEA-ECBCS Annex 44 has been initiated. The paper especially presents the annex activities regarding...

  3. The Mathematics of Finite Elements and Applications

    Science.gov (United States)

    1993-04-30

    adaptive mesh refinement ( AMR ) are nowadays two of the challenging issues in the finite element method (FEM). In this paper a methodology for deriving AMR ...parameters and that of the element refinement parameter are obtained for each case. Finally, the efficiency of the two AMR methodologies studied is...operators approximated. Appropriate error bounds are established. A K MOHAMMED, M H BALUCH and S T GOMAA Finite element modelling of deep beams using a

  4. Superheavy Elements Challenge Experimental and Theoretical Chemistry

    CERN Document Server

    Zvára, I

    2003-01-01

    When reflecting on the story of superheavy elements, the an experimenter, acknowledges the role, which the predictions of nuclear and chemical theories have played in ongoing studies. Today, the problems of major interest for experimental chemistry are the studies of elements 112 and 114 including their chemical identification. Advanced quantum chemistry calculations of atoms and molecules would be of much help. First experiments with element 112 evidence that the metal is much more volatile and inert than mercury.

  5. Defining and testing a granular continuum element

    OpenAIRE

    Rycroft, Chris H.; Kamrin, Ken; Bazant, Martin Z.

    2008-01-01

    Continuum mechanics relies on the fundamental notion of a mesoscopic volume "element" in which properties averaged over discrete particles obey deterministic relationships. Recent work on granular materials suggests a continuum law may be inapplicable, revealing inhomogeneities at the particle level, such as force chains and slow cage breaking. Here, we analyze large-scale Discrete-Element Method (DEM) simulations of different granular flows and show that a "granular element" can indeed ...

  6. Benchmarking the QUAD4/TRIA3 element

    Science.gov (United States)

    Pitrof, Stephen M.; Venkayya, Vipperla B.

    1993-01-01

    The QUAD4 and TRIA3 elements are the primary plate/shell elements in NASTRAN. These elements enable the user to analyze thin plate/shell structures for membrane, bending and shear phenomena. They are also very new elements in the NASTRAN library. These elements are extremely versatile and constitute a substantially enhanced analysis capability in NASTRAN. However, with the versatility comes the burden of understanding a myriad of modeling implications and their effect on accuracy and analysis quality. The validity of many aspects of these elements were established through a series of benchmark problem results and comparison with those available in the literature and obtained from other programs like MSC/NASTRAN and CSAR/NASTRAN. Never-the-less such a comparison is never complete because of the new and creative use of these elements in complex modeling situations. One of the important features of QUAD4 and TRIA3 elements is the offset capability which allows the midsurface of the plate to be noncoincident with the surface of the grid points. None of the previous elements, with the exception of bar (beam), has this capability. The offset capability played a crucial role in the design of QUAD4 and TRIA3 elements. It allowed modeling layered composites, laminated plates and sandwich plates with the metal and composite face sheets. Even though the basic implementation of the offset capability is found to be sound in the previous applications, there is some uncertainty in relatively simple applications. The main purpose of this paper is to test the integrity of the offset capability and provide guidelines for its effective use. For the purpose of simplicity, references in this paper to the QUAD4 element will also include the TRIA3 element.

  7. Isotopic Compositions of the Elements 1997

    Science.gov (United States)

    Rosman, K. J. R.; Taylor, P. D. P.

    1998-11-01

    The Commission's Subcommittee for the Isotopic Composition of the Elements has carried out its biennial review of isotopic compositions, as determined by mass spectrometry and other relevant methods. This involves a critical evaluation of the published literature, element by element, and forms the basis of the Table of Isotopic Compositions of the Elements as Determined by Mass Spectrometry presented here. New guidelines have been used to arrive at the uncertainties on the isotopic abundances and there are numerous changes to the table since it was last published in 1991. Atomic Weights calculated from this table are consistent with Ar(E) values listed in the Table of Standard Atomic Weights 1997.

  8. Spectral analysis method for detecting an element

    Science.gov (United States)

    Blackwood, Larry G [Idaho Falls, ID; Edwards, Andrew J [Idaho Falls, ID; Jewell, James K [Idaho Falls, ID; Reber, Edward L [Idaho Falls, ID; Seabury, Edward H [Idaho Falls, ID

    2008-02-12

    A method for detecting an element is described and which includes the steps of providing a gamma-ray spectrum which has a region of interest which corresponds with a small amount of an element to be detected; providing nonparametric assumptions about a shape of the gamma-ray spectrum in the region of interest, and which would indicate the presence of the element to be detected; and applying a statistical test to the shape of the gamma-ray spectrum based upon the nonparametric assumptions to detect the small amount of the element to be detected.

  9. Books and monographs on finite element technology

    Science.gov (United States)

    Noor, A. K.

    1985-01-01

    The present paper proviees a listing of all of the English books and some of the foreign books on finite element technology, taking into account also a list of the conference proceedings devoted solely to finite elements. The references are divided into categories. Attention is given to fundamentals, mathematical foundations, structural and solid mechanics applications, fluid mechanics applications, other applied science and engineering applications, computer implementation and software systems, computational and modeling aspects, special topics, boundary element methods, proceedings of symmposia and conferences on finite element technology, bibliographies, handbooks, and historical accounts.

  10. A first course in finite elements

    CERN Document Server

    Fish, Jacob

    2007-01-01

    Developed from the authors, combined total of 50 years undergraduate and graduate teaching experience, this book presents the finite element method formulated as a general-purpose numerical procedure for solving engineering problems governed by partial differential equations.  Focusing on the formulation and application of the finite element method through the integration of finite element theory, code development, and software application, the book is both introductory and self-contained, as well as being a hands-on experience for any student. This authoritative text on Finite Elements:Adopts

  11. Time elements. [for transformations in satellite equations

    Science.gov (United States)

    Nacozy, P. E.

    1974-01-01

    Time elements are introduced for use with Sundman time transformations of the type dt = r(alpha)ds for satellite equations of motion. Two time elements are given, one providing maximum accuracy for alpha = 1, the other for alpha = 2. Time elements and time transformations reduce local truncation error and Liapunov (in track) instability, and provide analytical step size control. Numerical results show accuracy improvements of more than one order of magnitude when time elements are employed with time transformations in the numerical integration of the satellite equations, compared with using time transformations alone.

  12. Nonconforming finite element methods on quadrilateral meshes

    Science.gov (United States)

    Hu, Jun; Zhang, ShangYou

    2013-12-01

    It is well-known that it is comparatively difficult to design nonconforming finite elements on quadrilateral meshes by using Gauss-Legendre points on each edge of triangulations. One reason lies in that these degrees of freedom associated to these Gauss-Legendre points are not all linearly independent for usual expected polynomial spaces, which explains why only several lower order nonconforming quadrilateral finite elements can be found in literature. The present paper proposes two families of nonconforming finite elements of any odd order and one family of nonconforming finite elements of any even order on quadrilateral meshes. Degrees of freedom are given for these elements, which are proved to be well-defined for their corresponding shape function spaces in a unifying way. These elements generalize three lower order nonconforming finite elements on quadrilaterals to any order. In addition, these nonconforming finite element spaces are shown to be full spaces which is somehow not discussed for nonconforming finite elements in literature before.

  13. Elemental Analysis and Biological Activities of Chrysophyllum ...

    African Journals Online (AJOL)

    The present study was performed to estimate elementals and to determine bioactivities namely anticariogenic, antioxidant, pancreatic lipase inhibitory and cytotoxic activity of Chrysophyllum roxburghii leaves. Elemental analysis revealed that calcium and manganese were present in high concentration among principal and ...

  14. ELEMENTAL ANALYSIS OF THE LEAVES OF VERNONIA ...

    African Journals Online (AJOL)

    Elemental analysis of the leaves of Vernonia amygdalina Del., revealed adequate concentrations of some elements, such as iron (1500+111 ppm) and calcium 10100+895 ppm) that are believed to be essential for normal growth. The plant was evaluated in relation to tissue damage, in sixteen male rats (Wistar strains) with ...

  15. Simultaneous Multi-Element Electrothermal Atomic Absorption ...

    African Journals Online (AJOL)

    In the experiments simultaneous determination of 18 elements was performed in the mixed solutions at the mg L–1 to μg L–1 level, within 4–4.5 orders of magnitude linear concentration range. About 1–2 min was needed for the measurement and calculation. Limits of detection (LOD) for individual elements were 1.5–2 ...

  16. Conceptual problems with remote element synthesis

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 109; Issue 1 ... Element synthesis; isotopes; solar system; meteorites; planets. Abstract. The notion of remote element synthesis has recently been modified to explain the presence of nucleogenetic isotopic anomalies and decay products of short-lived nuclides by ...

  17. Contact fatigue in rolling-element bearings

    CSIR Research Space (South Africa)

    Fernandes, PJL

    1997-06-01

    Full Text Available Surface contact fatigue is a common cause of failure in rolling-element bearings. The extent of damage observed depends on the contact loads, the curvature of the rolling elements, and the relative motion between the contacting surfaces...

  18. DIFFERENT ELEMENT METHODS IN ENGINEERING PRACTICE

    African Journals Online (AJOL)

    2012-11-03

    Nov 3, 2012 ... (or system) in the sense that the behavior at discrete number of ... squares method can be used in deriving the element equation. Whichever formulation approach is used, the result- ing element equation are solved using appropriate ma- trix solvers .... symmetric stiffness matrix, but also the non-essential.

  19. Elements of Inclusion: Findings from the Field

    Science.gov (United States)

    McMaster, Christopher

    2014-01-01

    The Ministry of Education has set the target of 100% of New Zealand schools to be "mostly" inclusive by 2014. But what are the essential elements of inclusion? This paper explores essential core elements that allow inclusion to flourish. Based on an extensive time in the field as part of a year-long doctoral research project, these…

  20. Just-in-time elements and benefits

    CERN Document Server

    García-Alcaraz, Jorge Luis

    2016-01-01

    This book reports the elements required for implementing Just in Time (JIT) technique in companies. The main reasons for low implementation processes and the main benefits from the successful implementation of them are highlighted in this book. Structural equation models are presented to help identify the essential elements in JIT.

  1. Elemental Etymology: What's in a Name?

    Science.gov (United States)

    Ball, David W.

    1985-01-01

    Examines the origin of the names (or etymologies) of the chemical elements. Includes tables listing elements: (1) with names of obscure origin; (2) named for colors; (3) named after real or mythical people; (4) named after places; (5) named after heavenly bodies; and (6) having names of miscellaneous origin. (JN)

  2. MODERATOR ELEMENTS FOR UNIFORM POWER NUCLEAR REACTOR

    Science.gov (United States)

    Balent, R.

    1963-03-12

    This patent describes a method of obtaining a flatter flux and more uniform power generation across the core of a nuclear reactor. The method comprises using moderator elements having differing moderating strength. The elements have an increasing amount of the better moderating material as a function of radial and/or axial distance from the reactor core center. (AEC)

  3. 47 CFR 97.505 - Element credit.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Element credit. 97.505 Section 97.505... SERVICE Qualifying Examination Systems § 97.505 Element credit. (a) The administering VEs must give credit.... (b) No examination credit, except as herein provided, shall be allowed on the basis of holding or...

  4. Heavy Metals and Related Trace Elements.

    Science.gov (United States)

    Leland, Harry V.; And Others

    1978-01-01

    Presents a literature review of heavy metals and related trace elements in the environment, covering publications of 1976-77. This review includes: (1) trace treatment in natural water and in sediments; and (2) bioaccumulation and toxicity of trace elements. A list of 466 references is presented. (HM)

  5. Det pædagogiske element

    DEFF Research Database (Denmark)

    Thomsen, Viggo Ernst; Skipper-Jørgensen, Anette Maren

    2010-01-01

    Om det pædagogiske element i læreruddannelsen på matematik aldersspecialisering mod begynder- og mellemtrin......Om det pædagogiske element i læreruddannelsen på matematik aldersspecialisering mod begynder- og mellemtrin...

  6. New orbital elements for 5 double stars

    Directory of Open Access Journals (Sweden)

    Olević D.

    2001-01-01

    Full Text Available In this paper are presented recalculated elliptical and Thiel-Innes orbitatal elements for the following double stars: WDS05255-0033, WDS12272+2701, WDS 13336+2944 and WDS 21031+0132 (two versions. The elements of the pair WDS 06074+2640 = McA 25 are calculated for the first time.

  7. Trace element analysis of soy sauce

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Michio; Haruyama, Yoichi; Saito, Manabu [Kyoto Prefectural Univ. (Japan)

    1994-07-01

    Trace elements in soy sauce have been measured by means of in-air PIXE. Six kinds of trace elements were detected, such as Mu, Fe, Ni, Zn, Cu and Br. Concentrations of Mn, Fe, Zn and Br which were observed in all samples, have been determined. Each analyzed sample contained considerable amount of bromine about 160 ppm. (author).

  8. Damper mechanism for nuclear reactor control elements

    Science.gov (United States)

    Taft, William Elwood

    1976-01-01

    A damper mechanism which provides a nuclear reactor control element decelerating function at the end of the scram stroke. The total damping function is produced by the combination of two assemblies, which operate in sequence. First, a tapered dashram assembly decelerates the control element to a lower velocity, after which a spring hydraulic damper assembly takes over to complete the final damping.

  9. Finite element bending behaviour of discretely delaminated ...

    African Journals Online (AJOL)

    user

    for large deformations in curved panels including full cylinders by finite element method. Acharyya et al. 2008 used a finite element method for the study of bending behaviour of partially delaminated shallow cylindrical composite shells subjected to uniformly distributed load with various practical boundary conditions.

