Potential-model calculation of an order-v2 nonrelativistic QCD matrix element
NASA Astrophysics Data System (ADS)
Bodwin, Geoffrey T.; Kang, Daekyoung; Lee, Jungil
2006-07-01
We present two methods for computing dimensionally regulated nonrelativistic QCD heavy-quarkonium matrix elements that are related to the second derivative of the heavy-quarkonium wave function at the origin. The first method makes use of a hard-cutoff regulator as an intermediate step and requires knowledge only of the heavy-quarkonium wave function. It involves a significant cancellation that is an obstacle to achieving high numerical accuracy. The second method is more direct and yields a result that is identical to the Gremm-Kapustin relation, but it is limited to use in potential models. It can be generalized to the computation of matrix elements of higher order in the heavy-quark velocity and can be used to resum the contributions to decay and production rates that are associated with those matrix elements. We apply these methods to the Cornell potential model and compute a matrix element for the J/ψ state that appears in the leading relativistic correction to the production and decay of that state through the color-singlet quark-antiquark channel.
NASA Astrophysics Data System (ADS)
Alborzpour, Jonathan P.; Tew, David P.; Habershon, Scott
2016-11-01
Solution of the time-dependent Schrödinger equation using a linear combination of basis functions, such as Gaussian wavepackets (GWPs), requires costly evaluation of integrals over the entire potential energy surface (PES) of the system. The standard approach, motivated by computational tractability for direct dynamics, is to approximate the PES with a second order Taylor expansion, for example centred at each GWP. In this article, we propose an alternative method for approximating PES matrix elements based on PES interpolation using Gaussian process regression (GPR). Our GPR scheme requires only single-point evaluations of the PES at a limited number of configurations in each time-step; the necessity of performing often-expensive evaluations of the Hessian matrix is completely avoided. In applications to 2-, 5-, and 10-dimensional benchmark models describing a tunnelling coordinate coupled non-linearly to a set of harmonic oscillators, we find that our GPR method results in PES matrix elements for which the average error is, in the best case, two orders-of-magnitude smaller and, in the worst case, directly comparable to that determined by any other Taylor expansion method, without requiring additional PES evaluations or Hessian matrices. Given the computational simplicity of GPR, as well as the opportunities for further refinement of the procedure highlighted herein, we argue that our GPR methodology should replace methods for evaluating PES matrix elements using Taylor expansions in quantum dynamics simulations.
Relativistic Dipole Matrix Element Zeros
NASA Astrophysics Data System (ADS)
Lajohn, L. A.; Pratt, R. H.
2002-05-01
There is a special class of relativistic high energy dipole matrix element zeros (RZ), whose positions with respect to photon energy ω , only depend on the bound state l quantum number according to ω^0=mc^2/(l_b+1) (independent of primary quantum number n, nuclear charge Z, central potential V and dipole retardation). These RZ only occur in (n,l_b,j_b)arrow (ɛ , l_b+1,j_b) transitions such as ns_1/2arrow ɛ p_1/2; np_3/2arrow ɛ d_3/2: nd_5/2arrow ɛ f_5/2 etc. The nonrelativistic limit of these matrix elements can be established explicitly in the Coulomb case. Within the general matrix element formalism (such as that in [1]); when |κ | is substituted for γ in analytic expressions for matrix elements, the zeros remain, but ω^0 now becomes dependent on n and Z. When the reduction to nonrelativistic form is completed by application of the low energy approximation ω mc^2 mc^2, the zeros disappear. This nonzero behavior was noted in nonrelativistic dipole Coulomb matrix elements by Fano and Cooper [2] and later proven by Oh and Pratt[3]. (J. H. Scofield, Phys. Rev. A 40), 3054 (1989 (U. Fano and J. W. Cooper, Rev. Mod. Phys. 40), 441 (1968). (D. Oh and R. H. Pratt, Phys. Rev. A 34), 2486 (1986); 37, 1524 (1988); 45, 1583 (1992).
Parrish, Robert M; Hohenstein, Edward G; Schunck, Nicolas F; Sherrill, C David; Martínez, Todd J
2013-09-27
Configuration-space matrix elements of N-body potentials arise naturally and ubiquitously in the Ritz-Galerkin solution of many-body quantum problems. For the common specialization of local, finite-range potentials, we develop the exact tensor hypercontraction method, which provides a quantized renormalization of the coordinate-space form of the N-body potential, allowing for a highly separable tensor factorization of the configuration-space matrix elements. This representation allows for substantial computational savings in chemical, atomic, and nuclear physics simulations, particularly with respect to difficult "exchangelike" contractions.
Matrix elements from moments of correlation functions
Chang, Chia Cheng; Bouchard, Chris; Orginos, Konstantinos; Richards, David G.
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.
NASA Astrophysics Data System (ADS)
Gu, Jian-ping; Buenker, Robert J.; Hirsch, Gerhard; Kimura, Mineo
1995-05-01
Ab initio multireference CI calculations have been carried out for the HeN+ molecular ion in order to describe collision processes between its constituent neutral and ionized atoms. The accuracy of these calculations is evaluated by means of a comparison of results obtained at large internuclear separations with the corresponding asymptotic energies deduced from atomic spectral data. Energy values are computed for the eleven lowest He++N and He+N+ atomic limits and average discrepancies relative to the experimental excitation energies up to 110 000 cm-1 are found to lie in the 1000-3000 cm-1 range, of which only 200 cm-1 appears to be the fault of the configuration interaction (CI) technique itself, with the main portion of the error stemming from the choice of atomic orbital (AO) basis instead. The HeN+ X 3Σ- ground state is calculated to have a De value of only 1414 cm-1, but the excited 2 3Π state has a much larger value of 22 133 cm-1 by virtue of an avoided crossing with the lower state of this symmetry. The corresponding radial nonadiabatic coupling is responsible for a large cross section for an excitation process between the N+(3Pg)+He and N+(3Du)+He channels which indirectly provides an efficient electron-capture mechanism leading to the N(4Su)+He+ exit channel. Additional nonadiabatic matrix elements for rotational and spin-orbit coupling have also been obtained and analyzed, as well as transition moments between the various HeN+ molecular states calculated.
NASA Astrophysics Data System (ADS)
Chuluunbaatar, O.; Gusev, A. A.; Gerdt, V. P.; Rostovtsev, V. A.; Vinitsky, S. I.; Abrashkevich, A. G.; Kaschiev, M. S.; Serov, V. V.
2008-02-01
A FORTRAN 77 program is presented which calculates with the relative machine precision potential curves and matrix elements of the coupled adiabatic radial equations for a hydrogen-like atom in a homogeneous magnetic field. The potential curves are eigenvalues corresponding to the angular oblate spheroidal functions that compose adiabatic basis which depends on the radial variable as a parameter. The matrix elements of radial coupling are integrals in angular variables of the following two types: product of angular functions and the first derivative of angular functions in parameter, and product of the first derivatives of angular functions in parameter, respectively. The program calculates also the angular part of the dipole transition matrix elements (in the length form) expressed as integrals in angular variables involving product of a dipole operator and angular functions. Moreover, the program calculates asymptotic regular and irregular matrix solutions of the coupled adiabatic radial equations at the end of interval in radial variable needed for solving a multi-channel scattering problem by the generalized R-matrix method. Potential curves and radial matrix elements computed by the POTHMF program can be used for solving the bound state and multi-channel scattering problems. As a test desk, the program is applied to the calculation of the energy values, a short-range reaction matrix and corresponding wave functions with the help of the KANTBP program. Benchmark calculations for the known photoionization cross-sections are presented. Program summaryProgram title:POTHMF Catalogue identifier:AEAA_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAA_v1_0.html Program obtainable from:CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions:Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.:8123 No. of bytes in distributed program, including test data
Analytic Matrix Elements and Gradients with Shifted Correlated Gaussians
NASA Astrophysics Data System (ADS)
Fedorov, D. V.
2017-01-01
Matrix elements between shifted correlated Gaussians of various potentials with several form-factors are shown to be analytic. Their gradients with respect to the non-linear parameters of the Gaussians are also analytic. Analytic matrix elements are of importance for the correlated Gaussian method in quantum few-body physics.
Comix, a New Matrix Element Generator
Gleisberg, Tanju; Hoche, Stefan; /Durham U., IPPP
2008-09-03
We present a new tree-level matrix element generator, based on the color dressed Berends-Giele recursive relations. We discuss two new algorithms for phase space integration, dedicated to be used with large multiplicities and color sampling.
Semiclassical matrix elements from periodic orbits
NASA Technical Reports Server (NTRS)
Eckhardt, B.; Fishman, S.; Mueller, K.; Wintgen, D.
1992-01-01
An extension of Gutzwiller's (1967, 1969, 1970, 1971, 1990) semiclassical theory for chaotic systems that allows a determination of matrix elements in terms of classical periodic orbits. Associated zeta functions are derived. The semiclassical predictions are found to be in good agreement with Fourier transforms of quantum spectra of hydrogen in a magnetic field. Expressions for off-diagonal matrix elements are derived that are extensions of the Bohr correspondence relations for integrable systems.
Rolling Element Bearing Stiffness Matrix Determination (Presentation)
Guo, Y.; Parker, R.
2014-01-01
Current theoretical bearing models differ in their stiffness estimates because of different model assumptions. In this study, a finite element/contact mechanics model is developed for rolling element bearings with the focus of obtaining accurate bearing stiffness for a wide range of bearing types and parameters. A combined surface integral and finite element method is used to solve for the contact mechanics between the rolling elements and races. This model captures the time-dependent characteristics of the bearing contact due to the orbital motion of the rolling elements. A numerical method is developed to determine the full bearing stiffness matrix corresponding to two radial, one axial, and two angular coordinates; the rotation about the shaft axis is free by design. This proposed stiffness determination method is validated against experiments in the literature and compared to existing analytical models and widely used advanced computational methods. The fully-populated stiffness matrix demonstrates the coupling between bearing radial, axial, and tilting bearing deflections.
Renormalon ambiguities in NRQCD operator matrix elements
NASA Astrophysics Data System (ADS)
Bodwin, Geoffrey T.; Chen, Yu-Qi
1999-09-01
We analyze the renormalon ambiguities that appear in factorization formulas in QCD. Our analysis contains a simple argument that the ambiguities in the short-distance coefficients and operator matrix elements are artifacts of dimensional-regularization factorization schemes and are absent in cutoff schemes. We also present a method for computing the renormalon ambiguities in operator matrix elements and apply it to a computation of the ambiguities in the matrix elements that appear in the NRQCD factorization formulas for the annihilation decays of S-wave quarkonia. Our results, combined with those of Braaten and Chen for the short-distance coefficients, provide an explicit demonstration that the ambiguities cancel in the physical decay rates. In addition, we analyze the renormalon ambiguities in the Gremm-Kapustin relation and in various definitions of the heavy-quark mass.
The MOON project and DBD matrix elements
NASA Astrophysics Data System (ADS)
Ejiri, H.
2009-06-01
This is a brief report on experimental studies of double beta decays (DBD) in Japan, the MOON project for spectroscopic studies of neutrino-less DBD (0vββ) and on experimental studies of DBD nuclear matrix elements. Experimental DBD studies in Japan were made by geochemical methods on 130Te, 128Te and 96Zr and by a series of ELEGANT(EL) counting methods, EL III on 76Ge, EL IV, V on 100Mo, 116Cd, and EL VI on 48Ca. Future counter experiments are MOON, CANDLES, XMASS and DCBA. The MOON project, which is based on EL V, aims at studies of the Majorana nature of the neutrino (v) and the v-mass spectrum by spectroscopic 0vββ experiments with the v-mass sensitivity of < mmv > = 100-30 meV. The MOON detector is a super ensemble of multi-layer modules, each being composed by PL scintillator plates and position-sensitive detector planes. DBD nuclear matrix elements have been studied experimentally by using charge exchange reactions. The 2-neutrino DBD matrix elements are expressed by successive single-β matrix elements through low-lying intermediate states.
Lattice QCD calculations of weak matrix elements
NASA Astrophysics Data System (ADS)
Detar, Carleton
2017-01-01
Lattice QCD has become the method of choice for calculating the hadronic environment of the electroweak interactions of quarks. So it is now an essential tool in the search for new physics beyond the Standard Model. Advances in computing power and algorithms have resulted in increasingly precise predictions and increasingly stringent tests of the Standard Model. I review results of recent calculations of weak matrix elements and discuss their implications for new physics. Supported by US NSF grant PHY10-034278.
Twisted mass QCD for weak matrix elements
NASA Astrophysics Data System (ADS)
Pena, Carlos
2006-12-01
I report on the application of tmQCD techniques to the computation of hadronic matrix elements of four-fermion operators. Emphasis is put on the computation of BK in quenched QCD performed by the ALPHA Collaboration. The extension of tmQCD strategies to the study of neutral B- meson mixing is briefly discussed. Finally, some remarks are made concerning proposals to apply tmQCD to the computation of K → ππ amplitudes.
Rovibrational matrix elements of the quadrupole moment of N2 in a solid parahydrogen matrix
NASA Astrophysics Data System (ADS)
Mishra, Adya P.; Balasubramanian, T. K.
2008-11-01
The present work pertains to the study of the rotational dynamics of N2 molecules solvated in a matrix of solid para-H2. It is shown that the mixing of the rotational states due to the anisotropic part of the N2-H2 pair potential in the solid gives rise to an additional 5.4% contribution to the intensity of quadrupole-induced double transitions involving N2-H2 pair. Hence the recently reported quadrupole moment matrix element of N2 in a solid para-H2 crystal [A. P. Mishra and T. K. Balasubramanian, J. Chem. Phys. 125, 124507 (2006)], which was deduced from a comparison of the theoretical intensity (with rotational mixing of states neglected) with the measured value is larger by ˜2.7%. The ground electronic state rovibrational matrix elements ⟨v'J'|Q2(r)|vJ⟩ of N2 molecule in a solid parahydrogen matrix for v,v'≤1 and J,J'≤4 have also been computed by taking into account the changes in the intramolecular potential of N2 due to the intermolecular interaction in the matrix. The computed quadrupole moment matrix elements agree well with a few available values (for v =v'=0) deduced from the observed transitions.
Measuring Sparticles with the Matrix Element
Alwall, Johan; Freitas, Ayres; Mattelaer, Olivier; /INFN, Rome3 /Rome III U. /Louvain U.
2012-04-10
We apply the Matrix Element Method (MEM) to mass determination of squark pair production with direct decay to quarks and LSP at the LHC, showing that simultaneous mass determination of squarks and LSP is possible. We furthermore propose methods for inclusion of QCD radiation effects in the MEM. The goal of the LHC at CERN, scheduled to start this year, is to discover new physics through deviations from the Standard Model (SM) predictions. After discovery of deviations from the SM, the next step will be classification of the new physics. An important first goal in this process will be establishing a mass spectrum of the new particles. One of the most challenging scenarios is pair-production of new particles which decay to invisible massive particles, giving missing energy signals. Many methods have been proposed for mass determination in such scenarios (for a recent list of references, see e.g. [1]). In this proceeding, we report the first steps in applying the Matrix Element Method (MEM) in the context of supersymmetric scenarios giving missing energy signals. After a quick review of the MEM, we will focus on squark pair production, a process where other mass determination techniques have difficulties to simultaneously determine the LSP and squark masses. Finally, we will introduce methods to extend the range of validity of the MEM, by taking into account initial state radiation (ISR) in the method.
Precision Measurement of Transition Matrix Elements via Light Shift Cancellation
2012-12-14
vanishes, provide precise constraints on the matrix elements. We make the fhstmeasurement of the 5s-6p matrix elements in rubidium by measuring the...We make the first measurement of the 5s-6p matrix elements in rubidium by measuring the light shift around the 421 and 423 nm zeros through...elements in rubidium by measuring the light shift around the 421 and 423 nm zeros through diffraction of a condensate off a sequence of standing wave
Microscopic method for E 0 transition matrix elements
NASA Astrophysics Data System (ADS)
Brown, B. A.; Garnsworthy, A. B.; Kibédi, T.; Stuchbery, A. E.
2017-01-01
We present a microscopic model for electric monopole (E 0 ) transition matrix elements by combining a configuration interaction model for orbital occupations with an energy-density functional model for the single-particle potential and radial wave functions. The configuration interaction model is used to constrain the orbital occupations for the diagonal and off-diagonal matrix elements. These are used in an energy-density functional calculation to obtain a self-consistent transition density. This density contains the valence contribution, as well as the polarization of the protons by the valence protons and neutrons. We show connections between E 0 matrix elements and isomer and isotope shifts of the charge radius. The spin-orbit correction to the charge density is important in some cases. This model accounts for a large part of the data over a wide region of the nuclear chart. It also accounts for the shape of the observed electron scattering form factors. The results depend on the Skyrme parameters used for the energy-density functional and might be used to provide new constraints for them.
Useful extremum principle for the variational calculation of matrix elements
NASA Technical Reports Server (NTRS)
Gerjuoy, E.; Rau, A. R. P.; Rosenberg, L.; Spruch, L.
1974-01-01
Variational principles are considered for the approximate evaluation of the diagonal matrix elements of an arbitrary known linear Hermitian operator. A method is derived that is immediately applicable to the variational determination of both the off-diagonal and diagonal matrix elements of normal and modified Green's functions.
Rotordynamic Analysis with Shell Elements for the Transfer Matrix Method
1989-08-01
jACCESSION NO. 11. TITLE (Include Security Classification) (UNCLASSIFIED) ROTORDYNAMIC ANALYSIS WITH SHELL ELEMENTS FOR THE TRANSFER MATRIX METHOD 12...SECURITY CLASSIFICATION OF THIS PAGE AFIT/CI "OVERPRINT" iii ABSTRACT Rotordynamic Analysis with Shell Elements for the Transfer Matrix Method. (August...analysts in indus- try . ’ . ," Accesiu:, For NTIS CR,4i Fi FilC TA,: [3 0. fi A-1 B I ., ,.................. ,., ROTORDYNAMIC ANALYSIS WITH SHELL ELEMENTS
Excited State Effects in Nucleon Matrix Element Calculations
Constantia Alexandrou, Martha Constantinou, Simon Dinter, Vincent Drach, Karl Jansen, Theodoros Leontiou, Dru B Renner
2011-12-01
We perform a high-statistics precision calculation of nucleon matrix elements using an open sink method allowing us to explore a wide range of sink-source time separations. In this way the influence of excited states of nucleon matrix elements can be studied. As particular examples we present results for the nucleon axial charge g{sub A} and for the first moment of the isovector unpolarized parton distribution x{sub u-d}. In addition, we report on preliminary results using the generalized eigenvalue method for nucleon matrix elements. All calculations are performed using N{sub f} = 2+1+1 maximally twisted mass Wilson fermions.
Configuration interaction matrix elements for the quantum Hall effect
NASA Astrophysics Data System (ADS)
Wooten, Rachel; Macek, Joseph
2015-03-01
In the spherical model of the quantum Hall system, the two-body matrix elements and pseudopotentials can be found analytically in terms of a general scalar pair interaction potential by expressing the pair interaction as a weighted sum over Legendre polynomials. For non-infinite systems, only a finite set of terms in the potential expansion contribute to the interactions; the contributing terms define an effective spatial potential for the system. The connection between the effective spatial potential and the pseudopotential is one-to-one for finite systems, and any completely defined model pseudopotential can be analytically inverted to give a unique corresponding spatial potential. This technique of inverting the pseudopotential to derive effective spatial potentials may be of use for developing accurate model spatial potentials for quantum Monte Carlo simulations. We demonstrate the technique and the corresponding spatial potentials for a few example model pseudopotentials. Supported by Office of Basic Energy Sciences, U.S. DOE, Grant DE-FG02-02ER15283 to the University of Tennessee.
Vanishing of dipole matrix elements at level crossings.
NASA Technical Reports Server (NTRS)
Kocher, C. A.
1972-01-01
Demonstration that the vanishing of certain coupling matrix elements at level crossings follow from angular momentum commutation relations. A magnetic dipole transition having delta M = plus or minus 1, induced near a crossing of the levels in a nonzero magnetic field, is found to have a dipole matrix element comparable to or smaller than the quotient of the level separation and the field. This result also applies in the analogous electric field electric dipole case.
NASA Astrophysics Data System (ADS)
Casimir, J. B.; Kevorkian, S.; Vinh, T.
2005-10-01
This paper describes a procedure for building the dynamic stiffness matrix of two-dimensional elements with free edge boundary conditions. The dynamic stiffness matrix is the basis of the continuous element method. Then, the formulation is used to build a Kirchhoff rectangular plate element. Gorman's method of boundary condition decomposition and Levy's series are used to obtain the strong solution of the elementary problem. A symbolic computation software partially performs the construction of the dynamic stiffness matrix from this solution. The performances of the element are evaluated from comparisons with harmonic responses of plates obtained by the finite element method.
Status and future of nuclear matrix elements for neutrinoless double-beta decay: a review
NASA Astrophysics Data System (ADS)
Engel, Jonathan; Menéndez, Javier
2017-04-01
The nuclear matrix elements that govern the rate of neutrinoless double beta decay must be accurately calculated if experiments are to reach their full potential. Theorists have been working on the problem for a long time but have recently stepped up their efforts as ton-scale experiments have begun to look feasible. Here we review past and recent work on the matrix elements in a wide variety of nuclear models and discuss work that will be done in the near future. Ab initio nuclear-structure theory, which is developing rapidly, holds out hope of more accurate matrix elements with quantifiable error bars.
Status and future of nuclear matrix elements for neutrinoless double-beta decay: a review.
Engel, Jonathan; Menéndez, Javier
2017-04-01
The nuclear matrix elements that govern the rate of neutrinoless double beta decay must be accurately calculated if experiments are to reach their full potential. Theorists have been working on the problem for a long time but have recently stepped up their efforts as ton-scale experiments have begun to look feasible. Here we review past and recent work on the matrix elements in a wide variety of nuclear models and discuss work that will be done in the near future. Ab initio nuclear-structure theory, which is developing rapidly, holds out hope of more accurate matrix elements with quantifiable error bars.
The Matrix Element Method: Past, Present, and Future
Gainer, James S.; Lykken, Joseph; Matchev, Konstantin T.; Mrenna, Stephen; Park, Myeonghun
2013-07-12
The increasing use of multivariate methods, and in particular the Matrix Element Method (MEM), represents a revolution in experimental particle physics. With continued exponential growth in computing capabilities, the use of sophisticated multivariate methods-- already common-- will soon become ubiquitous and ultimately almost compulsory. While the existence of sophisticated algorithms for disentangling signal and background might naively suggest a diminished role for theorists, the use of the MEM, with its inherent connection to the calculation of differential cross sections will benefit from collaboration between theorists and experimentalists. In this white paper, we will briefly describe the MEM and some of its recent uses, note some current issues and potential resolutions, and speculate about exciting future opportunities.
Coulomb matrix elements in multi-orbital Hubbard models
NASA Astrophysics Data System (ADS)
Bünemann, Jörg; Gebhard, Florian
2017-04-01
Coulomb matrix elements are needed in all studies in solid-state theory that are based on Hubbard-type multi-orbital models. Due to symmetries, the matrix elements are not independent. We determine a set of independent Coulomb parameters for a d-shell and an f-shell and all point groups with up to 16 elements (O h , O, T d , T h , D 6h , and D 4h ). Furthermore, we express all other matrix elements as a function of the independent Coulomb parameters. Apart from the solution of the general point-group problem we investigate in detail the spherical approximation and first-order corrections to the spherical approximation.
Computer programs for the Boltzmann collision matrix elements
NASA Astrophysics Data System (ADS)
Das, P.
1989-09-01
When the distribution function in the kinetic theory of gases is expanded in a basis of orthogonal functions, the Boltzmann collision operators can be evaluated in terms of appropriate matrix elements. These matrix elements are usually given in terms of highly complex algebraic expressions. When Burnett functions, which consist of Sonine polynomials and spherical harmonics, are used as the basis, the irreducible tensor formalism provides expressions for the matrix elements that are algebraically simple, possess high symmetry, and are computationally more economical than in any other basis. The package reported here consists of routines to compute such matrix elements in a Burnett function basis for a mixture of hard sphere gases, as also the loss integral of a Burnett mode and the functions themselves. The matrix elements involve the Clebsch-Gordan and Brody-Moshinsky coefficients, both of which are used here for unusually high values of their arguments. For the purpose of validation both coefficients are computed using two different methods. Though written for hard sphere molecules the package can, with only slight modification, be adapted to more general molecular models as well.
Acceleration of matrix element computations for precision measurements
Brandt, Oleg; Gutierrez, Gaston; Wang, M. H.L.S.; Ye, Zhenyu
2014-11-25
The matrix element technique provides a superior statistical sensitivity for precision measurements of important parameters at hadron colliders, such as the mass of the top quark or the cross-section for the production of Higgs bosons. The main practical limitation of the technique is its high computational demand. Using the example of the top quark mass, we present two approaches to reduce the computation time of the technique by a factor of 90. First, we utilize low-discrepancy sequences for numerical Monte Carlo integration in conjunction with a dedicated estimator of numerical uncertainty, a novelty in the context of the matrix element technique. We then utilize a new approach that factorizes the overall jet energy scale from the matrix element computation, a novelty in the context of top quark mass measurements. The utilization of low-discrepancy sequences is of particular general interest, as it is universally applicable to Monte Carlo integration, and independent of the computing environment.
Neutrinoless double-β decay and nuclear transition matrix elements
Rath, P. K.
2015-10-28
Within mechanisms involving the light Majorana neutrinos, squark-neutrino, Majorons, sterile neutrinos and heavy Majorana neutrino, nuclear transition matrix elements for the neutrinoless (β{sup −}β{sup −}){sub 0ν} decay of {sup 96}Zr, {sup 100}Mo, {sup 128,130}Te and {sup 150}Nd nuclei are calculated by employing the PHFB approach. Effects due to finite size of nucleons, higher order currents, short range correlations, and deformations of parent as well as daughter nuclei on the calculated matrix elements are estimated. Uncertainties in nuclear transition matrix elements within long-ranged mechanisms but for double Majoron accompanied (β{sup −}β{sup −}ϕϕ){sub 0ν} decay modes are 9%–15%. In the case of short ranged heavy Majorona neutrino exchange mechanism, the maximum uncertainty is about 35%. The maximum systematic error within the mechanism involving the exchange of light Majorana neutrino is about 46%.
Some measurements for determining strangeness matrix elements in the nucleon
Henley, E.M.; Pollock, S.J.; Ying, S.; Frederico, T.; Krein,; Williams, A.G.
1991-12-31
Some experiments to measure strangeness matrix elements of the proton are proposed. Two of these suggestions are described in some detail, namely electro-production of phi mesons and the difference between neutrino and antineutrino scattering for isospin zero targets such as deuterium.
Some measurements for determining strangeness matrix elements in the nucleon
Henley, E.M.; Pollock, S.J.; Ying, S. ); Frederico, T. , Sao Jose dos Campos, SP . Inst. de Estudos Avancados); Krein, . Inst. de Fisica Teorica); Williams, A.G. )
1991-01-01
Some experiments to measure strangeness matrix elements of the proton are proposed. Two of these suggestions are described in some detail, namely electro-production of phi mesons and the difference between neutrino and antineutrino scattering for isospin zero targets such as deuterium.
Magic wavelengths, matrix elements, polarizabilities, and lifetimes of Cs
NASA Astrophysics Data System (ADS)
Safronova, M. S.; Safronova, U. I.; Clark, Charles W.
2016-07-01
Motivated by recent interest in their applications, we report a systematic study of Cs atomic properties calculated by a high-precision relativistic all-order method. Excitation energies, reduced matrix elements, transition rates, and lifetimes are determined for levels with principal quantum numbers n ≤12 and orbital angular momentum quantum numbers l ≤3 . Recommended values and estimates of uncertainties are provided for a number of electric-dipole transitions and the electric dipole polarizabilities of the n s , n p , and n d states. We also report a calculation of the electric quadrupole polarizability of the ground state. We display the dynamic polarizabilities of the 6 s and 7 p states for optical wavelengths between 1160 and 1800 nm and identify corresponding magic wavelengths for the 6 s -7 p1 /2 and 6 s -7 p3 /2 transitions. The values of relevant matrix elements needed for polarizability calculations at other wavelengths are provided.
Calculation of transition matrix elements by nonsingular orbital transformations
NASA Astrophysics Data System (ADS)
Kývala, Mojmír
A general strategy is described for the evaluation of transition matrix elements between pairs of full class CI wave functions built up from mutually nonorthogonal molecular orbitals. A new method is proposed for the counter-transformation of the linear expansion coefficients of a full CI wave function under a nonsingular transformation of the molecular-orbital basis. The method, which consists in a straightforward application of the Cauchy-Binet formula to the definition of a Slater determinant, is shown to be simple and suitable for efficient implementation on current high-performance computers. The new method appears mainly beneficial to the calculation of miscellaneous transition matrix elements among individually optimized CASSCF states and to the re-evaluation of the CASCI expansion coefficients in Slater-determinant bases formed from arbitrarily rotated (e.g., localized or, conversely, delocalized) active molecular orbitals.
[Electron transfer between globular proteins. Evaluation of a matrix element].
Lakhno, V D; Chuev, G N; Ustinin, M N
1998-01-01
The dependence of the matrix element of the probability of interprotein electron transfer on the mutual orientation of the donor and acceptor centers and the distance between them was calculated. The calculations were made under the assumption that electron transfer proceeds mainly by a collective excitation of polaron nature, like a solvated electron state. The results obtained are consistent with experimental data and indicate the nonexponential behavior of this dependence in the case when the distance transfer is less than 20 A.
A stochastic method for computing hadronic matrix elements
Alexandrou, Constantia; Constantinou, Martha; Dinter, Simon; ...
2014-01-24
In this study, we present a stochastic method for the calculation of baryon 3-point functions which is an alternative to the typically used sequential method offering more versatility. We analyze the scaling of the error of the stochastically evaluated 3-point function with the lattice volume and find a favorable signal to noise ratio suggesting that the stochastic method can be extended to large volumes providing an efficient approach to compute hadronic matrix elements and form factors.
Disk level S-matrix elements at eikonal Regge limit
NASA Astrophysics Data System (ADS)
Garousi, Mohammad R.
2011-01-01
We examine the calculation of the color-ordered disk level S-matrix element of massless scalar vertex operators for the special case that some of the Mandelstam variables for which there are no open string channel in the amplitude, are set to zero. By explicit calculation we show that the string form factors in the 2n-point functions reduce to one at the eikonal Regge limit.
Calculating weak matrix elements using HYP staggered fermions
T. Bhattacharya; G. T. Fleming; G. Kilcup; R. Gupta; W. Lee; S. Sharpe
2004-03-01
We present preliminary results of weak matrix elements relevant to CP violation calculated using the HYP (II) staggered fermions. Since the complete set of matching coefficients at the one-loop level became available recently, we have constructed lattice operators with all the g{sup 2} corrections included. The main results include both {Delta}I = 3/2 and {Delta}I = 1/2 contributions.
Algebraic evaluation of matrix elements in the Laguerre function basis
NASA Astrophysics Data System (ADS)
McCoy, A. E.; Caprio, M. A.
2016-02-01
The Laguerre functions constitute one of the fundamental basis sets for calculations in atomic and molecular electron-structure theory, with applications in hadronic and nuclear theory as well. While similar in form to the Coulomb bound-state eigenfunctions (from the Schrödinger eigenproblem) or the Coulomb-Sturmian functions (from a related Sturm-Liouville problem), the Laguerre functions, unlike these former functions, constitute a complete, discrete, orthonormal set for square-integrable functions in three dimensions. We construct the SU(1, 1) × SO(3) dynamical algebra for the Laguerre functions and apply the ideas of factorization (or supersymmetric quantum mechanics) to derive shift operators for these functions. We use the resulting algebraic framework to derive analytic expressions for matrix elements of several basic radial operators (involving powers of the radial coordinate and radial derivative) in the Laguerre function basis. We illustrate how matrix elements for more general spherical tensor operators in three dimensional space, such as the gradient, may then be constructed from these radial matrix elements.
Weak matrix elements on the lattice - Circa 1995
Soni, A.
1995-10-03
Status of weak matrix elements is reviewed. In particular, e{prime}/e, B {yields} K*{gamma}, B{sub B} and B{sub B}, are discussed and the overall situation with respect to the lattice effort and some of its phenomenological implications are summarised. For e{prime}/e the need for the relevant matrix elements is stressed in view of the forthcoming improved experiments. For some of the operators, (e.g. O{sub 6}), even bound on their matrix elements would be very helpful. On B {yields} K{degrees}{gamma}, a constant behavior of T{sub 2} appears disfavored although dependence of T{sub 2} could, of course, be milder than a simple pole. Improved data is badly needed to settle this important issue firmly, especially in view of its ramification for extractions of V{sub td} from B {yields} {rho}{gamma}. On B{sub {kappa}}, the preliminary result from JLQCD appears to contradict Sharpe et al. JLQCD data seems to fit very well to linear {alpha} dependence and leads to an appreciably lower value of B{sub {kappa}}. Four studies of B{sub {kappa}} in the {open_quotes}full{close_quotes} (n{sub f} = 2) theory indicate very little quenching effects on B{sub {kappa}}; the full theory value seems to be just a little less than the quenched result. Based on expectations from HQET, analysis of B-parameter (B{sub h}{ell}) for the heavy-light mesons via B{sub h}{ell}) = constant + constants{prime}/m{sub h}{ell} is suggested. A summary of an illustrative sample of hadron matrix elements is given and constraints on CKM parameters (e.g. V{sub td}/V{sub ts}, on the unitarity triangle and on x{sub s}/x{sub d}, emerging from the lattice calculations along with experimental results are briefly discussed. In quite a few cases, for the first time, some indication of quenching errors on weak matrix elements are now becoming available.
Acceleration of matrix element computations for precision measurements
Brandt, Oleg; Gutierrez, Gaston; Wang, M. H.L.S.; ...
2014-11-25
The matrix element technique provides a superior statistical sensitivity for precision measurements of important parameters at hadron colliders, such as the mass of the top quark or the cross-section for the production of Higgs bosons. The main practical limitation of the technique is its high computational demand. Using the example of the top quark mass, we present two approaches to reduce the computation time of the technique by a factor of 90. First, we utilize low-discrepancy sequences for numerical Monte Carlo integration in conjunction with a dedicated estimator of numerical uncertainty, a novelty in the context of the matrix elementmore » technique. We then utilize a new approach that factorizes the overall jet energy scale from the matrix element computation, a novelty in the context of top quark mass measurements. The utilization of low-discrepancy sequences is of particular general interest, as it is universally applicable to Monte Carlo integration, and independent of the computing environment.« less
Kaon matrix elements and CP violation from quenched lattice QCD
NASA Astrophysics Data System (ADS)
Cristian, Calin-Radu
We report the results of a calculation of the K → pipi matrix elements relevant for the DeltaI = 1/2 rule and epsilon '/epsilon in quenched lattice QCD using domain wall fermions at a fixed lattice spacing of a-1 ˜ 2 GeV. Working in the three-quark effective theory, where only the u, d and s quarks enter and which is known perturbatively to next-to-leading order; we calculate the lattice K → pi and K → |0> matrix elements of dimension six, four-fermion operators. Through lowest order chiral perturbation theory these yield K → pipi matrix elements, which we then normalize to continuum values through a non-perturbative renormalization technique. For the Delta I = 1/2 rule we find a value of 25.3 +/- 1.8 (statistical error only) compared to the experimental value of 22.2, with individual isospin amplitudes 10--20% below the experimental values. For epsilon '/epsilon; using known central values for standard model parameters, we calculate (-4.0 +/- 2.3) x 10-4 (statistical error only) compared to the current experimental average of (17.2 +/- 1.8) x 10-4. Because we find a large cancellation between the I = 0 and I = 2 contributions to epsilon'/epsilon, the result may be very sensitive to the approximations employed. Among these are the use of: quenched QCD, lowest order chiral perturbation theory and continuum perturbation theory below 1.3 GeV. We have also calculated the kaon B parameter, BK and find BK(2 GeV) = 0.532(11). Although currently unable to give a reliable systematic error; we have control over statistical errors and more simulations will yield information about the effects of the approximations on this first-principles determination of these important quantities.
Weak matrix elements efforts on the lattice: Status and prospects
Soni, A.
1995-01-01
Lattice approach to weak matrix elements is reviewed. Recent progress in treating heavy quarks on the lattice is briefly discussed. Illustrative sample of results obtained so far is given. Among them I elaborate on B{sub K}, {line_integral}{sub B} and B {yields} K*{sub {gamma}}. Experimental implications especially with regard to constraints on the Standard Model (i.e. Wolfenstein) parameters, V{sub td} measurements and expectations for B{sub s}-{bar B}{sub s}, oscillations are briefly discussed.
Separable approximation to two-body matrix elements
Robledo, Luis M.
2010-04-15
Two-body matrix elements of arbitrary local interactions are written as the sum of separable terms in a way that is well suited for the exchange and pairing channels present in mean-field calculations. The expansion relies on the transformation to center of mass and relative coordinate (in the spirit of Talmi's method) and therefore it is only useful (finite number of expansion terms) for harmonic oscillator single particle states. The converge of the expansion with the number of terms retained is studied for a Gaussian two body interaction. The limit of a contact (delta) force is also considered. Ways to handle the general case are also discussed.
The Matrix Element Method in the LHC era
NASA Astrophysics Data System (ADS)
Wertz, Sébastien
2017-03-01
The Matrix Element Method (MEM) is a powerful multivariate method allowing to maximally exploit the experimental and theoretical information available to an analysis. The method is reviewed in depth, and several recent applications of the MEM at LHC experiments are discussed, such as searches for rare processes and measurements of Standard Model observables in Higgs and Top physics. Finally, a new implementation of the MEM is presented. This project builds on established phase-space parametrisations known to greatly improve the speed of the calculations, and aims at a much improved modularity and maintainability compared to previous software, easing the use of the MEM for high-statistics data analyses.
Generalized Potential Energy Finite Elements for Modeling Molecular Nanostructures.
Chatzieleftheriou, Stavros; Adendorff, Matthew R; Lagaros, Nikos D
2016-10-24
The potential energy of molecules and nanostructures is commonly calculated in the molecular mechanics formalism by superimposing bonded and nonbonded atomic energy terms, i.e. bonds between two atoms, bond angles involving three atoms, dihedral angles involving four atoms, nonbonded terms expressing the Coulomb and Lennard-Jones interactions, etc. In this work a new, generalized numerical simulation is presented for studying the mechanical behavior of three-dimensional nanostructures at the atomic scale. The energy gradient and Hessian matrix of such assemblies are usually computed numerically; a potential energy finite element model is proposed herein where these two components are expressed analytically. In particular, generalized finite elements are developed that express the interactions among atoms in a manner equivalent to that invoked in simulations performed based on the molecular dynamics method. Thus, the global tangent stiffness matrix for any nanostructure is formed as an assembly of the generalized finite elements and is directly equivalent to the Hessian matrix of the potential energy. The advantages of the proposed model are identified in terms of both accuracy and computational efficiency. In the case of popular force fields (e.g., CHARMM), the computation of the Hessian matrix by implementing the proposed method is of the same order as that of the gradient. This analysis can be used to minimize the potential energy of molecular systems under nodal loads in order to derive constitutive laws for molecular systems where the entropy and solvent effects are neglected and can be approximated as solids, such as double stranded DNA nanostructures. In this context, the sequence dependent stretch modulus for some typical base pairs step is calculated.
Closed String S-matrix Elements in Open String Field Theory
NASA Astrophysics Data System (ADS)
Garousi, Mohammad R.; Maktabdaran, G. R.
2005-03-01
We study the S-matrix elements of the gauge invariant operators corresponding to on-shell closed strings, in open string field theory. In particular, we calculate the tree level S-matrix element of two arbitrary closed strings, and the S-matrix element of one closed string and two open strings. By mapping the world-sheet of these amplitudes to the upper half z-plane, and by evaluating explicitly the correlators in the ghost part, we show that these S-matrix elements are exactly identical to the corresponding disk level S-matrix elements in perturbative string theory.
NASA Astrophysics Data System (ADS)
Craggs, A.
1989-08-01
When making an acoustic finite element model of a duct system, the resulting matrices can be very large due to the length of ductwork, the complex changes in geometry and the numerous junctions, and a full model may require several thousand nodes. In this paper two techniques are given for reducing the size of the matrices; the transfer matrix method and the condensed stiffness matrix approach—both of which lead to equations expressed in terms of the input and output nodes only. The methods are demonstrated with examples on a straight section of duct and a branched duct network. The substantial reductions in computer memory shown imply that duct acoustic problems can be studied using a desktop work station.
Kinetic-energy matrix elements for atomic Hylleraas-CI wave functions.
Harris, Frank E
2016-05-28
Hylleraas-CI is a superposition-of-configurations method in which each configuration is constructed from a Slater-type orbital (STO) product to which is appended (linearly) at most one interelectron distance rij. Computations of the kinetic energy for atoms by this method have been difficult due to the lack of formulas expressing these matrix elements for general angular momentum in terms of overlap and potential-energy integrals. It is shown here that a strategic application of angular-momentum theory, including the use of vector spherical harmonics, enables the reduction of all atomic kinetic-energy integrals to overlap and potential-energy matrix elements. The new formulas are validated by showing that they yield correct results for a large number of integrals published by other investigators.
Derivation of many-body potential among charged particles in the S-matrix method
NASA Astrophysics Data System (ADS)
Ohta, Tadayuki; Kimura, Toshiei
1992-06-01
A general method of deriving a classical potential from the S-matrix element of particle scattering in the theory of quantized fields is applied to electrodynamics to the post-post-Coulombian approximation. To obtain the many-body potential, a consistent prescription is implemented in subtracting the contributions of the repetition of lower-order potential from the S-matrix elements of the higher-order diagrams. The result shows that the four-body potential between charged particles has a characteristic feature at a large distance and the two-body potential is identical with that given in the reduced Hamiltonian of Wheeler-Feynman electrodynamics. The advantage of the S-matrix method over the canonical formalism is to give the potential directly, without complicated treatment of the interaction with higher derivatives by a method of constrained dynamics.
Determination of CKM Matrix Elements with Superallowed Fermi Decays^*.
NASA Astrophysics Data System (ADS)
Fujikawa, Brian
1996-10-01
The u-d element (V_ud) of the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix is a fundamental parameter of the Standard Model of Electroweak Interactions. Its most precise determination comes from nuclear physics experiments, in particular, from measurements of superallowed Fermi beta decays. Precise knowledge of V_ud will allow a variety of tests of the Standard Model, in addition to placing a number of important constraints on astrophysics and cosmology. These measurements, which require both precision nuclear physics experiments and state of the art theoretical nuclear physics calculations, have been made for a variety of nuclei ranging from ^14O to ^54Co. The u-d element obtained from these measurements are in statistical agreement and the average value obtained implies a non-unitary CKM matrix, which if correct, would require exotic extensions to the Standard Model. Unfortunately the theoretical calculations of the isospin breaking corrections, which are necessary to extract V_ud, are controversial. In order to resolve this controversy, much effort has recently been invested in measuring V_ud from the superallowed Fermi decay of ^10C, where the isospin breaking corrections are expected to be small. This is a very challenging experiment, since it requires the precision measurement of very small branching ratios in a high background environment. I will report on the current status of the determination of V_ud emphasizing the recent experimental effort to measure V_ud from the superallowed Fermi decay of ^10C. ^*Supported by the U.S. D.O.E. under Contracts No. W-31-109-ENG-38 and No. DE-AC03-76SF00098.
Fabrication of synthetic diffractive elements using advanced matrix laser lithography
NASA Astrophysics Data System (ADS)
Škereň, M.; Svoboda, J.; Květoň, M.; Fiala, P.
2013-02-01
In this paper we present a matrix laser writing device based on a demagnified projection of a micro-structure from a computer driven spatial light modulator. The device is capable of writing completely aperiodic micro-structures with resolution higher than 200 000 DPI. An optical system is combined with ultra high precision piezoelectric stages with an elementary step ~ 4 nm. The device operates in a normal environment, which significantly decreases the costs compared to competitive technologies. Simultaneously, large areas can be exposed up to 100 cm2. The capabilities of the constructed device will be demonstrated on particular elements fabricated for real applications. The optical document security is the first interesting field, where the synthetic image holograms are often combined with sophisticated aperiodic micro-structures. The proposed technology can easily write simple micro-gratings creating the color and kinetic visual effects, but also the diffractive cryptograms, waveguide couplers, and other structures recently used in the field of optical security. A general beam shaping elements and special photonic micro-structures are another important applications which will be discussed in this paper.
NASA Technical Reports Server (NTRS)
Newman, M. B.; Filstrup, A. W.
1973-01-01
Linear (8 node), parabolic (20 node), cubic (32 node) and mixed (some edges linear, some parabolic and some cubic) have been inserted into NASTRAN, level 15.1. First the dummy element feature was used to check out the stiffness matrix generation routines for the linear element in NASTRAN. Then, the necessary modules of NASTRAN were modified to include the new family of elements. The matrix assembly was changed so that the stiffness matrix of each isoparametric element is only generated once as the time to generate these higher order elements tends to be much longer than the other elements in NASTRAN. This paper presents some of the experiences and difficulties of inserting a new element or family of elements into NASTRAN.
Neutrinoless Double Beta Nuclear Matrix Elements Around Mass 80 in the Nuclear Shell Model
NASA Astrophysics Data System (ADS)
Yoshinaga, Naotaka; Higashiyama, Koji; Taguchi, Daisuke; Teruya, Eri
The observation of the neutrinoless double-beta decay can determine whether the neutrino is a Majorana particle or not. In its theoretical nuclear side it is particularly important to estimate three types of nuclear matrix elements, namely, Fermi (F), Gamow-Teller (GT), and tensor (T) types matrix elements. The shell model calculations and also the pair-truncated shell model calculations are carried out to check the model dependence on nuclear matrix elements. In this work the neutrinoless double-beta decay for mass A = 82 nuclei is studied. It is found that the matrix elements are quite sensitive to the ground state wavefunctions.
Determination of the weak magnetism matrix element in {sup 14}C beta decay
Zeuli, A.R.; Ahmad, I.; Coulter, K.P.; Greene, J.P.; Schiffer, J.P.; Freedman, S.J.; Fujikawa, B.K.; Mortara, J.L.
1993-10-01
Higher order beta decay matrix elements, such as weak magnetism, will introduce small departures (a shape factor) from the allowed beta decay electron energy spectrum. The value of the weak magnetism matrix element is predicted by the Conserved Vector Current (CVC) hypothesis and an experimental determination of the weak magnetism matrix element can be interpreted as a test of CVC. We have determined the weak magnetism matrix element from the {sup 14}C shape factor, which was measured using an apparatus incorporating a high resolution solid state detector and a super conducting solenoid. The results of our measurement will be presented.
Controlling excited-state contamination in nucleon matrix elements
Yoon, Boram; Gupta, Rajan; Bhattacharya, Tanmoy; Engelhardt, Michael; Green, Jeremy; Joo, Balint; Lin, Huey -Wen; Negele, John; Orginos, Kostas; Pochinsky, Andrew; Richards, David; Syritsyn, Sergey; Winter, Frank
2016-06-08
We present a detailed analysis of methods to reduce statistical errors and excited-state contamination in the calculation of matrix elements of quark bilinear operators in nucleon states. All the calculations were done on a 2+1-flavor ensemble with lattices of size 32^{3} × 64 generated using the rational hybrid Monte Carlo algorithm at a = 0.081 fm and with M_{π} = 312 MeV. The statistical precision of the data is improved using the all-mode-averaging method. We compare two methods for reducing excited-state contamination: a variational analysis and a 2-state fit to data at multiple values of the source-sink separation t_{sep}. We show that both methods can be tuned to significantly reduce excited-state contamination and discuss their relative advantages and cost effectiveness. As a result, a detailed analysis of the size of source smearing used in the calculation of quark propagators and the range of values of t_{sep} needed to demonstrate convergence of the isovector charges of the nucleon to the t_{sep} → ∞ estimates is presented.
Controlling excited-state contamination in nucleon matrix elements
Yoon, Boram; Gupta, Rajan; Bhattacharya, Tanmoy; ...
2016-06-08
We present a detailed analysis of methods to reduce statistical errors and excited-state contamination in the calculation of matrix elements of quark bilinear operators in nucleon states. All the calculations were done on a 2+1-flavor ensemble with lattices of size 323 × 64 generated using the rational hybrid Monte Carlo algorithm at a = 0.081 fm and with Mπ = 312 MeV. The statistical precision of the data is improved using the all-mode-averaging method. We compare two methods for reducing excited-state contamination: a variational analysis and a 2-state fit to data at multiple values of the source-sink separation tsep. Wemore » show that both methods can be tuned to significantly reduce excited-state contamination and discuss their relative advantages and cost effectiveness. As a result, a detailed analysis of the size of source smearing used in the calculation of quark propagators and the range of values of tsep needed to demonstrate convergence of the isovector charges of the nucleon to the tsep → ∞ estimates is presented.« less
Controlling excited-state contamination in nucleon matrix elements
Yoon, Boram; Gupta, Rajan; Bhattacharya, Tanmoy; Engelhardt, Michael; Green, Jeremy; Joó, Bálint; Lin, Huey-Wen; Negele, John; Orginos, Kostas; Pochinsky, Andrew; Richards, David; Syritsyn, Sergey; Winter, Frank
2016-06-01
We present a detailed analysis of methods to reduce statistical errors and excited-state contamination in the calculation of matrix elements of quark bilinear operators in nucleon states. All the calculations were done on a 2+1 flavor ensemble with lattices of size $32^3 \\times 64$ generated using the rational hybrid Monte Carlo algorithm at $a=0.081$~fm and with $M_\\pi=312$~MeV. The statistical precision of the data is improved using the all-mode-averaging method. We compare two methods for reducing excited-state contamination: a variational analysis and a two-state fit to data at multiple values of the source-sink separation $t_{\\rm sep}$. We show that both methods can be tuned to significantly reduce excited-state contamination and discuss their relative advantages and cost-effectiveness. A detailed analysis of the size of source smearing used in the calculation of quark propagators and the range of values of $t_{\\rm sep}$ needed to demonstrate convergence of the isovector charges of the nucleon to the $t_{\\rm sep} \\to \\infty $ estimates is presented.
A top quark mass measurement using a matrix element method
Linacre, Jacob Thomas
2009-01-01
A measurement of the mass of the top quark is presented, using top-antitop pair (t$\\bar{t}$) candidate events for the lepton+jets decay channel. The measurement makes use of Tevatron p$\\bar{p}$ collision data at centre-of-mass energy √s = 1.96 TeV, collected at the CDF detector. The top quark mass is measured by employing an unbinned maximum likelihood method where the event probability density functions are calculated using signal (t$\\bar{t}$) and background (W+jets) matrix elements, as well as a set of parameterised jet-to-parton mapping functions. The likelihood function is maximised with respect to the top quark mass, the fraction of signal events, and a correction to the jet energy scale (JES) of the calorimeter jets. The simultaneous measurement of the JES correction (Δ_{JES}) provides an in situ jet energy calibration based on the known mass of the hadronically decaying W boson. Using 578 lepton+jets candidate events corresponding to 3.2 fb ^{-1} of integrated luminosity, the top quark mass is measured to be m_{t} = 172.4± 1.4 (stat+Δ_{JES}) ±1.3 (syst) GeV=c^{2}, one of the most precise single measurements to date.
North African geology: exploration matrix for potential major hydrocarbon discoveries
Kanes, W.H.; O'Connor, T.E.
1985-02-01
Based on results and models presented previously, it is possible to consider an exploration matrix that examines the 5 basic exploration parameters: source, reservoir, timing, structure, and seal. This matrix indicates that even those basins that have had marginal exploration successes, including the Paleozoic megabasin and downfaulted Triassic grabens of Morocco, the Cyrenaican platform of Libya, and the Tunisia-Sicily shelf, have untested plays. The exploration matrix also suggests these high-risk areas could change significantly, if one of the 5 basic matrix parameters is upgraded or if adjustments in political or financial risk are made. The Sirte basin and the Gulf of Suez, 2 of the more intensely explored areas, also present attractive matrix prospects, particularly with deeper Nubian beds or with the very shallow Tertiary sections. The Ghadames basin of Libya and Tunisia shows some potential, but its evaluation responds strongly to stratigraphic and external nongeologic matrix variations based on degree of risk exposure to be assumed. Of greatest risk in the matrix are the very deep Moroccan Paleozoic clastic plays and the Jurassic of Sinai. However, recent discoveries may upgrade these untested frontier areas. Based on the matrix generated by the data presented at a North African Petroleum Geology symposium, significant hydrocarbon accumulations are yet to be found. The remaining questions are: where in the matrix does each individual company wish to place its exploration capital and how much should be the risk exposure.
Application of the Finite-Element Z-Matrix Method to e-H2 Collisions
NASA Technical Reports Server (NTRS)
Huo, Winifred M.; Brown, David; Langhoff, Stephen R. (Technical Monitor)
1997-01-01
The present study adapts the Z-matrix formulation using a mixed basis of finite elements and Gaussians. This is a energy-independent basis which allows flexible boundary conditions and is amenable to efficient algorithms for evaluating the necessary matrix elements with molecular targets.
Calculation of Moment Matrix Elements for Bilinear Quadrilaterals and Higher-Order Basis Functions
2016-01-06
B. M. Kolundzija and A. R. Djordjević, Electromagnetic Modeling of Composite Metallic and Dielectric Structures . Boston: Artech House, 2002...REPORT REPORT NO: NAWCADPAX/TR-2015/241 CALCULATION OF MOMENT MATRIX ELEMENTS FOR BILINEAR QUADRILATERALS AND HIGHER-ORDER BASIS...CALCULATION OF MOMENT MATRIX ELEMENTS FOR BILINEAR QUADRILATERALS AND HIGHER-ORDER BASIS FUNCTIONS by John S. Asvestas
Localization in band random matrix models with and without increasing diagonal elements.
Wang, Wen-ge
2002-06-01
It is shown that localization of eigenfunctions in the Wigner band random matrix model with increasing diagonal elements can be related to localization in a band random matrix model with random diagonal elements. The relation is obtained by making use of a result of a generalization of Brillouin-Wigner perturbation theory, which shows that reduced Hamiltonian matrices with relatively small dimensions can be introduced for nonperturbative parts of eigenfunctions, and by employing intermediate basis states, which can improve the method of the reduced Hamiltonian matrix. The latter model deviates from the standard band random matrix model mainly in two aspects: (i) the root mean square of diagonal elements is larger than that of off-diagonal elements within the band, and (ii) statistical distributions of the matrix elements are close to the Lévy distribution in their central parts, except in the high top regions.
Uncertainty evaluation for the matrix ``solidified state'' of fissionable elements
NASA Astrophysics Data System (ADS)
Iliescu, Elena; Iancso, Georgeta
2012-09-01
In case of the analysis of the radioactive liquid samples, no matter the relative physical analysis method used, two impediments act that belong to the behavior in time of the dispersion state of the liquid samples to be analyzed and of the standard used in the analysis. That is, one of them refers to the state of the sample to be analyzed when being sampled, which "alter" during the time elapsed from sampling up to the analysis of the sample. The other impediment is the natural change of the dispersion state of the standard radioactive solutions, due to the occurrence and evolution in time of the radiocolloidal and pseudo-radiocolloidal states. These radiocolloidal states are states of aggregation and they lead to the destruction of the homogeneity of the solutions. Taking into consideration the advantages offered by the relative physical methods of analysis as against the chemical or the radiochemical ones, different ways of eliminating these impediments have been tried. We eliminated these impediments processing the liquid reference materials (the solutions calibrated in radionuclides of interest), immediately after the preparation. This processing changes the liquid physical state of the reference materials in a "solidified state". Through this procedure the dispersion states of the samples, practically, can no longer be essentially modified in time and also ensure the uniform distribution of the radionuclides of interest in the elemental matrix of the samples "state solidified". The homogeneity of the distribution of the atoms of the radionuclides from the samples "solidified state" was checked up through the track micromapping technique of the alpha particles. Through this technique, in the chemically etched track detectors that were put in direct contact with the sample for a determined period of time, the alpha exposure time of the detectors, micromaps of alpha tracks were obtained. These micromaps are retorts through tracks of the distributions atoms of
Finite element analysis of metal matrix composite blade
NASA Astrophysics Data System (ADS)
Isai Thamizh, R.; Velmurugan, R.; Jayagandhan, R.
2016-10-01
In this work, compressor rotor blade of a gas turbine engine has been analyzed for stress, maximum displacement and natural frequency using ANSYS software for determining its failure strength by simulating the actual service conditions. Static stress analysis and modal analysis have been carried out using Ti-6Al-4V alloy, which is currently used in compressor blade. The results are compared with those obtained using Ti matrix composites reinforced with SiC. The advantages of using metal matrix composites in the gas turbine compressor blades are investigated. From the analyses carried out, it seems that composite rotor blades have lesser mass, lesser tip displacement and lower maximum stress values.
NASA Astrophysics Data System (ADS)
Lü, Ling; Liu, Shuo; Li, Gang; Zhao, Guannan; Gu, Jiajia; Tian, Jing; Wang, Zhouyang
2016-11-01
In this paper, we research the outer synchronization among discrete networks with different topologies. Based on Lyapunov theorem, a novel synchronization technique is designed. Further, the control inputs of the networks and the adaptive laws of configuration matrix element are obtained. In the end, a numerical example is given to illustrate the effectiveness of the synchronization technique. It is found that the designed control input of the networks ensures the convergence of the errors among the networks to zero. And the designed adaptive law of configuration matrix element can replace effectively configuration matrix element in networks.
EH3 matrix mineralogy with major and trace element composition compared to chondrules
NASA Astrophysics Data System (ADS)
Lehner, S. W.; McDonough, W. F.; NéMeth, P.
2014-12-01
We investigated the matrix mineralogy in primitive EH3 chondrites Sahara 97072, ALH 84170, and LAR 06252 with transmission electron microscopy; measured the trace and major element compositions of Sahara 97072 matrix and ferromagnesian chondrules with laser-ablation, inductively coupled, plasma mass spectrometry (LA-ICPMS); and analyzed the bulk composition of Sahara 97072 with LA-ICPMS, solution ICPMS, and inductively coupled plasma atomic emission spectroscopy. The fine-grained matrix of EH3 chondrites is unlike that in other chondrite groups, consisting primarily of enstatite, cristobalite, troilite, and kamacite with a notable absence of olivine. Matrix and pyroxene-rich chondrule compositions differ from one another and are distinct from the bulk meteorite. Refractory lithophile elements are enriched by a factor of 1.5-3 in chondrules relative to matrix, whereas the matrix is enriched in moderately volatile elements. The compositional relation between the chondrules and matrix is reminiscent of the difference between EH3 pyroxene-rich chondrules and EH3 Si-rich, highly sulfidized chondrules. Similar refractory element ratios between the matrix and the pyroxene-rich chondrules suggest the fine-grained material primarily consists of the shattered, sulfidized remains of the formerly pyroxene-rich chondrules with the minor addition of metal clasts. The matrix, chondrule, and metal-sulfide nodule compositions are probably complementary, suggesting all the components of the EH3 chondrites came from the same nebular reservoir.
NASA Astrophysics Data System (ADS)
Komninos, Yannis; Mercouris, Theodoros; Nicolaides, Cleanthes A.
2017-01-01
The present study examines the mathematical properties of the free-free ( f - f) matrix elements of the full electric field operator, O E (κ, r̅), of the multipolar Hamiltonian. κ is the photon wavenumber. Special methods are developed and applied for their computation, for the general case where the scattering wavefunctions are calculated numerically in the potential of the term-dependent ( N - 1) electron core, and are energy-normalized. It is found that, on the energy axis, the f - f matrix elements of O E (κ, r̅) have singularities of first order, i.e., as ɛ' → ɛ, they behave as ( ɛ - ɛ')-1. The numerical applications are for f - f transitions in hydrogen and neon, obeying electric dipole and quadrupole selection rules. In the limit κ = 0, O E (κ, r̅) reduces to the length form of the electric dipole approximation (EDA). It is found that the results for the EDA agree with those of O E (κ, r̅), with the exception of a wave-number region k' = k ± κ about the point k' = k.
Calculation of Radiative Corrections to E1 matrix elements in the Neutral Alkalis
Sapirstein, J; Cheng, K T
2004-09-28
Radiative corrections to E1 matrix elements for ns-np transitions in the alkali metal atoms lithium through francium are evaluated. They are found to be small for the lighter alkalis but significantly larger for the heavier alkalis, and in the case of cesium much larger than the experimental accuracy. The relation of the matrix element calculation to a recent decay rate calculation for hydrogenic ions is discussed, and application of the method to parity nonconservation in cesium is described.
Neutrinoless double beta nuclear matrix elements around mass 80 in the nuclear shell-model
NASA Astrophysics Data System (ADS)
Yoshinaga, N.; Higashiyama, K.; Taguchi, D.; Teruya, E.
2015-05-01
The observation of the neutrinoless double-beta decay can determine whether the neutrino is a Majorana particle or not. For theoretical nuclear physics it is particularly important to estimate three types of matrix elements, namely Fermi (F), Gamow-Teller (GT), and tensor (T) matrix elements. In this paper, we carry out shell-model calculations and also pair-truncated shell-model calculations to check the model dependence in the case of mass A=82 nuclei.
Matrix elements and duality for type 2 unitary representations of the Lie superalgebra gl(m|n)
Werry, Jason L.; Gould, Mark D.; Isaac, Phillip S.
2015-12-15
The characteristic identity formalism discussed in our recent articles is further utilized to derive matrix elements of type 2 unitary irreducible gl(m|n) modules. In particular, we give matrix element formulae for all gl(m|n) generators, including the non-elementary generators, together with their phases on finite dimensional type 2 unitary irreducible representations which include the contravariant tensor representations and an additional class of essentially typical representations. Remarkably, we find that the type 2 unitary matrix element equations coincide with the type 1 unitary matrix element equations for non-vanishing matrix elements up to a phase.
Symbolic algorithms for the computation of Moshinsky brackets and nuclear matrix elements
NASA Astrophysics Data System (ADS)
Ursescu, D.; Tomaselli, M.; Kuehl, T.; Fritzsche, S.
2005-12-01
. Method of solution:Moshinsky's transformation brackets as well as two-nucleon matrix elements are provided within the framework of MAPLE. The transformation brackets are evaluated recursively for a given number of shells and utilized for the computation of the two-particle matrix elements for different coupling schemes and interactions. Moreover, a simple notation has been introduced to handle the two-particle nuclear states in ll-, LSJ-, and jj-coupling, both in the center-of-well and the relative and center-of-mass coordinates. Restrictions onto the complexity of the problem:The program supports in principle an arbitrary number of shell states with the only limitation given by the computer resources themselves. Typically, the time requirements for the recursive computation of the Moshinsky brackets and matrix elements increase rapidly with the number of the allowed shell states but can be reduced significantly by the pre-calculation of the transformation brackets. Unusual features of the program:Moshinsky brackets are computed and provided in either numeric, algebraic or some symbolic form. In addition, the two-particle matrix elements are calculated for a scalar potential, spin-orbit coupling and tensorial forces, both in floating-point and algebraic notation. All two-particle matrix elements are expressed in terms of the Talmi integrals but can be evaluated also explicitly for several predefined types of the interaction. To simplify the handling of the program, a short but very powerful notation has been introduced which help the user to deal with the two-particle states in various coupling notations. The main commands of the current version of the program are described in detail in Appendix B. Typical running time:The computation of all Moshinsky brackets in floating-point notation, up to ρ=6, takes about 5 s at a 2.26 GHz Intel Pentium IIII processor with 512 MB; in algebraic form, the same computations take about 13 s. Similarly, the computation of these brackets
NASA Astrophysics Data System (ADS)
Todoroki, Akira; Omagari, Kazuomi
Carbon Fiber Reinforced Plastic (CFRP) laminates are adopted for fuel tank structures of next generation space rockets or automobiles. Matrix cracks may cause fuel leak or trigger fatigue damage. A monitoring system of the matrix crack density is required. The authors have developed an electrical resistance change method for the monitoring of delamination cracks in CFRP laminates. Reinforcement fibers are used as a self-sensing system. In the present study, the electric potential method is adopted for matrix crack density monitoring. Finite element analysis (FEA) was performed to investigate the possibility of monitoring matrix crack density using multiple electrodes mounted on a single surface of a specimen. The FEA reveals the matrix crack density increases electrical resistance for a target segment between electrodes. Experimental confirmation was also performed using cross-ply laminates. Eight electrodes were mounted on a single surface of a specimen using silver paste after polishing of the specimen surface with sandpaper. The two outermost electrodes applied electrical current, and the inner electrodes measured electric voltage changes. The slope of electrical resistance during reloading is revealed to be an appropriate index for the detection of matrix crack density.
0{nu}{beta}{beta}-decay nuclear matrix elements with self-consistent short-range correlations
Simkovic, Fedor; Faessler, Amand; Muether, Herbert; Rodin, Vadim; Stauf, Markus
2009-05-15
A self-consistent calculation of nuclear matrix elements of the neutrinoless double-beta decays (0{nu}{beta}{beta}) of {sup 76}Ge, {sup 82}Se, {sup 96}Zr, {sup 100}Mo, {sup 116}Cd, {sup 128}Te, {sup 130}Te, and {sup 136}Xe is presented in the framework of the renormalized quasiparticle random phase approximation (RQRPA) and the standard QRPA. The pairing and residual interactions as well as the two-nucleon short-range correlations are for the first time derived from the same modern realistic nucleon-nucleon potentials, namely, from the charge-dependent Bonn potential (CD-Bonn) and the Argonne V18 potential. In a comparison with the traditional approach of using the Miller-Spencer Jastrow correlations, matrix elements for the 0{nu}{beta}{beta} decay are obtained that are larger in magnitude. We analyze the differences among various two-nucleon correlations including those of the unitary correlation operator method (UCOM) and quantify the uncertainties in the calculated 0{nu}{beta}{beta}-decay matrix elements.
Matrix elements of Δ B =0 operators in heavy hadron chiral perturbation theory
NASA Astrophysics Data System (ADS)
Lee, Jong-Wan
2015-05-01
We study the light-quark mass and spatial volume dependence of the matrix elements of Δ B =0 four-quark operators relevant for the determination of Vu b and the lifetime ratios of single-b hadrons. To this end, one-loop diagrams are computed in the framework of heavy hadron chiral perturbation theory with partially quenched formalism for three light-quark flavors in the isospin limit; flavor-connected and -disconnected diagrams are carefully analyzed. These calculations include the leading light-quark flavor and heavy-quark spin symmetry breaking effects in the heavy hadron spectrum. Our results can be used in the chiral extrapolation of lattice calculations of the matrix elements to the physical light-quark masses and to infinite volume. To provide insight on such chiral extrapolation, we evaluate the one-loop contributions to the matrix elements containing external Bd, Bs mesons and Λb baryon in the QCD limit, where sea and valence quark masses become equal. In particular, we find that the matrix elements of the λ3 flavor-octet operators with an external Bd meson receive the contributions solely from connected diagrams in which current lattice techniques are capable of precise determination of the matrix elements. Finite volume effects are at most a few percent for typical lattice sizes and pion masses.
Insights into Nuclear Triaxiality from Interference Effects in E2 Matrix Elements
NASA Astrophysics Data System (ADS)
Allmond, J. M.; Wood, J. L.; Kulp, W. D.
2007-10-01
Recently, we have introduced [1] a triaxial rotor model with independent inertia and E2 tensors. The E2 matrix elements [2] of the osmium isotopes (186, 188, 190, and 192) are studied in the framework of this model (59 of 84 E2 matrix elements deviate by 30% or less). It is shown that interference effects in the inertia tensor (K-mixing) and the E2 tensor can lead to significant reductions in the diagonal E2 matrix elements. In some instances, the diagonal E2 matrix elements may decrease with increasing spin. Additionally, a sum rule for diagonal E2 matrix elements is shown and used to explore missing strength from K-admixtures. [1] J.L. Wood, A-M. Oros-Peusquens, R. Zaballa, J.M. Allmond, and W.D. Kulp, Phys. Rev. C 70, 024308 (2004). [2] C.Y. Wu, D. Cline, T. Czosnyka, A. Backlin, C. Baktash, R.M. Diamond, G.D. Dracoulis, L. Hasselgren, H. Kluge, et al., Nucl. Phys. A607, 178 (1996).
Mesh refinement in finite element analysis by minimization of the stiffness matrix trace
NASA Technical Reports Server (NTRS)
Kittur, Madan G.; Huston, Ronald L.
1989-01-01
Most finite element packages provide means to generate meshes automatically. However, the user is usually confronted with the problem of not knowing whether the mesh generated is appropriate for the problem at hand. Since the accuracy of the finite element results is mesh dependent, mesh selection forms a very important step in the analysis. Indeed, in accurate analyses, meshes need to be refined or rezoned until the solution converges to a value so that the error is below a predetermined tolerance. A-posteriori methods use error indicators, developed by using the theory of interpolation and approximation theory, for mesh refinements. Some use other criterions, such as strain energy density variation and stress contours for example, to obtain near optimal meshes. Although these methods are adaptive, they are expensive. Alternatively, a priori methods, until now available, use geometrical parameters, for example, element aspect ratio. Therefore, they are not adaptive by nature. An adaptive a-priori method is developed. The criterion is that the minimization of the trace of the stiffness matrix with respect to the nodal coordinates, leads to a minimization of the potential energy, and as a consequence provide a good starting mesh. In a few examples the method is shown to provide the optimal mesh. The method is also shown to be relatively simple and amenable to development of computer algorithms. When the procedure is used in conjunction with a-posteriori methods of grid refinement, it is shown that fewer refinement iterations and fewer degrees of freedom are required for convergence as opposed to when the procedure is not used. The mesh obtained is shown to have uniform distribution of stiffness among the nodes and elements which, as a consequence, leads to uniform error distribution. Thus the mesh obtained meets the optimality criterion of uniform error distribution.
Quenched domain wall QCD with DBW2 gauge action toward nucleon decay matrix element calculation
NASA Astrophysics Data System (ADS)
Aoki, Yasumichi
2001-10-01
The domain wall fermion action is a promising way to control chiral symmetry in lattice gauge theory. By the good chiral symmetry of this approach even at finite lattice spacing, one is able to extract hadronic matrix elements, like kaon weak matrix elements, for which the symmetry is extremely important. Ordinary fermions with poor chiral symmetry make calculation difficult because of the large mixing of operators with different chiral structure. Even though the domain wall fermion action with the simple Wilson gauge action has a good chiral symmetry, one can further improve the symmetry by using a different gauge action. We take a non-perturbatively improved action, the DBW2 action of the QCD Taro group. Hadron masses are systematically examined for a range of parameters. Application to nucleon decay matrix element is also discussed.
B(s) 0-mixing matrix elements from lattice QCD for the Standard Model and beyond
NASA Astrophysics Data System (ADS)
Bazavov, A.; Bernard, C.; Bouchard, C. M.; Chang, C. C.; DeTar, C.; Du, Daping; El-Khadra, A. X.; Freeland, E. D.; Gámiz, E.; Gottlieb, Steven; Heller, U. M.; Kronfeld, A. S.; Laiho, J.; Mackenzie, P. B.; Neil, E. T.; Simone, J.; Sugar, R.; Toussaint, D.; Van de Water, R. S.; Zhou, Ran; Fermilab Lattice; MILC Collaborations
2016-06-01
We calculate—for the first time in three-flavor lattice QCD—the hadronic matrix elements of all five local operators that contribute to neutral B0- and Bs-meson mixing in and beyond the Standard Model. We present a complete error budget for each matrix element and also provide the full set of correlations among the matrix elements. We also present the corresponding bag parameters and their correlations, as well as specific combinations of the mixing matrix elements that enter the expression for the neutral B -meson width difference. We obtain the most precise determination to date of the SU(3)-breaking ratio ξ =1.206 (18 )(6 ), where the second error stems from the omission of charm-sea quarks, while the first encompasses all other uncertainties. The threefold reduction in total uncertainty, relative to the 2013 Flavor Lattice Averaging Group results, tightens the constraint from B mixing on the Cabibbo-Kobayashi-Maskawa (CKM) unitarity triangle. Our calculation employs gauge-field ensembles generated by the MILC Collaboration with four lattice spacings and pion masses close to the physical value. We use the asqtad-improved staggered action for the light-valence quarks and the Fermilab method for the bottom quark. We use heavy-light meson chiral perturbation theory modified to include lattice-spacing effects to extrapolate the five matrix elements to the physical point. We combine our results with experimental measurements of the neutral B -meson oscillation frequencies to determine the CKM matrix elements |Vt d|=8.00 (34 )(8 )×10-3, |Vt s|=39.0 (1.2 )(0.4 )×10-3, and |Vt d/Vt s|=0.2052 (31 )(10 ), which differ from CKM-unitarity expectations by about 2 σ . These results and others from flavor-changing-neutral currents point towards an emerging tension between weak processes that are mediated at the loop and tree levels.
