WorldWideScience

Sample records for strength quadrupolar interactions

  1. TmCd quadrupolar ordering and magnetic interactions

    International Nuclear Information System (INIS)

    Aleonard, R.; Morin, P.

    1979-01-01

    The paramagnetic compound TmCd crystallizes with the CsCl-type structure. Its Jahn-Teller behavior was first observed by Luethi and coworkers. We analyze here various physical properties with a pure-harmonic-elasticity model. The structural transition between cubic and tetragonal phases is now fully described (first-order character and temperature of occurrence) as well as the magnetic susceptibility, magnetization process, specific-heat, elastic-constant, and strain data. The relevant Hamiltonian takes into account the second-order magnetoelastic coupling and the quadrupolar exchange in addition to the cubic crystal field and the Heisenberg bilinear interactions. TmCd appears to be closely related to isomorphous TmZn and completes the illustration of the competition between bilinear and quadrupolar interactions occurring in some rare-earth intermetallics. In these two compounds, the quadrupolar exchange is many times stronger than the magnetoelastic coupling and the quadrupolar ordering then drives the structural transition. This situation is opposite to that occurring in (actual) Jahn-Teller compounds

  2. Quadrupolar interactions in non-cubic crystal and related extra heat capacities. Possible effects on a sapphire bolometer

    Energy Technology Data Exchange (ETDEWEB)

    Bassou, M. [Tunis Univ. (Tunisia)]|[CEA/DSM/DRECAM/SPEC, Gif-wur-Yvette (France); Rotter, M. [Karlova Univ., Prague (Czech Republic)]|[CEA/DSM/DRECAM/SPEC, Gif-wur-Yvette (France); Bernier, M. [CEA/DSM/DRECAM/SPEC, Gif-wur-Yvette (France); Chapellier, M. [CEA/DSM/DRECAM/SPEC, Gif-wur-Yvette (France)

    1996-02-11

    It is shown that in a non-cubic crystal, the extra heat capacity due to quadrupolar interaction of nuclear spins >1/2 could be much bigger than the phonon heat capacity when the temperature decreases. The possible coupling between quadrupolar and phonon heat reservoir via paramagnetic impurities is stressed. A NMR experiment done on sapphire is presented with an evaluation of the coupling between the two reservoirs and its consequence on the performance of the bolometer. (orig.).

  3. Quadrupolar interactions in non-cubic crystal and related extra heat capacities. Possible effects on a sapphire bolometer

    International Nuclear Information System (INIS)

    Bassou, M.; Rotter, M.; Bernier, M.; Chapellier, M.

    1996-01-01

    It is shown that in a non-cubic crystal, the extra heat capacity due to quadrupolar interaction of nuclear spins >1/2 could be much bigger than the phonon heat capacity when the temperature decreases. The possible coupling between quadrupolar and phonon heat reservoir via paramagnetic impurities is stressed. A NMR experiment done on sapphire is presented with an evaluation of the coupling between the two reservoirs and its consequence on the performance of the bolometer. (orig.)

  4. The Effect of Combined Magnetic Geometries on Thermally Driven Winds. I. Interaction of Dipolar and Quadrupolar Fields

    Energy Technology Data Exchange (ETDEWEB)

    Finley, Adam J.; Matt, Sean P., E-mail: af472@exeter.ac.uk [University of Exeter (UK), Department of Physics and Astronomy, Stoker Road, Devon, Exeter, EX4 4QL (United Kingdom)

    2017-08-10

    Cool stars with outer convective envelopes are observed to have magnetic fields with a variety of geometries, which on large scales are dominated by a combination of the lowest-order fields such as the dipole, quadrupole, and octupole modes. Magnetized stellar wind outflows are primarily responsible for the loss of angular momentum from these objects during the main sequence. Previous works have shown the reduced effectiveness of the stellar wind braking mechanism with increasingly complex but singular magnetic field geometries. In this paper, we quantify the impact of mixed dipolar and quadrupolar fields on the spin-down torque using 50 MHD simulations with mixed fields, along with 10 each of the pure geometries. The simulated winds include a wide range of magnetic field strength and reside in the slow-rotator regime. We find that the stellar wind braking torque from our combined geometry cases is well described by a broken power-law behavior, where the torque scaling with field strength can be predicted by the dipole component alone or the quadrupolar scaling utilizing the total field strength. The simulation results can be scaled and apply to all main-sequence cool stars. For solar parameters, the lowest-order component of the field (dipole in this paper) is the most significant in determining the angular momentum loss.