  10. Non-linear finite element modeling

    DEFF Research Database (Denmark)

    Mikkelsen, Lars Pilgaard

    The note is written for courses in "Non-linear finite element method". The note has been used by the author teaching non-linear finite element modeling at Civil Engineering at Aalborg University, Computational Mechanics at Aalborg University Esbjerg, Structural Engineering at the University...

  11. Phytochemical screening, proximate and elemental analysis of ...

    African Journals Online (AJOL)

    Citrus sinensis was screened for its phytochemical composition and was evaluated for the proximate and elemental analysis. The phytochemical analysis indicated the presence of reducing sugar, saponins, cardiac glycosides, tannins and flavonoids. The elemental analysis indicated the presence of the following mineral ...

  12. Horizontal infiltration and trace element measurements for ...

    African Journals Online (AJOL)

    Concentration data for twenty-one elements ( Sb, Ba, Ce, Co, Cr, Cs, Eu, Hf, Fe, La, Lu, Nd, K, Rb, Sc, Na, Ta, Th, U, Yb, Zn) were also determined for the three soils. The study revealed that although the mineralogy of the soils appeared similar based on their mean elemental compositions, the Fadama soils showed high ...

  13. Nonconforming finite elements and the Cascade iteration

    NARCIS (Netherlands)

    Stevenson, R.

    1999-01-01

    We derive sucient conditions under which the Cascade iteration applied to nonconforming nite element discretizations yields an optimal solver. Key ingredients are optimal error estimates of such discretizations, which we therefore study in detail. We derive a new, ecient modied Morley nite element

  14. PROXIMATE AND ELEMENTAL COMPOSITION OF WHITE GRUBS

    African Journals Online (AJOL)

    DR. AMINU

    PROXIMATE AND ELEMENTAL COMPOSITION OF WHITE GRUBS. 1 Alhassan, A. J. 1M .S. Sule, 1J. ... ABSTRACT. This study determined the proximate and mineral element composition of whole white grubs using standard methods of analysis. Proximate ... days, before pulverized to powder and kept in plastic container.

  15. 42 CFR 51c.403 - Project elements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Project elements. 51c.403 Section 51c.403 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS GRANTS FOR COMMUNITY HEALTH SERVICES Grants for Operating Community Health Projects § 51c.403 Project elements. A project for the...

  16. 42 CFR 56.603 - Project elements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Project elements. 56.603 Section 56.603 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS GRANTS FOR MIGRANT HEALTH SERVICES Grants for Operating Migrant Health Programs § 56.603 Project elements. A project for operating a...

  17. 42 CFR 51c.203 - Project elements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Project elements. 51c.203 Section 51c.203 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS GRANTS FOR COMMUNITY HEALTH SERVICES Grants for Planning and Developing Community Health Centers § 51c.203 Project elements. A project...

  18. 42 CFR 51c.504 - Project elements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Project elements. 51c.504 Section 51c.504 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS GRANTS FOR COMMUNITY HEALTH SERVICES Acquisition and Modernization of Existing Buildings § 51c.504 Project elements. (a) General...

  19. 42 CFR 56.503 - Project elements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Project elements. 56.503 Section 56.503 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS GRANTS FOR MIGRANT HEALTH SERVICES Grants for Planning and Developing Migrant Health Programs § 56.503 Project elements. A project...

  20. 42 CFR 56.703 - Project elements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Project elements. 56.703 Section 56.703 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS GRANTS FOR MIGRANT HEALTH SERVICES Grants for Technical Assistance § 56.703 Project elements. A project for the provision of...

  1. 42 CFR 56.403 - Project elements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Project elements. 56.403 Section 56.403 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS GRANTS FOR MIGRANT HEALTH SERVICES Grants for Operating Migrant Health Entities § 56.403 Project elements. A project for the...

  2. 42 CFR 56.203 - Project elements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Project elements. 56.203 Section 56.203 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS GRANTS FOR MIGRANT HEALTH SERVICES Grants for Planning and Developing Migrant Health Centers § 56.203 Project elements. A project for...

  3. 47 CFR 10.420 - Message elements.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Message elements. 10.420 Section 10.420... Requirements § 10.420 Message elements. A CMAS Alert Message processed by a Participating CMS Provider shall include five mandatory CAP elements—Event Type; Area Affected; Recommended Action; Expiration Time (with...

  4. 16 CFR 314.4 - Elements.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Elements. 314.4 Section 314.4 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS STANDARDS FOR SAFEGUARDING CUSTOMER INFORMATION § 314.4 Elements. In order to develop, implement, and maintain your information...

  5. Nutritional composition, antinutritional factors and elemental ...

    African Journals Online (AJOL)

    Nutritional composition, antinutritional factors and elemental analysis of Nymphaea lotus (water lily). RSU Wasagu, M Lawal, LG Galadima, AA Aliero. Abstract. The study is aimed at evaluating nutritional composition, antinutritional factors and elemental analysis of three parts (roots sample RS, seed sample SS and leave ...

  6. The New Element Curium (Atomic Number 96)

    Science.gov (United States)

    Seaborg, G. T.; James, R. A.; Ghiorso, A.

    1948-01-01

    Two isotopes of the element with atomic number 96 have been produced by the helium-ion bombardment of plutonium. The name curium, symbol Cm, is proposed for element 96. The chemical experiments indicate that the most stable oxidation state of curium is the III state.

  7. Endangered Elements of the Periodic Table

    Indian Academy of Sciences (India)

    Their analysis revealedthat 44 elements are facing limited supply, or are under thethreat of becoming scarce or inaccessible. These includes allof the rare earth elements, as well as zinc, gallium, germanium,helium, silver, and even phosphorus. The Royal Societyof Chemistry has also published a color-coded periodictable, ...

  8. Mobile genetic elements in protozoan parasites

    Indian Academy of Sciences (India)

    Mobile genetic elements, by virtue of their ability to move to new chromosomal locations, are considered important in shaping the evolutionary course of the genome. They are widespread in the biological kingdom. Among the protozoan parasites several types of transposable elements are encountered. The largest variety ...

  9. Why do probabilistic finite element analysis ?

    CERN Document Server

    Thacker, Ben H

    2008-01-01

    The intention of this book is to provide an introduction to performing probabilistic finite element analysis. As a short guideline, the objective is to inform the reader of the use, benefits and issues associated with performing probabilistic finite element analysis without excessive theory or mathematical detail.

  10. Galerkin finite element methods for wave problems

    Indian Academy of Sciences (India)

    Galerkin finite element methods for wave problems ... hp-Finite element method; continuous Galerkin methods; wave solutions; Gibbs' phenomenon. ... Department of Aerospace Engineering, Indian Institute of Technology, Kanpur 208 016, India; Institute of High Performance Computing, 1, Science Park Road, Singapore ...

  11. Element 74, the Wolfram Versus Tungsten Controversy

    Energy Technology Data Exchange (ETDEWEB)

    Holden,N.E.

    2008-08-11

    Two and a quarter centuries ago, a heavy mineral ore was found which was thought to contain a new chemical element called heavy stone (or tungsten in Swedish). A few years later, the metal was separated from its oxide and the new element (Z=74) was called wolfram. Over the years since that time, both the names wolfram and tungsten were attached to this element in various countries. Sixty years ago, IUPAC chose wolfram as the official name for the element. A few years later, under pressure from the press in the USA, the alternative name tungsten was also allowed by IUPAC. Now the original, official name 'wolfram' has been deleted by IUPAC as one of the two alternate names for the element. The history of this controversy is described here.

  12. An anisotropic, superconvergent nonconforming plate finite element

    Science.gov (United States)

    Chen, Shaochun; Yin, Li; Mao, Shipeng

    2008-10-01

    The classical finite element convergence analysis relies on the following regularity condition: there exists a constant c independent of the element K and the mesh such that hK/[rho]K[less-than-or-equals, slant]c, where hK and [rho]K are diameters of K and the biggest ball contained in K, respectively. In this paper, we construct a new, nonconforming rectangular plate element by the double set parameter method. We prove the convergence of this element without the above regularity condition. The key in our proof is to obtain the O(h2) consistency error. We also prove the superconvergence of this element for narrow rectangular meshes. Results of our numerical tests agree well with our analysis.

  13. Finite Element Modeling of Cracks and Joints

    Directory of Open Access Journals (Sweden)

    Jozef Čížik

    2006-12-01

    Full Text Available The application of finite element method to the analysis of discontinuous structural systems has received a considerable interest in recent years. Examples of problems in which discontinuities play a prominent role in the physical behaviour of a system are numerous and include various types of contact problems and layered or jointed systems. This paper gives a state-of-the-art report on the different methods developed to date for the finite element modelling of cracks and joints in discontinuous systems. Particular attention, however, has been given to the use of joint/interface elements, since their application is considered to be most appropriate for modelling of all kinds of discontinuities that may present in a structural system. A chronology of development of the main types of joint elements, including their pertinent characteristics, is also given. Advantages and disadvantages of the individual methods and types of joint elements presented are briefly discussed, together with various applications of interest.

  14. Multi-Element Lean Direct Injection Combustor Single Element Demonstration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to demonstrate the feasibility in a single element of a Multi-Element Lean Direct Injection, ME-LDI, Combustion concept. The concept will have the...

  15. Pragmatic trial design elements showed a different impact on trial interpretation and feasibility than explanatory elements

    NARCIS (Netherlands)

    Nieuwenhuis, Joost B.; Irving, Elaine; Oude Rengerink, Katrien; Lloyd, Emily; Goetz, Iris; Grobbee, Diederick E.; Stolk, Pieter; Groenwold, Rolf H H; Zuidgeest, Mira G P

    2016-01-01

    OBJECTIVE: To illustrate how pragmatic trial design elements, or inserting explanatory trial elements in pragmatic trials affect validity, generalizability, precision and operational feasibility. STUDY DESIGN AND SETTING: From illustrative examples identified through the IMI Get Real Consortium, we

  16. Alloying Characteristics of the Rare Earth Elements with the Transition Elements

    National Research Council Canada - National Science Library

    Elliott, Rodney

    1964-01-01

    The alloying characteristics of the rare earth elements with the transition metals undergo a radical change as the atomic number of the transition series increases - - transition elements in Groups...

  17. Moving KML geometry elements within Google Earth

    Science.gov (United States)

    Zhu, Liang-feng; Wang, Xi-feng; Pan, Xin

    2014-11-01

    During the process of modeling and visualizing geospatial information on the Google Earth virtual globe, there is an increasing demand to carry out such operations as moving geospatial objects defined by KML geometry elements horizontally or vertically. Due to the absence of the functionality and user interface for performing the moving transformation, it is either hard or impossible to interactively move multiple geospatial objects only using the existing Google Earth desktop application, especially when the data sets are in large volume. In this paper, we present a general framework and associated implementation methods for moving multiple KML geometry elements within Google Earth. In our proposed framework, we first load KML objects into the Google Earth plug-in, and then extract KML geometry elements from the imported KML objects. Subsequently, we interactively control the movement distance along a specified orientation by employing a custom user interface, calculate the transformed geographic location for each KML geometry element, and adjust geographic coordinates of the points in each KML objects. And finally, transformed KML geometry elements can be displayed in Google Earth for 3D visualization and spatial analysis. A key advantage of the proposed framework is that it provides a simple, uniform and efficient user interface for moving multiple KML geometry elements within Google Earth. More importantly, the proposed framework and associated implementations can be conveniently integrated into other customizable Google Earth applications to support interactively visualizing and analyzing geospatial objects defined by KML geometry elements.

  18. Combining classifiers for robust PICO element detection.

    Science.gov (United States)

    Boudin, Florian; Nie, Jian-Yun; Bartlett, Joan C; Grad, Roland; Pluye, Pierre; Dawes, Martin

    2010-05-15

    Formulating a clinical information need in terms of the four atomic parts which are Population/Problem, Intervention, Comparison and Outcome (known as PICO elements) facilitates searching for a precise answer within a large medical citation database. However, using PICO defined items in the information retrieval process requires a search engine to be able to detect and index PICO elements in the collection in order for the system to retrieve relevant documents. In this study, we tested multiple supervised classification algorithms and their combinations for detecting PICO elements within medical abstracts. Using the structural descriptors that are embedded in some medical abstracts, we have automatically gathered large training/testing data sets for each PICO element. Combining multiple classifiers using a weighted linear combination of their prediction scores achieves promising results with an f-measure score of 86.3% for P, 67% for I and 56.6% for O. Our experiments on the identification of PICO elements showed that the task is very challenging. Nevertheless, the performance achieved by our identification method is competitive with previously published results and shows that this task can be achieved with a high accuracy for the P element but lower ones for I and O elements.

  19. The effect of soil risk element contamination level on the element contents in Ocimum basilicum L.

    Directory of Open Access Journals (Sweden)

    Růžičková Petra

    2015-06-01

    Full Text Available Red basil (Ocimum basilicum L. cv. Red Rubin was cultivated in model pot experiment in the soil amended by arsenic, cadmium and lead solutions in stepwise concentrations representing the soil concentration levels of former mining area in the vicinity of Příbram, Czech Republic. The element levels added to the soil reached up to 40 mg Cd, 100 mg As, and 2000 mg Pb per kg of soil. Moreover, essential macro-and microelements as well as cyanidine contents were investigated to assess their potential interactions with the risk elements. The extractable element portions in soils determined at the end of vegetation period differed according to the individual elements. Whereas the plant-available (extractable with 0.11M CH3COOH content of Cd represented 70-100% of the added Cd, the mobile portion of Pb did not exceed 1%. The risk element content in plants reflected the increasing element contents in soil. The dominant element portions remained in plant roots indicating the limited translocation ability of risk elements to the aboveground biomass of this plant species. Although the risk element contents in amended plants significantly increased, no visible symptoms of phytotoxicity occurred. However, the effect of enhanced risk element contents on the essential element uptake was assessed. Considering inter-element relationships, elevated sulphur levels were seen in amended plants, indicating its possible role of phytochelatin synthesis in the plants. Moreover, the molybdenum contents in plant biomass dropped down with increasing risk element uptake by plants confirming As-Mo and Cd-Mo antagonism. The increasing content of cyanidine in the plant biomass confirmed possible role of anthocyanins in detoxification mechanism of risk element contaminated plants and suggested the importance of anthocyanin pigments for risk element tolerance of plants growing in contaminated areas.