Calculation of radiative corrections to E1 matrix elements in the neutral alkali metals
Sapirstein, J.; Cheng, K.T.
2005-02-01
Radiative corrections to E1 matrix elements for ns-np transitions in the alkali-metal atoms lithium through francium are evaluated. They are found to be small for the lighter alkali metals but significantly larger for the heavier alkali metals, and in the case of cesium much larger than the experimental accuracy. The relation of the matrix element calculation to a recent decay rate calculation for hydrogenic ions is discussed, and application of the method to parity nonconservation in cesium is described.
Analytic matrix elements for the two-electron atomic basis with logarithmic terms
Liverts, Evgeny Z.; Barnea, Nir
2014-08-01
The two-electron problem for the helium-like atoms in S-state is considered. The basis containing the integer powers of ln r, where r is a radial variable of the Fock expansion, is studied. In this basis, the analytic expressions for the matrix elements of the corresponding Hamiltonian are presented. These expressions include only elementary and special functions, what enables very fast and accurate computation of the matrix elements. The decisive contribution of the correct logarithmic terms to the behavior of the two-electron wave function in the vicinity of the triple-coalescence point is reaffirmed.
Double β-decay nuclear matrix elements for the A=48 and A=58 systems
NASA Astrophysics Data System (ADS)
Skouras, L. D.; Vergados, J. D.
1983-11-01
The nuclear matrix elements entering the double β decays of the 48Ca-48Ti and 58Ni-58Fe systems have been calculated using a realistic two nucleon interaction and realistic shell model spaces. Effective transition operators corresponding to a variety of gauge theory models have been considered. The stability of such matrix elements against variations of the nuclear parameters is examined. Appropriate lepton violating parameters are extracted from the A=48 data and predictions are made for the lifetimes of the positron decays of the A=58 system. RADIOACTIVITY Double β decay. Gauge theories. Lepton nonconservation. Neutrino mass. Shell model calculations.
NASA Astrophysics Data System (ADS)
Cave, Robert J.; Newton, Marshall D.
1996-01-01
A new method for the calculation of the electronic coupling matrix element for electron transfer processes is introduced and results for several systems are presented. The method can be applied to ground and excited state systems and can be used in cases where several states interact strongly. Within the set of states chosen it is a non-perturbative treatment, and can be implemented using quantities obtained solely in terms of the adiabatic states. Several applications based on quantum chemical calculations are briefly presented. Finally, since quantities for adiabatic states are the only input to the method, it can also be used with purely experimental data to estimate electron transfer matrix elements.
Semiclassical matrix elements for a chaotic propagator in the scar function basis
NASA Astrophysics Data System (ADS)
Rivas, Alejandro M. F.
2013-04-01
A semiclassical approximation for the matrix elements of a quantum chaotic propagator in the scar function basis has been derived. The obtained expression is solely expressed in terms of canonical invariant objects. For our purpose, we have used the recently developed, semiclassical matrix elements of the propagator in coherent states, together with the linearization of the flux in the neighborhood of a classically unstable periodic orbit of chaotic two-dimensional systems. The expression derived here is successfully verified to be exact for a (linear) cat map, after the theory is adapted to a discrete phase space appropriate to a quantized torus.
NASA Astrophysics Data System (ADS)
Fatchurrohman, N.; Marini, C. D.; Suraya, S.; Iqbal, AKM Asif
2016-02-01
The increasing demand of fuel efficiency and light weight components in automobile sectors have led to the development of advanced material parts with improved performance. A specific class of MMCs which has gained a lot of attention due to its potential is aluminium metal matrix composites (Al-MMCs). Product performance investigation of Al- MMCs is presented in this article, where an Al-MMCs brake disc is analyzed using finite element analysis. The objective is to identify the potentiality of replacing the conventional iron brake disc with Al-MMCs brake disc. The simulation results suggested that the MMCs brake disc provided better thermal and mechanical performance as compared to the conventional cast iron brake disc. Although, the Al-MMCs brake disc dissipated higher maximum temperature compared to cast iron brake disc's maximum temperature. The Al-MMCs brake disc showed a well distributed temperature than the cast iron brake disc. The high temperature developed at the ring of the disc and heat was dissipated in circumferential direction. Moreover, better thermal dissipation and conduction at brake disc rotor surface played a major influence on the stress. As a comparison, the maximum stress and strain of Al-MMCs brake disc was lower than that induced on the cast iron brake disc.
NASA Astrophysics Data System (ADS)
Kumar, Deepak; Roy, Rene; Kweon, Jin-Hwe; Choi, Jin-ho
2016-06-01
Sub-laminate damage in the form of matrix cracking and delamination was simulated by using interface cohesive elements in the finite element (FE) software ABAQUS. Interface cohesive elements were inserted parallel to the fiber orientation in the transverse ply with equal spacing (matrix cracking) and between the interfaces (delamination). Matrix cracking initiation in the cohesive elements was based on stress traction separation laws and propagated under mixed-mode loading. We expanded the work of Shi et al. (Appl. Compos. Mater. 21, 57-70 2014) to include delamination and simulated additional [45/-45/0/90]s and [02/90n]s { n = 1,2,3} CFRP laminates and a [0/903]s GFRP laminate. Delamination damage was quantified numerically in terms of damage dissipative energy. We observed that transverse matrix cracks can propagate to the ply interface and initiate delamination. We also observed for [0/90n/0] laminates that as the number of 90° ply increases past n = 2, the crack density decreases. The predicted crack density evolution compared well with experimental results and the equivalent constraint model (ECM) theory. Empirical relationships were established between crack density and applied stress by linear curve fitting. The reduction of laminate elastic modulus due to cracking was also computed numerically and it is in accordance with reported experimental measurements.
Matrix elements and diquark correlations in quenched QCD with overlap fermions.
NASA Astrophysics Data System (ADS)
Rebbi, Claudio
2006-12-01
We present results for BK and selected matrix elements for beyond the standard model interactions obtained in quenched QCD with overlap fermions. We also illustrate results on baryon wave- functions and diquark correlations within baryons in the Coulomb and Landau gauge.
Nuclear matrix element of neutrinoless double-β decay: Relativity and short-range correlations
NASA Astrophysics Data System (ADS)
Song, L. S.; Yao, J. M.; Ring, P.; Meng, J.
2017-02-01
Background:The discovery of neutrinoless double-β (0 ν β β ) decay would demonstrate the nature of neutrinos, have profound implications for our understanding of matter-antimatter mystery, and solve the mass hierarchy problem of neutrinos. The calculations for the nuclear matrix elements M0 ν of 0 ν β β decay are crucial for the interpretation of this process. Purpose: We study the effects of relativity and nucleon-nucleon short-range correlations on the nuclear matrix elements M0 ν by assuming the mechanism of exchanging light or heavy neutrinos for the 0 ν β β decay. Methods:The nuclear matrix elements M0 ν are calculated within the framework of covariant density functional theory, where the beyond-mean-field correlations are included in the nuclear wave functions by configuration mixing of both angular-momentum and particle-number projected quadrupole deformed mean-field states. Results: The nuclear matrix elements M0 ν are obtained for ten 0 ν β β -decay candidate nuclei. The impact of relativity is illustrated by adopting relativistic or nonrelativistic decay operators. The effects of short-range correlations are evaluated. Conclusions: The effects of relativity and short-range correlations play an important role in the mechanism of exchanging heavy neutrinos though the influences are marginal for light neutrinos. Combining the nuclear matrix elements M0 ν with the observed lower limits on the 0 ν β β -decay half-lives, the predicted strongest limits on the effective masses are |
Relativistic description of nuclear matrix elements in neutrinoless double-β decay
NASA Astrophysics Data System (ADS)
Song, L. S.; Yao, J. M.; Ring, P.; Meng, J.
2014-11-01
Background: Neutrinoless double-β (0 ν β β ) decay is related to many fundamental concepts in nuclear and particle physics beyond the standard model. Currently there are many experiments searching for this weak process. An accurate knowledge of the nuclear matrix element for the 0 ν β β decay is essential for determining the effective neutrino mass once this process is eventually measured. Purpose: We report the first full relativistic description of the 0 ν β β decay matrix element based on a state-of-the-art nuclear structure model. Methods: We adopt the full relativistic transition operators which are derived with the charge-changing nucleonic currents composed of the vector coupling, axial-vector coupling, pseudoscalar coupling, and weak-magnetism coupling terms. The wave functions for the initial and final nuclei are determined by the multireference covariant density functional theory (MR-CDFT) based on the point-coupling functional PC-PK1. Correlations beyond the mean field are introduced by configuration mixing of both angular momentum and particle number projected quadrupole deformed mean-field wave functions. Results: The low-energy spectra and electric quadrupole transitions in 150Nd and its daughter nucleus 150Sm are well reproduced by the MR-CDFT calculations. The 0 ν β β decay matrix elements for both the 01+→01+ and 01+→02+ decays of 150Nd are evaluated. The effects of particle number projection, static and dynamic deformations, and the full relativistic structure of the transition operators on the matrix elements are studied in detail. Conclusions: The resulting 0 ν β β decay matrix element for the 01+→01+ transition is 5.60 , which gives the most optimistic prediction for the next generation of experiments searching for the 0 ν β β decay in 150Nd.
Matrix-Assisted Plasma Atomization Emission Spectrometry for Surface Sampling Elemental Analysis
Yuan, Xin; Zhan, Xuefang; Li, Xuemei; Zhao, Zhongjun; Duan, Yixiang
2016-01-01
An innovative technology has been developed involving a simple and sensitive optical spectrometric method termed matrix-assisted plasma atomization emission spectrometry (MAPAES) for surface sampling elemental analysis using a piece of filter paper (FP) for sample introduction. MAPAES was carried out by direct interaction of the plasma tail plume with the matrix surface. The FP absorbs energy from the plasma source and releases combustion heating to the analytes originally present on its surface, thus to promote the atomization and excitation process. The matrix-assisted plasma atomization excitation phenomenon was observed for multiple elements. The FP matrix served as the partial energy producer and also the sample substrate to adsorb sample solution. Qualitative and quantitative determinations of metal ions were achieved by atomic emission measurements for elements Ba, Cu, Eu, In, Mn, Ni, Rh and Y. The detection limits were down to pg level with linear correlation coefficients better than 0.99. The proposed MAPAES provides a new way for atomic spectrometry which offers advantages of fast analysis speed, little sample consumption, less sample pretreatment, small size, and cost-effective. PMID:26762972
NASA Astrophysics Data System (ADS)
Reby Roy, K. E.; Mohammed, Jesna; Abhiroop, V. M.; Thekkethil, S. R.
2017-02-01
Cryogenic fluids have many applications in space, medicine, preservation etc. The chill-down of cryogenic fluid transfer line is a complicated phenomenon occurring in most of the cryogenic systems. The cryogenic fluid transfer line, which is initially at room temperature, has to be cooled to the temperature of the cryogen as fast as possible. When the cryogenic fluid at liquid state passes along the line, transient heat transfer between the cryogen and the transfer line causes voracious evaporation of the liquid. This paper makes a contribution to the two-phase flow along a rectangular flow passage consisting of an array of elliptically shaped matrix elements. A simplified 2D model is considered and the problem is solved using ANSYS FLUENT. The present analysis aims to study the influence of the slenderness ratio of matrix elements on the heat transfer rate and chill down time. For a comparative study, matrix elements of slenderness ratios 5 and 10 are considered. Liquid nitrogen at 74K flows through the matrix. The material of the transfer line is assumed to be aluminium which is initially at room temperature. The influence of Reynolds numbers from 800 to 3000 on chill-down is also investigated.
Potential of Organic Matrix Composites for Liquid Oxygen Tank
NASA Technical Reports Server (NTRS)
Davis, Samuel E.; Herald, Stephen D.; Stolzfus, Joel M.; Engel, Carl D.; Bohlen, James W.; Palm, Tod; Robinson, Michael J.
2005-01-01
Composite materials are being considered for the tankage of cryogenic propellants in access to space because of potentially lower structural weights. A major hurdle for composites is an inherent concern about the safety of using flammable structural materials in contact with liquid and gaseous oxygen. A hazards analysis approach addresses a series of specific concerns that must be addressed based upon test data. Under the 2nd Generation Reusable Launch Vehicle contracts, testing was begun for a variety of organic matrix composite materials both to aid in the selection of materials and to provide needed test data to support hazards analyses. The work has continued at NASA MSFC and the NASA WSTF to provide information on the potential for using composite materials in oxygen systems. Appropriate methods for oxygen compatibility testing of structural materials and data for a range of composite materials from impact, friction, flammability and electrostatic discharge testing are presented. Remaining concerns and conclusions about composite tank structures, and recommendations for additional testing are discussed. Requirements for system specific hazards analysis are identified.
$B^0_{(s)}$-mixing matrix elements from lattice QCD for the Standard Model and beyond
Bazavov, A.; Bernard, C.; Bouchard, C. M.; Chang, C. C.; DeTar, C.; Du, Daping; El-Khadra, A. X.; Freeland, E. D.; Gamiz, E.; Gottlieb, Steven; Heller, U. M.; Kronfeld, A. S.; Laiho, J.; Mackenzie, P. B.; Neil, E. T.; Simone, J.; Sugar, R.; Toussaint, D.; Van de Water, R. S.; Zhou, Ran
2016-06-28
We calculate—for the first time in three-flavor lattice QCD—the hadronic matrix elements of all five local operators that contribute to neutral B^{0}- and B_{s}-meson mixing in and beyond the Standard Model. We present a complete error budget for each matrix element and also provide the full set of correlations among the matrix elements. We also present the corresponding bag parameters and their correlations, as well as specific combinations of the mixing matrix elements that enter the expression for the neutral B-meson width difference. We obtain the most precise determination to date of the SU(3)-breaking ratio ξ=1.206(18)(6), where the second error stems from the omission of charm-sea quarks, while the first encompasses all other uncertainties. The threefold reduction in total uncertainty, relative to the 2013 Flavor Lattice Averaging Group results, tightens the constraint from B mixing on the Cabibbo-Kobayashi-Maskawa (CKM) unitarity triangle. Our calculation employs gauge-field ensembles generated by the MILC Collaboration with four lattice spacings and pion masses close to the physical value. We use the asqtad-improved staggered action for the light-valence quarks and the Fermilab method for the bottom quark. We use heavy-light meson chiral perturbation theory modified to include lattice-spacing effects to extrapolate the five matrix elements to the physical point. We combine our results with experimental measurements of the neutral B-meson oscillation frequencies to determine the CKM matrix elements |V_{td}| = 8.00(34)(8)×10^{-3}, |V_{ts}| = 39.0(1.2)(0.4)×10^{-3}, and |V_{td}/V_{ts}| = 0.2052(31)(10), which differ from CKM-unitarity expectations by about 2σ. In addition, these results and others from flavor-changing-neutral currents point towards an emerging tension between weak processes that are mediated at the loop and tree levels.
$$B^0_{(s)}$$-mixing matrix elements from lattice QCD for the Standard Model and beyond
Bazavov, A.; Bernard, C.; Bouchard, C. M.; ...
2016-06-28
We calculate—for the first time in three-flavor lattice QCD—the hadronic matrix elements of all five local operators that contribute to neutral B0- and Bs-meson mixing in and beyond the Standard Model. We present a complete error budget for each matrix element and also provide the full set of correlations among the matrix elements. We also present the corresponding bag parameters and their correlations, as well as specific combinations of the mixing matrix elements that enter the expression for the neutral B-meson width difference. We obtain the most precise determination to date of the SU(3)-breaking ratio ξ=1.206(18)(6), where the second errormore » stems from the omission of charm-sea quarks, while the first encompasses all other uncertainties. The threefold reduction in total uncertainty, relative to the 2013 Flavor Lattice Averaging Group results, tightens the constraint from B mixing on the Cabibbo-Kobayashi-Maskawa (CKM) unitarity triangle. Our calculation employs gauge-field ensembles generated by the MILC Collaboration with four lattice spacings and pion masses close to the physical value. We use the asqtad-improved staggered action for the light-valence quarks and the Fermilab method for the bottom quark. We use heavy-light meson chiral perturbation theory modified to include lattice-spacing effects to extrapolate the five matrix elements to the physical point. We combine our results with experimental measurements of the neutral B-meson oscillation frequencies to determine the CKM matrix elements |Vtd| = 8.00(34)(8)×10-3, |Vts| = 39.0(1.2)(0.4)×10-3, and |Vtd/Vts| = 0.2052(31)(10), which differ from CKM-unitarity expectations by about 2σ. In addition, these results and others from flavor-changing-neutral currents point towards an emerging tension between weak processes that are mediated at the loop and tree levels.« less
NASA Astrophysics Data System (ADS)
Möller, Thomas
2016-12-01
General expressions for the matrix elements of the tight-binding operator are presented using the Racah-Wigner algebra, where the wave functions are expressed as coupled multiplet wave functions within a given angular momentum coupling scheme. The knowledge of all possible Slater determinants is not necessary and the matrix elements can be written as compact expressions computable with arbitrary accuracy.
A novel FPGA-programmable switch matrix interconnection element in quantum-dot cellular automata
NASA Astrophysics Data System (ADS)
Hashemi, Sara; Rahimi Azghadi, Mostafa; Zakerolhosseini, Ali; Navi, Keivan
2015-04-01
The Quantum-dot cellular automata (QCA) is a novel nanotechnology, promising extra low-power, extremely dense and very high-speed structure for the construction of logical circuits at a nanoscale. In this paper, initially previous works on QCA-based FPGA's routing elements are investigated, and then an efficient, symmetric and reliable QCA programmable switch matrix (PSM) interconnection element is introduced. This element has a simple structure and offers a complete routing capability. It is implemented using a bottom-up design approach that starts from a dense and high-speed 2:1 multiplexer and utilise it to build the target PSM interconnection element. In this study, simulations of the proposed circuits are carried out using QCAdesigner, a layout and simulation tool for QCA circuits. The results demonstrate high efficiency of the proposed designs in QCA-based FPGA routing.
Nuclear matrix elements of the double beta decay for mass around 80
NASA Astrophysics Data System (ADS)
Yoshinaga, Naotaka; Higashiyama, Koji; Teruya, Eri
2014-09-01
In nature there are 30 kinds of nuclei which are expected to have double beta decays. Among them ten nuclei are actually observed for the neutrino double beta decays. Still no observation is made for the neutrinoless double beta decays (0 νββ) . The 0 νββ decay is expected to occur only when neutrinos have masses and they are Majorana particles. In that respect observation of 0 νββ is to determine whether neutrinos are Majorana particles or not. In theoretical side in order to estimate the half life of 0 νββ determination of the nuclear matrix elements are essential. They were calculated in many theoretical frameworks, but the results are not consistent in various models. In this study we carry out shell model calculations for 82Se and 82Kr nuclei. After obtaining the wavefunctions, we calculate the nuclear matrix elements. For comparison we make pair truncated shell model calculations.
Short-distance matrix elements for $D$-meson mixing for 2+1 lattice QCD
Chang, Chia Cheng
2015-01-01
We study the short-distance hadronic matrix elements for D-meson mixing with partially quenched N_{f} = 2+1 lattice QCD. We use a large set of the MIMD Lattice Computation Collaboration's gauge configurations with a^{2} tadpole-improved staggered sea quarks and tadpole-improved Lüscher-Weisz gluons. We use the a^{2} tadpole-improved action for valence light quarks and the Sheikoleslami-Wohlert action with the Fermilab interpretation for the valence charm quark. Our calculation covers the complete set of five operators needed to constrain new physics models for D-meson mixing. We match our matrix elements to the MS-NDR scheme evaluated at 3 GeV. We report values for the Beneke-Buchalla-Greub-Lenz-Nierste choice of evanescent operators.
Banik, Subrata; Pal, Sourav; Prasad, M Durga
2010-10-12
An effective operator approach based on the coupled cluster method is described and applied to calculate vibrational expectation values and absolute transition matrix elements. Coupled cluster linear response theory (CCLRT) is used to calculate excited states. The convergence pattern of these properties with the rank of the excitation operator is studied. The method is applied to a water molecule. Arponen-type double similarity transformation in extended coupled cluster (ECCM) framework is also used to generate an effective operator, and the convergence pattern of these properties is compared to the normal coupled cluster (NCCM) approach. It is found that the coupled cluster method provides an accurate description of these quantities for low lying vibrational excited states. The ECCM provides a significant improvement for the calculation of the transition matrix elements.
A new formulation to calculate general HFB matrix elements through the Pfaffian
NASA Astrophysics Data System (ADS)
Mizusaki, Takahiro; Oi, Makito
2012-08-01
A new formula is presented for the calculation of matrix elements between multi-quasiparticle Hartree-Fock-Bogoliubov (HFB) states. The formula is expressed in terms of the Pfaffian, and is derived by using Fermion coherent states with Grassmann numbers. It turns out that the formula corresponds to an extension of the generalized Wick's theorem and simplifies the combinatorial complexity resulting from practical applications of the generalized Wick's theorem by unifying the transition density and the transition pairing tensor in HFB theory. The resultant formula is simpler and more compact than the traditional description of matrix elements of general many-body operators. In addition, through the derivation of our new formula, we found that the Pfaffian version of the Lewis Carroll formula corresponds to a relation suggested by Balian and Brezin for HFB theory in 1969.
Study of matrix crack-tilted fiber bundle interaction using caustics and finite element method.
Hao, Wenfeng; Zhu, Jianguo; Zhu, Qi; Yuan, Yanan
2016-02-01
In this work, the interaction between the matrix crack and a tilted fiber bundle was investigated via caustics and the finite element method (FEM). First, the caustic patterns at the crack tip with different distances from the tilted fiber were obtained and the stress intensity factors were extracted from the geometry of the caustic patterns. Subsequently, the shielding effect of the fiber bundle in front of the crack tip was analyzed. Furthermore, the interaction between the matrix crack and the broken fiber bundle was discussed. Finally, a finite element simulation was carried out using ABAQUS to verify the experimental results. The results demonstrate that the stress intensity factors extracted from caustic experiments are in excellent agreement with the data calculated by FEM.
Determination of electric-dipole matrix elements in K and Rb from Stark shift measurements
Arora, Bindiya; Safronova, M. S.; Clark, Charles W.
2007-11-15
Stark shifts of potassium and rubidium D1 lines have been measured with high precision by Miller et al. [Phys. Rev. A 49, 5128 (1994)]. In this work, we combine these measurements with our all-order calculations to determine the values of the electric-dipole matrix elements for the 4p{sub j}-3d{sub j{sup '}} transitions in K and the 5p{sub j}-4d{sub j{sup '}} transitions in Rb to high precision. The 4p{sub 1/2}-3d{sub 3/2} and 5p{sub 1/2}-4d{sub 3/2} transitions contribute on the order of 90% to the respective polarizabilities of the np{sub 1/2} states in K and Rb, and the remaining 10% can be accurately calculated using the relativistic all-order method. Therefore, the combination of the experimental data and theoretical calculations allows us to determine the np-(n-1)d matrix elements and their uncertainties. We compare these values with our all-order calculations of the np-(n-1)d matrix elements in K and Rb for a benchmark test of the accuracy of the all-order method for transitions involving nd states. Such matrix elements are of special interest for many applications, such as determination of ''magic'' wavelengths in alkali-metal atoms for state-insensitive cooling and trapping, and determination of blackbody radiation shifts in optical frequency standards with ions.
NASA Astrophysics Data System (ADS)
Sarkadi, L.
2017-03-01
The program MTRDCOUL [1] calculates the matrix elements of the Coulomb interaction between a charged particle and an atomic electron, ∫ ψf∗ (r) ∣ R - r∣-1ψi(r) d r. Bound-free transitions are considered, and relativistic hydrogenic wave functions are used. In this revised version a bug discovered in the F3Y CPC Program Library subprogram [2] is fixed.
D'Ariano, G M; Lo Presti, P
2001-05-07
Quantum operations describe any state change allowed in quantum mechanics, including the evolution of an open system or the state change due to a measurement. We present a general method based on quantum tomography for measuring experimentally the matrix elements of an arbitrary quantum operation. As input the method needs only a single entangled state. The feasibility of the technique for the electromagnetic field is shown, and the experimental setup is illustrated based on homodyne tomography of a twin beam.
An improved method for extracting matrix elements from lattice three-point functions
C. Aubin, K. Orginos
2011-12-01
The extraction of matrix elements from baryon three-point functions is complicated by the fact that the signal-to-noise drops rapidly as a function of time. Using a previously discussed method to improve the signal-to-noise for lattice two-point functions, we use this technique to do so for lattice three-point functions, using electromagnetic form factors for the nucleon and Delta as an example.
Useful extremum principle for the variational calculation of matrix elements. II
NASA Technical Reports Server (NTRS)
Gerjuoy, E.; Rosenberg, L.; Spruch, L.
1975-01-01
Recent work (Gerjuoy et al., 1974) on variational principles for diagonal bound state matrix elements of arbitrary Hermitian operators is extended. In particular, it is shown that the previously derived minimum principle for the trial auxiliary function appearing in such variational principles can be constructed using a modified Hamiltonian possessing not heretofore recognized positive definite properties. Thus there is at least one alternative to the particular modified Hamiltonian on which the results of Gerjuoy et al. (1974) originally were based.
Measuring the CKM matrix element V{sub tb} at D-zero and CDF
Heinson, A.P.
1997-07-01
I present measurements by the CDF collaboration of the Standard Model three generation CKM matrix element V{sub tb} and of a special case extension with additional assumptions, using current Tevatron t{anti t} data. I then show how we can significantly improve the precision on V{sub tb} and at the same time extend the measurement so it is not constrained by Standard Model assumptions, using single top production at the upgraded Tevatron.
NASA Astrophysics Data System (ADS)
Günay, E.
2017-02-01
This study defined as micromechanical finite element (FE) approach examining the stress transfer mechanism in single-walled carbon nanotube (SWCN) reinforced composites. In the modeling, 3D unit-cell method was evaluated. Carbon nanotube reinforced composites were modeled as three layers which comprises CNT, interface and matrix material. Firstly; matrix, fiber and interfacial materials all together considered as three layered cylindrical nanocomposite. Secondly, the cylindrical matrix material was assumed to be isotropic and also considered as a continuous medium. Then, fiber material was represented with zigzag type SWCNs. Finally, SWCN was combined with the elastic medium by using springs with different constants. In the FE modeling of SWCN reinforced composite model springs were modeled by using ANSYS spring damper element COMBIN14. The developed interfacial van der Waals interaction effects between the continuous matrix layer and the carbon nanotube fiber layer were simulated by applying these various spring stiffness values. In this study, the layered composite cylindrical FE model was presented as the equivalent mechanical properties of SWCN structures in terms of Young's modulus. The obtained results and literature values were presented and discussed. Figures, 16, 17, and 18 of the original article PDF file, as supplied to AIP Publishing, were affected by a PDF-processing error. Consequently, a solid diamond symbol appeared instead of a Greek tau on the y axis labels for these three figures. This article was updated on 17 March 2017 to correct the PDF-processing error, with the scientific content remaining unchanged.
Spectral element discontinuous Galerkin simulations for wake potential calculations : NEKCEM.
Min, M.; Fischer, P. F.; Chae, Y.-C.
2008-01-01
In this paper we present high-order spectral element discontinuous Galerkin simulations for wake field and wake potential calculations. Numerical discretizations are based on body-conforming hexagonal meshes on Gauss-Lobatto-Legendre grids. We demonstrate wake potential profiles for cylindrically symmetric cavity structures in 3D, including the cases for linear and quadratic transitions between two cross sections. Wake potential calculations are carried out on 2D surfaces for various bunch sizes.
MOON for neutrino-less {beta}{beta} decays and {beta}{beta} nuclear matrix elements
Ejiri, H.
2009-11-09
The MOON project aims at spectroscopic 0v{beta}{beta} studies with the v-mass sensitivity of 100-30 meV by measuring two beta rays from {sup 100}Mo and/or {sup 82}Se. The detector is a compact super-module of multi-layer PL scintillator plates. R and D works made by the pro to-type MOON-1 and the small PL plate show the possible energy resolution of around {sigma}{approx}2.2%, as required for the mass sensitivity. Nuclear matrix elements M{sup 2v} for 2v{beta}{beta} are shown to be given by the sum {sigma}{sub L}M{sub k} of the 2v{beta}{beta} matrix elements M{sub k} through intermediate quasi-particle states in the Fermi-surface, where Mi is obtained experimentally by using the GT(J{sup {pi}} = 1{sup +}) matrix elements of M{sub i}(k) and M{sub f}(k) for the successive single-{beta} transitions through the k-th intermediate state.
Matrix element method at next-to-leading order for arbitrary jet algorithms
NASA Astrophysics Data System (ADS)
Baumeister, Robin; Weinzierl, Stefan
2017-02-01
The matrix element method usually employs leading-order matrix elements. We discuss the generalization towards higher orders in perturbation theory and show how the matrix element method can be used at next-to-leading order for arbitrary infrared-safe jet algorithms. We discuss three variants at next-to-leading order. The first two variants work at the level of the jet momenta. The first variant adheres to strict fixed order in perturbation theory. We present a method for the required integration over the radiation phase space. The second variant is inspired by the POWHEG method and works as the first variant at the level of the jet momenta. The third variant is a more exclusive POWHEG version. Here we resolve exactly one jet into two subjets. If the two subjets are resolved above a scale p⊥min, the likelihood is computed from the POWHEG-modified real emission part, otherwise it is given by the POWHEG-modified virtual part.
MOON for neutrino-less ββ decays and ββ nuclear matrix elements
NASA Astrophysics Data System (ADS)
Ejiri, H.
2009-11-01
The MOON project aims at spectroscopic 0vββ studies with the v-mass sensitivity of 100-30 meV by measuring two beta rays from 100Mo and/or 82Se. The detector is a compact super-module of multi-layer PL scintillator plates. R&D works made by the pro to-type MOON-1 and the small PL plate show the possible energy resolution of around σ~2.2%, as required for the mass sensitivity. Nuclear matrix elements M2v for 2vββ are shown to be given by the sum ΣLMk of the 2vββ matrix elements Mk through intermediate quasi-particle states in the Fermi-surface, where Mi is obtained experimentally by using the GT(Jπ = 1+) matrix elements of Mi(k) and Mf(k) for the successive single-β transitions through the k-th intermediate state.
A triangular element based on generalized potential energy concepts
NASA Technical Reports Server (NTRS)
Thomas, G. R.; Gallagher, R. H.
1976-01-01
Stiffness equations are formulated for a doubly-curved triangular thin shell finite element. The strain energy component of the potential energy is first expressed in terms of displacements and displacement gradients with the aid of consistent deep shell strain-displacement equations. The element in-plane and normal displacement fields are approximated by complete cubic polynomials. These functions do not satisfy the interelement displacement admissibility conditions. Satisfaction is forced by the imposition of constraint conditions on the interelement boundaries; the constraints represent the modification of the potential energy. Some numerical results for a pinched cylinder, a cylindrical sphere, and a pinched sphere are examined.
A Data Matrix Method for Improving the Quantification of Element Percentages of SEM/EDX Analysis
NASA Technical Reports Server (NTRS)
Lane, John
2009-01-01
A simple 2D M N matrix involving sample preparation enables the microanalyst to peer below the noise floor of element percentages reported by the SEM/EDX (scanning electron microscopy/ energy dispersive x-ray) analysis, thus yielding more meaningful data. Using the example of a 2 3 sample set, there are M = 2 concentration levels of the original mix under test: 10 percent ilmenite (90 percent silica) and 20 percent ilmenite (80 percent silica). For each of these M samples, N = 3 separate SEM/EDX samples were drawn. In this test, ilmenite is the element of interest. By plotting the linear trend of the M sample s known concentration versus the average of the N samples, a much higher resolution of elemental analysis can be performed. The resulting trend also shows how the noise is affecting the data, and at what point (of smaller concentrations) is it impractical to try to extract any further useful data.
First ionization potential of the heaviest actinide lawrencium, element 103
NASA Astrophysics Data System (ADS)
Sato, Tetsuya K.; Asai, Masato; Borschevsky, Anastasia; Stora, Thierry; Sato, Nozomi; Kaneya, Yusuke; Tsukada, Kazuaki; Düllmann, Christoph E.; Eberhardt, Klaus; Eliav, Ephraim; Ichikawa, Shinichi; Kaldor, Uzi; Kratz, Jens V.; Miyashita, Sunao; Nagame, Yuichiro; Ooe, Kazuhiro; Osa, Akihiko; Renisch, Dennis; Runke, Jörg; Schädel, Matthias; Thörle-Pospiech, Petra; Toyoshima, Atsushi; Trautmann, Norbert
2016-12-01
The first ionization potential (IP1) of element 103, lawrencium (Lr), has been successfully determined for the first time by using a newly developed method based on a surface ionization process. The measured IP1 value is 4.963 eV. This value is the smallest among those of actinide elements and is in excellent agreement with the value of 4.963(15) eV predicted by state-of-the-art relativistic calculations also performed in this work. Our results strongly support that the Lr atom has an electronic configuration of [Rn]7s25f147p, which is influenced by strong relativistic effects. The present work provides a reliable benchmark for theoretical calculations and also opens the way for studies on atomic properties of heavy elements with atomic number Z > 100. Moreover, the present achievement has triggered a controversy on the position of lutetium (Lu) and Lr in the Periodic Table of Elements.
Evaluation of Solid Modeling Software for Finite Element Analysis of Woven Ceramic Matrix Composites
NASA Technical Reports Server (NTRS)
Nemeth, Noel N.; Mital, Subodh; Lang, Jerry
2010-01-01
Three computer programs, used for the purpose of generating 3-D finite element models of the Repeating Unit Cell (RUC) of a textile, were examined for suitability to model woven Ceramic Matrix Composites (CMCs). The programs evaluated were the open-source available TexGen, the commercially available WiseTex, and the proprietary Composite Material Evaluator (COMATE). A five-harness-satin (5HS) weave for a melt-infiltrated (MI) silicon carbide matrix and silicon carbide fiber was selected as an example problem and the programs were tested for their ability to generate a finite element model of the RUC. The programs were also evaluated for ease-of-use and capability, particularly for the capability to introduce various defect types such as porosity, ply shifting, and nesting of a laminate. Overall, it was found that TexGen and WiseTex were useful for generating solid models of the tow geometry; however, there was a lack of consistency in generating well-conditioned finite element meshes of the tows and matrix. TexGen and WiseTex were both capable of allowing collective and individual shifting of tows within a ply and WiseTex also had a ply nesting capability. TexGen and WiseTex were sufficiently userfriendly and both included a Graphical User Interface (GUI). COMATE was satisfactory in generating a 5HS finite element mesh of an idealized weave geometry but COMATE lacked a GUI and was limited to only 5HS and 8HS weaves compared to the larger amount of weave selections available with TexGen and WiseTex.
Extraction radiopolarography for determining the oxidation potentials of transplutonium elements
Kosyakov, V.N.; Yakovlev, N.G.; Vlasov, M.M.
1987-03-01
A method is described for determining the oxidation potentials for valency transitions in transplutonium elements (TPE), which is usable when the element is present in trace amounts. This is based on electrochemical oxidation or reduction of the TPE in combination with a solvent-extraction method of determining the concentration ratio for the oxidized and reduced forms. The method is applicable to determining the potential of almost any reversible reaction if the solvent-extraction parameters for the oxidized and reduced forms differ substantially, while the potential (with allowance for the extraction system) lies in a region accessible to electrochemical oxidation or reduction. Two forms of use are considered: with liquid extraction and with extraction chromatography. The method is demonstrated on the Bk(IV)/Bk(III) transition with di-2-ethylhexylphosphoric acid as extraction agent.
NASA Astrophysics Data System (ADS)
Sarkadi, L.
2017-03-01
The program MTRXCOUL [1] calculates the matrix elements of the Coulomb interaction between a charged particle and an atomic electron, ∫ψf∗ (r) | R - r | - 1ψi(r) d r. Bound-free transitions are considered, and non-relativistic hydrogenic wave functions are used. In this revised version a bug discovered in the F3Y CPC Program Library (PL) subprogram [2] is fixed. Furthermore, the COULCC CPC PL subprogram [3] applied for the calculations of the radial wave functions of the free states and the Bessel functions is replaced by the CPC PL subprogram DCOUL [4].
Electron-H2 Collisions Studied Using the Finite Element Z-Matrix Method
NASA Technical Reports Server (NTRS)
Huo, Winifred M.; Brown, David; Langhoff, Stephen R. (Technical Monitor)
1997-01-01
We have applied the Z-matrix method, using a mixed basis of finite elements and Gaussians, to study e-H2 elastic and inelastic collisions. Special attention is paid to the quality of the basis set and the treatment of electron correlation. The calculated cross sections are invariant, to machine accuracy, with respect to the choice of parameters a, b, d, e as long as they satisfy Equation (3). However, the log derivative approach, i.e., the choice a = -e = 1, b = d = 0 appears to converge slightly faster than other choices. The cross sections agree well with previous theoretical results. Comparison will be made with available experimental data.
Many-body correlations of QRPA in nuclear matrix elements of double-beta decay
Terasaki, J.
2015-10-28
We present two new ideas on the quasiparticle random-phase approximation (QRPA) approach for calculating nuclear matrix elements of double-beta decay. First, it is necessary to calculate overlaps of the QRPA states obtained on the basis of the ground states of different nuclei. We calculate this overlap using quasiboson vacua as the QRPA ground states. Second, we show that two-particle transfer paths are possible to use for the calculation under the closure approximation. A calculation is shown for {sup 150}Nd→{sup 150}Sm using these two new ideas, and their implication is discussed.
Nuclear matrix elements from direct lifetime or cross-section measurements
Werner, V.; Cooper, N.; Hinton, M.; Ilie, G.; Radeck, D.
2012-11-20
The method of simultaneous lifetime and g factor measurements using a plunger device and the RDDS and TDRIV techniques is introduced. Results on lifetimes and hyperfine-interaction parameters for 2{sup +}{sub 1} states in {sup 104-108}Pd, {sup 96,98,104}Ru, and {sup 92,94}Zr, using a plunger device. Another method to obtain electromagnetic matrix elements is direct cross section measurements using NRF. The method is outlined, and some recent results on {sup 76}Se are shown.
Nucleon matrix elements with Nf=2+1+1 maximally twisted fermions
Simon Dinter, Constantia Alexandrou, Martha Constantinou, Vincent Drach, Karl Jansen, Dru Renner
2010-06-01
We present the first lattice calculation of nucleon matrix elements using four dynamical flavors. We use the Nf=2+1+1 maximally twisted mass formulation. The renormalization is performed non-perturbatively in the RI'-MOM scheme and results are given for the vector and axial vector operators with up to one-derivative. Our calculation of the average momentum of the unpolarized non-singlet parton distribution is presented and compared to our previous results obtained from the Nf=2 case.
Alwall, J.; Hoche, S.; Krauss, F.; Lavesson, N.; Lonnblad, L.; Maltoni, F.; Mangano, M.L.; Moretti, M.; Papadopoulos, C.G.; Piccinini, F.; Schumann, S.; Treccani, M.; Winter, J.; Worek, M.; /SLAC /Durham U., IPPP /Lund U. /Louvain U. /CERN /Ferrara U. /INFN, Ferrara /Athens U. /INFN, Pavia /Dresden, Tech. U. /Karlsruhe U., TP /Silesia U.
2007-06-27
We compare different procedures for combining fixed-order tree-level matrix-element generators with parton showers. We use the case of W-production at the Tevatron and the LHC to compare different implementations of the so-called CKKW and MLM schemes using different matrix-element generators and different parton cascades. We find that although similar results are obtained in all cases, there are important differences.
Measurement of single top quark production at D0 using a matrix element method
Mitrevski, Jovan Pavle
2007-01-01
Until now, the top quark has only been observed produced in pairs, by the strong force. According to the standard model, it can also be produced singly, via an electroweak interaction. Top quarks produced this way provide powerful ways to test the charged-current electroweak interactions of the top quark, to measure |V_{tb}|, and to search for physics beyond the standard model. This thesis describes the application of the matrix element analysis technique to the search for single top quark production with the D0 detector using 0.9 fb^{-1} of Run II data. From a comparison of the matrix element discriminants between data and the background model, assuming a Standard Model s-channel to t-channel cross section ratio of σ_{s}/σ_{t} = 0.44, we measure the single top quark production cross section: σ(p$\\bar{p}$ → tb + X, tqb + X) = 4.8$-1.4\\atop{+1.6}$ pb. This result has a p-value of 0.08%, corresponding to a 3.2 standard deviation Gaussian equivalent significance.
Charge-exchange reactions and nuclear matrix elements for {beta}{beta} decay
Frekers, D.
2009-11-09
Charge-exchange reactions of (n, p) and (p, n) type at intermediate energies are a powerful tool for the study of nuclear matrix element in {beta}{beta} decay. The present paper reviews some of the most recent experiments in this context. Here, the (n, p) type reactions are realized through (d, {sup 2}He), where {sup 2}He refers to two protons in a singlet {sup 1}S{sub 0} state and where both of these are momentum analyzed and detected by the same spectrometer and detector. These reactions have been developed and performed exclusively at KVI, Groningen (NL), using an incident deuteron energy of 183 MeV. Final state resolutions of about 100 keV have routinely been available. On the other hand, the ({sup 3}He, t) reaction is of (p, n) type and was developed at the RCNP facility in Osaka (JP). Measurements with an unprecedented high resolution of 30 keV at incident energies of 420 MeV are now readily possible. Using both reaction types one can extract the Gamow-Teller transition strengths B(GT{sup +}) and B(GT{sup -}), which define the two ''legs'' of the {beta}{beta} decay matrix elements for the 2v{beta}{beta} decay The high resolution available in both reactions allows a detailed insight into the excitations of the intermediate odd-odd nuclei and, as will be shown, some unexpected features are being unveiled.
Determination of color-octet matrix elements from e+e- processes at low energies
NASA Astrophysics Data System (ADS)
Yuan, Feng; Qiao, Cong-Feng; Chao, Kuang-Ta
1997-08-01
We present an analysis of the preliminary experimental data of direct J/ψ production in e+e- processes at low energies. We find that the color-octet contributions are crucially important to the cross section in this energy region, and their inclusion produces a good description of the data. By fitting to the data, we extract the individual values of two color-octet matrix elements:
NASA Astrophysics Data System (ADS)
Monthus, Cécile
2016-07-01
For short-ranged disordered quantum models in one dimension, the many-body-localization is analyzed via the adaptation to the many-body context (Serbyn et al 2015 Phys. Rev. X 5 041047) of the Thouless point of view on the Anderson transition: the question is whether a local interaction between two long chains is able to reshuffle completely the eigenstates (delocalized phase with a volume-law entanglement) or whether the hybridization between tensor states remains limited (many-body-localized phase with an area-law entanglement). The central object is thus the level of hybridization induced by the matrix elements of local operators, as compared with the difference of diagonal energies. The multifractal analysis of these matrix elements of local operators is used to analyze the corresponding statistics of resonances. Our main conclusion is that the critical point is characterized by the strong-multifractality spectrum f(0≤slant α ≤slant 2)=\\fracα{2} , well known in the context of Anderson localization in spaces of effective infinite dimensionality, where the size of the Hilbert space grows exponentially with the volume. Finally, the possibility of a delocalized non-ergodic phase near criticality is discussed.
The Sp(3, R) Sympletic Model: a comparison of exact and approximate matrix elements
NASA Astrophysics Data System (ADS)
McCoy, Anna; Caprio, Mark; Rowe, David
2014-03-01
The Sp(3, R) symplectic model has a close physical connection to both the microscopic shell model and the collective deformation and rotational degrees of freedom, and it is a natural extension of the Elliot SU(3) model from single-shell to multi-shell dynamics. The Sp(3, R) Lie algebra--which contains the angular momentum operators, the quadrupole and vibrational momentum operators and the quadrupole flow tensor operators--is the smallest algebra containing both the shell model Hamiltonian and the rotor algebra. In the limit of large number of oscillator quanta, the Sp(3, R) algebra contracts to the U(3) boson algebra. For large values of the Casimir operator of the SU(3) subalgebra, the sp(3, R) algebra further contracts to the algebra of the collective coupled rotor-vibrator model. The exact Sp(3, R) matrix elements, calculated using the vector coherent state method, are compared with approximate matrix elements calculated in the U(3) boson limit. Science Advancement under a Cottrell Scholar Award and by the US DOE under grant DE-FG02-95ER-40934.
Top quark mass measurement from dilepton events at CDF II with the matrix-element method
Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; /Taiwan, Inst. Phys. /Argonne /Barcelona, IFAE /Baylor U. /INFN, Bologna /Bologna U. /Brandeis U. /UC, Davis /UCLA /UC, San Diego /UC, Santa Barbara
2006-05-01
We describe a measurement of the top quark mass using events with two charged leptons collected by the CDF II detector from p{bar p} collisions with {radical}s = 1.96 TeV at the Fermilab Tevatron. The likelihood in top mass is calculated for each event by convoluting the leading order matrix element describing q{bar q} {yields} t{bar t} {yields} b{ell}{nu}{sub {ell}}{bar b}{ell}{prime} {nu}{sub {ell}}, with detector resolution functions. The presence of background events in the data sample is modeled using similar calculations involving the matrix elements for major background processes. In a data sample with integrated luminosity of 340 pb{sup -1}, we observe 33 candidate events and measure M{sub top} = 165.2 {+-} 6.1(stat.) {+-} 3.4(syst.) GeV/c{sup 2}. This measurement represents the first application of this method to events with two charged leptons and is the most precise single measurement of the top quark mass in this channel.
Precision Measurement of the Neutron Twist-3 Matrix Element dn2: Probing Color Forces
Posik, Matthew; Flay, David; Parno, Diana; Allada, Kalyan; Armstrong, Whitney; Averett, Todd; Benmokhtar, Fatiha; Bertozzi, William; Camsonne, Alexandre; Canan, Mustafa; Cates, Gordon; Chen, Chunhua; Chen, Jian-Ping; Choi, Seonho; Chudakov, Eugene; Cusanno, Francesco; Dalton, Mark; Deconinck, Wouter; De Jager, Cornelis; Deng, Xiaoyan; Deur, Alexandre; Dutta, Chiranjib; El Fassi, Lamiaa; Franklin, Gregg; Friend, Megan; Gao, Haiyan; Garibaldi, Franco; Gilad, Shalev; Gilman, Ronald; Glamazdin, Oleksandr; Golge, Serkan; Gomez, Javier; Guo, Lei; Hansen, Jens-Ole; Higinbotham, Douglas; Holmstrom, Timothy; Huang, J; Hyde, Charles; Ibrahim Abdalla, Hassan; Jiang, Xiaodong; Jin, Ge; Katich, Joseph; Kelleher, Aidan; Kolarkar, Ameya; Korsch, Wolfgang; Kumbartzki, Gerfried; LeRose, John; Lindgren, Richard; Liyanage, Nilanga; Long, Elena; Lukhanin, Oleksandr; Mamyan, Vahe; McNulty, Dustin; Meziani, Zein-Eddine; Michaels, Robert; Mihovilovic, Miha; Moffit, Bryan; Muangma, Navaphon; Nanda, Sirish; Narayan, Amrendra; Nelyubin, Vladimir; Norum, Blaine; Nuruzzaman, nfn; Oh, Yongseok; Peng, Jen-chieh; Qian, Xin; Qiang, Yi; Rakhman, Abdurahim; Riordan, Seamus; Saha, Arunava; Sawatzky, Bradley; Hashemi Shabestari, Mitra; Shahinyan, Albert; Sirca, Simon; Solvignon-Slifer, Patricia; Subedi, Ramesh; Sulkosky, Vincent; Tobias, William; Troth, Wolfgang; Wang, Diancheng; Wang, Y; Wojtsekhowski, Bogdan; Yan, X; Yao, Huan; Ye, Yunxiu; Ye, Zhihong; Yuan, Lulin; Zhan, X; Zhang, Y; Zhang, Y -W; Zhao, Bo; Zheng, Xiaochao
2014-07-01
Double-spin asymmetries and absolute cross sections were measured at large Bjorken x (0.25 lte x lte 0.90), in both the deep-inelastic and resonance regions, by scattering longitudinally polarized electrons at beam energies of 4.7 and 5.9 GeV from a transversely and longitudinally polarized 3He target. In this dedicated experiment, the spin structure function g2 on 3He was determined with precision at large x, and the neutron twist-three matrix element dn2 was measured at ?Q2? of 3.21 and 4.32 GeV2/c2, with an absolute precision of about 10?5. Our results are found to be in agreement with lattice QCD calculations and resolve the disagreement found with previous data at ?Q2?= 5 GeV2/c2. Combining dn2 and a newly extracted twist-four matrix element, fn2, the average neutron color electric and magnetic forces were extracted and found to be of opposite sign and about 60 MeV/fm in magnitude.
Top quark mass measurement in the lepton plus jets channel using a modified matrix element method
NASA Astrophysics Data System (ADS)
Aaltonen, T.; Adelman, J.; Akimoto, T.; González, B. Álvarez; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; Arisawa, T.; Artikov, A.; Ashmanskas, W.; Attal, A.; Aurisano, A.; Azfar, F.; Azzurri, P.; Badgett, W.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Bartsch, V.; Bauer, G.; Beauchemin, P.-H.; Bedeschi, F.; Beecher, D.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Beringer, J.; Bhatti, A.; Binkley, M.; Bisello, D.; Bizjak, I.; Blair, R. E.; Blocker, C.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Boisvert, V.; Bolla, G.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brau, B.; Bridgeman, A.; Brigliadori, L.; Bromberg, C.; Brubaker, E.; Budagov, J.; Budd, H. S.; Budd, S.; Burke, S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Byrum, K. L.; Cabrera, S.; Calancha, C.; Campanelli, M.; Campbell, M.; Canelli, F.; Canepa, A.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chang, S. H.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chou, J. P.; Choudalakis, G.; Chuang, S. H.; Chung, K.; Chung, W. H.; Chung, Y. S.; Chwalek, T.; Ciobanu, C. I.; Ciocci, M. A.; Clark, A.; Clark, D.; Compostella, G.; Convery, M. E.; Conway, J.; Cordelli, M.; Cortiana, G.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Almenar, C. Cuenca; Cuevas, J.; Culbertson, R.; Cully, J. C.; Dagenhart, D.; Datta, M.; Davies, T.; de Barbaro, P.; de Cecco, S.; Deisher, A.; de Lorenzo, G.; Dell'Orso, M.; Deluca, C.; Demortier, L.; Deng, J.; Deninno, M.; Derwent, P. F.; di Giovanni, G. P.; Dionisi, C.; di Ruzza, B.; Dittmann, J. R.; D'Onofrio, M.; Donati, S.; Dong, P.; Donini, J.; Dorigo, T.; Dube, S.; Efron, J.; Elagin, A.; Erbacher, R.; Errede, D.; Errede, S.; Eusebi, R.; Fang, H. C.; Farrington, S.; Fedorko, W. T.; Feild, R. G.; Feindt, M.; Fernandez, J. P.; Ferrazza, C.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Furic, I.; Gallinaro, M.; Galyardt, J.; Garberson, F.; Garcia, J. E.; Garfinkel, A. F.; Genser, K.; Gerberich, H.; Gerdes, D.; Gessler, A.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Gimmell, J. L.; Ginsburg, C. M.; Giokaris, N.; Giordani, M.; Giromini, P.; Giunta, M.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gresele, A.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Grundler, U.; da Costa, J. Guimaraes; Gunay-Unalan, Z.; Haber, C.; Hahn, K.; Hahn, S. R.; Halkiadakis, E.; Han, B.-Y.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harper, S.; Harr, R. F.; Harris, R. M.; Hartz, M.; Hatakeyama, K.; Hays, C.; Heck, M.; Heijboer, A.; Heinrich, J.; Henderson, C.; Herndon, M.; Heuser, J.; Hewamanage, S.; Hidas, D.; Hill, C. S.; Hirschbuehl, D.; Hocker, A.; Hou, S.; Houlden, M.; Hsu, S.-C.; Huffman, B. T.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Incandela, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jha, M. K.; Jindariani, S.; Johnson, W.; Jones, M.; Joo, K. K.; Jun, S. Y.; Jung, J. E.; Junk, T. R.; Kamon, T.; Kar, D.; Karchin, P. E.; Kato, Y.; Kephart, R.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, H. W.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kimura, N.; Kirsch, L.; Klimenko, S.; Knuteson, B.; Ko, B. R.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Korytov, A.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Krumnack, N.; Kruse, M.; Krutelyov, V.; Kubo, T.; Kuhr, T.; Kulkarni, N. P.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; Lazzizzera, I.; Lecompte, T.; Lee, E.; Lee, H. S.; Lee, S. W.; Leone, S.; Lewis, J. D.; Lin, C.-S.; Linacre, J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, T.; Lockyer, N. S.; Loginov, A.; Loreti, M.; Lovas, L.; Lucchesi, D.; Luci, C.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lyons, L.; Lys, J.; Lysak, R.; MacQueen, D.; Madrak, R.; Maeshima, K.; Makhoul, K.; Maki, T.; Maksimovic, P.; Malde, S.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Marino, C. P.; Martin, A.; Martin, V.; Martínez, M.; Martínez-Ballarín, R.; Maruyama, T.; Mastrandrea, P.; Masubuchi, T.; Mathis, M.; Mattson, M. E.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Menzione, A.; Merkel, P.; Mesropian, C.; Miao, T.; Miladinovic, N.; Miller, R.; Mills, C.; Milnik, M.; Mitra, A.; Mitselmakher, G.; Miyake, H.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Fernandez, P. Movilla; Mülmenstädt, J.; Mukherjee, A.; Muller, Th.; Mumford, R.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Nagano, A.; Naganoma, J.; Nakamura, K.; Nakano, I.; Napier, A.; Necula, V.; Nett, J.; Neu, C.; Neubauer, M. S.; Neubauer, S.; Nielsen, J.; Nodulman, L.; Norman, M.; Norniella, O.; Nurse, E.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Osterberg, K.; Griso, S. Pagan; Palencia, E.; Papadimitriou, V.; Papaikonomou, A.; Paramonov, A. A.; Parks, B.; Pashapour, S.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Peiffer, T.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pinera, L.; Pitts, K.; Plager, C.; Pondrom, L.; Poukhov, O.; Pounder, N.; Prakoshyn, F.; Pronko, A.; Proudfoot, J.; Ptohos, F.; Pueschel, E.; Punzi, G.; Pursley, J.; Rademacker, J.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Renz, M.; Rescigno, M.; Richter, S.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Rossi, M.; Rossin, R.; Roy, P.; Ruiz, A.; Russ, J.; Rusu, V.; Saarikko, H.; Safonov, A.; Sakumoto, W. K.; Saltó, O.; Santi, L.; Sarkar, S.; Sartori, L.; Sato, K.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, A.; Schmidt, E. E.; Schmidt, M. A.; Schmidt, M. P.; Schmitt, M.; Schwarz, T.; Scodellaro, L.; Scribano, A.; Scuri, F.; Sedov, A.; Seidel, S.; Seiya, Y.; Semenov, A.; Sexton-Kennedy, L.; Sforza, F.; Sfyrla, A.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shiraishi, S.; Shochet, M.; Shon, Y.; Shreyber, I.; Sidoti, A.; Siegrist, J.; Sinervo, P.; Sisakyan, A.; Slaughter, A. J.; Slaunwhite, J.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Snihur, R.; Soha, A.; Somalwar, S.; Sorin, V.; Spalding, J.; Spreitzer, T.; Squillacioti, P.; Stanitzki, M.; St. Denis, R.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Strycker, G. L.; Stuart, D.; Suh, J. S.; Sukhanov, A.; Suslov, I.; Suzuki, T.; Taffard, A.; Takashima, R.; Takeuchi, Y.; Tanaka, R.; Tecchio, M.; Teng, P. K.; Terashi, K.; Thom, J.; Thompson, A. S.; Thompson, G. A.; Thomson, E.; Tipton, P.; Ttito-Guzmán, P.; Tkaczyk, S.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Tourneur, S.; Trovato, M.; Tsai, S.-Y.; Tu, Y.; Turini, N.; Ukegawa, F.; Vallecorsa, S.; van Remortel, N.; Varganov, A.; Vataga, E.; Vázquez, F.; Velev, G.; Vellidis, C.; Vidal, M.; Vidal, R.; Vila, I.; Vilar, R.; Vine, T.; Vogel, M.; Volobouev, I.; Volpi, G.; Wagner, P.; Wagner, R. G.; Wagner, R. L.; Wagner, W.; Wagner-Kuhr, J.; Wakisaka, T.; Wallny, R.; Wang, S. M.; Warburton, A.; Waters, D.; Weinberger, M.; Weinelt, J.; Wester, W. C., III; Whitehouse, B.; Whiteson, D.; Wicklund, A. B.; Wicklund, E.; Wilbur, S.; Williams, G.; Williams, H. H.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, C.; Wright, T.; Wu, X.; Würthwein, F.; Xie, S.; Yagil, A.; Yamamoto, K.; Yamaoka, J.; Yang, U. K.; Yang, Y. C.; Yao, W. M.; Yeh, G. P.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Yu, S. S.; Yun, J. C.; Zanello, L.; Zanetti, A.; Zhang, X.; Zheng, Y.; Zucchelli, S.
2009-04-01
We report a measurement of the top quark mass, mt, obtained from p pmacr collisions at s=1.96TeV at the Fermilab Tevatron using the CDF II detector. We analyze a sample corresponding to an integrated luminosity of 1.9fb-1. We select events with an electron or muon, large missing transverse energy, and exactly four high-energy jets in the central region of the detector, at least one of which is tagged as coming from a b quark. We calculate a signal likelihood using a matrix element integration method, where the matrix element is modified by using effective propagators to take into account assumptions on event kinematics. Our event likelihood is a function of mt and a parameter JES (jet energy scale) that determines in situ the calibration of the jet energies. We use a neural network discriminant to distinguish signal from background events. We also apply a cut on the peak value of each event likelihood curve to reduce the contribution of background and badly reconstructed events. Using the 318 events that pass all selection criteria, we find mt=172.7±1.8(stat+JES)±1.2(syst)GeV/c2.
Top Quark Mass Measurement in the Lepton plus Jets Channel Using a Modified Matrix Element Method
Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; /Purdue U. /Waseda U.
2008-12-01
The authors report a measurement of the top quark mass, m{sub t}, obtained from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector. They analyze a sample corresponding to an integrated luminosity of 1.9 rfb{sup -1}. They select events with an electron or muon, large missing transverse energy, and exactly four high-energy jets in the central region of the detector, at least one of which is tagged as coming from a b quark. They calculate a signal likelihood using a matrix element integration method, where the matrix element is modified by using effective propagators to take into account assumptions on event kinematics. The event likelihood is a function of m{sub t} and a parameter JES that determines in situ the calibration of the jet energies. They use a neural network discriminant to distinguish signal from background events. They also apply a cut on the peak value of each event likelihood curve to reduce the contribution of background and badly reconstructed events. Using the 318 events that pass all selection criteria, they find m{sub t} = 172.7 {+-} 1.8 (stat. + JES) {+-} 1.2(syst.) GeV/c{sup 2}.
Measurement of the top quark mass in the dilepton final state using the matrix element method
Grohsjean, Alexander
2008-12-15
The top quark, discovered in 1995 by the CDF and D0 experiments at the Fermilab Tevatron Collider, is the heaviest known fundamental particle. The precise knowledge of its mass yields important constraints on the mass of the yet-unobserved Higgs boson and allows to probe for physics beyond the Standard Model. The first measurement of the top quark mass in the dilepton channel with the Matrix Element method at the D0 experiment is presented. After a short description of the experimental environment and the reconstruction chain from hits in the detector to physical objects, a detailed review of the Matrix Element method is given. The Matrix Element method is based on the likelihood to observe a given event under the assumption of the quantity to be measured, e.g. the mass of the top quark. The method has undergone significant modifications and improvements compared to previous measurements in the lepton+jets channel: the two undetected neutrinos require a new reconstruction scheme for the four-momenta of the final state particles, the small event sample demands the modeling of additional jets in the signal likelihood, and a new likelihood is designed to account for the main source of background containing tauonic Z decay. The Matrix Element method is validated on Monte Carlo simulated events at the generator level. For the measurement, calibration curves are derived from events that are run through the full D0 detector simulation. The analysis makes use of the Run II data set recorded between April 2002 and May 2008 corresponding to an integrated luminosity of 2.8 fb^{-1}. A total of 107 t$\\bar{t}$ candidate events with one electron and one muon in the final state are selected. Applying the Matrix Element method to this data set, the top quark mass is measured to be m_{top}^{Run IIa} = 170.6 ± 6.1(stat.)_{-1.5}^{+2.1}(syst.)GeV; m_{top}^{Run IIb} = 174.1 ± 4.4(stat.)_{-1.8}^{+2.5}(syst.)GeV; m
Ceramics and ceramic matrix composites - Aerospace potential and status
NASA Technical Reports Server (NTRS)
Levine, Stanley R.
1992-01-01
Thermostructural ceramics and ceramic-matrix composites are attractive in numerous aerospace applications; the noncatastrophic fracture behavior and flaw-insensitivity of continuous fiber-reinforced CMCs renders them especially desirable. The present development status evaluation notes that, for most highly-loaded high-temperature applications, the requisite fiber-technology base is at present insufficient. In addition to materials processing techniques, the life prediction and NDE methods are immature and require a projection of 15-20 years for the maturity of CMC turbine rotors. More lightly loaded, moderate temperature aircraft engine applications are approaching maturity.
Measurement of the first ionization potential of lawrencium, element 103.
Sato, T K; Asai, M; Borschevsky, A; Stora, T; Sato, N; Kaneya, Y; Tsukada, K; Düllmann, Ch E; Eberhardt, K; Eliav, E; Ichikawa, S; Kaldor, U; Kratz, J V; Miyashita, S; Nagame, Y; Ooe, K; Osa, A; Renisch, D; Runke, J; Schädel, M; Thörle-Pospiech, P; Toyoshima, A; Trautmann, N
2015-04-09
The chemical properties of an element are primarily governed by the configuration of electrons in the valence shell. Relativistic effects influence the electronic structure of heavy elements in the sixth row of the periodic table, and these effects increase dramatically in the seventh row--including the actinides--even affecting ground-state configurations. Atomic s and p1/2 orbitals are stabilized by relativistic effects, whereas p3/2, d and f orbitals are destabilized, so that ground-state configurations of heavy elements may differ from those of lighter elements in the same group. The first ionization potential (IP1) is a measure of the energy required to remove one valence electron from a neutral atom, and is an atomic property that reflects the outermost electronic configuration. Precise and accurate experimental determination of IP1 gives information on the binding energy of valence electrons, and also, therefore, on the degree of relativistic stabilization. However, such measurements are hampered by the difficulty in obtaining the heaviest elements on scales of more than one atom at a time. Here we report that the experimentally obtained IP1 of the heaviest actinide, lawrencium (Lr, atomic number 103), is 4.96(+0.08)(-0.07) electronvolts. The IP1 of Lr was measured with (256)Lr (half-life 27 seconds) using an efficient surface ion-source and a radioisotope detection system coupled to a mass separator. The measured IP1 is in excellent agreement with the value of 4.963(15) electronvolts predicted here by state-of-the-art relativistic calculations. The present work provides a reliable benchmark for theoretical calculations and also opens the way for IP1 measurements of superheavy elements (that is, transactinides) on an atom-at-a-time scale.
Measurement of the first ionization potential of lawrencium, element 103
NASA Astrophysics Data System (ADS)
Sato, T. K.; Asai, M.; Borschevsky, A.; Stora, T.; Sato, N.; Kaneya, Y.; Tsukada, K.; Düllmann, Ch. E.; Eberhardt, K.; Eliav, E.; Ichikawa, S.; Kaldor, U.; Kratz, J. V.; Miyashita, S.; Nagame, Y.; Ooe, K.; Osa, A.; Renisch, D.; Runke, J.; Schädel, M.; Thörle-Pospiech, P.; Toyoshima, A.; Trautmann, N.
2015-04-01
The chemical properties of an element are primarily governed by the configuration of electrons in the valence shell. Relativistic effects influence the electronic structure of heavy elements in the sixth row of the periodic table, and these effects increase dramatically in the seventh row--including the actinides--even affecting ground-state configurations. Atomic s and p1/2 orbitals are stabilized by relativistic effects, whereas p3/2, d and f orbitals are destabilized, so that ground-state configurations of heavy elements may differ from those of lighter elements in the same group. The first ionization potential (IP1) is a measure of the energy required to remove one valence electron from a neutral atom, and is an atomic property that reflects the outermost electronic configuration. Precise and accurate experimental determination of IP1 gives information on the binding energy of valence electrons, and also, therefore, on the degree of relativistic stabilization. However, such measurements are hampered by the difficulty in obtaining the heaviest elements on scales of more than one atom at a time. Here we report that the experimentally obtained IP1 of the heaviest actinide, lawrencium (Lr, atomic number 103), is electronvolts. The IP1 of Lr was measured with 256Lr (half-life 27 seconds) using an efficient surface ion-source and a radioisotope detection system coupled to a mass separator. The measured IP1 is in excellent agreement with the value of 4.963(15) electronvolts predicted here by state-of-the-art relativistic calculations. The present work provides a reliable benchmark for theoretical calculations and also opens the way for IP1 measurements of superheavy elements (that is, transactinides) on an atom-at-a-time scale.
Therapeutic potential of matrix metalloproteinases in Duchenne muscular dystrophy
Ogura, Yuji; Tajrishi, Marjan M.; Sato, Shuichi; Hindi, Sajedah M.; Kumar, Ashok
2014-01-01
Matrix metalloproteinases (MMPs) are secreted proteinases that have physiologic roles in degradation and remodeling of extracellular matrix (ECM) in almost all tissues. However, their excessive production in disease conditions leads to many pathological features including tissue breakdown, inflammation, cell death, and fibrosis. Duchenne Muscular dystrophy (DMD) is a devastating genetic muscle disorder caused by partial or complete loss of cytoskeletal protein dystrophin. Progressive muscle wasting in DMD is accompanied by myofiber necrosis followed by cycles of regeneration and degeneration and inflammation that eventually result in replacement of myofiber by connective and adipose tissues. Emerging evidence suggests that gene expression and the activity of various MMPs are aberrantly regulated in muscle biopsies from DMD patients and in skeletal muscle of animal models of DMD. Moreover, a few studies employing genetic mouse models have revealed that different MMPs play distinct roles in disease progression in DMD. Modulation of the activity of MMPs improves myofiber regeneration and enhances the efficacy of transplantation and engraftment of muscle progenitor cells in dystrophic muscle in mouse models of DMD. Furthermore, recent reports also suggest that some MMPs especially MMP-9 can serve as a biomarker for diagnosis and prognosis of DMD. In this article, we provide a succinct overview of the regulation of various MMPs and their therapeutic importance in DMD. PMID:25364719
Therapeutic potential of matrix metalloproteinases in Duchenne muscular dystrophy.
Ogura, Yuji; Tajrishi, Marjan M; Sato, Shuichi; Hindi, Sajedah M; Kumar, Ashok
2014-01-01
Matrix metalloproteinases (MMPs) are secreted proteinases that have physiologic roles in degradation and remodeling of extracellular matrix (ECM) in almost all tissues. However, their excessive production in disease conditions leads to many pathological features including tissue breakdown, inflammation, cell death, and fibrosis. Duchenne Muscular dystrophy (DMD) is a devastating genetic muscle disorder caused by partial or complete loss of cytoskeletal protein dystrophin. Progressive muscle wasting in DMD is accompanied by myofiber necrosis followed by cycles of regeneration and degeneration and inflammation that eventually result in replacement of myofiber by connective and adipose tissues. Emerging evidence suggests that gene expression and the activity of various MMPs are aberrantly regulated in muscle biopsies from DMD patients and in skeletal muscle of animal models of DMD. Moreover, a few studies employing genetic mouse models have revealed that different MMPs play distinct roles in disease progression in DMD. Modulation of the activity of MMPs improves myofiber regeneration and enhances the efficacy of transplantation and engraftment of muscle progenitor cells in dystrophic muscle in mouse models of DMD. Furthermore, recent reports also suggest that some MMPs especially MMP-9 can serve as a biomarker for diagnosis and prognosis of DMD. In this article, we provide a succinct overview of the regulation of various MMPs and their therapeutic importance in DMD.
ERIC Educational Resources Information Center
Arnold, Randy J.; Arndt, Brett; Blaser, Emilia; Blosser, Chris; Caulton, Dana; Chung, Won Sog; Fiorenza, Garrett; Heath, Wyatt; Jacobs, Alex; Kahng, Eunice; Koh, Eun; Le, Thao; Mandla, Kyle; McCory, Chelsey; Newman, Laura; Pithadia, Amit; Reckelhoff, Anna; Rheinhardt, Joseph; Skljarevski, Sonja; Stuart, Jordyn; Taylor, Cassie; Thomas, Scott; Tse, Kyle; Wall, Rachel; Warkentien, Chad
2011-01-01
A multivitamin tablet and liquid are analyzed for the elements calcium, magnesium, iron, zinc, copper, and manganese using atomic absorption spectrometry. Linear calibration and standard addition are used for all elements except calcium, allowing for an estimate of the matrix effects encountered for this complex sample. Sample preparation using…
Yordanov, D. Lishev, St.; Shivarova, A.
2016-02-15
Combining measurements of the extracted currents with probe and laser-photodetachment diagnostics, the study is an extension of recent tests of factors and gas-discharge conditions stimulating the extraction of volume produced negative ions. The experiment is in a single element of a rf source with the design of a matrix of small-radius inductively driven discharges. The results are for the electron and negative-ion densities, for the plasma potential and for the electronegativity in the vicinity of the plasma electrode as well as for the currents of the extracted negative ions and electrons. The plasma-electrode bias and the rf power have been varied. Necessity of a high bias to the plasma electrode and stable linear increase of the extracted currents with the rf power are the main conclusions.
Latent Regulatory Potential of Human-Specific Repetitive Elements
Ward, Michelle C.; Wilson, Michael D.; Barbosa-Morais, Nuno L.; Schmidt, Dominic; Stark, Rory; Pan, Qun; Schwalie, Petra C.; Menon, Suraj; Lukk, Margus; Watt, Stephen; Thybert, David; Kutter, Claudia; Kirschner, Kristina; Flicek, Paul; Blencowe, Benjamin J.; Odom, Duncan T.
2013-01-01
Summary At least half of the human genome is derived from repetitive elements, which are often lineage specific and silenced by a variety of genetic and epigenetic mechanisms. Using a transchromosomic mouse strain that transmits an almost complete single copy of human chromosome 21 via the female germline, we show that a heterologous regulatory environment can transcriptionally activate transposon-derived human regulatory regions. In the mouse nucleus, hundreds of locations on human chromosome 21 newly associate with activating histone modifications in both somatic and germline tissues, and influence the gene expression of nearby transcripts. These regions are enriched with primate and human lineage-specific transposable elements, and their activation corresponds to changes in DNA methylation at CpG dinucleotides. This study reveals the latent regulatory potential of the repetitive human genome and illustrates the species specificity of mechanisms that control it. PMID:23246434
Modes of occurrence of potentially hazardous elements in coal: levels of confidence
Finkelman, R.B.