  5. Measurements of quadrupolar interaction by perturbed angular correltion method on intercalated 2H-TaS sub(2)

    International Nuclear Information System (INIS)

    Saitovitch, H.

    1979-01-01

    This work is based on our quadrupolar interaction (QI) measurements on intercalated 2H-TaS sub(2) coumponds. As intercalating elements we used the alcalines - Li, Na, K, Cs -as well as the NH sub(3) (ammonia) and C sub(6) H sub(5) N (pyridine) molecules. The (QI) measurements were performed via the differential perturbed angular correlation (DPAC) technique, using Ta sup(181) as the probe isotope, on the hydrated and anhidrous phases of the intercalated systems. Our results happened to be in better agreement with the ionic model, one of the accepted models used to describe the intercalation process, as well as the transfered charges quantities and its distribution in the intercalated systems. And by its side the measured quantities, quadrupole interaction frequencies (QIF) and their distributions δ, contributed to support and to improve the ionic model. A strong charge dynamics between the 2H-TaS sub(2) sandwiches was observed and a relation between the (QIF) changes and amount of transfered charge (e sup(-)/Ta) was established. The attempt to specify the numerical contributions to the (QI) changes arriving from the different components of the 2H-TaS sub(2) intercalated systems put in evidence the probable orbitals involved in the systems bonds. Finally the kinetics of the intercalation process to form the 2H-TaS sub(2) (Li) sub(x) system was followed continuously by the (DPAC) measurements. (author)

  6. Quadrupolar transfer pathways

    Science.gov (United States)

    Antonijevic, Sasa; Bodenhausen, Geoffrey

    2006-06-01

    A set of graphical conventions called quadrupolar transfer pathways is proposed to describe a wide range of experiments designed for the study of quadrupolar nuclei with spin quantum numbers I = 1, 3/2, 2, 5/2, etc. These pathways, which inter alea allow one to appreciate the distinction between quadrupolar and Zeeman echoes, represent a generalization of the well-known coherence transfer pathways. Quadrupolar transfer pathways not merely distinguish coherences with different orders -2 I ⩽ p ⩽ +2 I, but allow one to follow the fate of coherences associated with single transitions that have the same coherence orderp=mIr-mIs but can be distinguished by a satellite orderq=(mIr)2-(mIs)2.

  7. Dynamic-angle spinning and double rotation of quadrupolar nuclei

    International Nuclear Information System (INIS)

    Mueller, K.T.; California Univ., Berkeley, CA

    1991-07-01

    Nuclear magnetic resonance (NMR) spectroscopy of quadrupolar nuclei is complicated by the coupling of the electric quadrupole moment of the nucleus to local variations in the electric field. The quadrupolar interaction is a useful source of information about local molecular structure in solids, but it tends to broaden resonance lines causing crowding and overlap in NMR spectra. Magic- angle spinning, which is routinely used to produce high resolution spectra of spin-1/2 nuclei like carbon-13 and silicon-29, is incapable of fully narrowing resonances from quadrupolar nuclei when anisotropic second-order quadrupolar interactions are present. Two new sample-spinning techniques are introduced here that completely average the second-order quadrupolar coupling. Narrow resonance lines are obtained and individual resonances from distinct nuclear sites are identified. In dynamic-angle spinning (DAS) a rotor containing a powdered sample is reoriented between discrete angles with respect to high magnetic field. Evolution under anisotropic interactions at the different angles cancels, leaving only the isotropic evolution of the spin system. In the second technique, double rotation (DOR), a small rotor spins within a larger rotor so that the sample traces out a complicated trajectory in space. The relative orientation of the rotors and the orientation of the larger rotor within the magnetic field are selected to average both first- and second-order anisotropic broadening. The theory of quadrupolar interactions, coherent averaging theory, and motional narrowing by sample reorientation are reviewed with emphasis on the chemical shift anisotropy and second-order quadrupolar interactions experienced by half-odd integer spin quadrupolar nuclei. The DAS and DOR techniques are introduced and illustrated with application to common quadrupolar systems such as sodium-23 and oxygen-17 nuclei in solids