  20. Isotopic Compositions of the Elements 1989

    Science.gov (United States)

    De Laeter, J. R.; Heumann, K. G.; Rosman, K. J. R.

    1991-11-01

    The Subcommittee for Isotopic Abundance Measurements (SIAM) of the IUPAC Commission on Atomic Weights and Isotopic Abundances has carried out its biennial review of isotopic compositions, as determined by mass spectrometry and other relevant methods. The Subcommittee's critical evaluation of the published literature element by element forms the basis of the Table of Isotopic Compositions of the Elements as Determined by Mass Spectrometry 1989, which is presented in this Report. Atomic Weights calculated from the tabulated isotopic abundances are consistent with Ar(E) values listed in the Table of Standard Atomic Weights 1989.

  1. Chemical studies of the heaviest elements

    Science.gov (United States)

    Nagame, Y.; Haba, H.; Tsukada, K.; Asai, M.; Toyoshima, A.; Goto, S.; Akiyama, K.; Kaneko, T.; Sakama, M.; Hirata, M.; Yaita, T.; Nishinaka, I.; Ichikawa, S.; Nakahara, H.

    2004-04-01

    Chemical studies of the transactinide elements ( Z ≥ 104) at JAERI (Japan Atomic Energy Research Institute) are reviewed and prospects for extending the studies are briefly considered. Aqueous chemistry of element 104, rutherfordium (Rf), and element 105, dubnium (Db), produced in the 248Cm( 18O, 5 n) 261Rf and 24m( 19F, 5 n) 262Db reactions, respectively, has been studied by ion-exchange chromatography on an atom-at-a-time basis. Characteristic ion-exchange behavior of Rf and Db in acidic solution is discussed.

  2. A Nonlocal Finite Element Approach to Nanobeams

    Directory of Open Access Journals (Sweden)

    Francesco Marotti de Sciarra

    2013-01-01

    Full Text Available This paper presents a consistent derivation of a new nonlocal finite element procedure in the framework of continuum mechanics and nonlocal thermodynamics for the analysis of bending of nanobeams under transverse loads. This approach is able to provide the overall performance and the influence of specific parameters in the behavior of nanobeams and it is also able to deal with nanomechanical systems by solving a reduced number of algebraic equations. An example shows that the proposed nonlocal finite element procedure, using a mesh composed by only four elements of equal size, provides the exact values in terms of transversal displacement and bending of the nanobeam.

  3. Photoshop Elements 5 The Missing Manual

    CERN Document Server

    Brundage, Barbara

    2006-01-01

    Anyone still think that Adobe Photoshop Elements is a toy version of the real thing? As the most popular photo-editing program on the market, Photoshop Elements not only has Photoshop's marvelous powers, but also has capabilities the mothership lacks. Each new version includes more tools designed specifically for today's consumer digital photo enthusiasts. The latest edition, Photoshop Elements 5, solidifies the reputation of this superb and inexpensive product with new scrapbook features, a link to online photo services, and many other improvements. In fact, there's so much to Photoshop Ele

  4. Photoshop Elements 10 The Missing Manual

    CERN Document Server

    Brundage, Barbara

    2011-01-01

    Elements 10 offers much of Photoshop's power without the huge price tag. It's a great tool for most image-editing buffs-whether you're a photographer, scrapbooker, or aspiring graphic artist. But Elements still doesn't come with a useful manual. This bestselling book helps you get the most out of the program, from the basics to advanced tips for both Windows and Mac users. The important stuff you need to know: Quickly learn your way around. Customize Elements to suit your working style.Get to work right away. Import, organize, and make quick image fixes with ease.Retouch any image. Learn how

  5. The Superheavy Elements and Anti-Gravity

    Science.gov (United States)

    Anastasovski, Petar K.

    2004-02-01

    The essence of any propulsion concept is to overcome gravity. Anti-gravity is a natural means to achieve this. Thus, the technology to pursue anti-gravity, by using superheavy elements, may provide a new propulsion paradigm. The theory of superluminal relativity provides a hypothesis for existence of elements with atomic number up to Z = 145, some of which may possess anti-gravity properties. Analysis results show that curved space-time exists demonstrating both gravitic and anti-gravitic properties not only around nuclei but inside the nuclei as well. Two groups of elements (Z Hawking, in honour of Stephen W. Hawking.

  6. The Role of Elements in Anxiety.

    Science.gov (United States)

    Młyniec, K; Gaweł, M; Doboszewska, U; Starowicz, G; Nowak, G

    2017-01-01

    Elements (bioelements) are necessary factors required for the physiological function of organisms. They are critically involved in fundamental processes of life. Extra- and intracellular message and metabolic pathway factors as well as structural components include one or many elements in their functional structure. Recent years have seen an intensification in terms of knowledge gained about the roles of elements in anxiety disorders. In this chapter we present a review of the most important current data concerning the involvement of zinc, magnesium, copper, lithium, iron, and manganese, and their deficiency, in the pathophysiology and treatment of anxiety. © 2017 Elsevier Inc. All rights reserved.

  7. Trace element analysis in soy sauce. 2

    Energy Technology Data Exchange (ETDEWEB)

    Haruyama, Yoichi; Saito, Manabu; Tomita, Michio [Kyoto Prefectural Univ. (Japan); Yoshida, Koji

    1994-12-31

    Trace elements in four kinds of soybean and three kinds of salt have been measured by means of in-air PIXE. In soybeans, which were made in Japan, America, Canada and China, six kinds of trace elements were detected, such as Mn, Fe, Ni, Cu, Zn and Br. The concentration of these elements varied depending on the place they were made. American soybean showed characteristic feature compared with other soybeans. As to the bromine concentration, American soybean contains ten times as much as Japanese one. In salts Br and Sr were detected. (author).

  8. Mineral elements in milk and dairy products

    Directory of Open Access Journals (Sweden)

    Šimun Zamberlin

    2012-06-01

    Full Text Available Mineral elements occur in milk and dairy products as inorganic ions and salts, as well as part of organic molecules, such as proteins, fats, carbohydrates and nucleic acids. The chemical form of mineral elements is important because it determines their absorption in the intestine and their biological utilization. The mineral composition of milk is not constant because it depends on lactation phase, nutritional status of the animal, and environmental and genetic factors. The objective of this research is to point out the research results of chemical form, content and nutritional importance of individual mineral elements that are present in various milks and dairy products.

  9. Finite Dynamic Elements and Modal Analysis

    Directory of Open Access Journals (Sweden)

    N.J. Fergusson

    1993-01-01

    Full Text Available A general modal analysis scheme is derived for forced response that makes use of high accuracy modes computed by the dynamic element method. The new procedure differs from the usual modal analysis in that the modes are obtained from a power series expansion for the dynamic stiffness matrix that includes an extra dynamic correction term in addition to the static stiffness matrix and the consistent mass matrix based on static displacement. A cantilevered beam example is used to demonstrate the relative accuracies of the dynamic element and the traditional finite element methods.

  10. Photoshop Elements 9 the missing manual

    CERN Document Server

    Brundage, Barbara

    2010-01-01

    Elements 9 offers much of Photoshop's power without the huge price tag. It's an ideal tool for most image-editing buffs -- including scrapbookers, photographers, and aspiring graphic artists. But Elements still doesn't come with a decent manual. This bestselling book will help you get the most out of the program, from the basics to advanced tips for both Windows and Mac. Quickly learn your way around. Customize Elements to suit your working style.Get to work right away. Import, organize, and make quick image fixes with ease.Retouch any image. Learn how to repair and restore your old and damag

  11. Electrical machine analysis using finite elements

    CERN Document Server

    Bianchi, Nicola

    2005-01-01

    OUTLINE OF ELECTROMAGNETIC FIELDSVector AnalysisElectromagnetic FieldsFundamental Equations SummaryReferencesBASIC PRINCIPLES OF FINITE ELEMENT METHODSIntroductionField Problems with Boundary ConditionsClassical Method for the Field Problem SolutionThe Classical Residual Method (Galerkin's Method)The Classical Variational Method (Rayleigh-Ritz's Method)The Finite Element MethodReferencesAPPLICATIONS OF THE FINITE ELEMENT METHOD TO TWO-DIMENSIONAL FIELDSIntroductionLinear Interpolation of the Function fApplication of the Variational MethodSimple Descriptions of Electromagnetic FieldsAppendix: I

  12. Finite Element Computational Dynamics of Rotating Systems

    Directory of Open Access Journals (Sweden)

    Jaroslav Mackerle

    1999-01-01

    Full Text Available This bibliography lists references to papers, conference proceedings and theses/dissertations dealing with finite element analysis of rotor dynamics problems that were published in 1994–1998. It contains 319 citations. Also included, as separate subsections, are finite element analyses of rotor elements – discs, shafts, spindles, and blades. Topics dealing with fracture mechanics, contact and stability problems of rotating machinery are also considered in specific sections. The last part of the bibliography presents papers dealing with specific industrial applications.

  13. MRT fuel element inspection at Dounreay

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, J.

    1997-08-01

    To ensure that their production and inspection processes are performed in an acceptable manner, ie. auditable and traceable, the MTR Fuel Element Fabrication Plant at Dounreay operates to a documented quality system. This quality system, together with the fuel element manufacturing and inspection operations, has been independently certified to ISO9002-1987, EN29002-1987 and BS5750:Pt2:1987 by Lloyd`s Register Quality Assurance Limited (LRQA). This certification also provides dual accreditation to the relevant German, Dutch and Australian certification bodies. This paper briefly describes the quality system, together with the various inspection stages involved in the manufacture of MTR fuel elements at Dounreay.

  14. Trace elements as paradigms of developmental neurotoxicants

    DEFF Research Database (Denmark)

    Grandjean, Philippe; Herz, Katherine T

    2015-01-01

    Trace elements have contributed unique insights into developmental neurotoxicity and serve as paradigms for such adverse effects. Many trace elements are retained in the body for long periods and can be easily measured to assess exposure by inexpensive analytical methods that became available...... neurotoxicants that provide a reference for other substances that may have similar adverse effects. Less evidence is available on manganese, fluoride, and cadmium, but experience from the former trace elements suggest that, with time, adverse effects are likely to be documented at exposures previously thought...

  15. A flat triangular shell element with Loof nodes

    DEFF Research Database (Denmark)

    Poulsen, Peter Noe; Damkilde, Lars

    1996-01-01

    In the formulation of flat shell elements it is difficult to achieve inter-element compatibility between membrane and transverse displacements for non-coplanar elements. Many elements lack proper nodal degrees of freedom to model intersections making the assembly of elements troublesome. A flat...... triangular shell element is established by a combination of a new plate bending element DKTL and the well-known linear membrane strain element LST, and for this element the above-mentioned deficiences are avoided. The plate bending element DKTL is based on Discrete Kirchhoff Theory and Loof nodes. The nodal...

  16. FINITE ELEMENT MODELING OF DELAMINATION PROCESS ON COMPOSITE LAMINATE USING COHESIVE ELEMENTS

    Directory of Open Access Journals (Sweden)

    S. Huzn

    2013-06-01

    Full Text Available The implementation of cohesive elements for studying the delamination process in composite laminates is presented in this paper. The commercially available finite element software ABAQUS provides the cohesive element model used in this study. Cohesive elements with traction-separation laws consist of an initial linear elastic phase, followed by a linear softening that simulates the debonding of the interface after damage initiation is inserted at the interfaces between the laminas. Simulation results from two types of composite laminate specimen, i.e., a double cantilever beam and an L-shape, show that the delamination process on laminated composites begin with debonding phenomena. These results indicate that the implementation of cohesive elements in modeling the process of delamination in laminated composite materials, using the finite element method, has been successful. Cohesive elements are able to model the phenomenon of delamination in the specimens used in this study.

  17. Finite Element Modeling on Scalable Parallel Computers

    Science.gov (United States)

    Cwik, T.; Zuffada, C.; Jamnejad, V.; Katz, D.

    1995-01-01

    A coupled finite element-integral equation was developed to model fields scattered from inhomogenous, three-dimensional objects of arbitrary shape. This paper outlines how to implement the software on a scalable parallel processor.

  18. Integrating Responsive Building Elements in Buildings

    DEFF Research Database (Denmark)

    Haase, Matthias; Amato, Alex; Heiselberg, Per

    2006-01-01

    There is a global need for a more sustainable building development. About 50% of energy is used in buildings indicating that buildings provide a considerable potential for operational energy savings. Studies were conducted with the following objectives: to perform a state-of-the-art review...... of responsive building elements, of integrated building concepts and of environmental performance assessment methods to improve and optimize responsive building elements to develop and optimize new building concepts with integration of responsive building elements, HVAC-systems as well as natural and renewable...... energy strategies to develop guidelines and procedures for estimation of environmental performance of responsive building elements and integrated building concepts This paper introduces the ideas of this collaborative work and discusses its usefulness for Hong Kong and China. Special focus was put...