1994-01-01
The modes of occurrence of the potentially hazardous elements in coal will be of significance in any attempt to reduce their mobilization due to coal combustion. Antimony and selenium may be present in solid solution in pyrite, as minute accessory sulfides dispersed throughout the organic matrix, or in organic association. Because of these modes of occurrence it is anticipated that less than 50% of these elements will be routinely removed by conventional coal cleaning procedures. Arsenic and mercury occur primarily in late-stage coarse-grained pyrite therefore physical coal cleaning procedures should be successful in removing substantial proportions of these elements. Cadmium occurs in sphalerite and lead in galena. Both of these minerals exhibit a wide range of particle sizes and textural relations. Depending on the particle size and textural relations, physical coal cleaning may remove as little as 25% of these elements or as much as 75%. Manganese in bituminous coal occurs in carbonates, especially siderite. Physical coal cleaning should remove a substantial proportion of this element. More information is needed to elucidate the modes of occurrence of beryllium, chromium, cobalt, and nickel. ?? 1994.
NASA Technical Reports Server (NTRS)
Baumeister, K. J.; Majjigi, R. K.
1979-01-01
A finite element velocity potential program was developed to study acoustic wave propagation in complex geometries. For irrotational flows, relatively low sound frequencies, and plane wave input, the finite element solutions showed significant effects of inlet curvature and flow gradients on the attenuation of a given acoustic liner in a realistic variable area turbofan inlet. The velocity potential approach can not be used to estimate the effects of rotational flow on acoustic propagation, since the potential acoustic disturbances propagate at the speed of the media in sheared flow. Approaches are discussed that are being considered for extending the finite element solution to include the far field, as well as the internal portion of the duct. A new matrix partitioning approach is presented that can be incorporated in previously developed programs to allow the finite element calculation to be marched into the far field. The partitioning approach provided a large reduction in computer storage and running times.
NASA Astrophysics Data System (ADS)
Haddouche, Issam; Cherbi, Lynda
2017-01-01
In this paper, we investigate Surface Plasmon Polaritons (SPPs) in the visible regime at a metal/dielectric interface within two different waveguide structures, the first is a Photonic Crystal Fiber where the Full Vector Finite Element Method (FVFEM) is used and the second is a slab waveguide where the transfer matrix method (TMM) is used. Knowing the diversities between the two methods in terms of speed, simplicity, and scope of application, computation is implemented with respect to wavelength and metal layer thickness in order to analyze and compare the performances of the two methods. Simulation results show that the TMM can be a good approximation for the FVFEM and that SPPs behave more like modes propagating in a semi infinite metal/dielectric structure as metal thickness increases from about 150 nm.
Measurement of the top quark mass using the matrix element technique in dilepton final states
NASA Astrophysics Data System (ADS)
Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Agnew, J. P.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Askew, A.; Atkins, S.; Augsten, K.; Aushev, V.; Aushev, Y.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Borysova, M.; Brandt, A.; Brandt, O.; Brochmann, M.; Brock, R.; Bross, A.; Brown, D.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Cuth, J.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duperrin, A.; Dutt, S.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Fauré, A.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Franc, J.; Fuess, S.; Garbincius, P. H.; Garcia-Bellido, A.; García-González, J. A.; Gavrilov, V.; Geng, W.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Gogota, O.; Golovanov, G.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Holzbauer, J. L.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jeong, M. S.; Jesik, R.; Jiang, P.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kajfasz, E.; Karmanov, D.; Katsanos, I.; Kaur, M.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kumar, A.; Kupco, A.; Kurča, T.; Kuzmin, V. A.; Lammers, S.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lei, X.; Lellouch, J.; Li, D.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Mansour, J.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nguyen, H. T.; Nunnemann, T.; Orduna, J.; Osman, N.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M.-A.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Ratoff, P. N.; Razumov, I.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Sánchez-Hernández, A.; Sanders, M. P.; Santos, A. S.; Savage, G.; Savitskyi, M.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schott, M.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Simak, V.; Skubic, P.; Slattery, P.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stefaniuk, N.; Stoyanova, D. A.; Strauss, M.; Suter, L.; Svoisky, P.; Titov, M.; Tokmenin, V. V.; Tsai, Y.-T.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vasilyev, I. A.; Verkheev, A. Y.; Vertogradov, L. S.; Verzocchi, M.; Vesterinen, M.; Vilanova, D.; Vokac, P.; Wahl, H. D.; Wang, M. H. L. S.; Warchol, J.; Watts, G.; Wayne, M.; Weichert, J.; Welty-Rieger, L.; Williams, M. R. J.; Wilson, G. W.; Wobisch, M.; Wood, D. R.; Wyatt, T. R.; Xie, Y.; Yamada, R.; Yang, S.; Yasuda, T.; Yatsunenko, Y. A.; Ye, W.; Ye, Z.; Yin, H.; Yip, K.; Youn, S. W.; Yu, J. M.; Zennamo, J.; Zhao, T. G.; Zhou, B.; Zhu, J.; Zielinski, M.; Zieminska, D.; Zivkovic, L.; D0 Collaboration
2016-08-01
We present a measurement of the top quark mass in p p ¯ collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7 fb-1 . The matrix element technique is applied to t t ¯ events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton +jets final state of t t ¯ decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain a top quark mass of mt=173.93 ±1.84 GeV .
Single-particle parity-nonconserving matrix elements in {sup 207}Pb
Komives, A.; Knott, J.E.; Leuschner, M.; Szymanski, J.J.; Bowman, J.D.; Jamrisk, D.
1993-10-01
Measurements of the helicity dependence of neutron scattering off of heavy nuclei by the TRIPLE collaboration have yielded multiple parity-nonconserving asymmetries. The asymmetries are predominantly positive, in contradiction to the zero average asymmetry predicted by the statistical model of neutron- nucleus scattering. Theoretical calculations that explain the non-zero average asymmetry require single-particle parity- nonconserving matrix elements 10-100 times larger than those predicted by meson exchange models. We are determining the single-particle parity non-conserving mixing in {sup 207}Pb by measuring the circular polarization of the 1.064 MeV {gamma} ray. The experiment uses a transmission polarimeter and a fast data acquisition system. Initial results are presented.
NASA Astrophysics Data System (ADS)
Hill, Richard J.; Solon, Mikhail P.
2015-02-01
Models of weakly interacting massive particles (WIMPs) specified at the electroweak scale are systematically matched to effective theories at hadronic scales where WIMP-nucleus scattering observables are evaluated. Anomalous dimensions and heavy-quark threshold matching conditions are computed for the complete basis of lowest-dimension effective operators involving quarks and gluons. The resulting QCD renormalization group evolution equations are solved. The status of relevant hadronic matrix elements is reviewed and phenomenological illustrations are given, including details for the computation of the universal limit of nucleon scattering with heavy S U (2 )W×U (1 )Y charged WIMPs. Several cases of previously underestimated hadronic uncertainties are isolated. The results connect arbitrary models specified at the electroweak scale to a basis of nf=3 -flavor QCD operators. The complete basis of operators and Lorentz invariance constraints through order v2/c2 in the nonrelativistic nucleon effective theory are derived.
Measurement of the top quark mass using the matrix element technique in dilepton final states
Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Agnew, J. P.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Askew, A.; Atkins, S.; Augsten, K.; Aushev, V.; Aushev, Y.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Borysova, M.; Brandt, A.; Brandt, O.; Brochmann, M.; Brock, R.; Bross, A.; Brown, D.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M. -C.; Cuth, J.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duperrin, A.; Dutt, S.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Fauré, A.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Franc, J.; Fuess, S.; Garbincius, P. H.; Garcia-Bellido, A.; García-González, J. A.; Gavrilov, V.; Geng, W.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Gogota, O.; Golovanov, G.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J. -F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Holzbauer, J. L.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jeong, M. S.; Jesik, R.; Jiang, P.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kajfasz, E.; Karmanov, D.; Katsanos, I.; Kaur, M.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kumar, A.; Kupco, A.; Kurča, T.; Kuzmin, V. A.; Lammers, S.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lei, X.; Lellouch, J.; Li, D.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Mansour, J.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nguyen, H. T.; Nunnemann, T.; Orduna, J.; Osman, N.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M. -A.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Ratoff, P. N.; Razumov, I.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Sánchez-Hernández, A.; Sanders, M. P.; Santos, A. S.; Savage, G.; Savitskyi, M.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schott, M.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Simak, V.; Skubic, P.; Slattery, P.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stefaniuk, N.; Stoyanova, D. A.; Strauss, M.; Suter, L.; Svoisky, P.; Titov, M.; Tokmenin, V. V.; Tsai, Y. -T.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vasilyev, I. A.; Verkheev, A. Y.; Vertogradov, L. S.; Verzocchi, M.; Vesterinen, M.; Vilanova, D.; Vokac, P.; Wahl, H. D.; Wang, M. H. L. S.; Warchol, J.; Watts, G.; Wayne, M.; Weichert, J.; Welty-Rieger, L.; Williams, M. R. J.; Wilson, G. W.; Wobisch, M.; Wood, D. R.; Wyatt, T. R.; Xie, Y.; Yamada, R.; Yang, S.; Yasuda, T.; Yatsunenko, Y. A.; Ye, W.; Ye, Z.; Yin, H.; Yip, K.; Youn, S. W.; Yu, J. M.; Zennamo, J.; Zhao, T. G.; Zhou, B.; Zhu, J.; Zielinski, M.; Zieminska, D.; Zivkovic, L.
2016-08-18
Here, we present a measurement of the top quark mass in pp collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7 fb^{-1}. The matrix element technique is applied to tt events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton+jets final state of tt decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain a top quark mass of m_{t} = 173.93±1.84 GeV.
A modified Finite Element-Transfer Matrix for control design of space structures
NASA Technical Reports Server (NTRS)
Tan, T.-M.; Yousuff, A.; Bahar, L. Y.; Konstandinidis, M.
1990-01-01
The Finite Element-Transfer Matrix (FETM) method was developed for reducing the computational efforts involved in structural analysis. While being widely used by structural analysts, this method does, however, have certain limitations, particularly when used for the control design of large flexible structures. In this paper, a new formulation based on the FETM method is presented. The new method effectively overcomes the limitations in the original FETM method, and also allows an easy construction of reduced models that are tailored for the control design. Other advantages of this new method include the ability to extract open loop frequencies and mode shapes with less computation, and simplification of the design procedures for output feedback, constrained compensation, and decentralized control. The development of this new method and the procedures for generating reduced models using this method are described in detail and the role of the reduced models in control design is discussed through an illustrative example.
Lattice QCD calculation of the proton decay matrix element in the continuum limit
Tsutsui, N.; Hashimoto, S.; Kaneko, T.; Kuramashi, Y.; Aoki, S.; Kanaya, K.; Taniguchi, Y.; Fukugita, M.; Ishikawa, K-I.; Okawa, M.; Ishizuka, N.; Iwasaki, Y.; Ukawa, A.; Yoshie, T.; Onogi, T.
2004-12-01
We present a quenched lattice QCD calculation of the {alpha} and {beta} parameters of the proton decay matrix element. The simulation is carried out using the Wilson quark action at three values of the lattice spacing in the range a{approx_equal}0.1-0.064 fm to study the scaling violation effect. We find only mild scaling violation when the lattice scale is determined by the nucleon mass. We obtain in the continuum limit, vertical bar {alpha}(NDR,2 GeV) vertical bar=0.0090(09)(+5-19) GeV{sup 3} and vertical bar{beta}(NDR,2 GeV)vertical bar=0.0096(09)(+6-20) GeV{sup 3} with {alpha} and {beta} in a relatively opposite sign, where the first error is statistical and the second is due to the uncertainty in the determination of the physical scale.
Influence of Pairing on the Nuclear Matrix Elements of the Neutrinoless {beta}{beta} Decays
Caurier, E.; Nowacki, F.
2008-02-08
We study in this Letter the neutrinoless double beta decay nuclear matrix elements (NME's) in the framework of the interacting shell model. We analyze them in terms of the total angular momentum of the decaying neutron pair and as a function of the seniority truncations in the nuclear wave functions. This point of view turns out to be very adequate to gauge the accuracy of the NME's predicted by different nuclear models. In addition, it gives back the protagonist role in this process to the pairing interaction, the one which is responsible for the very existence of double beta decay emitters. We show that low seniority approximations, comparable to those implicit in the quasiparticle RPA in a spherical basis, tend to overestimate the NME's in several decays.
Spin dipole nuclear matrix elements for double beta decay nuclei by charge-exchange reactions
NASA Astrophysics Data System (ADS)
Ejiri, H.; Frekers, D.
2016-11-01
Spin dipole (SD) strengths for double beta-decay (DBD) nuclei were studied experimentally for the first time by using measured cross sections of (3He, t) charge-exchange reactions (CERs). Then SD nuclear matrix elements (NMEs) {M}α ({{SD}}) for low-lying 2- states were derived from the experimental SD strengths by referring to the experimental α = GT (Gamow-Teller) and α = F (Fermi) strengths. They are consistent with the empirical NMEs M({{SD}}) based on the quasi-particle model with the empirical effective SD coupling constant. The CERs are used to evaluate the SD NME, which is associated with one of the major components of the neutrino-less DBD NME.
The Matrix Element Method at the LHC: status and prospects for Run II
NASA Astrophysics Data System (ADS)
Wertz, Sébastien
2016-10-01
The Matrix Element Method (MEM) is a powerful multivariate method allowing to maximally exploit the experimental and theoretical information available to an analysis. Applications of the MEM at LHC experiments are discussed, such as searches for rare processes and measurements of properties of the Standard Model Higgs boson. The MadWeight software, allowing for a fast and automated computation of MEM weights for any user- specified process, is briefly reviewed. A new implementation of the MEM in the C++ language, MoMEMta, is presented. Building on MadWeight's tricks to accelerate the calculations, it aims at a much improved modularity and maintainability. Examples of this modularity are discussed: the possibility to compute several weights in parallel (propagation of systematic uncertainties), the Differential MEM (DMEM), and a novel way to search for lion-resonant. New Physics.
Turek, Marko; Spehner, Dominique; Müller, Sebastian; Richter, Klaus
2005-01-01
We present a semiclassical calculation of the generalized form factor Kab(tau) which characterizes the fluctuations of matrix elements of the operators a and b in the eigenbasis of the Hamiltonian of a chaotic system. Our approach is based on some recently developed techniques for the spectral form factor of systems with hyperbolic and ergodic underlying classical dynamics and f = 2 degrees of freedom, that allow us to go beyond the diagonal approximation. First we extend these techniques to systems with f > 2. Then we use these results to calculate Kab(tau). We show that the dependence on the rescaled time tau (time in units of the Heisenberg time) is universal for both the spectral and the generalized form factor. Furthermore, we derive a relation between Kab(tau) and the classical time-correlation function of the Weyl symbols of a and b.
A simple representation of energy matrix elements in terms of symmetry-invariant bases.
Cui, Peng; Wu, Jian; Zhang, Guiqing; Boyd, Russell J
2010-02-01
When a system under consideration has some symmetry, usually its Hamiltonian space can be parallel partitioned into a set of subspaces, which is invariant under symmetry operations. The bases that span these invariant subspaces are also invariant under the symmetry operations, and they are the symmetry-invariant bases. A standard methodology is available to construct a series of generator functions (GFs) and corresponding symmetry-adapted basis (SAB) functions from these symmetry-invariant bases. Elements of the factorized Hamiltonian and overlap matrix can be expressed in terms of these SAB functions, and their simple representations can be deduced in terms of GFs. The application of this method to the Heisenberg spin Hamiltonian is demonstrated.
Measurement of the top quark mass using the matrix element technique in dilepton final states
Abazov, V. M.; Abbott, B.; Acharya, B. S.; ...
2016-08-18
Here, we present a measurement of the top quark mass in pp collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7 fb-1. The matrix element technique is applied to tt events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton+jets final state of tt decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain amore » top quark mass of mt = 173.93±1.84 GeV.« less
Cwik, T.; Jamnejad, V.; Zuffada, C.
1994-12-31
The usefulness of finite element modeling follows from the ability to accurately simulate the geometry and three-dimensional fields on the scale of a fraction of a wavelength. To make this modeling practical for engineering design, it is necessary to integrate the stages of geometry modeling and mesh generation, numerical solution of the fields-a stage heavily dependent on the efficient use of a sparse matrix equation solver, and display of field information. The stages of geometry modeling, mesh generation, and field display are commonly completed using commercially available software packages. Algorithms for the numerical solution of the fields need to be written for the specific class of problems considered. Interior problems, i.e. simulating fields in waveguides and cavities, have been successfully solved using finite element methods. Exterior problems, i.e. simulating fields scattered or radiated from structures, are more difficult to model because of the need to numerically truncate the finite element mesh. To practically compute a solution to exterior problems, the domain must be truncated at some finite surface where the Sommerfeld radiation condition is enforced, either approximately or exactly. Approximate methods attempt to truncate the mesh using only local field information at each grid point, whereas exact methods are global, needing information from the entire mesh boundary. In this work, a method that couples three-dimensional finite element (FE) solutions interior to the bounding surface, with an efficient integral equation (IE) solution that exactly enforces the Sommerfeld radiation condition is developed. The bounding surface is taken to be a surface of revolution (SOR) to greatly reduce computational expense in the IE portion of the modeling.
Potential sources of analytical bias and error in selected trace element data-quality analyses
Paul, Angela P.; Garbarino, John R.; Olsen, Lisa D.; Rosen, Michael R.; Mebane, Christopher A.; Struzeski, Tedmund M.
2016-09-28
Potential sources of analytical bias and error associated with laboratory analyses for selected trace elements where concentrations were greater in filtered samples than in paired unfiltered samples were evaluated by U.S. Geological Survey (USGS) Water Quality Specialists in collaboration with the USGS National Water Quality Laboratory (NWQL) and the Branch of Quality Systems (BQS).Causes for trace-element concentrations in filtered samples to exceed those in associated unfiltered samples have been attributed to variability in analytical measurements, analytical bias, sample contamination either in the field or laboratory, and (or) sample-matrix chemistry. These issues have not only been attributed to data generated by the USGS NWQL but have been observed in data generated by other laboratories. This study continues the evaluation of potential analytical bias and error resulting from matrix chemistry and instrument variability by evaluating the performance of seven selected trace elements in paired filtered and unfiltered surface-water and groundwater samples collected from 23 sampling sites of varying chemistries from six States, matrix spike recoveries, and standard reference materials.Filtered and unfiltered samples have been routinely analyzed on separate inductively coupled plasma-mass spectrometry instruments. Unfiltered samples are treated with hydrochloric acid (HCl) during an in-bottle digestion procedure; filtered samples are not routinely treated with HCl as part of the laboratory analytical procedure. To evaluate the influence of HCl on different sample matrices, an aliquot of the filtered samples was treated with HCl. The addition of HCl did little to differentiate the analytical results between filtered samples treated with HCl from those samples left untreated; however, there was a small, but noticeable, decrease in the number of instances where a particular trace-element concentration was greater in a filtered sample than in the associated
Nuclear-Structure Data Relevant to Neutinoless-Double-Beta-Decay Matrix Elements
NASA Astrophysics Data System (ADS)
Kay, Benjamin
2015-10-01
An observation of neutrinoless double beta decay is one of the most exciting prospects in contemporary physics. It follows that calculations of the nuclear matrix elements for this process are of high priority. The change in the wave functions between the initial and final states of the neutrinoless-double-beta-decay candidates 76Ge-->76Se, 100Mo-->100Ru, 130Te-->130Xe, and 136Xe-->136Ba have been studied with transfer reactions. The data are focused on the change in the occupancies of the valence orbitals in the ground states as two neutrons decay into two protons. The results set a strict constraint on any theoretical calculations describing this rearrangement and thus on the magnitude of the nuclear matrix elements for this process, which currently exhibit uncertainties at the factor of 2-4 level. Prior to these measurements there were limited experimental data were available A = 76 and 100 systems, and very limited data for the A = 130 and 136 systems, in a large part due to the gaseous Xe isotopes involved. The uncertainties on most of these data are estimated to range from 0.1-0.3 nucleons. The program started with the A = 76 system, with subsequent calculations, modified to reproduce the experimental occupancies, exhibiting a significant reduction in the discrepancy between various models. New data are available for the A = 100 , 130, and 136 systems. I review the program, making detailed comparisons between the latest theoretical calculations and the experimental data where available. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract Number DE-AC02-06CH11357.
Minimizing matrix effect by femtosecond laser ablation and ionization in elemental determination.
Zhang, Bochao; He, Miaohong; Hang, Wei; Huang, Benli
2013-05-07
Matrix effect is unavoidable in direct solid analysis, which usually is a leading cause of the nonstoichiometric effect in quantitative analysis. In this research, experiments were carried out to study the overall characteristics of atomization and ionization in laser-solid interaction. Both nanosecond (ns) and femtosecond (fs) lasers were applied in a buffer-gas-assisted ionization source coupled with an orthogonal time-of-flight mass spectrometer. Twenty-nine solid standards of ten different matrices, including six metals and four dielectrics, were analyzed. The results indicate that the fs-laser mode offers more stable relative sensitivity coefficients (RSCs) with irradiance higher than 7 × 10(13) W·cm(-2), which could be more reliable in the determination of element composition of solids. The matrix effect is reduced by half when the fs-laser is employed, owing to the fact that the fs-laser ablation and ionization (fs-LAI) incurs an almost heat-free ablation process and creates a dense plasma for the stable ionization.
Leptonic CP phase determined by an equation involving PMNS matrix elements
NASA Astrophysics Data System (ADS)
Ke, Hong-Wei; Zhou, Jia-Hui; Li, Xue-Qian
2017-04-01
Several approximate equalities among the matrix elements of the Cabibbo–Kobayashi–Maskawa (CKM) and Pontecorvo–Maki–Nakagawa–Sakata (PMNS) matrices imply that hidden symmetries may exist and be common for both quark and neutrino sectors. The charge parity (CP) phase of the CKM matrix ({δ }{CKM}) is involved in these equalities and can be investigated when these equalities turn into several equations. As we substitute those experimentally measured values of the three mixing angles into the equations for quarks, it is noted that one of the equations which holds exactly has a solution {δ }{CKM}=({68.95}-1.15+1.15)^\\circ . That value accords with ({69.1}-3.85+2.02)^\\circ determined from available data. Generalizing the scenario to the lepton sector, the same equality determines the leptonic CP phase {δ }{PMNS} to be ({275.20}-1.15+1.15)^\\circ . Thus we predict the value of {δ }{PMNS} from the equation. So far there is no direct measurement on {δ }{PMNS}, but a recent analysis based on the neutrino oscillation data prefers a phase close to 270°.
Open-Ended Recursive Approach for the Calculation of Multiphoton Absorption Matrix Elements.
Friese, Daniel H; Beerepoot, Maarten T P; Ringholm, Magnus; Ruud, Kenneth
2015-03-10
We present an implementation of single residues for response functions to arbitrary order using a recursive approach. Explicit expressions in terms of density-matrix-based response theory for the single residues of the linear, quadratic, cubic, and quartic response functions are also presented. These residues correspond to one-, two-, three- and four-photon transition matrix elements. The newly developed code is used to calculate the one-, two-, three- and four-photon absorption cross sections of para-nitroaniline and para-nitroaminostilbene, making this the first treatment of four-photon absorption in the framework of response theory. We find that the calculated multiphoton absorption cross sections are not very sensitive to the size of the basis set as long as a reasonably large basis set with diffuse functions is used. The choice of exchange-correlation functional, however, significantly affects the calculated cross sections of both charge-transfer transitions and other transitions, in particular, for the larger para-nitroaminostilbene molecule. We therefore recommend the use of a range-separated exchange-correlation functional in combination with the augmented correlation-consistent double-ζ basis set aug-cc-pVDZ for the calculation of multiphoton absorption properties.
Open-Ended Recursive Approach for the Calculation of Multiphoton Absorption Matrix Elements
2015-01-01
We present an implementation of single residues for response functions to arbitrary order using a recursive approach. Explicit expressions in terms of density-matrix-based response theory for the single residues of the linear, quadratic, cubic, and quartic response functions are also presented. These residues correspond to one-, two-, three- and four-photon transition matrix elements. The newly developed code is used to calculate the one-, two-, three- and four-photon absorption cross sections of para-nitroaniline and para-nitroaminostilbene, making this the first treatment of four-photon absorption in the framework of response theory. We find that the calculated multiphoton absorption cross sections are not very sensitive to the size of the basis set as long as a reasonably large basis set with diffuse functions is used. The choice of exchange–correlation functional, however, significantly affects the calculated cross sections of both charge-transfer transitions and other transitions, in particular, for the larger para-nitroaminostilbene molecule. We therefore recommend the use of a range-separated exchange–correlation functional in combination with the augmented correlation-consistent double-ζ basis set aug-cc-pVDZ for the calculation of multiphoton absorption properties. PMID:25821415
Improved EPMA Trace Element Accuracy Using a Matrix Iterated Quantitative Blank Correction
NASA Astrophysics Data System (ADS)
Donovan, J. J.; Wark, D. A.; Jercinovic, M. J.
2007-12-01
At trace element levels below several hundred PPM, accuracy is more often the limiting factor for EPMA quantification rather than precision. Modern EPMA instruments equipped with low noise detectors, counting electronics and large area analyzing crystals can now routinely achieve sensitivities for most elements in the 10 to 100 PPM levels (or even lower). But due to various sample and instrumental artifacts in the x-ray continuum, absolute accuracy is often the limiting factor for ultra trace element quantification. These artifacts have various mechanisms, but are usually attributed to sample artifacts (e.g., sample matrix absorption edges)1, detector artifacts (e.g., Ar or Xe absorption edges) 2 and analyzing crystal artifacts (extended peak tails preventing accurate determination of the true background and ¡§negative peaks¡¨ or ¡§holes¡¨ in the x-ray continuum). The latter being first described3 by Self, et al. and recently documented for the Ti kÑ in quartz geo-thermometer. 4 Ti (ka) Ti (ka) Ti (ka) Ti (ka) Ti (ka) Si () O () Total Average: -.00146 -.00031 -.00180 .00013 .00240 46.7430 53.2563 99.9983 Std Dev: .00069 .00075 .00036 .00190 .00117 .00000 .00168 .00419 The general magnitude of these artifacts can be seen in the above analyses of Ti ka in a synthetic quartz standard. The values for each spectrometer/crystal vary systematically from ¡V18 PPM to + 24 PPM. The exact mechanism for these continuum ¡§holes¡¨ is not known but may be related to secondary lattice diffraction occurring at certain Bragg angles depending on crystal mounting orientation for non-isometric analyzing crystals5. These x-ray continuum artifacts can produce systematic errors at levels up to 100 PPM or more depending on the particular analytical situation. In order to correct for these inaccuracies, a ¡§blank¡¨ correction has been developed that applies a quantitative correction to the measured x-ray intensities during the matrix iteration, by calculating the intensity
Heavy-ion double charge exchange reactions: A tool toward 0 νββ nuclear matrix elements
NASA Astrophysics Data System (ADS)
Cappuzzello, F.; Cavallaro, M.; Agodi, C.; Bondì, M.; Carbone, D.; Cunsolo, A.; Foti, A.
2015-11-01
The knowledge of the nuclear matrix elements for the neutrinoless double beta decay is fundamental for neutrino physics. In this paper, an innovative technique to extract information on the nuclear matrix elements by measuring the cross section of a double charge exchange nuclear reaction is proposed. The basic point is that the initial- and final-state wave functions in the two processes are the same and the transition operators are similar. The double charge exchange cross sections can be factorized in a nuclear structure term containing the matrix elements and a nuclear reaction factor. First pioneering experimental results for the 40Ca(18O,18Ne)40Ar reaction at 270 MeV incident energy show that such cross section factorization reasonably holds for the crucial 0+ → 0+ transition to 40Args, at least at very forward angles.
Matrix elements in the coupled-cluster approach - With application to low-lying states in Li
NASA Technical Reports Server (NTRS)
Martensson-Pendrill, Ann-Marie; Ynnerman, Anders
1990-01-01
A procedure is suggested for evaluating matrix elements of an operator between wavefunctions in the coupled-cluster form. The use of the exponential ansatz leads to compact exponential expressions also for matrix elements. Algorithms are developed for summing all effects of one-particle clusters and certain chains of two-particle clusters (containing the well-known random-phase approximation as a subset). The treatment of one-particle perturbations in single valence states is investigated in detail. As examples the oscillator strength for the 2s-2p transition in Li as well as the hyperfine structure for the two states are studied and compared to earlier work.
NASA Technical Reports Server (NTRS)
Sanfeliz, Jose G.
1993-01-01
Micromechanical modeling via elastic-plastic finite element analyses were performed to investigate the effects that the residual stresses and the degree of matrix work hardening (i.e., cold-worked, annealed) have upon the behavior of a 9 vol percent, unidirectional W/Cu composite, undergoing tensile loading. The inclusion of the residual stress-containing state as well as the simulated matrix material conditions proved to be significant since the Cu matrix material exhibited plastic deformation, which affected the subsequent tensile response of the composite system. The stresses generated during cooldown to room temperature from the manufacturing temperature were more of a factor on the annealed-matrix composite, since they induced the softened matrix to plastically flow. This event limited the total load-carrying capacity of this matrix-dominated, ductile-ductile type material system. Plastic deformation of the hardened-matrix composite during the thermal cooldown stage was not considerable, therefore, the composite was able to sustain a higher stress before showing any appreciable matrix plasticity. The predicted room temperature, stress-strain response, and deformation stages under both material conditions represented upper and lower bounds characteristic of the composite's tensile behavior. The initial deformation stage for the hardened material condition showed negligible matrix plastic deformation while for the annealed state, its initial deformation stage showed extensive matrix plasticity. Both material conditions exhibited a final deformation stage where the fiber and matrix were straining plastically. The predicted stress-strain results were compared to the experimental, room temperature, tensile stress-strain curve generated from this particular composite system. The analyses indicated that the actual thermal-mechanical state of the composite's Cu matrix, represented by the experimental data, followed the annealed material condition.
Potentially toxic element release by fenton oxidation of sewage sludge.
Andrews, J P; Asaadi, M; Clarke, B; Ouki, S
2006-01-01
The presence, in sewage sludge, of excess levels of the potentially toxic elements (PTE) copper, zinc, chromium, cadmium, nickel, lead and mercury, could impact on our ability to recycle these residues in the future. Far stricter limits on the levels of PTEs are likely in proposed legislation. A method involving the dosing of Fenton's reagent, a mixture of ferrous iron and hydrogen peroxide, under acidic conditions was evaluated for its potential to reduce metal levels. The [Fe]:[H2O2] (w/w) ratio was found to give a good indication of the percentage copper and zinc elution obtainable. Sites with no iron dosing as part of wastewater treatment required extra iron to be added in order to initiate the Fenton's reaction. A significant reduction, in excess of 70%, of the copper and zinc was eluted from both raw primary and activated sludge solid fractions. Cadmium and nickel could be reduced to below detection limits but elution of mercury, lead and chromium was less than 40%. The iron catalyst concentration was found to be a crucial parameter. This process has the potential to reduce the heavy metal content of the sludge and allow the recycling of sludge to continue in a sustainable manner.
Zinc: an essential trace element with potential benefits to soldiers.
McClung, James P; Scrimgeour, Angus G
2005-12-01
Zinc is a trace element known to be an essential nutrient for life. It functions as a cofactor for numerous enzymes, including those involved in DNA and RNA replication and protein synthesis. Soldiers represent a unique population faced with intense metabolic and mental demands, as well as exposure to various immune challenges. Some of these factors may affect their dietary zinc requirements. Although severe zinc deficiency is unlikely to occur, some soldiers may experience less than optimal zinc status because of diminished intake coupled with increased requirements. For those soldiers, supplemental dietary zinc may serve a protective function in numerous disease states affecting modern warfighters. This review highlights the importance of adequate zinc nutriture to soldiers and discusses the potential benefits of supplemental zinc in a number of diseases currently affecting soldiers, including diarrhea, respiratory diseases, malaria, and leishmaniasis.
LATTICE MATRIX ELEMENTS AND CP VIOLATION IN B AND KA PHYSICS: STATUS AND OUTLOOK.
SONI,A.
2003-01-03
Status of lattice calculations of hadron matrix elements along with CP violation in B and in K systems is reviewed. Lattice has provided useful input which, in conjunction with experimental data, leads to the conclusion that CP-odd phase in the CKM matrix plays the dominant role in the observed asymmetry in B {yields} {psi}K{sub s}. It is now quite likely that any beyond the SM, CP-odd, phase will cause only small deviations in B-physics. Search for the effects of the new phase(s) will consequently require very large data samples as well as very precise theoretical predictions. Clean determination of all the angles of the unitarity triangle therefore becomes essential. In this regard B {yields} KD{sup 0} processes play a unique role. Regarding K-decays, remarkable progress made by theory with regard to maintenance of chiral symmetry on the lattice is briefly discussed. First application already provide quantitative information on B{sub K} and the {Delta}I = 1/2 rule. The enhancement in ReA{sub 0} appears to arise solely from tree operators, esp. Q{sub 2}; penguin contribution to ReA{sub 0} appears to be very small. However, improved calculations are necessary for {epsilon}{prime}/{epsilon} as there the contributions of QCD penguins and electroweak penguins largely seem to cancel. There are good reasons, though, to believe that these cancellations will not survive improvements that are now underway. Importance of determining the unitarity triangle purely from K-decays is also emphasized.
Attur, Mukundan; Yang, Qing; Shimada, Kohei; Tachida, Yuki; Nagase, Hiroyuki; Mignatti, Paolo; Statman, Lauren; Palmer, Glyn; Kirsch, Thorsten; Beier, Frank; Abramson, Steven B.
2015-01-01
We investigated the role of periostin, an extracellular matrix protein, in the pathophysiology of osteoarthritis (OA). In OA, dysregulated gene expression and phenotypic changes in articular chondrocytes culminate in progressive loss of cartilage from the joint surface. The molecular mechanisms underlying this process are poorly understood. We examined periostin expression by immunohistochemical analysis of lesional and nonlesional cartilage from human and rodent OA knee cartilage. In addition, we used small interfering (si)RNA and adenovirus transduction of chondrocytes to knock down and up-regulate periostin levels, respectively, and analyzed its effect on matrix metalloproteinase (MMP)-13, a disintegrin and MMP with thrombospondin motifs (ADAMTS)-4, and type II collagen expression. We found high periostin levels in human and rodent OA cartilage. Periostin increased MMP-13 expression dose [1–10 µg/ml (EC50 0.5–1 μg/ml)] and time (24–72 h) dependently, significantly enhanced expression of ADAMTS4 mRNA, and promoted cartilage degeneration through collagen and proteoglycan degradation. Periostin induction of MMP-13 expression was inhibited by CCT031374 hydrobromide, an inhibitor of the canonical Wnt/β-catenin signaling pathway. In addition, siRNA-mediated knockdown of endogenous periostin blocked constitutive MMP-13 expression. These findings implicate periostin as a catabolic protein that promotes cartilage degeneration in OA by up-regulating MMP-13 through canonical Wnt signaling.—Attur, M., Yang, Q., Shimada, K., Tachida, Y., Nagase, H., Mignatti, P., Statman, L., Palmer, G., Kirsch, T., Beier, F., Abramson, A. B. Elevated expression of periostin in human osteoarthritic cartilage and its potential role in matrix degradation via matrix metalloproteinase-13. PMID:26092928
NASA Astrophysics Data System (ADS)
Angeli, C.; Cimiraglia, R.
2013-02-01
A symbolic program performing the Formal Reduction of Density Operators (FRODO), formerly developed in the MuPAD computer algebra system with the purpose of evaluating the matrix elements of the electronic Hamiltonian between internally contracted functions in a complete active space (CAS) scheme, has been rewritten in Mathematica. New version : A program summaryProgram title: FRODO Catalogue identifier: ADV Y _v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADVY_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 3878 No. of bytes in distributed program, including test data, etc.: 170729 Distribution format: tar.gz Programming language: Mathematica Computer: Any computer on which the Mathematica computer algebra system can be installed Operating system: Linux Classification: 5 Catalogue identifier of previous version: ADV Y _v1_0 Journal reference of previous version: Comput. Phys. Comm. 171(2005)63 Does the new version supersede the previous version?: No Nature of problem. In order to improve on the CAS-SCF wavefunction one can resort to multireference perturbation theory or configuration interaction based on internally contracted functions (ICFs) which are obtained by application of the excitation operators to the reference CAS-SCF wavefunction. The previous formulation of such matrix elements in the MuPAD computer algebra system, has been rewritten using Mathematica. Solution method: The method adopted consists in successively eliminating all occurrences of inactive orbital indices (core and virtual) from the products of excitation operators which appear in the definition of the ICFs and in the electronic Hamiltonian expressed in the second quantization formalism. Reasons for new version: Some years ago we published in this journal a couple of papers [1, 2
Characterization of metal matrix composites by linear ultrasonics and finite element modeling.
Chen, Xuesheng; Sharples, Steve D; Clark, Matt; Wright, David
2013-02-01
Titanium metal matrix composites (TiMMCs) offer advantages over traditional materials for aerospace applications due to the increased mechanical strength of the materials. But the non-destructive inspection of these materials, especially with ultrasound, is in an infancy stage. If the manufacturing process of TiMMC is not correctly controlled, then disbonds and voids between the fibers can result. The effective microstructure of the composite makes difficulty to interpret results from traditional ultrasound techniques because of the scattering caused by fibers; the scattering prevents the ultrasound from penetrating far into the composite region and produces a background signal masking any reflections from voids. In this paper, relatively low frequency ultrasound is used to probe the composite region, and the state of the composite (porosity) is inferred from the velocity of the ultrasound traversing the composite. The relationship between the velocity and porosity is complex in this regime, so finite element (FE) analysis is used to model the composite regions and relate the velocity to the porosity. The FE simulated results are validated by ultrasound velocity measurements.
NASA Astrophysics Data System (ADS)
Ablinger, J.; Behring, A.; Blümlein, J.; De Freitas, A.; von Manteuffel, A.; Schneider, C.
2016-05-01
Three loop ladder and V-topology diagrams contributing to the massive operator matrix element AQg are calculated. The corresponding objects can all be expressed in terms of nested sums and recurrences depending on the Mellin variable N and the dimensional parameter ε. Given these representations, the desired Laurent series expansions in ε can be obtained with the help of our computer algebra toolbox. Here we rely on generalized hypergeometric functions and Mellin-Barnes representations, on difference ring algorithms for symbolic summation, on an optimized version of the multivariate Almkvist-Zeilberger algorithm for symbolic integration, and on new methods to calculate Laurent series solutions of coupled systems of differential equations. The solutions can be computed for general coefficient matrices directly for any basis also performing the expansion in the dimensional parameter in case it is expressible in terms of indefinite nested product-sum expressions. This structural result is based on new results of our difference ring theory. In the cases discussed we deal with iterative sum- and integral-solutions over general alphabets. The final results are expressed in terms of special sums, forming quasi-shuffle algebras, such as nested harmonic sums, generalized harmonic sums, and nested binomially weighted (cyclotomic) sums. Analytic continuations to complex values of N are possible through the recursion relations obeyed by these quantities and their analytic asymptotic expansions. The latter lead to a host of new constants beyond the multiple zeta values, the infinite generalized harmonic and cyclotomic sums in the case of V-topologies.
Menéndez, Javier
2013-12-30
We explore the theoretical uncertainties related to the transition operator of neutrinoless double-beta (0νββ) decay. The transition operator used in standard calculations is a product of one-body currents, that can be obtained phenomenologically as in Tomoda [1] or Šimkovic et al. [2]. However, corrections to the operator are hard to obtain in the phenomenological approach. Instead, we calculate the 0νββ decay operator in the framework of chiral effective theory (EFT), which gives a systematic order-by-order expansion of the transition currents. At leading orders in chiral EFT we reproduce the standard one-body currents of Refs. [1] and [2]. Corrections appear as two-body (2b) currents predicted by chiral EFT. We compute the effects of the leading 2b currents to the nuclear matrix elements of 0νββ decay for several transition candidates. The 2b current contributions are related to the quenching of Gamow-Teller transitions found in nuclear structure calculations.
A measurement of the top quark mass with a matrix element method
Gibson, Adam Paul
2006-01-01
The authors present a measurement of the mass of the top quark. The event sample is selected from proton-antiproton collisions, at 1.96 TeV center-of-mass energy, observed with the CDF detector at Fermilab's Tevatron. They consider a 318 pb^{-1} dataset collected between March 2002 and August 2004. They select events that contain one energetic lepton, large missing transverse energy, exactly four energetic jets, and at least one displaced vertex b tag. The analysis uses leading-order t$\\bar{t}$ and background matrix elements along with parameterized parton showering to construct event-by-event likelihoods as a function of top quark mass. From the 63 events observed with the 318 pb^{-1} dataset they extract a top quark mass of 172.0 ± 2.6(stat) ± 3.3(syst) GeV/c^{2} from the joint likelihood. The mean expected statistical uncertainty is 3.2 GeV/c^{2} for m $\\bar{t}$ = 178 GTeV/c^{2} and 3.1 GeV/c^{2} for m $\\bar{t}$ = 172.5 GeV/c^{2}. The systematic error is dominated by the uncertainty of the jet energy scale.
NASA Technical Reports Server (NTRS)
Jenkins, J. M.; Taylor, A. H.; Sakata, I. F.
1985-01-01
A hybrid spar of titanium with an integrally brazed composite, consisting of an aluminum matrix reinforced with boron-carbide-coated fibers, was heated in an oven and the resulting thermal stresses were measured. Uniform heating of the spar in an oven resulted in thermal stresses arising from the effects of dissimilar materials and anisotropy of the metal matrix composite. Thermal stresses were calculated from a finite element structural model using anisotropic material properties deduced from constituent properties and rules of mixtures. Comparisons of calculated thermal stresses with measured thermal stresses on the spar are presented. It was shown that failure to account for anisotropy in the metal matrix composite elements would result in large errors in correlating measured and calculated thermal stresses. It was concluded that very strong material characterization efforts are required to predict accurate thermal stresses in anisotropic composite structures.
Hollaus, K; Magele, C; Merwa, R; Scharfetter, H
2004-02-01
Magnetic induction tomography of biological tissue is used to reconstruct the changes in the complex conductivity distribution by measuring the perturbation of an alternating primary magnetic field. To facilitate the sensitivity analysis and the solution of the inverse problem a fast calculation of the sensitivity matrix, i.e. the Jacobian matrix, which maps the changes of the conductivity distribution onto the changes of the voltage induced in a receiver coil, is needed. The use of finite differences to determine the entries of the sensitivity matrix does not represent a feasible solution because of the high computational costs of the basic eddy current problem. Therefore, the reciprocity theorem was exploited. The basic eddy current problem was simulated by the finite element method using symmetric tetrahedral edge elements of second order. To test the method various simulations were carried out and discussed.
NASA Astrophysics Data System (ADS)
Oberhofer, Harald; Blumberger, Jochen
2010-12-01
We present a plane wave basis set implementation for the calculation of electronic coupling matrix elements of electron transfer reactions within the framework of constrained density functional theory (CDFT). Following the work of Wu and Van Voorhis [J. Chem. Phys. 125, 164105 (2006)], the diabatic wavefunctions are approximated by the Kohn-Sham determinants obtained from CDFT calculations, and the coupling matrix element calculated by an efficient integration scheme. Our results for intermolecular electron transfer in small systems agree very well with high-level ab initio calculations based on generalized Mulliken-Hush theory, and with previous local basis set CDFT calculations. The effect of thermal fluctuations on the coupling matrix element is demonstrated for intramolecular electron transfer in the tetrathiafulvalene-diquinone (Q-TTF-Q-) anion. Sampling the electronic coupling along density functional based molecular dynamics trajectories, we find that thermal fluctuations, in particular the slow bending motion of the molecule, can lead to changes in the instantaneous electron transfer rate by more than an order of magnitude. The thermal average, ( {< {| {H_ab } |^2 } > } )^{1/2} = 6.7 {mH}, is significantly higher than the value obtained for the minimum energy structure, | {H_ab } | = 3.8 {mH}. While CDFT in combination with generalized gradient approximation (GGA) functionals describes the intermolecular electron transfer in the studied systems well, exact exchange is required for Q-TTF-Q- in order to obtain coupling matrix elements in agreement with experiment (3.9 mH). The implementation presented opens up the possibility to compute electronic coupling matrix elements for extended systems where donor, acceptor, and the environment are treated at the quantum mechanical (QM) level.
NASA Technical Reports Server (NTRS)
Duffy, Stephen F.
1998-01-01
The development of modeling approaches for the failure analysis of ceramic-based material systems used in high temperature environments was the primary objective of this research effort. These materials have the potential to support many key engineering technologies related to the design of aeropropulsion systems. Monolithic ceramics exhibit a number of useful properties such as retention of strength at high temperatures, chemical inertness, and low density. However, the use of monolithic ceramics has been limited by their inherent brittleness and a large variation in strength. This behavior has motivated material scientists to reinforce the monolithic material with a ceramic fiber. The addition of a second ceramic phase with an optimized interface increases toughness and marginally increases strength. The primary purpose of the fiber is to arrest crack growth, not to increase strength. The material systems of interest in this research effort were laminated ceramic matrix composites, as well as two- and three- dimensional fabric reinforced ceramic composites. These emerging composite systems can compete with metals in many demanding applications. However, the ongoing metamorphosis of ceramic composite material systems, and the lack of standardized design data has in the past tended to minimize research efforts related to structural analysis. Many structural components fabricated from ceramic matrix composites (CMC) have been designed by "trial and error." The justification for this approach lies in the fact that during the initial developmental phases for a material system fabrication issues are paramount. Emphasis is placed on demonstrating feasibility rather than fully understanding the processes controlling mechanical behavior. This is understandable during periods of rapid improvements in material properties for any composite system. But to avoid the ad hoc approach, the analytical methods developed under this effort can be used to develop rational structural
Poles of the S-matrix in Woods-Saxon and Salamon-Vertse potentials
NASA Astrophysics Data System (ADS)
Vertse, T.; Lovas, R. G.; Salamon, P.; Rácz, A.
2012-10-01
The motions of the l = 0 poles of the S-matrix with varying potential strength is calculated in a cut-off Woods-Saxon (CWS) potential and in the Salamon-Vertse (SV) potential [3]. Both potentials are zero beyond a certain finite distance but the CWS potential has a jump at the cut while the SV potential goes to zero smoothly. The jump of the CWS potential might cause a strange circling of the trajectories at their starting region. This feature does not appear with the SV potential. Starting points of the trajectories depend on the ranges of the potentials. For CWS these points do depend on the unphysical cut-off radius. In this respect the SV potential seems to be superior to the CWS potential.
NASA Astrophysics Data System (ADS)
Sturtz, Timothy M.
Source apportionment models attempt to untangle the relationship between pollution sources and the impacts at downwind receptors. Two frameworks of source apportionment models exist: source-oriented and receptor-oriented. Source based apportionment models use presumed emissions and atmospheric processes to estimate the downwind source contributions. Conversely, receptor based models leverage speciated concentration data from downwind receptors and apply statistical methods to predict source contributions. Integration of both source-oriented and receptor-oriented models could lead to a better understanding of the implications sources have on the environment and society. The research presented here investigated three different types of constraints applied to the Positive Matrix Factorization (PMF) receptor model within the framework of the Multilinear Engine (ME-2): element ratio constraints, spatial separation constraints, and chemical transport model (CTM) source attribution constraints. PM10-2.5 mass and trace element concentrations were measured in Winston-Salem, Chicago, and St. Paul at up to 60 sites per city during two different seasons in 2010. PMF was used to explore the underlying sources of variability. Information on previously reported PM10-2.5 tire and brake wear profiles were used to constrain these features in PMF by prior specification of selected species ratios. We also modified PMF to allow for combining the measurements from all three cities into a single model while preserving city-specific soil features. Relatively minor differences were observed between model predictions with and without the prior ratio constraints, increasing confidence in our ability to identify separate brake wear and tire wear features. Using separate data, source contributions to total fine particle carbon predicted by a CTM were incorporated into the PMF receptor model to form a receptor-oriented hybrid model. The level of influence of the CTM versus traditional PMF was
Matrix elements of the electromagnetic operator between kaon and pion states
Baum, I.; Lubicz, V.; Martinelli, G.; Orifici, L.; Simula, S.
2011-10-01
We compute the matrix elements of the electromagnetic operator sF{sub {mu}{nu}}{sigma}{sup {mu}{nu}}d between kaon and pion states, using lattice QCD with maximally twisted-mass fermions and two flavors of dynamical quarks (N{sub f}=2). The operator is renormalized nonperturbatively in the RI'/MOM scheme and our simulations cover pion masses as light as 270 MeV and three values of the lattice spacing from {approx_equal}0.07 up to {approx_equal}0.1 fm. At the physical point our result for the corresponding tensor form factor at zero-momentum transfer is f{sub T}{sup K{pi}}(0)=0.417(14{sub stat})(5{sub syst}), where the systematic error does not include the effect of quenching the strange and charm quarks. Our result differs significantly from the old quenched result f{sub T}{sup K{pi}}(0)=0.78(6) obtained by the SPQ{sub cd}R Collaboration with pion masses above 500 MeV. We investigate the source of this difference and conclude that it is mainly related to the chiral extrapolation. We also study the tensor charge of the pion and obtain the value f{sub T}{sup {pi}{pi}}(0)=0.195(8{sub stat})(6{sub syst}) in good agreement with, but more accurate than the result f{sub T}{sup {pi}{pi}}(0)=0.216(34) obtained by the QCDSF Collaboration using higher pion masses.
Trajectories of S-matrix poles in a new finite-range potential
Racz, A.; Salamon, P.; Vertse, T.
2011-09-15
The trajectories of S-matrix poles are calculated in the finite-range phenomenological potential introduced recently by Salamon and Vertse [Phys. Rev. C 77, 037302 (2008)] (SV). The potential is similar to a Woods-Saxon (WS) interaction, but it is exactly zero beyond a radius, without any cutoff. The trajectories of the resonance poles in this SV potential are compared to the corresponding trajectories in a cutoff WS potential for l>0. The dependence on the cutoff radius is demonstrated. The starting points of the trajectories turn out to be related to the average ranges of the two terms in the SV potential.
Land Application of Wastes: An Educational Program. Potentially Toxic Elements - Module 11.
ERIC Educational Resources Information Center
Clarkson, W. W.; And Others
Five elements are identified as being potentially hazardous in this module. These are boron, cadmium, copper, molybdenum, and nickel. The hazards to plants and animals posed by these elements are discussed in some detail. The sources of toxic elements in sewage and the factors that effect the uptake of toxic elements by sewage sludge are also…
NASA Astrophysics Data System (ADS)
Whiting, Daniel J.; Keaveney, James; Adams, Charles S.; Hughes, Ifan G.
2016-04-01
Applying large magnetic fields to gain access to the hyperfine Paschen-Back regime can isolate three-level systems in a hot alkali metal vapors, thereby simplifying usually complex atom-light interactions. We use this method to make the first direct measurement of the |<5 P ||e r ||5 D >| matrix element in 87Rb. An analytic model with only three levels accurately models the experimental electromagnetically induced transparency spectra and extracted Rabi frequencies are used to determine the dipole matrix element. We measure |<5 P3 /2||e r ||5 D5 /2>| =(2.290 ±0 .002stat±0 .04syst) e a0 , which is in excellent agreement with the theoretical calculations of Safronova, Williams, and Clark [Phys. Rev. A 69, 022509 (2004), 10.1103/PhysRevA.69.022509].
NASA Astrophysics Data System (ADS)
Li, Shenmin; Li, Guohui; Guo, Hua
2001-12-01
The recently proposed single Lanczos propagation method [J. Chem. Phys. 111, 9944 (1999); ibid. 114, 1467 (2001)] is extended to complex-symmetric Hamiltonians. It is shown that the complex-symmetric Lanczos algorithm possesses several useful numerical properties similar to those observed in real-symmetric cases, which enable one to compute multiple transition amplitudes with a single Lanczos propagation. The usefulness of the method is illustrated in calculating the S-matrix elements for the collinear H+H2 reaction.
Diagnosis potential of near infrared Mueller Matrix imaging for colonic adenocarcinoma
NASA Astrophysics Data System (ADS)
Wang, Jianfeng; Zheng, Wei; Lin, Kan; Huang, Zhiwei
2016-03-01
Mueller matrix imaging along with polar decomposition method was employed for the colonic adenocarcinoma detection by polarized light in the near-infrared spectral range (700-1100 nm). A high-speed (<5s) Muller matrix imaging system with dual-rotating waveplates was developed. 16 (4 by 4) full Mueller matrices of the colonic tissues (i.e., normal and caner) were acquired. Polar decomposition was further implemented on the 16 images to derive the diattentuation, depolarization, and the retardance images. The decomposed images showed clear margin between the normal and adenocarcinomaous colon tissue samples. The work shows the potential of near-infrared Mueller matrix imaging for the early diagnosis and detection of malignant lesions in the colon.
Analytical O (αs) corrections to the beam frame double-spin density matrix elements of e+e-→t t ¯
NASA Astrophysics Data System (ADS)
Kaldamäe, L.; Groote, S.; Körner, J. G.
2016-12-01
We provide analytical results for the O (αs) corrections to the double-spin density matrix elements in the reaction e+e-→t t ¯ . These concern the elements l l , l t , l n , t t , t n , and n n of the double-spin density matrix elements where l , t , n stand for longitudinal, transverse and normal orientations with respect to the beam frame spanned by the electron and the top quark momentum.
Energy levels and transition probability matrix elements of ruby for maser applications
NASA Technical Reports Server (NTRS)
Berwin, R. W.
1971-01-01
Program computes fine structure energy levels of ruby as a function of magnetic field. Included in program is matrix formulation, each row of which contains a magnetic field and four corresponding energy levels.
NASA Astrophysics Data System (ADS)
Sze, K. Y.
1992-07-01
This paper presents an investigation of using orthogonal constant and higher order stress modes in formulating efficient hybrid elements by equipping the primary idea of Bergan and Hanssen (1975). Two sample elements modified from Pian-Sumihara 5-beta plane and Pian-Tong 18-beta hexahedral assumed contravariant stress elements are derived. With the suggested admissible simplifications of the flexibility matrices incorporated into the two new elements, new plane and hexahedral elements requiring respectively no and a negligible amount of computing efforts for inverting the flexibility matrices are formed. All proposed elements are stable, invariant, contain no empirically determined factor and strictly pass the patch test. Popular benchmark problems are studied and the accuracy of the proposed elements is close to their parent models.
NASA Astrophysics Data System (ADS)
Zubkov, Mikhail; Stait-Gardner, Timothy; Price, William S.
2014-06-01
Precise NMR diffusion measurements require detailed knowledge of the cumulative dephasing effect caused by the numerous gradient pulses present in most NMR pulse sequences. This effect, which ultimately manifests itself as the diffusion-related NMR signal attenuation, is usually described by the b-value or the b-matrix in the case of multidirectional diffusion weighting, the latter being common in diffusion-weighted NMR imaging. Neglecting some of the gradient pulses introduces an error in the calculated diffusion coefficient reaching in some cases 100% of the expected value. Therefore, ensuring the b-matrix calculation includes all the known gradient pulses leads to significant error reduction. Calculation of the b-matrix for simple gradient waveforms is rather straightforward, yet it grows cumbersome when complexly shaped and/or numerous gradient pulses are introduced. Making three broad assumptions about the gradient pulse arrangement in a sequence results in an efficient framework for calculation of b-matrices as well providing some insight into optimal gradient pulse placement. The framework allows accounting for the diffusion-sensitising effect of complexly shaped gradient waveforms with modest computational time and power. This is achieved by using the b-matrix elements of the simple unmodified pulse sequence and minimising the integration of the complexly shaped gradient waveform in the modified sequence. Such re-evaluation of the b-matrix elements retains all the analytical relevance of the straightforward approach, yet at least halves the amount of symbolic integration required. The application of the framework is demonstrated with the evaluation of the expression describing the diffusion-sensitizing effect, caused by different bipolar gradient pulse modules.
Zubkov, Mikhail; Stait-Gardner, Timothy; Price, William S
2014-06-01
Precise NMR diffusion measurements require detailed knowledge of the cumulative dephasing effect caused by the numerous gradient pulses present in most NMR pulse sequences. This effect, which ultimately manifests itself as the diffusion-related NMR signal attenuation, is usually described by the b-value or the b-matrix in the case of multidirectional diffusion weighting, the latter being common in diffusion-weighted NMR imaging. Neglecting some of the gradient pulses introduces an error in the calculated diffusion coefficient reaching in some cases 100% of the expected value. Therefore, ensuring the b-matrix calculation includes all the known gradient pulses leads to significant error reduction. Calculation of the b-matrix for simple gradient waveforms is rather straightforward, yet it grows cumbersome when complexly shaped and/or numerous gradient pulses are introduced. Making three broad assumptions about the gradient pulse arrangement in a sequence results in an efficient framework for calculation of b-matrices as well providing some insight into optimal gradient pulse placement. The framework allows accounting for the diffusion-sensitising effect of complexly shaped gradient waveforms with modest computational time and power. This is achieved by using the b-matrix elements of the simple unmodified pulse sequence and minimising the integration of the complexly shaped gradient waveform in the modified sequence. Such re-evaluation of the b-matrix elements retains all the analytical relevance of the straightforward approach, yet at least halves the amount of symbolic integration required. The application of the framework is demonstrated with the evaluation of the expression describing the diffusion-sensitizing effect, caused by different bipolar gradient pulse modules.
Wadt, W.R.; Hay, P.J.
1985-01-01
A consistent set of ab initio effective core potentials (ECP) has been generated for the main group elements from Na to Bi using the procedure originally developed by Kahn. The ECP's are derived from all-electron numerical Hartree--Fock atomic wave functions and fit to analytical representations for use in molecular calculations. For Rb to Bi the ECP's are generated from the relativistic Hartree--Fock atomic wave functions of Cowan which incorporate the Darwin and mass--velocity terms. Energy-optimized valence basis sets of (3s3p) primitive Gaussians are presented for use with the ECP's. Comparisons between all-electron and valence-electron ECP calculations are presented for NaF, NaCl, Cl/sub 2/, Cl/sub 2//sup -/, Br/sub 2/, Br/sub 2//sup -/, and Xe/sub 2//sup +/. The results show that the average errors introduced by the ECP's are generally only a few percent.
The Conservation/Solution Element (STE) Method for Linear Potential Flow Problems
NASA Technical Reports Server (NTRS)
Adeyeye, John O.; Attia, Naguib F.; Jackson, Joy; Hunter, Timothy
1996-01-01
The potential equation is discretized on rectangular domains using the Conservation/Solution Element Method (STE) approach. Computational examples with a discussion of numerical experience gained are given.
Tellurium: an element with great biological potency and potential.
Ba, Lalla Aicha; Döring, Mandy; Jamier, Vincent; Jacob, Claus
2010-10-07
Tellurium has long appeared as a nearly 'forgotten' element in Biology, with most studies focusing on tellurite, tellurate and a handful of organic tellurides. During the last decade, several discoveries have fuelled a renewed interest in this element. Bioincorporation of telluromethionine provides a new approach to add heavy atoms to selected sites in proteins. Cadmium telluride (CdTe) nanoparticles are fluorescent and may be used as quantum dots in imaging and diagnosis. The antibiotic properties of tellurite, long known yet almost forgotten, have attracted renewed interest, especially since the biochemical mechanisms of tellurium cytotoxicity are beginning to emerge. The close chemical relationship between tellurium and sulfur also transcends into in vitro and in vivo situations and provides new impetus for the development of enzyme inhibitors and redox modulators, some of which may be of interest in the field of antibiotics and anticancer drug design.
Ju, J.W.; Tseng, K.H.
1995-12-31
Discrete numerical integration algorithm is employed to integrate rate equations in the effective elastoplastic model for particle reinforced ductile matrix composites based on probabilistic micromechanical formulations. In particular, the unconditionally stable implicit backward Euler integration algorithm is formulated for elastoplasticity of particle reinforced plastic matrix composites. In addition to the local integration algorithm, in nonlinear finite element methods for boundary value problems, tangent moduli are needed for the global Newton`s iterations. For this purpose, the continuum tangent operator based on the continuous rate equations is derived. In order to preserve the quadratic rate of convergence, the consistent tangent operator is constructed based on the proposed backward Euler integration algorithm. The elastoplastic model is further extended to accommodate the effect of viscosity in the matrix. The extension is based on the method of Duvaut-Lions viscoplasticity. The local integration algorithm and the consistent tangent operator are formulated for particle reinforced viscoplastic matrix composites. Numerical experiments are performed to assess the capability of the proposed integration algorithm and the convergence behavior of various tangent moduli.
Analytic structure of the multichannel Jost matrix for potentials with Coulombic tails
Rakityansky, S. A.; Elander, N.
2013-12-15
A quantum system is considered that can move in N two-body channels with the potentials that may include the Coulomb interaction. For this system, the Jost matrix is constructed in such a way that all its dependencies on the channel momenta and Sommerfeld parameters are factorized in the form of explicit analytic expressions. It is shown that the two remaining unknown matrices are single-valued analytic functions of the energy and therefore can be expanded in the Taylor series near an arbitrary point within the domain of their analyticity. It is derived a system of first-order differential equations whose solutions determine the expansion coefficients of these series. Alternatively, the unknown expansion coefficients can be used as fitting parameters for parametrizing experimental data similarly to the effective-range expansion. Such a parametrization has the advantage of preserving proper analytic structure of the Jost matrix and can be done not only near the threshold energies, but around any collision or even complex energy. As soon as the parameters are obtained, the Jost matrix (and therefore the S-matrix) is known analytically on all sheets of the Riemann surface, and thus enables one to locate possible resonances.
Overlap Dirac operator at nonzero chemical potential and random matrix theory.
Bloch, Jacques; Wettig, Tilo
2006-07-07
We show how to introduce a quark chemical potential in the overlap Dirac operator. The resulting operator satisfies a Ginsparg-Wilson relation and has exact zero modes. It is no longer gamma5 Hermitian, but its nonreal eigenvalues still occur in pairs. We compute the spectral density of the operator on the lattice and show that, for small eigenvalues, the data agree with analytical predictions of non-Hermitian chiral random matrix theory for both trivial and nontrivial topology. We also explain an observed change in the number of zero modes as a function of chemical potential.
NASA Technical Reports Server (NTRS)
Judson, Richard S.; Kouri, Donald J.; Neuhauser, Daniel; Baer, Michael
1990-01-01
An alternative time-dependent wave-packet method for treating three-dimensional gas phase reactive atom-diatom collisions is presented. The method employs a nonreactive body-frame wave packet propagation procedure, made possible by judicious use of absorbing optical potentials, a novel scheme for interpolating the wave function from coordinates in one arrangement to those in another and the fact that the time-dependent Schroedinger equation is an initial-value problem. The last feature makes possible a computationally viable and accurate procedure for changing from one arrangement's coordinates to another. In addition, the method allows the determination of S-matrix elements over a wide range of energies from a single wave-packet propagation. The method is illustrated by carrying out detailed calculations of inelastic and reactive scattering in the H + H2 system using the Liu-Siegbahn-Truhlar-Horowitz potential surface.
NASA Astrophysics Data System (ADS)
Xu, Peng
Containing no fertile materials, inert matrix fuel (IMF) has been introduced as a potential transmutation solution for the increasing inventory of both weapon grade and reactor grade plutonium (Pu). In the present work, the MgO-pyrochlore (Nd2Zr2O7) composites and spinel magnesium stannate (Mg2SnO4) were selected as potential inert matrix (IM) materials. A comprehensive investigation was conducted on evaluation of the engineering parameters of the potential IM materials. The MgO-Nd2Zr2O7 composites and Mg 2SnO4 were fabricated through conventional solid state processing. The crystal structure and microstructure of the synthesized composites and Mg2SnO4 were studied. The irradiation tolerance of the potential IM materials was first assessed. The resistance of Mg2SnO 4 against irradiation induced amorphization was assessed experimentally using in situ TEM technique. The critical amorphization doses for Mg2SnO4 irradiated by 1 MeV Kr2+ ions were determined to be 5.5 dpa at 50 K and 11.0 dpa at 150 K, respectively. The obtained results were compared with other spinels especially MgAl 2O4, and the radiation tolerance of spinels were discussed. The next evaluation was water corrosion resistance of the potential IM materials. Homogeneous MgO-Nd2Zr2O7 composites exhibited an improved hydrothermal corrosion resistance than inhomogeneous composites and pure MgO. Even though spinel Mg2SnO4 was not stable in water at 300°C and saturation pressure, the corrosion was limited only to the surface, and the volume and mass changes were less than 1 % after 720 h corrosion. Feasibility of aqueous reprocessing was evaluated by studying the dissolution behavior of the potential IM materials in acidic solutions, with an emphasis on nitric acid. Dissolution of the MgO-Nd2Zr2O 7 composites in HNO3 resulted in a selective dissolution of MgO. Mechanical agitation such as magnetic bar stirring was necessary to achieve a completed dissolution of MgO and disintegration of porous Nd 2Zr2O7
NASA Astrophysics Data System (ADS)
Wu, Yueqian; Yang, Minglin; Sheng, Xinqing; Ren, Kuan Fang
2015-05-01
Light scattering properties of absorbing particles, such as the mineral dusts, attract a wide attention due to its importance in geophysical and environment researches. Due to the absorbing effect, light scattering properties of particles with absorption differ from those without absorption. Simple shaped absorbing particles such as spheres and spheroids have been well studied with different methods but little work on large complex shaped particles has been reported. In this paper, the surface Integral Equation (SIE) with Multilevel Fast Multipole Algorithm (MLFMA) is applied to study scattering properties of large non-spherical absorbing particles. SIEs are carefully discretized with piecewise linear basis functions on triangle patches to model whole surface of the particle, hence computation resource needs increase much more slowly with the particle size parameter than the volume discretized methods. To improve further its capability, MLFMA is well parallelized with Message Passing Interface (MPI) on distributed memory computer platform. Without loss of generality, we choose the computation of scattering matrix elements of absorbing dust particles as an example. The comparison of the scattering matrix elements computed by our method and the discrete dipole approximation method (DDA) for an ellipsoid dust particle shows that the precision of our method is very good. The scattering matrix elements of large ellipsoid dusts with different aspect ratios and size parameters are computed. To show the capability of the presented algorithm for complex shaped particles, scattering by asymmetry Chebyshev particle with size parameter larger than 600 of complex refractive index m = 1.555 + 0.004 i and different orientations are studied.
Agodi, C. Calabretta, L.; Calanna, A.; Carbone, D.; Cavallaro, M.; Colonna, M.; Cuttone, G.; Finocchiaro, P.; Pandola, L.; Rifuggiato, D.; Tudisco, S.; Cappuzzello, F.; Greco, V.; Bonanno, D. L.; Bongiovanni, D. G.; Longhitano, F.; Branchina, V.; Foti, A.; Lo Presti, D.; Lanzalone, G.; and others
2015-10-28
In the NUMEN Project it is proposed an innovative technique to access the nuclear matrix elements entering in the expression of the life-time of the neutrinoless double beta decay, using relevant cross sections of double charge exchange reactions. A key aspect is the use of MAGNEX large acceptance magnetic spectrometer, for the detection of the ejectiles, and of the INFN Laboratori Nazionali del Sud (LNS) K800 Superconducting Cyclotron (CS), for the acceleration of the required high resolution and low emittance heavy-ion beams.
NASA Astrophysics Data System (ADS)
Chang, Jintao; He, Honghui; Wang, Ye; Huang, Yi; Li, Xianpeng; He, Chao; Liao, Ran; Zeng, Nan; Liu, Shaoxiong; Ma, Hui
2016-05-01
A polarization microscope is a useful tool to reveal the optical anisotropic nature of a specimen and can provide abundant microstructural information about samples. We present a division of focal plane (DoFP) polarimeter-based polarization microscope capable of simultaneously measuring both the Stokes vector and the 3×4 Mueller matrix with an optimal polarization illumination scheme. The Mueller matrix images of unstained human carcinoma tissue slices show that the m24 and m34 elements can provide important information for pathological observations. The characteristic features of the m24 and m34 elements can be enhanced by polarization staining under illumination by a circularly polarized light. Hence, combined with a graphics processing unit acceleration algorithm, the DoFP polarization microscope is capable of real-time polarization imaging for potential quick clinical diagnoses of both standard and frozen slices of human carcinoma tissues.
NASA Astrophysics Data System (ADS)
Kopp, Wassja A.; Leonhard, Kai
2016-12-01
We show how inverse metric tensors and rovibrational kinetic energy operators in terms of internal bond-angle coordinates can be obtained analytically following a factorization of the Jacobian worked out by Frederick and Woywod. The structure of these Jacobians is exploited in two ways: On one hand, the elements of the metric tensor as well as its determinant all have the form ∑rmsin (αn) cos (βo) . This form can be preserved by working with the adjugate metric tensor that can be obtained without divisions. On the other hand, the adjugate can be obtained with less effort by exploiting the lower triangular structure of the Jacobians. Together with a suitable choice of the wavefunction, we avoid singularities and show how to obtain analytical expressions for the rovibrational kinetic energy matrix elements.
Gao, Jun; Manard, Benjamin T; Castro, Alonso; Montoya, Dennis P; Xu, Ning; Chamberlin, Rebecca M
2017-05-15
Advances in sample nebulization and injection technology have significantly reduced the volume of solution required for trace impurity analysis in plutonium and uranium materials. Correspondingly, we have designed and tested a novel chip-based microfluidic platform, containing a 100-µL or 20-µL solid-phase microextraction column, packed by centrifugation, which supports nuclear material mass and solution volume reductions of 90% or more compared to standard methods. Quantitative recovery of 28 trace elements in uranium was demonstrated using a UTEVA chromatographic resin column, and trace element recovery from thorium (a surrogate for plutonium) was similarly demonstrated using anion exchange resin AG MP-1. Of nine materials tested, compatibility of polyvinyl chloride (PVC), polypropylene (PP), and polytetrafluoroethylene (PTFE) chips with the strong nitric acid media was highest. The microcolumns can be incorporated into a variety of devices and systems, and can be loaded with other solid-phase resins for trace element assay in high-purity metals.
A static analysis of metal matrix composite spur gear by three-dimensional finite element method
NASA Astrophysics Data System (ADS)
Ganesan, N.; Vijayarangan, S.
1993-03-01
A number of engineering components have recently been made using metal matrix composite (MMC) materials, due to their overwhelming advantages, such as light weight high strength, higher dimensional stability and minimal attack by environment, when compared with polymer-based composite materials, even though the cost of MMCs are very high. Power transmission gears are one such area able to make use of MMC materials. Here an attempt is made to study and compare the performance of gears made of MMC materials with that of conventional steel material gears. It may be concluded from this study that MMC materials are highly suitable for making gears that are to transmit even fairly large power.
Optical elements formed by compressed gases: Analysis and potential applications
NASA Technical Reports Server (NTRS)
Howes, W. L.
1986-01-01
Spherical, cylindrical, and conical shock waves are optically analogous to gas lenses. The geometrical optics of these shock configurations are analyzed as they pertain to flow visualization instruments, particularly the rainbow schlieren apparatus and single-pass interferometers. It is proposed that a lens or mirror formed by gas compressed between plastic sheets has potential as a fluid visualization test object; as the objective mirror in a very large space-based telescope, communication antenna, or energy collector; as the objective mirror in inexpensive commercial telescopes; and as a component in fluid visualization apparatuses.
Short-distance matrix elements for D-meson mixing for 2+1 flavor lattice QCD
NASA Astrophysics Data System (ADS)
Chang, Chia Cheng
We study the short-distance hadronic matrix elements for D-meson mixing with partially quenched Nf = 2+1 lattice QCD. We use a large set of the MIMD Lattice Computation Collaboration's gauge configurations with a2 tadpole-improved staggered sea quarks and tadpole-improved Luscher-Weisz gluons. We use the a2 tadpole-improved action for valence light quarks and the Sheikoleslami-Wohlert action with the Fermilab interpretation for the valence charm quark. Our calculation covers the complete set of five operators needed to constrain new physics models for D-meson mixing. We match our matrix elements to the MS-NDR scheme evaluated at 3GeV. We report values for the Beneke-Buchalla-Greub-Lenz-Nierste choice of evanescent operators and obtain
Bacteria Inside Semiconductors as Potential Sensor Elements: Biochip Progress
Sah, Vasu R.; Baier, Robert E.