  8. Dynamic-angle spinning and double rotation of quadrupolar nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, K.T. (Lawrence Berkeley Lab., CA (United States) California Univ., Berkeley, CA (United States). Dept. of Chemistry)

    1991-07-01

    Nuclear magnetic resonance (NMR) spectroscopy of quadrupolar nuclei is complicated by the coupling of the electric quadrupole moment of the nucleus to local variations in the electric field. The quadrupolar interaction is a useful source of information about local molecular structure in solids, but it tends to broaden resonance lines causing crowding and overlap in NMR spectra. Magic- angle spinning, which is routinely used to produce high resolution spectra of spin-{1/2} nuclei like carbon-13 and silicon-29, is incapable of fully narrowing resonances from quadrupolar nuclei when anisotropic second-order quadrupolar interactions are present. Two new sample-spinning techniques are introduced here that completely average the second-order quadrupolar coupling. Narrow resonance lines are obtained and individual resonances from distinct nuclear sites are identified. In dynamic-angle spinning (DAS) a rotor containing a powdered sample is reoriented between discrete angles with respect to high magnetic field. Evolution under anisotropic interactions at the different angles cancels, leaving only the isotropic evolution of the spin system. In the second technique, double rotation (DOR), a small rotor spins within a larger rotor so that the sample traces out a complicated trajectory in space. The relative orientation of the rotors and the orientation of the larger rotor within the magnetic field are selected to average both first- and second-order anisotropic broadening. The theory of quadrupolar interactions, coherent averaging theory, and motional narrowing by sample reorientation are reviewed with emphasis on the chemical shift anisotropy and second-order quadrupolar interactions experienced by half-odd integer spin quadrupolar nuclei. The DAS and DOR techniques are introduced and illustrated with application to common quadrupolar systems such as sodium-23 and oxygen-17 nuclei in solids.

  9. The effect of pressure and quadrupolar interactions on the nematic-isotropic transition properties: Numerical results for a system of prolate ellipsoids including second and fourth rank orientational order parameters

    International Nuclear Information System (INIS)

    Singh, K.

    1992-10-01

    The theory of isotropic-nematic transition described in earlier papers is applied to investigate the influence of quadrupolar interactions and pressure on the stability, ordering and thermodynamic transition properties retaining second and fourth rank orientational order parameters in the calculation for a system of hard ellipsoids of revolution characterized by its length-to-width ratio (x 0 = 2a/2b). Results are in accordance with experimental observations. (author). 9 refs, 1 tab

  10. Phase transitions of quadrupolar fluids

    International Nuclear Information System (INIS)

    OShea, S.F.; Dubey, G.S.; Rasaiah, J.C.

    1997-01-01

    Gibbs ensemble simulations are reported for Lennard-Jones particles with embedded quadrupoles of strength Q * =Q/(εσ 5 ) 1/2 =2.0 where ε and σ are the Lennard-Jones parameters. Calculations revealing the effect of the dispersive forces on the liquid endash vapor coexistence were carried out by scaling the attractive r -6 term in the Lennard-Jones pair potential by a factor λ ranging from 0 to 1. Liquid endash vapor coexistence is observed for all values of λ including λ=0 for Q * =2.0, unlike the corresponding dipolar fluid studied by van Leeuwen and Smit et al. [Phys. Rev. Lett. 71, 3991 (1993)] which showed no phase transition below λ=0.35 when the reduced dipole moment μ * =2.0. The simulation data are analyzed to estimate the critical properties of the quadrupolar fluid and their dependence on the strength λ of the dispersive force. The critical temperature and pressure show a clear quadratic dependence on λ, while the density is less confidently identified as being linear in λ. The compressibility is roughly linear in λ. copyright 1997 American Institute of Physics

  11. Modeling derivative properties and binary mixtures with CO2 using the CPA and the quadrupolar CPA equations of state

    DEFF Research Database (Denmark)

    Bjørner, Martin Gamel; Kontogeorgis, Georgios

    2016-01-01

    The cubic plus association (CPA) equation of state (EoS) is extended to include quadrupolar interactions. The quadrupolar term is based on a modification of the perturbation terms by Larsen et al. (1977) [5] for a hard sphere fluid with a symmetric point quadrupole moment. The new quadrupolar CPA......CPA can accurately correlate both the phase behaviour of CO2+hydrocarbon mixtures as well as mixtures of CO2+a self-associating compound....