  19. Finite element methods a practical guide

    CERN Document Server

    Whiteley, Jonathan

    2017-01-01

    This book presents practical applications of the finite element method to general differential equations. The underlying strategy of deriving the finite element solution is introduced using linear ordinary differential equations, thus allowing the basic concepts of the finite element solution to be introduced without being obscured by the additional mathematical detail required when applying this technique to partial differential equations. The author generalizes the presented approach to partial differential equations which include nonlinearities. The book also includes variations of the finite element method such as different classes of meshes and basic functions. Practical application of the theory is emphasised, with development of all concepts leading ultimately to a description of their computational implementation illustrated using Matlab functions. The target audience primarily comprises applied researchers and practitioners in engineering, but the book may also be beneficial for graduate students.

  20. NEW RSW & Wall Medium Mixed Element Grid

    Data.gov (United States)

    National Aeronautics and Space Administration — RSW Medium Mixed Element Grid with Viscous Wind Tunnel Wall at the root. This grid is for a node-based unstructured solver. Quad Surface Faces= 18432 Tria Surface...

  1. Elements of Social Learning Supporting Transformative Change

    African Journals Online (AJOL)

    socially critical orientation, and distilling key elements of social learning important to supporting social change. ... sound, ontologically congruent methodology to support their social-learning research and implementation. ..... first interventionist workshops contributed to strengthening the democratisation of decision-.

  2. Human Exploration Telerobotics (HET2): Astrobee Element

    Data.gov (United States)

    National Aeronautics and Space Administration — The HET2 Astrobee Element will focus on developing a new free-flying robot suitable for performing IVA work on the International Space Station (ISS). The new robot...

  3. Key Data Elements in Myeloid Leukemia

    NARCIS (Netherlands)

    Varghese, J.; Holz, C.; Neuhaus, P.; Bernardi, M.; Boehm, A.; Ganser, A.; Gore, S.; Heaney, M.; Hochhaus, A.; Hofmann, W.K.; Krug, U.; Muller-Tidow, C.; Smith, A.; Weltermann, A.; Witte, T.J.M. de; Hehlmann, R.; Dugas, M.

    2016-01-01

    Data standards consisting of key data elements for clinical routine and trial documentation harmonize documentation within and across different health care institutions making documentation more efficient and improving scientific data analysis. This work focusses on the field of myeloid leukemia

  4. Interaction Between Flow Elements in Large Enclosures

    DEFF Research Database (Denmark)

    Heiselberg, Per

    In this paper experiments in a scale model are used as a first attempt to investigate how different flow elements such as supply air jets, thermal plumes and free convection flows interact with each other in a large enclosure, if the path of each individual flow element changes and if this influe......In this paper experiments in a scale model are used as a first attempt to investigate how different flow elements such as supply air jets, thermal plumes and free convection flows interact with each other in a large enclosure, if the path of each individual flow element changes...... and if this influences the overall air flow pattern in the enclosure. The main emphasis has been put on the pathways of chilled free air jets and whether the convective flows from both distributed and concentrated heat sources affect the pathway of the jet and the air flow pattern in the enclosure as a function...

  5. Finite element analysis of tibial fractures

    DEFF Research Database (Denmark)

    Wong, Christian Nai En; Mikkelsen, Mikkel Peter W; Hansen, Leif Berner

    2010-01-01

    INTRODUCTION: Fractures of the tibial shaft are relatively common injuries. There are indications that tibial shaft fractures share characteristics in terms of site, type and local fracture mechanisms. In this study, we aimed to set up a mathematical, computer-based model using finite element...... of bony healing. The biomechanical results are the basis for fracture healing, biomechanical fall analysis and stability analysis of osteosynthesis. MATERIAL AND METHODS: A finite element model of the bony part of the lower leg was generated on the basis of computed tomography data from the Visible Human...... Project. The data consisted of 21,219 3D elements with a cortical shell and a trabecular core. Three types of load of torsion, a direct lateral load and axial compression were applied. RESULTS: The finite element linear static analysis resulted in relevant fracture localizations and indicated relevant...

  6. Finite Element Aircraft Simulation of Turbulence

    Science.gov (United States)

    1997-02-01

    A Simulation of Rotor Blade Element Turbulence (SORBET) model has been : developed for realtime aircraft simulation that accommodates stochastic : turbulence and distributed discrete gusts as a function of the terrain. This : model is applicable to c...

  7. Anisotropic damping of Timoshenko beam elements

    DEFF Research Database (Denmark)

    Hansen, M.H.

    2001-01-01

    This report contains a description of a structural damping model for Timoshenko beam elements used in the aeroelastic code HawC developed at Risø for modeling wind turbines. The model has been developed to enable modeling of turbine blades which oftenhave different damping characteristics...... for ¤flapwise¤, ¤edgewise¤ and ¤torsional¤ vibrations. The structural damping forces acting on the beam element are modeled by viscous damping described by an element damping matrix. The composition of this matrix is basedon the element mass and stiffness matrices. It is shown how the coefficients for the mass...... and stiffness contributions can be calibrated to give the desired modal damping in the complete model of a blade....

  8. Advanced finite element method in structural engineering

    CERN Document Server

    Long, Yu-Qiu; Long, Zhi-Fei

    2009-01-01

    This book systematically introduces the research work on the Finite Element Method completed over the past 25 years. Original theoretical achievements and their applications in the fields of structural engineering and computational mechanics are discussed.

  9. Computation of Asteroid Proper Elements: Recent Advances

    Science.gov (United States)

    Knežević, Z.

    2017-12-01

    The recent advances in computation of asteroid proper elements are briefly reviewed. Although not representing real breakthroughs in computation and stability assessment of proper elements, these advances can still be considered as important improvements offering solutions to some practical problems encountered in the past. The problem of getting unrealistic values of perihelion frequency for very low eccentricity orbits is solved by computing frequencies using the frequency-modified Fourier transform. The synthetic resonant proper elements adjusted to a given secular resonance helped to prove the existence of Astraea asteroid family. The preliminary assessment of stability with time of proper elements computed by means of the analytical theory provides a good indication of their poorer performance with respect to their synthetic counterparts, and advocates in favor of ceasing their regular maintenance; the final decision should, however, be taken on the basis of more comprehensive and reliable direct estimate of their individual and sample average deviations from constancy.

  10. Finite element analysis of tibial fractures

    DEFF Research Database (Denmark)

    Wong, Christian Nai En; Mikkelsen, Mikkel Peter W; Hansen, Leif Berner

    2010-01-01

    of bony healing. The biomechanical results are the basis for fracture healing, biomechanical fall analysis and stability analysis of osteosynthesis. MATERIAL AND METHODS: A finite element model of the bony part of the lower leg was generated on the basis of computed tomography data from the Visible Human...... Project. The data consisted of 21,219 3D elements with a cortical shell and a trabecular core. Three types of load of torsion, a direct lateral load and axial compression were applied. RESULTS: The finite element linear static analysis resulted in relevant fracture localizations and indicated relevant......INTRODUCTION: Fractures of the tibial shaft are relatively common injuries. There are indications that tibial shaft fractures share characteristics in terms of site, type and local fracture mechanisms. In this study, we aimed to set up a mathematical, computer-based model using finite element...

  11. Comix, a new matrix element generator

    Science.gov (United States)

    Gleisberg, Tanju; Höche, Stefan

    2008-12-01

    We present a new tree-level matrix element generator, based on the colour dressed Berends-Giele recursive relations. We discuss two new algorithms for phase space integration, dedicated to be used with large multiplicities and colour sampling.

  12. ANSYS mechanical APDL for finite element analysis

    CERN Document Server

    Thompson, Mary Kathryn

    2017-01-01

    ANSYS Mechanical APDL for Finite Element Analysis provides a hands-on introduction to engineering analysis using one of the most powerful commercial general purposes finite element programs on the market. Students will find a practical and integrated approach that combines finite element theory with best practices for developing, verifying, validating and interpreting the results of finite element models, while engineering professionals will appreciate the deep insight presented on the program's structure and behavior. Additional topics covered include an introduction to commands, input files, batch processing, and other advanced features in ANSYS. The book is written in a lecture/lab style, and each topic is supported by examples, exercises and suggestions for additional readings in the program documentation. Exercises gradually increase in difficulty and complexity, helping readers quickly gain confidence to independently use the program. This provides a solid foundation on which to build, preparing readers...

  13. Communications Stylebook: Graphics Guide: Anchor Elements

    Science.gov (United States)

    Certain elements must be displayed on the covers of all documents distributed to the public. These include an acceptable Agency identifier, such as the logo, the assigned publication number, and the EPA portal address.

  14. Rare earth elements in nuclear medicine

    Directory of Open Access Journals (Sweden)

    Kodina G.E.

    2014-12-01

    Full Text Available The review focuses on the key applications of stable and radioactive isotopes of rare earth elements in the technology of nuclear medicine, radionuclide diagnostics and therapy, as well as magnetic resonance imaging and binary radiotherapy technologies.

  15. NEW RSW & Wall Fine Mixed Element Grid

    Data.gov (United States)

    National Aeronautics and Space Administration — RSW Fine Mixed Element Grid with viscous root wind tunnel wall. This grid is for a node-based unstructured solver. Quad Surface Faces= 38016 Tria Surface Faces=...

  16. NEW RSW & Wall Coarse Mixed Element Grid

    Data.gov (United States)

    National Aeronautics and Space Administration — This is the Coarse Mixed Element Grid for the RSW with a viscous wall at the root. This grid is for a node-based unstructured solver. Quad Surface Faces= 9728 Tria...

  17. PETROLOGY AND RARE EARTH ELEMENTS (REE ...

    African Journals Online (AJOL)

    USER

    LTD PRINTED IN NIGERIA. ISSN 1596-6798 www.globaljournalseries.com, Email: info@globaljournalseries.com. PETROLOGY AND RARE EARTH ELEMENTS (REE) DISTRIBUTION. PATTERNS OF MAGMATIC ROCKS IN GBOKO AREA, LOWER. BENUE TROUGH NIGERIA: IMPLICATION FOR TECTONIC. EVOLUTION.

  18. Environmental mineralogy - Understanding element behavior in ecosystems

    Science.gov (United States)

    Brown, Gordon E., Jr.; Calas, Georges

    2011-02-01

    Environmental Mineralogy has developed over the past decade in response to the recognition that minerals are linked in many important ways with the global ecosystem. Minerals are the main repositories of the chemical elements in Earth's crust and thus are the main sources of elements needed for the development of civilization, contaminant and pollutant elements that impact global and local ecosystems, and elements that are essential plant nutrients. These elements are released from minerals through natural processes, such as chemical weathering, and anthropogenic activities, such as mining and energy production, agriculture and industrial activities, and careless waste disposal. Minerals also play key roles in the biogeochemical cycling of the elements, sequestering elements and releasing them as the primary minerals in crustal rocks undergo various structural and compositional transformations in response to physical, chemical, and biological processes that produce secondary minerals and soils. These processes have resulted in the release of toxic elements such as arsenic in groundwater aquifers, which is having a major impact on the health of millions of people in South and Southeast Asia. The interfaces between mineral surfaces and aqueous solutions are the locations of most chemical reactions that control the composition of the natural environment, including the composition of natural waters. The nuclear fuel cycle, from uranium mining to the disposition of high-level nuclear waste, is also intimately related to minerals. A fundamental understanding of these processes requires molecular-scale information about minerals, their bulk structures and properties such as solubility, their surfaces, and their interactions with aqueous solutions, atmospheric and soil gases, natural organic matter, and biological organisms. Gaining this understanding is further complicated by the presence of natural, incidental, and manufactured nanoparticles in the environment, which are

  19. SQL Application for Periodic System of Elements

    Directory of Open Access Journals (Sweden)

    Delia GLIGOR

    2004-02-01

    Full Text Available The paper presents SQL power of periodic system using for didactic aim. The article is based on a PHP application developed to present a periodic system in a form, which can be used for answer at different questions, which can be asked related at the structure of elements. There are presented all queries that are needed to be use for classification of elements after different properties, the database, and user interface design.

  20. Poole-frenkel piezoconductive element and sensor

    Science.gov (United States)

    Habermehl, Scott D.

    2004-08-03

    A new class of highly sensitive piezoconductive strain sensor elements and sensors has been invented. The new elements function under conditions such that electrical conductivity is dominated by Poole-Frenkel transport. A substantial piezoconductive effect appears in this regime, allowing the new sensors to exhibit sensitivity to applied strain as much as two orders of magnitude in excess of prior art sensors based on doped silicon.

  1. Functional Element Test Tool and Method

    Science.gov (United States)

    2001-07-03

    functional element 6 involved in the run test case step 8 6 of a test. SAFE test tool 7 10 preferably operates in several selectable modes of...options 9 (e.g., data initiation buttons) are displayed as dictated by 10 each test case. The run test case step 86 is then performed 11 under...19 object functional element being tested during run test case step 20 8 6 would be maintained via SAFE test tool 10 for later 21 comparison or

  2. Surgery simulation using fast finite elements

    DEFF Research Database (Denmark)

    Bro-Nielsen, Morten

    1996-01-01

    This paper describes our recent work on real-time surgery simulation using fast finite element models of linear elasticity. In addition, we discuss various improvements in terms of speed and realism......This paper describes our recent work on real-time surgery simulation using fast finite element models of linear elasticity. In addition, we discuss various improvements in terms of speed and realism...

  3. Quadrilateral/hexahedral finite element mesh coarsening

    Science.gov (United States)

    Staten, Matthew L; Dewey, Mark W; Scott, Michael A; Benzley, Steven E

    2012-10-16

    A technique for coarsening a finite element mesh ("FEM") is described. This technique includes identifying a coarsening region within the FEM to be coarsened. Perimeter chords running along perimeter boundaries of the coarsening region are identified. The perimeter chords are redirected to create an adaptive chord separating the coarsening region from a remainder of the FEM. The adaptive chord runs through mesh elements residing along the perimeter boundaries of the coarsening region. The adaptive chord is then extracted to coarsen the FEM.