2014-01-01
It was discovered at the beginning of this Century that living bacteria—and specifically the extremophile Pseudomonas syzgii—could be captured inside growing crystals of pure water-corroding semiconductors—specifically germanium—and thereby initiated pursuit of truly functional “biochip-based” biosensors. This observation was first made at the inside ultraviolet-illuminated walls of ultrapure water-flowing semiconductor fabrication facilities (fabs) and has since been, not as perfectly, replicated in simpler flow cell systems for chip manufacture, described here. Recognizing the potential importance of these adducts as optical switches, for example, or probes of metabolic events, the influences of the fabs and their components on the crystal nucleation and growth phenomena now identified are reviewed and discussed with regard to further research needs. For example, optical beams of current photonic circuits can be more easily modulated by integral embedded cells into electrical signals on semiconductors. Such research responds to a recently published Grand Challenge in ceramic science, designing and synthesizing oxide electronics, surfaces, interfaces and nanoscale structures that can be tuned by biological stimuli, to reveal phenomena not otherwise possible with conventional semiconductor electronics. This short review addresses only the fabrication facilities' features at the time of first production of these potential biochips. PMID:24961215
Bacteria inside semiconductors as potential sensor elements: biochip progress.
Sah, Vasu R; Baier, Robert E
2014-06-24
It was discovered at the beginning of this Century that living bacteria-and specifically the extremophile Pseudomonas syzgii-could be captured inside growing crystals of pure water-corroding semiconductors-specifically germanium-and thereby initiated pursuit of truly functional "biochip-based" biosensors. This observation was first made at the inside ultraviolet-illuminated walls of ultrapure water-flowing semiconductor fabrication facilities (fabs) and has since been, not as perfectly, replicated in simpler flow cell systems for chip manufacture, described here. Recognizing the potential importance of these adducts as optical switches, for example, or probes of metabolic events, the influences of the fabs and their components on the crystal nucleation and growth phenomena now identified are reviewed and discussed with regard to further research needs. For example, optical beams of current photonic circuits can be more easily modulated by integral embedded cells into electrical signals on semiconductors. Such research responds to a recently published Grand Challenge in ceramic science, designing and synthesizing oxide electronics, surfaces, interfaces and nanoscale structures that can be tuned by biological stimuli, to reveal phenomena not otherwise possible with conventional semiconductor electronics. This short review addresses only the fabrication facilities' features at the time of first production of these potential biochips.
Two distinct membrane potential-dependent steps drive mitochondrial matrix protein translocation.
Schendzielorz, Alexander Benjamin; Schulz, Christian; Lytovchenko, Oleksandr; Clancy, Anne; Guiard, Bernard; Ieva, Raffaele; van der Laan, Martin; Rehling, Peter
2017-01-02
Two driving forces energize precursor translocation across the inner mitochondrial membrane. Although the membrane potential (Δψ) is considered to drive translocation of positively charged presequences through the TIM23 complex (presequence translocase), the activity of the Hsp70-powered import motor is crucial for the translocation of the mature protein portion into the matrix. In this study, we show that mitochondrial matrix proteins display surprisingly different dependencies on the Δψ. However, a precursor's hypersensitivity to a reduction of the Δψ is not linked to the respective presequence, but rather to the mature portion of the polypeptide chain. The presequence translocase constituent Pam17 is specifically recruited by the receptor Tim50 to promote the transport of hypersensitive precursors into the matrix. Our analyses show that two distinct Δψ-driven translocation steps energize precursor passage across the inner mitochondrial membrane. The Δψ- and Pam17-dependent import step identified in this study is positioned between the two known energy-dependent steps: Δψ-driven presequence translocation and adenosine triphosphate-driven import motor activity.
[Matrix Gla protein as natural inhibitor of vascular calcification and potential treatment target].
Mayer, Otto
2016-01-01
Vascular calcification was once regarded as an advanced stage of atherosclerosis only. However, calcification is currently considered as highly regulated and potentially reversible process.Matrix Gla protein (MGP) represents natural inhibitor of vascular calcification, whereas vitamin K is key co-factor of its maturation to the active form. There is accumulating evidence that vitamin K status and corresponding MGP activity may influence cardiovascular risk. This review summarizes pathophysiological mechanism and recent evidence relative to MGP. Moreover, available data concerning vitamin K supplementation are depicted.
R-matrix and Potential Model Extrapolations for NACRE Update and Extension Project
Aikawa, Masayuki; Katsuma, Masahiko; Takahashi, Kohji; Arnould, Marcel; Arai, Koji; Utsunomiya, Hiroaki
2006-07-12
NACRE, the 'nuclear astrophysics compilation of reaction rates', has been widely utilized in stellar evolution and nucleosynthesis studies. Its update and extension programme started within a Konan-Universite Libre de Bruxelles (ULB) collaboration. At the present moment, experimental data in refereed journals have been collected, and their theoretical extrapolations are being performed using the R-matrix or potential models. For the 3H(d,n)4He and 2H(p,{gamma})3He reactions, we present preliminary results that could well reproduce the experimental data.
Cao, Li; Guilak, Farshid; Setton, Lori A.
2009-01-01
Anulus fibrosus (AF) cells have been demonstrated to exhibit dramatic differences in morphology and biologic responses to different types of mechanical stimuli. AF cells may reside as single cell, paired or multiple cells in a contiguous pericellular matrix (PCM), whose structure and properties are expected to have a significant influence on the mechanical stimuli that these cells may experience during physiologic loading of the spine, as well as in tissue degeneration and regeneration. In this study, a computational model was developed to predict the micromechanical stimuli, such as stress and strain, fluid pressure and flow, of cells and their surrounding PCM in the AF tissue using three-dimensional (3D) finite element models based on in situ morphology. 3D solid geometries of cell-PCM regions were registered from serial confocal images obtained from mature rat AF tissues by custom codes. Distinct cell-matrix units were modeled with a custom 3D biphasic finite element code (COMSOL Multiphysics), and simulated to experience uni-axial tensile strain along the local collagen fiber direction. AF cells were predicted to experience higher volumetric strain with a strain amplification ratio (relative to that in the extracellular matrix) of ~ 3.1 – 3.8 at equilibrium, as compared to the PCM domains (1.3 – 1.9). The strain concentrations were generally found at the cell/PCM interface and stress concentration at the PCM/ECM interface. Increased numbers of cells within a contiguous PCM was associated with an apparent increase of strain levels and decreased rate of fluid pressurization in the cell, with magnitudes dependent on the cell size, shape and relative position inside the PCM. These studies provide spatio-temporal information on micromechanics of AF cells in understanding the mechanotransduction in the intervertebral disc. PMID:19946619
Cwik, T.; Katz, D.S.
1996-12-31
Finite element modeling has proven useful for accurately simulating scattered or radiated electromagnetic fields from complex three-dimensional objects whose geometry varies on the scale of a fraction of an electrical wavelength. An unstructured finite element model of realistic objects leads to a large, sparse, system of equations that needs to be solved efficiently with regard to machine memory and execution time. Both factorization and iterative solvers can be used to produce solutions to these systems of equations. Factorization leads to high memory requirements that limit the electrical problem size of three-dimensional objects that can be modeled. An iterative solver can be used to efficiently solve the system without excessive memory use and in a minimal amount of time if the convergence rate is controlled.
Gao, Jun; Manard, Benjamin Thomas; Castro, Alonso; ...
2017-02-02
Advances in sample nebulization and injection technology have significantly reduced the volume of solution required for trace impurity analysis in plutonium and uranium materials. Correspondingly, we have designed and tested a novel chip-based microfluidic platform, containing a 100-µL or 20-µL solid-phase microextraction column, packed by centrifugation, which supports nuclear material mass and solution volume reductions of 90% or more compared to standard methods. Quantitative recovery of 28 trace elements in uranium was demonstrated using a UTEVA chromatographic resin column, and trace element recovery from thorium (a surrogate for plutonium) was similarly demonstrated using anion exchange resin AG MP-1. Of ninemore » materials tested, compatibility of polyvinyl chloride (PVC), polypropylene (PP), and polytetrafluoroethylene (PTFE) chips with the strong nitric acid media was highest. Finally, the microcolumns can be incorporated into a variety of devices and systems, and can be loaded with other solid-phase resins for trace element assay in high-purity metals.« less
NASA Technical Reports Server (NTRS)
Haque, A.; Ahmed, L.; Ware, T.; Jeelani, S.; Verrilli, Michael J. (Technical Monitor)
2001-01-01
The stress concentrations associated with circular notches and subjected to uniform tensile loading in woven ceramic matrix composites (CMCs) have been investigated for high-efficient turbine engine applications. The CMC's were composed of Nicalon silicon carbide woven fabric in SiNC matrix manufactured through polymer impregnation process (PIP). Several combinations of hole diameter/plate width ratios and ply orientations were considered in this study. In the first part, the stress concentrations were calculated measuring strain distributions surrounding the hole using strain gages at different locations of the specimens during the initial portion of the stress-strain curve before any microdamage developed. The stress concentration was also calculated analytically using Lekhnitskii's solution for orthotropic plates. A finite-width correction factor for anisotropic and orthotropic composite plate was considered. The stress distributions surrounding the circular hole of a CMC's plate were further studied using finite element analysis. Both solid and shell elements were considered. The experimental results were compared with both the analytical and finite element solutions. Extensive optical and scanning electron microscopic examinations were carried out for identifying the fracture behavior and failure mechanisms of both the notched and notched specimens. The stress concentration factors (SCF) determined by analytical method overpredicted the experimental results. But the numerical solution underpredicted the experimental SCF. Stress concentration factors are shown to increase with enlarged hole size and the effects of ply orientations on stress concentration factors are observed to be negligible. In all the cases, the crack initiated at the notch edge and propagated along the width towards the edge of the specimens.
Li, Zhendong; Suo, Bingbing; Liu, Wenjian
2014-12-28
The recently proposed rigorous yet abstract theory of first order nonadiabatic coupling matrix elements (fo-NACME) between electronically excited states [Z. Li and W. Liu, J. Chem. Phys. 141, 014110 (2014)] is specified in detail for two widely used models: The time-dependent density functional theory and the particle-particle Tamm-Dancoff approximation. The actual implementation employs a Lagrangian formalism with atomic-orbital based direct algorithms, which makes the computation of fo-NACME very similar to that of excited-state gradients. Although the methods have great potential in investigating internal conversions and nonadiabatic dynamics between excited states of large molecules, only prototypical systems as a first pilot application are considered here to illustrate some conceptual aspects.
NASA Astrophysics Data System (ADS)
Li, Zhendong; Suo, Bingbing; Liu, Wenjian
2014-12-01
The recently proposed rigorous yet abstract theory of first order nonadiabatic coupling matrix elements (fo-NACME) between electronically excited states [Z. Li and W. Liu, J. Chem. Phys. 141, 014110 (2014)] is specified in detail for two widely used models: The time-dependent density functional theory and the particle-particle Tamm-Dancoff approximation. The actual implementation employs a Lagrangian formalism with atomic-orbital based direct algorithms, which makes the computation of fo-NACME very similar to that of excited-state gradients. Although the methods have great potential in investigating internal conversions and nonadiabatic dynamics between excited states of large molecules, only prototypical systems as a first pilot application are considered here to illustrate some conceptual aspects.
Li, Zhendong; Suo, Bingbing; Liu, Wenjian
2014-12-28
The recently proposed rigorous yet abstract theory of first order nonadiabatic coupling matrix elements (fo-NACME) between electronically excited states [Z. Li and W. Liu, J. Chem. Phys. 141, 014110 (2014)] is specified in detail for two widely used models: The time-dependent density functional theory and the particle-particle Tamm-Dancoff approximation. The actual implementation employs a Lagrangian formalism with atomic-orbital based direct algorithms, which makes the computation of fo-NACME very similar to that of excited-state gradients. Although the methods have great potential in investigating internal conversions and nonadiabatic dynamics between excited states of large molecules, only prototypical systems as a first pilot application are considered here to illustrate some conceptual aspects.
NASA Astrophysics Data System (ADS)
Weeks, David E.; Niday, Thomas A.; Yang, Sang H.
2006-10-01
Inelastic scattering matrix elements for the nonadiabatic collision B(P1/22)+H2(Σg+1,j)↔B(P3/22)+H2(Σg+1,j') are calculated using the time dependent channel packet method (CPM). The calculation employs 1A'2, 2A'2, and 1A″2 adiabatic electronic potential energy surfaces determined by numerical computation at the multireference configuration-interaction level [M. H. Alexander, J. Chem. Phys. 99, 6041 (1993)]. The 1A'2 and 2A'2, adiabatic electronic potential energy surfaces are transformed to yield diabatic electronic potential energy surfaces that, when combined with the total B +H2 rotational kinetic energy, yield a set of effective potential energy surfaces [M. H. Alexander et al., J. Chem. Phys. 103, 7956 (1995)]. Within the framework of the CPM, the number of effective potential energy surfaces used for the scattering matrix calculation is then determined by the size of the angular momentum basis used as a representation. Twenty basis vectors are employed for these calculations, and the corresponding effective potential energy surfaces are identified in the asymptotic limit by the H2 rotor quantum numbers j =0, 2, 4, 6 and B electronic states Pja2, ja=1/2, 3/2. Scattering matrix elements are obtained from the Fourier transform of the correlation function between channel packets evolving in time on these effective potential energy surfaces. For these calculations the H2 bond length is constrained to a constant value of req=1.402a.u. and state to state scattering matrix elements corresponding to a total angular momentum of J =1/2 are discussed for j =0↔j'=0,2,4 and P1/22↔P1/22, P3/22 over a range of total energy between 0.0 and 0.01a.u.
Weeks, David E; Niday, Thomas A; Yang, Sang H
2006-10-28
Inelastic scattering matrix elements for the nonadiabatic collision B(2P1/2)+H2(1Sigmag+,j)<-->B(2P3/2)+H2(1Sigmag+,j') are calculated using the time dependent channel packet method (CPM). The calculation employs 1 2A', 2 2A', and 1 2A" adiabatic electronic potential energy surfaces determined by numerical computation at the multireference configuration-interaction level [M. H. Alexander, J. Chem. Phys. 99, 6041 (1993)]. The 1 2A' and 2 2A', adiabatic electronic potential energy surfaces are transformed to yield diabatic electronic potential energy surfaces that, when combined with the total B+H2 rotational kinetic energy, yield a set of effective potential energy surfaces [M. H. Alexander et al., J. Chem. Phys. 103, 7956 (1995)]. Within the framework of the CPM, the number of effective potential energy surfaces used for the scattering matrix calculation is then determined by the size of the angular momentum basis used as a representation. Twenty basis vectors are employed for these calculations, and the corresponding effective potential energy surfaces are identified in the asymptotic limit by the H2 rotor quantum numbers j=0, 2, 4, 6 and B electronic states 2Pja, ja=1/2, 3/2. Scattering matrix elements are obtained from the Fourier transform of the correlation function between channel packets evolving in time on these effective potential energy surfaces. For these calculations the H2 bond length is constrained to a constant value of req=1.402 a.u. and state to state scattering matrix elements corresponding to a total angular momentum of J=1/2 are discussed for j=0<-->j'=0,2,4 and 2P1/2<-->2P1/2, 2P3/2 over a range of total energy between 0.0 and 0.01 a.u.
NASA Astrophysics Data System (ADS)
Saxe, Paul; Yarkony, David R.
1987-01-01
A recently proposed methodology for determining second derivative nonadiabatic coupling matrix elements h(J,I,Rα,R) ≡<ΨJ(r;R)‖(∂2/∂R2α )ΨI(r;R)>r based on analytic gradient methods is implemented and discussed. Here r denotes the electronic coordinates, R the nuclear coordinates, and the ΨJ (r;R) are eigenfunctions of the nonrelativistic Born-Oppenheimer Hamiltonian at the state averaged MCSCF/CI level. The region of a conical intersection of the 1,2 2A' potential energy surfaces of the Li-H2 system is considered in order to illustrate the potential of this approach. The relation between h(J,I,Rα,R) and the first derivative matrix elements g(J,I,Rα,R) ≡<ΨJ(r;R)‖(∂/∂Rα)ΨI (r;R)>r is considered and the role of symmetry discussed. The h(J,I,Rα,R) are analyzed in terms of contributions from molecular orbital and CI coefficient derivatives and the importance of the various nuclear degree of freedom, Rα, is considered. It is concluded that for the case considered a flexible multiconfiguration wave function is desirable for characterizing h(J,I,Rα,R). This methodology complements recent advances in treating nonadiabatic processes for diatomic and triatomic systems starting with adiabatic states, including the work of Mead, Truhlar, and co-workers on conical (Jahn-Teller) intersections in X3 systems, by providing an essential computational step for the ab initio characterization the relevant electronic structure parameters.
Singular-potential random-matrix model arising in mean-field glassy systems.
Akemann, Gernot; Villamaina, Dario; Vivo, Pierpaolo
2014-06-01
We consider an invariant random matrix ensemble where the standard Gaussian potential is distorted by an additional single pole of arbitrary fixed order. Potentials with first- and second-order poles have been considered previously and found applications in quantum chaos and number theory. Here we present an application to mean-field glassy systems. We derive and solve the loop equation in the planar limit for the corresponding class of potentials. We find that the resulting mean or macroscopic spectral density is generally supported on two disconnected intervals lying on the two sides of the repulsive pole, whose edge points can be completely determined imposing the additional constraint of traceless matrices on average. For an unbounded potential with an attractive pole, we also find a possible one-cut solution for certain values of the couplings, which is ruled out when the traceless condition is imposed. Motivated by the calculation of the distribution of the spin-glass susceptibility in the Sherrington-Kirkpatrick spin-glass model, we consider in detail a second-order pole for a zero-trace model and provide the most explicit solution in this case. In the limit of a vanishing pole, we recover the standard semicircle. Working in the planar limit, our results apply to matrices with orthogonal, unitary, and symplectic invariance. Numerical simulations and an independent analytical Coulomb fluid calculation for symmetric potentials provide an excellent confirmation of our results.
Singular-potential random-matrix model arising in mean-field glassy systems
NASA Astrophysics Data System (ADS)
Akemann, Gernot; Villamaina, Dario; Vivo, Pierpaolo
2014-06-01
We consider an invariant random matrix ensemble where the standard Gaussian potential is distorted by an additional single pole of arbitrary fixed order. Potentials with first- and second-order poles have been considered previously and found applications in quantum chaos and number theory. Here we present an application to mean-field glassy systems. We derive and solve the loop equation in the planar limit for the corresponding class of potentials. We find that the resulting mean or macroscopic spectral density is generally supported on two disconnected intervals lying on the two sides of the repulsive pole, whose edge points can be completely determined imposing the additional constraint of traceless matrices on average. For an unbounded potential with an attractive pole, we also find a possible one-cut solution for certain values of the couplings, which is ruled out when the traceless condition is imposed. Motivated by the calculation of the distribution of the spin-glass susceptibility in the Sherrington-Kirkpatrick spin-glass model, we consider in detail a second-order pole for a zero-trace model and provide the most explicit solution in this case. In the limit of a vanishing pole, we recover the standard semicircle. Working in the planar limit, our results apply to matrices with orthogonal, unitary, and symplectic invariance. Numerical simulations and an independent analytical Coulomb fluid calculation for symmetric potentials provide an excellent confirmation of our results.
Ionization potentials of superheavy elements No, Lr, and Rf and their ions
Dzuba, V. A.; Safronova, M. S.; Safronova, U. I.; Kramida, A.
2016-01-01
We predict ionization potentials of superheavy elements No, Lr, and Rf and their ions using a relativistic hybrid method that combines configuration interaction (CI) with the linearized coupled-cluster approach. Extensive study of the completeness of the four-electron CI calculations for Hf and Rf was carried out. As a test of theoretical accuracy, we also calculated ionization potential of Yb, Lu, Hf, and their ions, which are homologues of the superheavy elements of this study. PMID:28058290
Ionization potentials of superheavy elements No, Lr, and Rf and their ions
NASA Astrophysics Data System (ADS)
Dzuba, V. A.; Safronova, M. S.; Safronova, U. I.; Kramida, A.
2016-10-01
We predict ionization potentials of superheavy elements No, Lr, and Rf and their ions using a relativistic hybrid method that combines configuration interaction (CI) with the linearized coupled-cluster approach. Extensive study of the completeness of the four-electron CI calculations for Hf and Rf was carried out. As a test of theoretical accuracy, we also calculated ionization potential of Yb, Lu, Hf, and their ions, which are homologues of the superheavy elements of this study.
NASA Astrophysics Data System (ADS)
Spiegel, J. Dominik; Lyskov, Igor; Kleinschmidt, Martin; Marian, Christel M.
2017-01-01
BODIPY-based dyads serve as model systems for the investigation of excitation energy transfer (EET). Through-space EET is brought about by direct and exchange interactions between the transition densities of donor and acceptor localized states. The presence of a molecular linker gives rise to additional charge transfer (CT) contributions. Here, we present a novel approach for the calculation of the excitonic coupling matrix element (ECME) including CT contributions which is based on supermolecular one-electron transition density matrices (STD). The validity of the approach is assessed for a model system of two π -stacked ethylene molecules at varying intermolecular separation. Wave functions and electronic excitation energies of five EET cassettes comprising anthracene as exciton donor and BODIPY as exciton acceptor are obtained by the redesigned combined density functional theory and multireference configuration interaction (DFT/MRCI-R) method. CT contributions to the ECME are shown to be important in the covalently linked EET cassettes.
NASA Astrophysics Data System (ADS)
Al Saleh, Salwa
2016-10-01
This paper completes a previous published work that calculated analytically the relativistic wavefunctions for bound electron in a Compton diffusion process. This work calculates the relativistic propagator and the Wronskian of the two associated Feynman diagrams of Compton diffusion (emission first and absorption first). Then find an explicit expression for the covariant matrix elements separated into two parts: spin-angular part and radial part. Using these explicit expressions, the effective cross-section for Compton diffusion in the most general form is obtained in terms of basic dynamical and static quantities, like electron's and photon's 4-momenta and atomic number. The form of the cross-section is put ready for numerical calculations.
Measurement of the Cabibbo-Kobayashi-Maskawa Matrix Element |Vub| with B→ρeν Decays
NASA Astrophysics Data System (ADS)
Aubert, B.; Barate, R.; Boutigny, D.; Gaillard, J.-M.; Hicheur, A.; Karyotakis, Y.; Lees, J. P.; Robbe, P.; Tisserand, V.; Zghiche, A.; Palano, A.; Pompili, A.; Chen, J. C.; Qi, N. D.; Rong, G.; Wang, P.; Zhu, Y. S.; Eigen, G.; Ofte, I.; Stugu, B.; Abrams, G. S.; Borgland, A. W.; Breon, A. B.; Brown, D. N.; Button-Shafer, J.; Cahn, R. N.; Charles, E.; Gill, M. S.; Gritsan, A. V.; Groysman, Y.; Jacobsen, R. G.; Kadel, R. W.; Kadyk, J.; Kerth, L. T.; Kolomensky, Yu. G.; Kral, J. F.; Leclerc, C.; Levi, M. E.; Lynch, G.; Mir, L. M.; Oddone, P. J.; Orimoto, T. J.; Pripstein, M.; Roe, N. A.; Romosan, A.; Ronan, M. T.; Shelkov, V. G.; Telnov, A. V.; Wenzel, W. A.; Harrison, T. J.; Hawkes, C. M.; Knowles, D. J.; O'Neale, S. W.; Penny, R. C.; Watson, A. T.; Watson, N. K.; Deppermann, T.; Goetzen, K.; Koch, H.; Lewandowski, B.; Pelizaeus, M.; Peters, K.; Schmuecker, H.; Steinke, M.; Barlow, N. R.; Bhimji, W.; Boyd, J. T.; Chevalier, N.; Clark, P. J.; Cottingham, W. N.; Mackay, C.; Wilson, F. F.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Thiessen, D.; Jolly, S.; Kyberd, P.; McKemey, A. K.; Blinov, V. E.; Bukin, A. D.; Buzykaev, A. R.; Golubev, V. B.; Ivanchenko, V. N.; Korol, A. A.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Yushkov, A. N.; Best, D.; Chao, M.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; McMahon, S.; Mommsen, R. K.; Stoker, D. P.; Buchanan, C.; Hadavand, H. K.; Hill, E. J.; Macfarlane, D. B.; Paar, H. P.; Rahatlou, Sh.; Raven, G.; Schwanke, U.; Sharma, V.; Berryhill, J. W.; Campagnari, C.; Dahmes, B.; Kuznetsova, N.; Levy, S. L.; Long, O.; Lu, A.; Mazur, M. A.; Richman, J. D.; Verkerke, W.; Beringer, J.; Eisner, A. M.; Grothe, M.; Heusch, C. A.; Lockman, W. S.; Pulliam, T.; Schalk, T.; Schmitz, R. E.; Schumm, B. A.; Seiden, A.; Turri, M.; Walkowiak, W.; Williams, D. C.; Wilson, M. G.; Albert, J.; Chen, E.; Dubois-Felsmann, G. P.; Dvoretskii, A.; Hitlin, D. G.; Narsky, I.; Porter, F. C.; Ryd, A.; Samuel, A.; Yang, S.; Jayatilleke, S.; Mancinelli, G.; Meadows, B. T.; Sokoloff, M. D.; Barillari, T.; Blanc, F.; Bloom, P.; Ford, W. T.; Nauenberg, U.; Olivas, A.; Rankin, P.; Roy, J.; Smith, J. G.; van Hoek, W. C.; Zhang, L.; Harton, J. L.; Hu, T.; Soffer, A.; Toki, W. H.; Wilson, R. J.; Zhang, J.; Altenburg, D.; Brandt, T.; Brose, J.; Colberg, T.; Dickopp, M.; Dubitzky, R. S.; Hauke, A.; Lacker, H. M.; Maly, E.; Müller-Pfefferkorn, R.; Nogowski, R.; Otto, S.; Schubert, K. R.; Schwierz, R.; Spaan, B.; Wilden, L.; Bernard, D.; Bonneaud, G. R.; Brochard, F.; Cohen-Tanugi, J.; T'jampens, S.; Thiebaux, Ch.; Vasileiadis, G.; Verderi, M.; Anjomshoaa, A.; Bernet, R.; Khan, A.; Lavin, D.; Muheim, F.; Playfer, S.; Swain, J. E.; Tinslay, J.; Falbo, M.; Borean, C.; Bozzi, C.; Piemontese, L.; Sarti, A.; Treadwell, E.; Anulli, F.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Falciai, D.; Finocchiaro, G.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Zallo, A.; Bagnasco, S.; Buzzo, A.; Contri, R.; Crosetti, G.; Lo Vetere, M.; Macri, M.; Monge, M. R.; Passaggio, S.; Pastore, F. C.; Patrignani, C.; Robutti, E.; Santroni, A.; Tosi, S.; Bailey, S.; Morii, M.; Grenier, G. J.; Mallik, U.; Cochran, J.; Crawley, H. B.; Lamsa, J.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Yi, J.; Davier, M.; Grosdidier, G.; Höcker, A.; Laplace, S.; Le Diberder, F.; Lepeltier, V.; Lutz, A. M.; Petersen, T. C.; Plaszczynski, S.; Schune, M. H.; Tantot, L.; Wormser, G.; Bionta, R. M.; Brigljević, V.; Lange, D. J.; van Bibber, K.; Wright, D. M.; Bevan, A. J.; Fry, J. R.; Gabathuler, E.; Gamet, R.; George, M.; Kay, M.; Payne, D. J.; Sloane, R. J.; Touramanis, C.; Aspinwall, M. L.; Bowerman, D. A.; Dauncey, P. D.; Egede, U.; Eschrich, I.; Morton, G. W.; Nash, J. A.; Sanders, P.; Taylor, G. P.; Back, J. J.; Bellodi, G.; Dixon, P.; Harrison, P. F.; Shorthouse, H. W.; Strother, P.; Vidal, P. B.; Cowan, G.; Flaecher, H. U.; George, S.; Green, M. G.; Kurup, A.; Marker, C. E.; McMahon, T. R.; Ricciardi, S.; Salvatore, F.; Vaitsas, G.; Winter, M. A.; Brown, D.; Davis, C. L.; Allison, J.; Barlow, R. J.; Forti, A. C.; Hart, P. A.; Jackson, F.; Lafferty, G. D.; Lyon, A. J.; Savvas, N.; Weatherall, J. H.; Williams, J. C.; Farbin, A.; Jawahery, A.; Lillard, V.; Roberts, D. A.; Blaylock, G.; Dallapiccola, C.; Flood, K. T.; Hertzbach, S. S.; Kofler, R.; Koptchev, V. B.; Moore, T. B.; Staengle, H.; Willocq, S.; Cowan, R.; Sciolla, G.; Taylor, F.; Yamamoto, R. K.; Milek, M.; Patel, P. M.; Palombo, F.; Bauer, J. M.; Cremaldi, L.; Eschenburg, V.; Kroeger, R.; Reidy, J.; Sanders, D. A.; Summers, D. J.; Zhao, H.; Hast, C.; Taras, P.; Nicholson, H.; Cartaro, C.; Cavallo, N.; de Nardo, G.; Fabozzi, F.; Gatto, C.; Lista, L.; Paolucci, P.; Piccolo, D.; Sciacca, C.; Losecco, J. M.; Alsmiller, J. R.; Gabriel, T. A.; Brau, B.; Brau, J.; Frey, R.; Iwasaki, M.; Potter, C. T.; Sinev, N. B.; Strom, D.; Torrence, E.; Colecchia, F.; Dorigo, A.; Galeazzi, F.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Tiozzo, G.; Voci, C.; Benayoun, M.; Briand, H.; Chauveau, J.; David, P.; de La Vaissière, Ch.; del Buono, L.; Hamon, O.; Leruste, Ph.; Ocariz, J.; Pivk, M.; Roos, L.; Stark, J.; Manfredi, P. F.; Re, V.; Speziali, V.; Gladney, L.; Guo, Q. H.; Panetta, J.; Angelini, C.; Batignani, G.; Bettarini, S.; Bondioli, M.; Bucci, F.; Calderini, G.; Campagna, E.; Carpinelli, M.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Marchiori, G.; Martinez-Vidal, F.; Morganti, M.; Neri, N.; Paoloni, E.; Rama, M.; Rizzo, G.; Sandrelli, F.; Triggiani, G.; Walsh, J.; Haire, M.; Judd, D.; Paick, K.; Turnbull, L.; Wagoner, D. E.; Danielson, N.; Elmer, P.; Lu, C.; Miftakov, V.; Olsen, J.; Smith, A. J.; Tumanov, A.; Varnes, E. W.; Bellini, F.; Cavoto, G.; del Re, D.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Leonardi, E.; Mazzoni, M. A.; Morganti, S.; Piredda, G.; Tehrani, F. Safai; Serra, M.; Voena, C.; Christ, S.; Wagner, G.; Waldi, R.; Adye, T.; de Groot, N.; Franek, B.; Geddes, N. I.; Gopal, G. P.; Olaiya, E. O.; Xella, S. M.; Aleksan, R.; Emery, S.; Gaidot, A.; Giraud, P.-F.; Hamel de Monchenault, G.; Kozanecki, W.; Langer, M.; London, G. W.; Mayer, B.; Schott, G.; Serfass, B.; Vasseur, G.; Yeche, Ch.; Zito, M.; Purohit, M. V.; Weidemann, A. W.; Yumiceva, F. X.; Abe, K.; Aston, D.; Bartoldus, R.; Berger, N.; Boyarski, A. M.; Buchmueller, O. L.; Convery, M. R.; Coupal, D. P.; Dong, D.; Dorfan, J.; Dunwoodie, W.; Field, R. C.; Glanzman, T.; Gowdy, S. J.; Grauges-Pous, E.; Hadig, T.; Halyo, V.; Himel, T.; Hryn'ova, T.; Huffer, M. E.; Innes, W. R.; Jessop, C. P.; Kelsey, M. H.; Kim, P.; Kocian, M. L.; Langenegger, U.; Leith, D. W.; Luitz, S.; Luth, V.; Lynch, H. L.; Marsiske, H.; Menke, S.; Messner, R.; Muller, D. R.; O'Grady, C. P.; Ozcan, V. E.; Perazzo, A.; Perl, M.; Petrak, S.; Ratcliff, B. N.; Robertson, S. H.; Roodman, A.; Salnikov, A. A.; Schietinger, T.; Schindler, R. H.; Schwiening, J.; Simi, G.; Snyder, A.; Soha, A.; Stelzer, J.; Su, D.; Sullivan, M. K.; Tanaka, H. A.; Va'Vra, J.; Wagner, S. R.; Weaver, M.; Weinstein, A. J.; Wisniewski, W. J.; Wright, D. H.; Young, C. C.; Burchat, P. R.; Cheng, C. H.; Meyer, T. I.; Roat, C.; Bugg, W.; Krishnamurthy, M.; Spanier, S. M.; Izen, J. M.; Kitayama, I.; Lou, X. C.; Bianchi, F.; Bona, M.; Gamba, D.; Bosisio, L.; della Ricca, G.; Dittongo, S.; Lanceri, L.; Poropat, P.; Vitale, L.; Vuagnin, G.; Henderson, R.; Panvini, R. S.; Banerjee, Sw.; Brown, C. M.; Fortin, D.; Jackson, P. D.; Kowalewski, R.; Roney, J. M.; Band, H. R.; Dasu, S.; Datta, M.; Eichenbaum, A. M.; Hu, H.; Johnson, J. R.; Liu, R.; di Lodovico, F.; Mohapatra, A. K.; Pan, Y.; Prepost, R.; Sekula, S. J.; von Wimmersperg-Toeller, J. H.; Wu, J.; Wu, S. L.; Yu, Z.; Neal, H.
2003-05-01
We present a measurement of the branching fraction for the rare decays B→ρeν and extract a value for the magnitude of Vub, one of the smallest elements of the Cabibbo-Kobayashi-Maskawa quark-mixing matrix. The results are given for five different calculations of form factors used to parametrize the hadronic current in semileptonic decays. Using a sample of 55×106 BB¯ meson pairs recorded with the BABAR detector at the PEP-II e+e- storage ring, we obtain B(B0→ρ-e+ν)=(3.29±0.42±0.47±0.55)×10-4 and |Vub|=(3.64±0.22±0.25+0.39-0.56)×10-3, where the uncertainties are statistical, systematic, and theoretical, respectively.
Aaltonen, T; González, B Alvarez; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Apresyan, A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Auerbach, B; Aurisano, A; Azfar, F; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauce, M; Bauer, G; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Bland, K R; Blumenfeld, B; Bocci, A; Bodek, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Brisuda, A; Bromberg, C; Brucken, E; Bucciantonio, M; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Calancha, C; Camarda, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Compostella, G; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Crescioli, F; Almenar, C Cuenca; Cuevas, J; Culbertson, R; Dagenhart, D; d'Ascenzo, N; Datta, M; de Barbaro, P; De Cecco, S; De Lorenzo, G; Dell'Orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Devoto, F; d'Errico, M; Di Canto, A; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Dorigo, T; Ebina, K; Elagin, A; Eppig, A; Erbacher, R; Errede, D; Errede, S; Ershaidat, N; Eusebi, R; Fang, H C; Farrington, S; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garfinkel, A F; Garosi, P; Gerberich, H; Gerchtein, E; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Ginsburg, C M; Giokaris, N; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldin, D; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; da Costa, J Guimaraes; Gunay-Unalan, Z; Haber, C; Hahn, S R; Halkiadakis, E; Hamaguchi, A; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harr, R F; Hatakeyama, K; Hays, C; Heck, M; Heinrich, J; Herndon, M; Hewamanage, S; Hidas, D; Hocker, A; Hopkins, W; Horn, D; Hou, S; Hughes, R E; Hurwitz, M; Husemann, U; Hussain, N; Hussein, M; Huston, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Ketchum, W; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirby, M; Klimenko, S; Kondo, K; Kong, D J; Konigsberg, J; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kuhr, T; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, E; Lee, H S; Lee, J S; Lee, S W; Leo, S; Leone, S; Lewis, J D; Lin, C-J; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, Q; Liu, T; Lockwitz, S; Lockyer, N S; Loginov, A; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; Madrak, R; Maeshima, K; Makhoul, K; Maksimovic, P; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Martínez, M; Martínez-Ballarín, R; Mastrandrea, P; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Mesropian, C; Miao, T; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Mondragon, M N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Fernandez, P Movilla; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakano, I; Napier, A; Nett, J; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Ortolan, L; Griso, S Pagan; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pondrom, L; Potamianos, K; Poukhov, O; Prokoshin, F; Pronko, A; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Renton, P; Rescigno, M; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rubbo, F; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Santi, L; Sartori, L; Sato, K; Saveliev, V; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shreyber, I; Siegrist, J; Simonenko, A; Sinervo, P; Sissakian, A; Sliwa, K; Smith, J R; Snider, F D; Soha, A; Somalwar, S; Sorin, V; Squillacioti, P; Stanitzki, M; Denis, R St; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Sudo, Y; Sukhanov, A; Suslov, I; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thome, J; Thompson, G A; Thomson, E; Ttito-Guzmán, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Vidal, M; Vila, I; Vilar, R; Volobouev, I; Vogel, M; Volpi, G; Wagner, P; Wagner, R L; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Wick, F; Williams, H H; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, H; Wright, T; Wu, X; Wu, Z; Yamamoto, K; Yamaoka, J; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanetti, A; Zeng, Y; Zucchelli, S
2010-12-17
A precision measurement of the top quark mass m(t) is obtained using a sample of tt events from pp collisions at the Fermilab Tevatron with the CDF II detector. Selected events require an electron or muon, large missing transverse energy, and exactly four high-energy jets, at least one of which is tagged as coming from a b quark. A likelihood is calculated using a matrix element method with quasi-Monte Carlo integration taking into account finite detector resolution and jet mass effects. The event likelihood is a function of m(t) and a parameter Δ(JES) used to calibrate the jet energy scale in situ. Using a total of 1087 events in 5.6 fb(-1) of integrated luminosity, a value of m(t)=173.0 ± 1.2 GeV/c(2) is measured.
Menendez, J.; Poves, A.
2009-10-15
We discuss the variation of the nuclear matrix element (NME) for the neutrinoless double beta (0{nu}{beta}{beta}) decay of {sup 76}Ge when the wave functions are constrained to reproduce the experimental occupancies of the two nuclei involved in the transition. In the interacting shell model description the value of the NME is enhanced about 15% compared to previous calculations, whereas in the QRPA the NME's are reduced by 20%-30%. This diminishes the discrepancies between both approaches. In addition, we discuss the effect of the short-range correlations on the NME in light of the recently proposed parametrizations based on a consistent renormalization of the 0{nu}{beta}{beta} transition operator.
Kirsch, Matthias
2009-06-29
At particle accelerators the Standard Model has been tested and will be tested further to a great precision. The data analyzed in this thesis have been collected at the world's highest energetic-collider, the Tevatron, located at the Fermi National Accelerator Laboratory (FNAL) in the vicinity of Chicago, IL, USA. There, protons and antiprotons are collided at a center-of-mass energy of {radical}s = 1.96 TeV. The discovery of the top quark was one of the remarkable results not only for the CDF and D0 experiments at the Tevatron collider, but also for the Standard Model, which had predicted the existence of the top quark because of symmetry arguments long before already. Still, the Tevatron is the only facility able to produce top quarks. The predominant production mechanism of top quarks is the production of a top-antitop quark pair via the strong force. However, the Standard Model also allows the production of single top quarks via the electroweak interaction. This process features the unique opportunity to measure the |V_{tb}| matrix element of the Cabbibo-Kobayashi-Maskawa (CKM) matrix directly, without assuming unitarity of the matrix or assuming that the number of quark generations is three. Hence, the measurement of the cross section of electroweak top quark production is more than the technical challenge to extract a physics process that only occurs one out of ten billion collisions. It is also an important test of the V-A structure of the electroweak interaction and a potential window to physics beyond the Standard Model in the case where the measurement of |V{sub tb}| would result in a value significantly different from 1, the value predicted by the Standard Model. At the Tevatron two production processes contribute significantly to the production of single top quarks: the production via the t-channel, also called W-gluon fusion, and the production via the s-channel, known as well as W* process. This analysis searches for the combined s+t channel
Am phases in the matrix of a U–Pu–Zr alloy with Np, Am, and rare-earth elements
Janney, Dawn E.; Kennedy, J. Rory; Madden, James W.; O’Holleran, Thomas P.
2015-01-01
Phases and microstructures in the matrix of an as-cast U-Pu-Zr alloy with 3 wt% Am, 2% Np, and 8% rare-earth elements were characterized by scanning and transmission electron microscopy. The matrix consists primarily of two phases, both of which contain Am: ζ-(U, Np, Pu, Am) (~70 at% U, 5% Np, 14% Pu, 1% Am, and 10% Zr) and δ-(U, Np, Pu, Am)Zr_{2} (~25% U, 2% Np, 10-15% Pu, 1-2% Am, and 55-60 at% Zr). These phases are similar to those in U-Pu-Zr alloys, although the Zr content in ζ-(U, Np, Pu, Am) is higher than that in ζ-(U, Pu) and the Zr content in δ-(U, Np, Pu, Am)Zr_{2} is lower than that in δ-UZr_{2}. Nanocrystalline actinide oxides with structures similar to UO2 occurred in some areas, but may have formed by reactions with the atmosphere during sample handling. Planar features consisting of a central zone of ζ-(U, Np, Pu, Am) bracketed by zones of δ-(U, Np, Pu, Am)Zr_{2} bound irregular polygons ranging in size from a few micrometers to a few tens of micrometers across. The rest of the matrix consists of elongated domains of ζ-(U, Np, Pu, Am) and δ-(U, Np, Pu, Am)Zr_{2}. Each of these domains is a few tens of nanometers across and a few hundred nanometers long. The domains display strong preferred orientations involving areas a few hundred nanometers to a few micrometers across.
NASA Astrophysics Data System (ADS)
Stafilov, Trajče; Zendelovska, Dragica; Pavlovska, Gorica; Čundeva, Katarina
2002-05-01
The interferences of Ca and Mg as matrix elements in dolomite and gypsum on Ag, Cd, Cr, Mn, Tl and Zn absorbances during their electrothermal atomic absorption spectrometric (ETAAS) determination are investigated. The results reveal that Ca and Mg do not interfere on Zn and Mn, tend to decrease absorbances of Ag, Cd and Cr, while Tl suffers the most significant influence. A flotation separation method is proposed to eliminate matrix interferences. Hydrated iron(III) oxide, Fe 2O 3· xH 2O, and iron(III) hexamethylenedithiocarbamate, Fe(HMDTC) 3, are applied as flotation collectors. The influence of hydrophobic dithiocarbamate anion, HMDTC, on flotation recoveries of each analyte is studied. The most suitable concentrations of dolomite and gypsum solutions for flotation are determined. To avoid flotation suppression due to the reaction of Ca 2+ and Mg 2+ with surfactant ions, a fit foaming agent was selected. The elements present in dolomite and gypsum as traces have been analyzed by ETAAS. Their ETAAS limits of detection following flotation are found to be 0.021 μg·g -1 for Ag, 0.019 μg·g -1 for Cd, 0.014 μg·g -1 for Cr and 0.11 μg·g -1 for Tl. The determination of Mn and Zn can be performed by flame AAS (FAAS). The limit of detection for Mn is 1.5 μg·g -1, while for Zn 0.8 μg·g -1.
Electromagnetic finite elements based on a four-potential variational principle
NASA Technical Reports Server (NTRS)
Schuler, James; Felippa, Carlos A.
1990-01-01
Electromagnetic finite elements based on a variational principle that uses the electromagnetic four-potential as primary variable are derived. This choice is used to construct elements suitable for downstream coupling with mechanical and thermal finite elements for the analysis of electromagnetic/mechanical systems that involve superconductors. The main advantages of the four-potential as a basis for finite element formulation are: (1) the number of degrees of freedom per node remains modest as the problem dimensionality increases, (2) jump discontinuities on interfaces are naturally accommodated, and (3) statics as well as dynamics may be treated without any a priori approximations. The new elements are tested on an axisymmetric problem under steady-state forcing conditions. The results are in excellent agreement with analytical solutions.
Electromagnetic finite elements based on a four-potential variational principle
NASA Technical Reports Server (NTRS)
Schuler, James J.; Felippa, Carlos A.
1991-01-01
Electromagnetic finite elements based on a variational principle that uses the electromagnetic four-potential as a primary variable are derived. This choice is used to construct elements suitable for downstream coupling with mechanical and thermal finite elements for the analysis of electromagnetic/mechanical systems that involve superconductors. The main advantages of the four-potential as a basis for finite element formulation are that the number of degrees of freedom per node remains modest as the problem dimensionally increases, that jump discontinuities on interfaces are naturally accommodated, and that statics as well as dynamics may be treated without any a priori approximations. The new elements are tested on an axisymmetric problem under steady state forcing conditions. The results are in excellent agreement with analytical solutions.
NASA Technical Reports Server (NTRS)
Thuemmel, Helmar T.; Huo, Winifred M.; Langhoff, Stephen R. (Technical Monitor)
1995-01-01
For the calculation of electron molecule collision cross sections R-matrix methods automatically take advantage of the division of configuration space into an inner region (I) bounded by radius tau b, where the scattered electron is within the molecular charge cloud and the system is described by an correlated Configuration Interaction (CI) treatment in close analogy to bound state calculations, and an outer region (II) where the scattered electron moves in the long-range multipole potential of the target and efficient analytic methods can be used for solving the asymptotic Schroedinger equation plus boundary conditions.
Quantum Monte Carlo with density matrix: potential energy curve derived properties.
Bonfim, Víctor S; Borges, Nádia M; Martins, João B L; Gargano, Ricardo; Politi, José Roberto Dos S
2017-04-01
In this work, we used diffusion quantum Monte Carlo with density matrix (d-DMC) and variational quantum Monte Carlo (d-VMC) to determine the potential energy curve (PEC) and obtain the spectroscopic constants of H2 molecule in the ground state, in order to evaluate the capability of these methods to provide an accurate PEC description. These quantum Monte Carlo methods build with density matrix are new approaches to conventional quantum Monte Carlo methods based on wave function formed by product of α and β determinants. To investigate the robustness of d-DMC, we performed calculations with two different basis sets and analyzed the influence of the size of these sets on results. To the best of our knowledge, this is the first study that shows the dissociation energy and rotational constant obtained from d-QMC. We found that the quality of PEC described by the d-DMC is essentially coincident with the most accurate results available in the literature, regardless of the complexity of basis set employed.
Shimada, Nao; Nishio, Keiko; Maeda, Mineko; Urushihara, Hideko; Kawata, Takefumi
2004-10-01
Dd-STATa is a functional Dictyostelium homologue of metazoan STAT (signal transducers and activators of transcription) proteins, which is activated by cAMP and is thereby translocated into the nuclei of anterior tip cells of the prestalk region of the slug. By using in situ hybridization analyses, we found that the SLF308 cDNA clone, which contains the ecmF gene that encodes a putative extracellular matrix protein and is expressed in the anterior tip cells, was greatly down-regulated in the Dd-STATa-null mutant. Disruption of the ecmF gene, however, resulted in almost no phenotypic change. The absence of any obvious mutant phenotype in the ecmF-null mutant could be due to a redundancy of similar genes. In fact, a search of the Dictyostelium whole genome database demonstrates the existence of an additional 16 homologues, all of which contain a cellulose-binding module. Among these homologues, four genes show Dd-STATa-dependent expression, while the others are Dd-STATa-independent. We discuss the potential role of Dd-STATa in morphogenesis via its effect on the interaction between cellulose and these extracellular matrix family proteins.
Time Dependent Channel Packet Calculation of Two Nucleon Scattering Matrix Elements
2010-03-01
3.2. Feynman Diagram of a Pi Meson Exchange ........................................................... 26 3.3. Centripetal Potential centV...25 5. Approximate Meson Masses, Lifetimes ( t∆ ) and Ranges ( x∆ ) ................................ 27 6. ( )Rv pp Strong Component...where k is the wave vector . Indeed with the exception of some time-dependent momentum space calculations performed by Holz and Glöckle [12,34] and a
The Potential Impacts on Aquatic Ecosystems from the Release of Trace Elements in Geothermal Fluids
Cushman, R.M.
2000-03-14
Geothermal energy will likely constitute an increasing percentage of our nation's future energy ''mix,'' both for electrical and nonelectrical uses. Associated with the exploitation of geothermal resources is the handling and disposal of fluids which contain a wide variety of potentially toxic trace elements. We present analyses of 14 trace elements found in hydrothermal fluids from various geothermal reservoirs in the western United States. The concentrations of these elements vary over orders of magnitude between reservoirs. Potential impacts are conservatively assessed on the basis of (1) toxicity to freshwater biota, and (2) bioaccumulation in food fish to the point where consumption might be hazardous to human health. Trace element concentrations generally range from benign levels to levels which might prove toxic to freshwater biota and contaminate food fisheries. We stress the need for site-specific analyses and careful handling of geothermal fluids in order to minimize potential impacts.
A tale of two dead ends: origin of a potential new gene and a potential new transposable element.
Clutterbuck, A John
2007-03-01
An article in this issue of Molecular Microbiology by Cultrone et al. describes how a non-autonomous helitron element could arise from its autonomous parent transposon by deletion followed by readthrough into an adjacent gene and its promoter, thus providing a mechanism for distribution of a specifically regulated promoter sequence around the genome, where it would have the potential to evolve new functions.
NASA Technical Reports Server (NTRS)
Abdul-Aziz, Ali; Baaklini, George Y.; Bhatt, Ramakrishna T.
2003-01-01
Most reverse engineering approaches involve imaging or digitizing an object and then creating a computerized reconstruction that can be integrated, in three dimensions, into a particular design environment. The rapid prototyping technique builds high-quality physical prototypes directly from computer-aided design files. This fundamental technique for interpreting and interacting with large data sets is being used here via Velocity2 (an integrated image-processing software, ref. 1) using computed tomography (CT) data to produce a prototype three-dimensional test specimen model for analyses. A study at the NASA Glenn Research Center proposes to use these capabilities to conduct a combined nondestructive evaluation (NDE) and finite element analysis (FEA) to screen pretest and posttest structural anomalies in structural components. A tensile specimen made of silicon nitrite (Si3N4) ceramic matrix composite was considered to evaluate structural durability and deformity. Ceramic matrix composites are being sought as candidate materials to replace nickel-base superalloys for turbine engine applications. They have the unique characteristics of being able to withstand higher operating temperatures and harsh combustion environments. In addition, their low densities relative to metals help reduce component mass (ref. 2). Detailed three-dimensional volume rendering of the tensile test specimen was successfully carried out with Velocity2 (ref. 1) using two-dimensional images that were generated via computed tomography. Subsequent, three-dimensional finite element analyses were performed, and the results obtained were compared with those predicted by NDE-based calculations and experimental tests. It was shown that Velocity2 software can be used to render a three-dimensional object from a series of CT scan images with a minimum level of complexity. The analytical results (ref. 3) show that the high-stress regions correlated well with the damage sites identified by the CT scans
Trivial center element and Coulombic potential of the thick center vortex model
NASA Astrophysics Data System (ADS)
Ahmadi, Alireza; Rafibakhsh, Shahnoosh
2017-01-01
The thick center vortex potentials in the SU(3) gauge group have been calculated by means of the modified inter-quark potential which consists of two terms. One term is the result of the area law fall-off for the large Wilson loop which leads to the linear potentials. The second term represents vacuum fluctuations leading to the perimeter law fall-off believed to contain the trivial center element. We introduce a new Gaussian flux limited to vary in a finite region of space which causes the corresponding group factor to have only some small deviations from the trivial center element. So, this flux increases the role of the trivial center element and W0 is enhanced in the induced potential of the model at small quark separations. Using both trivial and non-trivial center elements in the potential between static color sources, results in the correct 3-ality dependence at large quark separations and a very good agreement with Casimir scaling at short and intermediate distances. In fact, the ratios of the potential of each representation to that of the fundamental one have been improved - in comparison with the previous work on the short distance potentials, remarkably. So, one might use the thick center vortex model to describe the inter-quark potential of every regime.
NASA Astrophysics Data System (ADS)
Krebs, Derek; Budynas, Richard G.
A common procedure for performing a cross orthogonality check for the purpose of modal correlation between the test and the finite element analysis results incorporates the Guyan reduction method to obtain a reduced mass matrix. This paper describes a procedure which uses NASTRAN's Generalized Dynamic Reduction solution routine which is much more accurate than the standard Guyan reduction solution and which offers the advantage of not requiring the selection of mdof. Using NASTRAN's DMAP programming methods, a modal reduction of the full analytical mass matrix is performed based on the accelerometer locations and the analytical modal matrix results. The accuracy of the procedure is illustrated in two case studies.
Majer, Alessandra Pereira; Petti, Mônica Angélica Varella; Corbisier, Thais Navajas; Ribeiro, Andreza Portella; Theophilo, Carolina Yume Sawamura; Ferreira, Paulo Alves de Lima; Figueira, Rubens Cesar Lopes
2014-02-15
Data about the concentration, accumulation and transfer of potentially toxic elements in Antarctic marine food webs are essential for understanding the impacts of these elements, and for monitoring the pollution contribution of scientific stations, mainly in Admiralty Bay due to the 2012 fire in the Brazilian scientific station. Accordingly, the concentration of As, Cd, Cu, Ni, Pb and Zn was measured in eight benthic species collected in the 2005/2006 austral summer and the relationship between concentration and trophic position (indicated by δ(15)N values) was tested. A wide variation in metal content was observed depending on the species and the element. In the studied trophic positions, it was observed bioaccumulation for As, Cd and Pb, which are toxic elements with no biological function. In addition, Cd showed a positive relationship between concentration and trophic level suggesting the possible biomagnification of this element.
NASA Astrophysics Data System (ADS)
Schubert, A.; Götze, U.; Hackert-Oschätzchen, M.; Lehnert, N.; Herold, F.; Meichsner, G.; Schmidt, A.
2016-03-01
Compared to conventional cutting, the processing of materials by electrochemical machining offers some technical advantages like high surface quality, no thermal or mechanical impact on the work piece and preservation of the microstructure of the work piece material. From the economic point of view, the possibility of process parallelization and the absence of any process-related tool wear are mentionable advantages of electrochemical machining. In this study, based on experimental results, it will be evaluated to what extent the electrochemical machining is technically and economically suitable for the finish-machining of particle- reinforced aluminum matrix composites (AMCs). Initial studies showed that electrochemical machining - in contrast to other machining processes - has the potential to fulfil demanding requirements regarding precision and surface quality of products or components especially when applied to AMCs. In addition, the investigations show that processing of AMCs by electrochemical machining requires less energy than the electrochemical machining of stainless steel. Therefore, an evaluation of electrochemically machined AMCs - compared to stainless steel - from a technical and an economic perspective will be presented in this paper. The results show the potential of electro-chemically machined AMCs and contribute to the enhancement of instruments for technical-economic evaluations as well as a comprehensive innovation control.
Venugopal, Archana; Uma Maheswari, T N
2016-01-01
Matrix metalloproteinase-9 (MMP-9) is an inducible enzyme. Oral potentially malignant disorders (OPMDs) are considered as the early tissue changes that happen due to various habits such as smoking tobacco, chewing tobacco or stress. This alteration in the tissues alters the expression of MMP-9. The rationale of the review is to know the expression of MMP-9 in OPMDs. Hand searching and electronic databases such as PubMed and ScienceDirect were done for mesh terms such as OPMDs and MMP-9. Eight articles were obtained, after applying inclusion and exclusion criteria. These articles were assessed with QUADAS and data were extracted and evaluated. The included eight studies were done in 182 oral squamous cell carcinoma cases, 430 OPMDs (146 oral lichen planus, 264 leukoplakia and 20 oral submucous fibrosis) and 352 healthy controls evaluated for MMP-9. MMP-9 expression was found to be elevated in tissue, serum and saliva samples of OPMDs than in healthy controls. There is only one study in each serum and saliva samples to evaluate MMP-9. Saliva being noninvasive and serum being minimally invasive, more studies need to be done in both serum and saliva to establish MMP-9 as an early diagnostic marker in OPMDs to know its potential in malignant transformation.
Figueiredo, Maurilio Assis; Leite, Mariangela Garcia Praça; Kozovits, Alessandra Rodrigues
2016-01-01
Understanding the factors that control uptake rates and allocation of chemical elements among plant organs is a fundamental prerequisite to improve phytostabilization techniques of hazardous elements in contaminated areas. The present study shows evidence that different substrate textures (coarse and fine laterite) do not significantly change the partitioning of root and shoot dry biomass and with few exceptions, do not significantly affect the final average concentration of elements in Eremanthus erythropappus, but change the root:shoot allocation of both essential nutrients and elements potentially toxic to biota. Growth on coarse laterite resulted in significant higher K (30%), Mg (34%), P (25%), S (32%), Cu (58%), and Na (43%) concentrations in roots and lower Cd concentration (29%). In shoots, coarse laterite led to reduction in K, Fe, Al, and Cr and increase in Na and Sr concentrations. Changes in element allocation could be, in part, a result of differences in the water availability of substrates. Matric potential in coarse laterite was significantly lower in at least 47% of the days analyzed throughout the year. Changes in element phytoextraction or phytostabilization potential could influence the efficiency of rehabilitation projects in areas degraded by mining activities.
Plant-soil distribution of potentially toxic elements in response to elevated atmospheric CO2.
Duval, Benjamin D; Dijkstra, Paul; Natali, Susan M; Megonigal, J Patrick; Ketterer, Michael E; Drake, Bert G; Lerdau, Manuel T; Gordon, Gwyneth; Anbar, Ariel D; Hungate, Bruce A
2011-04-01
The distribution of contaminant elements within ecosystems is an environmental concern because of these elements' potential toxicity to animals and plants and their ability to hinder microbial ecosystem services. As with nutrients, contaminants are cycled within and through ecosystems. Elevated atmospheric CO2 generally increases plant productivity and alters nutrient element cycling, but whether CO2 causes similar effects on the cycling of contaminant elements is unknown. Here we show that 11 years of experimental CO2 enrichment in a sandy soil with low organic matter content causes plants to accumulate contaminants in plant biomass, with declines in the extractable contaminant element pools in surface soils. These results indicate that CO2 alters the distribution of contaminant elements in ecosystems, with plant element accumulation and declining soil availability both likely explained by the CO2 stimulation of plant biomass. Our results highlight the interdependence of element cycles and the importance of taking a broad view of the periodic table when the effects of global environmental change on ecosystem biogeochemistry are considered.
Source imaging of potential fields through a matrix space-domain algorithm
NASA Astrophysics Data System (ADS)
Baniamerian, Jamaledin; Oskooi, Behrooz; Fedi, Maurizio
2017-01-01
Imaging of potential fields yields a fast 3D representation of the source distribution of potential fields. Imaging methods are all based on multiscale methods allowing the source parameters of potential fields to be estimated from a simultaneous analysis of the field at various scales or, in other words, at many altitudes. Accuracy in performing upward continuation and differentiation of the field has therefore a key role for this class of methods. We here describe an accurate method for performing upward continuation and vertical differentiation in the space-domain. We perform a direct discretization of the integral equations for upward continuation and Hilbert transform; from these equations we then define matrix operators performing the transformation, which are symmetric (upward continuation) or anti-symmetric (differentiation), respectively. Thanks to these properties, just the first row of the matrices needs to be computed, so to decrease dramatically the computation cost. Our approach allows a simple procedure, with the advantage of not involving large data extension or tapering, as due instead in case of Fourier domain computation. It also allows level-to-drape upward continuation and a stable differentiation at high frequencies; finally, upward continuation and differentiation kernels may be merged into a single kernel. The accuracy of our approach is shown to be important for multi-scale algorithms, such as the continuous wavelet transform or the DEXP (depth from extreme point method), because border errors, which tend to propagate largely at the largest scales, are radically reduced. The application of our algorithm to synthetic and real-case gravity and magnetic data sets confirms the accuracy of our space domain strategy over FFT algorithms and standard convolution procedures.
Karachalios, Charalampos; Bakas, Panagiotis; Kaparos, Georgios; Demeridou, Styliani; Liapis, Ilias; Grigoriadis, Charalampos; Liapis, Aggelos
2016-01-01
Pelvic organ prolapse (POP) is a common multifactorial condition. Matrix metalloproteinases (MMPs) are enzymes capable of breaking down various connective tissue elements. Single-nucleotide polymorphisms (SNPs) in regulatory areas of MMP-encoding genes can alter their transcription rate, and therefore the possible effect on pelvic floor supporting structures. The insertion of an adenine (A) base in the promoter of the MMP-3 gene at position −1612/−1617 produces a sequence of six adenines (6A), whereas the other allele has five (5A). The aim of the present study was to investigate the possible association of MMP-3 gene promoter SNPs with the risk of POP. The patient group comprised 80 women with clinically significant POP [Stage II, III or IV; POP quantification (POP-Q) system]. The control group consisted of 80 females without any or important pelvic floor support defects (Stages 0 or I; POP-Q system). All the participants underwent the same preoperative evaluation. SNP detection was determined with whole blood sample DNA analysis by quantitative polymerase chain reaction (PCR) in LightCycler® PCR platforms, using the technique of sequence-specific hybridization probe-binding assays and melting temperature curve analysis. The results showed there was no statistically significant difference between 5A/5A, 5A/6A and 6A/6A MMP-3 gene promoter variants in the two study groups (P=0.4758). Therefore, MMP-3 gene promoter SNPs alone is insufficient to increase the genetic susceptibility to POP development. PMID:27588175
NASA Technical Reports Server (NTRS)
Schuler, James J.; Felippa, Carlos A.
1991-01-01
Electromagnetic finite elements are extended based on a variational principle that uses the electromagnetic four potential as primary variable. The variational principle is extended to include the ability to predict a nonlinear current distribution within a conductor. The extension of this theory is first done on a normal conductor and tested on two different problems. In both problems, the geometry remains the same, but the material properties are different. The geometry is that of a 1-D infinite wire. The first problem is merely a linear control case used to validate the new theory. The second problem is made up of linear conductors with varying conductivities. Both problems perform well and predict current densities that are accurate to within a few ten thousandths of a percent of the exact values. The fourth potential is then removed, leaving only the magnetic vector potential, and the variational principle is further extended to predict magnetic potentials, magnetic fields, the number of charge carriers, and the current densities within a superconductor. The new element produces good results for the mean magnetic field, the vector potential, and the number of superconducting charge carriers despite a relatively high system condition number. The element did not perform well in predicting the current density. Numerical problems inherent to this formulation are explored and possible remedies to produce better current predicting finite elements are presented.
NASA Technical Reports Server (NTRS)
Chackerian, C., Jr.
1976-01-01
The electric dipole moment function of the ground electronic state of carbon monoxide has been determined by combining numerical solutions of the radial Schrodinger equation with absolute intensity data of vibration-rotation bands. The derived dipole moment function is used to calculate matrix elements of interest to stellar astronomy and of importance in the carbon monoxide laser.
Freeman, John
2007-01-01
A measurement of the top quark mass in t$\\bar{t}$ → l + jets candidate events, obtained from p$\\bar{p}$ collisions at √s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector, is presented. The measurement approach is that of a matrix element method. For each candidate event, a two dimensional likelihood is calculated in the top pole mass and a constant scale factor, 'JES', where JES multiplies the input particle jet momenta and is designed to account for the systematic uncertainty of the jet momentum reconstruction. As with all matrix element techniques, the method involves an integration using the Standard Model matrix element for t$\\bar{t}$ production and decay. However, the technique presented is unique in that the matrix element is modified to compensate for kinematic assumptions which are made to reduce computation time. Background events are dealt with through use of an event observable which distinguishes signal from background, as well as through a cut on the value of an event's maximum likelihood. Results are based on a 955 pb^{-1} data sample, using events with a high-p_{T} lepton and exactly four high-energy jets, at least one of which is tagged as coming from a b quark; 149 events pass all the selection requirements. They find M_{meas} = 169.8 ± 2.3(stat.) ± 1.4(syst.) GeV/c^{2}.
Freeman, John C
2007-01-01
A measurement of the top quark mass in t$\\bar{t}$ → l + jets candidate events, obtained from p$\\bar{p}$ collisions at √s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector, is presented. The measurement approach is that of a matrix element method. For each candidate event, a two dimensional likelihood is calculated in the top pole mass and a constant scale factor, 'JES', where JES multiplies the input particle jet momenta and is designed to account for the systematic uncertainty of the jet momentum reconstruction. As with all matrix elements techniques, the method involves an integration using the Standard Model matrix element for tt production and decay. however, the technique presented is unique in that the matrix element is modified to compensate for kinematic assumptions which are made to reduce computation time. Background events are dealt with through use of an event observable which distinguishes signal from background, as well as through a cut on the value of an event's maximum likelihood. Results are based on a 955 pb^{-1 }data sample, using events with a high-p_{T} lepton and exactly four high-energy jets, at least one of which is tagged as coming from a b quark; 149 events pass all the selection requirements. They find M_{meas} = 169.8 ± 2.3(stat.) ± 1.4(syst.) GeV/c^{2}.
Kaon matrix elements and CP violation from lattice QCD with 2+1 flavors of domain wall fermions
NASA Astrophysics Data System (ADS)
Li, Shu
Low energy constants describing the weak, two-pion decays of K mesons in chiral perturbation theory are computed using 2+1 flavors of domain wall fermions in a finite volume with spatial extent 2.74 fm and for a single inverse lattice spacing 1/a = 1.73 GeV. Partially quenched perturbation theory is used in both leading and next-to-leading order. The non-perturbative regularization independent RI/MOM renormalization scheme is employed to determine these low energy constants in the continuum, RI normalization scheme with 20% statistical errors but systematic errors which are estimated to lie between 50 and 100% depending on the operator. These low energy constants are then used to estimate the DeltaI = 1/2 and DeltaI = 3/2 K → pipi decay matrix elements and epsilon'/epsilon. The poor convergence of chiral perturbation theory for quark masses as large as that of the strange quark severely limits the accuracy of these results.
NASA Astrophysics Data System (ADS)
Della Morte, Michele; Giusti, Leonardo
2011-05-01
We make use of the global symmetries of the Yang-Mills theory on the lattice to design a new computational strategy for extracting glueball masses and matrix elements which achieves an exponential reduction of the statistical error with respect to standard techniques. By generalizing our previous work on the parity symmetry, the partition function of the theory is decomposed into a sum of path integrals each giving the contribution from multiplets of states with fixed quantum numbers associated to parity, charge conjugation, translations, rotations and central conjugations Z N 3. Ratios of path integrals and correlation functions can then be computed with a multi-level Monte Carlo integration scheme whose numerical cost, at a fixed statistical precision and at asymptotically large times, increases power-like with the time extent of the lattice. The strategy is implemented for the SU(3) Yang-Mills theory, and a full-fledged computation of the mass and multiplicity of the lightest glueball with vacuum quantum numbers is carried out at a lattice spacing of 0.17 fm.
NASA Astrophysics Data System (ADS)
Pipes, Leonard C.; Kim, Dae Young; Brandstater, Nathan; Fuglesang, Christopher D.; Baugh, Delroy
1995-12-01
The photofragmentation of rovibrational energy-level and magnetic-state polarized ( overlineX1A 1)CD 3I ∣JKM>≡∣111> was performed at 266 nm. The ∣ NK) rotational energy level distribution and the angular momentum polarization of the vibrationless ( overlineX2A″ 2) CD 3 photofragment were measured by (2+1) REMPI. State-selecting the parent CD 3I allowed the elements of the transition dipole matrix (or T-matrix) to be determined by relating the initial system (CD 3I plus photon) statistical tensors to measured product statistical moments. This is believed to be the first report of the experimental determination of T-matrix elements for a chemical reaction.
Choi, Ji Suk; Kim, Beob Soo; Kim, Jun Young; Kim, Jae Dong; Choi, Young Chan; Yang, Hyun-Jin; Park, Kinam; Lee, Hee Young; Cho, Yong Woo
2011-06-01
Decellularized tissues composed of extracellular matrix (ECM) have been clinically used to support the regeneration of various human tissues and organs. Most decellularized tissues so far have been derived from animals or cadavers. Therefore, despite the many advantages of decellularized tissue, there are concerns about the potential for immunogenicity and the possible presence of infectious agents. Herein, we present a biomaterial composed of ECM derived from human adipose tissue, the most prevalent, expendable, and safely harvested tissue in the human body. The ECM was extracted by successive physical, chemical, and enzymatic treatments of human adipose tissue isolated by liposuction. Cellular components including nucleic acids were effectively removed without significant disruption of the morphology or structure of the ECM. Major ECM components were quantified, including acid/pepsin-soluble collagen, sulfated glycosaminoglycan (GAG), and soluble elastin. In an in vivo experiment using mice, the decellularized ECM graft exhibited good compatibility to surrounding tissues. Overall results suggest that the decellularized ECM containing biological and chemical cues of native human ECM could be an ideal scaffold material not only for autologous but also for allograft tissue engineering.
ERIC Educational Resources Information Center
Hanson, J. Robert
Matrix organization focuses on the shift from cost center or process input planning to product output or results planning. Matrix organization puts the personnel and the resources where they are needed to get the job done. This management efficiency is brought about by dividing all organizational activities into two areas: (1) input or maintenance…
Qin, Yi-Xian; Lam, Hoyan
2010-01-01
Intramedullary pressure (ImP) and low-level bone strain induced by oscillatory muscle stimulation (MS) has the potential to mitigate bone loss induced by disuse osteopenia, i.e., hindlimb suspension (HLS). To test this hypothesis, we evaluated a) MS induced ImP and bone strain as function of stimulation frequency, and b) the adaptive responses to functional disuse, and disuse plus 1Hz and 20Hz stimulation in vivo. Femoral ImP and bone strain generated by MS were measured in the frequencies of 1Hz-100Hz in four rats. Forty retired breeder rats were used for the in vivo HLS study. The quadriceps muscle was stimulated at frequencies of 1 Hz and 20 Hz, 10min/d for 4 weeks. The metaphyseal trabecular bone quantity and microstructure at the distal femur were evaluated using μCT, while bone formation indices were analyzed using histomorphometric techniques. Oscillatory MS generated a maximum ImP of 45±9 mmHg at 20 Hz and produced a maximum matrix strain of 128±19 με at 10 Hz. Our analyses from the in vivo study showed that MS at 20 Hz was able to attenuate trabecular bone loss and partially maintain the microstructure induced by HLS. Conversely, there was no evidence of an adaptive effect of stimulation at 1 Hz on disused skeleton. The results suggested that oscillatory MS regulates fluid dynamics and mechanical strain in bone, which serves as a critical mediator of adaptation. These results clearly demonstrated the ability of MS in attenuating bone loss from the disuse osteopenia and could hold potential in mitigating skeletal degradation imposed by conditions of disuse, which may serve as a biomechanical intervention in clinic application. PMID:19081096
Electromagnetic axisymmetric finite elements based on a gauged four-potential variational principle
NASA Technical Reports Server (NTRS)
Schuler, J.; Felippa, C. A.
1990-01-01
Electromagnetic finite elements are derived based on a variational principle that uses the electromagnetic four-potential as a primary variable. The Lorentz gage normalization is incorporated as a constraint condition through a Lagrange multiplier field to construct elements suitable for downstream coupling with mechanical and thermal finite elements for the analysis of high-temperature superconductor devices with aerospace applications. The main advantages are: jump discontinuities on interfaces are naturally handled; no a priori approximations are invoked; and the number of degrees of freedom per node remains modest as the problem dimensionality increases. The new elements are tested on two magnetostatic axisymmetric problems. The results are in excellent agreement with analytical solutions and previous solutions for the 1D problem of a conducting infinite wire, in which case the multiplier field has no effect. For materials of widely different permeability, jump conditions are naturally accommodated by the present formulation.
A fiber matrix model for fluid flow and streaming potentials in the canaliculi of an osteon
NASA Technical Reports Server (NTRS)
Zeng, Y.; Cowin, S. C.; Weinbaum, S.