  12. Plasmonic hybrid nanostructure with controlled interaction strength

    Science.gov (United States)

    Grzelak, Justyna K.; Krajnik, Bartosz; Thoreson, Mark D.; Nyga, Piotr; Shalaev, Vladimir M.; Mackowski, Sebastian

    2014-03-01

    In this report we discuss the influence of plasmon excitations in a silver island film on the fluorescence of photosynthetic complex, peridinin-chlorophyll-protein (PCP). Control of the separation between these two components is obtained by fabricating a wedge layer of silica across the substrate, with a thickness from 0 to 46 nm. Continuous variation of the silica thickness allows for gradual change of interaction strength between plasmon excitations in the metallic film and the excited states of pigments comprising photosynthetic complexes. While the largest separation between the silver film and photosynthetic complexes results in fluorescence featuring a mono-exponential decay and relatively narrow distribution of intensities, the PCP complexes placed on thinner silica spacers show biexponential fluorescence decay and significantly broader distribution of total fluorescence intensities. This broad distribution is a signature of stronger sensitivity of fluorescence enhancement upon actual parameters of a hybrid nanostructure. By gradual change of the silica spacer thickness we are able to reproduce classical distance dependence of fluorescence intensity in plasmonic hybrid nanostructures on ensemble level. Experiments carried out for different excitation wavelengths indicate that the interaction is stronger for excitations resonant with plasmon absorption in the metallic layer.

  13. General quadrupolar statistical anisotropy: Planck limits

    Energy Technology Data Exchange (ETDEWEB)

    Ramazanov, S. [Gran Sasso Science Institute (INFN), Viale Francesco Crispi 7, I-67100 L' Aquila (Italy); Rubtsov, G. [Institute for Nuclear Research of the Russian Academy of Sciences, Prospect of the 60th Anniversary of October 7a, 117312 Moscow (Russian Federation); Thorsrud, M. [Faculty of Engineering, Østfold University College, P.O. Box 700, 1757 Halden (Norway); Urban, F.R., E-mail: sabir.ramazanov@gssi.infn.it, E-mail: grisha@ms2.inr.ac.ru, E-mail: mikjel.thorsrud@hiof.no, E-mail: federico.urban@kbfi.ee [National Institute of Chemical Physics and Biophysics, Rävala 10, 10143 Tallinn (Estonia)

    2017-03-01

    Several early Universe scenarios predict a direction-dependent spectrum of primordial curvature perturbations. This translates into the violation of the statistical isotropy of cosmic microwave background radiation. Previous searches for statistical anisotropy mainly focussed on a quadrupolar direction-dependence characterised by a single multipole vector and an overall amplitude g {sub *}. Generically, however, the quadrupole has a more complicated geometry described by two multipole vectors and g {sub *}. This is the subject of the present work. In particular, we limit the amplitude g {sub *} for different shapes of the quadrupole by making use of Planck 2015 maps. We also constrain certain inflationary scenarios which predict this kind of more general quadrupolar statistical anisotropy.

  14. Spin-locking of half-integer quadrupolar nuclei in nuclear magnetic resonance of solids: second-order quadrupolar and resonance offset effects.

    Science.gov (United States)

    Ashbrook, Sharon E; Wimperis, Stephen

    2009-11-21

    Spin-locking of spin I=3/2 and I=5/2 nuclei in the presence of small resonance offset and second-order quadrupolar interactions has been investigated using both exact and approximate theoretical and experimental nuclear magnetic resonance (NMR) approaches. In the presence of second-order quadrupolar interactions, we show that the initial rapid dephasing that arises from the noncommutation of the state prepared by the first pulse and the spin-locking Hamiltonian gives rise to tensor components of the spin density matrix that are antisymmetric with respect to inversion, in addition to those symmetric with respect to inversion that are found when only a first-order quadrupolar interaction is considered. We also find that spin-locking of multiple-quantum coherence in a static solid is much more sensitive to resonance offset than that of single-quantum coherence and show that good spin-locking of multiple-quantum coherence can still be achieved if the resonance offset matches the second-order shift of the multiple-quantum coherence in the appropriate reference frame. Under magic angle spinning (MAS) conditions, and in the "adiabatic" limit, we demonstrate that rotor-driven interconversion of central-transition single- and three-quantum coherences for a spin I=3/2 nucleus can be best achieved by performing the spin-locking on resonance with the three-quantum coherence in the three-quantum frame. Finally, in the "sudden" MAS limit, we show that spin I=3/2 spin-locking behavior is generally similar to that found in static solids, except when the central-transition nutation rate matches a multiple of the MAS rate and a variety of rotary resonance phenomena are observed depending on the internal spin interactions present. This investigation should aid in the application of spin-locking techniques to multiple-quantum NMR of quadrupolar nuclei and of cross-polarization and homonuclear dipolar recoupling experiments to quadrupolar nuclei such as (7)Li, (11)B, (17)O, (23)Na, and