  4. Heavy element research at FLNR (Dubna)

    Energy Technology Data Exchange (ETDEWEB)

    Oganessian, Yu. [Joint Institute for Nuclear Research, Flerov Laboratory of Nuclear Reactions, Moscow region, Dubna (Russian Federation)

    2009-12-15

    The setting of the experiments is described and the results obtained on the synthesis of the heaviest nuclides in reactions induced by {sup 48}Ca projectiles are presented. The decay properties of the new nuclei confirm the theoretical predictions about the new nuclear shells and the ''islands of stability'' of superheavy elements. Briefly, also the results of the first experiments aimed to study the atomic and chemical properties of element 112 are reported. (orig.)

  5. Børnehaven De fire Elementer

    DEFF Research Database (Denmark)

    Sørensen, Hanne Værum

    I projektet undersøges og beskrives arbejdet i børnehaven De fire Elementer, med særligt fokus på kønsopdelingen fire formiddage om ugen.......I projektet undersøges og beskrives arbejdet i børnehaven De fire Elementer, med særligt fokus på kønsopdelingen fire formiddage om ugen....

  6. Trace elements distribution in environmental compartments

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Juliana C. de; Peres, Sueli da Silva; Godoy, Maria Luiza D.P., E-mail: suelip@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-11-01

    Trace elements term defines the presence of low concentrations metals at environment. Some of them are considered biologically essential, as Co, Cu and Mn. Others can cause detriment to environment and human health, as Pb, Cd, Hg, As, Ti and U. A large number of them have radioactive isotopes, implying the evaluation of risks for human health should be done considering the precepts of environmental radiological protection. The ecosystem pollution with trace elements generates changes at the geochemistry cycle of these elements and in environmental quality. Soils have single characteristics when compared with another components of biosphere (air, water and biota), cause they introduce themselves not only as a drain towards contaminants, but also as natural buffer that control the transport of chemical elements and other substances for atmosphere, hydrosphere and biota. The main purpose of environmental monitoring program is to evaluate the levels of contaminants in the various compartments of the environment: natural or anthropogenic, and to assess the contribution of a potential contaminant source on the environment. Elemental Composition for the collected samples was determined by inductively coupled plasma mass spectroscopy. The main objective of this work was to evaluate the map baseline of concentration of interest trace elements in environmental samples of water, sediment and soil from Environmental Monitoring Program of Instituto de Radioprotecao e Dosimetria (IRD). The samples were analyzed using an inductively coupled plasma mass spectrometer (ICP-MS) at IRD. >From the knowledge of trace elements concentrations, could be evaluated the environmental quality parameters at the studied ecosystems. The data allowed evaluating some relevant aspects of the study of trace elements in soil and aquatic systems, with emphasis at the distribution, concentration and identification of main anthropic sources of contamination at environment. (author)

  7. The finite element method in electromagnetics

    CERN Document Server

    Jin, Jianming

    2014-01-01

    A new edition of the leading textbook on the finite element method, incorporating major advancements and further applications in the field of electromagnetics The finite element method (FEM) is a powerful simulation technique used to solve boundary-value problems in a variety of engineering circumstances. It has been widely used for analysis of electromagnetic fields in antennas, radar scattering, RF and microwave engineering, high-speed/high-frequency circuits, wireless communication, electromagnetic compatibility, photonics, remote sensing, biomedical engineering, and space exploration. The

  8. Explicit Instruction Elements in Core Reading Programs

    OpenAIRE

    Child, Angela R.

    2012-01-01

    Classroom teachers are provided instructional recommendations for teaching reading from their adopted core reading programs (CRPs). Explicit instruction elements or what is also called instructional moves, including direct explanation, modeling, guided practice, independent practice, discussion, feedback, and monitoring, were examined within CRP reading lessons. This study sought to answer the question: What elements of explicit instruction or instructional moves are included in the five most...

  9. Quantum algorithms and the finite element method

    OpenAIRE

    Montanaro, Ashley; Pallister, Sam

    2015-01-01

    The finite element method is used to approximately solve boundary value problems for differential equations. The method discretises the parameter space and finds an approximate solution by solving a large system of linear equations. Here we investigate the extent to which the finite element method can be accelerated using an efficient quantum algorithm for solving linear equations. We consider the representative general question of approximately computing a linear functional of the solution t...

  10. Mechanical Design Desktop for Machine Elements

    OpenAIRE

    Subramanian, Anuj

    2000-01-01

    The design of machine elements such as belts, chain and sprocket, gears, cams, bearings, etc., is a complex procedure. The analytical procedure to design such elements is non-linear, often based upon statistical information and frequently heuristic in nature. The procedure is iterative and involves choosing various weighing factors based upon the application and usage. The procedure is greatly influenced by a designer's intuitive skill and experience. Due to ...

  11. Finite element modeling of the human pelvis

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, B.

    1995-11-01

    A finite element model of the human pelvis was created using a commercial wire frame image as a template. To test the final mesh, the model`s mechanical behavior was analyzed through finite element analysis and the results were displayed graphically as stress concentrations. In the future, this grid of the pelvis will be integrated with a full leg model and used in side-impact car collision simulations.

  12. Molecular clusters of the main group elements

    CERN Document Server

    Driess, Matthias

    2008-01-01

    ""To summarize, Molecular Clusters of the Main Group Elements is certainly not a popular science book, nor is it a textbook; it is a very good, up-to-date collection of articles for the specialist. Als Fazit bleibt: Molecular Clusters of the Main Group Elements ist sicher kein populissenschaftliches Werk, auch kein Lehrbuch, aber eine gelungene, hoch aktuelle Zusammenstellung fen interessierten Fachmann."" -Michael Ruck, TU Dresden, Angewandte Chemie, 2004 - 116/36 + International Edition 2004 - 43/36

  13. Semiclassical form factor of matrix element fluctuations

    CERN Document Server

    Eckhardt, B; Eckhardt, Bruno; Main, Joerg

    1995-01-01

    We analyze within a semiclassical approximation the form factor for the fluctuations of quantum matrix elements around their classical average. We find two contributions: one is proportional to the form factor for the density of states, with an amplitude determined by the squared average of the matrix elements. The other is constant and related to the fluctuations of finite time classical trajectory segments around the phase space average. The results are illustrated for an observable in the quadratic Zeeman effect.

  14. Coronavirus cis-Acting RNA Elements.

    Science.gov (United States)

    Madhugiri, R; Fricke, M; Marz, M; Ziebuhr, J

    2016-01-01

    Coronaviruses have exceptionally large RNA genomes of approximately 30 kilobases. Genome replication and transcription is mediated by a multisubunit protein complex comprised of more than a dozen virus-encoded proteins. The protein complex is thought to bind specific cis-acting RNA elements primarily located in the 5'- and 3'-terminal genome regions and upstream of the open reading frames located in the 3'-proximal one-third of the genome. Here, we review our current understanding of coronavirus cis-acting RNA elements, focusing on elements required for genome replication and packaging. Recent bioinformatic, biochemical, and genetic studies suggest a previously unknown level of conservation of cis-acting RNA structures among different coronavirus genera and, in some cases, even beyond genus boundaries. Also, there is increasing evidence to suggest that individual cis-acting elements may be part of higher-order RNA structures involving long-range and dynamic RNA-RNA interactions between RNA structural elements separated by thousands of nucleotides in the viral genome. We discuss the structural and functional features of these cis-acting RNA elements and their specific functions in coronavirus RNA synthesis. © 2016 Elsevier Inc. All rights reserved.

  15. Comparison of hexahedral and tetrahedral elements in finite element analysis of the foot and footwear.

    Science.gov (United States)

    Tadepalli, Srinivas C; Erdemir, Ahmet; Cavanagh, Peter R

    2011-08-11

    Finite element analysis has been widely used in the field of foot and footwear biomechanics to determine plantar pressures as well as stresses and strains within soft tissue and footwear materials. When dealing with anatomical structures such as the foot, hexahedral mesh generation accounts for most of the model development time due to geometric complexities imposed by branching and embedded structures. Tetrahedral meshing, which can be more easily automated, has been the approach of choice to date in foot and footwear biomechanics. Here we use the nonlinear finite element program Abaqus (Simulia, Providence, RI) to examine the advantages and disadvantages of tetrahedral and hexahedral elements under compression and shear loading, material incompressibility, and frictional contact conditions, which are commonly seen in foot and footwear biomechanics. This study demonstrated that for a range of simulation conditions, hybrid hexahedral elements (Abaqus C3D8H) consistently performed well while hybrid linear tetrahedral elements (Abaqus C3D4H) performed poorly. On the other hand, enhanced quadratic tetrahedral elements with improved stress visualization (Abaqus C3D10I) performed as well as the hybrid hexahedral elements in terms of contact pressure and contact shear stress predictions. Although the enhanced quadratic tetrahedral element simulations were computationally expensive compared to hexahedral element simulations in both barefoot and footwear conditions, the enhanced quadratic tetrahedral element formulation seems to be very promising for foot and footwear applications as a result of decreased labor and expedited model development, all related to facilitated mesh generation. Copyright © 2011. Published by Elsevier Ltd.

  16. ElemeNT: a computational tool for detecting core promoter elements

    Science.gov (United States)

    Sloutskin, Anna; Danino, Yehuda M; Orenstein, Yaron; Zehavi, Yonathan; Doniger, Tirza; Shamir, Ron; Juven-Gershon, Tamar

    2015-01-01

    Core promoter elements play a pivotal role in the transcriptional output, yet they are often detected manually within sequences of interest. Here, we present 2 contributions to the detection and curation of core promoter elements within given sequences. First, the Elements Navigation Tool (ElemeNT) is a user-friendly web-based, interactive tool for prediction and display of putative core promoter elements and their biologically-relevant combinations. Second, the CORE database summarizes ElemeNT-predicted core promoter elements near CAGE and RNA-seq-defined Drosophila melanogaster transcription start sites (TSSs). ElemeNT's predictions are based on biologically-functional core promoter elements, and can be used to infer core promoter compositions. ElemeNT does not assume prior knowledge of the actual TSS position, and can therefore assist in annotation of any given sequence. These resources, freely accessible at http://lifefaculty.biu.ac.il/gershon-tamar/index.php/resources, facilitate the identification of core promoter elements as active contributors to gene expression. PMID:26226151

  17. Macro-Elements and Trace Elements in Cereal Grains Cultivated in Latvia

    Directory of Open Access Journals (Sweden)

    Jākobsone Ida

    2015-09-01

    Full Text Available Cereal-based foods have great importance in the compensation of micro- and trace element deficiency, because 50% of the foods produced worldwide are made up of cereal grains. The aim of the research was to determine the concentration of macro-elements and trace elements in different cereals cultivated in Latvia. Various cereals were used in the research: rye (n = 45, barley (n = 54, spring wheat (n = 27, winter wheat (n = 53, triticale (n = 45 and oats (n = 42. Thirteen macro- and trace elements (Cd, Pb, Ni, Cr, Al, Cu, K, Na, Mn, Fe, Zn, Mg, Ca were determined in cereal grain samples (n = 266. Macro-elements and trace elements varied significantly (p < 0.01 or p < 0.001. The highest concentrations of macro- and trace elements were found in oats and the lowest in rye. The obtained data will expand the opportunity for food and nutrition scientists to evaluate content of the examined elements in grain products, and dietary consumption (bioavailability of the examined macro-elements and trace elements.

  18. Finite element simulation of articular contact mechanics with quadratic tetrahedral elements.

    Science.gov (United States)

    Maas, Steve A; Ellis, Benjamin J; Rawlins, David S; Weiss, Jeffrey A

    2016-03-21

    Although it is easier to generate finite element discretizations with tetrahedral elements, trilinear hexahedral (HEX8) elements are more often used in simulations of articular contact mechanics. This is due to numerical shortcomings of linear tetrahedral (TET4) elements, limited availability of quadratic tetrahedron elements in combination with effective contact algorithms, and the perceived increased computational expense of quadratic finite elements. In this study we implemented both ten-node (TET10) and fifteen-node (TET15) quadratic tetrahedral elements in FEBio (www.febio.org) and compared their accuracy, robustness in terms of convergence behavior and computational cost for simulations relevant to articular contact mechanics. Suitable volume integration and surface integration rules were determined by comparing the results of several benchmark contact problems. The results demonstrated that the surface integration rule used to evaluate the contact integrals for quadratic elements affected both convergence behavior and accuracy of predicted stresses. The computational expense and robustness of both quadratic tetrahedral formulations compared favorably to the HEX8 models. Of note, the TET15 element demonstrated superior convergence behavior and lower computational cost than both the TET10 and HEX8 elements for meshes with similar numbers of degrees of freedom in the contact problems that we examined. Finally, the excellent accuracy and relative efficiency of these quadratic tetrahedral elements was illustrated by comparing their predictions with those for a HEX8 mesh for simulation of articular contact in a fully validated model of the hip. These results demonstrate that TET10 and TET15 elements provide viable alternatives to HEX8 elements for simulation of articular contact mechanics. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. An algorithm for domain decomposition in finite element analysis

    Science.gov (United States)

    Al-Nasra, M.; Nguyen, D. T.

    1991-01-01

    A simple and efficient algorithm is described for automatic decomposition of an arbitrary finite element domain into a specified number of subdomains for finite element and substructuring analysis in a multiprocessor computer environment. The algorithm is designed to balance the work loads, to minimize the communication among processors and to minimize the bandwidths of the resulting system of equations. Small- to large-scale finite element models, which have two-node elements (truss, beam element), three-node elements (triangular element) and four-node elements (quadrilateral element), are solved on the Convex computer to illustrate the effectiveness of the proposed algorithm. A FORTRAN computer program is also included.