1994-01-01
A theoretical model is developed to predict the fluid shear stress and streaming potential at the surface of osteocytic processes in the lacunar-canalicular porosity of an osteon when the osteon is subject to mechanical loads that are parallel or perpendicular to its axis. The theory developed in Weinbaum et al. (31) for the flow through a proteoglycan matrix in a canaliculus is employed in a poroelastic model for the osteon. Our formulation is a generalization of that of Petrov et al. (17). Our model predicts that, in order to satisfy the measured frequency dependence of the phase and magnitude of the SGP in macroscopic bone samples, the fiber spacing in the fluid annulus must lie in the narrow range 6-7 nm typical of the spacing of GAG sidechains along a protein monomer. The model predictions for the local SGP profiles in the osteon agree with the experimental observations of Starkebaum et al. (24). The theory predicts that the pore pressure relaxation time, tau d, for a 150-300 microns diameter osteon with the foregoing matrix structure is approximately 0.03-0.13 sec, and that the amplitude of the mean fluid shear stress on the membrane of the osteocytic process at the mean areal radius of the osteon has a maximum at 28 Hz if tau d = 0.06 sec. This maximum, which is independent of the magnitude of the loading, could be important in vivo since the recent experiments of Turner et al. (28) and McLeod et al. (15) have a peak in the strain frequency spectrum between 20 and 30 Hz that also appears to be independent of the type (magnitude) of loading. Numerical predictions for the amplitude of the average fluid shear stress on the osteocytic membrane at the mean areal radius of the osteon show that the fluid shear stress associated with the low amplitude 20-30 Hz spectral strain component is at least as large as the average fluid shear stress associated with the high amplitude 1 Hz stride component, although the latter loading is an order of magnitude larger, and has a
Grounded or submerged bulk carrier: the potential for leaching of coal trace elements to seawater.
Lucas, Steven Andrew; Planner, John
2012-05-01
This study investigates the potential for leaching of coal trace elements to seawater from a grounded bulk carrier. The coal type and ecological scenario was based on the grounding of the "Shen Neng" (April 2010) at Douglas Shoal located within the Great Barrier Reef (Queensland, Australia). The area is of high ecological value and the Queensland Water Quality Guidelines (2009) provided threshold limits to interpret potential impacts. Coal contains many trace elements that are of major and moderate concern to human health and the environment although many of these concerns are only realised when coal is combusted. However, "unburnt" coal contains trace elements that may be leached to natural waterways and few studies have investigated the potential ecological impact of such an occurrence. For example, coal maritime transport has increased by almost 35% over the last five reported years (Jaffrennou et al., 2007) and as a result there is an increased inherent risk of bulk carrier accidents. Upon grounding or becoming submerged, coal within a bulk carrier may become saturated with seawater and potentially leach trace elements to the environment and impact on water quality and ecological resilience. The worst case scenario is the breakup of a bulk carrier and dispersal of cargo to the seafloor.
NASA Technical Reports Server (NTRS)
Haviland, J. K.; Yoo, Y. S.
1976-01-01
Expressions for calculation of subsonic and supersonic, steady and unsteady aerodynamic forces are derived, using the concept of aerodynamic elements applied to the downwash velocity potential method. Aerodynamic elements can be of arbitrary out of plane polygon shape, although numerical calculations are restricted to rectangular elements, and to the steady state case in the supersonic examples. It is suggested that the use of conforming, in place of rectangular elements, would give better results. Agreement with results for subsonic oscillating T tails is fair, but results do not converge as the number of collocation points is increased. This appears to be due to the form of expression used in the calculations. The methods derived are expected to facilitate automated flutter analysis on the computer. In particular, the aerodynamic element concept is consistent with finite element methods already used for structural analysis. The method is universal for the complete Mach number range, and, finally, the calculations can be arranged so that they do not have to be repeated completely for every reduced frequency.
Antoniadis, Vasileios; Golia, Evangelia E; Shaheen, Sabry M; Rinklebe, Jörg
2017-04-01
Elevated concentrations of potentially toxic elements (PTEs) are usually found in areas of intense industrial activity. Thriasio Plain is a plain near Athens, Greece, where most of the heavy industry of the country has been situated for decades, but it also is a residential and horticultural area. We aimed at measuring the levels of PTEs in soils and indigenous plant species and assessing the health risk associated with direct soil ingestion. Samples of soils at roadsides and growing plants were collected from 31 sites of that area. Concentrations of Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, V and Zn were measured in both soils (as pseudo-total) and aerial plant tissues. We found that As, Cd, Cr, Cu, Ni, Pb and Zn were higher than maximum regulatory limits. Element concentrations in plants were rather lower than expected, probably because indigenous plants have developed excluder behaviour over time. Copper and Zn soil-to-plant coefficients were highest among the other elements; for Cu this was unexpected, and probably associated with recent Cu-releasing industrial activity. Risk assessment analysis indicated that As was the element contributing more than 50 % of the health risk related to direct soil ingestion, followed by Cr, Pb, and, surprisingly, Mn. We concluded that in a multi-element contamination situation, elevated risk of PTEs (such as As, Cr and Pb) may reduce the tolerance limits of exposure to less-toxic elements (here, Mn).
NASA Astrophysics Data System (ADS)
Azizur Rahman, M.; Fujimura, Hiroyuki; Shinjo, Ryuichi; Oomori, Tamotsu
2011-06-01
In this study, we demonstrate a key function of extracellular matrix proteins (ECMPs) on seed crystals, which are isolated from calcified endoskeletons of soft coral and contain only CaCO 3 without any living cells. This is the first report that an ECMP protein extracted from a marine organism could potentially influence in modifying the surface of a substrate for designing materials via crystallization. We previously studied with the ECMPs from a different type of soft coral ( Sinularia polydactyla) without introducing any seed crystals in the process , which showed different results. Thus, crystallization on the seed in the presence of ECMPs of present species is an important first step toward linking function to individual proteins from soft coral. For understanding this interesting phenomenon, in vitro crystallization was initiated in a supersaturated solution on seed particles of calcite (1 0 4) with and without ECMPs. No change in the crystal growth shape occurred without ECMPs present during the crystallization process. However, with ECMPs, the morphology and phase of the crystals in the crystallization process changed dramatically. Upon completion of crystallization with ECMPs, an attractive crystal morphology was found. Scanning electron microscopy (SEM) was utilized to observe the crystal morphologies on the seeds surface. The mineral phases of crystals nucleated by ECMPs on the seeds surface were examined by Raman spectroscopy. Although 50 mM Mg 2+ is influential in making aragonite in the crystallization process, the ECMPs significantly made calcite crystals even when 50 mM Mg 2+ was present in the process. Crystallization with the ECMP additive seems to be a technically attractive strategy to generate assembled micro crystals that could be used in crystals growth and design in the Pharmaceutical and biotechnology industries.
2012-01-01
Background Mycosphaerella fijiensis is a ascomycete that causes Black Sigatoka in bananas. Recently, the M. fijiensis genome was sequenced. Repetitive sequences are ubiquitous components of fungal genomes. In most genomic analyses, repetitive sequences are associated with transposable elements (TEs). TEs are dispersed repetitive DNA sequences found in a host genome. These elements have the ability to move from one location to another within the genome, and their insertion can cause a wide spectrum of mutations in their hosts. Some of the deleterious effects of TEs may be due to ectopic recombination among TEs of the same family. In addition, some transposons are physically linked to genes and can control their expression. To prevent possible damage caused by the presence of TEs in the genome, some fungi possess TE-silencing mechanisms, such as RIP (Repeat Induced Point mutation). In this study, the abundance, distribution and potential impact of TEs in the genome of M. fijiensis were investigated. Results A total of 613 LTR-Gypsy and 27 LTR-Copia complete elements of the class I were detected. Among the class II elements, a total of 28 Mariner, five Mutator and one Harbinger complete elements were identified. The results of this study indicate that transposons were and are important ectopic recombination sites. A distribution analysis of a transposable element from each class of the M. fijiensis isolates revealed variable hybridization profiles, indicating the activity of these elements. Several genes encoding proteins involved in important metabolic pathways and with potential correlation to pathogenicity systems were identified upstream and downstream of transposable elements. A comparison of the sequences from different transposon groups suggested the action of the RIP silencing mechanism in the genome of this microorganism. Conclusions The analysis of TEs in M. fijiensis suggests that TEs play an important role in the evolution of this organism because the
Vernarsky, Brian J.
2014-01-01
In an effort towards a ''complete'' experiment for the ω meson, we present studies from an experiment with an unpolarized target and a circularly polarized photon beam (g1c), carried out using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The experiment was analyzed using an extended maximum likelihood fit with partial wave amplitudes. New likelihood functions were calculated to account for the polarization of the photon beam. Both circular and linear polarizations are explored. The results of these fits are then used to project out the spin density matrix for the {omega}. First measurements of the {rho}{sup 3} spin density matrix elements will be presented using this method.
First-principles interatomic potentials for ten elemental metals via compressed sensing
NASA Astrophysics Data System (ADS)
Seko, Atsuto; Takahashi, Akira; Tanaka, Isao
2015-08-01
Interatomic potentials have been widely used in atomistic simulations such as molecular dynamics. Recently, frameworks to construct accurate interatomic potentials that combine a set of density functional theory (DFT) calculations with machine learning techniques have been proposed. One of these methods is to use compressed sensing to derive a sparse representation for the interatomic potential. This facilitates the control of the accuracy of interatomic potentials. In this study, we demonstrate the applicability of compressed sensing to deriving the interatomic potential of ten elemental metals, namely, Ag, Al, Au, Ca, Cu, Ga, In, K, Li, and Zn. For each elemental metal, the interatomic potential is obtained from DFT calculations using elastic net regression. The interatomic potentials are found to have prediction errors of less than 3.5 meV/atom, 0.03 eV/Å, and 0.15 GPa for the energy, force, and the stress tensor, respectively, which enable the accurate prediction of physical properties such as lattice constants and the phonon dispersion relationship.
Van Hook, R I
1979-01-01
This report addresses the effects of coal-derived trace and radioactive elements. A summary of our current understanding of health and environmental effects of trace and radioactive elements released during coal mining, cleaning, combustion, and ash disposal is presented. Physical and biological transport phenomena which are important in determining organism exposure are also discussed. Biological concentration and transformation as well as synergistic and antagonistic actions among trace contaminants are discussed in terms of their importance in mobility, persistence, availability, and ultimate toxicity. The consequences of implementing the President's National Energy Plan are considered in terms of the impact of the NEP in 1985 and 2000 on the potential effects of trace and radioactive elements from the coal fuel cycle. Areas of needed research are identified in specific recommendations. PMID:540619
Rasool, Mahmood; Malik, Arif; Basit Ashraf, Muhammad Abdul; Parveen, Gulshan; Iqbal, Shazia; Ali, Irfan; Qazi, Mahmood Husain; Asif, Muhammad; Kamran, Kashif; Iqbal, Asim; Iram, Saima; Khan, Sami Ullah; Mustafa, Mohammad Zahid; Zaheer, Ahmad; Shaikh, Rozeena; Choudhry, Hani; Jamal, Mohammad Sarwar
2016-01-01
Background Ovarian cancer is the 5th most common cause of deaths in the women among gynecological tumors. There are many growing evidences that stress and other behavioral factors may affect cancer progression and patient survival. The purpose of this study is to determine the key role of matrix metalloproteinases (MMPs), and cytokines in the aggregation and progression of ovarian cancer. Methodology Stress variables (MDA, AGEs, AOPPs, NO), profile of antioxidants (SOD, Catalase, Vitamin E & A, GSH, GRx, GPx) and inflammatory biomarkers (MMP-9, MMP-2, MMP-11, IL-1α and TNF-α) were biochemically assessed from venous blood of fifty ovarian cancer patients and twenty healthy control subjects. The results of all parameters were analyzed statistically by independent sample t-test. Results The results of the study demonstrated that the levels of stress variables like MDA (3.38±1.12nmol/ml), AGEs (2.72±0.22 ng/ml), AOPPs (128.48±27.23 ng/ml) and NO (58.71±8.67 ng/ml) were increased in the patients of ovarian cancer as compared to control individuals whereas the profile of antioxidants like SOD, Catalase, Vitamin E, Vitamin A, GSH and GRx were decreased in ovarian cancer patients (0.11±0.08 μg/ml, 2.41±1.01μmol/mol of protein, 0.22±0.04 μg/ml, 45.84±9.07μg/ml, 4.88±1.18μg/ml, 5.33±1.26 μmol/ml respectively). But the level of GPx antioxidant was increased in ovarian cancer patients (6.58±0.21μmol/ml). Moreover the levels of MMP-9 (64.87±5.35 ng/ml), MMP-2 (75.87±18.82 ng/ml) and MMP-11 (63.58±8.48 ng/ml) were elevated in the patients. Similarly, the levels of various cytokines TNF-α and IL-1α were also increased in the patients of ovarian cancer (32.17±3.52 pg/ml and 7.04±0.85 pg/ml respectively). Conclusion MMPs are commonly expressed in ovarian cancer which are potential extrapolative biomarkers and have a major role in metastasis. Due to oxidative stress, different cytokines are released by tumor associated macrophages (TAMs) that result in the
Gebert, Carsten; Brinkschmidt, Christian; Bielack, Stefan; Bernhardt, Thomas; Jürgens, Heribert; Böcker, Werner; Winkelmann, Winfried; Bürger, Horst; Gosheger, Georg
2006-07-01
Matrix-producing bone lesions consist of a wide variety of benign and malignant conditions. With respect to morphology, an overlap exists between benign and malignant bone tumors that causes difficulties in the final determination of the tumor. This study was conducted to show the potential of comparative genomic hybridization as a tool in the differential diagnosis of matrix-producing bone lesions. Thirty benign bone tumors were evaluated by conventional comparative genomic hybridization. To test its diagnostic reliability, 5 additional cases were analyzed, all with differential diagnostic difficulties related to morphology and radiology. All were ultimately diagnosed as malignant sarcomas, and unbalanced alterations were detected. In contrast benign tumors or tumor-like lesions did not reveal any chromosomal alterations. Comparative genomic hybridization is a useful adjunct in the complicated differential diagnostic algorithms of matrix-producing bone tumors.
The use of Ixaru's method in locating the poles of the S-matrix in strictly finite-range potentials
Vertse, Tamas; Lovas, R. G.; Racz, A.; Salamon, P.
2012-09-26
Energies of the S-matrix poles are calculated by solving the radial Schroedinger equation numerically by using Ixaru's CPM(2) method. The trajectories of the poles in the complex wave number plane are determined for two nuclear potentials that are zero beyond finite distances. These are the Woods-Saxon form with cutoff and the Salamon-Vertse potential, which goes to zero smoothly at a finite distance. Properties of the trajectories are analyzed for real and complex values of the depths of the corresponding potentials.
NASA Astrophysics Data System (ADS)
Esfandiari, M.; Shirmardi, S. P.; Medhat, M. E.
2014-06-01
In this study, element analysis and the mass attenuation coefficient for matrixes of gold, bronze and water with various impurities and the concentrations of heavy metals (Cu, Mn, Pb and Zn) are evaluated and calculated by the MCNP simulation code for photons emitted from Barium-133, Americium-241 and sources with energies between 1 and 100 keV. The MCNP data are compared with the experimental data and WinXCom code simulated results by Medhat. The results showed that the obtained results of bronze and gold matrix are in good agreement with the other methods for energies above 40 and 60 keV, respectively. However for water matrixes with various impurities, there is a good agreement between the three methods MCNP, WinXCom and the experimental one in low and high energies.
NASA Astrophysics Data System (ADS)
Garron, Nicolas; Hudspith, Renwick J.; Lytle, Andrew T.
2016-11-01
We compute the hadronic matrix elements of the four-quark operators relevant for {K}^0-{overline{K}}^0 mixing beyond the Standard Model. Our results are from lattice QCD simulations with n f = 2 + 1 flavours of domain-wall fermion, which exhibit continuum-like chiral-flavour symmetry. The simulations are performed at two different values of the lattice spacing ( a ˜ 0 .08 and a ˜ 0 .11 fm) and with lightest unitary pion mass ˜ 300 MeV. For the first time, the full set of relevant four-quark operators is renormalised non-perturbatively through RI-SMOM schemes; a detailed description of the renormalisation procedure is presented in a companion paper. We argue that the intermediate renormalisation scheme is responsible for the discrepancies found by different collaborations. We also study different normalisations and determine the matrix elements of the relevant four-quark operators with a precision of ˜ 5% or better.
Kroeninger, Kevin Alexander; /Bonn U.
2004-04-01
Using a data set of 158 and 169 pb{sup -1} of D0 Run-II data in the electron and muon plus jets channel, respectively, the top quark mass has been measured using the Matrix Element Method. The method and its implementation are described. Its performance is studied in Monte Carlo using ensemble tests and the method is applied to the Moriond 2004 data set.
Gardner, David; Woodward, Carol S.; Evans, Katherine J
2015-01-01
Efficient solution of global climate models requires effectively handling disparate length and time scales. Implicit solution approaches allow time integration of the physical system with a time step dictated by accuracy of the processes of interest rather than by stability governed by the fastest of the time scales present. Implicit approaches, however, require the solution of nonlinear systems within each time step. Usually, a Newton s method is applied for these systems. Each iteration of the Newton s method, in turn, requires the solution of a linear model of the nonlinear system. This model employs the Jacobian of the problem-defining nonlinear residual, but this Jacobian can be costly to form. If a Krylov linear solver is used for the solution of the linear system, the action of the Jacobian matrix on a given vector is required. In the case of spectral element methods, the Jacobian is not calculated but only implemented through matrix-vector products. The matrix-vector multiply can also be approximated by a finite-difference which may show a loss of accuracy in the overall nonlinear solver. In this paper, we review the advantages and disadvantages of finite-difference approximations of these matrix-vector products for climate dynamics within the spectral-element based shallow-water dynamical-core of the Community Atmosphere Model (CAM).
Braem, Caroline; Recolin, Bénédicte; Rancourt, Rebecca C; Angiolini, Christopher; Barthès, Pauline; Branchu, Priscillia; Court, Franck; Cathala, Guy; Ferguson-Smith, Anne C; Forné, Thierry
2008-07-04
We previously showed that genomic imprinting regulates matrix attachment region activities at the mouse Igf2 (insulin-like growth factor 2) locus and that these activities are functionally linked to neighboring differentially methylated regions (DMRs). Here, we investigate the similarly structured Dlk1/Gtl2 imprinted domain and show that in the mouse liver, the G/C-rich intergenic germ line-derived DMR, a sequence involved in domain-wide imprinting, is highly retained within the nuclear matrix fraction exclusively on the methylated paternal copy, reflecting its differential function on that chromosome. Therefore, not only "classical" A/T-rich matrix attachment region (MAR) sequences but also other important regulatory DNA elements (such as DMRs) can be recovered from genomic MAR assays following a high salt treatment. Interestingly, the recovery of one A/T-rich sequence (MAR4) from the "nuclear matrix" fraction is strongly correlated with gene expression. We show that this element possesses an intrinsic activity that favors transcription, and using chromosome conformation capture quantitative real time PCR assays, we demonstrate that the MAR4 interacts with the intergenic germ line-derived DMR specifically on the paternal allele but not with the Dlk1/Gtl2 promoters. Altogether, our findings shed a new light on gene regulation at this locus.
Woodward, Carol S.; Gardner, David J.; Evans, Katherine J.
2015-01-01
Efficient solutions of global climate models require effectively handling disparate length and time scales. Implicit solution approaches allow time integration of the physical system with a step size governed by accuracy of the processes of interest rather than by stability of the fastest time scales present. Implicit approaches, however, require the solution of nonlinear systems within each time step. Usually, a Newton's method is applied to solve these systems. Each iteration of the Newton's method, in turn, requires the solution of a linear model of the nonlinear system. This model employs the Jacobian of the problem-defining nonlinear residual, but thismore » Jacobian can be costly to form. If a Krylov linear solver is used for the solution of the linear system, the action of the Jacobian matrix on a given vector is required. In the case of spectral element methods, the Jacobian is not calculated but only implemented through matrix-vector products. The matrix-vector multiply can also be approximated by a finite difference approximation which may introduce inaccuracy in the overall nonlinear solver. In this paper, we review the advantages and disadvantages of finite difference approximations of these matrix-vector products for climate dynamics within the spectral element shallow water dynamical core of the Community Atmosphere Model.« less
Woodward, Carol S.; Gardner, David J.; Evans, Katherine J.
2015-01-01
Efficient solutions of global climate models require effectively handling disparate length and time scales. Implicit solution approaches allow time integration of the physical system with a step size governed by accuracy of the processes of interest rather than by stability of the fastest time scales present. Implicit approaches, however, require the solution of nonlinear systems within each time step. Usually, a Newton's method is applied to solve these systems. Each iteration of the Newton's method, in turn, requires the solution of a linear model of the nonlinear system. This model employs the Jacobian of the problem-defining nonlinear residual, but this Jacobian can be costly to form. If a Krylov linear solver is used for the solution of the linear system, the action of the Jacobian matrix on a given vector is required. In the case of spectral element methods, the Jacobian is not calculated but only implemented through matrix-vector products. The matrix-vector multiply can also be approximated by a finite difference approximation which may introduce inaccuracy in the overall nonlinear solver. In this paper, we review the advantages and disadvantages of finite difference approximations of these matrix-vector products for climate dynamics within the spectral element shallow water dynamical core of the Community Atmosphere Model.
Schauer, Kevin L; Grosell, Martin
2017-03-15
The regulatory mechanisms behind the production of CaCO3 in the marine teleost intestine are poorly studied despite being essential for osmoregulation and responsible for a conservatively estimated 3-15% of annual oceanic CaCO3 production. It has recently been reported that the intestinally derived precipitates produced by fish as a byproduct of their osmoregulatory strategy form in conjunction with a proteinaceous matrix containing nearly 150 unique proteins. The individual functions of these proteins have not been the subject of investigation until now. Here, organic matrix was extracted from precipitates produced by Gulf toadfish (Opsanus beta) and the matrix proteins were fractionated by their charge using strong anion exchange chromatography. The precipitation regulatory abilities of the individual fractions were then analyzed using a recently developed in vitro calcification assay, and the protein constituents of each fraction were determined by mass spectrometry. The different fractions were found to have differing effects on both the rate of carbonate mineral production, as well as the morphology of the crystals that form. Using data collected from the calcification assay as well as the mass spectrometry experiments, individual calcification promotional indices were calculated for each protein, giving the first insight into the functions each of these matrix proteins may play in regulating precipitation.
Influence of irradiation on the osteoinductive potential of demineralized bone matrix.
Wientroub, S; Reddi, A H
1988-04-01
Samples of demineralized bone matrix (DBM) were exposed to graduated doses of radiation (1-15 Megarad) (Mrad) utilizing a linear accelerator and then implanted into the thoracic region of Long-Evans rats. Subcutaneous implantation of DBM into allogenic rats induces endochondral bone. In response to matrix implantation, a cascade of events ensues; mesenchymal cell proliferation on day 3 postimplantation, chondrogenesis on day 7, calcification of the cartilagenous matrix and chondrolysis on day 9, and osteogenesis on day 11 resulting in formation of an ossicle containing active hemopoietic tissue. Bone formation was assessed by measuring alkaline phosphatase activity, the rate of mineralization was determined by measuring 45Ca incorporation to bone mineral, and 40Ca content measured the extent of mineralization; acid phosphatase activity was used as a parameter for bone resorption. The dose of radiation (2.5 Mrad) currently used by bone banks for sterilization of bone tissue did not destroy the bone induction properties of DBM. Furthermore, radiation of 3-5 Mrad even enhanced bone induction, insofar as it produced more bone at the same interval of time than was obtained from unirradiated control samples. None of the radiation doses used in these experiments abolished bone induction, although the response induced by matrix irradiated with doses higher than 5 Mrad was delayed.
NASA Astrophysics Data System (ADS)
Rienks, E. D. L.; ńrrälä, M.; Lindroos, M.; Roth, F.; Tabis, W.; Yu, G.; Greven, M.; Fink, J.
2014-09-01
We use polarization-dependent angle-resolved photoemission spectroscopy (ARPES) to study the high-energy anomaly (HEA) in the dispersion of Nd2-xCexCuO4, x =0.123. We find that at particular photon energies the anomalous, waterfall-like dispersion gives way to a broad, continuous band. This suggests that the HEA is a matrix element effect: it arises due to a suppression of the intensity of the broadened quasiparticle band in a narrow momentum range. We confirm this interpretation experimentally, by showing that the HEA appears when the matrix element is suppressed deliberately by changing the light polarization. Calculations of the matrix element using atomic wave functions and simulation of the ARPES intensity with one-step model calculations provide further evidence for this scenario. The possibility to detect the full quasiparticle dispersion further allows us to extract the high-energy self-energy function near the center and at the edge of the Brillouin zone.
Potentially toxic elements in foodcrops: Triticum aestivum L., Zea mays L.
NASA Astrophysics Data System (ADS)
Bini, Claudio; Fontana, Silvia; Squizzato, Stefania; Minello, Fabiola; Fornasier, Flavio; Wahsha, Mohammad
2013-04-01
Soil is the basis of the ecosystems and of our system of food production. Crops can uptake heavy metals and potentially toxic elements from the soil and store them in the roots or translocate them to the aerial parts. Excessive content of these elements in edible parts can produce toxic effects and, through the food chain and food consumption, result in a potential hazard for human health. In this study soils and plants (spring wheat, Triticum aestivum L. and maize, Zea mays L.) from a tannery district in North-East Italy were analyzed to determine pedological characters, soil microbial indicators and the content of some major and micro-nutrients and potentially toxic elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, S, Zn, V). The soils of the area are moderately polluted; Cr is the most important inorganic contaminant, followed by Ni, Cu and V. Factor analysis evidenced that the contaminants are in part anthropogenic and in part geogenic. Major anthropogenic origin was detected for Cr, Ni (from industrial activities), Zn, Cu, Cd (from agriculture practices). Biological Absorption Coefficient (BAC) from soil to plant roots and Translocation factor (TF) within the plant were calculated; major nutrients (K, P, S) and some micronutrients (Cu, Zn, Mg, Mn) are easily absorbed and translocated, whilst other nutrients (Ca, Fe) and potentially toxic elements or micronutrients (Al, Cd, Cr, Ni, Pb, V) are not accumulated in the seeds of the two considered species. However, the two edible species proved differently able to absorb and translocate elements, and this suggests to consider separately every species as potential PHEs transporter to the food chain and to humans. Cr concentrations in seeds and other aerial parts (stem and leaves) of the examined plants are higher than the values found for the same species and for other cereals grown on unpolluted soils. Comparing the Cr levels in edible parts with recommended dietary intake, besides other possible Cr sources
NASA Astrophysics Data System (ADS)
Sirait, S. H.; Edison, R. E.; Baidillah, M. R.; Taruno, W. P.; Haryanto, F.
2016-08-01
The aim of this study is to simulate the potential distribution of 2D brain geometry based on two electrodes ECVT. ECVT (electrical capacitance tomography) is a tomography modality which produces dielectric distribution image of a subject from several capacitance electrodes measurements. This study begins by producing the geometry of 2D brain based on MRI image and then setting the boundary conditions on the boundaries of the geometry. The values of boundary conditions follow the potential values used in two electrodes brain ECVT, and for this reason the first boundary is set to 20 volt and 2.5 MHz signal and another boundary is set to ground. Poisson equation is implemented as the governing equation in the 2D brain geometry and finite element method is used to solve the equation. Simulated Hodgkin-Huxley action potential is applied as disturbance potential in the geometry. We divide this study into two which comprises simulation without disturbance potential and simulation with disturbance potential. From this study, each of time dependent potential distributions from non-disturbance and disturbance potential of the 2D brain geometry has been generated.
Kolker, A.; Finkelman, R.B.
1998-01-01
Mode-of-occurrence data are summarized for 13 potentially hazardous elements (Be, Cr, Mn, Co, Ni, As, Se, Cd, Sb, Hg, Pb, Th, U) in coal. Recent work has refined mode-of-occurrence data for Ni, Cr, and As, as compared to previous summaries. For Cr, dominant modes of occurrence include the clay mineral illite, an amorphous CrO(OH) phase, and Cr-bearing spinels. Nickel is present in Fe-sulfides (pyrite and marcasite) and is also organically bound. Arsenic-bearing pyrite may be the dominant host of As in bituminous coals. Concentration data for the 13 HAPs, obtained primarily by quantitative microanalysis techniques, are compiled for mineral and organic portions of coal. HAPs element concentrations are greatest in Fe-sulfides, and include maxima of 2,300 ppm (Co), 4,500 ppm (Ni), 4.9wt.% (As), 2,000 ppm (Se), 171 ppm (Hg), and 5,500 ppm (Pb). Trace-element microanalysis is a significant refinement over bulk methods, and shows that there is considerable trace-element variation on a fine scale for a given coal, and from one coal to another. ?? 1998 OPA (Overseas Publishers Association) N.V. Published by license under the Gordon and Breach Science Publishers imprint.
Akhbarizadeh, Razegheh; Moore, Farid; Keshavarzi, Behnam; Moeinpour, Alireza
2017-01-01
Marine pollutants are becoming a growing concern due to their ecological consequences. This study investigates the potential risk posed by microplastics and toxic elements in coastal sediments of Khark Island, the main oil export hub of Iran. Principal component biplots exhibited a significant positive correlation between microplastic quantities (ranging in shape and color) and concentration of heavy metals with industrial activity. Source identification of the heavy metals indicated both natural and anthropogenic origin. Quality and risk assessment of the sediments revealed low to moderate pollution of Zn, Mo, Pb, Cu, Cd and As in some stations. Results of metal fractionation in sediments demonstrated that Cd, Mn, Zn, As and Pb are capable of posing a serious ecological risk due to potential bioavailability. Microplastics, mostly fragments and fibers, were detected in all sediment samples (ranging from 59 to 217 items/200 g dry sediment). A relatively good significant linear relationship exists between microplastic quantities and potentially toxic element/polycyclic aromatic hydrocarbon concentrations in coastal sediments. The results of this study confirmed the key role of microplastics as a "potential contaminant vector" for other types of pollutants.
Wan, Dejun; Zhan, Changlin; Yang, Guanglin; Liu, Xingqi; Yang, Jinsong
2016-01-01
To examine levels, health risks, sources, and spatial distributions of potentially toxic elements in settled dust over Beijing urban area, 62 samples were collected mostly from residential building outdoor surfaces, and their <63 μm fractions were measured for 12 potentially toxic elements. The results show that V, Cr, Mn, Co, Ni, and Ba in dust are from predominantly natural sources, whereas Cu, Zn, As, Cd, Sb, and Pb mostly originate from anthropogenic sources. Exposure to these elements in dust has significant non-cancer risks to children but insignificant to adults. Cancer risks of Cr, Co, Ni, As, and Cd via inhalation and dermal contact are below the threshold of 10−6–10−4 but As via dust ingestion shows a tolerable risk. The non-cancer risks to children are contributed mainly (75%) by As, Pb, and Sb, and dominantly (92%) via dust ingestion, with relatively higher risks mainly occurring in the eastern and northeastern Beijing urban areas. Although Cd, Zn, and Cu in dust are heavily affected by anthropogenic sources, their health risks are insignificant. Source appointments suggest that coal burning emissions, the dominant source of As, are likely the largest contributors to the health risk, and traffic-related and industrial emissions are also important because they contribute most of the Pb and Sb in dust. PMID:27187427
NASA Technical Reports Server (NTRS)
Chen, T.; Raju, I. S.
2002-01-01
A coupled finite element (FE) method and meshless local Petrov-Galerkin (MLPG) method for analyzing two-dimensional potential problems is presented in this paper. The analysis domain is subdivided into two regions, a finite element (FE) region and a meshless (MM) region. A single weighted residual form is written for the entire domain. Independent trial and test functions are assumed in the FE and MM regions. A transition region is created between the two regions. The transition region blends the trial and test functions of the FE and MM regions. The trial function blending is achieved using a technique similar to the 'Coons patch' method that is widely used in computer-aided geometric design. The test function blending is achieved by using either FE or MM test functions on the nodes in the transition element. The technique was evaluated by applying the coupled method to two potential problems governed by the Poisson equation. The coupled method passed all the patch test problems and gave accurate solutions for the problems studied.
Potentially-toxic and essential elements profile of AH1N1 patients in Mexico City
Moya, Mireya; Bautista, Edgar G.; Velázquez-González, Antonio; Vázquez-Gutiérrez, Felipe; Tzintzun, Guadalupe; García-Arreola, María Elena; Castillejos, Manuel; Hernández, Andrés
2013-01-01
During spring of 2009, a new influenza virus AH1N1 spread in the world causing acute respiratory illness and death, resulting in the first influenza pandemic since 1968. Blood levels of potentially-toxic and essential elements of 40 pneumonia and confirmed AH1N1 were evaluated against two different groups of controls, both not infected with the pandemic strain. Significant concentrations of potentially-toxic elements (lead, mercury, cadmium, chromium, arsenic) along with deficiency of selenium or increased Zn/Cu ratios characterized AH1N1 cases under study when evaluated versus controlled cases. Deficiency of selenium is progressively observed from controls I (influenza like illness) through controls II (pneumonia) and finally pneumonia -AH1N1 infected patients. Cases with blood Se levels greater than the recommended for an optimal cut-off to activate glutathione peroxidase (12.5 μg/dL) recovered from illness and survived. Evaluation of this essential element in critical pneumonia patients at the National Institutes is under evaluation as a clinical trial. PMID:23422930
Study of road dust magnetic phases as the main carrier of potentially harmful trace elements.
Bourliva, Anna; Papadopoulou, Lambrini; Aidona, Elina
2016-05-15
Mineralogical and morphological characteristics and heavy metal content of different fractions (bulk, non-magnetic fraction-NMF and magnetic fraction-MF) of road dusts from the city of Thessaloniki (Northern Greece) were investigated. Main emphasis was given on the magnetic phases extracted from these dusts. High magnetic susceptibility values were presented, whereas the MFs content of road dust samples ranged in 2.2-14.7 wt.%. Thermomagnetic analyses indicated that the dominating magnetic carrier in all road dust samples was magnetite, while the presence of hematite and iron sulphides in the investigated samples cannot be excluded. SEM/EDX analyses identified two groups of ferrimagnetic particles: spherules with various surface morphologies and textures and angular/aggregate particles with elevated heavy metal contents, especially Cr. The road dusts (bulk samples) were dominated by calcium, while the mean concentrations of trace elements decreased in the order Zn > Mn > Cu > Pb > Cr > Ni > V > Sn > As > Sb > Co > Mo > W > Cd. MFs exhibited significantly higher concentrations of trace elements compared to NMFs indicating that these potentially harmful elements (PHEs) are preferentially enriched in the MFs and highly associated with the ferrimagnetic particles. Hazard Index (HI) obtained for both adults and children through exposure to bulk dust samples were lower or close to the safe level (=1). On the contrary, the HIs for the magnetic phases indicated that both children and adults are experiencing potential health risk since HI for Cr was significantly higher than safe level. Cancer risk due to road dust exposure is low.
NASA Astrophysics Data System (ADS)
Kostensalo, Joel; Suhonen, Jouni
2017-01-01
Half-lives for 148 potentially measurable 2nd-, 3rd-, 4th-, 5th-, 6th-, and 7th-forbidden unique beta transitions are predicted. To achieve this, the ratio of the nuclear matrix elements (NMEs), calculated by the proton-neutron quasiparticle random-phase approximation (pnQRPA), MpnQRPA, and a two-quasiparticle (two-qp) model, Mqp, is studied and compared with earlier calculations for the allowed Gamow-Teller (GT) 1+ and first-forbidden spin-dipole (SD) 2- transitions. The present calculations are done using realistic single-particle model spaces and G -matrix based microscopic two-body interactions. In terms of the ratio k =MpnQRPA/Mqp the studied decays fall into two groups: for GROUP 1, which consists of transitions involving non-magic nuclei, the ratio turns out to be k =0.29 ±0.15 . For GROUP 2, consisting of transitions involving semimagic nuclei, the ratio is 0.5-0.8 for half of the decays and less than 5 ×10-3 for the other half. The magnitudes of the NMEs for several nuclei of GROUP 2 depend sensitively on the size of the used single-particle space and the energies of few key single-particle orbitals used in the pnQRPA calculation, while no such dependence is found for the transitions involving nuclei of GROUP 1. Comparing the NME ratios k of GROUP 1 with those of the earlier GT and SD calculations, where also experimental data are available, the expected "experimental" half-lives for the decays between the 0+ ground state of the even-even reference nuclei and the Jπ=3+,4-,5+,6-,7+,8- states of the neighboring odd-odd nuclei are derived for possible experimental verification. The present results could also shed light to the magnitudes of the NMEs corresponding to the high-forbidden unique 0+→Jπ=3+,4-,5+,6-,7+,8- virtual transitions taking part in the neutrinoless double beta decays.
Leaves of Phragmites australis as potential atmospheric biomonitors of Platinum Group Elements.
Bonanno, Giuseppe; Pavone, Pietro
2015-04-01
The increasing emissions of Platinum Group Elements (PGEs), namely Pt, Pd and Rh, may pose a significant risk to ecosystem processes and human health. A periodic assessment of PGEs distribution in the environment is thus of the utmost importance for the implementation of timely measures of mitigation. Although several studies have quantified PGEs in different life forms such as mammals, birds, fish, crustaceans, algae, mosses and even human beings, data about vascular plants need further surveys. This study aimed to test the suitability of the grass Phragmites australis (common reed) as a biomonitor of PGEs atmospheric pollution. The results showed that Pd and Pt concentrations in leaves are significantly higher in urban areas. In particular, Pd showed the highest range of values in line with current studies that consider palladium as the main element of traffic-related pollution. Overall, the leaves of Phragmites australis reflected the different gradient of PGEs emissions, and may thus be considered as potential biomonitors of atmospheric pollution.
Akemann, G; Bloch, J; Shifrin, L; Wettig, T
2008-01-25
We analyze how individual eigenvalues of the QCD Dirac operator at nonzero quark chemical potential are distributed in the complex plane. Exact and approximate analytical results for both quenched and unquenched distributions are derived from non-Hermitian random matrix theory. When comparing these to quenched lattice QCD spectra close to the origin, excellent agreement is found for zero and nonzero topology at several values of the quark chemical potential. Our analytical results are also applicable to other physical systems in the same symmetry class.
Bo, Iselin M. Th.; Esser, Ruth; Lie-Svendsen, Oystein E-mail: ruth.esser@uit.no
2013-05-20
We model the effect of gravitational settling in the upper chromosphere on O, Fe, Si, and Ne, studying whether Coulomb collisions between ionized low First Ionization Potential (FIP) elements and protons is sufficient to cause abundance enhancements relative to oxygen. We find that low-FIP abundance enhancements comparable to observed values can be obtained provided the hydrogen ionization degree lies in the approximate range 10%-30%, which agrees with chromospheric models. Lower or higher hydrogen ionization causes the FIP-effect to become smaller or absent (depletion of all heavy elements). Iron must be almost fully ionized in order to become enriched relative to high-FIP elements, and this requires a high iron photoionization rate. The time scale necessary to produce the enrichment increases rapidly with increasing H ionization. For iron in a background from a semiempirical chromospheric model, with an H ion fraction of the order of 30%-40% in the upper chromosphere, 1-2 hr of settling is required to produce enhancements comparable to observations. The absolute abundance (relative to H), which monotonically decreases with time during settling, has by that time decreased by less than 50% in the same altitude region. With the same background conditions, the silicon abundance is more strongly enhanced by the settling than the iron abundance. The high-FIP element neon is depleted, relative to O and low-FIP elements, in the same background and altitude region where iron is enhanced, typically by 50% or more relative to O after 1-2 hr of settling.
Minor and potentially toxic trace elements in milk and blood serum of dairy donkeys.
Fantuz, F; Ferraro, S; Todini, L; Piloni, R; Mariani, P; Malissiova, E; Salimei, E
2015-08-01
Cs. In the current experimental conditions, in agreement with the low levels in drinking water and feedstuff, donkey milk concentration of potentially toxic elements was very low and did not raise health concerns for human consumption.
Broaders, Eileen; Gahan, Cormac G M; Marchesi, Julian R
2013-01-01
The human intestine is an important location for horizontal gene transfer (HGT) due to the presence of a densely populated community of microorganisms which are essential to the health of the human superorganism. HGT in this niche has the potential to influence the evolution of members of this microbial community and to mediate the spread of antibiotic resistance genes from commensal organisms to potential pathogens. Recent culture-independent techniques and metagenomic studies have provided an insight into the distribution of mobile genetic elements (MGEs) and the extent of HGT in the human gastrointestinal tract. In this mini-review, we explore the current knowledge of mobile genetic elements in the gastrointestinal tract, the progress of research into the distribution of antibiotic resistance genes in the gut and the potential role of MGEs in the spread of antibiotic resistance. In the face of reduced treatment options for many clinical infections, understanding environmental and commensal antibiotic resistance and spread is critical to the future development of meaningful and long lasting anti-microbial therapies.
Haefner, Petra
2008-07-31
The top quark plays a special role in the Standard Model of Particle Physics. With its enormous mass of about 170 GeV it is as heavy as a gold atom and is the only quark with a mass near the electroweak scale. Together with theW boson mass, the top quark mass allows indirect constraints on the mass of the hypothetical Higgs boson, which might hold the clue to the origin of mass. Top pair production with a semileptonic decay t $\\bar{t}$ →W^{±}W^{∓} b$\\bar{b}$ →q $\\bar{t}$lnb$\\bar{b}$ is the ”golden channel” for mass measurements, due to a large branching fraction and a relatively low background contamination compared to other decay channels. Top mass measurements based on this decay, performed with the matrix element method, have always been among the single best measurements in the world. In 2007, the top mass world average broke the 1% level of precision. Its measurement is no longer dominated by statistical but instead by systematic uncertainties. The reduction of systematic uncertainties has therefore become a key issue for further progress. This thesis introduces two new developments in the treatment of b jets. The first improvement is an optimization in the way b identification information is used. It leads to an enhanced separation between signal and background processes and reduces the statistical uncertainty by about 16%. The second improvement determines differences in the detector response and thus the energy scales of light jets and b jets. Thereby, it addresses the major source of systematic uncertainty in the latest top mass measurements. The method was validated on Monte Carlo events at the generator level, calibrated with fully simulated events, including detector simulation, and applied to D0 Run II data corresponding to 1 fb^{-1} of integrated luminosity. Possible sources of systematic uncertainties were studied. The top mass is measured to be: m_{t} = (169.2±3.5(stat.)±1.0(syst.)) GeV . The
NASA Astrophysics Data System (ADS)
Pražnikar, Jure; Cepak, Franka; Žibert, Janez
2014-09-01
In the presented study a comprehensive statistical analysis of the chemical composition of atmospheric particulate matter was carried out. The data were collected from April 2003 to August 2008 with a 7-day time resolution in the Northern Adriatic Port of Koper and analyzed by the Proton Induced X-ray method (PIXE). The Positive Matrix Factorization (PMF) analysis of fifteen chemical elements identified six source factors, three natural-regional sources and three local-anthropogenic sources. Heavy machinery, industry and iron ore factor were marked as anthropogenic sources. Heavy machinery source was represented by the elements V, Ni and Cu. The elements Fe and Mn are attributed to the Iron ore source and were explained by the proximity of the bulk-cargo warehouse and the intense handling of iron ore in Port of Koper. The heavy industry source represented by Pb and Zn was the only anthropogenic factor, which shows clear seasonal pattern. In contrast to the local-anthropogenic source factors, natural and regional source factors show significant negative trend. The reduction of the crustal elements Ca, Ti and Sr, joined in a soil source, and sulfur-biomass source, represented by elements K and S, have been attributed to more intense precipitation and to the negative trend of the North Atlantic Oscillation (NAO) index. The negative trend of the Cl and Br elements was in line with the negative trend of the wind speed above the sea surface and the significant sea-wave height.
Kim, Min Jung; Lee, Jihye; Kim, Seon Hee; Kim, Haidong; Lee, Kang-Bong; Lee, Yeonhee
2015-10-01
Chalcopyrite Cu(In, Ga)Se2 (CIGS) thin films are well known as the next-generation solar cell materials notable for their high absorption coefficient for solar radiation, suitable band gap, and ability for deposition on flexible substrate materials, allowing the production of highly flexible and lightweight solar panels. To improve solar cell performances, a quantitative and depth-resolved elemental analysis of photovoltaic thin films is much needed. In this study, Cu(In, Ga)Se2 thin films were prepared on molybdenum back contacts deposited on soda-lime glass substrates via three-stage evaporation. Surface analyses via AES and SIMS were used to characterize the CIGS thin films and compare their depth profiles. We determined the average concentration of the matrix elements, Cu, In, Ga, and Se, using ICP-AES, XRF, and EPMA. We also obtained depth profiling results using TOF-SIMS, magnetic sector SIMS and AES, and APT, a sub-nanometer resolution characterization technique that enables three-dimensional elemental mapping. The SIMS technique, with its high detection limit and ability to obtain the profiles of elements in parallel, is a powerful tool for monitoring trace elements in CIGS thin films. To identify impurities in a CIGS layer, the distribution of trace elements was also observed according to depth by SIMS and APT.
Cabral Pinto, Marina M S; Marinho-Reis, A Paula; Almeida, Agostinho; Ordens, Carlos M; Silva, Maria M V G; Freitas, Sandra; Simões, Mário R; Moreira, Paula I; Dinis, Pedro A; Diniz, M Luísa; Ferreira da Silva, Eduardo A; Condesso de Melo, M Teresa
2017-03-09
New lines of evidence suggest that less than 10% of neurodegenerative diseases have a strict genetic aetiology and other factors may be prevalent. Environmental exposures to potentially toxic elements appear to be a risk factor for Parkinson's, Alzheimer's and sclerosis diseases. This study proposes a multidisciplinary approach combining neurosciences, psychology and environmental sciences while integrating socio-economic, neuropsychological, environmental and health data. We present the preliminary results of a neuropsychological assessment carried out in elderly residents of the industrial city of Estarreja. A battery of cognitive tests and a personal questionnaire were administered to the participants. Multivariate analysis and multiple linear regression analysis were used to identify potential relationships between the cognitive status of the participants and environmental exposure to potentially toxic elements. The results suggest a relationship between urinary PTEs levels and the incidence of cognitive disorders. They also point towards water consumption habits and profession as relevant factors of exposure. Linear regression models show that aluminium (R (2) = 38%), cadmium (R (2) = 11%) and zinc (R (2) = 6%) are good predictors of the scores of the Mini-Mental State Examination cognitive test. Median contents (µg/l) in groundwater are above admissible levels for drinking water for aluminium (371), iron (860), manganese (250), and zinc (305). While the World Health Organization does not provide health-based reference values for aluminium, results obtained from this study suggest that it may have an important role in the cognitive status of the elderly. Urine proved to be a suitable biomarker of exposure both to elements with low and high excretion rates.
NASA Astrophysics Data System (ADS)
Gao, Huizhong; Liang, Lin; Chen, Xiaoguang; Xu, Guanghua
2015-01-01
Due to the non-stationary characteristics of vibration signals acquired from rolling element bearing fault, the time-frequency analysis is often applied to describe the local information of these unstable signals smartly. However, it is difficult to classify the high dimensional feature matrix directly because of too large dimensions for many classifiers. This paper combines the concepts of time-frequency distribution(TFD) with non-negative matrix factorization(NMF), and proposes a novel TFD matrix factorization method to enhance representation and identification of bearing fault. Throughout this method, the TFD of a vibration signal is firstly accomplished to describe the localized faults with short-time Fourier transform(STFT). Then, the supervised NMF mapping is adopted to extract the fault features from TFD. Meanwhile, the fault samples can be clustered and recognized automatically by using the clustering property of NMF. The proposed method takes advantages of the NMF in the parts-based representation and the adaptive clustering. The localized fault features of interest can be extracted as well. To evaluate the performance of the proposed method, the 9 kinds of the bearing fault on a test bench is performed. The proposed method can effectively identify the fault severity and different fault types. Moreover, in comparison with the artificial neural network(ANN), NMF yields 99.3% mean accuracy which is much superior to ANN. This research presents a simple and practical resolution for the fault diagnosis problem of rolling element bearing in high dimensional feature space.
Foley, J.; Ley, C.A.; Parysek, L.M.
1994-07-15
The authors determined the complete nucleotide sequence of the coding region of the human peripherin gene (PRPH), as well as 742 bp 5{prime} to the cap site and 584 bp 3{prime} to the stop codon, and compared its structure and sequence to the rat and mouse genes. The overall structure of 9 exons separated by 8 introns is conserved among these three mammalian species. The nucleotide sequences of the human peripherin gene exons were 90% identical to the rat gene sequences, and the predicted human peripherin protein differed from rat peripherin at only 18 of 475 amino acid residues. Comparison of the 5{prime} flanking regions of the human peripherin gene and rodent genes revealed extensive areas of high homology. Additional conserved segments were found in introns 1 and 2. Within the 5{prime} region, potential regulatory sequences, including a nerve growth factor negative regulatory element, a Hox protein binding site, and a heat shock element, were identified in all peripherin genes. The positional conservation of each element suggests that they may be important in the tissue-specific, developmental-specific, and injury-specific expression of the peripherin gene. 24 refs., 2 figs., 1 tab.
Aschner, Yael; Zemans, Rachel L; Yamashita, Cory M; Downey, Gregory P
2014-10-01
Acute lung injury (ALI) and ARDS fall within a spectrum of pulmonary disease that is characterized by hypoxemia, noncardiogenic pulmonary edema, and dysregulated and excessive inflammation. While mortality rates have improved with the advent of specialized ICUs and lung protective mechanical ventilation strategies, few other therapies have proven effective in the management of ARDS, which remains a significant clinical problem. Further development of biomarkers of disease severity, response to therapy, and prognosis is urgently needed. Several novel pathways have been identified and studied with respect to the pathogenesis of ALI and ARDS that show promise in bridging some of these gaps. This review will focus on the roles of matrix metalloproteinases and protein tyrosine kinases in the pathobiology of ALI in humans, and in animal models and in vitro studies. These molecules can act independently, as well as coordinately, in a feed-forward manner via activation of tyrosine kinase-regulated pathways that are pivotal in the development of ARDS. Specific signaling events involving proteolytic processing by matrix metalloproteinases that contribute to ALI, including cytokine and chemokine activation and release, neutrophil recruitment, transmigration and activation, and disruption of the intact alveolar-capillary barrier, will be explored in the context of these novel molecular pathways.
Duellman, Tyler; Burnett, John; Shin, Alice; Yang, Jay
2015-08-28
Matrix metalloproteinase-9 (MMP-9) is a secreted glycoprotein with a major role in shaping the extracellular matrix and a detailed understanding of the secretory mechanism could help identify methods to correct diseases resulting from dysregulation of secretion. MMP-9 appears to follow a canonical secretory pathway through a quality control cycle in the endoplasmic reticulum (ER) before transport of the properly folded protein to the Golgi apparatus and beyond for secretion. Through a complementation assay, we determined that LMAN1, a well-studied lectin-carrier protein, interacts with a secretion-competent N-glycosylated MMP-9 in the ER while N-glycosylation-deficient secretion-compromised MMP-9 does not. In contrast, co-immunoprecipitation demonstrated protein interaction between LMAN1 and secretion-compromised N-glycosylation-deficient MMP-9. MMP-9 secretion was reduced in the LMAN1 knockout cell line compared to control cells confirming the functional role of LMAN1. These observations support the role of LMAN1 as a lectin-carrier protein mediating efficient MMP-9 secretion.
Katz, Jordan M; Nataraj, Chandra; Jaw, Rebecca; Deigl, Elizabeth; Bursac, Predrag
2009-04-01
The osteoinductivity of demineralized bone matrix (DBM) varies from donor to donor as a result of varying levels of multiple growth factors, matrix integrity, and artifacts from material processing. Many in vitro assays are currently used for screening the osteoinductivity of DBM. The objectives of this study were to determine the correlation of specific growth factors and in vitro mitotic stimulation to in vivo ectopic bone formation capacity with a large number of DBM samples. Samples were assayed using ELISA methods for BMP-2/4 and TGF-beta1 (n = 304) and cell proliferation using SAOS-2 osteoblasts (n = 239). All samples were then implanted intramuscularly in the abdomen of nude rats. All in vitro assays showed significant variability for any particular level of ostoinductivity determined by in vivo model. A significant, but only very weak, positive correlation to in vivo results was found for TGF-beta1 (r(2) = 0.016), BMP 2/4 (r(2) = 0.065), and SAOS-2 cell proliferation (r(2) = 0.053). The results of this study amplify the notion that a multitude of factors and their relative interplay, rather than a single factor are likely to determine the potency of any particular lot of DBM.
Duellman, Tyler; Burnett, John; Shin, Alice; Yang, Jay
2015-01-01
Matrix metalloproteinase-9 (MMP-9) is a secreted glycoprotein with a major role in shaping the extra-cellular matrix and a detailed understanding of the secretory mechanism could help identify methods to correct diseases resulting from dysregulation of secretion. MMP-9 appears to follow a canonical secretory pathway through a quality control cycle in the endoplasmic reticulum (ER) before transport of the properly folded protein to the Golgi apparatus and beyond for secretion. Through a complementation assay, we determined that LMAN1, a well-studied lectin-carrier protein, interacts with a secretion-competent N-glycosylated MMP-9 in the ER while N-glycosylation-deficient secretion-compromised MMP-9 does not. In contrast, co-immunoprecipitation demonstrated protein interaction between LMAN1 and secretion-compromised N-glycosylation-deficient MMP-9. MMP-9 secretion was reduced in the LMAN1 knockout cell line compared to control cells confirming the functional role of LMAN1. These observations support the role of LMAN1 as a lectin-carrier protein mediating efficient MMP-9 secretion. PMID:26150355
NASA Astrophysics Data System (ADS)
Amory, V.; Lhémery, A.
2008-02-01
Inspection of irregular components is problematical: maladjustment of transducer shoes to surfaces causes aberrations. Flexible phased-arrays (FPAs) designed at CEA LIST to maximize contact are driven by adapted delay laws to compensate for irregularities. Optimizing FPA requires simulation tools. The behavior of one element computed by FEM is observed at the surface and its radiation experimentally validated. Efforts for one element prevent from simulating a FPA by FEM. A model is proposed where each element behaves as nonuniform source of stresses. Exact and asymptotic formulas for Lamb problem are used as convolution kernels for longitudinal, transverse and head waves; the latter is of primary importance for angle-T-beam inspections.
Pérez-Sirvent, Carmen; Martínez-Sánchez, Maria José; López, Salvadora Martínez; Del Carmen Gómez Martínez, Maria; Guardiola, Francisco A; Esteban, María Ángeles
2016-11-01
Fish are an important source of nutrients in human nutrition. Although arsenic (As) is considered potentially carcinogenic for human being, very little is known about its toxicity in fish biology. To increase our knowledge of the effect of exposure to waterborne As on fish, gilthead seabream (Sparus aurata) were exposed to 5 μM As2O3 and the bioaccumulation of macronutrients (Ca, K, Mg, Na, P), micronutrients (Fe, Mn, Zn) and Potentially Harmful Elements (As, Cd) was determined using spectrometric techniques. All elements were determined in the muscle and liver of non-exposed fish and those exposed to As for 2, 10 or 30 days. The concentrations of K, Na, Mg, Mn and Zn (in muscle) and Fe and Mn (in liver) of control (non-exposed) fish were higher than those determined in exposed fish. Furthermore, neither As nor Cd accumulated in the edible part (muscle) of seabream and were only evident in liver after 30 days of continuous exposure to As, but both concentrations remained below legally established limits.
Osypov, Alexander A; Krutinin, Gleb G; Krutinina, Eugenia A; Kamzolova, Svetlana G
2012-04-01
Electrostatic properties of genome DNA are important to its interactions with different proteins, in particular, related to transcription. DEPPDB - DNA Electrostatic Potential (and other Physical) Properties Database - provides information on the electrostatic and other physical properties of genome DNA combined with its sequence and annotation of biological and structural properties of genomes and their elements. Genomes are organized on taxonomical basis, supporting comparative and evolutionary studies. Currently, DEPPDB contains all completely sequenced bacterial, viral, mitochondrial, and plastids genomes according to the NCBI RefSeq, and some model eukaryotic genomes. Data for promoters, regulation sites, binding proteins, etc., are incorporated from established DBs and literature. The database is complemented by analytical tools. User sequences calculations are available. Case studies discovered electrostatics complementing DNA bending in E.coli plasmid BNT2 promoter functioning, possibly affecting host-environment metabolic switch. Transcription factors binding sites gravitate to high potential regions, confirming the electrostatics universal importance in protein-DNA interactions beyond the classical promoter-RNA polymerase recognition and regulation. Other genome elements, such as terminators, also show electrostatic peculiarities. Most intriguing are gene starts, exhibiting taxonomic correlations. The necessity of the genome electrostatic properties studies is discussed.
Extracellular matrix and cell shape: potential control points for inhibition of angiogenesis
NASA Technical Reports Server (NTRS)
Ingber, D.
1991-01-01
Capillary endothelial (CE) cells require two extracellular signals in order to switch from quiescence to growth and back to differentiation during angiogenesis: soluble angiogenic factors and insoluble extracellular matrix (ECM) molecules. Soluble endothelial mitogens, such as basic fibroblast growth factor (FGF), act over large distances to trigger capillary growth, whereas ECM molecules act locally to modulate cell responsiveness to these soluble cues. Recent studies reveal that ECM molecules regulate CE cell growth and differentiation by modulating cell shape and by activating intracellular chemical signaling pathways inside the cell. Recognition of the importance of ECM and cell shape during capillary morphogenesis has led to the identification of a series of new angiogenesis inhibitors. Elucidation of the molecular mechanism of capillary regulation may result in development of even more potent angiogenesis modulators in the future.
Matrix Metalloproteinases as Potential Targets in the Venous Dilation Associated with Varicose Veins
Kucukguven, Arda; Khalil, Raouf A.
2013-01-01
Varicose veins (VVs) are a common venous disease of the lower extremity characterized by incompetent valves, venous reflux, and dilated and tortuous veins. If untreated, VVs could lead to venous thrombosis, thrombophlebitis and chronic venous leg ulcers. Various genetic, hormonal and environmental factors may lead to structural changes in the vein valves and make them incompetent, leading to venous reflux, increased venous pressure and vein wall dilation. Prolonged increases in venous pressure and vein wall tension are thought to increase the expression/activity of matrix metalloproteinases (MMPs). Members of the MMPs family include collagenases, gelatinases, stromelysins, matrilysins, membrane-type MMPs and others. MMPs are known to degrade various components of the extracellular matrix (ECM). MMPs may also affect the endothelium and vascular smooth muscle, causing changes in the vein relaxation and contraction mechanisms. ECs injury also triggers leukocyte infiltration, activation and inflammation, which lead to further vein wall damage. The vein wall dilation and valve dysfunction, and the MMP activation and superimposed inflammation and fibrosis would lead to progressive venous dilation and VVs formation. Surgical ablation is an effective treatment for VVs, but may be associated with high recurrence rate, and other less invasive approaches that target the cause of the disease are needed. MMP inhibitors including endogenous tissue inhibitors (TIMPs) and pharmacological inhibitors such as zinc chelators, doxycycline, batimastat and marimastat, have been used as diagnostic and therapeutic tools in cancer, autoimmune and cardiovascular disease. However, MMP inhibitors may have side effects especially on the musculoskeletal system. With the advent of new genetic and pharmacological tools, specific MMP inhibitors with fewer undesirable effects could be useful to retard the progression and prevent the recurrence of VVs. PMID:23316963
Lishev, St.; Yordanov, D. Shivarova, A.
2015-04-08
Concepts for the extraction of volume-produced negative hydrogen ions from a rf matrix source (a matrix of small-radius discharges with a planar-coil inductive driving) are presented and discussed based on experimental results for the current densities of the extracted ions and the co-extracted electrons. The experiment has been carried out in a single discharge of the source: a rf discharge with a radius of 2.25 cm inductively driven by a 3.5-turn planar coil. The length of the discharge tube, the area of the reference electrode inserted in the discharge volume, the discharge modes, the magnetic filter and its position along the discharge length, the position of the permanent magnets for the separation of the co-extracted electrons from the extracted ions in the extraction device and the bias applied to its first electrode are considered as factors influencing the extracted currents of negative ions.
Civitarese, Osvaldo; Suhonen, Jouni
2013-12-30
In this work we report on general properties of the nuclear matrix elements involved in the neutrinoless double β{sup −} decays (0νβ{sup −}β{sup −} decays) of several nuclei. A summary of the values of the NMEs calculated along the years by the Jyväskylä-La Plata collaboration is presented. These NMEs, calculated in the framework of the quasiparticle random phase approximation (QRPA), are compared with those of the other available calculations, like the Shell Model (ISM) and the interacting boson model (IBA-2)
Bes, D. R.; Civitarese, O.
2010-01-15
Theoretical matrix elements, for the ground-state to ground-state two-neutrino double-{beta}-decay mode (2{nu}{beta}{sup -}{beta}{sup -}gs->gs) of {sup 128,130}Te isotopes, are calculated within a formalism that describes interactions between neutrons in a superfluid phase and protons in a normal phase. The elementary degrees of freedom of the model are proton-pair modes and pairs of protons and quasineutrons. The calculation is basically a parameter-free one, because all relevant parameters are fixed from the phenomenology. A comparison with the available experimental data is presented.
Schwenke, David W.
2015-04-14
In this work, we systematically derive the matrix elements of the nuclear rotation operators for open shell diatomic and polyatomic molecules in a parity adapted Hund’s case (a) basis. Our expressions are valid for an arbitrary number of electrons and arbitrary electronic configurations. The common ad hoc sign changes of angular momentum operators are shown to be equivalent to a change in phase of basis functions. We show how to relate this basis to that required for scattering calculations. We also give the expressions for Einstein A coefficients for electric dipole, electric quadrupole, and magnetic dipole transitions.
Technology Transfer Automated Retrieval System (TEKTRAN)
Blueberry is adapted to acidic soil conditions but is often planted in high pH soils by adding elemental sulfur (S) prior to planting. Two pot experiments were carried out in a glasshouse to determine the potential of applying elemental S by fertigation through a drip irrigation system. In the first...
Mauney, Joshua R; Kaplan, David L; Volloch, Vladimir
2004-07-01
During prolonged cultivation ex vivo, adult bone marrow stromal stem cells (BMSCs) undergo two probably interdependent processes, replicative aging and a decline in differentiation potential. Recently, our results with primary human fibroblasts indicated that growth on denatured collagen (DC) matrix results in the reduction of the rate of cellular aging. The present study has been undertaken to test whether the growth of human BMSCs under the same conditions would translate into preservation of cellular aging-attenuated functions, such as the ability to express HSP70 in response to stress as well as of osteogenic differentiation potential. We report here that growth of BMSCs on a DC matrix versus tissue culture polystyrene significantly reduced one of the main manifestations of cellular aging, the attenuation of the ability to express a major protective stress response component, HSP70, increased the proliferation capacity of ex vivo expanded BMSCs, reduced the rate of morphological changes, and resulted in a dramatic increase in the retention of the potential to express osteogenic-specific functions and markers upon treatment with osteogenic stimulants. BMSCs are a promising and increasingly important cell source for tissue engineering as well as cell and gene therapeutic strategies. For use of BMSCs in these applications, ex vivo expansion is necessary to obtain a sufficient, therapeutically useful, number of cells; however, this results in the loss of differentiation potential. This problem is especially acute in older patients where more extensive in vitro expansion of smaller number of stem/progenitor cells is needed. The finding that growth on certain biomaterials preserves aging-attenuated functions, enhances proliferation capacity, and maintains differentiation potential of BMSCs indicates a promising approach to address this problem.
Glushkov, A. V.; Khetselius, O.; Gurnitskaya, E.; Loboda, A.; Mischenko, E.
2009-03-09
New relativistic approach, based on the gauge-invariant perturbation theory (PT) with using the optimized wave functions basis's, is applied to calculating the inter atomic potentials, hyper fine structure (hfs) collision shift for alkali atoms in atmosphere of inert gases. Data for inter atomic potentials, collision shifts of the Rb and Cs atoms in atmosphere of the inert gas He are presented.
A potential role for glia-derived extracellular matrix remodeling in postinjury epilepsy.
Kim, Soo Young; Porter, Brenda E; Friedman, Alon; Kaufer, Daniela
2016-09-01
Head trauma and vascular injuries are known risk factors for acquired epilepsy. The sequence of events that lead from the initial injury to the development of epilepsy involves complex plastic changes and circuit rewiring. In-depth, comprehensive understanding of the epileptogenic process is critical for the identification of disease-modifying targets. Here we review the complex interactions of cellular and extracellular components that may promote epileptogenesis, with an emphasis on the role of astrocytes. Emerging evidence demonstrates that astrocytes promptly respond to brain damage and play a critical role in the development of postinjury epilepsy. Astrocytes have been shown to regulate extracellular matrix (ECM) remodeling, which can affect plasticity and stability of synapses and, in turn, contribute to the epileptogenic process. From these separate lines of evidence, we present a hypothesis suggesting a possible role for astrocyte-regulated remodeling of ECM and perineuronal nets, a specialized ECM structure around fast-spiking inhibitory interneurons, in the development and progression of posttraumatic epilepsies. © 2016 Wiley Periodicals, Inc.
The potential of more accurate InSAR covariance matrix estimation for land cover mapping
NASA Astrophysics Data System (ADS)
Jiang, Mi; Yong, Bin; Tian, Xin; Malhotra, Rakesh; Hu, Rui; Li, Zhiwei; Yu, Zhongbo; Zhang, Xinxin
2017-04-01
Synthetic aperture radar (SAR) and Interferometric SAR (InSAR) provide both structural and electromagnetic information for the ground surface and therefore have been widely used for land cover classification. However, relatively few studies have developed analyses that investigate SAR datasets over richly textured areas where heterogeneous land covers exist and intermingle over short distances. One of main difficulties is that the shapes of the structures in a SAR image cannot be represented in detail as mixed pixels are likely to occur when conventional InSAR parameter estimation methods are used. To solve this problem and further extend previous research into remote monitoring of urban environments, we address the use of accurate InSAR covariance matrix estimation to improve the accuracy of land cover mapping. The standard and updated methods were tested using the HH-polarization TerraSAR-X dataset and compared with each other using the random forest classifier. A detailed accuracy assessment complied for six types of surfaces shows that the updated method outperforms the standard approach by around 9%, with an overall accuracy of 82.46% over areas with rich texture in Zhuhai, China. This paper demonstrates that the accuracy of land cover mapping can benefit from the 3 enhancement of the quality of the observations in addition to classifiers selection and multi-source data ingratiation reported in previous studies.
α-dystroglycan is a potential target of matrix metalloproteinase MMP-2.
Sbardella, Diego; Sciandra, Francesca; Gioia, Magda; Marini, Stefano; Gori, Alessandro; Giardina, Bruno; Tarantino, Umberto; Coletta, Massimo; Brancaccio, Andrea; Bozzi, Manuela
2015-01-01
Dystroglycan (DG) is a member of the glycoprotein complex associated to dystrophin and composed by two subunits, the β-DG, a transmembrane protein, and the α-DG, an extensively glycosylated extracellular protein. The β-DG ectodomain degradation by the matrix metallo-proteinases (i.e., MMP-2 and MMP-9) in both, pathological and physiological conditions, has been characterized in detail in previous publications. Since the amounts of α-DG and β-DG at the cell surface decrease when gelatinases are up-regulated, we investigated the degradation of α-DG subunit by MMP-2. Present data show, for the first time, that the proteolysis of α-DG indeed occurs on a native glycosylated molecule enriched from rabbit skeletal muscle. In order to characterize the α-DG portion, which is more prone to cleavage by MMP-2, we performed different degradations on tailored recombinant domains of α-DG spanning the whole subunit. The overall bulk of results casts light on a relevant susceptibility of the α-DG to MMP-2 degradation with particular reference to its C-terminal domain, thus opening a new scenario on the role of gelatinases (in particular of MMP-2) in the degradation of this glycoprotein complex, taking place in the course of pathological processes.
The ab initio model potential method. Second series transition metal elements
Barandiaran, Z.; Seijo, L. ); Huzinaga, S. )
1990-10-15
The {ital ab} {ital initio} core method potential model (AIMP) has already been presented in its nonrelativistic version and applied to the main group and first series transition metal elements (J. Chem. Phys. {bold 86}, 2132 (1987); {bold 91}, 7011 (1989)). In this paper we extend the AIMP method to include relativistic effects within the Cowan--Griffin approximation and we present relativistic Zn-like core model potentials and valence basis sets, as well as their nonrelativistic Zn-like core and Kr-like core counterparts. The pilot molecular calculations on YO, TcO, AgO, and AgH reveal that the 4{ital p} orbital is indeed a core orbital only at the end part of the series, whereas the 4{ital s} orbital can be safely frozen from Y to Cd. The all-electron and model potential results agree in 0.01--0.02 A in {ital R}{sub {ital e}} and 25--50 cm{sup {minus}1} in {bar {nu}}{sub {ital e}} if the same type of valence part of the basis set is used. The comparison of the relativistic results on AgH with those of the all-electron Dirac--Fock calculations by Lee and McLean is satisfactory: the absolute value of {ital R}{sub {ital e}} is reproduced within the 0.01 A margin and the relativistic contraction of 0.077 A is also very well reproduced (0.075 A). Finally, the relative magnitude of the effects of the core orbital change, mass--velocity potential, and Darwin potential on the net relativistic effects are analyzed in the four molecules studied.
Inversion of potential field data using the finite element method on parallel computers
NASA Astrophysics Data System (ADS)
Gross, L.; Altinay, C.; Shaw, S.
2015-11-01
In this paper we present a formulation of the joint inversion of potential field anomaly data as an optimization problem with partial differential equation (PDE) constraints. The problem is solved using the iterative Broyden-Fletcher-Goldfarb-Shanno (BFGS) method with the Hessian operator of the regularization and cross-gradient component of the cost function as preconditioner. We will show that each iterative step requires the solution of several PDEs namely for the potential fields, for the adjoint defects and for the application of the preconditioner. In extension to the traditional discrete formulation the BFGS method is applied to continuous descriptions of the unknown physical properties in combination with an appropriate integral form of the dot product. The PDEs can easily be solved using standard conforming finite element methods (FEMs) with potentially different resolutions. For two examples we demonstrate that the number of PDE solutions required to reach a given tolerance in the BFGS iteration is controlled by weighting regularization and cross-gradient but is independent of the resolution of PDE discretization and that as a consequence the method is weakly scalable with the number of cells on parallel computers. We also show a comparison with the UBC-GIF GRAV3D code.
Yuan, Zhimin; Yao, Jun; Wang, Fei; Guo, Zunwei; Dong, Zeqin; Chen, Feng; Hu, Yu; Sunahara, Geoffrey
2017-01-01
Artisanal zinc smelting activities, which had been widely applied in Bijie City, Guizhou Province, southwestern of China, can pollute surrounding farmlands. In the present study, 177 farmland topsoil samples of Bijie City were collected and 11 potentially toxic trace elements (PTEs), namely Pb, Zn, Cu, Ni, Co, Mn, Cr, V, Hg, As, and Cd were tested to characterize the concentrations, sources, and ecological risks. Mean concentrations of these PTEs in soils were (mg/kg) as follows: Pb (127), Zn (379), Cu (93.1), Ni (54.6), Co (26.2), Mn (1095), Cr (133), V (206), Hg (0.15), As (16.2), and Cd (3.08). Pb, Zn, and Cd had coefficients of variation greater than 100% and showed a high uneven distribution and spatial variability in the study area. Correlation coefficient analysis and principal component analysis (PCA) were used to quantify potential pollution sources. Results showed that Cu, Ni, Co, Mn, and V came from natural sources, whereas Pb, Zn, Hg, As, and Cd came from anthropogenic pollution sources. Geoaccumulation index and potential ecological risk indices were employed to study the pollution degree of PTEs, which revealed that Pb and Cd shared the greatest contamination and would pose serious ecological risks to the surrounding environment. The results of this study could help the local government managers to establish pollution control strategies and to secure food safety.