  15. Anisotropic magnetic phase diagram of Kondo-Lattice compound Ce3Pd20Ge6 with quadrupolar ordering

    International Nuclear Information System (INIS)

    Kitagawa, Jiro; Takeda, Naoya; Ishikawa, Masayasu; Yoshida, Toshiya; Ishiguro, Akiko; Kimura, Noriaki; Komatsubara, Takemi

    1999-01-01

    We have measured the specific heat and the electrical resistivity of Ce 3 Pd 20 Ge 6 in magnetic fields up to 4T applied along three principal directions. The compound shows the large negative magnetoresistance in the quadrupolar phase. The coefficient of the electronic specific heat and T 2 -coefficient of the electrical resistivity are considerably reduced at 4T. The magnetic phase diagram constructed from these measurements suggests the existence of a highly anisotropic interaction between the electric quadrupolar moments and the magnetic dipolar moments. (author)

  16. Complexity of generic biochemical circuits: topology versus strength of interactions

    Science.gov (United States)

    Tikhonov, Mikhail; Bialek, William

    2016-12-01

    The historical focus on network topology as a determinant of biological function is still largely maintained today, illustrated by the rise of structure-only approaches to network analysis. However, biochemical circuits and genetic regulatory networks are defined both by their topology and by a multitude of continuously adjustable parameters, such as the strength of interactions between nodes, also recognized as important. Here we present a class of simple perceptron-based Boolean models within which comparing the relative importance of topology versus interaction strengths becomes a quantitatively well-posed problem. We quantify the intuition that for generic networks, optimization of interaction strengths is a crucial ingredient of achieving high complexity, defined here as the number of fixed points the network can accommodate. We propose a new methodology for characterizing the relative role of parameter optimization for topologies of a given class.

  17. High-energy behavior of field-strength interactions

    International Nuclear Information System (INIS)

    Levin, D.N.

    1976-01-01

    It is known that spontaneously broken gauge theories are the only renormalizable theories of massive spin-one particles with mass dimension less than or equal to 4. This paper describes a search for renormalizable interactions with higher mass dimension. Specifically, we examine the high-energy behavior of a class of models which involve field-strength interactions. Power counting shows that the high-energy behavior of these models is no worse than the naively estimated high-energy behavior of a gauge theory in the U gauge. Therefore, there may be a ''soft'' symmetry-breaking mechanism (for instance, a soft divergence of an antisymmetric tensor current) which enforces renormalizable high-energy behavior in the same way that spontaneously broken gauge invariance guarantees the renormalizability of gauge theories. This hope is supported by the existence of ''gauge theories'' of strings, which describe analogous interactions of strings and field strengths. Unfortunately, this idea is tarnished by explicit calculations in which renormalizability is imposed in the form of unitarity bounds. These unitarity bounds imply that all possible field-strength couplings must be zero and that the remaining interactions describe a spontaneously broken gauge theory. Thus this result supports an earlier conjecture that gauge theories are the only renormalizable theories of massive vector bosons

  18. Second-order quadrupolar line shapes under molecular dynamics: An additional transition in the extremely fast regime.