  20. A Family of Uniform Strain Tetrahedral Elements and a Method for Connecting Dissimilar Finite Element Meshes

    Energy Technology Data Exchange (ETDEWEB)

    Dohrmann, C.R.; Heinstein, M.W.; Jung, J.; Key, S.W.

    1999-01-01

    This report documents a collection of papers on a family of uniform strain tetrahedral finite elements and their connection to different element types. Also included in the report are two papers which address the general problem of connecting dissimilar meshes in two and three dimensions. Much of the work presented here was motivated by the development of the tetrahedral element described in the report "A Suitable Low-Order, Eight-Node Tetrahedral Finite Element For Solids," by S. W. Key {ital et al.}, SAND98-0756, March 1998. Two basic issues addressed by the papers are: (1) the performance of alternative tetrahedral elements with uniform strain and enhanced uniform strain formulations, and (2) the proper connection of tetrahedral and other element types when two meshes are "tied" together to represent a single continuous domain.

  1. Trace elements in hazardous mineral fibres.

    Science.gov (United States)

    Bloise, Andrea; Barca, Donatella; Gualtieri, Alessandro Francesco; Pollastri, Simone; Belluso, Elena

    2016-09-01

    Both occupational and environmental exposure to asbestos-mineral fibres can be associated with lung diseases. The pathogenic effects are related to the dimension, biopersistence and chemical composition of the fibres. In addition to the major mineral elements, mineral fibres contain trace elements and their content may play a role in fibre toxicity. To shed light on the role of trace elements in asbestos carcinogenesis, knowledge on their concentration in asbestos-mineral fibres is mandatory. It is possible that trace elements play a synergetic factor in the pathogenesis of diseases caused by the inhalation of mineral fibres. In this paper, the concentration levels of trace elements from three chrysotile samples, four amphibole asbestos samples (UICC amosite, UICC anthophyllite, UICC crocidolite and tremolite) and fibrous erionite from Jersey, Nevada (USA) were determined using inductively coupled plasma mass spectrometry (ICP-MS). For all samples, the following trace elements were measured: Li, Be, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, As, Rb, Sr, Y, Sb, Cs, Ba, La, Pb, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, U. Their distribution in the various mineral species is thoroughly discussed. The obtained results indicate that the amount of trace metals such as Mn, Cr, Co, Ni, Cu and Zn is higher in anthophyllite and chrysotile samples, whereas the amount of rare earth elements (REE) is higher in erionite and tremolite samples. The results of this work can be useful to the pathologists and biochemists who use asbestos minerals and fibrous erionite in-vitro studies as positive cyto- and geno-toxic standard references. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Trace element patterns in marine macroalgae.

    Science.gov (United States)

    Malea, Paraskevi; Kevrekidis, Theodoros

    2014-10-01

    Novel information on interspecific variation in trace element accumulation in seaweeds is provided. Concentrations and concentration factors (CFs) of a wide set of elements (As, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Se, Sr, U, V and Zn) in 26 dominant macroalgae from the Gulf of Thessaloniki, Aegean Sea were determined and compared. Uni-and multivariate data analyses were applied. Phaeophyceae showed higher concentrations and CFs of As and Sr than Rhodophyta and Chlorophyta, indicating that the accumulation of these elements is closely related to species biochemical composition. Filamentous macroalgae displayed higher concentrations and CFs of several elements, particularly Cd, Co, Cr, Cu, Mn and V than sheet-like, coarsely-branched and/or thick-leathery macroalgae, irrespective of phylogenetic relationships, indicating that the accumulation of several elements is largely related to thallus morphology and growth strategy. On a species basis, Cystoseira spp. showed both the highest concentrations and CFs of As, Padina pavonica of Sr and U, Ceramium spp. of Mn, Ceramium and Cladophora species of Co and Cu, Cladophora prolifera of Cr and Polysiphonia deusta and Ulva clathrata of Cd. Se concentration in Ulva rigida correlated positively with seawater Se concentration, and As concentration in this species with sediment As concentration. Thereby, these seaweeds could be regarded as potential biomonitors for the respective elements. A literature review was performed and global element concentrations and CFs were presented for seaweeds from genera collected during this survey. The data presented can contribute to the interpretation of biomonitoring data and the design of biomonitoring programs for the protection and management of coastal environments. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Introduction to finite and spectral element methods using Matlab

    CERN Document Server

    Pozrikidis, Constantine

    2014-01-01

    The Finite Element Method in One Dimension. Further Applications in One Dimension. High-Order and Spectral Elements in One Dimension. The Finite Element Method in Two Dimensions. Quadratic and Spectral Elements in Two Dimensions. Applications in Mechanics. Viscous Flow. Finite and Spectral Element Methods in Three Dimensions. Appendices. References. Index.

  4. Superheavy Element Studies with TASCA at GSI: Spectroscopy of Element 115 Decay Chains

    Science.gov (United States)

    Rudolph, Dirk

    Experimental campaigns on investigations of the superheavy elements 115, 117, 119, and 120 were conducted 2011 and 2012 at the gas-filled "TransActinide Separator and Chemistry Apparatus" (TASCA) at the GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany. Nuclear structure implications of first-ever α-photon coincidence spectroscopy on element 115 and its daughters obtained with the TASISpec set-up are discussed, likewise possible connections between decay chains associated with elements 115 and 117.

  5. Augmented weak forms and element-by-element preconditioners: Efficient iterative strategies for structural finite elements. A preliminary study

    Science.gov (United States)

    Muller, A.; Hughes, T. J. R.

    1984-01-01

    A weak formulation in structural analysis that provides well conditioned matrices suitable for iterative solutions is presented. A mixed formulation ensures the proper representation of the problem and the constitutive relations are added in a penalized form. The problem is solved by a double conjugate gradient algorithm combined with an element by element approximate factorization procedure. The double conjugate gradient strategy resembles Uzawa's variable-length type algorithms the main difference is the presence of quadratic terms in the mixed variables. In the case of shear deformable beams these terms ensure that the proper finite thickness solution is obtained.

  6. Trace elements record complex histories in diogenites

    Science.gov (United States)

    Balta, J. B.; Beck, A. W.; McSween, H. Y.

    2012-12-01

    Diogenite meteorites are cumulate rocks composed mostly of orthopyroxene and chemically linked to eucrites (basaltic) and howardites (brecciated mixtures of diogenites and eucrites). Together, they represent the largest single family of achondrite meteorites delivered to Earth, and have been spectrally linked to the asteroid 4 Vesta, the largest remaining basaltic protoplanet. However, this spectral link is non-unique as many basaltic asteroids likely formed and were destroyed in the early solar system. Recent work suggested that Vesta may be an unlikely parent body for the diogenites based on correlations between trace elements and short-lived isotope decay products, which would be unlikely to survive on a body as large as Vesta due to its long cooling history [1]. Recent analyses of terrestrial and martian olivines have demonstrated that trace element spatial distributions can preserve evidence of their crystallization history even when major elements have been homogenized [2]. We have mapped minor elements including Cr, Al, and Ti in seemingly homogeneous diogenite orthopyroxenes and found a variety of previously unobserved textures. The pyroxenes in one sample (GRA 98108) are seemingly large grains of variable shapes and sizes, but the trace elements reveal internal grain boundaries between roughly-equal sized original subgrains, with equilibrated metamorphic triple junctions between them and trace element depletions at the boundaries. These trends suggest extraction of trace elements by a magma along those relict grain boundaries during a reheating event. Two other samples show evidence of fracturing and annealing, with trace element mobility within grains. One sample appears to have remained a closed system during annealing (MET 01084), while the other has interacted with a fluid or magma to move elements along annealed cracks (LEW 88679). These relict features establish that the history of diogenite pyroxenes is more complex than their homogeneous major

  7. Trace elements in termites by PIXE analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, T. E-mail: tsuyoshi@termite.kuwri.kyoto-u.ac.jp; Kagemori, N.; Kawai, S.; Sera, K.; Futatsugawa, S

    2002-04-01

    Trace elements in a Japanese subterranean xylophagous termite, Coptotermes formosanus Shiraki, were analyzed by the PIXE method. The total amount of the 14 predominant elements out of 27 detected in an intact termite was higher in a soldier termite (23 000 {mu}g/g) than in a worker termite (10 000 {mu}g/g). A block of wood (Pinus densiflora Sieb. et Zucc.) for termite feed had a much lower concentration (3600 {mu}g/g) compared with that in an intact termite. This probably relates the functional bio-condensation and/or bio-recycling of trace elements in C. formosanus. When a termite was separated into three anatomical parts, head, degutted body and gut, the worker gut contained the highest total amount of the 14 predominant measured elements (31 000 {mu}g/g). This might be correlated with the higher activity of food digestion and energy production in the worker gut. Moreover, the mandible of the soldier head, with an exoskeleton that is intensely hardened, showed a preferential distribution of Mn and Fe. These results suggest that the characteristic localization of elements will be closely related to the functional role of the individual anatomical part of C. formosanus.

  8. Deletion of ultraconserved elements yields viable mice

    Energy Technology Data Exchange (ETDEWEB)

    Ahituv, Nadav; Zhu, Yiwen; Visel, Axel; Holt, Amy; Afzal, Veena; Pennacchio, Len A.; Rubin, Edward M.

    2007-07-15

    Ultraconserved elements have been suggested to retainextended perfect sequence identity between the human, mouse, and ratgenomes due to essential functional properties. To investigate thenecessities of these elements in vivo, we removed four non-codingultraconserved elements (ranging in length from 222 to 731 base pairs)from the mouse genome. To maximize the likelihood of observing aphenotype, we chose to delete elements that function as enhancers in amouse transgenic assay and that are near genes that exhibit markedphenotypes both when completely inactivated in the mouse as well as whentheir expression is altered due to other genomic modifications.Remarkably, all four resulting lines of mice lacking these ultraconservedelements were viable and fertile, and failed to reveal any criticalabnormalities when assayed for a variety of phenotypes including growth,longevity, pathology and metabolism. In addition more targeted screens,informed by the abnormalities observed in mice where genes in proximityto the investigated elements had been altered, also failed to revealnotable abnormalities. These results, while not inclusive of all thepossible phenotypic impact of the deleted sequences, indicate thatextreme sequence constraint does not necessarily reflect crucialfunctions required for viability.

  9. Phylogenetic footprinting to find functional DNA elements.

    Science.gov (United States)

    Ganley, Austen R D; Kobayashi, Takehiko

    2007-01-01

    Phylogenetic footprinting is powerful technique for finding functional elements from sequence data. Functional elements are thought to have greater sequence constraint than nonfunctional elements, and, thus, undergo a slower rate of sequence change through time. Phylogenetic footprinting uses comparisons of homologous sequences from closely related organisms to identify "phylogenetic footprints," regions with slower rates of sequence change than background. This does not require prior characterization of the sequence in question, therefore, it can be used in a wide range of applications. In particular, it is useful for the identification of functional elements in noncoding DNA, which are traditionally difficult to detect. Here, we describe in detail how to perform a simple yet powerful phylogenetic footprinting analysis. As an example, we use ribosomal DNA repeat sequences from various Saccharomyces yeasts to find functional noncoding DNA elements in the intergenic spacer, and explain critical considerations in performing phylogenetic footprinting analyses, including the number of species and species range, and some of the available software. Our methods are broadly applicable and should appeal to molecular biologists with little experience in bioinformatics.

  10. Photoacoustic active ultrasound element for catheter tracking

    Science.gov (United States)

    Guo, Xiaoyu; Tavakoli, Behnoosh; Kang, Hyun-Jae; Kang, Jin U.; Etienne-Cummings, Ralph; Boctor, Emad M.

    2014-03-01

    In recent years, various methods have been developed to improve ultrasound based interventional tool tracking. However, none of them has yet provided a solution that effectively solves the tool visualization and mid-plane localization accuracy problem and fully meets the clinical requirements. Our previous work has demonstrated a new active ultrasound pattern injection system (AUSPIS), which integrates active ultrasound transducers with the interventional tool, actively monitors the beacon signals and transmits ultrasound pulses back to the US probe with the correct timing. Ex vivo and in vivo experiments have proved that AUSPIS greatly improved tool visualization, and provided tool-tip localization accuracy of less than 300 μm. In the previous work, the active elements were made of piezoelectric materials. However, in some applications the high driving voltage of the piezoelectric element raises safety concerns. In addition, the metallic electrical wires connecting the piezoelectric element may also cause artifacts in CT and MR imaging. This work explicitly focuses on an all-optical active ultrasound element approach to overcome these problems. In this approach, the active ultrasound element is composed of two optical fibers - one for transmission and one for reception. The transmission fiber delivers a laser beam from a pulsed laser diode and excites a photoacoustic target to generate ultrasound pulses. The reception fiber is a Fabry-Pérot hydrophone. We have made a prototype catheter and performed phantom experiments. Catheter tip localization, mid-plan detection and arbitrary pattern injection functions have been demonstrated using the all-optical AUSPIS.