1993-01-01
Insulin-like growth factor binding proteins (IGFBPs) have been shown to serve as carrier proteins for the insulin-like growth factors (IGFs) and to modulate their biologic effects. Since extracellular matrix (ECM) has been shown to be a reservoir for IGF-I and IGF-II, we examined the ECM of cultured human fetal fibroblasts and found that IGFBP-5 was incorporated intact into ECM, while mostly inert proteolytic fragments were found in the medium. In contrast, two other forms of IGFBP that are secreted by these cells were either present in ECM in minimal amounts (IGFBP-3) or not detected (IGFBP-4). Likewise, when purified IGFBPs were incubated with ECM, IGFBP-5 bound preferentially. IGFBP-5 was found to bind to types III and IV collagen, laminin, and fibronectin. Increasing salt concentrations inhibited the binding of IGFBP-5 to ECM and accelerated the release of IGFBP-5 from ECM, suggesting an ionic basis for this interaction. ECM-associated IGFBP-5 had a sevenfold decrease in affinity for IGF-I compared to IGFBP-5 in solution. Furthermore, when IGFBP-5 was present in cell culture substrata, it potentiated the growth stimulatory effects of IGF- I on fibroblasts. When IGFBP-5 was present only in the medium, it was degraded to a 22-kD fragment and had no effect on IGF-I-stimulated growth. We conclude that IGFBP-5 is present in fibroblast ECM, where it is protected from degradation and can potentiate the biologic actions of IGF-I. These findings provide a molecular explanation for the association of the IGF's with the extracellular matrix, and suggest that the binding of the IGF's to matrix, via IGFBP-5, may be important in mediating the cellular growth response to these growth factors. PMID:7683690
Souza, Carolina C; Barreto, Tatiane de O; da Silva, Sydnei M; Pinto, Aldair W J; Figueiredo, Maria M; Rocha, Olguita G Ferreira; Cangussú, Silvia D; Tafuri, Wagner L
2014-08-01
Canine visceral leishmaniasis (CVL) is a severe and fatal systemic chronic inflammatory disease. We investigated the alterations in, and potential associations among, antioxidant enzymes, trace elements and histopathology in CVL. Blood and tissue levels of Cu-Zn superoxide dismutase, catalase and glutathione peroxidase were measured in mixed-breed dogs naturally infected with Leishmania infantum chagasi, symptomatic (n = 19) and asymptomatic (n = 11). Serum levels of copper, iron, zinc, selenium and nitric oxide, and plasma lipid peroxidation were measured. Histological and morphometric analyses were conducted of lesions in liver, spleen and lymph nodes. We found lower blood catalase and glutathione peroxidase activity to be correlated with lower iron and selenium respectively. However, higher activity of Cu-Zn superoxide dismutase was not correlated with the increase in copper and decreased in zinc observed in infected animals compared to controls. Organ tissue was characterized by lower enzyme activity in infected dogs than in controls, but this was not correlated with trace elements. Lipid peroxidation was higher in symptomatic than in asymptomatic and control dogs and was associated with lesions such as chronic inflammatory reaction, congestion, haemosiderin and fibrosis. Systemic iron deposition was observed primarily in the symptomatic dogs showing a higher tissue parasite load. Dogs with symptomatic CVL displayed enhanced LPO and Fe tissue deposition associated with decreased levels of antioxidant enzymes. These results showed new points in the pathology of CVL and might open new treatment perspectives associated with antioxidants and the role of iron in the pathogenesis of CVL.
de Souza, Edna Santos; Fernandes, Antonio Rodrigues; de Souza Braz, Anderson Martins; Sabino, Lorena Lira Leite; Alleoni, Luís Reynaldo Ferracciú
2015-01-01
The Trans-Amazonian Highway (TAH) is located in the northern region of Brazil, comprising a border region where agricultural, mining, and logging activities are the main activities responsible for fostering economic development, in addition to large hydroelectric plants. Such activities lead to environmental contamination by potentially toxic elements (PTEs). Environmental monitoring is only possible through the determination of element contents under natural conditions. Many extraction methods have been proposed to determine PTEs' bioavailability in the soil; however, there is no consensus about which extractor is most suitable. In this study, we determined the contents of PTEs in soils in the surroundings of TAH after mineral extraction with diethylenetriaminepentaacetic acid-triethanolamine (DTPA-TEA), Mehlich I, and Mehlich III solutions. Soil samples were collected in areas of natural vegetation in the vicinity of TAH in the state of Pará, Brazil. Chemical attributes and particle size were determined, besides concentrations of Fe, Al, Mn, and Ti by sulfuric acid digestion, Si after alkaline solution attack, and poorly crystalline Fe, Al, and "free" Fe oxides. Mehlich III solution extracted greater contents from Fe, Al, and Pb as compared to Mehlich I and DTPA-TEA and similar contents from Cd, Mn, Zn, and Cu. Significant correlations were found between concentrations of PTEs and the contents of Fe and Mn oxides as well as organic carbon and soil cation exchange capacity. Contents of Cu, Mn, Fe, and Zn by the three methods were positively correlated.
Souza, Carolina C; Barreto, Tatiane de O; da Silva, Sydnei M; Pinto, Aldair W J; Figueiredo, Maria M; Ferreira Rocha, Olguita G; Cangussú, Silvia D; Tafuri, Wagner L
2014-01-01
Canine visceral leishmaniasis (CVL) is a severe and fatal systemic chronic inflammatory disease. We investigated the alterations in, and potential associations among, antioxidant enzymes, trace elements and histopathology in CVL. Blood and tissue levels of Cu-Zn superoxide dismutase, catalase and glutathione peroxidase were measured in mixed-breed dogs naturally infected with Leishmania infantum chagasi, symptomatic (n = 19) and asymptomatic (n = 11). Serum levels of copper, iron, zinc, selenium and nitric oxide, and plasma lipid peroxidation were measured. Histological and morphometric analyses were conducted of lesions in liver, spleen and lymph nodes. We found lower blood catalase and glutathione peroxidase activity to be correlated with lower iron and selenium respectively. However, higher activity of Cu-Zn superoxide dismutase was not correlated with the increase in copper and decreased in zinc observed in infected animals compared to controls. Organ tissue was characterized by lower enzyme activity in infected dogs than in controls, but this was not correlated with trace elements. Lipid peroxidation was higher in symptomatic than in asymptomatic and control dogs and was associated with lesions such as chronic inflammatory reaction, congestion, haemosiderin and fibrosis. Systemic iron deposition was observed primarily in the symptomatic dogs showing a higher tissue parasite load. Dogs with symptomatic CVL displayed enhanced LPO and Fe tissue deposition associated with decreased levels of antioxidant enzymes. These results showed new points in the pathology of CVL and might open new treatment perspectives associated with antioxidants and the role of iron in the pathogenesis of CVL. PMID:24766461
Sánchez-López, Ariadna S; Carrillo-González, Rogelio; González-Chávez, Ma Del Carmen Angeles; Rosas-Saito, Greta Hanako; Vangronsveld, Jaco
2015-10-01
Retention of particles containing potentially toxic elements (PTEs) on plants that spontaneously colonize mine tailings was studied through comparison of washed and unwashed shoot samples. Zn, Pb, Cd, Cu, Ni, Co and Mn concentrations were determined in plant samples. Particles retained on leaves were examined by Scanning Electronic Microscopy and energy dispersive X-Ray analysis. Particles containing PTEs were detected on both washed and unwashed leaves. This indicates that the thorough washing procedure did not remove all the particles containing PTEs from the leaf surface, leading to an overestimation of the concentrations of PTEs in plant tissues. Particularly trichomes and fungal mycelium were retaining particles. The quantity and composition of particles varied among plant species and place of collection. It is obvious that plants growing on toxic mine tailings form a physical barrier against particle dispersion and hence limit the spread of PTEs by wind.
Warehime, Mick; Kłos, Jacek; Alexander, Millard H.
2015-01-21
This is the second in a series of papers detailing a MATLAB based implementation of the finite element method applied to collinear triatomic reactions. Here, we extend our previous work to reactions on coupled potential energy surfaces. The divergence of the probability current density field associated with the two electronically adiabatic states allows us to visualize in a novel way where and how nonadiabaticity occurs. A two-dimensional investigation gives additional insight into nonadiabaticity beyond standard one-dimensional models. We study the F({sup 2}P) + HCl and F({sup 2}P) + H{sub 2} reactions as model applications. Our publicly available code (http://www2.chem.umd.edu/groups/alexander/FEM) is general and easy to use.
Ciesielski, Tomasz M; Pastukhov, Mikhail V; Leeves, Sara A; Farkas, Julia; Lierhagen, Syverin; Poletaeva, Vera I; Jenssen, Bjørn M
2016-08-01
Lake Baikal is located in eastern Siberia in the center of a vast mountain region. Even though the lake is regarded as a unique and pristine ecosystem, there are existing sources of anthropogenic pollution to the lake. In this study, the concentrations of the potentially toxic trace elements As, Cd, Pb, Hg, and Se were analyzed in water, plankton, invertebrates, and fish from riverine and pelagic influenced sites in Lake Baikal. Concentrations of Cd, Hg, Pb and Se in Lake Baikal water and biota were low, while concentrations of As were similar or slightly higher compared to in other freshwater ecosystems. The bioaccumulation potential of the trace elements in both the pelagic and the benthic ecosystems differed between the Selenga Shallows (riverine influence) and the Listvenichnyĭ Bay (pelagic influence). Despite the one order of magnitude higher water concentrations of Pb in the Selenga Shallows, Pb concentrations were significantly higher in both pelagic and benthic fish from the Listvenichnyĭ Bay. A similar trend was observed for Cd, Hg, and Se. The identified enhanced bioavailability of contaminants in the pelagic influenced Listvenichnyĭ Bay may be attributed to a lower abundance of natural ligands for contaminant complexation. Hg was found to biomagnify in both benthic and pelagic Baikal food chains, while As, Cd, and Pb were biodiluted. At both locations, Hg concentrations were around seven times higher in benthic than in pelagic fish, while pelagic fish had two times higher As concentrations compared to benthic fish. The calculated Se/Hg molar ratios revealed that, even though Lake Baikal is located in a Se-deficient region, Se is still present in excess over Hg and therefore the probability of Hg induced toxicity in the endemic fish species of Lake Baikal is assumed to be low.
NASA Astrophysics Data System (ADS)
Parijskij, Yu. N.; Bursov, N. N.; Berlin, A. B.; Mingaliev, M. G.; Nizhelskij, N. A.; Stolyarov, V. A.; Tsybulev, P. G.; Semenova, T. A.; Khaikin, V. B.; Grechkin, A. A.
2013-04-01
We report the preliminary results of a deep sky survey in the field of 00h < RA < 24h, 40{./°}5 < 42{./°}5 with the RATAN-600 and its new focal 32-feed receiver matrix at the limiting radio frequency of 30 GHz, with the resolution up to 5″ in right ascension and 30″ in declination. The first results, including new estimates of the anisotropy of background radiation at the scales of ( l > 3000) and noise from discrete radio sources in the wavelength range between the NVSS and IRAS catalogs are listed.
Close, D.A.; Franks, L.A.; Kocimski, S.M.
1984-08-16
An invention is described that enables the quantitative simultaneous identification of the matrix materials in which fertile and fissile nuclides are embedded to be made along with the quantitative assay of the fertile and fissile materials. The invention also enables corrections for any absorption of neutrons by the matrix materials and by the measurement apparatus by the measurement of the prompt and delayed neutron flux emerging from a sample after the sample is interrogated by simultaneously applied neutrons and gamma radiation. High energy electrons are directed at a first target to produce gamma radiation. A second target receives the resulting pulsed gamma radiation and produces neutrons from the interaction with the gamma radiation. These neutrons are slowed by a moderator surrounding the sample and bathe the sample uniformly, generating second gamma radiation in the interaction. The gamma radiation is then resolved and quantitatively detected, providing a spectroscopic signature of the constituent elements contained in the matrix and in the materials within the vicinity of the sample. (LEW)
He Zhiguo; Fan Ying; Chao Kuangta
2010-03-01
We calculate the relativistic correction to J/{psi} production in the color-singlet process e{sup +}e{sup -{yields}}J/{psi}+gg at B factories. We employ the nonrelativistic QCD factorization approach, where the short-distance coefficients are calculated perturbatively and the long-distance matrix elements are extracted from the decays of J/{psi} into e{sup +}e{sup -} and light hadrons. We find that the O(v{sup 2}) relativistic correction can enhance the cross section by a factor of 20-30%, comparable to the enhancement due to the O({alpha}{sub s}) radiative correction obtained earlier. Combining the relativistic correction with the QCD radiative correction, we find that the color-singlet contribution to e{sup +}e{sup -{yields}}J/{psi}+gg can saturate the latest observed cross section {sigma}(e{sup +}e{sup -{yields}}J/{psi}+X{sub non-cc})=0.43{+-}0.09{+-}0.09 pb by Belle, thus leaving little room to the color-octet contributions. This gives a very stringent constraint on the color-octet contribution, and may imply that the values of color-octet matrix elements are much smaller than expected earlier by using the naive velocity scaling rules or extracted from fitting experimental data with the leading-order calculations.
Trace element behaviour at cold seeps and the potential export of dissolved iron to the ocean
NASA Astrophysics Data System (ADS)
Lemaitre, Nolwenn; Bayon, Germain; Ondréas, Hélène; Caprais, Jean-Claude; Freslon, Nicolas; Bollinger, Claire; Rouget, Marie-Laure; de Prunelé, Alexis; Ruffine, Livio; Olu-Le Roy, Karine; Sarthou, Géraldine
2014-10-01
Seawater samples were collected by submersible above methane seeps in the Gulf of Guinea (Regab and Baboon pockmarks) in order to investigate the behaviour of iron (Fe), manganese (Mn) and rare earth elements (REE) during fluid seepage. Our aim was to determine whether cold seeps may represent potential sources of dissolved chemical species to the ocean. Dissolved (<0.45 μm filtered samples) and total dissolvable (unfiltered samples) concentrations were determined over ∼50 m long vertical transects above the seafloor and at various discrete locations within the pockmarks. We show that substantial amounts of Fe and Mn are released into seawater during seepage of methane-rich fluids. Mn is exported almost quantitatively in the dissolved form (more than 90% of total Mn; mean MnDISS∼12±11 nmol/kg). Although a significant fraction of Fe is bound to particulate phases, the dissolved iron pool still accounts on average for approximately 20 percent of total iron flux at vent sites (mean FeDISS∼22±11 nmol/kg). This dissolved Fe fraction also appears to remain stable in the water column. In contrast, there was no evidence for any significant benthic fluxes of pore water REE associated with fluid seepage at the studied sites. Overall, our results point towards distinct trace element behaviour during fluid seepage, with potential implications for the marine geochemical budget. The absence of any dissolved REE enrichments in bottom waters clearly indicates effective removal in sub-surface sediments. Most likely, precipitation of authigenic mineral phases at cold seeps (i.e. carbonates) represents a net sink for these elements. While Mn appears to behave near-conservatively during fluid seepage, the observed relative stability of dissolved Fe in the water column above seepage sites could be explained by complexation with strong organic ligands and/or the presence of Fe-bearing sulfide nanoparticles, as reported previously for submarine hydrothermal systems. Considering
NASA Technical Reports Server (NTRS)
Wang, R.; Demerdash, N. A.
1990-01-01
The effects of finite element grid geometries and associated ill-conditioning were studied in single medium and multi-media (air-iron) three dimensional magnetostatic field computation problems. The sensitivities of these 3D field computations to finite element grid geometries were investigated. It was found that in single medium applications the unconstrained magnetic vector potential curl-curl formulation in conjunction with first order finite elements produce global results which are almost totally insensitive to grid geometries. However, it was found that in multi-media (air-iron) applications first order finite element results are sensitive to grid geometries and consequent elemental shape ill-conditioning. These sensitivities were almost totally eliminated by means of the use of second order finite elements in the field computation algorithms. Practical examples are given in this paper to demonstrate these aspects mentioned above.
Long interspersed nuclear elements (LINE-1): potential triggers of systemic autoimmune disease.
Crow, Mary K
2010-02-01
Recent advances have identified immune complexes containing nucleic acids as stimuli for toll-like receptors and inducers of type I interferon (IFN). While a similar mechanism may serve to amplify immune system activation and production of inflammatory mediators in vivo in the context of systemic autoimmune diseases, the initial triggers of autoimmunity have not been defined. In this review, we describe a category of potential inducers of autoimmunity, the endogenous retroelements, with a particular focus on long interspersed nuclear elements (LINE-1, L1). Increased expression of L1 transcripts or decreased degradation of L1 DNA or RNA could provide potent stimuli for an innate immune response, priming of the immune system, and induction of autoimmunity and inflammation. Genomic and genetic variations among individuals, sex-related differences in L1 regulation, and environmental triggers are among the potential mechanisms that might account for increased L1 expression. Induction of type I IFN by L1-enriched nucleic acids through TLR-independent pathways could represent a first step in the complex series of events leading to systemic autoimmune disease.
The rare earth element potential of kaolin deposits in the Bohemian Massif (Czech Republic, Austria)
NASA Astrophysics Data System (ADS)
Höhn, S.; Frimmel, H. E.; Pašava, J.
2014-12-01
Four kaolin deposits in the Bohemian Massif were studied in order to assess the potential for the recovery of rare earth elements (REE) as by-products from the residue after extraction and refining of the raw kaolin. The behaviour of REE + Y during kaolinitization was found to be largely a function of pre-alteration mineralogy. In the examples studied, i.e. granite-derived deposits of Kriechbaum (Austria) and Božičany, and arkose-derived deposits of Kaznějov and Podbořany (all Czech Republic), the REE + Y are predominantly hosted by monazite which has remained unaffected by kaolinitization. The overall REE + Y content of the variably kaolinitized rocks is strongly dependent on their genesis. While ion adsorption plays only a minor role in the concentration of REE + Y in the studied kaolinitized rocks, the processing and refining of the raw kaolin leads to residues that are enriched in REE + Y by a factor of up to 40. The use of a magnetic separator and a hydrocyclone in the processing of the raw material can yield REE + Y contents of as much as 0.77 wt%. Although this value compares well with the REE + Y concentration in some potentially economic REE + Y projects elsewhere, the overall tonnage of the (REE + Y)-enriched residue is by far not sufficient to consider economic extraction of REE + Y as by-product. Our results are most probably applicable also to other kaolin deposits derived from the weathering of Hercynian basement granites elsewhere (e.g. in Saxonia and Bavaria, Germany). Overall, the potential for REE + Y production as by-product from kaolin mining has to be regarded as minimal.
NASA Astrophysics Data System (ADS)
Tarana, Michal; Čurík, Roman
2016-05-01
We introduce a computational method developed for study of long-range molecular Rydberg states of such systems that can be approximated by two electrons in a model potential of the atomic cores. The method is based on a two-electron R-matrix approach inside a sphere centered on one of the atoms. The wave function is then connected to a Coulomb region outside the sphere via a multichannel version of the Coulomb Green's function. This approach is applied to a study of Rydberg states of Rb2 for internuclear separations R from 40 to 320 bohrs and energies corresponding to n from 7 to 30. We report bound states associated with the low-lying 3Po resonance and with the virtual state of the rubidium atom that turn into ion-pair-like bound states in the Coulomb potential of the atomic Rydberg core. The results are compared with previous calculations based on single-electron models employing a zero-range contact-potential and short-range modele potential. Czech Science Foundation (Project No. P208/14-15989P).
Potentially toxic element fractionation in technosoils using two sequential extraction schemes.
Qasim, Bashar; Motelica-Heino, Mikael
2014-04-01
This study reports the chemical fractionation of several potentially toxic elements (Zn, Pb, Cd, As, and Sb) in contaminated technosoils of two former smelting and mining areas using two sequential extraction schemes. The extraction schemes used in this study were the Tessier's scheme and a modified BCR scheme. The fractions were rearranged into four equivalent fractions defined as acid soluble, reducible, oxidizable, and residual to compare the results obtained from two sequential extraction schemes. Surface soils were samples from a waste landfill contaminated with Zn, Pb, and Cd located at Mortagne-du-Nord (MDN; North France) and from a settling basin contaminated with PTE such as As, Pb, and Sb located at La Petite Faye (LPF; Limoges, France). The study of the Zn, Pb, Cd, As, and Sb partitioning in the acid soluble, reducible, oxidizable, and residual fractions of the technosoils revealed that Zn, Cd, and Pb were mainly associated with the acid soluble and reducible fractions for MDN site, while As, Sb, and Pb were associated with residual fraction for LPF site. Fractionation results indicate that the percentages of Zn, Pb, Cd, As, and Sb extracted in Fe-Mn oxide bound fraction of Tessier's scheme were always higher than those extracted by modified BCR scheme. This may be attributed to the stronger Tessier's scheme conditions used to extract this fraction. In contrast the percentages of Zn, Pb, Cd, As, and Sb extracted in the organic fraction of the modified BCR scheme were always higher than those of the Tessier's scheme. The order of mobility of PTE was as follows: Cd > Zn > Pb in MDN site and As > Sb > Pb in LPF site. PTE were distributed in all soil fractions, with the most relevant enrichments in extractable and residual fractions. A significant amount of Cd, Pb, and Zn were rather mobile, which suggests that these elements can be readily available to plants and soil organisms.
NASA Astrophysics Data System (ADS)
Szigeti, Tamás; Kertész, Zsófia; Dunster, Christina; Kelly, Frank J.; Záray, Gyula; Mihucz, Victor G.
2014-09-01
Fifty samples of indoor and outdoor PM2.5 were collected onto quartz fiber and Teflon membrane filters in five office buildings equipped with heating, ventilation and air-conditioning system for 8 h daily in order to coincide with the work shift of employees. Samples were analyzed for i) mass concentration; ii) elemental concentration; and iii) oxidative potential (OP) through antioxidant depletion. The PM2.5 mass concentration exceeded the annual mean guideline of 10 μg m-3 WHO in 50% of the samples. Indoor and outdoor PM2.5 mass concentrations correlated almost linearly. Proton-induced X-ray emission (PIXE) spectrometry was used for the monitoring of 21 elements. Quantitative determination was achieved in the case of Teflon filters only for Al, Si, S, Cl, K, Ca, Ti, Cr, Mn, Fe and Zn at ng m-3 concentration level. Quartz fiber filters were less adequate for the PIXE measurements due to their greater thickness and filamentary structure. Ca, Cr, Zn and Ti had generally higher concentration (mg g-1) indoors. Indoor/outdoor (I/O) OP values were higher than one in 14% and 57% of the samples in the case of ascorbate and reduced glutathione (GSH), respectively. Spatial and temporal variations of OP were observed across the office buildings. The I/O ratios for OP, Cr and Zn concentrations in the case of GSH were higher for three buildings. Significant relationship was observed between GSH oxidation and Cr and Zn concentrations. Thus, employees were exposed to a higher extent to reactive oxygen species in three buildings.
Distribution of potentially hazardous trace elements in coals from Shanxi province, China
Zhang, J.Y.; Zheng, C.G.; Ren, D.Y.; Chou, C.-L.; Liu, J.; Zeng, R.-S.; Wang, Z.P.; Zhao, F.H.; Ge, Y.T.
2004-01-01
Shanxi province, located in the center of China, is the biggest coal base of China. There are five coal-forming periods in Shanxi province: Late Carboniferous (Taiyuan Formation), Early Permian (Shanxi Formation), Middle Jurassic (Datong Formation), Tertiary (Taxigou Formation), and Quaternary. Hundred and ten coal samples and a peat sample from Shanxi province were collected and the contents of 20 potentially hazardous trace elements (PHTEs) (As, B, Ba, Cd, Cl, Co, Cr, Cu, F, Hg, Mn, Mo, Ni, Pb, Sb, Se, Th, U, V and Zn) in these samples were determined by instrumental neutron activation analysis, atomic absorption spectrometry, cold-vapor atomic absorption spectrometry, ion chromatography spectrometry, and wet chemical analysis. The result shows that the brown coals are enriched in As, Ba, Cd, Cr, Cu, F and Zn compared with the bituminous coals and anthracite, whereas the bituminous coals are enriched in B, Cl, Hg, and the anthracite is enriched in Cl, Hg, U and V. A comparison with world averages and crustal abundances (Clarke values) shows that the Quaternary peat is highly enriched in As and Mo, Tertiary brown coals are highly enriched in Cd, Middle Jurassic coals, Early Permian coals and Late Carboniferous coals are enriched in Hg. According to the coal ranks, the bituminous coals are highly enriched in Hg, whereas Cd, F and Th show low enrichments, and the anthracite is also highly enriched in Hg and low enrichment in Th. The concentrations of Cd, F, Hg and Th in Shanxi coals are more than world arithmetic means of concentrations for the corresponding elements. Comparing with the United States coals, Shanxi coals show higher concentrations of Cd, Hg, Pb, Se and Th. Most of Shanxi coals contain lower concentrations of PHTEs. ?? 2004 Elsevier Ltd. All rights reserved.
Transposable genetic elements in Spirulina and potential applications for genetic engineering
NASA Astrophysics Data System (ADS)
Hiroyuki, Kojima; Qin, Song; Thankappan, Ajith Kumar; Yoshikazu, Kawata; Shin-Ichi, Yano
1998-03-01
Transposable elements in cyanobacteria are briefly reviewed. Evidence is presented to show that transposable elements in Spirulina platensis is actually reflected on the phenotype change, i e., helical to straight filaments. Transposition intermediates of DNA were isolated from the extrachromosome and the transposition was related to helical variations in Spirulina. Uses of transposable elements for microalgal recombination are discussed based on the transposition mechanism.
Nannoni, Francesco; Rossi, Sara; Protano, Giuseppe
2016-06-01
A biogeochemical field study was carried out in the industrial area of Kosovska Mitrovica in northern Kosovo, where agricultural soils were contaminated by potentially toxic elements due to smelting activity. Total and bioavailable contents of As, Cd, Co, Cu, Pb, Sb, U and Zn in soil and their concentrations in maize roots and grains were determined. Soil contamination by As, Cd, Cu, Pb, Sb and Zn was variable from slightly to highly contaminated soils and influenced both the bioavailable fraction and accumulation of these potentially toxic elements in maize tissues. The comparison between potentially toxic element concentrations in roots and grains indicated that maize is able to limit the transfer of non-essential elements to edible parts. The plant-to-soil bioconcentration indices suggested that the transfer of potentially toxic elements from soil to plant was predicted better by bioavailable concentrations than by the total contents. These indices further identified some competitions and interactions among these elements in root uptake and root-to-grain translocation.
NASA Astrophysics Data System (ADS)
Qasim, Bashar; Motelica-Heino, Mikael
2014-05-01
High metal and metalloid concentrations in soils have negative effects on terrestrial ecosystems and generate potential health risk. Mining and smelting activities are the major source of metal contamination by release a huge amounts of these potentially toxic elements (PTE) into the environment. Since the determination of the total concentration of PTE in soils does not give sufficient information about their mobility and toxicity, additional information on their bioavailability and their chemical speciation is required. Our study aimed at reporting the chemical fractionation and phytoavailability assessment of several PTE (Zn, Pb, Cd, As and Sb) in contaminated technosoils of two former smelting and mining areas. Soil samples were taken from a metallophyte grassland contaminated with Zn, Pb and Cd located at Mortagne - du -Nord (MDN) (North France) and from a former mining settling basin contaminated with As, Pb and Sb located at la Petite Faye (LPF) (Limoges district, France). Two sequential extraction schemes were used to evaluate the PTE speciation in various technosoils as operationally defined fractions. The extraction schemes used in this study were the Tessier's scheme and a modified BCR scheme. The fractions were rearranged into four equivalent fractions defined as acid soluble, reducible, oxidisable and residual fraction. To assess the metals and metalloids phytoavailability a series of selective single extraction procedures (CaCl2, NaNO3, NH4NO3, DTPA and EDTA) were used together with short-term germination tests with dwarf beans whose primary leaves were analyzed for their PTE concentration after 21 days of sowing under controlled conditions (16h light/8h darkness regime, 25°C/21°C, relative humidity of 55 - 65% and photon flux of 150 μE m-2s-1). Our results indicates that Zn, Cd and Pb were mainly associated with the acid soluble and reducible fractions for the MDN site, while As, Sb and Pb were mostly associated with residual fraction for the LPF
Pangilinan, Monica
2010-05-01
The top quark produced through the electroweak channel provides a direct measurement of the V_{tb} element in the CKM matrix which can be viewed as a transition rate of a top quark to a bottom quark. This production channel of top quark is also sensitive to different theories beyond the Standard Model such as heavy charged gauged bosons termed W'. This thesis measures the cross section of the electroweak produced top quark using a technique based on using the matrix elements of the processes under consideration. The technique is applied to 2.3 fb^{-1} of data from the D0 detector. From a comparison of the matrix element discriminants between data and the signal and background model using Bayesian statistics, we measure the cross section of the top quark produced through the electroweak mechanism σ(p$\\bar{p}$ → tb + X, tqb + X) = 4.30_{-1.20}^{+0.98} pb. The measured result corresponds to a 4.9σ Gaussian-equivalent significance. By combining this analysis with other analyses based on the Bayesian Neural Network (BNN) and Boosted Decision Tree (BDT) method, the measured cross section is 3.94 ± 0.88 pb with a significance of 5.0σ, resulting in the discovery of electroweak produced top quarks. Using this measured cross section and constraining |V_{tb}| < 1, the 95% confidence level (C.L.) lower limit is |V_{tb}| > 0.78. Additionally, a search is made for the production of W' using the same samples from the electroweak produced top quark. An analysis based on the BDT method is used to separate the signal from expected backgrounds. No significant excess is found and 95% C.L. upper limits on the production cross section are set for W' with masses within 600-950 GeV. For four general models of W{prime} boson production using decay channel W' → t$\\bar{p}$, the lower mass limits are the following: M(W'_{L} with SM couplings) > 840 GeV; M(W'_{R}) > 880 GeV or 890 GeV if the right-handed neutrino is
NASA Astrophysics Data System (ADS)
Pangilinan, Monica
The top quark produced through the electroweak channel provides a direct measurement of the Vtb element in the CKM matrix which can be viewed as a transition rate of a top quark to a bottom quark. This production channel of top quark is also sensitive to different theories beyond the Standard Model such as heavy charged gauged bosons termed W'. This thesis measures the cross section of the electroweak produced top quark using a technique based on using the matrix elements of the processes under consideration. The technique is applied to 2.3 fb--1 of data from the DO detector. From a comparison of the matrix element discriminants between data and the signal and background model using Bayesian statistics, we measure the cross section of the top quark produced through the electroweak mechanism spp¯→ tb+X,tqb+X=4.30+0.98-1.2 0pb The measured result corresponds to a 4.9sigma Gaussian-equivalent significance. By combining this analysis with other analyses based on the Bayesian Neural Network (BNN) and Boosted Decision Tree (BDT) method, the measured cross section is 3.94 +/- 0.88 pb with a significance of 5.0sigma, resulting in the discovery of electroweak produced top quarks. Using this measured cross section and constraining |Vtb| < 1, the 95% confidence level (C.L.) lower limit is |Vtb| > 0.78. Additionally, a search is made for the production of W' using the same samples from the electroweak produced top quark. An analysis based on the BDT method is used to separate the signal from expected backgrounds. No significant excess is found and 95% C.L. upper limits on the production cross section are set for W' with masses within 600--950 GeV. For four general models of W' boson production using decay channel W' → tb¯, the lower mass limits are the following: M( W'L with SM couplings) > 840 GeV; M( W'R ) > 880 GeV or 890 GeV if the right-handed neutrino is lighter or heavier than W'R ; and M( W'L+R ) > 915 GeV.
The Force Exerted by the Membrane Potential During Protein Import into the Mitochondrial Matrix
NASA Technical Reports Server (NTRS)
Shariff, Karim; Ghosal, Sandip; Matouschek, Andreas
2002-01-01
The electrostatic force exerted on a targeting sequence by the electrical potential across the inner mitochondrial membrane is calculated and found to vary from 1.4 pN to 2.2 pN (per unit elementary charge) as the radius of the inner membrane pore (assumed aqueous) is varied from 12 to 6.5 Angstroms, its measured range. Since the pore is not very much wider than the distance between water molecules, the full shielding effect of water may not be present; the extreme case of a nonaqueous pore gives a force of 3.1 pN per unit charge, which represents an upper limit. When applied to mitochondrial import experiments on the protein harness, these results imply that a force of 11 plus or minus 4 pN is sufficient to catalyze the unfolding of harness during import. Comparison of these results with unfolding forces measured using atomic force microscopy suggests that the two are not inconsistent.
The force exerted by the membrane potential during protein import into the mitochondrial matrix
NASA Technical Reports Server (NTRS)
Shariff, Karim; Ghosal, Sandip; Matouschek, Andreas
2004-01-01
The force exerted on a targeting sequence by the electrical potential across the inner mitochondrial membrane is calculated on the basis of continuum electrostatics. The force is found to vary from 3.0 pN to 2.2 pN (per unit elementary charge) as the radius of the inner membrane pore (assumed aqueous) is varied from 6.5 to 12 A, its measured range. In the present model, the decrease in force with increasing pore width arises from the shielding effect of water. Since the pore is not very much wider than the distance between water molecules, the full shielding effect of water may not be present; the extreme case of a purely membranous pore without water gives a force of 3.2 pN per unit charge, which should represent an upper limit. When applied to mitochondrial import experiments on the protein barnase, these results imply that forces between 11 +/- 2 pN and 13.5 +/- 2.5 pN catalyze the unfolding of barnase in those experiments. A comparison of these results with unfolding forces measured using atomic force microscopy is made.
Fault diagnosis of rolling element bearing based on S transform and gray level co-occurrence matrix
NASA Astrophysics Data System (ADS)
Zhao, Minghang; Tang, Baoping; Tan, Qian
2015-08-01
Time-frequency analysis is an effective tool to extract machinery health information contained in non-stationary vibration signals. Various time-frequency analysis methods have been proposed and successfully applied to machinery fault diagnosis. However, little research has been done on bearing fault diagnosis using texture features extracted from time-frequency representations (TFRs), although they may contain plenty of sensitive information highly related to fault pattern. Therefore, to make full use of the textural information contained in the TFRs, this paper proposes a novel fault diagnosis method based on S transform, gray level co-occurrence matrix (GLCM) and multi-class support vector machine (Multi-SVM). Firstly, S transform is chosen to generate the TFRs due to its advantages of providing frequency-dependent resolution while keeping a direct relationship with the Fourier spectrum. Secondly, the famous GLCM-based texture features are extracted for capturing fault pattern information. Finally, as a classifier which has good discrimination and generalization abilities, Multi-SVM is used for the classification. Experimental results indicate that the GLCM-based texture features extracted from TFRs can identify bearing fault patterns accurately, and provide higher accuracies than the traditional time-domain and frequency-domain features, wavelet packet node energy or two-direction 2D linear discriminant analysis based features of the same TFRs in most cases.
2009-01-01
Introduction Autologous chondrocyte transplantation (ACT) is a routine technique to regenerate focal cartilage lesions. However, patients with osteoarthritis (OA) are lacking an appropriate long-lasting treatment alternative, partly since it is not known if chondrocytes from OA patients have the same chondrogenic differentiation potential as chondrocytes from donors not affected by OA. Methods Articular chondrocytes from patients with OA undergoing total knee replacement (Mankin Score > 3, Ahlbäck Score > 2) and from patients undergoing ACT, here referred to as normal donors (ND), were isolated applying protocols used for ACT. Their chondrogenic differentiation potential was evaluated both in high-density pellet and scaffold (Hyaff-11) cultures by histological proteoglycan assessment (Bern Score) and immunohistochemistry for collagen types I and II. Chondrocytes cultured in monolayer and scaffolds were subjected to gene expression profiling using genome-wide oligonucleotide microarrays. Expression data were verified by using real-time PCR. Results Chondrocytes from ND and OA donors demonstrated accumulation of comparable amounts of cartilage matrix components, including sulphated proteoglycans and collagen types I and II. The mRNA expression of cartilage markers (ACAN, COL2A1, COMP, CRTL1, SOX9) and genes involved in matrix synthesis (BGN, CILP2, COL9A2, COL11A1, TIMP4) was highly induced in 3D cultures of chondrocytes from both donor groups. Genes associated with hypertrophic or OA cartilage (ALPL, COL1A1, COL3A1, COL10A1, MMP13, POSTN, PTH1R, RUNX2) were not significantly regulated between the two groups of donors. The expression of 661 genes, including COMP, FN1, and SOX9, was differentially regulated between OA and ND chondrocytes cultured in monolayer. During scaffold culture, the differences diminished between the OA and ND chondrocytes, and only 184 genes were differentially regulated. Conclusions Only few genes were differentially expressed between OA and
Plumejeaud, Sophie; Reis, Amelia Paula; Tassistro, Virginie; Patinha, Carla; Noack, Yves; Orsière, Thierry
2016-10-22
Due to their behavioral characteristics, young children are vulnerable to the ingestion of indoor dust, often contaminated with chemicals that are potentially harmful. Exposure to potentially harmful elements (PHEs) is currently exacerbated by their widespread use in several industrial, agricultural, domestic and technological applications. PHEs cause adverse health effects on immune and nervous systems and can lead to cancer development via genotoxic mechanisms. The present study is an integrated approach that aims at assessing the genotoxicity of bioaccessible PHEs following ingestion of contaminated house dust. A multidisciplinary methodology associating chemical characterization of five house dust samples, extraction of the bioaccessible PHEs in gastric extracts by the unified BARGE method, determination of the bioaccessible fraction and in vitro genotoxicity of gastric extracts in adenocarcinoma gastric human (AGS) cells was developed. The five gastric extracts induced dose-dependent genotoxicity in AGS cells. Copper (bioaccessible concentration up to 111 mg/kg) was probably the prevalent PHE inducing primary DNA damage (up to 5.1-fold increase in tail DNA at 0.53 g/l of gastric extract). Lead (bioaccessible concentration up to 245 mg/kg) was the most prevalent PHE inducing chromosome-damaging effects (r = 0.55; p < 0.001 for micronucleated cells induction). The association of principal component analysis and Spearman's correlations was decisive to understand the chromosome-damaging properties of the bioaccessible PHEs in AGS cells. This methodology could be used on a larger-scale study to provide useful information for science-based decision-making in regulatory policies, and a better estimation of human exposure and associated health risks.
NASA Astrophysics Data System (ADS)
Chen, Fan; Chen, Jin
2011-11-01
Pinus armandii is a species of pine native to China with a wide geographical distribution and large-wingless seeds (about 300 mg). The study is to determine the variation in seed dispersal traits among populations within a relative small geographic scale and furthermore to explore if the trait differentiation results in the differences in dispersers, in particular nutcrackers ( Nucifraga caryocatactes) and scatter-hoarding rodents. We conducted studies at five sites at different elevations in northwest Yunnan Province. The study sites are separated by 10-200 km and divided into populations partly isolated by mountains and rivers. The cone and seed traits diverged significantly among the five study sites while the traits among individual trees at each site did not differ significantly. Nutcrackers and scatter-hoarding rodents presented conflicting preference in cone and seed traits: nutcrackers preferred smaller cones with smaller seeds, which increased the foraging efficiency of nutcrackers; while scatter-hoarding rodents tended to cache larger seeds. Consistent with variation in preferences by nutcrackers and scatter-hoarding rodents, in nutcracker-dominated sites, pines were characterized by smaller cones, smaller seeds, and thinner seed coats; while in sites where nutcrackers were not abundant, pines had relatively larger cones with larger seeds, which could enhance caching activities by scatter-hoarding rodents. The study provided some key elements for potential selection mosaic on cone and seed traits of a long-lived perennial tree among populations with limited geographical range.
Planktonic foraminiferal rare earth elements as a potential new aeolian dust proxy
NASA Astrophysics Data System (ADS)
Chou, C.; Liu, Y.; Lo, L.; Wei, K.; Shen, C.
2012-12-01
Characteristics of rare earth elements (REEs) have widely been used as important tracers in many fields of earth sciences, including lithosphere research, environmental change, ocean circulation and other natural carbonate materials. Foraminiferal test REE signatures have been suggested to reflect ambient seawater conditions and serve as valuable proxies in the fields of paleoceanography and paleoclimate. Here we present a 60-kyr planktonic foraminifera Globigerinoides ruber (white, 250-300 μm) REE record of a sediment core MD05-2925 (9°20.61'S, 151°27.61'E, water depth 1660 m) from the Solomon Sea. The REE diagram shows two dominant sources of local seawater and nearby terrestrial input. The variability of foraminiferal REE/Ca time series is different from Mg/Ca-inferred sea surface temperature and δ18O records during the past 60-kyr. This inconsistency suggests that planktonic foraminiferal REE content cannot result only from changes in ice volume and temperature. Synchroneity between high planktonic foraminiferal REE content and Antarctic ice core dust amount record implies the same dust sources, probably from Australia or mainland China. Our results suggest that foraminiferal REE can potentially be as a new dust proxy and record dry/humid conditions at the source area.
Bioconcentration factors and the risk concentrations of potentially toxic elements in garden soils.
Boim, Alexys Giorgia Friol; Melo, Leônidas Carrijo Azevedo; Moreno, Fabio Netto; Alleoni, Luís Reynaldo Ferracciú
2016-04-01
Empirical models describe soil-plant transfers to explain the variations in the occurrence of potentially toxic elements (PTE) in soils and to estimate the Bioconcentration Factor (BCF). In this study, results were selected based on data in the literature on soils of humid tropical and temperate regions to evaluate soil-plant transfer models, to calculate the BCF and to derive risk concentrations of Cu, Cr, Pb, Ni and Zn present in the exposure pathway leading to the consumption of contaminated vegetables. The Cetesb (Environmental Agency of the State of Sao Paulo, Brazil) mathematical model was used to derive the risk posed by soil concentrations in urban and rural exposure scenarios. The results of the pseudo total contents of PTE in the soil and the contents absorbed by plants were compared and the BCFs were calculated by the use of geometric means, including a correction factor appropriate to each particular type of soil. Differences were observed between BCFs calculated for each climate region: humid tropical (HTR) and temperate (TE), which the first one presented the highest values to BCF in leaves and the lowest BCF values for root, except Ni, compared to second one. The soil concentrations with the highest risk were found in humid tropical regions as compared with those found in temperate regions, except for Ni. The obtained BCFs may contribute to any future revisions of guideline values as well as help other state environmental agencies to establish their own guideline values.
Potential of minicomputer/array-processor system for nonlinear finite-element analysis
NASA Technical Reports Server (NTRS)
Strohkorb, G. A.; Noor, A. K.
1983-01-01
The potential of using a minicomputer/array-processor system for the efficient solution of large-scale, nonlinear, finite-element problems is studied. A Prime 750 is used as the host computer, and a software simulator residing on the Prime is employed to assess the performance of the Floating Point Systems AP-120B array processor. Major hardware characteristics of the system such as virtual memory and parallel and pipeline processing are reviewed, and the interplay between various hardware components is examined. Effective use of the minicomputer/array-processor system for nonlinear analysis requires the following: (1) proper selection of the computational procedure and the capability to vectorize the numerical algorithms; (2) reduction of input-output operations; and (3) overlapping host and array-processor operations. A detailed discussion is given of techniques to accomplish each of these tasks. Two benchmark problems with 1715 and 3230 degrees of freedom, respectively, are selected to measure the anticipated gain in speed obtained by using the proposed algorithms on the array processor.
Marine phosphorites as potential resources for heavy rare earth elements and yttrium
Hein, James; Koschinsky, Andrea; Mikesell, Mariah; Mizell, Kira; Glenn, Craig R.; Wood, Ray
2016-01-01
Marine phosphorites are known to concentrate rare earth elements and yttrium (REY) during early diagenetic formation. Much of the REY data available are decades old and incomplete, and there has not been a systematic study of REY distributions in marine phosphorite deposits that formed over a range of oceanic environments. Consequently, we initiated this study to determine if marine phosphorite deposits found in the global ocean host REY concentrations of high enough grade to be of economic interest. This paper addresses continental-margin (CM) and open-ocean seamount phosphorites. All 75 samples analyzed are composed predominantly of carbonate fluorapatite and minor detrital and authigenic minerals. CM phosphorites have low total REY contents (mean 161 ppm) and high heavy REY (HREY) complements (mean 49%), while seamount phosphorites have 4–6 times higher individual REY contents (except for Ce, which is subequal; mean ΣREY 727 ppm), and very high HREY complements (mean 60%). The predominant causes of higher concentrations and larger HREY complements in seamount phosphorites compared to CM phosphorites are age, changes in seawater REY concentrations over time, water depth of formation, changes in pH and complexing ligands, and differences in organic carbon content in the depositional environments. Potential ore deposits with high HREY complements, like the marine phosphorites analyzed here, could help supply the HREY needed for high-tech and green-tech applications without creating an oversupply of the LREY.
NASA Technical Reports Server (NTRS)
Grzybowski, J. M.; Allen, R. O.
1974-01-01
The factors that affect the preferred positions of cations in ionic solid solutions were investigated utilizing vibrational spectroscopy. Solid solutions of the sulfate and chromate ions codoped with La(+3) and Ca(+2) in a KBr host lattice were examined as a function of the polyvalent cation concentration. The cation-anion pairing process was found to be random for Ca(+2), whereas the formation of La(+3)-SO4(-2) ion pairs with a C2 sub v bonding geometry is highly preferential to any type of La(+3)-CrO4(-2) ion pair formation. The relative populations of ion pair site configurations are discussed in terms of an energy-entropy competition model which can be applied to the partition of trace elements during magmatic processes.
NASA Astrophysics Data System (ADS)
Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Ambrose, D. J.; An, F. F.; An, Q.; Bai, J. Z.; Ferroli, R. Baldini; Ban, Y.; Bennett, J. V.; Bertani, M.; Bian, J. M.; Boger, E.; Bondarenko, O.; Boyko, I.; Braun, S.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Cheng, H. P.; Chu, X. K.; Chu, Y. P.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; Ding, W. M.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, Y.; Fava, L.; Feng, C. Q.; Fu, C. D.; Fu, J. L.; Fuks, O.; Gao, Q.; Gao, Y.; Geng, C.; Goetzen, K.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, T.; Guo, Y. P.; Guo, Y. P.; Han, Y. L.; Harris, F. A.; He, K. L.; He, M.; He, Z. Y.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Huang, G. M.; Huang, G. S.; Huang, J. S.; Huang, L.; Huang, X. T.; Huang, Y.; Hussain, T.; Ji, C. S.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. L.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Kloss, B.; Kopf, B.; Kornicer, M.; Kuehn, W.; Kupsc, A.; Lai, W.; Lange, J. S.; Lara, M.; Larin, P.; Leyhe, M.; Li, C. H.; Li, Cheng; Li, Cui; Li, D.; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, K.; Li, K.; Li, Lei; Li, P. R.; Li, Q. J.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, X. R.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Lin, D. X.; Liu, B. J.; Liu, C. L.; Liu, C. X.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. P.; Liu, K.; Liu, K. Y.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H.; Lou, X. C.; Lu, G. R.; Lu, H. J.; Lu, H. L.; Lu, J. G.; Lu, X. R.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lv, M.; Ma, F. C.; Ma, H. L.; Ma, Q. M.; Ma, S.; Ma, T.; Ma, X. Y.; Maas, F. E.; Maggiora, M.; Malik, Q. A.; Mao, Y. J.; Mao, Z. P.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Moeini, H.; Morales, C. Morales; Moriya, K.; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Prencipe, E.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, X. S.; Qin, Y.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Ripka, M.; Rong, G.; Ruan, X. D.; Sarantsev, A.; Schoenning, K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C. P.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, W. M.; Song, X. Y.; Spataro, S.; Spruck, B.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Toth, D.; Ullrich, M.; Uman, I.; Varner, G. S.; Wang, B.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q. J.; Wang, S. G.; Wang, W.; Wang, X. F.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Wei, D. H.; Wei, J. B.; Weidenkaff, P.; Wen, S. P.; Werner, M.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, N.; Wu, W.; Wu, Z.; Xia, L. G.; Xia, Y.; Xiao, D.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, L.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Xue, Z.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. X.; Yang, Y.; Yang, Y. X.; Ye, H.; Ye, M.; Ye, M. H.; Yu, B. X.; Yu, C. X.; Yu, H. W.; Yu, J. S.; Yu, S. P.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Zafar, A. A.; Zallo, A.; Zang, S. L.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. B.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, S. H.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, X. H.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, Li; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.; Besiii Collaboration
2014-03-01
We report a measurement of the branching fraction B(D+→μ+νμ)=[3.71±0.19(stat)±0.06(sys)]×10-4 based on 2.92 fb-1 of data accumulated at √s =3.773 GeV with the BESIII detector at the BEPCII collider. This measurement, in conjunction with the Cabibbo-Kobayashi-Maskawa matrix element |Vcd| determined from a global Standard Model fit, implies a value for the weak decay constant fD+=(203.2±5.3±1.8) MeV. Additionally, using this branching fraction measurement together with a lattice QCD prediction for fD+, we find |Vcd|=0.2210±0.0058±0.0047. In either case, these are the most precise results for these quantities to date.
Aaltonen, T.; Brucken, E.; Devoto, F.; Mehtala, P.; Orava, R.; Alvarez Gonzalez, B.; Casal, B.; Gomez, G.; Palencia, E.; Rodrigo, T.; Ruiz, A.; Scodellaro, L.; Vila, I.; Vilar, R.; Amerio, S.; Dorigo, T.; Gresele, A.; Lazzizzera, I.; Amidei, D.; Campbell, M.
2010-12-17
A precision measurement of the top quark mass m{sub t} is obtained using a sample of tt events from pp collisions at the Fermilab Tevatron with the CDF II detector. Selected events require an electron or muon, large missing transverse energy, and exactly four high-energy jets, at least one of which is tagged as coming from a b quark. A likelihood is calculated using a matrix element method with quasi-Monte Carlo integration taking into account finite detector resolution and jet mass effects. The event likelihood is a function of m{sub t} and a parameter {Delta}{sub JES} used to calibrate the jet energy scale in situ. Using a total of 1087 events in 5.6 fb{sup -1} of integrated luminosity, a value of m{sub t}=173.0{+-}1.2 GeV/c{sup 2} is measured.
Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Apresyan, A.; Arisawa, T.; /Waseda U. /Dubna, JINR
2010-10-01
A precision measurement of the top quark mass m{sub t} is obtained using a sample of t{bar t} events from p{bar p} collisions at the Fermilab Tevatron with the CDF II detector. Selected events require an electron or muon, large missing transverse energy, and exactly four high-energy jets, at least one of which is tagged as coming from a b quark. A likelihood is calculated using a matrix element method with quasi-Monte Carlo integration taking into account finite detector resolution and jet mass effects. The event likelihood is a function of m{sub t} and a parameter {Delta}{sub JES} used to calibrate the jet energy scale in situ. Using a total of 1087 events, a value of m{sub t} = 173.0 {+-} 1.2 GeV/c{sup 2} is measured.
NASA Astrophysics Data System (ADS)
Aaltonen, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Apresyan, A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bauer, G.; Bedeschi, F.; Beecher, D.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Binkley, M.; Bisello, D.; Bizjak, I.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brau, B.; Brigliadori, L.; Brisuda, A.; Bromberg, C.; Brucken, E.; Bucciantonio, M.; Budagov, J.; Budd, H. S.; Budd, S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Calancha, C.; Camarda, S.; Campanelli, M.; Campbell, M.; Canelli, F.; Canepa, A.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chou, J. P.; Chung, W. H.; Chung, Y. S.; Ciobanu, C. I.; Ciocci, M. A.; Clark, A.; Compostella, G.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuenca Almenar, C.; Cuevas, J.; Culbertson, R.; Dagenhart, D.; D'Ascenzo, N.; Datta, M.; de Barbaro, P.; de Cecco, S.; de Lorenzo, G.; Dell'Orso, M.; Deluca, C.; Demortier, L.; Deng, J.; Deninno, M.; Devoto, F.; D'Errico, M.; di Canto, A.; di Ruzza, B.; Dittmann, J. R.; D'Onofrio, M.; Donati, S.; Dong, P.; Dorigo, T.; Ebina, K.; Elagin, A.; Eppig, A.; Erbacher, R.; Errede, D.; Errede, S.; Ershaidat, N.; Eusebi, R.; Fang, H. C.; Farrington, S.; Feindt, M.; Fernandez, J. P.; Ferrazza, C.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Furic, I.; Gallinaro, M.; Galyardt, J.; Garcia, J. E.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giunta, M.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gresele, A.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Gunay-Unalan, Z.; Haber, C.; Hahn, S. R.; Halkiadakis, E.; Hamaguchi, A.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harr, R. F.; Hatakeyama, K.; Hays, C.; Heck, M.; Heinrich, J.; Herndon, M.; Hewamanage, S.; Hidas, D.; Hocker, A.; Hopkins, W.; Horn, D.; Hou, S.; Hughes, R. E.; Hurwitz, M.; Husemann, U.; Hussain, N.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jha, M. K.; Jindariani, S.; Johnson, W.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kamon, T.; Karchin, P. E.; Kato, Y.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, H. W.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kimura, N.; Kirby, M.; Klimenko, S.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Krumnack, N.; Kruse, M.; Krutelyov, V.; Kuhr, T.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; Lazzizzera, I.; Lecompte, T.; Lee, E.; Lee, H. S.; Lee, J. S.; Lee, S. W.; Leo, S.; Leone, S.; Lewis, J. D.; Lin, C.-J.; Linacre, J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, Q.; Liu, T.; Lockwitz, S.; Lockyer, N. S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maeshima, K.; Makhoul, K.; Maksimovic, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Martínez, M.; Martínez-Ballarín, R.; Mastrandrea, P.; Mathis, M.; Mattson, M. E.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Menzione, A.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Mondragon, M. N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Movilla Fernandez, P.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Neubauer, M. S.; Nielsen, J.; Nodulman, L.; Norniella, O.; Nurse, E.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagan Griso, S.; Pagliarone, C.; Palencia, E.; Papadimitriou, V.; Paramonov, A. A.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Potamianos, K.; Poukhov, O.; Prokoshin, F.; Pronko, A.; Ptohos, F.; Pueschel, E.; Punzi, G.; Pursley, J.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Rossi, M.; Rubbo, F.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.; Sakumoto, W. K.; Santi, L.; Sartori, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, A.; Schmidt, E. E.; Schmidt, M. P.; Schmitt, M.; Schwarz, T.; Scodellaro, L.; Scribano, A.; Scuri, F.; Sedov, A.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Sfyrla, A.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shiraishi, S.; Shochet, M.; Shreyber, I.; Siegrist, J.; Simonenko, A.; Sinervo, P.; Sissakian, A.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Soha, A.; Somalwar, S.; Sorin, V.; Squillacioti, P.; Stanitzki, M.; Denis, R. St.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Strycker, G. L.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thome, J.; Thompson, G. A.; Thomson, E.; Ttito-Guzmán, P.; Tkaczyk, S.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Tu, Y.; Turini, N.; Ukegawa, F.; Uozumi, S.; Varganov, A.; Vataga, E.; Vázquez, F.; Velev, G.; Vellidis, C.; Vidal, M.; Vila, I.; Vilar, R.; Volobouev, I.; Vogel, M.; Volpi, G.; Wagner, P.; Wagner, R. L.; Wakisaka, T.; Wallny, R.; Wang, S. M.; Warburton, A.; Waters, D.; Weinberger, M.; Wester, W. C., III; Whitehouse, B.; Whiteson, D.; Wicklund, A. B.; Wicklund, E.; Wilbur, S.; Wick, F.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamaoka, J.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Yu, S. S.; Yun, J. C.; Zanetti, A.; Zeng, Y.; Zucchelli, S.
2010-12-01
A precision measurement of the top quark mass mt is obtained using a sample of tt¯ events from pp¯ collisions at the Fermilab Tevatron with the CDF II detector. Selected events require an electron or muon, large missing transverse energy, and exactly four high-energy jets, at least one of which is tagged as coming from a b quark. A likelihood is calculated using a matrix element method with quasi-Monte Carlo integration taking into account finite detector resolution and jet mass effects. The event likelihood is a function of mt and a parameter ΔJES used to calibrate the jet energy scale in situ. Using a total of 1087 events in 5.6fb-1 of integrated luminosity, a value of mt=173.0±1.2GeV/c2 is measured.
NASA Astrophysics Data System (ADS)
Aaltonen, T.; Adelman, J.; Akimoto, T.; González, B. Álvarez; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; Arisawa, T.; Artikov, A.; Ashmanskas, W.; Attal, A.; Aurisano, A.; Azfar, F.; Badgett, W.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartsch, V.; Bauer, G.; Beauchemin, P.-H.; Bedeschi, F.; Beecher, D.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Beringer, J.; Bhatti, A.; Binkley, M.; Bisello, D.; Bizjak, I.; Blair, R. E.; Blocker, C.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Boisvert, V.; Bolla, G.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brau, B.; Bridgeman, A.; Brigliadori, L.; Bromberg, C.; Brubaker, E.; Budagov, J.; Budd, H. S.; Budd, S.; Burke, S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Byrum, K. L.; Cabrera, S.; Calancha, C.; Campanelli, M.; Campbell, M.; Canelli, F.; Canepa, A.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chang, S. H.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chou, J. P.; Choudalakis, G.; Chuang, S. H.; Chung, K.; Chung, W. H.; Chung, Y. S.; Chwalek, T.; Ciobanu, C. I.; Ciocci, M. A.; Clark, A.; Clark, D.; Compostella, G.; Convery, M. E.; Conway, J.; Cordelli, M.; Cortiana, G.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Almenar, C. Cuenca; Cuevas, J.; Culbertson, R.; Cully, J. C.; Dagenhart, D.; Datta, M.; Davies, T.; de Barbaro, P.; de Cecco, S.; Deisher, A.; de Lorenzo, G.; Dell'Orso, M.; Deluca, C.; Demortier, L.; Deng, J.; Deninno, M.; Derwent, P. F.; di Canto, A.; di Giovanni, G. P.; Dionisi, C.; di Ruzza, B.; Dittmann, J. R.; D'Onofrio, M.; Donati, S.; Dong, P.; Donini, J.; Dorigo, T.; Dube, S.; Efron, J.; Elagin, A.; Erbacher, R.; Errede, D.; Errede, S.; Eusebi, R.; Fang, H. C.; Farrington, S.; Fedorko, W. T.; Feild, R. G.; Feindt, M.; Fernandez, J. P.; Ferrazza, C.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Furic, I.; Gallinaro, M.; Galyardt, J.; Garberson, F.; Garcia, J. E.; Garfinkel, A. F.; Garosi, P.; Genser, K.; Gerberich, H.; Gerdes, D.; Gessler, A.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Gimmell, J. L.; Ginsburg, C. M.; Giokaris, N.; Giordani, M.; Giromini, P.; Giunta, M.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gresele, A.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Grundler, U.; da Costa, J. Guimaraes; Gunay-Unalan, Z.; Haber, C.; Hahn, K.; Hahn, S. R.; Halkiadakis, E.; Han, B.-Y.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harper, S.; Harr, R. F.; Harris, R. M.; Hartz, M.; Hatakeyama, K.; Hays, C.; Heck, M.; Heijboer, A.; Heinrich, J.; Henderson, C.; Herndon, M.; Heuser, J.; Hewamanage, S.; Hidas, D.; Hill, C. S.; Hirschbuehl, D.; Hocker, A.; Hou, S.; Houlden, M.; Hsu, S.-C.; Huffman, B. T.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Incandela, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jha, M. K.; Jindariani, S.; Johnson, W.; Jones, M.; Joo, K. K.; Jun, S. Y.; Jung, J. E.; Junk, T. R.; Kamon, T.; Kar, D.; Karchin, P. E.; Kato, Y.; Kephart, R.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, H. W.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kimura, N.; Kirsch, L.; Klimenko, S.; Knuteson, B.; Ko, B. R.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Korytov, A.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Krumnack, N.; Kruse, M.; Krutelyov, V.; Kubo, T.; Kuhr, T.; Kulkarni, N. P.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; Lazzizzera, I.; Lecompte, T.; Lee, E.; Lee, H. S.; Lee, S. W.; Leone, S.; Lewis, J. D.; Lin, C.-S.; Linacre, J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, T.; Lockyer, N. S.; Loginov, A.; Loreti, M.; Lovas, L.; Lucchesi, D.; Luci, C.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lyons, L.; Lys, J.; Lysak, R.; MacQueen, D.; Madrak, R.; Maeshima, K.; Makhoul, K.; Maki, T.; Maksimovic, P.; Malde, S.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Marino, C. P.; Martin, A.; Martin, V.; Martínez, M.; Martínez-Ballarín, R.; Maruyama, T.; Mastrandrea, P.; Masubuchi, T.; Mathis, M.; Mattson, M. E.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Menzione, A.; Merkel, P.; Mesropian, C.; Miao, T.; Miladinovic, N.; Miller, R.; Mills, C.; Milnik, M.; Mitra, A.; Mitselmakher, G.; Miyake, H.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Fernandez, P. Movilla; Mülmenstädt, J.; Mukherjee, A.; Muller, Th.; Mumford, R.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Nagano, A.; Naganoma, J.; Nakamura, K.; Nakano, I.; Napier, A.; Necula, V.; Nett, J.; Neu, C.; Neubauer, M. S.; Neubauer, S.; Nielsen, J.; Nodulman, L.; Norman, M.; Norniella, O.; Nurse, E.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Osterberg, K.; Griso, S. Pagan; Palencia, E.; Papadimitriou, V.; Papaikonomou, A.; Paramonov, A. A.; Parks, B.; Pashapour, S.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Peiffer, T.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pinera, L.; Pitts, K.; Plager, C.; Pondrom, L.; Poukhov, O.; Pounder, N.; Prakoshyn, F.; Pronko, A.; Proudfoot, J.; Ptohos, F.; Pueschel, E.; Punzi, G.; Pursley, J.; Rademacker, J.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Renz, M.; Rescigno, M.; Richter, S.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Rossi, M.; Rossin, R.; Roy, P.; Ruiz, A.; Russ, J.; Rusu, V.; Rutherford, B.; Saarikko, H.; Safonov, A.; Sakumoto, W. K.; Saltó, O.; Santi, L.; Sarkar, S.; Sartori, L.; Sato, K.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, A.; Schmidt, E. E.; Schmidt, M. A.; Schmidt, M. P.; Schmitt, M.; Schwarz, T.; Scodellaro, L.; Scribano, A.; Scuri, F.; Sedov, A.; Seidel, S.; Seiya, Y.; Semenov, A.; Sexton-Kennedy, L.; Sforza, F.; Sfyrla, A.; Shalhout, S. Z.; Shears, T.; Shekhar, R.; Shepard, P. F.; Shimojima, M.; Shiraishi, S.; Shochet, M.; Shon, Y.; Shreyber, I.; Sinervo, P.; Sisakyan, A.; Slaughter, A. J.; Slaunwhite, J.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Snihur, R.; Soha, A.; Somalwar, S.; Sorin, V.; Spreitzer, T.; Squillacioti, P.; Stanitzki, M.; St. Denis, R.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Strycker, G. L.; Suh, J. S.; Sukhanov, A.; Suslov, I.; Suzuki, T.; Taffard, A.; Takashima, R.; Takeuchi, Y.; Tanaka, R.; Tecchio, M.; Teng, P. K.; Terashi, K.; Thom, J.; Thompson, A. S.; Thompson, G. A.; Thomson, E.; Tipton, P.; Ttito-Guzmán, P.; Tkaczyk, S.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Tourneur, S.; Trovato, M.; Tsai, S.-Y.; Tu, Y.; Turini, N.; Ukegawa, F.; Vallecorsa, S.; van Remortel, N.; Varganov, A.; Vataga, E.; Vázquez, F.; Velev, G.; Vellidis, C.; Vidal, M.; Vidal, R.; Vila, I.; Vilar, R.; Vine, T.; Vogel, M.; Volobouev, I.; Volpi, G.; Wagner, P.; Wagner, R. G.; Wagner, R. L.; Wagner, W.; Wagner-Kuhr, J.; Wakisaka, T.; Wallny, R.; Wang, S. M.; Warburton, A.; Waters, D.; Weinberger, M.; Weinelt, J.; Wester, W. C., III; Whitehouse, B.; Whiteson, D.; Wicklund, A. B.; Wicklund, E.; Wilbur, S.; Williams, G.; Williams, H. H.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, C.; Wright, T.; Wu, X.; Würthwein, F.; Xie, S.; Yagil, A.; Yamamoto, K.; Yamaoka, J.; Yang, U. K.; Yang, Y. C.; Yao, W. M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Yu, S. S.; Yun, J. C.; Zanello, L.; Zanetti, A.; Zhang, X.; Zheng, Y.; Zucchelli, S.
2009-10-01
We present a search for associated production of the standard model Higgs boson and a Z boson where the Z boson decays to two leptons and the Higgs decays to a pair of b quarks in pp¯ collisions at the Fermilab Tevatron. We use event probabilities based on standard model matrix elements to construct a likelihood function of the Higgs content of the data sample. In a CDF data sample corresponding to an integrated luminosity of 2.7fb-1 we see no evidence of a Higgs boson with a mass between 100GeV/c2 and 150GeV/c2. We set 95% confidence level upper limits on the cross section for ZH production as a function of the Higgs boson mass mH; the limit is 8.2 times the standard model prediction at mH=115GeV/c2.
NASA Astrophysics Data System (ADS)
Basye, Austin T.
A matrix element method analysis of the Standard Model Higgs boson, produced in association with two top quarks decaying to the lepton-plus-jets channel is presented. Based on 20.3 fb--1 of s=8 TeV data, produced at the Large Hadron Collider and collected by the ATLAS detector, this analysis utilizes multiple advanced techniques to search for ttH signatures with a 125 GeV Higgs boson decaying to two b -quarks. After categorizing selected events based on their jet and b-tag multiplicities, signal rich regions are analyzed using the matrix element method. Resulting variables are then propagated to two parallel multivariate analyses utilizing Neural Networks and Boosted Decision Trees respectively. As no significant excess is found, an observed (expected) limit of 3.4 (2.2) times the Standard Model cross-section is determined at 95% confidence, using the CLs method, for the Neural Network analysis. For the Boosted Decision Tree analysis, an observed (expected) limit of 5.2 (2.7) times the Standard Model cross-section is determined at 95% confidence, using the CLs method. Corresponding unconstrained fits of the Higgs boson signal strength to the observed data result in the measured signal cross-section to Standard Model cross-section prediction of mu = 1.2 +/- 1.3(total) +/- 0.7(stat.) for the Neural Network analysis, and mu = 2.9 +/- 1.4(total) +/- 0.8(stat.) for the Boosted Decision Tree analysis.
Hsieh, Hui-Fang; Chen, Yi-Hsiang; Wang, Chu-Fang
2011-08-15
This paper describes a simple method for simultaneous preconcentration and matrix reduction during the analysis of rare earth elements (REEs) in water samples through laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). From a systematic investigation of the co-precipitation of REEs using magnesium hydroxide, we optimized the effects of several parameters - the pH, the amount of magnesium, the shaking time, the efficiency of Ba removal, and the sample matrix - to ensure quantitative recoveries. We employed repetitive laser ablation to remove the dried-droplet samples from the filter medium and introduce them into the ICP-MS system for determinations of REEs. The enrichment factors ranged from 8 to 88. The detection limit, at an enrichment factor of 32, ranged from 0.03 to 0.20 pg mL(-1). The relative standard deviations for the determination of REEs at a concentration of 1 ng mL(-1) when processing 40 mL sample solution were 2.0-4.8%. We applied this method to the satisfactory determination of REEs in lake water and synthetic seawater samples.
NASA Technical Reports Server (NTRS)
Ko, William L.
1995-01-01
Thermal buckling characteristics of hypersonic aircraft sandwich panels of various aspect ratios were investigated. The panel is fastened at its four edges to the substructures under four different edge conditions and is subjected to uniform temperature loading. Minimum potential energy theory and finite element methods were used to calculate the panel buckling temperatures. The two methods gave fairly close buckling temperatures. However, the finite element method gave slightly lower buckling temperatures than those given by the minimum potential energy theory. The reasons for this slight discrepancy in eigensolutions are discussed in detail. In addition, the effect of eigenshifting on the eigenvalue convergence rate is discussed.
Ekwueme, Emmanuel C.; Shah, Jay V.; Mohiuddin, Mahir; Ghebes, Corina A.; Crispim, João F.; Saris, Daniël B.F.; Fernandes, Hugo A.M.; Freeman, Joseph W.
2016-01-01
Tendon and ligament (T/L) pathologies account for a significant portion of musculoskeletal injuries and disorders. Tissue engineering has emerged as a promising solution in the regeneration of both tissues. Specifically, the use of multipotent human mesenchymal stromal cells (hMSC) has shown great promise to serve as both a suitable cell source for tenogenic regeneration and a source of trophic factors to induce tenogenesis. Using four donor sets, we investigated the bidirectional paracrine tenogenic response between human hamstring tenocytes (hHT) and bone marrow-derived hMSC. Cell metabolic assays showed that only one hHT donor experienced sustained notable increases in cell metabolic activity during co-culture. Histological staining confirmed that co-culture induced elevated collagen protein levels in both cell types at varying time-points in two of four donor sets assessed. Gene expression analysis using qPCR showed the varied up-regulation of anabolic and catabolic markers involved in extracellular matrix maintenance for hMSC and hHT. Furthermore, analysis of hMSC/hHT co-culture secretome using a reporter cell line for TGF-β, a potent inducer of tenogenesis, revealed a trend of higher TGF-β bioactivity in hMSC secretome compared to hHT. Finally, hHT cytoskeletal immunostaining confirmed that both cell types released soluble factors capable of inducing favorable tenogenic morphology, comparable to control levels of soluble TGF-β1. These results suggest a potential for TGF-β-mediated signaling mechanism that is involved during the paracrine interplay between the two cell types that is reminiscent of T/L matrix remodeling/ turnover. These findings have significant implications in the clinical use of hMSC for common T/L pathologies. PMID:26308651
Patchsung, Maturada; Boonla, Chanchai; Amnattrakul, Passakorn; Dissayabutra, Thasinas; Mutirangura, Apiwat; Tosukhowong, Piyaratana
2012-01-01
Although, increased oxidative stress and hypomethylation of long interspersed nuclear element-1 (LINE-1) associate with bladder cancer (BCa) development, the relationship between these alterations is unknown. We evaluated the oxidative stress and hypomethylation of the LINE-1 in 61 BCa patients and 45 normal individuals. To measure the methylation levels and to differentiate the LINE-1 loci into hypermethylated, partially methylated and hypomethylated, peripheral blood cells, urinary exfoliated cells and cancerous tissues were evaluated by combined bisulfite restriction analysis PCR. The urinary total antioxidant status (TAS) and plasma protein carbonyl content were determined. The LINE-1 methylation levels and patterns, especially hypomethylated loci, in the blood and urine cells of the BCa patients were different from the levels and patterns in the healthy controls. The urinary TAS was decreased, whereas the plasma protein carbonyl content was increased in the BCa patients relative to the controls. A positive correlation between the methylation of LINE-1 in the blood-derived DNA and urinary TAS was found in both the BCa and control groups. The urinary hypomethylated LINE-1 loci and the plasma protein carbonyl content provided the best diagnostic potential for BCa prediction. Based on post-diagnostic samples, the combination test improved the diagnostic power to a sensitivity of 96% and a specificity of 96%. In conclusion, decreased LINE-1 methylation is associated with increased oxidative stress both in healthy and BCa subjects across the various tissue types, implying a dose-response association. Increases in the LINE-1 hypomethylation levels and the number of hypomethylated loci in both the blood- and urine-derived cells and increase in the oxidative stress were found in the BCa patients. The combination test of the urinary hypomethylated LINE-1 loci and the plasma protein carbonyl content may be useful for BCa screening and monitoring of treatment.
Domínguez, María T; Montiel-Rozas, María M; Madejón, Paula; Diaz, Manuel J; Madejón, Engracia
2017-03-10
The establishment of energy crops could be an option for the management of degraded and contaminated lands, where they would not compete with food production for land use. Here, we aimed to explore the potential of certain native Mediterranean species for the revegetation of contaminated lands for energy production purposes. A field survey was conducted in a trace-element (TE) contaminated area from SW Spain, where the patterns of biomass production, TE accumulation and the calorific value of some thistle species were analyzed along a soil contamination gradient. In a greenhouse experiment the response of two thistle species (Cynara cardunculus and Silybum marianum) and the shrub Dittrichia viscosa to soil contamination was assessed, as well as the effects of these species on some soil microbial parameters involved in nutrient cycling (enzyme activities and arbuscular mycorrhizal colonization in roots). Silybum marianum was able to colonize highly contaminated soils. Its aboveground biomass accumulated Cd and had a relatively high calorific value; this value was similar in biomass obtained from both heavily and moderately contaminated soils. Greenhouse experiment confirmed that S. marianum biomass production and calorific value is scarcely affected by soil contamination. In addition, some soil enzyme activities were clearly enhanced in the S. marianum rhizosphere. Dittrichia viscosa is another promising species, given its capacity to produce a high biomass with appreciable calorific value in acid contaminated soils. Germination of both species was hampered in the acid contaminated soil, and therefore soil pH correction would have to be accomplished before establishing these species on extremely acid soils. Further assessment of the risk of transfer of Cd and other TE to the food chain would be needed to confirm the suitability of these species for the revegetation of contaminated lands with energy production purposes.