    Science.gov (United States)

    Hung, Ivan; Wu, Gang; Gan, Zhehong

    NMR spectroscopy is a powerful tool for probing molecular dynamics. For the classic case of two-site exchange, NMR spectra go through the transition from exchange broadening through coalescence and then motional narrowing as the exchange rate increases passing through the difference between the resonance frequencies of the two sites. For central-transition spectra of half-integer quadrupolar nuclei in solids, line shape change due to molecular dynamics occurs in two stages. The first stage occurs when the exchange rate is comparable to the second-order quadrupolar interaction. The second spectral transition comes at a faster exchange rate which approaches the Larmor frequency and generally reduces the isotropic quadrupolar shift. Such a two-stage transition phenomenon is unique to half-integer quadrupolar nuclei. A quantum mechanical formalism in full Liouville space is presented to explain the physical origin of the two-stage phenomenon and for use in spectral simulations. Variable-temperature 17 O NMR of solid NaNO 3 in which the NO 3 - ion undergoes 3-fold jumps confirms the two-stage transition process. The spectra of NaNO 3 acquired in the temperature range of 173-413K agree well with simulations using the quantum mechanical formalism. The rate constants for the 3-fold NO 3 - ion jumps span eight orders of magnitude (10 2 -10 10 s -1 ) covering both transitions of the dynamic 17 O line shape. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Relativistic configuration interaction treatment of generalized oscillator strength for krypton

    International Nuclear Information System (INIS)

    Wang Huangchun; Qu Yizhi; Liu Chunhua

    2007-01-01

    A fully relativistic configuration interaction method is developed to investigate the transition energies and general oscillator strengths of the lower lying states of krypton, for both optically allowed and optically forbidden transitions. The calculated results are in agreement with the recent experimental measurements. The calculated transition energies for the 5s and 5s' transitions are 9.970 and 10.717 eV, which agree with the experimental data of 10.033 and 10.643 eV. The calculated oscillator strengths are 0.211 and 0.170, comparable with the experimental results 0.214(±0.012) and 0.194 (±0.012), respectively. The momentum transfer positions (K 2 in a.u.) of the minimum and maximum GOSs in the 4s 2 4p 6 →4s 2 4p 5 (5s + 5s') transitions are 1.105 and 2.225, comparable with the measurements results 1.24 and 2.97. (authors)

  20. Relativistic Configuration Interaction Treatment of Generalized Oscillator Strength for Krypton

    Institute of Scientific and Technical Information of China (English)

    WANG Huang-Chun; QU Yi-Zhi; LIU Chun-Hua

    2007-01-01

    A fully relativistic configuration interaction method is developed to investigate the transition energies and general oscillator strengths of the lower lying states of krypton, for both optically allowed and optically forbidden transitions. The calculated results are in agreement with the recent experimental measurements. The calculated transition energies for the 5s and 5s' transitions are 9.970 and 10.717eV, which agree with the experimental data of 10.033 and 10.643 eV. The calculated oscillator strengths are 0.211 and 0.170, comparable with the experimental results 0.214(±0.012) and 0.194 (±0.012), respectively. The momentum transfer positions ( K2 in a.u.) of the minimum and maximum GOSs in the 4s24p6 → 4s24p5 (5s + 5s') transitions are 1.105 and 2.225, comparable with the measurements results 1.24 and 2.97 [Phys. Rev. A 67 (2003) 062708].

  1. Dipolar and quadrupolar defects in a transport line

    International Nuclear Information System (INIS)

    Leleux, G.; Nghiem, P.

    1991-01-01

    The defects on a transport line of linear accelerator are studied. A transport line where the elements are influenced by the design or position defects is analyzed. Only dipolar and quadrupolar defects are considered, and the coupling betwen transversal motions are excluded. The data from the literature and those calculated by transfer matrices are compared. The defects on a line are considered from an analytical point of view. Closed optical structures are also studied [fr

  2. Effective Floquet Hamiltonian theory of multiple-quantum NMR in anisotropic solids involving quadrupolar spins: Challenges and Perspectives

    Science.gov (United States)

    Ganapathy, Vinay; Ramachandran, Ramesh

    2017-10-01

    The response of a quadrupolar nucleus (nuclear spin with I > 1/2) to an oscillating radio-frequency pulse/field is delicately dependent on the ratio of the quadrupolar coupling constant to the amplitude of the pulse in addition to its duration and oscillating frequency. Consequently, analytic description of the excitation process in the density operator formalism has remained less transparent within existing theoretical frameworks. As an alternative, the utility of the "concept of effective Floquet Hamiltonians" is explored in the present study to explicate the nuances of the excitation process in multilevel systems. Employing spin I = 3/2 as a case study, a unified theoretical framework for describing the excitation of multiple-quantum transitions in static isotropic and anisotropic solids is proposed within the framework of perturbation theory. The challenges resulting from the anisotropic nature of the quadrupolar interactions are addressed within the effective Hamiltonian framework. The possible role of the various interaction frames on the convergence of the perturbation corrections is discussed along with a proposal for a "hybrid method" for describing the excitation process in anisotropic solids. Employing suitable model systems, the validity of the proposed hybrid method is substantiated through a rigorous comparison between simulations emerging from exact numerical and analytic methods.