  11. Chemical investigation of hassium (element 108).

    Science.gov (United States)

    Düllmann, Ch E; Brüchle, W; Dressler, R; Eberhardt, K; Eichler, B; Eichler, R; Gäggeler, H W; Ginter, T N; Glaus, F; Gregorich, K E; Hoffman, D C; Jäger, E; Jost, D T; Kirbach, U W; Lee, D M; Nitsche, H; Patin, J B; Pershina, V; Piguet, D; Qin, Z; Schädel, M; Schausten, B; Schimpf, E; Schött, H-J; Soverna, S; Sudowe, R; Thörle, P; Timokhin, S N; Trautmann, N; Türler, A; Vahle, A; Wirth, G; Yakushev, A B; Zielinski, P M

    2002-08-22

    The periodic table provides a classification of the chemical properties of the elements. But for the heaviest elements, the transactinides, this role of the periodic table reaches its limits because increasingly strong relativistic effects on the valence electron shells can induce deviations from known trends in chemical properties. In the case of the first two transactinides, elements 104 and 105, relativistic effects do indeed influence their chemical properties, whereas elements 106 and 107 both behave as expected from their position within the periodic table. Here we report the chemical separation and characterization of only seven detected atoms of element 108 (hassium, Hs), which were generated as isotopes (269)Hs (refs 8, 9) and (270)Hs (ref. 10) in the fusion reaction between (26)Mg and (248)Cm. The hassium atoms are immediately oxidized to a highly volatile oxide, presumably HsO(4), for which we determine an enthalpy of adsorption on our detector surface that is comparable to the adsorption enthalpy determined under identical conditions for the osmium oxide OsO(4). These results provide evidence that the chemical properties of hassium and its lighter homologue osmium are similar, thus confirming that hassium exhibits properties as expected from its position in group 8 of the periodic table.

  12. Biological toxicity of lanthanide elements on algae.

    Science.gov (United States)

    Tai, Peidong; Zhao, Qing; Su, Dan; Li, Peijun; Stagnitti, Frank

    2010-08-01

    The biological toxicity of lanthanides on marine monocellular algae was investigated. The specific objective of this research was to establish the relationship between the abundance in the seawater of lanthanides and their biological toxicities on marine monocellular algae. The results showed that all single lanthanides had similar toxic effects on Skeletonema costatum. High concentrations of lanthanides (29.04+/-0.61 micromol L(-1)) resulted in 50% reduction in growth of algae compared to the controls (0 micromol L(-1)) after 96 h (96 h-EC50). The biological toxicity of 13 lanthanides on marine monocellular algae was unrelated with the abundance of different lanthanide elements in nature, and the "Harkins rule" was not appropriate for the lanthanides. A mixed solution that contained equivalent concentrations of each lanthanide element had the same inhibition effect on algae cells as each individual lanthanide element at the same total concentration. This phenomenon is unique compared to the groups of other elements in the periodic table. Hence, we speculate that the monocellular organisms might not be able to sufficiently differentiate between the almost chemically identical lanthanide elements. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  13. Developments of Mindlin-Reissner Plate Elements

    Directory of Open Access Journals (Sweden)

    Song Cen

    2015-01-01

    Full Text Available Since 1960s, how to develop high-performance plate bending finite elements based on different plate theories has attracted a great deal of attention from finite element researchers, and numerous models have been successfully constructed. Among these elements, the most popular models are usually formulated by two theoretical bases: the Kirchhoff plate theory and the Mindlin-Reissener plate theory. Due to the advantages that only C0 continuity is required and the effect of transverse shear strain can be included, the latter one seems more rational and has obtained more attention. Through abundant works, different types of Mindlin-Reissener plate models emerged in many literatures and have been applied to solve various engineering problems. However, it also brings FEM users a puzzle of how to choose a “right” one. The main purpose of this paper is to present an overview of the development history of the Mindlin-Reissner plate elements, exhibiting the state-of-art in this research field. At the end of the paper, a promising method for developing “shape-free” plate elements is recommended.

  14. Trace elements in glucometabolic disorders: an update

    Directory of Open Access Journals (Sweden)

    Wiernsperger Nicolas

    2010-12-01

    Full Text Available Abstract Many trace elements, among which metals, are indispensable for proper functioning of a myriad of biochemical reactions, more particularly as enzyme cofactors. This is particularly true for the vast set of processes involved in regulation of glucose homeostasis, being it in glucose metabolism itself or in hormonal control, especially insulin. The role and importance of trace elements such as chromium, zinc, selenium, lithium and vanadium are much less evident and subjected to chronic debate. This review updates our actual knowledge concerning these five trace elements. A careful survey of the literature shows that while theoretical postulates from some key roles of these elements had led to real hopes for therapy of insulin resistance and diabetes, the limited experience based on available data indicates that beneficial effects and use of most of them are subjected to caution, given the narrow window between safe and unsafe doses. Clear therapeutic benefit in these pathologies is presently doubtful but some data indicate that these metals may have a clinical interest in patients presenting deficiencies in individual metal levels. The same holds true for an association of some trace elements such as chromium or zinc with oral antidiabetics. However, this area is essentially unexplored in adequate clinical trials, which are worth being performed.

  15. Writing analytic element programs in Python.

    Science.gov (United States)

    Bakker, Mark; Kelson, Victor A

    2009-01-01

    The analytic element method is a mesh-free approach for modeling ground water flow at both the local and the regional scale. With the advent of the Python object-oriented programming language, it has become relatively easy to write analytic element programs. In this article, an introduction is given of the basic principles of the analytic element method and of the Python programming language. A simple, yet flexible, object-oriented design is presented for analytic element codes using multiple inheritance. New types of analytic elements may be added without the need for any changes in the existing part of the code. The presented code may be used to model flow to wells (with either a specified discharge or drawdown) and streams (with a specified head). The code may be extended by any hydrogeologist with a healthy appetite for writing computer code to solve more complicated ground water flow problems. Copyright © 2009 The Author(s). Journal Compilation © 2009 National Ground Water Association.

  16. Transposable elements in the Anopheles funestus transcriptome.

    Science.gov (United States)

    Fernández-Medina, Rita D; Carareto, Claudia M A; Struchiner, Cláudio J; Ribeiro, José M C

    2017-06-01

    Transposable elements (TEs) are present in most of the eukaryotic genomes and their impact on genome evolution is increasingly recognized. Although there is extensive information on the TEs present in several eukaryotic genomes, less is known about the expression of these elements at the transcriptome level. Here we present a detailed analysis regarding the expression of TEs in Anopheles funestus, the second most important vector of human malaria in Africa. Several transcriptionally active TE families belonging both to Class I and II were identified and characterized. Interestingly, we have identified a full-length putative active element (including the presence of full length TIRs in the genomic sequence) belonging to the hAT superfamily, which presents active members in other insect genomes. This work contributes to a comprehensive understanding of the landscape of transposable elements in A. funestus transcriptome. Our results reveal that TEs are abundant and diverse in the mosquito and that most of the TE families found in the genome are represented in the mosquito transcriptome, a fact that could indicate activity of these elements.The vast diversity of TEs expressed in A. funestus suggests that there is ongoing amplification of several families in this organism.

  17. Infinte Periodic Structure of Lightweight Elements

    DEFF Research Database (Denmark)

    Domadiya, Parthkumar Gandalal; Andersen, Lars Vabbersgaard; Sorokin, Sergey

    2013-01-01

    . Furthermore, lightweight building elements are typically periodic structures that behave as filters for sound propagation within certain frequency ranges (stop bands), thus only allowing transmission within the pass bands. Hence, traditional methods based on statistical energy analysis cannot be used...... for proper dynamic assessment of lightweight buildings. Instead, this paper discusses and compares the use of finite element analysis and a wave approach based on Floquet theory. The present analysis has focus on the effect of periodicity on vibration transmission within semi-infinite beam structures. Two...... models of a semi-infinite Euler-Bernoulli and Timoshenko beam structure with periodic variation of the cross-sectional properties are analyzed. In case of the Euler-Bernoulli beam, vibrational behavior is studied in two dimensions by finite element analysis and Floquet theory. Wave propagation within...

  18. Matrix elements from moments of correlation functions

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chia Cheng [SLAC National Accelerator Lab., Menlo Park, CA (United States); Bouchard, Chris [College of William and Mary, Williamsburg, VA (United States); Orginos, Konstantinos [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); College of William and Mary, Williamsburg, VA (United States); Richards, David G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-10-01

    Momentum-space derivatives of matrix elements can be related to their coordinate-space moments through the Fourier transform. We derive these expressions as a function of momentum transfer Q2 for asymptotic in/out states consisting of a single hadron. We calculate corrections to the finite volume moments by studying the spatial dependence of the lattice correlation functions. This method permits the computation of not only the values of matrix elements at momenta accessible on the lattice, but also the momentum-space derivatives, providing {\\it a priori} information about the Q2 dependence of form factors. As a specific application we use the method, at a single lattice spacing and with unphysically heavy quarks, to directly obtain the slope of the isovector form factor at various Q2, whence the isovector charge radius. The method has potential application in the calculation of any hadronic matrix element with momentum transfer, including those relevant to hadronic weak decays.

  19. Trace element changes in cardiovascular diseases

    Science.gov (United States)

    Pinheiro, T.; Fernandes, R.; Maenhaut, W.; Hebbrecht, G.; Wätjen, U.; Halpern, M. J.

    1993-04-01

    Artery samples and five different brain structures originating from both atherosclerosis affected and healthy Portuguese individuals were examined for their elemental content. Particle-induced X-ray emission (PIXE) was used to determine K, Ca, Mn, Fe, Cu, Zn, Se and Rb in all the tissues studied. The most prominent differences between the pathological and reference data were those for Mn, Fe, Cu and Zn in the nucleus caudatus, putamen and substantia nigra brain regions. In the arteries a significant increase in Ca and Mn content was observed, whereas the K and Fe content declined. The decreased K and Rb content in the five brain structures from the pathological group and the changes for Mn in the nucleus caudatus, putamen and substantia nigra regions can be associated with aging. However, age cannot explain the other trace element alterations, e.g., for Fe, Cu and Zn. Most likely, the changes for these elements are due to atherosclerosis progression.

  20. Pastorale elemente in Hebreërs

    Directory of Open Access Journals (Sweden)

    C.J.H. Venter

    2010-07-01

    Full Text Available Pastoral elements in Hebrews In this article the letter to the Hebrews is scrutinised in order to investigate possible elements that can be applied in pastoral care and ministering. After indicating certain expressions used for different nuances of proclaiming in Hebrews, the expression “parakalein” as central concept for pastoral care will be focused on. The spectrum of the ensuing research includes aspects like the great High Priest’s purification of sin as foundation for pastoral care, and sympathy and empathy in the work of the great High Priest. Furthermore, viewpoints on the following are given: a pastoral relationship, the Hebrew term, “therapon”, as specific expression for a caring minister; the instruction to the members of the congregation to be pastors for one another; spirituality, and possible indications of the meaning of suffering. Finally the pastoral elements of faith, hope and perseverance are discussed. In conclusion a summary of the most important pastoral elemens is given.

  1. Fundamental aspects of nuclear reactor fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Olander, D.R.

    1976-01-01

    The book presented is designed to function both as a text for first-year graduate courses in nuclear materials and as a reference for workers involved in the materials design and performance aspects of nuclear power plants. The contents are arranged under the following chapter headings: statistical thermodynamics, thermal properties of solids, crystal structures, cohesive energy of solids, chemical equilibrium, point defects in solids, diffusion in solids, dislocations and grain boundaries, equation of state of UO/sub 2/, fuel element thermal performance, fuel chemistry, behavior of solid fission products in oxide fuel elements, swelling due to fission gases, pore migration and fuel restructuring kinetics, fission gas release, mechanical properties of UO/sub 2/, radiation damage, radiation effects in metals, interaction of sodium and stainless steel, modeling of the structural behavior of fuel elements and assemblies. (DG)

  2. Transposable Elements: No More 'Junk DNA'

    Directory of Open Access Journals (Sweden)

    Yun-Ji Kim

    2012-12-01

    Full Text Available Since the advent of whole-genome sequencing, transposable elements (TEs, just thought to be 'junk' DNA, have been noticed because of their numerous copies in various eukaryotic genomes. Many studies about TEs have been conducted to discover their functions in their host genomes. Based on the results of those studies, it has been generally accepted that they have a function to cause genomic and genetic variations. However, their infinite functions are not fully elucidated. Through various mechanisms, including de novo TE insertions, TE insertion-mediated deletions, and recombination events, they manipulate their host genomes. In this review, we focus on Alu, L1, human endogenous retrovirus, and short interspersed element/variable number of tandem repeats/Alu (SVA elements and discuss how they have affected primate genomes, especially the human and chimpanzee genomes, since their divergence.

  3. Major and trace elements in lithogenesis.

    Science.gov (United States)

    Słojewski, Marcin

    2011-01-01

    The process of crystallization in the urinary tract occurs when the equilibrium between promoting and inhibiting factors is broken. Many theories have been published to explain the mechanism of urinary stones formation; however, none of these theories has paid attention to trace elements. Their role in lithogenesis is still unclear and under debate. The findings of some studies may support the thesis that some major and trace elements may take part in the initiation of stone crystallization for instance as a nucleus or nidus for the formation of the stone, or simply contaminate the stone structure. This review presents a comprehensive account of the basic principles of the basic data and the role of major and trace elements in lithogenesis.

  4. Fractional Order Element Based Impedance Matching

    KAUST Repository

    Radwan, Ahmed Gomaa

    2014-06-24

    Disclosed are various embodiments of methods and systems related to fractional order element based impedance matching. In one embodiment, a method includes aligning a traditional Smith chart (|.alpha.|=1) with a fractional order Smith chart (|.alpha.|.noteq.1). A load impedance is located on the traditional Smith chart and projected onto the fractional order Smith chart. A fractional order matching element is determined by transitioning along a matching circle of the fractional order Smith chart based at least in part upon characteristic line impedance. In another embodiment, a system includes a fractional order impedance matching application executed in a computing device. The fractional order impedance matching application includes logic that obtains a first set of Smith chart coordinates at a first order, determines a second set of Smith chart coordinates at a second order, and determines a fractional order matching element from the second set of Smith chart coordinates.