NASA Astrophysics Data System (ADS)
Smith, F.
2013-12-01
This paper will examine the use of a specialized low-flow desolvating nebulizer system for reduction of oxide mass spectral interferences that can occur in quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS). This nebulizer system uses an inert low-flow nebulizer (100 microliters/min) coupled to an inert, heated membrane desolvator for efficient water vapor removal before sample aerosol injection to the Q-ICP-MS instrument. Water vapor from conventional nebulizer / spray chamber systems used with Q-ICP-MS can cause numerous mass spectral interferences. One general example is metal oxides formed from the combination of oxygen (from injected water) with sample matrix components. Two specific examples of metal oxide interferences will be investigated with and without membrane desolvation: Ba and Ce oxides on several low-mass rare earth elements (Sm, Eu, and Gd) and Hf oxides on platinum. Rare earth elements are critically important components of modern electronics (ex. magnets, lasers, cell phones, computers) and platinum is a widely used catalyst. Figures of merit for both a conventional nebulizer/spray chamber and the desolvating nebulizer systems will include operating conditions, interference intensities and reduction factors, background equivalent concentrations (BECs), and instrument detection limits (IDLs).
Dong, Xingjian; Peng, Zhike; Hua, Hongxing; Meng, Guang
2014-01-01
An efficient spectral element (SE) with electric potential degrees of freedom (DOF) is proposed to investigate the static electromechanical responses of a piezoelectric bimorph for its actuator and sensor functions. A sublayer model based on the piecewise linear approximation for the electric potential is used to describe the nonlinear distribution of electric potential through the thickness of the piezoelectric layers. An equivalent single layer (ESL) model based on first-order shear deformation theory (FSDT) is used to describe the displacement field. The Legendre orthogonal polynomials of order 5 are used in the element interpolation functions. The validity and the capability of the present SE model for investigation of global and local responses of the piezoelectric bimorph are confirmed by comparing the present solutions with those obtained from coupled 3-D finite element (FE) analysis. It is shown that, without introducing any higher-order electric potential assumptions, the current method can accurately describe the distribution of the electric potential across the thickness even for a rather thick bimorph. It is revealed that the effect of electric potential is significant when the bimorph is used as sensor while the effect is insignificant when the bimorph is used as actuator, and therefore, the present study may provide a better understanding of the nonlinear induced electric potential for bimorph sensor and actuator. PMID:24561399
Shekhar, R.; Karunasagar, D.; Ranjit, M.; Arunachalam, J.
2009-10-15
An open-to-air type electrolyte cathode discharge (ELCAD) has been developed with a new design. The present configuration leads to a stable plasma even at low flow rates (0.96 mL/min). Plasma fluctuations arising from the variations in the gap between solid anode and liquid cathode were eliminated by providing a V-groove to the liquid glass-capillary. Cathode (ground) connection is given to the solution at the V-groove itself. Interfaced to atomic emission spectrometry (AES), its analytical performance is evaluated. The optimized molarity of the solution is 0.2 M. The analytical response curves for Ca, Cu, Cd, Pb, Hg, Fe, and Zn demonstrated good linearity. The limit of detections of Ca, Cu, Cd, Pb, Hg, Fe, and Zn are determined to be 17, 11, 5, 45, 15, 28, and 3 ng mL{sup -1}. At an integration time of 0.3 s, the relative standard deviation (RSD) values of the acid blank solutions are found to be less than 10% for the elements Ca, Cu, Cd, Hg, Fe, and Zn and 18% for Pb. The method is applied for the determination of the elemental constituents in different matrix materials such as tuna fish (IAEA-350), oyster tissue (NIST SRM 1566a), and coal fly ash (CFA SRM 1633b). The obtained results are in good agreement with the certified values. The accuracy is found to be between 7% and 0.6% for major to trace levels of constituent elements and the precision between 11% and 0.6%. For the injection of 100 {mu} L of 200 ng mL{sup -1} mercury solution at the flow rate of 0.8 mL/min, the flow injection studies resulted in the relative standard deviation (RSD) of 8%, concentration detection limit of 10 ng/mL, and mass detection limit of 1 ng for mercury.
Transposable elements as a potential source for understanding the fish genome
Porto-Foresti, Fabio; Oliveira, Claudio; Foresti, Fausto
2011-01-01
Transposable elements are repetitive sequences with the capacity tomove inside of the genome. They constitute the majority of the eukaryotic genomes, and are extensively present in the human genome, representing more than 45% of the genome sequences. The knowledge of the origin and function of these elements in the fish genome is still reduced and fragmented, mainly with regard to its structure and organization in the chromosomes of the representatives of this biological group, with data currently available for very few species that represent the great variety of forms and existing diversity. Comparative analyses ascertain differences in the organization of such elements in the species studied up to the present. They can be part of the heterochromatic regions in some species or be spread throughout the genome in others. The main objective of the present revision is to discuss the aspects of the organization of transposable elements in the fish genome. PMID:22016858
Clarkin, C E; Allen, S; Wheeler-Jones, C P; Bastow, E R; Pitsillides, A A
2011-04-01
4-Methylumbelliferone (4-MU) is described as a selective inhibitor of hyaluronan (HA) production. It is thought that 4-MU depletes UDP-glucuronic acid (UDP-GlcUA) substrate for HA synthesis and also suppresses HA-synthase expression. The possibility that 4-MU exerts at least some of its actions via regulation of UDP-glucose dehydrogenase (UGDH), a key enzyme required for both HA and sulphated-glycosaminoglycan (sGAG) production, remains unexplored. We therefore examined the effects of 4-MU on basal and retroviral UGDH-driven HA and sGAG release in cells derived from chick articular cartilage and its influence upon UGDH protein and mRNA expression and HA and sGAG production. We found that 4-MU: i) suppressed UGDH mRNA and protein expression and chondrogenic matrix accumulation in chick limb bud micromass culture, ii) significantly reduced both HA and sGAG production and iii) more selectively reversed the potentiating effects of UGDH overexpression on the production of HA than sGAG. Understanding how GAG synthesis is controlled and the mechanism of 4-MU action may inform its future clinical success.
Clarkin, C.E.; Allen, S.; Wheeler-Jones, C.P.; Bastow, E.R.; Pitsillides, A.A.
2011-01-01
4-Methylumbelliferone (4-MU) is described as a selective inhibitor of hyaluronan (HA) production. It is thought that 4-MU depletes UDP-glucuronic acid (UDP-GlcUA) substrate for HA synthesis and also suppresses HA-synthase expression. The possibility that 4-MU exerts at least some of its actions via regulation of UDP-glucose dehydrogenase (UGDH), a key enzyme required for both HA and sulphated-glycosaminoglycan (sGAG) production, remains unexplored. We therefore examined the effects of 4-MU on basal and retroviral UGDH-driven HA and sGAG release in cells derived from chick articular cartilage and its influence upon UGDH protein and mRNA expression and HA and sGAG production. We found that 4-MU: i) suppressed UGDH mRNA and protein expression and chondrogenic matrix accumulation in chick limb bud micromass culture, ii) significantly reduced both HA and sGAG production and iii) more selectively reversed the potentiating effects of UGDH overexpression on the production of HA than sGAG. Understanding how GAG synthesis is controlled and the mechanism of 4-MU action may inform its future clinical success. PMID:21292001
Crispi, Stefania; Calogero, Raffaele A.; Santini, Mario; Mellone, Pasquale; Vincenzi, Bruno; Citro, Gennaro; Vicidomini, Giovanni; Fasano, Silvia; Meccariello, Rosaria; Cobellis, Gilda; Menegozzo, Simona; Pierantoni, Riccardo; Facciolo, Francesco; Baldi, Alfonso; Menegozzo, Massimo
2009-01-01
Background The goal of our study was to molecularly dissect mesothelioma tumour pathways by mean of microarray technologies in order to identify new tumour biomarkers that could be used as early diagnostic markers and possibly as specific molecular therapeutic targets. Methodology We performed Affymetrix HGU133A plus 2.0 microarray analysis, containing probes for about 39,000 human transcripts, comparing 9 human pleural mesotheliomas with 4 normal pleural specimens. Stringent statistical feature selection detected a set of differentially expressed genes that have been further evaluated to identify potential biomarkers to be used in early diagnostics. Selected genes were confirmed by RT-PCR. As reported by other mesothelioma profiling studies, most of genes are involved in G2/M transition. Our list contains several genes previously described as prognostic classifier. Furthermore, we found novel genes, never associated before to mesotheliom that could be involved in tumour progression. Notable is the identification of MMP-14, a member of matrix metalloproteinase family. In a cohort of 70 mesothelioma patients, we found by a multivariate Cox regression analysis, that the only parameter influencing overall survival was expression of MMP14. The calculated relative risk of death in MM patients with low MMP14 expression was significantly lower than patients with high MMp14 expression (P = 0.002). Conclusions Based on the results provided, this molecule could be viewed as a new and effective therapeutic target to test for the cure of mesothelioma. PMID:19753302
Szepesi, Zsuzsanna; Bijata, Monika; Ruszczycki, Blazej; Kaczmarek, Leszek; Wlodarczyk, Jakub
2013-01-01
Dendritic spines are are small membranous protrusions that extend from neuronal dendrites and harbor the majority of excitatory synapses. Increasing evidence has shown that matrix metalloproteinases (MMPs), a family of extracellularly acting and Zn2+-dependent endopeptidases, are able to rapidly modulate dendritic spine morphology. Spine head protrusions (SHPs) are filopodia-like processes that extend from the dendritic spine head, representing a form of postsynaptic structural remodeling in response to altered neuronal activity. Herein, we show that chemically induced long-term potentiation (cLTP) in dissociated hippocampal cultures upregulates MMP-9 activity that controls the formation of SHPs. Blocking of MMPs activity or microtubule dynamics abolishes the emergence of SHPs. In addition, autoactive recombinant MMP-9, promotes the formation of SHPs in organotypic hippocampal slices. Furthermore, spines with SHPs gained postsynaptic α-amino-3-hydroxyl-5-methyl-4-isoxazole propionic acid (AMPA) receptors upon cLTP and the synaptic delivery of AMPA receptors was controlled by MMPs. The present results strongly imply that MMP-9 is functionally involved in the formation of SHPs and the control of postsynaptic receptor distribution upon cLTP. PMID:23696812
Qazi, Henry; Shi, Zhong-Dong; Tarbell, John M.
2011-01-01
Background Glioma cells are exposed to elevated interstitial fluid flow during the onset of angiogenesis, at the tumor periphery while invading normal parenchyma, within white matter tracts, and during vascular normalization therapy. Glioma cell lines that have been exposed to fluid flow forces in vivo have much lower invasive potentials than in vitro cell motility assays without flow would indicate. Methodology/Principal Findings A 3D Modified Boyden chamber (Darcy flow through collagen/cell suspension) model was designed to mimic the fluid dynamic microenvironment to study the effects of fluid shear stress on the migratory activity of glioma cells. Novel methods for gel compaction and isolation of chemotactic migration from flow stimulation were utilized for three glioma cell lines: U87, CNS-1, and U251. All physiologic levels of fluid shear stress suppressed the migratory activity of U87 and CNS-1 cell lines. U251 motility remained unaltered within the 3D interstitial flow model. Matrix Metalloproteinase (MMP) inhibition experiments and assays demonstrated that the glioma cells depended on MMP activity to invade, and suppression in motility correlated with downregulation of MMP-1 and MMP-2 levels. This was confirmed by RT-PCR and with the aid of MMP-1 and MMP-2 shRNA constructs. Conclusions/Significance Fluid shear stress in the tumor microenvironment may explain reduced glioma invasion through modulation of cell motility and MMP levels. The flow-induced migration trends were consistent with reported invasive potentials of implanted gliomas. The models developed for this study imply that flow-modulated motility involves mechanotransduction of fluid shear stress affecting MMP activation and expression. These models should be useful for the continued study of interstitial flow effects on processes that affect tumor progression. PMID:21637818
NASA Technical Reports Server (NTRS)
Baumeister, Kenneth J.; Baumeister, Joseph F.
1994-01-01
An analytical procedure is presented, called the modal element method, that combines numerical grid based algorithms with eigenfunction expansions developed by separation of variables. A modal element method is presented for solving potential flow in a channel with two-dimensional cylindrical like obstacles. The infinite computational region is divided into three subdomains; the bounded finite element domain, which is characterized by the cylindrical obstacle and the surrounding unbounded uniform channel entrance and exit domains. The velocity potential is represented approximately in the grid based domain by a finite element solution and is represented analytically by an eigenfunction expansion in the uniform semi-infinite entrance and exit domains. The calculated flow fields are in excellent agreement with exact analytical solutions. By eliminating the grid surrounding the obstacle, the modal element method reduces the numerical grid size, employs a more precise far field boundary condition, as well as giving theoretical insight to the interaction of the obstacle with the mean flow. Although the analysis focuses on a specific geometry, the formulation is general and can be applied to a variety of problems as seen by a comparison to companion theories in aeroacoustics and electromagnetics.
Heroult, Julien; Nischwitz, Volker; Bartczak, Dorota; Goenaga-Infante, Heidi
2014-06-01
This work represents a first systematic approach to the size-based elemental quantification and size estimation of metal(loid) oxide nanoparticles such as silica (SiO2) in a real food matrix using asymmetric flow field-flow fractionation coupled online with inductively coupled plasma mass spectrometry (ICP-MS) and multi-angle light scattering (MALS) and offline with transmission electron microscopy (TEM) with energy-dispersive X-ray analysis (EDAX). Coffee creamer was selected as the model sample since it is known to contain silica as well as metal oxides such as titania at the milligramme per kilogramme levels. Optimisation of sample preparation conditions such as matrix-to-solvent ratio, defatting with organic solvents and sonication time that may affect nanoparticle size and size distribution in suspensions was investigated. Special attention was paid to the selection of conditions that minimise particle transformation during sample preparation and analysis. The coffee creamer matrix components were found to stabilise food grade SiO2 particles in comparison with water suspensions whilst no significant effect of defatting using hexane was found. The use of sample preparation procedures that mimic food cooking in real life was also investigated regarding their effect on particle size and particle size distribution of silica nanoparticles in the investigated food matrix; no significant effect of the water temperature ranging from ambient temperature to 60 °C was observed. Field-flow fractionation coupled to inductively coupled plasma-mass spectrometry (FFF-ICP-MS) analysis of extracts of both unspiked coffee creamer and coffee creamer spiked with food grade silicon dioxide, using different approaches for size estimation, enabled determination of SiO2 size-based speciation. Element-specific detection by ICP-MS and post-FFF calibration with elemental calibration standards was used to determine the elemental composition of size fractions separated online by FFF
Matsumura, Mai; Okudela, Koji; Kojima, Yoko; Umeda, Shigeaki; Tateishi, Yoko; Sekine, Akimasa; Arai, Hiromasa; Woo, Tetsukan; Tajiri, Michihiko; Ohashi, Kenichi
2016-01-01
The purpose of this study was to define histological features determining the malignant potential of EGFR-mutated lung adenocarcinoma (LADC). Surgically resected tumors (EGFR-mutated LADCs with (21) and without (79) lymph node metastasis and EGFR wild-type LADCs with (26) and without (108) lymph node metastasis) and biopsy samples from inoperably advanced tumors (EGFR-mutated LADCs (78) and EGFR wild-type LADCs (99)) were examined. In surgically resected tumors, the EGFR-mutated LADCs with lymph node metastasis had the micropapillary element in a significantly greater proportion than others (Mann-Whitney tests P ≤0.026). The proportion of micropapillary element was higher in the EGFR-mutated LADC at the advanced stage (stage II, III, or IV) than in the tumor at the early stage (stage I) (Mann-Whitney test, P<0.0001). In the biopsy samples from inoperably advanced LADCs (177), EGFR-mutated tumors also had micropapillary element at a higher frequency than EGFR-wild type tumors (53/78 (68%), versus 30/99 (30%), Pearson x2 test, P<0.0001). In stage I EGFR-mutated LADCs (84), the tumors with the micropapillary element (34) exhibited a significantly higher recurrence rate than tumors without micropapillary element (50) (5-year Recurrence-free survival 64.4% versus 93.3%, log-rank test P = 0.028). The micropapillary element may be an exclusive determinant of malignant potential in EGFR-mutated LADC. It is suggested that EGFR-mutated LADC may develop through a distinct histogenesis, in which the micropapillary element is important for promoting progression. PMID:27861549
Szenes, Aron; Pál, Gábor
2012-06-01
The recently published discrete mathematical method, extended consensus partition (ECP), identifies nucleotide types at each position that are strictly absent from a given sequence set, while occur in other sets. These are defined as discriminating elements (DEs). In this study using the ECP approach, we mapped potential hidden identity elements that discriminate the 20 different tRNA identities. We filtered the tDNA data set for the obligatory presence of well-established tRNA features, and then separately for each identity set, the presence of already experimentally identified strictly present identity elements. The analysis was performed on the three kingdoms of life. We determined the number of DE, e.g. the number of sets discriminated by the given position, for each tRNA position of each tRNA identity set. Then, from the positional DE numbers obtained from the 380 pairwise comparisons of the 20 identity sets, we calculated the average excluding value (AEV) for each tRNA position. The AEV provides a measure on the overall discriminating power of each position. Using a statistical analysis, we show that positional AEVs correlate with the number of already identified identity elements. Positions having high AEV but lacking published identity elements predict hitherto undiscovered tRNA identity elements.
Szenes, Áron; Pál, Gábor
2012-01-01
The recently published discrete mathematical method, extended consensus partition (ECP), identifies nucleotide types at each position that are strictly absent from a given sequence set, while occur in other sets. These are defined as discriminating elements (DEs). In this study using the ECP approach, we mapped potential hidden identity elements that discriminate the 20 different tRNA identities. We filtered the tDNA data set for the obligatory presence of well-established tRNA features, and then separately for each identity set, the presence of already experimentally identified strictly present identity elements. The analysis was performed on the three kingdoms of life. We determined the number of DE, e.g. the number of sets discriminated by the given position, for each tRNA position of each tRNA identity set. Then, from the positional DE numbers obtained from the 380 pairwise comparisons of the 20 identity sets, we calculated the average excluding value (AEV) for each tRNA position. The AEV provides a measure on the overall discriminating power of each position. Using a statistical analysis, we show that positional AEVs correlate with the number of already identified identity elements. Positions having high AEV but lacking published identity elements predict hitherto undiscovered tRNA identity elements. PMID:22378766
Rzymski, Piotr; Mleczek, Mirosław; Niedzielski, Przemysław; Siwulski, Marek; Gąsecka, Monika
2016-03-01
Ganoderma lucidum is an important medicinal mushroom species and there is continuous interest in its bioactive properties. This study evaluated whether it may additionally serve as a nutritional supplement for the trace elements: selenium (Se), copper (Cu), and zinc (Zn). Mushrooms were cultivated on substrates enriched with 0.1 to 0.8 mM of inorganic Se alone or in combination with Zn and/or Cu. Supplementation increased accumulation of the elements in fruiting bodies regardless of the applied cultivation model. G. lucidum demonstrated the ability to accumulate significant amounts of organic Se, maximally amounting to (i) over 44 mg/kg when the substrate was supplemented only with Se, (ii) over 20 mg/kg in the Se+Cu model, (iii) over 25 mg/kg in the Se+Zn model, and (iv) 15 mg/kg in the Se+Cu+Zn model. The accumulation of Cu and Zn steadily increased with their initial substrate concentrations. Maximum concentrations found after supplementation with 0.8 mM amounted to over 55 mg/kg (Se+Zn) and 52 mg/kg (Se+Cu+Zn) of Zn, and 29 mg/kg (Se+Cu) and over 31 mg/kg (Se+Cu+Zn) of Cu. The greater the supplemented concentration and number of supplemented elements, the lower the biomass of G. lucidum fruiting bodies. Nevertheless, it still remained high when the substrate was supplemented up to 0.4 mM with each element. These results highlight that G. lucidum can easily incorporate elements from the substrate and that, when biofortified, its dried fruiting bodies may serve as a nutritional source of these essential elements.
Chang, Zhiwei; Li, Jiguang; Dong, Chenzhong
2010-12-30
Multiconfiguration Dirac-Fock (MCDF) method was employed to calculate the first five ionization potentials, electron affinities, resonance excitation energies, oscillator strengths, and radii for the element Uus and its homologue At. Main valence correlation effects were taken into account. The Breit interaction and QED effects were also estimated. The uncertainties of calculated IPs, EAs, and IR for Uus and At were reduced through an extrapolation procedure. The good consistency with available experimental and other theoretical values demonstrates the validity of the present results. These theoretical data therefore can be used to predict some unknown physicochemical properties of element Uus, Astatine, and their compounds.
NASA Astrophysics Data System (ADS)
Capper, P.; O'Keefe, E. S.; Maxey, C.; Dutton, D.; Mackett, P.; Butler, C.; Gale, I.
1996-04-01
This review describes several of the main techniques used to determine matrix element distributions and those which can provide a survey of impurity levels and assess deliberate doping concentrations in Cd xHg 1 - xTe and CdTe-based substrate materials. The most widely used method to non-destructively determine x is that of Fourier transform infrared (FTIR) spectrometry and lateral x variations in current bulk, LPE and MOVPE material measured by this technique will be presented. Auger electron spectrometry (AES) has been used on bevelled samples to assess variations in x with depth and interface widths in LPE, MOVPE and MBE layers and examples will be given. Near IR spectrometry is also now being used to monitor the variations in Zn and Se content, in CdZnTe and CdTeSe respectively, and results in this area will be described along with measurements of Zn on the micro-scale using AES. All of these techniques need to be calibrated against an absolute chemical analysis technique and we have used atomic absorption spectrometry (AAS). The latter technique also provides the accurate measure of dopant and impurity elements to standardise other techniques. Secondary ion mass spectrometry (SIMS) is mainly used for the determination of dopant depth distributions while laser scan mass spectrometry (LSMS) has the unique capability of providing a survey of low levels of impurities in thin epitaxial layers. Depth profiles of arsenic and iodine in MOVPE heterostructures, using SIMS, will be given. Impurity surveys, using LSMS, in bulk CMT and substrate materials and in CMT epitaxial layers grown by LPE, MOVPE and MBE will be described. Reported glow discharge mass spectrometry (GDMS) results on substrate materials will be compared to the present results.
Volkmann, Bethany A.; Zinkevich, Natalya S.; Mustonen, Aki; Schilter, Kala F.; Bosenko, Dmitry V.; Reis, Linda M.; Broeckel, Ulrich; Link, Brian A.
2011-01-01
Purpose. Mutations in PITX2 are associated with Axenfeld-Rieger syndrome (ARS), which involves ocular, dental, and umbilical abnormalities. Identification of cis-regulatory elements of PITX2 is important to better understand the mechanisms of disease. Methods. Conserved noncoding elements surrounding PITX2/pitx2 were identified and examined through transgenic analysis in zebrafish; expression pattern was studied by in situ hybridization. Patient samples were screened for deletion/duplication of the PITX2 upstream region using arrays and probes. Results. Zebrafish pitx2 demonstrates conserved expression during ocular and craniofacial development. Thirteen conserved noncoding sequences positioned within a gene desert as far as 1.1 Mb upstream of the human PITX2 gene were identified; 11 have enhancer activities consistent with pitx2 expression. Ten elements mediated expression in the developing brain, four regions were active during eye formation, and two sequences were associated with craniofacial expression. One region, CE4, located approximately 111 kb upstream of PITX2, directed a complex pattern including expression in the developing eye and craniofacial region, the classic sites affected in ARS. Screening of ARS patients identified an approximately 7600-kb deletion that began 106 to 108 kb upstream of the PITX2 gene, leaving PITX2 intact while removing regulatory elements CE4 to CE13. Conclusions. These data suggest the presence of a complex distant regulatory matrix within the gene desert located upstream of PITX2 with an essential role in its activity and provides a possible mechanism for the previous reports of ARS in patients with balanced translocations involving the 4q25 region upstream of PITX2 and the current patient with an upstream deletion. PMID:20881290
Georgiou, Maria; Borghi, Giacomo; Spirou, Spiridon V; Loudos, George; Schaart, Dennis R
2014-05-21
The digital photon counter (DPC) is a recently developed type of digital silicon photomultiplier that combines low dark count rates, low readout noise, and fully digital, integrated readout circuitry with neighbor logic capability, system scalability, and MR compatibility. These are desirable properties for application in scintillation detectors for single photon emission computed tomography (SPECT). In this work, the feasibility of using a DPC array in combination with a CsI(Tl) crystal matrix as a potential detector for SPECT is investigated for the first time. Given the relatively long decay time of CsI(Tl), an important consideration is the influence on the detector performance of the DPC dark count rate as a function of temperature. We present a preliminary characterization of a detector assembled with an array of 2 × 2 × 3 mm(3) CsI(Tl) crystals. Preparatory measurements were acquired with a (57)Co source in order to optimize the light-guide thickness and the sensor settings. The spatial resolution of the detector was tested by acquiring flood maps with (57)Co as well as (99m)Tc sources. Three crystal identification algorithms were compared for the reconstruction of the flood maps. All crystal elements could be visualized clearly and high values of peak-to-valley ratios were achieved. Energy resolutions of ∼18.5% FWHM and ∼15% FWHM were measured at 122 keV and 140 keV, respectively. Temperature-dependent measurements indicate that the detector can work satisfactorily up to about 15 °C.
Anzaldo-Meneses, A.; Pereyra, P. . E-mail: ppereyra@correo.azc.uam.mx
2007-09-15
Based on the Sylvester and Frobenius theorems, we drastically enhance the feasibility of the transfer-matrix approach to deal with problems involving a large number of propagating and interfering modes, which require the solution of coupled differential equations and the evaluation of functions of matrix variables. We report closed formulas for the spectral decomposition of this type of functions. As specific example, besides the calculation of simple and well-known 1D one channel transfer matrices, we derive the multi-channel transfer matrix for an electron gas in the presence of a transverse electric field.
Kennedy, Deborah A.; Cooley, Kieran; Einarson, Thomas R.; Seely, Dugald
2012-01-01
Ionic footbaths are often used in holistic health centres and spas to aid in detoxification; however, claims that these machines eliminate toxins from the body have not been rigorously evaluated. In this proof-of-principle study, we sought to measure the release of potentially toxic elements from ionic footbaths into distilled and tap water with and without feet. Water samples were collected and analyzed following 30-minute ionic footbath sessions without feet using both distilled (n = 1) and tap water (n = 6) and following four ionic footbaths using tap water (once/week for 4 weeks) in six healthy participants. Urine collection samples were analyzed at four points during the study. Hair samples were analyzed for element concentrations at baseline and study conclusion. Contrary to claims made for the machine, there does not appear to be any specific induction of toxic element release through the feet when running the machine according to specifications. PMID:22174728
Iordanova, S.; Pashov, A.
2015-04-08
The study is on optical emission spectroscopy diagnostics of a single element of a matrix source of negative hydrogen ions. The method developed for description of the hydrogen atoms behaviour is based on analysis of the Balmer H{sub α} line profile, and it can be readily applied to various low pressure hydrogen discharges. The present observations reveal the existence of thermal as well as of non-thermal fast hydrogen atoms in the discharge. For processing of the experimental data a line shape model, which accounts for details of the plasma kinetics and the fine structure of the Balmer lines is developed. The fit of this model to the recorded at different experimental conditions line shapes results in the temperature of the thermal atoms, the mean energy of the fast atoms, the ratio between the densities of these two group of atoms and the relative populations of the fine structure components of the n = 3 hydrogen state. The present study indicates that the reactions leading to production of fast atoms and the process of energy exchange between thermal and fast atoms may be important for the correct modeling of the plasma kinetics.
Khachatryan, V; Sirunyan, A M; Tumasyan, A; Adam, W; Bergauer, T; Dragicevic, M; Erö, J; Friedl, M; Frühwirth, R; Ghete, V M; Hartl, C; Hörmann, N; Hrubec, J; Jeitler, M; Kiesenhofer, W; Knünz, V; Krammer, M; Krätschmer, I; Liko, D; Mikulec, I; Rabady, D; Rahbaran, B; Rohringer, H; Schöfbeck, R; Strauss, J; Treberer-Treberspurg, W; Waltenberger, W; Wulz, C-E; Mossolov, V; Shumeiko, N; Suarez Gonzalez, J; Alderweireldt, S; Bansal, S; Cornelis, T; De Wolf, E A; Janssen, X; Knutsson, A; Lauwers, J; Luyckx, S; Ochesanu, S; Rougny, R; Van De Klundert, M; Van Haevermaet, H; Van Mechelen, P; Van Remortel, N; Van Spilbeeck, A; Blekman, F; Blyweert, S; D'Hondt, J; Daci, N; Heracleous, N; Keaveney, J; Lowette, S; Maes, M; Olbrechts, A; Python, Q; Strom, D; Tavernier, S; Van Doninck, W; Van Mulders, P; Van Onsem, G P; Villella, I; Caillol, C; Clerbaux, B; De Lentdecker, G; Dobur, D; Favart, L; Gay, A P R; Grebenyuk, A; Léonard, A; Mohammadi, A; Perniè, L; Randle-Conde, A; Reis, T; Seva, T; Thomas, L; Vander Velde, C; Vanlaer, P; Wang, J; Zenoni, F; Adler, V; Beernaert, K; Benucci, L; Cimmino, A; Costantini, S; Crucy, S; Fagot, A; Garcia, G; Mccartin, J; Ocampo Rios, A A; Poyraz, D; Ryckbosch, D; Salva Diblen, S; Sigamani, M; Strobbe, N; Thyssen, F; Tytgat, M; Yazgan, E; Zaganidis, N; Basegmez, S; Beluffi, C; Bruno, G; Castello, R; Caudron, A; Ceard, L; Da Silveira, G G; Delaere, C; du Pree, T; Favart, D; Forthomme, L; Giammanco, A; Hollar, J; Jafari, A; Jez, P; Komm, M; Lemaitre, V; Nuttens, C; Pagano, D; Perrini, L; Pin, A; Piotrzkowski, K; Popov, A; Quertenmont, L; Selvaggi, M; Vidal Marono, M; Vizan Garcia, J M; Beliy, N; Caebergs, T; Daubie, E; Hammad, G H; Júnior, W L Aldá; Alves, G A; Brito, L; Correa Martins Junior, M; Martins, T Dos Reis; Molina, J; Mora Herrera, C; Pol, M E; Rebello Teles, P; Carvalho, W; Chinellato, J; Custódio, A; Da Costa, E M; De Jesus Damiao, D; De Oliveira Martins, C; Fonseca De Souza, S; Malbouisson, H; Matos Figueiredo, D; Mundim, L; Nogima, H; Prado Da Silva, W L; Santaolalla, J; Santoro, A; Sznajder, A; Tonelli Manganote, E J; Vilela Pereira, A; Bernardes, C A; Dogra, S; Fernandez Perez Tomei, T R; Gregores, E M; Mercadante, P G; Novaes, S F; Padula, Sandra S; Aleksandrov, A; Genchev, V; Hadjiiska, R; Iaydjiev, P; Marinov, A; Piperov, S; Rodozov, M; Stoykova, S; Sultanov, G; Vutova, M; Dimitrov, A; Glushkov, I; Litov, L; Pavlov, B; Petkov, P; Bian, J G; Chen, G M; Chen, H S; Chen, M; Cheng, T; Du, R; Jiang, C H; Plestina, R; Romeo, F; Tao, J; Wang, Z; Asawatangtrakuldee, C; Ban, Y; Liu, S; Mao, Y; Qian, S J; Wang, D; Xu, Z; Zhang, F; Zhang, L; Zou, W; Avila, C; Cabrera, A; Chaparro Sierra, L F; Florez, C; Gomez, J P; Gomez Moreno, B; Sanabria, J C; Godinovic, N; Lelas, D; Polic, D; Puljak, I; Antunovic, Z; Kovac, M; Brigljevic, V; Kadija, K; Luetic, J; Mekterovic, D; Sudic, L; Attikis, A; Mavromanolakis, G; Mousa, J; Nicolaou, C; Ptochos, F; Razis, P A; Rykaczewski, H; Bodlak, M; Finger, M; Finger, M; Assran, Y; Ellithi Kamel, A; Mahmoud, M A; Radi, A; Kadastik, M; Murumaa, M; Raidal, M; Tiko, A; Eerola, P; Voutilainen, M; Härkönen, J; Karimäki, V; Kinnunen, R; Lampén, T; Lassila-Perini, K; Lehti, S; Lindén, T; Luukka, P; Mäenpää, T; Peltola, T; Tuominen, E; Tuominiemi, J; Tuovinen, E; Wendland, L; Talvitie, J; Tuuva, T; Besancon, M; Couderc, F; Dejardin, M; Denegri, D; Fabbro, B; Faure, J L; Favaro, C; Ferri, F; Ganjour, S; Givernaud, A; Gras, P; Hamel de Monchenault, G; Jarry, P; Locci, E; Malcles, J; Rander, J; Rosowsky, A; Titov, M; Baffioni, S; Beaudette, F; Busson, P; Chapon, E; Charlot, C; Dahms, T; Dobrzynski, L; Filipovic, N; Florent, A; Granier de Cassagnac, R; Mastrolorenzo, L; Miné, P; Naranjo, I N; Nguyen, M; Ochando, C; Ortona, G; Paganini, P; Regnard, S; Salerno, R; Sauvan, J B; Sirois, Y; Veelken, C; Yilmaz, Y; Zabi, A; Agram, J-L; Andrea, J; Aubin, A; Bloch, D; Brom, J-M; Chabert, E C; Chanon, N; Collard, C; Conte, E; Fontaine, J-C; Gelé, D; Goerlach, U; Goetzmann, C; Le Bihan, A-C; Skovpen, K; Van Hove, P; Gadrat, S; Beauceron, S; Beaupere, N; Bernet, C; Boudoul, G; Bouvier, E; Brochet, S; Carrillo Montoya, C A; Chasserat, J; Chierici, R; Contardo, D; Courbon, B; Depasse, P; El Mamouni, H; Fan, J; Fay, J; Gascon, S; Gouzevitch, M; Ille, B; Kurca, T; Lethuillier, M; Mirabito, L; Pequegnot, A L; Perries, S; Ruiz Alvarez, J D; Sabes, D; Sgandurra, L; Sordini, V; Vander Donckt, M; Verdier, P; Viret, S; Xiao, H; Tsamalaidze, Z; Autermann, C; Beranek, S; Bontenackels, M; Edelhoff, M; Feld, L; Heister, A; Klein, K; Lipinski, M; Ostapchuk, A; Preuten, M; Raupach, F; Sammet, J; Schael, S; Schulte, J F; Weber, H; Wittmer, B; Zhukov, V; Ata, M; Brodski, M; Dietz-Laursonn, E; Duchardt, D; Erdmann, M; Fischer, R; Güth, A; Hebbeker, T; Heidemann, C; Hoepfner, K; Klingebiel, D; Knutzen, S; Kreuzer, P; Merschmeyer, M; Meyer, A; Mittag, G; Millet, P; Olschewski, M; Padeken, K; Papacz, P; Reithler, H; Schmitz, S A; Sonnenschein, L; Teyssier, D; Thüer, S; Cherepanov, V; Erdogan, Y; Flügge, G; Geenen, H; Geisler, M; 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Taylor, D; Vuosalo, C; Woods, N; Collaboration, Authorinst The Cms
A search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks is presented. Events with hadronic jets and one or two oppositely charged leptons are selected from a data sample corresponding to an integrated luminosity of 19.5[Formula: see text] collected by the CMS experiment at the LHC in [Formula: see text] collisions at a centre-of-mass energy of 8[Formula: see text]. In order to separate the signal from the larger [Formula: see text] + jets background, this analysis uses a matrix element method that assigns a probability density value to each reconstructed event under signal or background hypotheses. The ratio between the two values is used in a maximum likelihood fit to extract the signal yield. The results are presented in terms of the measured signal strength modifier, [Formula: see text], relative to the standard model prediction for a Higgs boson mass of 125[Formula: see text]. The observed (expected) exclusion limit at a 95 % confidence level is [Formula: see text] (3.3), corresponding to a best fit value [Formula: see text].
Khachatryan, Vardan
2015-06-09
A search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks is presented. Events with hadronic jets and one or two oppositely charged leptons are selected from a data sample corresponding to an integrated luminosity of 19.5fb^{-1} collected by the CMS experiment at the LHC in pp collisions at a centre-of-mass energy of 8TeV. In order to separate the signal from the larger tt¯ + jets background, this analysis uses a matrix element method that assigns a probability density value to each reconstructed event under signal or background hypotheses. The ratio between the two values is used in a maximum likelihood fit to extract the signal yield. The results are presented in terms of the measured signal strength modifier, μ, relative to the standard model prediction for a Higgs boson mass of 125GeV. The observed (expected) exclusion limit at a 95 % confidence level is μ < 4.2 (3.3), corresponding to a best fit value μ^ = 1.2^{+1.6}_{-1.5}.
NASA Astrophysics Data System (ADS)
Mättig, P.; Spiesberger, H.; Zeuner, W.
1993-12-01
The uncertainties in interpreting photon bremsstrahlung in the processe^ + e^ - to Z^0 to qbar q with matrix element calculations of O(ααs) are discussed. We address the stability of the calculations with respect to the emission of collinear photons and to higher-order QCD corrections and discuss the bias due to experimental photon isolation cuts. We analyze the resulting uncertainties for various procedures to define an event with a final state photon. Of particular interest are (i) a two-step procedure where first jets are reconstructed from hadrons alone and in a second step the photon is required to be isolated from these jets, and (ii) a ‘democratic’ procedure where the photon is inculded in the jet reconstruction but a certain maximum hadronic energy is allowed in the photon jet. In both cases we estimate that the uncertainties of the theoretical predictions, hadronization effects and the experimental photon isolation are of the order of 4%. To obtain this level of accuracy, however, the democratic procedure requires very hard cuts that reduce the event samples significantly.
NASA Astrophysics Data System (ADS)
Cave, Robert J.; Newton, Marshall D.
1997-06-01
Two independent methods are presented for the nonperturbative calculation of the electronic coupling matrix element (Hab) for electron transfer reactions using ab initio electronic structure theory. The first is based on the generalized Mulliken-Hush (GMH) model, a multistate generalization of the Mulliken Hush formalism for the electronic coupling. The second is based on the block diagonalization (BD) approach of Cederbaum, Domcke, and co-workers. Detailed quantitative comparisons of the two methods are carried out based on results for (a) several states of the system Zn2OH2+ and (b) the low-lying states of the benzene-Cl atom complex and its contact ion pair. Generally good agreement between the two methods is obtained over a range of geometries. Either method can be applied at an arbitrary nuclear geometry and, as a result, may be used to test the validity of the Condon approximation. Examples of nonmonotonic behavior of the electronic coupling as a function of nuclear coordinates are observed for Zn2OH2+. Both methods also yield a natural definition of the effective distance (rDA) between donor (D) and acceptor (A) sites, in contrast to earlier approaches which required independent estimates of rDA, generally based on molecular structure data.
NASA Astrophysics Data System (ADS)
Surowka, A. D.; Wrobel, P.; Marzec, M. M.; Adamek, D.; Szczerbowska-Boruchowska, M.
2016-09-01
The inherent structural heterogeneity of biological specimens poses a number of problems for analytical techniques to assess for the elemental composition of a sample, and this is the case with quantitative X-ray fluorescence (XRF). Differences in density along with any possible variation in thickness upon frequently used freeze drying of thin samples could influence the results of the quantification and therefore underlie one of the most critical matrix effects in XRF, often referred to as the mass thickness effect. In our study, we analyzed substantia nigra tissue samples of various thicknesses mounted onto silicon nitride membranes. The aim was to show up the variation in the mass thickness of the different substantia nigra tissue compartments: the neuromelanine pigmented neurons and neuropil could influence the final quantitative results. In that respect, the main goal was to derive several semi- and fully-quantitative methods to correct for the mass thickness effects using either a membrane Si transmission signal or the intensity of incoherently scattered primary X-ray radiation. Also, the pioneer topographic studies on dried substantia nigra tissue specimens demonstrated the drying procedure is accompanied by an around 80% reduction in the samples' thickness. The correction scheme is presented together with the semi-theoretical procedure developed to compute for the mass thickness for substantia nigra tissue structures, and the correction scheme's robustness is also presented.
Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; /Purdue U. /Waseda U.
2009-08-01
We present a search for associated production of the standard model (SM) Higgs boson and a Z boson where the Z boson decays to two leptons and the Higgs decays to a pair of b quarks in p{bar p} collisions at the Fermilab Tevatron. We use event probabilities based on SM matrix elements to construct a likelihood function of the Higgs content of the data sample. In a CDF data sample corresponding to an integrated luminosity of 2.7 fb{sup -1} we see no evidence of a Higgs boson with a mass between 100 GeV/c{sup 2} and 150 GeV/c{sup 2}. We set 95% confidence level (C.L.) upper limits on the cross-section for ZH production as a function of the Higgs boson mass m{sub H}; the limit is 8.2 times the SM prediction at m{sub H} = 115 GeV/c{sup 2}.
NASA Astrophysics Data System (ADS)
Aaltonen, T.; Adelman, J.; Akimoto, T.; González, B. Álvarez; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; Arisawa, T.; Artikov, A.; Ashmanskas, W.; Attal, A.; Aurisano, A.; Azfar, F.; Azzurri, P.; Badgett, W.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Bartsch, V.; Bauer, G.; Beauchemin, P.-H.; Bedeschi, F.; Beecher, D.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Beringer, J.; Bhatti, A.; Binkley, M.; Bisello, D.; Bizjak, I.; Blair, R. E.; Blocker, C.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Boisvert, V.; Bolla, G.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brau, B.; Bridgeman, A.; Brigliadori, L.; Bromberg, C.; Brubaker, E.; Budagov, J.; Budd, H. S.; Budd, S.; Burke, S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Byrum, K. L.; Cabrera, S.; Calancha, C.; Campanelli, M.; Campbell, M.; Canelli, F.; Canepa, A.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chang, S. H.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chou, J. P.; Choudalakis, G.; Chuang, S. H.; Chung, K.; Chung, W. H.; Chung, Y. S.; Chwalek, T.; Ciobanu, C. I.; Ciocci, M. A.; Clark, A.; Clark, D.; Compostella, G.; Convery, M. E.; Conway, J.; Cordelli, M.; Cortiana, G.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuenca Almenar, C.; Cuevas, J.; Culbertson, R.; Cully, J. C.; Dagenhart, D.; Datta, M.; Davies, T.; de Barbaro, P.; de Cecco, S.; Deisher, A.; de Lorenzo, G.; Dell'Orso, M.; Deluca, C.; Demortier, L.; Deng, J.; Deninno, M.; Derwent, P. F.; di Giovanni, G. P.; Dionisi, C.; di Ruzza, B.; Dittmann, J. 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Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harper, S.; Harr, R. F.; Harris, R. M.; Hartz, M.; Hatakeyama, K.; Hays, C.; Heck, M.; Heijboer, A.; Heinrich, J.; Henderson, C.; Herndon, M.; Heuser, J.; Hewamanage, S.; Hidas, D.; Hill, C. S.; Hirschbuehl, D.; Hocker, A.; Hou, S.; Houlden, M.; Hsu, S.-C.; Huffman, B. T.; Hughes, R. E.; Husemann, U.; Hussein, M.; Husemann, U.; Huston, J.; Incandela, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jayatilaka, B.; Jeon, E. J.; Jha, M. K.; Jindariani, S.; Johnson, W.; Jones, M.; Joo, K. K.; Jun, S. Y.; Jung, J. E.; Junk, T. R.; Kamon, T.; Kar, D.; Karchin, P. E.; Kato, Y.; Kephart, R.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, H. W.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kimura, N.; Kirsch, L.; Klimenko, S.; Knuteson, B.; Ko, B. R.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Korytov, A.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Krumnack, N.; Kruse, M.; Krutelyov, V.; Kubo, T.; Kuhr, T.; Kulkarni, N. P.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; Lazzizzera, I.; Lecompte, T.; Lee, E.; Lee, H. S.; Lee, S. W.; Leone, S.; Lewis, J. D.; Lin, C.-S.; Linacre, J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, T.; Lockyer, N. S.; Loginov, A.; Loreti, M.; Lovas, L.; Lucchesi, D.; Luci, C.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lyons, L.; Lys, J.; Lysak, R.; MacQueen, D.; Madrak, R.; Maeshima, K.; Makhoul, K.; Maki, T.; Maksimovic, P.; Malde, S.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Marino, C. P.; Martin, A.; Martin, V.; Martínez, M.; Martínez-Ballarín, R.; Maruyama, T.; Mastrandrea, P.; Masubuchi, T.; Mathis, M.; Mattson, M. E.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Menzione, A.; Merkel, P.; Mesropian, C.; Miao, T.; Miladinovic, N.; Miller, R.; Mills, C.; Milnik, M.; Mitra, A.; Mitselmakher, G.; Miyake, H.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlok, J.; Movilla Fernandez, P.; Mülmenstädt, J.; Mukherjee, A.; Muller, Th.; Mumford, R.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Nagano, A.; Naganoma, J.; Nakamura, K.; Nakano, I.; Napier, A.; Necula, V.; Nett, J.; Neu, C.; Neubauer, M. S.; Neubauer, S.; Nielsen, J.; Nodulman, L.; Norman, M.; Norniella, O.; Nurse, E.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Pagan Griso, S.; Palencia, E.; Papadimitriou, V.; Papaikonomou, A.; Paramonov, A. A.; Parks, B.; Pashapour, S.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Peiffer, T.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pinera, L.; Pitts, K.; Plager, C.; Pondrom, L.; Poukhov, O.; Pounder, N.; Prakoshyn, F.; Pronko, A.; Proudfoot, J.; Ptohos, F.; Pueschel, E.; Punzi, G.; Pursley, J.; Rademacker, J.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Renz, M.; Rescigno, M.; Richter, S.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Rossi, M.; Rossin, R.; Roy, P.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.; Sakumoto, W. K.; Saltó, O.; Santi, L.; Sarkar, S.; Sartori, L.; Sato, K.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, A.; Schmidt, E. E.; Schmidt, M. A.; Schmidt, M. P.; Schmitt, M.; Schwarz, T.; Scodellaro, L.; Scribano, A.; Scuri, F.; Sedov, A.; Seidel, S.; Seiya, Y.; Semenov, A.; Sexton-Kennedy, L.; Sforza, F.; Sfyrla, A.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shiraishi, S.; Shochet, M.; Shon, Y.; Shreyber, I.; Sidoti, A.; Sinervo, P.; Sisakyan, A.; Slaughter, A. J.; Slaunwhite, J.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Snihur, R.; Soha, A.; Somalwar, S.; Sorin, V.; Spalding, J.; Spreitzer, T.; Squillacioti, P.; Stanitzki, M.; St. Denis, R.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Strycker, G. L.; Stuart, D.; Suh, J. S.; Sukhanov, A.; Suslov, I.; Suzuki, T.; Taffard, A.; Takashima, R.; Takeuchi, Y.; Tanaka, R.; Tecchio, M.; Teng, P. K.; Terashi, K.; Thom, J.; Thompson, A. S.; Thompson, G. A.; Thomson, E.; Tipton, P.; Ttito-Guzmán, P.; Tkaczyk, S.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Tourneur, S.; Trovato, M.; Tsai, S.-Y.; Tu, Y.; Turini, N.; Ukegawa, F.; Vallecorsa, S.; van Remortel, N.; Varganov, A.; Vataga, E.; Vázquez, F.; Velev, G.; Vellidis, C.; Vidal, M.; Vidal, R.; Vila, I.; Vilar, R.; Vine, T.; Vogel, M.; Volobouev, I.; Volpi, G.; Wagner, P.; Wagner, R. G.; Wagner, R. L.; Wagner, W.; Wagner-Kuhr, J.; Wakisaka, T.; Wallny, R.; Wang, S. M.; Warburton, A.; Waters, D.; Weinberger, M.; Weinelt, J.; Wester, W. C., III; Whitehouse, B.; Whiteson, D.; Wicklund, A. B.; Wicklund, E.; Wilbur, S.; Williams, G.; Williams, H. H.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, C.; Wright, T.; Wu, X.; Würthwein, F.; Xie, S.; Yagil, A.; Yamamoto, K.; Yamaoka, J.; Yang, U. K.; Yang, Y. C.; Yao, W. M.; Yeh, G. P.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Yu, S. S.; Yun, J. C.; Zanello, L.; Zanetti, A.; Zhang, X.; Zheng, Y.; Zucchelli, S.; CDF Collaboration
2009-04-01
We present a measurement of the top quark mass in the all hadronic channel (t tmacr →b bmacr q1 qmacr 2q3 qmacr 4) using 943pb-1 of p pmacr collisions at s=1.96TeV collected at the CDF II detector at Fermilab (CDF). We apply the standard model production and decay matrix element (ME) to t tmacr candidate events. We calculate per-event probability densities according to the ME calculation and construct template models of signal and background. The scale of the jet energy is calibrated using additional templates formed with the invariant mass of pairs of jets. These templates form an overall likelihood function that depends on the top quark mass and on the jet energy scale (JES). We estimate both by maximizing this function. Given 72 observed events, we measure a top quark mass of 171.1±3.7(stat+JES)±2.1(syst)GeV/c2. The combined uncertainty on the top quark mass is 4.3GeV/c2.
Khachatryan, Vardan
2015-06-09
A search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks is presented. Events with hadronic jets and one or two oppositely charged leptons are selected from a data sample corresponding to an integrated luminosity of 19.5fb-1 collected by the CMS experiment at the LHC in pp collisions at a centre-of-mass energy of 8TeV. In order to separate the signal from the larger tt¯ + jets background, this analysis uses a matrix element method that assigns a probability density value to each reconstructed event under signal or background hypotheses. The ratiomore » between the two values is used in a maximum likelihood fit to extract the signal yield. The results are presented in terms of the measured signal strength modifier, μ, relative to the standard model prediction for a Higgs boson mass of 125GeV. The observed (expected) exclusion limit at a 95 % confidence level is μ < 4.2 (3.3), corresponding to a best fit value μ^ = 1.2+1.6-1.5.« less
NASA Technical Reports Server (NTRS)
Grillenbeck, Anton M.; Dillinger, Stephan A.; Elliott, Kenny B.
1998-01-01
Theoretical and experimental studies have been performed to investigate the potential and limitations of the modal characterization of a typical spacecraft bus structure by means of active structure elements. The aim of these studies has been test and advance tools for performing an accurate on-orbit modal identification which may be characterized by the availability of a generally very limited test instrumentation, autonomous excitation capabilities by active structure elements and a zero-g environment. The NASA LARC CSI Evolutionary Testbed provided an excellent object for the experimental part of this study program. The main subjects of investigation were: (1) the selection of optimum excitation and measurement to unambiguously identify modes of interest; (2) the applicability of different types of excitation means with focus on active structure elements; and (3) the assessment of the modal identification potential of different types of excitation functions and modal analysis tools. Conventional as well as dedicated modal analysis tools were applied to determine modal parameters and mode shapes. The results will be presented and discussed based on orthogonality checks as well as on suitable indicators for the quality of the acquired modes with respect to modal purity. In particular, the suitability for modal analysis of the acquired frequency response functions as obtained by excitation with active structure elements will be demonstrated with the help of reciprocity checks. Finally, the results will be summarized in a procedure to perform an on-orbit modal identification, including an indication of limitation to be observed.
Marguí, E; Iglesias, M; Camps, F; Sala, L; Hidalgo, M
2016-03-01
The presence of potentially toxic elements (PTEs) may hinder a more widespread application of biosolids in agriculture. At present, the European Directive 86/278/CEE limit the total concentrations of seven metals (Cu, Cr, Ni, Pb, Zn, Cd and Hg) in agricultural soils and in sewage sludges used as fertilizers but it has not taken into consideration the potential impacts of other emerging micropollutants that may be present in the biosolids as well as their mobility. The aim of this study was to evaluate the accumulation and mobility of 13 elements (including regulated metals and other inorganic species) in agricultural soils repeatedly amended with biosolids for 15 years. Firstly, three digestions programs using different acid mixtures were tested to evaluate the most accurate and efficient method for analysis of soil and sludge. Results demonstrated that sewage sludge application increased concentrations of Pb and Hg in soil, but values did not exceed the quality standard established by legislation. In addition, other elements (As, Co, Sb, Ag, Se and Mn) that at present are not regulated by the Spanish and European directives were identified in the sewage sludge, and significant differences were found between Ag content in soils amended with biosolids in comparison with control soils. This fact can be related to the increasing use of silver nanoparticles in consumer products due to their antibacterial properties. Results from the leaching tests show up that, in general, the mobility degree for both regulated and non-regulated elements in soils amended with biosolids was quite low (<10 %).
McGuire, Jacob D.; Walker, Mary P.; Dusevich, Vladimir; Wang, Yong; Gorski, Jeff P.
2015-01-01
Although mature enamel is predominantly composed of mineral, a previously uncharacterized organic matrix layer remains in the post-eruptive tissue that begins at the dentin enamel junction and extends 200–300 µm towards the outer tooth surface. Identification of the composition of this layer has been hampered by its insolubility; however, we have developed a single step method to isolate the organic enamel matrix relatively intact. After dissociative dissolution of the matrix with SDS and urea, initial characterization by Western blotting and gel zymography indicates the presence of type IV and type VII basement membrane collagens and active matrix metalloproteinase-20. When combined with data from transgenic knockout mice and from human mutations, these data suggest that the enamel organic matrix (EOM) and dentin enamel junction may have a structural and functional relationship with basement membranes, e.g. skin. To clarify this relationship, we hypothesize a “foundation” model which proposes that components of the EOM form a support structure that stabilizes the crystalline enamel layer, and bonds it to the underlying dentin along the dentin enamel junction. Since we have also co-localized an active matrix metalloproteinase to this layer, our hypothesis suggests that, under pathologic conditions, MMP-mediated degradation of the EOM could destabilize the enamel–dentin interface. PMID:25158177
The Kuril Islands as a potential region for aquaculture: Trace elements in chum salmon.
Khristoforova, Nadezhda K; Tsygankov, Vasiliy Yu; Lukyanova, Olga N; Boyarova, Margarita D
2016-06-01
The Kuril Islands region is considered promising for development of salmon aquaculture. There are 41 salmon fish hatcheries in the Sakhalin Island and the Kuril Islands, 34 of them are hatcheries of the chum. Therefore, concentrations of six elements (Zn, Cu, Cd, Pb, As, and Hg) were determined in chum salmon were caught in this region. The contents of toxic elements (Cd, Pb, As, and Hg) don't exceed their maximum permissible concentrations (MPC) according to the Russian sanitary standards, but concentration of Pb are closely to MPC. Increased concentrations of Pb in wild chum have the natural origin. The unusual conditions of the Western Pacific are formed under the influence such factors as volcanism and upwelling.
NASA Astrophysics Data System (ADS)
Stenroos, Matti
2016-11-01
Boundary element methods (BEM) are used for forward computation of bioelectromagnetic fields in multi-compartment volume conductor models. Most BEM approaches assume that each compartment is in contact with at most one external compartment. In this work, I present a general surface integral equation and BEM discretization that remove this limitation and allow BEM modeling of general piecewise-homogeneous medium. The new integral equation allows positioning of field points at junctioned boundary of more than two compartments, enabling the use of linear collocation BEM in such a complex geometry. A modular BEM implementation is presented for linear collocation and Galerkin approaches, starting from the standard formulation. The approach and resulting solver are verified in four ways, including comparisons of volume and surface potentials to those obtained using the finite element method (FEM), and the effect of a hole in skull on electroencephalographic scalp potentials is demonstrated.
Stenroos, Matti
2016-11-21
Boundary element methods (BEM) are used for forward computation of bioelectromagnetic fields in multi-compartment volume conductor models. Most BEM approaches assume that each compartment is in contact with at most one external compartment. In this work, I present a general surface integral equation and BEM discretization that remove this limitation and allow BEM modeling of general piecewise-homogeneous medium. The new integral equation allows positioning of field points at junctioned boundary of more than two compartments, enabling the use of linear collocation BEM in such a complex geometry. A modular BEM implementation is presented for linear collocation and Galerkin approaches, starting from the standard formulation. The approach and resulting solver are verified in four ways, including comparisons of volume and surface potentials to those obtained using the finite element method (FEM), and the effect of a hole in skull on electroencephalographic scalp potentials is demonstrated.
NASA Astrophysics Data System (ADS)
Gall, H. E.; Rao, P.; O'Connor, G.
2013-12-01
The land-application of biosolids and animal manure to agricultural fields has the potential to negatively impact the quality of nearby surface and subsurface water due to the presence of emerging contaminants in these residuals. We investigated the extent to which the vadose zone acts as a hydrologic and biogeochemical filter of two emerging contaminants, Triclosan (TCS) and estrone (E1) using a coupled source zone and vadose zone modeling approach. Monte Carlo simulations were run for a year following residual applications to explore the following research questions: (1) how does the application matrix (e.g., de-watered solids, liquid lagoon effluent, etc.) affect PPCP mass fluxes?; (2) how do hydro-climatic conditions and soil type affect PPCP mass fluxes?; (3) what role does the presence of macropore pathways play in PPCP export from the vadose zone; and (4) does the long-term, repeated application of residuals affect the ability of the vadose zone to act as an effective biogeochemical filter? The simulations were conducted for a sub-tropical climate with sand (e.g., Florida) and a humid climate with a silty clay loam (e.g., Midwestern United States). Simulation results suggest that the potential mobility of emerging contaminants increases linearly with increasing fraction applied to the mobile phase of the source zone (i.e., higher PPCP mass fraction in the dissolved phase during application). Following a single application, the total amount of PPCP mass exported from the source zone over the course of a year can be as high as 70% in a sub-tropical climate with sand soil. However, these types of soils do not have macropore flow pathways and the annual PPCP mass exported from the vadose zone is less than 1% of the mass applied. The higher organic carbon content in a silty clay loam reduces the amount of PPCP mass released from the source zone to less than 5% of the mass applied. In the presence of macropore pathways, the silty clay loam's vadose zone acts as a
Potential of Vinca rosea extracts in modulating trace element profile: a chemopreventive approach.
Mohanta, Bidhan; Sudarshan, Mathummal; Boruah, Mandira; Chakraborty, Anindita
2007-01-01
Diethylnitrosamine (DEN) was used as cancer-inducing agent in the experimental animals. Vinca rosea extract was supplemented with the drinking water as a chemopreventive agent. After 4 wk of treatment, animals were sacrificed and livers were excised. Nuclei and mitochondria were separated by differential centrifugation. The proton-induced X-ray emission technique has been used as the analytical method. Elemental analysis were performed for whole liver, nuclei, and mitochondria.V. rosea plant parts were also analyzed for elemental contents. Treatment with DEN caused an increase of Ni, Zn, and Cr levels in the whole liver and nuclei. There is an increase in Fe concentration in the liver, although the level decreased in mitochondria. The concentrations of Br and Ca were unchanged in the liver as a whole, but there were substantial increases of Br in nuclei and mitochondria, whereas Ca levels depleted drastically in these two organelles. Vinca extracts were effective in reverting the changes in the elemental concentration in the hepatic tissue as a whole, but were not that effective at subcellular levels.
Cachada, Anabela; Pereira, Maria Eduarda; Ferreira da Silva, Eduardo; Duarte, Armando Costa
2012-01-01
Urban and industrial development has caused a major impact on environmental soil quality. This work assesses the extent and severity of contamination in a small urban area subjected to an industrial impact and identifies the major anthropogenic inputs. Twenty-six soil samples were collected from agricultural and urban sites, and concentrations of potentially toxic elements (As, Cd, Cu, Cr, Fe, Mn, Ni, Pb and Zn), PAHs and PCBs, were determined. In spite of the low median concentrations observed, some sites represent a potential hazard for human health and ecosystems. Concentrations of contaminants were higher than those found in a nearby city, indicating that the study area is affected by the surrounding industry. The use of multivariate statistical analyses allowed for the identification of the main factors controlling the variability of potentially toxic elements and organic pollutants in the soils. The presence of Cr, Fe, Mn and Ni was associated with geogenic inputs, and Cu, Pb, Zn, As, PAHs and PCBs were associated with anthropogenic inputs. Industry and traffic were the most important anthropogenic sources. Soil characteristics were identified as important factors controlling the spatial variability of elements, both from recognised natural and anthropogenic origin. Differences between land uses were observed, which may be attributed to both management practices and proximity to sources.
NASA Technical Reports Server (NTRS)
Dvorak, F. A.; Woodward, F. A.
1974-01-01
An analysis method and computer program have been developed for the calculation of the viscosity dependent aerodynamic characteristics of multi-element infinite swept wings in incompressible flow. The wing configuration consisting at the most of a slat, a main element and double slotted flap is represented in the method by a large number of panels. The inviscid pressure distribution about a given configuration in the normal chord direction is determined using a two dimensional potential flow program employing a vortex lattice technique. The boundary layer development over each individual element of the high lift configuration is determined using either integral or finite difference boundary layer techniques. A source distribution is then determined as a function of the calculated boundary layer displacement thickness and pressure distributions. This source distribution is included in the second calculation of the potential flow about the configuration. Once the solution has converged (usually after 2-5 iterations between the potential flow and boundary layer calculations) lift, drag, and pitching moments can be determined as functions of Reynolds number.
Multipole Matrix of Green Function of Laplace Equation
NASA Astrophysics Data System (ADS)
Makuch, K.; Górka, P.
Multipole matrix elements of Green function of Laplace equation are calculated. The multipole matrix elements of Green function in electrostatics describe potential on a sphere which is produced by a charge distributed on the surface of a different (possibly overlapping) sphere of the same radius. The matrix elements are defined by double convolution of two spherical harmonics with the Green function of Laplace equation. The method we use relies on the fact that in the Fourier space the double convolution has simple form. Therefore we calculate the multipole matrix from its Fourier transform. An important part of our considerations is simplification of the three dimensional Fourier transformation of general multipole matrix by its rotational symmetry to the one-dimensional Hankel transformation.
Jursic, B.S.
1996-12-31
Up to four ionization potentials of elements from the second-row of the periodic table were computed using the ab initio (HF, MP2, MP3, MP4, QCISD, GI, G2, and G2MP2) and DFT (B3LY, B3P86, B3PW91, XALPHA, HFS, HFB, BLYP, BP86, BPW91, BVWN, XAPLY, XAP86, XAPW91, XAVWN, SLYR SP86, SPW91 and SVWN) methods. In all of the calculations, the large 6-311++G(3df,3pd) gaussian type of basis set was used. The computed values were compared with the experimental results and suitability of the ab initio and DFF methods were discussed, in regard to reproducing the experimental data. From the computed ionization potentials of the second-row elements, it can be concluded that the HF ab initio computation is not capable of reproducing the experimental results. The computed ionization potentials are too low. However, by using the ab initio methods that include electron correlation, the computed IPs are becoming much closer to the experimental values. In all cases, with the exception of the first ionization potential for oxygen, the G2 computation result produces ionization potentials that are indistinguishable from the experimental results.
NASA Astrophysics Data System (ADS)
Rabahallah, M.; Bouvier, S.; Balan, T.; Bacroix, B.; Teodosiu, C.
2007-04-01
In this work, an implicit, backward Euler time integration scheme is developed for an anisotropic, elastic-plastic model based on strain-rate potentials. The constitutive algorithm includes a sub-stepping procedure to deal with the strong nonlinearity of the plastic potentials when applied to FCC materials. The algorithm is implemented in the static implicit version of the Abaqus finite element code. Several recent plastic potentials have been implemented in this framework. The most accurate potentials require the identification of about twenty material parameters. Both mechanical tests and micromechanical simulations have been used for their identification, for a number of BCC and FCC materials. The impact of the identification procedure on the prediction of ears in cup drawing is investigated.
Rabahallah, M.; Bouvier, S.; Bacroix, B.; Teodosiu, C.; Balan, T.
2007-04-07
In this work, an implicit, backward Euler time integration scheme is developed for an anisotropic, elastic-plastic model based on strain-rate potentials. The constitutive algorithm includes a sub-stepping procedure to deal with the strong nonlinearity of the plastic potentials when applied to FCC materials. The algorithm is implemented in the static implicit version of the Abaqus finite element code. Several recent plastic potentials have been implemented in this framework. The most accurate potentials require the identification of about twenty material parameters. Both mechanical tests and micromechanical simulations have been used for their identification, for a number of BCC and FCC materials. The impact of the identification procedure on the prediction of ears in cup drawing is investigated.
Cleary, Paul W; Prakash, Mahesh
2004-09-15
Particle-based simulation methods, such as the discrete-element method and smoothed particle hydrodynamics, have specific advantages in modelling complex three-dimensional (3D) environmental fluid and particulate flows. The theory of both these methods and their relative advantages compared with traditional methods will be discussed. Examples of 3D flows on realistic topography illustrate the environmental application of these methods. These include the flooding of a river valley as a result of a dam collapse, coastal inundation by a tsunami, volcanic lava flow and landslides. Issues related to validation and quality data availability are also discussed.
Finite Element Simulation of Sheet Metal Forming Using Anisotropic Strain-Rate Potentials
Rabahallah, Meziane; Balan, Tudor; Bouvier, Salima; Bacroix, Brigitte; Teodosiu, Cristian
2007-05-17
In continuum mechanics, plastic anisotropy is described using anisotropic stress potentials or, alternatively, strain-rate potentials. In this work, a stress update algorithm is developed for this later case. The implicit, backward Euler method is adopted. A specific numerical treatment is required to deal with the plasticity criterion, which is not defined explicitly. Also, a sub-stepping procedure is adopted in order to deal with the strong nonlinearity of the yield surfaces when applied to FCC materials. The resulting algorithm is implemented in the static implicit version of the Abaqus FE code. Several recent plastic potentials have been implemented in this framework and their parameters identified for a number of BCC and FCC materials. Numerical simulations of a cup drawing process are performed in order to address the robustness of the implementation and the ability of these potentials to predict e.g. earing for materials with different anisotropy.
Eble, C.F.; Hower, J.C.
1997-01-01
Coal in the Eastern Kentucky coalfield has been, and continues to be, a valuable energy resource, especially for the electric utility industry. However, Federal mandates in Titles III and IV of the Clean Air Act Amendments of 1990 have placed increasingly stringent demands on the type and grade of coal that can be burnt in an environmentally acceptable manner. Therefore, a greater understanding of the spatial and temporal distribution of thickness and quality parameters, and the geologic factors that control their distribution, is critical if the Eastern Kentucky coalfield is to continue to be a major producer of high-quality coal. Information from the Kentucky Geological Survey's Coal Resource Information System database is used in this paper to document the geographic and stratigraphic distribution of important factors such as bed thickness, calorific value, ash yield and total sulfur content. The distribution of 15 elements that naturally occur in trace amounts in Kentucky coal is also discussed, as these elements may require monitoring with passage of Title III of the Clean Air Act Amendments of 1990. ?? 1997 Elsevier Science Ltd.
Several different upstream promoter elements can potentiate transactivation by the BPV-1 E2 protein.
Ham, J; Dostatni, N; Arnos, F; Yaniv, M
1991-01-01
The enhancer and upstream promoter regions of RNA polymerase II transcribed genes modulate the rate of transcription initiation and establish specific patterns of gene expression. Both types of region consist of clusters of DNA binding sites for nuclear proteins. To determine how efficiently the same factor can activate transcription when acting as an enhancer or promoter factor, we have studied transactivation by the BPV-1 E2 protein, a papillomavirus transcriptional regulator. By cotransfecting a BPV-1 E2 expression vector and a series of reporter plasmids containing well-defined chimeric promoters we have found that whilst E2 can strongly stimulate complex promoters such as that of the HSV tk gene, it does not efficiently activate constructions containing only a TATA box and initiation site. We show that insertion of upstream promoter elements, but not of spacer DNA, between E2 binding sites and the TATA box greatly increases E2 activation. This effect was observed with more than one type of upstream promoter element, is not related to the strength of the promoter and is unlikely to result from co-operative DNA binding by E2 and the transcription factors tested. These results would suggest that E2 has the properties of an enhancer rather than promoter factor and that in certain cases promoter and enhancer factors may affect different steps in the process of transcriptional activation. Images PMID:1655407
NASA Astrophysics Data System (ADS)
Glattauer, R.; Schwanda, C.; Abdesselam, A.; Adachi, I.; Adamczyk, K.; Aihara, H.; Al Said, S.; Asner, D. M.; Aushev, T.; Ayad, R.; Aziz, T.; Badhrees, I.; Bakich, A. M.; Bansal, V.; Barberio, E.; Bhuyan, B.; Biswal, J.; Bonvicini, G.; Bozek, A.; Bračko, M.; Breibeck, F.; Browder, T. E.; Červenkov, D.; Chekelian, V.; Chen, A.; Cheon, B. G.; Chilikin, K.; Chistov, R.; Cho, K.; Chobanova, V.; Choi, Y.; Cinabro, D.; Dalseno, J.; Danilov, M.; Dash, N.; Dingfelder, J.; Doležal, Z.; Drutskoy, A.; Dutta, D.; Eidelman, S.; Farhat, H.; Fast, J. E.; Ferber, T.; Frey, A.; Fulsom, B. G.; Gaur, V.; Gabyshev, N.; Garmash, A.; Gillard, R.; Goh, Y. M.; Goldenzweig, P.; Golob, B.; Greenwald, D.; Haba, J.; Hamer, P.; Hara, T.; Hasenbusch, J.; Hayasaka, K.; Hayashii, H.; Hou, W.-S.; Hsu, C.-L.; Iijima, T.; Inami, K.; Inguglia, G.; Ishikawa, A.; Jeon, H. B.; Joffe, D.; Joo, K. K.; Julius, T.; Kang, K. H.; Kato, E.; Kawasaki, T.; Kiesling, C.; Kim, D. Y.; Kim, J. B.; Kim, J. H.; Kim, K. T.; Kim, M. J.; Kim, S. H.; Kim, Y. J.; Kinoshita, K.; Kodyš, P.; Korpar, S.; Križan, P.; Krokovny, P.; Kuhr, T.; Kuzmin, A.; Kwon, Y.-J.; Lee, I. S.; Li, L.; Li, Y.; Libby, J.; Liu, Y.; Liventsev, D.; Lukin, P.; MacNaughton, J.; Masuda, M.; Matvienko, D.; Miyabayashi, K.; Miyata, H.; Mizuk, R.; Mohanty, G. B.; Mohanty, S.; Moll, A.; Moon, H. K.; Mussa, R.; Nakano, E.; Nakao, M.; Nanut, T.; Natkaniec, Z.; Nayak, M.; Nisar, N. K.; Nishida, S.; Ogawa, S.; Okuno, S.; Oswald, C.; Pakhlov, P.; Pakhlova, G.; Pal, B.; Park, H.; Pedlar, T. K.; Pesántez, L.; Pestotnik, R.; Petrič, M.; Piilonen, L. E.; Pulvermacher, C.; Rauch, J.; Ribežl, E.; Ritter, M.; Rostomyan, A.; Sahoo, H.; Sakai, Y.; Sandilya, S.; Santelj, L.; Sanuki, T.; Savinov, V.; Schneider, O.; Schnell, G.; Schwartz, A. J.; Seino, Y.; Senyo, K.; Seon, O.; Sevior, M. E.; Shebalin, V.; Shibata, T.-A.; Shiu, J.-G.; Shwartz, B.; Sibidanov, A.; Simon, F.; Sohn, Y.-S.; Sokolov, A.; Solovieva, E.; Starič, M.; Sumiyoshi, T.; Tamponi, U.; Teramoto, Y.; Trabelsi, K.; Trusov, V.; Uchida, M.; Unno, Y.; Uno, S.; Urquijo, P.; Usov, Y.; Van Hulse, C.; Vanhoefer, P.; Varner, G.; Varvell, K. E.; Vorobyev, V.; Vossen, A.; Wang, C. H.; Wang, M.-Z.; Wang, P.; Watanabe, Y.; Won, E.; Yamamoto, H.; Yamashita, Y.; Yook, Y.; Zhang, Z. P.; Zhilich, V.; Zhulanov, V.; Zupanc, A.; Belle Collaboration
2016-02-01
We present a determination of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |Vc b| using the decay B →D ℓνℓ (ℓ=e ,μ ) based on 711 fb-1 of e+e-→ϒ (4 S ) data recorded by the Belle detector and containing 772 ×106 B B ¯ pairs. One B meson in the event is fully reconstructed in a hadronic decay mode, while the other, on the signal side, is partially reconstructed from a charged lepton and either a D+ or D0 meson in a total of 23 hadronic decay modes. The isospin-averaged branching fraction of the decay B →D ℓνℓ is found to be B (B0→D-ℓ+νℓ )=(2.31 ±0.03 (stat )±0.11 (syst ))% . Analyzing the differential decay rate as a function of the hadronic recoil with the parametrization of Caprini, Lellouch, and Neubert and using the form-factor prediction G (1 ) =1.0541 ±0.0083 calculated by FNAL/MILC, we obtain ηEW|Vc b| =(40.12 ±1.34 )×10-3 , where ηEW is the electroweak correction factor. Alternatively, assuming the model-independent form-factor parametrization of Boyd, Grinstein, and Lebed and using lattice QCD data from the FNAL/MILC and HPQCD collaborations, we find ηEW|Vc b| =(41.10 ±1.14 )×10-3 .
NASA Astrophysics Data System (ADS)
Dey, B.; Meyer, C. A.; Bellis, M.; Williams, M.; Adhikari, K. P.; Adikaram, D.; Aghasyan, M.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Ball, J.; Baltzell, N. A.; Battaglieri, M.; Bedlinskiy, I.; Biselli, A. S.; Bono, J.; Boiarinov, S.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Cortes, O.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Doughty, D.; Dugger, M.; Dupre, R.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Fedotov, G.; Fegan, S.; Fleming, J. A.; Garçon, M.; Gevorgyan, N.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Glazier, D. I.; Goetz, J. T.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Hafidi, K.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hicks, K.; Ho, D.; Holtrop, M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Jenkins, D.; Jo, H. S.; Joo, K.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Koirala, S.; Kubarovsky, V.; Kuhn, S. E.; Kuleshov, S. V.; Lenisa, P.; Livingston, K.; Lu, H.; MacGregor, I. J. D.; Markov, N.; Mayer, M.; McCracken, M. E.; McKinnon, B.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Montgomery, R. A.; Moriya, K.; Moutarde, H.; Munevar, E.; Munoz Camacho, C.; Nadel-Turonski, P.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Pappalardo, L. L.; Paremuzyan, R.; Park, K.; Pasyuk, E.; Peng, P.; Phillips, J. J.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Protopopescu, D.; Puckett, A. J. R.; Rimal, D.; Ripani, M.; Ritchie, B. G.; Rizzo, A.; Rossi, P.; Roy, P.; Sabatié, F.; Saini, M. S.; Schott, D.; Schumacher, R. A.; Seder, E.; Senderovich, I.; Sharabian, Y. G.; Simonyan, A.; Smith, E. S.; Sober, D. I.; Sokhan, D.; Stepanyan, S. S.; Stoler, P.; Strakovsky, I. I.; Strauch, S.; Sytnik, V.; Taiuti, M.; Tang, W.; Tkachenko, S.; Ungaro, M.; Vernarsky, B.; Vlassov, A. V.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.; CLAS Collaboration
2014-05-01
High-statistics measurements of differential cross sections and spin density matrix elements for the reaction γp →ϕp have been made using the CLAS detector at Jefferson Lab. We cover center-of-mass energies (√s ) from 1.97 to 2.84 GeV, with an extensive coverage in the ϕ production angle. The high statistics of the data sample made it necessary to carefully account for the interplay between the ϕ natural lineshape and effects of the detector resolution, that are found to be comparable in magnitude. We study both the charged- (ϕ →K+K-) and neutral- (ϕ →KS0KL0) KK ¯ decay modes of the ϕ. Further, for the charged mode, we differentiate between the cases where the final K- track is directly detected or its momentum reconstructed as the total missing momentum in the event. The two charged-mode topologies and the neutral-mode have different resolutions and are calibrated against each other. Extensive usage is made of kinematic fitting to improve the reconstructed ϕ mass resolution. Our final results are reported in 10- and mostly 30-MeV-wide √s bins for the charged- and the neutral-modes, respectively. Possible effects from K+Λ* channels with pKK ¯ final states are discussed. These present results constitute the most precise and extensive ϕ photoproduction measurements to date and in conjunction with the ω photoproduction results recently published by CLAS, will greatly improve our understanding of low energy vector meson photoproduction.
Aubert, B.
2007-06-06
We present a combined measurement of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub cb}| and of the parameters {rho}{sup 2}, R{sub 1}(1), and R{sub 2}(1), which fully characterize the form factors for the B{sup 0} {yields} D*-{ell}+?{sub {ell}} decay in the framework of HQET. The results, based on a selected sample of about 52,800 B{sup 0} {yields} D*-{ell}+?{sub {ell}} decays, recorded by the BABAR detector, are {rho}{sup 2} = 1.156 {+-} 0.094 {+-} 0.028, R{sub 1}(1) = 1.329{+-}0.131{+-}0.044, R{sub 2}(1) = 0.859{+-}0.077{+-}0.022, and F(1)|V{sub cb}| = (35.0{+-}0.4{+-}1.1)x10-3. The first error is the statistical and the second is the systematic uncertainty. Combining these measurements with the previous BABAR measurement of the form factors, which employs a different ?t technique on a partial sample of the data, we improve the statistical precision of the result, {rho}{sup 2} = 1.179 {+-} 0.048 {+-} 0.028,R{sub 1}(1) = 1.417 {+-} 0.061 {+-} 0.044,R{sub 2}(1) = 0.836 {+-} 0.037 {+-} 0.022, and F(1)|V{sub cb}| = (34.7 {+-} 0.3 {+-} 1.1) x 10-3. Using lattice calculations for the axial form factor F(1), we extract |V{sub cb}| = (37.7{+-}0.3{+-}1.2{+-}{sup 1.2}{sub 1.4})x10{sup -3}, where the third error is due to the uncertainty in F(1). We also present a measurement of the exclusive branching fraction, B = (4.77 {+-} 0.04 {+-} 0.39)%.
Grewe, E.-W.; Frekers, D.; Rakers, S.; Baeumer, C.; Dohmann, H.; Thies, J.; Adachi, T.; Fujita, Y.; Shimbara, Y.; Botha, N. T.; Fujita, H.; Hatanaka, K.; Nakanishi, K.; Sakemi, Y.; Shimizu, Y.; Tameshige, Y.; Tamii, A.; Negret, A.; Popescu, L.; Neveling, R.
2007-11-15
High-resolution ({sup 3}He,t) measurements on the double {beta}-decay ({beta}{beta}) nucleus {sup 48}Ca have been performed at RCNP (Osaka, Japan) to determine Gamow-Teller (GT{sup -}) transitions to the nucleus {sup 48}Sc, which represents the intermediate nucleus in the second-order perturbative description of the {beta}{beta} decay. At a bombarding energy of E{sub {sup 3}He}=420 MeV an excitation energy resolution of 40 keV was achieved. The measurements were performed at two angle positions of the Grand Raiden Spectrometer (GRS): 0 deg. and 2.5 deg. The results of both settings were combined to achieve angular distributions, by which the character of single transitions could be determined. To characterize the different multipoles, theoretical angular distributions for states with J{sup {pi}}=1{sup +},2{sup +},2{sup -}, and 3{sup +} were calculated using the distorted-wave Born approximation (DWBA) Code DW81. The GT{sup -} strength was extracted up to E{sub x}=7 MeV and combined with corresponding GT{sup +} strength deduced from the {sup 48}Ti(d,{sup 2}He){sup 48}Sc data to calculate the low-energy part of the {beta}{beta}-decay matrix element for the {sup 48}Ca 2{nu}{beta}{beta} decay. We show that after applying trivial momentum corrections to the ({sup 3}He,t) spectrum, the two reaction probes (p,n) and ({sup 3}He,t) reveal a spectral response to an impressively high degree of similarity in the region of low momentum transfer.
Dey, B.; Meyer, C. A.; Bellis, M.; ...
2014-05-27
High-statistics measurements of differential cross sections and spin density matrix elements for the reaction γ p → Φp have been made using the CLAS detector at Jefferson Lab. We cover center-of-mass energies (√s) from 1.97 to 2.84 GeV, with an extensive coverage in the Φ production angle. The high statistics of the data sample made it necessary to carefully account for the interplay between the Φ natural lineshape and effects of the detector resolution, that are found to be comparable in magnitude. We study both the charged- (Φ → K⁺K⁻) and neutral- (Φ → K0SK0L)more » $$K\\bar{K}$$ decay modes of the Φ. Further, for the charged mode, we differentiate between the cases where the final K⁻ track is directly detected or its momentum reconstructed as the total missing momentum in the event. The two charged-mode topologies and the neutral-mode have different resolutions and are calibrated against each other. Extensive usage is made of kinematic fitting to improve the reconstructed Φ mass resolution. Our final results are reported in 10- and mostly 30-MeV-wide √s bins for the charged- and the neutral-mode, respectively. Possible effects from K⁺Λ* channels with p$$K\\bar{K}$$ final-states are discussed. These present results constitute the most precise and extensive Φ photoproduction measurements to date and in conjunction with the ω photoproduction results recently published by CLAS, will greatly improve our understanding of low energy vector meson photoproduction.« less
Determination of the Form Factors for the Decay B0 -> D*-l+nu_l and of the CKM Matrix Element |Vcb|
Aubert, B.
2006-09-26
The authors present a combined measurement of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub cb}| and of the parameters {rho}{sup 2}, R{sub 1}, and R{sub 2}, which fully characterize the form factors of the B{sup 0} {yields} D*{sup -}{ell}{sup +}{nu}{sub {ell}} decay in the framework of HQET, based on a sample of about 52,800 B{sup 0} {yields} D*{sup -}{ell}{sup +}{nu}{sub {ell}} decays recorded by the BABAR detector. The kinematical information of the fully reconstructed decay is used to extract the following values for the parameters (where the first errors are statistical and the second systematic): {rho}{sup 2} = 1.156 {+-} 0.094 {+-} 0.028, R{sub 1} = 1.329 {+-} 0.131 {+-} 0.044, R{sub 2} = 0.859 {+-} 0.077 {+-} 0.022, F(1)|V{sub cb}| = (35.03 {+-} 0.39 {+-} 1.15) x 10{sup -3}. By combining these measurements with the previous BABAR measurements of the form factors which employs a different technique on a partial sample of the data, they improve the statistical accuracy of the measurement, obtaining: {rho}{sup 2} = 1.179 {+-} 0.048 {+-} 0.028, R{sub 1} = 1.417 {+-} 0.061 {+-} 0.044, R{sub 2}, = 0.836 {+-} 0.037 {+-} 0.022, and F(1)|V{sub cb}| = (34.68 {+-} 0.32 {+-} 1.15) x 10{sup -3}. Using the lattice calculations for the axial form factor F(1), they extract |V{sub cb}| = (37.74 {+-} 0.35 {+-} 1.25 {+-} {sub 1.44}{sup 1.23}) x 10{sup -3}, where the third error is due to the uncertainty in F(1).
Lujan, Paul Joseph
2009-12-01
This thesis presents a measurement of the top quark mass obtained from p$\\bar{p}$ collisions at √s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector. The measurement uses a matrix element integration method to calculate a t$\\bar{t}$ likelihood, employing a Quasi-Monte Carlo integration, which enables us to take into account effects due to finite detector angular resolution and quark mass effects. We calculate a t$\\bar{t}$ likelihood as a 2-D function of the top pole mass m_{t} and Δ_{JES}, where Δ_{JES} parameterizes the uncertainty in our knowledge of the jet energy scale; it is a shift applied to all jet energies in units of the jet-dependent systematic error. By introducing Δ_{JES} into the likelihood, we can use the information contained in W boson decays to constrain Δ_{JES} and reduce error due to this uncertainty. We use a neural network discriminant to identify events likely to be background, and apply a cut on the peak value of individual event likelihoods to reduce the effect of badly reconstructed events. This measurement uses a total of 4.3 fb^{-1} of integrated luminosity, requiring events with a lepton, large E_{T}, and exactly four high-energy jets in the pseudorapidity range |η| < 2.0, of which at least one must be tagged as coming from a b quark. In total, we observe 738 events before and 630 events after applying the likelihood cut, and measure m_{t} = 172.6 ± 0.9 (stat.) ± 0.7 (JES) ± 1.1 (syst.) GeV/c^{2}, or m_{t} = 172.6 ± 1.6 (tot.) GeV/c^{2}.
Dey, B.; Meyer, C. A.; Bellis, M.; Williams, M.; Adhikari, K. P.; Adikaram, D.; Aghasyan, M.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Ball, J.; Baltzell, N. A.; Battaglieri, M.; Bedlinskiy, I.; Biselli, A. S.; Bono, J.; Boiarinov, S.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Cortes, O.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Doughty, D.; Dugger, M.; Dupre, R.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Fedotov, G.; Fegan, S.; Fleming, J. A.; Garçon, M.; Gevorgyan, N.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Glazier, D. I.; Goetz, J. T.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Hafidi, K.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hicks, K.; Ho, D.; Holtrop, M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Jenkins, D.; Jo, H. S.; Joo, K.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Koirala, S.; Kubarovsky, V.; Kuhn, S. E.; Kuleshov, S. V.; Lenisa, P.; Livingston, K.; Lu, H.; MacGregor, I. J.D.; Markov, N.; Mayer, M.; McCracken, M. E.; McKinnon, B.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Montgomery, R. A.; Moriya, K.; Moutarde, H.; Munevar, E.; Munoz Camacho, C.; Nadel-Turonski, P.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Pappalardo, L. L.; Paremuzyan, R.; Park, K.; Pasyuk, E.; Peng, P.; Phillips, J. J.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Protopopescu, D.; Puckett, A. J. R.; Rimal, D.; Ripani, M.; Ritchie, B. G.; Rizzo, A.; Rossi, P.; Roy, P.; Sabatié, F.; Saini, M. S.; Schott, D.; Schumacher, R. A.; Seder, E.; Senderovich, I.; Sharabian, Y. G.; Simonyan, A.; Smith, E. S.; Sober, D. I.; Sokhan, D.; Stepanyan, S. S.; Stoler, P.; Strakovsky, I. I.; Strauch, S.; Sytnik, V.; Taiuti, M.; Tang, W.; Tkachenko, S.; Ungaro, M.; Vernarsky, B.; Vlassov, A. V.; Voskanyan, H.; Voutier, E.; Watts, D. P.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.
2014-05-27
High-statistics measurements of differential cross sections and spin density matrix elements for the reaction γ p → Φp have been made using the CLAS detector at Jefferson Lab. We cover center-of-mass energies (√s) from 1.97 to 2.84 GeV, with an extensive coverage in the Φ production angle. The high statistics of the data sample made it necessary to carefully account for the interplay between the Φ natural lineshape and effects of the detector resolution, that are found to be comparable in magnitude. We study both the charged- (Φ → K⁺K⁻) and neutral- (Φ → K^{0}_{S}K^{0}_{L}) $K\\bar{K}$ decay modes of the Φ. Further, for the charged mode, we differentiate between the cases where the final K⁻ track is directly detected or its momentum reconstructed as the total missing momentum in the event. The two charged-mode topologies and the neutral-mode have different resolutions and are calibrated against each other. Extensive usage is made of kinematic fitting to improve the reconstructed Φ mass resolution. Our final results are reported in 10- and mostly 30-MeV-wide √s bins for the charged- and the neutral-mode, respectively. Possible effects from K⁺Λ* channels with p$K\\bar{K}$ final-states are discussed. These present results constitute the most precise and extensive Φ photoproduction measurements to date and in conjunction with the ω photoproduction results recently published by CLAS, will greatly improve our understanding of low energy vector meson photoproduction.
Black, L.P.; Kamo, S.L.; Allen, C.M.; Davis, D.W.; Aleinikoff, J.N.; Valley, J.W.; Mundil, R.; Campbell, I.H.; Korsch, R.J.; Williams, I.S.; Foudoulis, C.
2004-01-01
Precise isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) documentation is given for two new Palaeozoic zircon standards (TEMORA 2 and R33). These data, in combination with results for previously documented standards (AS3, SL13, QGNG and TEMORA 1), provide the basis for a detailed investigation of inconsistencies in 206Pb/238U ages measured by microprobe. Although these ages are normally consistent between any two standards, their relative age offsets are often different from those established by ID-TIMS. This is true for both sensitive high-resolution ion-microprobe (SHRIMP) and excimer laser ablation-inductively coupled plasma-mass spectrometry (ELA-ICP-MS) dating, although the age offsets are in the opposite sense for the two techniques. Various factors have been investigated for possible correlations with age bias, in an attempt to resolve why the accuracy of the method is worse than the indicated precision. Crystallographic orientation, position on the grain-mount and oxygen isotopic composition are unrelated to the bias. There are, however, striking correlations between the 206Pb/238U age offsets and P, Sm and, most particularly, Nd abundances in the zircons. Although these are not believed to be the primary cause of this apparent matrix effect, they indicate that ionisation of 206Pb/238U is influenced, at least in part, by a combination of trace elements. Nd is sufficiently representative of the controlling trace elements that it provides a quantitative means of correcting for the microprobe age bias. This approach has the potential to reduce age biases associated with different techniques, different instrumentation and different standards within and between laboratories. Crown Copyright ?? 2004 Published by Elsevier B.V. All rights reserved.
Shan, Xiao; Connor, J N L
2012-11-26
A previous paper by Shan and Connor (Phys. Chem. Chem. Phys. 2011, 13, 8392) reported the surprising result that four simple parametrized S matrices can reproduce the forward-angle glory scattering of the H + D(2)(v(i)=0,j(i)=0) → HD(v(f)=3,j(f)=0) + D reaction, whose differential cross section (DCS) had been computed in a state-of-the-art scattering calculation for a state-of-the-art potential energy surface. Here, v and j are vibrational and rotational quantum numbers, respectively, and the translational energy is 1.81 eV. This paper asks the question: Can we replace the analytic functions (of class C(ω)) used by Shan-Connor with simpler mathematical functions and still reproduce the forward-angle glory scattering? We first construct S matrix elements (of class C(0)) using a quadratic phase and a piecewise-continuous pre-exponential factor consisting of three pieces. Two of the pieces are constants, with one taking the value N (a real normalization constant) at small values of the total angular momentum number, J; the other piece has the value 0 at large J. These two pieces are joined at intermediate values of J by either a straight line, giving rise to the linear parametrization (denoted param L), or a quadratic curve, which defines the quadratic parametrization (param Q). We find that both param L and param Q can reproduce the glory scattering for center-of-mass reactive scattering angles, θ(R) ≲ 30°. Second, we use a piecewise-discontinuous pre-exponential factor and a quadratic phase, giving rise to a step-function parametrization (param SF) and a top-hat parametrization (param TH). We find that both param SF and param TH can reproduce the forward-angle scattering, even though these class C(-1) parametrizations are usually considered too simplistic to be useful for calculations of DCSs. We find that an ultrasimplistic param THz, which is param TH with a phase of zero, can also reproduce the glory scattering at forward angles. The S matrix elements for
NASA Astrophysics Data System (ADS)
Cao, Yong; Chu, Yuchuan; He, Xiaoming; Lin, Tao
2015-01-01
Interface problems involving the non-homogeneous flux jump condition are critical for engineering designs in the magnetostatic/electrostatic field. In applications, such as plasma simulation, we often only know the total electric quantity on the surface of the object, not the charge density distribution on the surface which appears as the non-homogeneous flux jump condition in the usual interface problems considered in the literature for the magnetostatic/electrostatic field. Based on structured meshes independent of the interface, this article proposes an iterative method that employs both the immersed finite element (IFE) method with non-homogeneous flux jump conditions and the regular finite element method with ghost nodes introduced in the object to solve the 2D interface problem for the potential field according to the given total electric quantity on the surface of the object. Numerical experiments are provided to illustrate the accuracy and efficiency of the proposed method.
Cahill, Patrick Louis; Heasman, Kevin; Jeffs, Andrew; Kuhajek, Jeanne
2013-09-01
Polygodial is a potent and selective inhibitor of ascidian metamorphosis that shows promise for controlling fouling by ascidians in bivalve aquaculture. The current study examined the potency of, and associated effects of seawater exposure on, a rosin-based soluble-matrix paint laced with 0.08-160 ng polygodial g(-1) wet paint matrix. Paint-coated surfaces were soaked in seawater for 0, 2, 4 or 12 weeks prior to screening for antifouling activity using a bioassay based on the nuisance ascidian Ciona savignyi Herdman. Mortality was greater (mean 50% lethal concentration: 5 ± 2 ng g(-1); mean 75% lethal concentration: 17 ± 4 ng g(-1)) and metamorphosis was inhibited (mean 50% anti-metamorphic concentration: 2 ± 0.4 ng g(-1); mean 75% anti-metamorphic concentration: 15 ± 10 ng g(-1)) in C. savignyi larvae exposed to polygodial-laced soluble-matrix paints, relative to control paints without polygodial. Soaking in seawater prior to testing reduced the efficacy of the formulation up to nearly 12-fold, but even after soaking for 12 weeks paints laced with polygodial at 160 ng g(-1) wet paint matrix prevented ⩾90% of the larvae of C. savignyi from completing metamorphosis. The outcome of this experiment provides a positive first step in evaluating the suitability of polygodial-laced soluble-matrix paints for use in aquaculture.
Gutiérrez-Gutiérrez, Silvia C.; Coulon, Frédéric; Jiang, Ying; Wagland, Stuart
2015-08-15
Highlights: • Samples from multiple core drills were obtained from 4× landfill sites in the UK. • Each sample analysed for rare earth elements, critical metals and valuable metals. • Two stage microwave digestion method ensuring high yield. • High quantities of copper and aluminium were observed in the soil layers of landfill. • Across 4× landfills aluminium and copper present has a value of around $400 million. - Abstract: Rare earth elements (REEs), Platinum group metals (PGMs) and other critical metals currently attract significant interest due to the high risks of supply shortage and substantial impact on the economy. Their uses in many applications have made them present in municipal solid waste (MSW) and in commercial and industrial waste (C&I), since several industrial processes produce by-products with high content of these metals. With over 4000 landfills in the UK alone, the aim of this study was to assess the existence of these critical metals within landfills. Samples collected from four closed landfills in UK were subjected to a two-step acid digestion to extract 27 metals of interest. Concentrations across the four landfill sites were 58 ± 6 mg kg{sup −1} for REEs comprising 44 ± 8 mg kg{sup −1} for light REEs, 11 ± 2 mg kg{sup −1} for heavy REEs and 3 ± 1 mg kg{sup −1} for Scandium (Sc) and 3 ± 1.0 mg kg{sup −1} of PGMs. Compared to the typical concentration in ores, these concentrations are too low to achieve a commercially viable extraction. However, content of other highly valuable metals (Al and Cu) was found in concentrations equating to a combined value across the four landfills of around $400 million, which increases the economic viability of landfill mining. Presence of critical metals will mainly depend on the type of waste that was buried but the recovery of these metals through landfill mining is possible and is economically feasible only if additional materials (plastics, paper, metallic items and other) are
NEUTRONIC REACTOR CONTROL ELEMENT
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)
NASA Astrophysics Data System (ADS)
Datta, Abhishek; Zhou, Xiang; Su, Yuzhou; Parra, Lucas C.; Bikson, Marom
2013-06-01
Objective. During transcranial electrical stimulation, current passage across the scalp generates voltage across the scalp surface. The goal was to characterize these scalp voltages for the purpose of validating subject-specific finite element method (FEM) models of current flow. Approach. Using a recording electrode array, we mapped skin voltages resulting from low-intensity transcranial electrical stimulation. These voltage recordings were used to compare the predictions obtained from the high-resolution model based on the subject undergoing transcranial stimulation. Main results. Each of the four stimulation electrode configurations tested resulted in a distinct distribution of scalp voltages; these spatial maps were linear with applied current amplitude (0.1 to 1 mA) over low frequencies (1 to 10 Hz). The FEM model accurately predicted the distinct voltage distributions and correlated the induced scalp voltages with current flow through cortex. Significance. Our results provide the first direct model validation for these subject-specific modeling approaches. In addition, the monitoring of scalp voltages may be used to verify electrode placement to increase transcranial electrical stimulation safety and reproducibility.
Ain, Khusnul; Kurniadi, Deddy; Suprijanto; Santoso, Oerip; Wibowo, Arif
2015-04-16
Back projection reconstruction has been implemented to get the dynamical image in electrical impedance tomography. However the implementation is still limited in method of adjacent data collection and circular object element model. The study aims to develop the methods of back projection as reconstruction method that has the high speed, accuracy, and flexibility, which can be used for various methods of data collection and model of the object element. The proposed method uses the forward problem solution as the operator of filtered and back projection matrix. This is done through a simulation study on several methods of data collection and various models of the object element. The results indicate that the developed method is capable of producing images, fastly and accurately for reconstruction of the various methods of data collection and models of the object element.
Gutiérrez-Gutiérrez, Silvia C; Coulon, Frédéric; Jiang, Ying; Wagland, Stuart
2015-08-01
Rare earth elements (REEs), Platinum group metals (PGMs) and other critical metals currently attract significant interest due to the high risks of supply shortage and substantial impact on the economy. Their uses in many applications have made them present in municipal solid waste (MSW) and in commercial and industrial waste (C&I), since several industrial processes produce by-products with high content of these metals. With over 4000 landfills in the UK alone, the aim of this study was to assess the existence of these critical metals within landfills. Samples collected from four closed landfills in UK were subjected to a two-step acid digestion to extract 27 metals of interest. Concentrations across the four landfill sites were 58±6mgkg(-1) for REEs comprising 44±8mgkg(-1) for light REEs, 11±2mgkg(-1) for heavy REEs and 3±1mgkg(-1) for Scandium (Sc) and 3±1.0mgkg(-1) of PGMs. Compared to the typical concentration in ores, these concentrations are too low to achieve a commercially viable extraction. However, content of other highly valuable metals (Al and Cu) was found in concentrations equating to a combined value across the four landfills of around $400 million, which increases the economic viability of landfill mining. Presence of critical metals will mainly depend on the type of waste that was buried but the recovery of these metals through landfill mining is possible and is economically feasible only if additional materials (plastics, paper, metallic items and other) are also recovered for reprocessing.
Sorte, Cascade J B; Etter, Ron J; Spackman, Robert; Boyle, Elizabeth E; Hannigan, Robyn E
2013-01-01
As the climate warms, species that cannot tolerate changing conditions will only persist if they undergo range shifts. Redistribution ability may be particularly variable for benthic marine species that disperse as pelagic larvae in ocean currents. The blue mussel, Mytilus edulis, has recently experienced a warming-related range contraction in the southeastern USA and may face limitations to northward range shifts within the Gulf of Maine where dominant coastal currents flow southward. Thus, blue mussels might be especially vulnerable to warming, and understanding dispersal patterns is crucial given the species' relatively long planktonic larval period (>1 month). To determine whether trace elemental "fingerprints" incorporated in mussel shells could be used to identify population sources (i.e. collection locations), we assessed the geographic variation in shell chemistry of blue mussels collected from seven populations between Cape Cod, Massachusetts and northern Maine. Across this ∼500 km of coastline, we were able to successfully predict population sources for over two-thirds of juvenile individuals, with almost 80% of juveniles classified within one site of their collection location and 97% correctly classified to region. These results indicate that significant differences in elemental signatures of mussel shells exist between open-coast sites separated by ∼50 km throughout the Gulf of Maine. Our findings suggest that elemental "fingerprinting" is a promising approach for predicting redistribution potential of the blue mussel, an ecologically and economically important species in the region.
Abdi, Mohammad Reza; Rezaee-Ebrahim-Saraee, Khadijeh; Fard, Mehdi Rezvani; Baradaran-Ghahfarokhi, Milad
2015-01-01
Background: This study aimed to investigate the potential health concerns of trace elements and mineral content of commonly consumed greenhouse vegetables in Isfahan, Iran. Materials and Methods: Six kinds of greenhouse vegetables namely; Raphanus sativus (Radish), Cucumis sativus (Cucumber), Solanum lycopersicum (Tomato), green Capsicum annuum (Green bell pepper), yellow C. annuum (Yellow bell pepper), and red C. annuum (Red bell pepper) were collected from Isfahan greenhouses, between December 2012 and March 2013. The vegetables were analyzed in order to determine the concentrations of trace elements and trace minerals using instrumental neutron activation analysis (INAA). Results: The results of INAA showed that the concentrations of aluminum, bromine, cobalt, rubidium and strontium of these vegetables were varied from 7.2 to 28.4 mg/kg, 0.6–11.7 mg/kg, 0.1–0.5 mg/kg, 4.2–8.4 mg/kg, and 12.0–141.0 mg/kg, respectively. The trace mineral concentrations of As, Cr, Cs, Sc, Th, and U in all of the samples were less than the defined tolerable upper intake level. Conclusion: The results of this study revealed that considering the measured trace elements and mineral content levels, Isfahan greenhouse vegetables do not impose any serious health harmful effects for individuals in the studied area due to their meal consumptions. PMID:26605243
Simon, Hélène A; Dasi, Lakshmi P; Leo, Hwa-Liang; Yoganathan, Ajit P
2007-08-01
Point-wise velocity measurements have been traditionally acquired to estimate blood damage potential induced by prosthetic heart valves with emphasis on peak values of velocity magnitude and Reynolds stresses. However, the inherently Lagrangian nature of platelet activation and hemolysis makes such measurements of limited predictive value. This study provides a refined fluid mechanical analysis, including blood element paths and stress exposure times, of the hinge flows of a CarboMedics bileaflet mechanical heart valve placed under both mitral and aortic conditions and a St Jude Medical bileaflet valve placed under aortic conditions. The hinge area was partitioned into characteristic regions based on dominant flow structures and spatio-temporal averaging was performed on the measured velocities and Reynolds shear stresses to estimate the average bulk stresses acting on blood elements transiting through the hinge. A first-order estimate of viscous stress levels and exposure times were computed. Both forward and leakage flow phases were characterized in each partition by dynamic flows dependent on subtle leaflet movements and transvalvular pressure fluctuations. Blood elements trapped in recirculation regions may experience exposure times as long as the entire forward flow phase duration. Most calculated stresses were below the accepted blood damage threshold. Estimates of the stress levels indicate that the flow conditions within the boundary layers near the hinge and leaflet walls may be more detrimental to blood cells than bulk flow conditions, while recirculation regions may promote thrombus buildup.
Nesfatin-1/NUCB2 as a Potential New Element of Sleep Regulation in Rats
Vas, Szilvia; Ádori, Csaba; Könczöl, Katalin; Kátai, Zita; Pap, Dorottya; Papp, Rege S.; Bagdy, György; Palkovits, Miklós; Tóth, Zsuzsanna E.
2013-01-01
Study Objectives Millions suffer from sleep disorders that often accompany severe illnesses such as major depression; a leading psychiatric disorder characterized by appetite and rapid eye movement sleep (REMS) abnormalities. Melanin-concentrating hormone (MCH) and nesfatin-1/NUCB2 (nesfatin) are strongly co - expressed in the hypothalamus and are involved both in food intake regulation and depression. Since MCH was recognized earlier as a hypnogenic factor, we analyzed the potential role of nesfatin on vigilance. Design We subjected rats to a 72 h-long REMS deprivation using the classic flower pot method, followed by a 3 h-long ‘rebound sleep’. Nesfatin mRNA and protein expressions as well as neuronal activity (Fos) were measured by quantitative in situ hybridization technique, ELISA and immunohistochemistry, respectively, in ‘deprived’ and ‘rebound’ groups, relative to controls sacrificed at the same time. We also analyzed electroencephalogram of rats treated by intracerebroventricularly administered nesfatin-1, or saline. Results REMS deprivation downregulated the expression of nesfatin (mRNA and protein), however, enhanced REMS during ‘rebound’ reversed this to control levels. Additionally, increased transcriptional activity (Fos) was demonstrated in nesfatin neurons during ‘rebound’. Centrally administered nesfatin-1 at light on reduced REMS and intermediate stage of sleep, while increased passive wake for several hours and also caused a short-term increase in light slow wave sleep. Conclusions The data designate nesfatin as a potential new factor in sleep regulation, which fact can also be relevant in the better understanding of the role of nesfatin in the pathomechanism of depression. PMID:23560056
NASA Technical Reports Server (NTRS)
Olson, L. E.; Dvorak, F. A.
1975-01-01
The viscous subsonic flow past two-dimensional and infinite-span swept multi-component airfoils is studied theoretically and experimentally. The computerized analysis is based on iteratively coupled boundary layer and potential flow analysis. The method, which is restricted to flows with only slight separation, gives surface pressure distribution, chordwise and spanwise boundary layer characteristics, lift, drag, and pitching moment for airfoil configurations with up to four elements. Merging confluent boundary layers are treated. Theoretical predictions are compared with an exact theoretical potential flow solution and with experimental measures made in the Ames 40- by 80-Foot Wind Tunnel for both two-dimensional and infinite-span swept wing configurations. Section lift characteristics are accurately predicted for zero and moderate sweep angles where flow separation effects are negligible.
Wu, B Y; Chan, Y C; Middendorf, A; Gu, X; Zhong, H W
2008-01-01
The electronic waste (e-waste) is increasingly flooding Asia, especially China. E-waste could precipitate a growing volume of toxic input to the local environment if it was not handed properly. This makes the evaluation of environmental impact from electronics an essentially important task for the life cycle assessment (LCA) and the end-of-life management of electronic products. This study presented a quantitative investigation on the environmental performance of typical electronics. Two types of disposed mobile phones (MPs), as a representative of consumer electronics, were evaluated in terms of toxicity potential indicator (TPI) with an assumption of worst-case scenario. It is found that the composition and the percentages of constituents in MPs are similar. More than 20 metallic elements make up 35 wt.%-40 wt.% of the total weight, of which 12 elements are identified to be highly hazardous and 12 are less harmful. With the TPI technique, the environmental performance of Pb is attributed to be 20.8 mg(-1). The total TPIs of metallic elements in the old and new type MP is 255,403 and 127,639 units, respectively, which is equivalent to the effect of releasing 6.14 and 12.28 g Pb into the environment. The average TPI of the old and new type MP is 4.1 and 4.5 mg(-1), respectively, which suggests a similar eco-efficiency per unit mass. The new model of MP is more eco-effective than the old one, which is not due to a reduction in the type of hazardous elements, but rather due to a significant miniaturization of the package with less weight. A single MP can have a considerable toxicity to the environment as referred to Pb, which suggests a major concern for the environmental impact of the total e-waste with a huge quantity and a heavy mass in China.
Jha, Pankaj; Lu, Dongsheng; Xu, Shuhua
2015-01-01
Noncoding DNA sequences (NCS) have attracted much attention recently due to their functional potentials. Here we attempted to reveal the functional roles of noncoding sequences from the point of view of natural selection that typically indicates the functional potentials of certain genomic elements. We analyzed nearly 37 million single nucleotide polymorphisms (SNPs) of Phase I data of the 1000 Genomes Project. We estimated a series of key parameters of population genetics and molecular evolution to characterize sequence variations of the noncoding genome within and between populations, and identified the natural selection footprints in NCS in worldwide human populations. Our results showed that purifying selection is prevalent and there is substantial constraint of variations in NCS, while positive selectionis more likely to be specific to some particular genomic regions and regional populations. Intriguingly, we observed larger fraction of non-conserved NCS variants with lower derived allele frequency in the genome, indicating possible functional gain of non-conserved NCS. Notably, NCS elements are enriched for potentially functional markers such as eQTLs, TF motif, and DNase I footprints in the genome. More interestingly, some NCS variants associated with diseases such as Alzheimer's disease, Type 1 diabetes, and immune-related bowel disorder (IBD) showed signatures of positive selection, although the majority of NCS variants, reported as risk alleles by genome-wide association studies, showed signatures of negative selection. Our analyses provided compelling evidence of natural selection forces on noncoding sequences in the human genome and advanced our understanding of their functional potentials that play important roles in disease etiology and human evolution.
2014-01-01
Background Immediately after renal transplantation, patients experience rapid and significant improvement of their clinical conditions and undergo considerable systemic and cellular modifications. However, some patients present a slow recovery of the renal function commonly defined as delayed graft function (DGF). Although clinically well characterized, the molecular mechanisms underlying this condition are not totally defined, thus, we are currently missing specific clinical markers to predict and to make early diagnosis of this event. Methods We investigated, using a pathway analysis approach, the transcriptomic profile of peripheral blood mononuclear cells (PBMC) from renal transplant recipients with DGF and with early graft function (EGF), before (T0) and 24 hours (T24) after transplantation. Results Bioinformatics/statistical analysis showed that 15 pathways (8 up-regulated and 7 down-regulated) and 11 pathways (5 up-regulated and 6 down-regulated) were able to identify DGF patients at T0 and T24, respectively. Interestingly, the most up-regulated pathway at both time points was NLS-bearing substrate import into nucleus, which includes genes encoding for several subtypes of karyopherins, a group of proteins involved in nucleocytoplasmic transport. Signal transducers and activators of transcription (STAT) utilize karyopherins-alpha (KPNA) for their passage from cytoplasm into the nucleus. In vitro functional analysis demonstrated that in PBMCs of DGF patients, there was a significant KPNA-mediated nuclear translocation of the phosphorylated form of STAT3 (pSTAT3) after short-time stimulation (2 and 5 minutes) with interleukin-6. Conclusions Our study suggests the involvement, immediately before transplantation, of karyopherin-mediated nuclear transport in the onset and development of DGF. Additionally, it reveals that karyopherins could be good candidates as potential DGF predictive clinical biomarkers and targets for pharmacological interventions in renal
NASA Astrophysics Data System (ADS)
Weissmann, G. S.; Hartley, A. J.; Scuderi, L. A.; Nichols, G. J.; Owen, A.; Wright, S.; Felicia, A. L.; Holland, F.; Anaya, F. M. L.
2015-12-01
Since tectonic subsidence in sedimentary basins provides the potential for long-term facies preservation into the sedimentary record, analysis of geomorphic elements in modern continental sedimentary basins is required to understand facies relationships in sedimentary rocks. We use a database of over 700 modern sedimentary basins to characterize the fluvial geomorphology of sedimentary basins. Geomorphic elements were delineated in 10 representative sedimentary basins, focusing primarily on fluvial environments. Elements identified include distributive fluvial systems (DFS), tributive fluvial systems that occur between large DFS or in an axial position in the basin, lacustrine/playa, and eolian environments. The DFS elements include large DFS (> 30 km in length), small DFS (< 30 km in length), coalesced DFS in bajada or piedmont plains, and incised DFS. Our results indicate that over 88% of fluvial deposits in the evaluated sedimentary basins are present as DFS, with tributary systems covering a small portion (1-12%) of the basin. These geomorphic elements are commonly arranged hierarchically, with the largest transverse rivers forming large DFS and smaller transverse streams depositing smaller DFS in the areas between the larger DFS. These smaller streams commonly converge between the large DFS, forming a tributary system. Ultimately, most transverse rivers become tributary to the axial system in the sedimentary basin, with the axial system being confined between transverse DFS entering the basin from opposite sides of the basin, or a transverse DFS and the edge of the sedimentary basin. If axial systems are not confined by transverse DFS, they will form a DFS. Many of the world's largest rivers are located in the axial position of some sedimentary basins. Assuming uniformitarianism, sedimentary basins from the past most likely had a similar configuration of geomorphic elements. Facies distributions in tributary positions and those on DFS appear to display
Ch'ang, L.Y.; Yang, W.K.; Myer, F.E.; Yang, D.M.
1989-06-01
Three series of recombinant DNA clones were constructed, with the bacterial chloramphenical acetyltransferase (CAT) gene as a quantitative indicator, to examine the activities of promoter and enhancer sequence elements in the 5' long terminal repeat (LTR) of murine leukemia virus (MuLV)-related proviral sequences isolated from the mouse genome. Transient CAT expression was determined in mouse NIH 3T3, human HT1080, and mink CCL64 cultured cells transfected with the LTR-CAT constructs. The 700-base pair (bp) LTRs of three polytropic MuLV-related proviral clones and the 750-bp LTRs of four modified polytropic proviral clones, in complete structures either with or without the adjacent downstream sequences, all showed very little or negligible activities for CAT expression, while ecotropic MuLV LTRs were highly active. The MuLV-related LTRs were divided into three portions and examined separately. The 3' portion of the MuLV-related LTRs that contains the CCAAC and TATAA boxes was found to be a functional promoter, being about one-half to one-third as active as the corresponding portion of the ecotropic MuLV LTRs. A MboI-Bg/II fragment, representing the distinct 190- to 200-pb inserted segment in the middle, was found to be a potential enhancer, especially when examined in combination with the simian virus 40 promoter in CCL64 cells. A PstI-MboI fragment of the 5' portion, which contains the protein-binding motifs on the enhancer segment as well as the upstream LTF sequences, showed moderate enhancer activities in CCL6 cells but was virtually inactive in NIH 3T3 cells and HT1080 cells; addition of this fragment to the ecotropic LTR-CAT constructs depressed CAT expression.
NASA Astrophysics Data System (ADS)
Bachelet, M.; Crovisier, J. L.; Stille, P.; Vuilleumier, S.; Geoffroy, V.
2009-04-01
Although underground nuclear waste repositories are not expected to be favourable places for microbial activity, one should not exclude localized action of extremophilic bacteria on some materials involved in the storage concept. Among endogenous or accidentally introduced acidophiles, some are susceptible to lead to a locally drastic decreased in pH, with potential consequences on materials corrosion. Experiments were performed with Acidithiobacillus thiooxidans on 100-125 m french reference nuclear glass SON68 grains in a mineral medium under static conditions during 60 days at 25degC. Growth medium was periodically renewed and analyzed by ICP-AES and ICP-MS spectrometry for both major, trace and ultra-trace elements. Biofilm formation was evidenced by confocal laser microscopy, staining DNA with ethidium bromide and exopolysaccharides with calcofluor white. Biofilm thickness around material grains exceeded 20 m under the chosen experimental conditions. It can be noticed that while numerous studies on biofilm formation upon interaction between Acidithiobacillus ferrooxidans and materials are found in the literature, evidence for biofilm formation is still scarce for the case of the acidophilic bacterium A. thiooxidans. Presence of biofilm is a key parameter for material alteration at the solid/solution interface in biotic systems. Indeed, various constitutive elements of materials trapped in the polyanionic polymer of biofilm may also influence the alteration process. In particular, biofilm may reduce the alteration rate of materials by forming a protective barrier at their surface (Aouad et al., 2008). In this study, glass alteration rates, determined using strontium as tracer, showed that the progressive formation of a biofilm on the surface of glass has a protective effect against its alteration. Uranium and rare earth elements (REE) are efficiently trapped in the biogenic compartment of the system (exopolysaccharides + bacterial cells). Besides, the ratio
Transient finite element method using edge elements for moving conductor
Tani, Koji; Nishio, Takayuki; Yamada, Takashi ); Kawase, Yoshihiro . Dept. of Information Science)
1999-05-01
For the next generation of high speed railway systems and automobiles new braking systems are currently under development. These braking systems take into account the eddy currents, which are produced by the movement of the conductor in the magnetic field. For their optimum design, it is necessary to know the distribution of eddy currents in the moving conductor. The finite element method (FEM) is often used to simulate them. Here, transient finite element method using edge elements for moving conductor is presented. Here the magnetic vector potential is interpolated at the upwind position and the time derivative term is discretized by the backward difference method. As a result, the system matrix becomes symmetric and the ICCG method is applicable to solve the matrix. This method is used to solve an eddy current rail brake system. The results demonstrate that this approach is suitable to solve transient problems involving movement.
Matrix Embedded Organic Synthesis
NASA Astrophysics Data System (ADS)
Kamakolanu, U. G.; Freund, F. T.
2016-05-01
In the matrix of minerals such as olivine, a redox reaction of the low-z elements occurs. Oxygen is oxidized to the peroxy state while the low-Z-elements become chemically reduced. We assign them a formula [CxHyOzNiSj]n- and call them proto-organics.
Reimann, C; Fabian, K; Schilling, J; Roberts, D; Englmaier, P
2015-12-01
Analysis of soil C and O horizon samples in a recent regional geochemical survey of Nord-Trøndelag, central Norway (752 sample sites covering 25,000 km2), identified a strong enrichment of several potentially toxic elements (PTEs) in the O horizon. Of 53 elements analysed in both materials, Cd concentrations are, on average, 17 times higher in the O horizon than in the C horizon and other PTEs such as Ag (11-fold), Hg (10-fold), Sb (8-fold), Pb (4-fold) and Sn (2-fold) are all strongly enriched relative to the C horizon. Geochemical maps of the survey area do not reflect an impact from local or distant anthropogenic contamination sources in the data for O horizon soil samples. The higher concentrations of PTEs in the O horizon are the result of the interaction of the underlying geology, the vegetation zone and type, and climatic effects. Based on the general accordance with existing data from earlier surveys in other parts of northern Europe, the presence of a location-independent, superordinate natural trend towards enrichment of these elements in the O horizon relative to the C horizon soil is indicated. The results imply that the O and C horizons of soils are different geochemical entities and that their respective compositions are controlled by different processes. Local mineral soil analyses (or published data for the chemical composition of the average continental crust) cannot be used to provide a geochemical background for surface soil. At the regional scale used here surface soil chemistry is still dominated by natural sources and processes.
Harmful potential toxic elements in greenhouse soils under long-term cultivation in Almería (Spain)
NASA Astrophysics Data System (ADS)
Joaquin Ramos-Miras, Jose; Rodríguez Martín, Jose Antonio; Boluda, Rafael; Bech, Jaume; Gil, Carlos
2014-05-01
Heavy metals (HM) are considered highly significant environmental contaminants and are the object of many scientific research works into the soil environment. Activities like agriculture or industry can increase the concentration of these contaminants in soils and waters, which can affect the food chain. Intensification of certain agricultural practices, constant and excessive use of fertilizers and phytosanitary products, and using machinery, increase the HM content in agricultural soils. Many studies have dealt with HM accumulation over time. Despite these works, the influence of long periods of time on these contents, the dynamics and evolution of these elements in agricultural soils, especially soils used for intensive farming purposes under greenhouse conditions, remain unknown to a certain extent. The western Almería region (Spain) is a very important area from both the socio-economic and agricultural viewpoints. A common practice in greenhouse agriculture is the addition of agrochemicals to soils and crops to improve nutrient supply or crop protection and disease control. Such intense agricultural activity has a strong impact, which may have negative repercussions on both these greenhouse soils and the environment. A research has been carried out to determine the total and available levels of six harmful potentially toxic elements (Cd, Cu, Pb, Ni, Zn and Co), and to assess long-term variations in the greenhouse soils of western Almeria. The results indicate that managing soils in the greenhouse preparation stage determines major changes in total and available HM contents. Furthermore, Cd, Cu and Pb enrichment in soil was observed depending on the element and years of growth.
Wu, Yuchuan; Li, Jianchang; Wu, Junjun; Morgan, Paul; Xu, Xin; Rancati, Fabio; Vallese, Stefania; Raveglia, Luca; Hotchandani, Rajeev; Fuller, Nathan; Bard, Joel; Cunningham, Kristina; Fish, Susan; Krykbaev, Rustem; Tam, Steve; Goldman, Samuel J; Williams, Cara; Mansour, Tarek S; Saiah, Eddine; Sypek, Joseph; Li, Wei
2012-01-01
Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease associated with irreversible progressive airflow limitation. Matrix metalloproteinase-12 (MMP-12) has been characterized to be one of the major proteolytic enzymes to induce airway remodeling, destruction of elastin and the aberrant remodeling of damaged alveoli in COPD and asthma. The goal of this project is to develop and identify an orally potent and selective small molecule inhibitor of MMP-12 for treatment of COPD and asthma. Syntheses and structure-activity relationship (SAR) studies of a series of dibenzofuran (DBF) sulfonamides as MMP-12 inhibitors are described. Potent inhibitors of MMP-12 with excellent selectivity against other MMPs were identified. Compound 26 (MMP118), which exhibits excellent oral efficacy in the MMP-12 induced ear-swelling inflammation and lung inflammation mouse models, had been successfully advanced into Development Track status.
Aaberg, R.L.; Burger, L.L.; Baker, D.A.; Wallo, A. III; Vazquez, G.A.; Beck, W.L.
1995-05-01
The US Department of Energy (DOE) is performing a technical analysis to support the potential development of risk-based, numerical radiological control criteria (RCC) for mixed waste from DOE operations. As part of the technical analysis, potential future radiation doses are being calculated for workers at thermal treatment facilities and members of the public residing near such facilities. This study compared two types of thermal treatment systems: a conventional combustion chamber with excess air, represented by a rotary kiln with afterburner, and an oxygen-deficient pyrolysis unit, represented by a plasma arc furnace. The purpose of the first part of this study is to estimate the partitioning for significant radionuclides and elements in the two types of thermal treatment systems. Excess-air systems are generally found to produce heavy-metal chlorides, oxides, and sulfates; plasma-arc systems tend to produce more volatile free metals. This difference causes a change in source term dominance from halide volatility to free metal volatility. Chemical thermodynamic methodology is used to estimate partitioning in the two treatment systems. The second part of the study examines how the potential radiation dose to workers handling residue materials is affected by partitioning of radionuclides at the different types of facilities.
Gonzalez, Barbara Alvarez
2010-05-01
method used to estimate the background contribution. The Matrix Element method, that was successfully used in the single top discovery analysis and many other analyses within the CDF collaboration, is the multivariate technique used in this thesis to discriminate signal from background events. With this technique is possible to calculate a probability for an event to be classified as signal or background. These probabilities are then combined into a discriminant function called the Event Probability Discriminant, EPD, which increases the sensitivity of the WH process. This method is described in detail in Chapter 7. As no evidence for the signal has been found, the results obtained with this work are presented in Chapter 8 in terms of exclusion regions as a function of the mass of the Higgs boso, taking into account the full systematics. The conclusions of this work to obtain the PhD are presnted in Chapter 9.
Han, Lanfang; Gao, Bo; Zhou, Huaidong; Xu, Dongyu; Wei, Xin; Gao, Li
2015-01-01
The alteration of hydrologic condition of Three Gorges Reservoir (TGR) after impoundment has caused numerous environmental changes. This study investigated the distribution, accumulation and potential sources of the seldom monitored trace elements (SMTEs) in sediments from three tributaries (ZY, MX and CT) and one mainstream (CJ) in TGR during different seasons. The average contents of most SMTEs excluding Sb in the winter were similar to that in the summer. For Sb, its average concentrations in the summer and winter were roughly six and three times higher than its background value, respectively. Contamination factor (CF) and geoaccumulation index (Igeo) demonstrated that most of the sediments were obviously contaminated by Sb. The enrichment factors (EF) of Ga and Sb were higher than 2.0, revealing the possible anthropogenic inputs; However, the EFs of other SMTEs were lower than 1.5, indicating the natural inputs. Correlation and principal component analysis suggested the most SMTEs were positively correlated with major elements (Cr, Mn, Cu, Zn, As, Cd and Pb) and clay contents, which implies that SMTEs had the same sources with these major metals, and the fine particles might be a major carrier for transporting SMTEs from the rivers to the TGR. PMID:26538153
Mauney, Joshua R; Volloch, Vladimir; Kaplan, David L
2005-11-01
Recently, cell-based approaches utilizing adipogenic progenitor cells for fat tissue engineering have been developed and reported to have success in promoting in vivo adipogenesis and the repair of defect sites. For autologous applications, human bone marrow-derived mesenchymal stem cells (MSCs) have been suggested as a potential cell source for adipose tissue engineering applications due to their ability to be isolated and ex vivo expanded from adult bone marrow aspirates and their versatility for pluripotent differentiation into various mesenchymal lineages including adipogenic. Due to the relatively low frequency of MSCs present within bone marrow, extensive ex vivo expansion of these cells is necessary to obtain therapeutic cell populations for tissue engineering strategies. Currently, utilization of MSCs for adipose tissue engineering is limited due to the attenuation of their adipogenic differentiation potential following extensive ex vivo expansion on conventional tissue culture plastic (TCP) substrates. In the present study, the ability of a denatured collagen type I (DC) matrix to preserve MSC adipogenic potential during ex vivo expansion was examined. Adipocyte-related markers and functions were examined in vitro in response to adipogenic culture conditions for 21 days in comparison to early passage MSCs and late passage MSCs ex vivo expanded on TCP. The results demonstrated significant preservation of the ability of late passage MSCs ex vivo expanded on the DC matrix to express adipogenic markers (fatty acid-binding protein-4, lipoprotein lipase, acyl-CoA synthetase, adipsin, facilitative glucose transporter-4, and accumulation of lipids) similar to the early passage cells and in contrast to late passage MSCs expanded on TCP. The ability of the DC matrix to preserve adipocyte-related markers and functions of MSCs following extensive ex vivo expansion represents a novel culture technique to expand functional adipogenic progenitors for tissue engineering
Ieong, Cheng Cheng; Zhou, Xue Dong; Li, Ji Yao; Li, Wei; Zhang, Ling Lin
2011-03-01
Dental caries is the most common oral diseases, and it gives a serious threat to oral and general health. Fluoride, a classic anti-caries agent, has a profound effect on caries prevention and treatment. However, fluorosis and fluoride-resistant strains limit the further application of fluoride treatment. Therefore, it is still of significant benefit to seek alternatives, bringing more effective anti-caries agents. The potential role of enamel matrix proteins(EMPs) in promoting the regeneration of periodontal tissue and inducing bone have been proved. EMPs have been successfully applied in the field of periodontal disease and dental implants in recent years. Previous researches revealed that enamel matrix proteins had an important role in the synthesis of hydroxyapatite in vitro. Some experiments about the degeneration or removal of EMP suggest that enamel matrix proteins are related to the occurrence and development of caries. Based on evidences illustrated by these experiments, this paper hypothesizes that functional peptides based on the function and structure of EMPs could promote remineralization of enamel caries, which could perform as a suitable treatment to enamel caries. The hypothesis may lead a new direction in the study on the prevention and treatment of enamel caries, and further study of the anti-caries mechanisms of EMP will enable researchers to find out the most effective anti-caries peptides, which could be developed into a bionics anti-cariogenic agent.
Aschale, Minbale; Sileshi, Yilma; Kelly-Quinn, Mary; Hailu, Dereje
2017-02-01
Due to the significantly fast urban expansion and increased industrial activities, the soils in the farms in Addis Ababa are contaminated by some toxic and potentially toxic elements (As, V, Cr, Fe, Co, Ni, Cu, B, Ba, Sr, Zn, Mn, Pb and Cd) in varying degrees. The mean concentrations of Cr, Ni, As and B in most of the soil farms were found to be higher than the maximum recommended limits. The mean concentrations of Cd, Cu, Pb, Co, Ni and Mn were found to be higher than the background soil concentrations given for uncontaminated soils. Multivariate analyses coupled with correlation analysis were used to identify possible sources. The geo-accumulation index values for Cr, Mn and Pb indicated that the farm soils were unpolluted to moderately polluted as a result of anthropogenic activities. A comprehensive environmental management strategy should be formulated by the government to measure further pollution of the farmland soil.
Simon, Aude; Iftner, Christophe; Mascetti, Joëlle; Spiegelman, Fernand
2015-03-19
The present theoretical study aims at investigating the effects of an argon matrix on the structures, energetics, dynamics, and infrared (IR) spectra of small water clusters (H2O)n (n = 1-6). The potential energy surface is obtained from a hybrid self-consistent charge density functional-based tight binding/force-field approach (SCC-DFTB/FF) in which the water clusters are treated at the SCC-DFTB level and the matrix is modeled at the FF level by a cluster consisting of ∼340 Ar atoms with a face centered cubic (fcc) structure, namely (H2O)n/Ar. With respect to a pure FF scheme, this allows a quantum description of the molecular system embedded in the matrix, along with all-atom geometry optimization and molecular dynamics (MD) simulations of the (H2O)n/Ar system. Finite-temperature IR spectra are derived from the MD simulations. The SCC-DFTB/FF scheme is first benchmarked on (H2O)Arn clusters against correlated wave function results and DFT calculations performed in the present work, and against FF data available in the literature. Regarding (H2O)n/Ar systems, the geometries of the water clusters are found to adapt to the fcc environment, possibly leading to intermolecular distortion and matrix perturbation. Several energetical quantities are estimated to characterize the water clusters in the matrix. In the particular case of the water hexamer, substitution and insertion energies for the prism, bag, and cage are found to be lower than that for the 6-member ring isomer. Finite-temperature MD simulations show that the water monomer has a quasifree rotation motion at 13 K, in agreement with experimental data. In the case of the water dimer, the only large-amplitude motion is a distortion-rotation intermolecular motion, whereas only vibration motions around the nuclei equilibrium positions are observed for clusters with larger sizes. Regarding the IR spectra, we find that the matrix environment leads to redshifts of the stretching modes and almost no shift of the
Yang, Yang; Chen, Weiping; Wang, Meie; Li, Yanling; Peng, Chi
2017-02-06
Vegetable crop consumption is one of the main sources of dietary exposure to toxic trace elements (TEs). A paired survey of soil and vegetable samples was conducted in 589 agricultural sites in the Youxian prefecture, southern China, to investigate the effect of soil factors on the accumulation of arsenic, cadmium, mercury, and lead in different vegetables. A site-specific model was developed to estimate the health risk from vegetable consumption. The TE concentration varied in different plant species, and rape can be cultivated in contaminated areas for its potential use in restricting the transfer of TE from soil to edible plant parts. The accumulation of TEs in vegetables was governed by multiple factors, mainly element interaction, metal availability (extractable CaCl2 fraction), and soil pH. Soil Zn may promote Cd accumulation in vegetables when soil Cd/Zn ratio>0.02. Cadmium is a major hazardous component. About 80.8% of the adult populations consuming locally produced vegetables had a daily Cd intake risk above the safe standard. Among investigated vegetables, radish is potentially hazardous for populations because of its high consumption rate and high Cd content but low Zn accumulation. The consumption of radish cultivated in highly acidic soil (4
Adamo, Paola; Iavazzo, Pietro; Albanese, Stefano; Agrelli, Diana; De Vivo, Benedetto; Lima, Annamaria
2014-12-01
Soil pollution in agricultural lands poses a serious threat to food safety, and suggests the need for consolidated methods providing advisory indications for soil management and crop production. In this work, the three-step extraction procedure developed by the EU Measurement and Testing Programme and two soil-to-plant transfer factors (relative to total and bioavailable concentration of elements in soil) were applied on polluted agricultural soils from southern Italy to obtain information on the retention mechanisms of metals in soils and on their level of translocation to edible vegetables. The study was carried out in the Sarno river plain of Campania, an area affected by severe environmental degradation potentially impacting the health of those consuming locally produced vegetables. Soil samples were collected in 36 locations along the two main rivers flowing into the plain. In 11 sites, lettuce plants were collected at the normal stage of consumption. According to Italian environmental law governing residential soils, and on the basis of soil background reference values for the study area, we found diffuse pollution by Be, Sn and Tl, of geogenic origin, Cr and Cu from anthropogenic sources such as tanneries and intensive agriculture, and more limited pollution by Pb, Zn and V. It was found that metals polluting soils as a result of human activities were mainly associated to residual, oxidizable and reducible phases, relatively immobile and only potentially bioavailable to plants. By contrast, the essential elements Zn and Cu showed a tendency to become more readily mobile and bioavailable as their total content in soil increased and were more easily transported to the edible parts of lettuce than other pollutants. According to our results, current soil pollution in the studied area does not affect the proportion of metals taken up by lettuce plants and there is a limited health risk incurred.
NASA Technical Reports Server (NTRS)
Zhu, Dongming; Halbig, Michael; Jaskowiak, Martha; Hurst, Janet; Bhatt, Ram; Fox, Dennis S.
2014-01-01
This paper describes recent development of environmental barrier coatings on SiC/SiC ceramic matrix composites. The creep and fatigue behavior at aggressive long-term high temperature conditions have been evaluated and highlighted. Thermal conductivity and high thermal gradient cyclic durability of environmental barrier coatings have been evaluated. The damage accumulation and complex stress-strain behavior environmental barrier coatings on SiCSiC ceramic matrix composite turbine airfoil subelements during the thermal cyclic and fatigue testing of have been also reported.
NASA Astrophysics Data System (ADS)
Lu, C.; Tang, C.; Hu, J.; Chan, Y.; Chi, C.
2011-12-01
The subtropical climate and annual average about four typhoons, combined with frequent earthquakes trigger the landslide hazards in mountainous area in Taiwan. The potential Lushan landslide area is located at a famous hotspring district of Nantou County in central Taiwan which slides frequently due to heavy rainfall during pouring rain or typhoon seasons. Lushan landslide demonstrates a typical deep-seated (up to 80 meters) creep deformation of a slate rock slope with high dip angles. Under the weathering effects, the slide surface is currently extending to the lower slope was formed by the coalescing of the joints on the upper eastern slope as well as the interface between the sandy slate and the slate on the upper western slope. In this study, we simulate the process of Lushan landslide by using PFC3D, which is conducted by adopting the 3D granular discrete element method. In this simulation, we assume the whole sliding block as an inhomogeneous layer of weaken slate. We extrapolate the slip plane depth according to the result of borehole, TDR and RIF profiles. The main landslide area is about 18 hectares and the volume is about 9 million cubic meters, which is filled with 30 thousand ball elements. The topography is represented by 25,620 wall elements based on the 5m digital elevation model. We set 9 monitoring balls on surface to monitor the velocity and run-out path. According to the field work, we defined the weak planes by the strike and dip of cleavage and joint. From our results, the run-out zone is about 40 hectares. The debris will cover whole Lushan hotspring district in 20 seconds and all rock mass will almost stop after 150 seconds. The predicted maximum velocity is about 40m/s. According to the velocity profile, we can see three and four times accelerations from monitored particles. The collision of particles during sliding and complex terrain explains the fluctuation of velocity profile with time. The numerical results of this study will provide
Roh, Seok-Seon; Park, Seung-Bae; Park, Seong-Mo; Choi, Byoung Wook; Lee, Min-Ho; Hwang, Yul-Lye; Kim, Chang Hun; Jeong, Hyun-Ah; Kim, Chang Deok
2013-01-01
Background The fibrous proteins of extracellular matrix (ECM) produced by dermal fibroblast contributes to the maintenance of connective tissue integrity. Objective This study is carried out to identify the bioactive ingredient from natural products that enhances ECM production in dermal fibroblasts. Methods Bioassay-directed fractionation was used to isolate the active ingredient from natural extracts. The effects of rasatiol (isolated from Raphanus sativus) on ECM production in primary cultured human dermal fibroblasts was investigated by enzyme linked immunosorbent assay and western blot analysis. Results Rasatiol accelerated fibroblast growth in a dose-dependent manner and increased the production of type 1 collagen, fibronectin and elastin. Phosphorylation of p42/44 extracellular signal-regulated kinase, p38 mitogen-activated protein kinase, and Akt was remarkably increased by rasatiol, indicating that enhanced ECM production is linked to the activation of intracellular signaling cascades. Conclusion These results indicate that rasatiol stimulates the fibrous components of ECM production, and may be applied to the maintenance of skin texture. PMID:24003274
Dozza, B; Lesci, I G; Duchi, S; Della Bella, E; Martini, L; Salamanna, F; Falconi, M; Cinotti, S; Fini, M; Lucarelli, E; Donati, D
2017-04-01
Demineralized bone matrix (DBM) is a natural, collagen-based, osteoinductive biomaterial. Nevertheless, there are conflicting reports on the efficacy of this product. The purpose of this study was to evaluate whether DBM collagen structure is affected by particle size and can influence DBM cytocompatibility and osteoinductivity. Sheep cortical bone was ground and particles were divided in three fractions with different sizes, defined as large (L, 1-2 mm), medium (M, 0.5-1 mm), and small (S, <0.5 mm). After demineralization, the chemical-physical analysis clearly showed a particle size-dependent alteration in collagen structure, with DBM-M being altered but not as much as DBM-S. DBM-M displayed a preferable trend in almost all biological characteristics tested, although all DBM particles revealed an optimal cytocompatibility. Subcutaneous implantation of DBM particles into immunocompromised mice resulted in bone induction only for DBM-M. When sheep MSC were seeded onto particles before implantation, all DBM particles were able to induce new bone formation with the best incidence for DBM-M and DBM-S. In conclusion, the collagen alteration in DBM-M is likely the best condition to promote bone induction in vivo. Furthermore, the choice of 0.5-1 mm particles may enable to obtain more efficient and consistent results among different research groups in bone tissue-engineering applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1019-1033, 2017.
NASA Astrophysics Data System (ADS)
Melbourne, L. A.; Griffin, J.; Schmidt, D. N.; Rayfield, E. J.
2015-02-01
Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focussed on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA), suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE-models that represent coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasizing the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.
NASA Astrophysics Data System (ADS)
Melbourne, L. A.; Griffin, J.; Schmidt, D. N.; Rayfield, E. J.
2015-10-01
Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.
Anraku, Makoto; Tabuchi, Ryo; Ifuku, Shinsuke; Ishiguro, Takako; Iohara, Daisuke; Hirayama, Fumitoshi
2015-01-01
In this study, we examined a possible use of a surface-deacetylated chitin nano-fiber (SDCH-NF) and hyaluronic acid (HA) interpolymer complex (IPC) tablet as a potential antioxidative compound in extended-release matrix tablets. The antioxidant properties of untreated chitin (UCH), SDCH-NF, and HA were examined using N-centered radicals derived from 1,1′-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). SDCH-NF and HA had acceptable scavenging abilities and were relatively efficient radical scavengers, but UCH was much less effective. The results suggest that SDCH-NF and HA could serve as scavengers of compounds related to the development of oxidative stress. An SDCH-NF/HA IPC tablet was prepared and evaluated as an extended-release tablet matrix using famotidine (FMT) as a model drug. The release of FMT from the IPC tablet (DCF-NF:HA = 1:1) was slower than that from a SDCH-NF only tablet. Turbidity measurements and X-ray diffraction (XRD) data also indicated that the optimum complexation ratio for IPC between SDCH-NF/HA is 1/1, resulting in a good relationship between turbidity or XRD of the complex and the release ratio of FMT. These results suggest that an SDCH-NF/HA tablet has the potential for use in an extended-release IPC tablet with a high antioxidant activity. PMID:26501272
Anraku, Makoto; Tabuchi, Ryo; Ifuku, Shinsuke; Ishiguro, Takako; Iohara, Daisuke; Hirayama, Fumitoshi
2015-10-16
In this study, we examined a possible use of a surface-deacetylated chitin nano-fiber (SDCH-NF) and hyaluronic acid (HA) interpolymer complex (IPC) tablet as a potential antioxidative compound in extended-release matrix tablets. The antioxidant properties of untreated chitin (UCH), SDCH-NF, and HA were examined using N-centered radicals derived from 1,1'-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). SDCH-NF and HA had acceptable scavenging abilities and were relatively efficient radical scavengers, but UCH was much less effective. The results suggest that SDCH-NF and HA could serve as scavengers of compounds related to the development of oxidative stress. An SDCH-NF/HA IPC tablet was prepared and evaluated as an extended-release tablet matrix using famotidine (FMT) as a model drug. The release of FMT from the IPC tablet (DCF-NF:HA=1:1) was slower than that from a SDCH-NF only tablet. Turbidity measurements and X-ray diffraction (XRD) data also indicated that the optimum complexation ratio for IPC between SDCH-NF/HA is 1/1, resulting in a good relationship between turbidity or XRD of the complex and the release ratio of FMT. These results suggest that an SDCH-NF/HA tablet has the potential for use in an extended-release IPC tablet with a high antioxidant activity.
Natsch, Andreas; Emter, Roger
2008-03-01
Tests for skin sensitization are required prior to the market launch of new cosmetic ingredients and in vitro tests are needed to replace the current animal tests. Protein reactivity is the common feature of skin sensitizers and it is a crucial question whether a cellular in vitro assay can detect protein reactivity of diverse test chemicals. The signaling pathway involving the repressor protein Keap1 and the transcription factor nuclear factor-erythroid 2-related factor 2, which binds to the antioxidant response element (ARE) in the promoter of many phase II detoxification genes, is a potential cellular marker because Keap1 had been shown to be covalently modified by electrophiles which leads to activation of ARE-dependent genes. To evaluate whether this regulatory pathway can be used to develop a predictive cellular in vitro test for sensitization, 96 different chemicals of known skin sensitization potential were added to Hepa1C1C7 cells and the induction of the ARE-regulated quinone reductase (QR) activity was determined. In parallel, 102 chemicals were tested on the reporter cell line AREc32, which contains an eightfold repeat of the ARE sequence upstream of a luciferase gene. Among the strong/extreme skin sensitizers 14 out of 15 and 30 out of 34 moderate sensitizers induced the ARE-dependent luciferase activity and in many cases this response was paralleled by an induction of QR activity in Hepa1C1C7 cells. Sixty percent of the weak sensitizers also induced luciferase activity, and the overall accuracy of the assay was 83 percent. Only four of 30 tested nonsensitizers induced low levels of luciferase activity, indicating a high specificity of the assay. Thus, measurement of the induction of this signaling pathway provides an interesting in vitro test to screen for the skin sensitization potential of novel chemicals.
NASA Astrophysics Data System (ADS)
Lar, U. A.; Ngozi-Chika, C. S.; Ashano, E. C.
2013-08-01
Galena mining in New Zurak, central Nigeria is currently increasing in intensity, with widespread artisanal mining taking place alongside mechanised mining. These activities are causing immeasurable damage to the environment. The prolonged human exposure and ingestion of Pb and other potentially harmful elements (PHEs) such as U, Cd, Se, Zn and As that are released from ores during these (mining) activities is a cause of great concern to populations that live in the vicinity of these mine fields. Many of the communities make their living from subsistence farming, growing food from the surroundings, and obtaining drinking water from nearby surface and sub-surface water resources. An overall assessment of the degree of contamination or toxicity of Pb and other PHEs was carried out using the indices of geoaccumulation (Igeo) and contamination factors (CFs), in the different media sampled - farmland soils, uncultivated lands, mine tailings/dumps, natural waters and vegetables. Results reveal that the mine tailings and dumps are highly contaminated with Pb and other PHEs followed in decreasing degree of contamination by the uncultivated lands, farmlands and natural waters. These findings suggest that release of Pb and other PHEs from the galena mining activity has contributed significantly to the enrichment of these elements in the surrounding environment, including the natural water bodies, and are disposed to subsequent entry into the human body through the food chain. As such these PHE accumulations pose significant risks to the environment and human health, especially of children and pregnant women who are the most vulnerable groups in the area. In order to forestall a reoccurrence of the Zamfara Pb poisoning episode in northwestern Nigeria in 2010, where more than 400 children died, the authorities concerned should ensure that mining in New Zurak is done in a more environmentally friendly manner, ensuring the maintenance of an environmental quality adequate for
Hwang, S H; Hicks, K; Ahn, J K; Nakano, T; Ahn, D S; Chang, W C; Chen, J Y; Daté, S; Ejiri, H; Fujimura, H; Fujiwara, M; Fukui, S; Gohn, W; Hotta, T; Imai, K; Ishikawa, T; Joo, K; Kato, Y; Kohri, H; Kon, Y; Lee, H S; Maeda, Y; Miyabe, M; Mibe, T; Morino, Y; Muramatsu, N; Nakatsugawa, Y; Niiyama, M; Noumi, H; Oh, Y; Ohashi, Y; Ohta, T; Oka, M; Parker, J; Rangacharyulu, C; Ryu, S Y; Sawada, T; Sugaya, Y; Sumihama, M; Tsunemi, T; Uchida, M; Ungaro, M; Yosoi, M
2012-03-02
The exclusive reaction γp→K(+)π(-)Σ(+) was measured for the first time using linearly polarized photons at beam energies from 1.85 to 2.96 GeV. Angular distributions in the rest frame of the K(+)π(-) system were fitted to extract spin-density matrix elements of the K(*0) decay. The measured parity spin asymmetry shows that natural-parity exchange is dominant in this reaction. This result clearly indicates the need for t-channel exchange of the κ(800) scalar meson.
Estimation of the coordinates of several signal sources from the algebraic properties of the matrix