  5. Heavy-element chemistry - Status and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Tuerler, A. [Paul Scherrer Institut, Villigen (Switzerland); Bern univ. (Switzerland)

    2002-10-01

    In the past ten years, nuclear chemists have made considerable progress in developing fast on-line separation techniques, which allowed to chemically characterize the first four transactinide elements Rf (rutherfordium, Z=104), Db (dubnium, Z=105), Sg (seaborgium, Z=106), and recently also Bh (bohrium, Z=107). In all cases the isolated nuclides were unambiguously identified by observing genetically linked decay chains. Nuclides with production cross-sections of less than 100 pb and half-lives as short as a few seconds have been chemically isolated. Thus, chemists have discovered or significantly contributed to the characterization of the nuclear-decay properties of a number of transactinide nuclei. New techniques with greatly improved overall efficiencies should allow chemists to extend their studies to even heavier elements such as Hs (hassium, Z=108) and to the recently discovered superheavy elements with Z=112 and 114, which can be produced only with picobarn cross-sections. (orig.)

  6. Finite-Element Software for Conceptual Design

    DEFF Research Database (Denmark)

    Lindemann, J.; Sandberg, G.; Damkilde, Lars

    2010-01-01

    Using finite-element analysis in conceptual design and teaching has quite different software requirements to that in engineering and research. In teaching and conceptual design the focus is on speed, interactivity and ease of use, whereas accuracy and precision are needed in engineering...... and research. Forcepad is an effort to provide a conceptual design and teaching tool in a finite-element software package. Forcepad is a two-dimensional finite-element application based on the same conceptual model as image editing applications such as Adobe Photoshop or Microsoft Paint. Instead of using...... success in teaching as well as in conceptual design environments such as architecture, industrial design and engineering. The addition of an optimisation algorithm and tablet PC support makes the software even more interesting as a tool for conceptual design....

  7. Finite Element Methods and Their Applications

    CERN Document Server

    Chen, Zhangxin

    2005-01-01

    This book serves as a text for one- or two-semester courses for upper-level undergraduates and beginning graduate students and as a professional reference for people who want to solve partial differential equations (PDEs) using finite element methods. The author has attempted to introduce every concept in the simplest possible setting and maintain a level of treatment that is as rigorous as possible without being unnecessarily abstract. Quite a lot of attention is given to discontinuous finite elements, characteristic finite elements, and to the applications in fluid and solid mechanics including applications to porous media flow, and applications to semiconductor modeling. An extensive set of exercises and references in each chapter are provided.

  8. Diffractive elements performance in chromatic confocal microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Garzon, J; Duque, D; Alean, A; Toledo, M [Grupo de Optica y EspectroscopIa, Centro de Ciencia Basica, Universidad Pontificia Bolivariana. Medellin (Colombia); Meneses, J [Laboratorio de Optica y Tratamiento de Senales, Instituto de Fisica, Universidad Industrial de Santander, Bucaramanga (Colombia); Gharbi, T, E-mail: jgarzonr10@une.net.co [Laboratoire d' Optique P. M. Duffieux, UMR-6603 CNR/Universite de Franche-Comte. 16 route de Gray, 25030 Besancon Cedex (France)

    2011-01-01

    The Confocal Laser Scanning Microscopy (CLSM) has been widely used in the semiconductor industry and biomedicine because of its depth discrimination capability. Subsequent to this technique has been developed in recent years Chromatic Confocal Microscopy. This method retains the same principle of confocal and offers the added advantage of removing the axial movement of the moving system. This advantage is usually accomplished with an optical element that generates a longitudinal chromatic aberration and a coding system that relates the axial position of each point of the sample with the wavelength that is focused on each. The present paper shows the performance of compact chromatic confocal microscope when some different diffractive elements are used for generation of longitudinal chromatic aberration. Diffractive elements, according to the process and manufacturing parameters, may have different diffraction efficiency and focus a specific wavelength in a specific focal position. The performance assessment is carried out with various light sources which exhibit an incoherent behaviour and a broad spectral width.

  9. Nanoscience and nanotechnology of f elements

    Energy Technology Data Exchange (ETDEWEB)

    Felinto, Maria Claudia F.C. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: mfelinto@ipen.br; Brito, Hermi F. [Sao Paulo Univ., SP (Brazil). Inst. de Quimica]. E-mail: hefbrito@iq.usp.br

    2005-07-01

    Medicaments that are carried via blood flow to sick organs; an electronic equipment capable of evaluating quality of beverages twice more sensitive than the human palate; magnets inside plastic micro-spheres that could help remove oil stains from the sea. Products that seem to have been taken from science fiction films, things that could never be part of our grandfather's imagination, they are actually the marvels of one more technological revolution: the nanotechnology. In this context, lanthanides and actinides elements play a fundamental role due to their singular chemical and physical properties. They appear as fundamental materials in a large range of areas such as, new materials applied to fuel element, sensors, electronics, drugs and markers (radio isotope), probes etc. The aim of this work is to review the chemistry and physics properties of these elements approaching this new technology point of view, emphasizing their nuclear applications. (author)

  10. Male germline control of transposable elements.

    Science.gov (United States)

    Bao, Jianqiang; Yan, Wei

    2012-05-01

    Repetitive sequences, especially transposon-derived interspersed repetitive elements, account for a large fraction of the genome in most eukaryotes. Despite the repetitive nature, these transposable elements display quantitative and qualitative differences even among species of the same lineage. Although transposable elements contribute greatly as a driving force to the biological diversity during evolution, they can induce embryonic lethality and genetic disorders as a result of insertional mutagenesis and genomic rearrangement. Temporary relaxation of the epigenetic control of retrotransposons during early germline development opens a risky window that can allow retrotransposons to escape from host constraints and to propagate abundantly in the host genome. Because germline mutations caused by retrotransposon activation are heritable and thus can be deleterious to the offspring, an adaptive strategy has evolved in host cells, especially in the germline. In this review, we will attempt to summarize general defense mechanisms deployed by the eukaryotic genome, with an emphasis on pathways utilized by the male germline to confer retrotransposon silencing.

  11. Elemental composition of arctic particulate matter

    Science.gov (United States)

    Cahill, T. A.; Eldred, R. A.

    1984-01-01

    Measurements were made of the elemental composition of particulate matter collected in flights in the Arctic in spring 1983 as part of the Arctic Gas and Aerosol Sampling Program (AGASP). Ten samples of size-selected particles were analyzed by four nondestructive techniques at Davis. Concentrations were determined for H, C, N, and O by Forward Alpha Scattering Techniques (FAST) and for elements heavier than fluorine by Particle Induced X-ray Emission (PIXE). Total mass was measured gravimetrically, and optical absorption was measured using the Laser Integrating Plate Method (LIPM). Results of the analyses show dramatic differences in concentrations and elemental ratios from the Alaskan Arctic to the Norwegian Arctic, with indications of wood smoke and sulfuric acid in the arctic atmosphere.

  12. NEUTRONIC REACTOR FUEL ELEMENT AND CORE SYSTEM

    Science.gov (United States)

    Moore, W.T.

    1958-09-01

    This patent relates to neutronic reactors and in particular to an improved fuel element and a novel reactor core system for facilitating removal of contaminating fission products, as they are fermed, from association with the flssionable fuel, so as to mitigate the interferent effects of such fission products during reactor operation. The fuel elements are comprised of tubular members impervious to fluid and contatning on their interior surfaces a thin layer of fissionable material providing a central void. The core structure is comprised of a plurality of the tubular fuel elements arranged in parallel and a closed manifold connected to their ends. In the reactor the core structure is dispersed in a water moderator and coolant within a pressure vessel, and a means connected to said manifuld is provided for withdrawing and disposing of mobile fission product contamination from the interior of the feel tubes and manifold.

  13. Frontiers of heavy element nuclear and radiochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, D.C.

    1997-10-01

    The production and half-lives of the heaviest chemical elements, now known through Z = 112, are reviewed. Recent experimental evidence for the stabilization of heavy element isotopes due to proximity to deformed nuclear shells at Z = 108 and N = 162 is compared with the theoretical predictions. The possible existence of isotopes of elements 107--110 with half-lives of seconds or longer, and production reactions and experimental techniques for increasing the overall yields of such isotopes in order to study both their nuclear and chemical properties are discussed. The present status of studies of the chemical properties of Rf, Ha, and Sg is briefly summarized and prospects for extending chemical studies beyond Sg are considered.

  14. Finite elements for analysis and design

    CERN Document Server

    Akin, J E; Davenport, J H

    1994-01-01

    The finite element method (FEM) is an analysis tool for problem-solving used throughout applied mathematics, engineering, and scientific computing. Finite Elements for Analysis and Design provides a thoroughlyrevised and up-to-date account of this important tool and its numerous applications, with added emphasis on basic theory. Numerous worked examples are included to illustrate the material.Key Features* Akin clearly explains the FEM, a numerical analysis tool for problem-solving throughout applied mathematics, engineering and scientific computing* Basic theory has bee

  15. Structural elements design manual working with Eurocodes

    CERN Document Server

    Draycott, Trevor

    2009-01-01

    Structural Elements Design Manual: Working With Eurocodes is the structural engineers 'companion volume' to the four Eurocodes on the structural use of timber, concrete, masonry and steelwork. For the student at higher technician or first degree level it provides a single source of information on the behaviour and practical design of the main elements of the building structure. With plenty of worked examples and diagrams, it is a useful textbook not only for students of structural and civil engineering, but also for those on courses in related subjects such as

  16. Elemental microanalysis in ecophysiology using ion microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Przybylowicz, W.J. E-mail: przybylowicz@tlabs.ac.za; Mesjasz-Przybylowicz, J.; Migula, P.; Turnau, K.; Nakonieczny, M.; Augustyniak, M.; Glowacka, E

    2004-06-01

    A few recent applications of elemental microanalysis based on proton beam in ecophysiology and ecotoxicology are shown. They are related to biofiltering capabilities of mycorrhiza (symbiosis between fungi and plant roots) and to plant-insect herbivore interactions. The reported results were obtained at iThemba LABS, South Africa. PIXE and BS techniques were simultaneously used. True elemental maps were generated using a VMS version and PC version of GeoPIXE (GeoPIXE I and II). Further analysis was performed using PIXE and BS spectra extracted from list-mode data and corresponding to specific organs of an insect or a plant.

  17. CHEMICAL ELEMENTS IN SOME EDIBLE PLANTS

    OpenAIRE

    Rodríguez Pichiling, C.E.; Facultad de Química e Ingeniería Química Instituto de Ciencias Químicas,Universidad Nacional Mayor de San Marcos,Lima,Perú.

    2014-01-01

    Qualitative analysis of some Peruvian plant foods is presented because it contains chemicals. Spectrographic method using optical atomic emission technique and normal electric arc carbon electrodes has been able to detect so-called "macro elements" and "trace elements", with the latter in the form of traces. (About 14 items ). Se presenta el análisis cualitativo de algunos alimentos vegetales peruanos, por su contenido en elementos químicos. Empleando el método espectrográfico de emisión a...

  18. Spectroscopy of element 115 decay chains.

    Science.gov (United States)

    Rudolph, D; Forsberg, U; Golubev, P; Sarmiento, L G; Yakushev, A; Andersson, L-L; Di Nitto, A; Düllmann, Ch E; Gates, J M; Gregorich, K E; Gross, C J; Heßberger, F P; Herzberg, R-D; Khuyagbaatar, J; Kratz, J V; Rykaczewski, K; Schädel, M; Åberg, S; Ackermann, D; Block, M; Brand, H; Carlsson, B G; Cox, D; Derkx, X; Eberhardt, K; Even, J; Fahlander, C; Gerl, J; Jäger, E; Kindler, B; Krier, J; Kojouharov, I; Kurz, N; Lommel, B; Mistry, A; Mokry, C; Nitsche, H; Omtvedt, J P; Papadakis, P; Ragnarsson, I; Runke, J; Schaffner, H; Schausten, B; Thörle-Pospiech, P; Torres, T; Traut, T; Trautmann, N; Türler, A; Ward, A; Ward, D E; Wiehl, N

    2013-09-13

    A high-resolution α, x-ray, and γ-ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum für Schwerionenforschung. Thirty correlated α-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z=115. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z>112. Comprehensive Monte Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.

  19. Lumped elements for RF and microwave circuits

    CERN Document Server

    Bahl, Inder

    2003-01-01

    Due to the unprecedented growth in wireless applications over the past decade, development of low-cost solutions for RF and microwave communication systems has become of great importance. This practical new book is the first comprehensive treatment of lumped elements, which are playing a critical role in the development of the circuits that make these cost-effective systems possible. The books offers you an in-depth understanding of the different types of RF and microwave circuit elements, including inductors, capacitors, resistors, transformers, via holes, airbridges, and crossovers. Support

  20. Book review. Antonio Sandu: Elemente de sociologie

    Directory of Open Access Journals (Sweden)

    Stefan Vladutescu

    2014-12-01

    Full Text Available Appreciated specialist in the social sciences domain and of the sociohuman sciences, Professor Antonio Sandu posted at Tritonic Publishing a remarkable book, "Elements of sociology" (Bucharest, Tritonic Publishing, 2014 (Antonio Sandu (2014. Elemente de sociologie. Bucuresti: Editura Tritonic. This represents an introduction to the theory of social phenomena. What performs first of all the value and originality of the research in question is shown to be: a the comprehension and interpretation of the social, i.e. social hermeneutics, and b the novelty of the postmodern and transmodern perspective of methodological, transdisciplinary and constructivist approach.