  3. Population transfer HMQC for half-integer quadrupolar nuclei

    International Nuclear Information System (INIS)

    Wang, Qiang; Xu, Jun; Feng, Ningdong; Deng, Feng; Li, Yixuan; Trébosc, Julien; Lafon, Olivier; Hu, Bingwen; Chen, Qun; Amoureux, Jean-Paul

    2015-01-01

    This work presents a detailed analysis of a recently proposed nuclear magnetic resonance method [Wang et al., Chem. Commun. 49(59), 6653-6655 (2013)] for accelerating heteronuclear coherence transfers involving half-integer spin quadrupolar nuclei by manipulating their satellite transitions. This method, called Population Transfer Heteronuclear Multiple Quantum Correlation (PT-HMQC), is investigated in details by combining theoretical analyses, numerical simulations, and experimental investigations. We find that compared to instant inversion or instant saturation, continuous saturation is the most practical strategy to accelerate coherence transfers on half-integer quadrupolar nuclei. We further demonstrate that this strategy is efficient to enhance the sensitivity of J-mediated heteronuclear correlation experiments between two half-integer quadrupolar isotopes (e.g., 27 Al- 17 O). In this case, the build-up is strongly affected by relaxation for small T 2 ′ and J coupling values, and shortening the mixing time makes a huge signal enhancement. Moreover, this concept of population transfer can also be applied to dipolar-mediated HMQC experiments. Indeed, on the AlPO 4 -14 sample, one still observes experimentally a 2-fold shortening of the optimum mixing time albeit with no significant signal gain in the 31 P-( 27 Al) experiments

  4. Two-dimensional nuclear magnetic resonance of quadrupolar systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuanhu [Univ. of California, Berkeley, CA (United States)

    1997-09-01

    This dissertation describes two-dimensional nuclear magnetic resonance theory and experiments which have been developed to study quadruples in the solid state. The technique of multiple-quantum magic-angle spinning (MQMAS) is extensively reviewed and expanded upon in this thesis. Specifically, MQMAS is first compared with another technique, dynamic-angle spinning (DAS). The similarity between the two techniques allows us to extend much of the DAS work to the MQMAS case. Application of MQMAS to a series of aluminum containing materials is then presented. The superior resolution enhancement through MQMAS is exploited to detect the five- and six-coordinated aluminum in many aluminosilicate glasses. Combining the MQMAS method with other experiments, such as HETCOR, greatly expands the possibility of the use of MQMAS to study a large range of problems and is demonstrated in Chapter 5. Finally, the technique switching-angle spinning (SAS) is applied to quadrupolar nuclei to fully characterize a quadrupolar spin system in which all of the 8 NMR parameters are accurately determined. This dissertation is meant to demonstrate that with the combination of two-dimensional NMR concepts and new advanced spinning technologies, a series of multiple-dimensional NMR techniques can be designed to allow a detailed study of quadrupolar nuclei in the solid state.

  5. High-resolution nuclear magnetic resonance of quadrupolar nuclei in solids

    International Nuclear Information System (INIS)

    Charpentier, Th.

    1998-01-01

    After a brief review of existing methods in high-resolution NMR of quadrupolar nuclei, the manipulation of multi-quantum coherencies by radiofrequency pulses is studied. Results are then applied to the determination of optimal conditions for performing the recently introduced multiple-quantum magic-angle experiment (MQMAS). The principles of this new method, the different pulse sequences and the data processing are described in detail. Applications on aluminum hydrates and cement pastes show the improvements of this new technique over the previous ones. In a second part, after an investigation of the Floquet theory, a new formalism has been devised for studying the behavior of a spin submitted to a strong quadrupolar interaction and radiofrequency field in a rotating sample. This formalism is then applied to a quantitative study of the phenomenon of rotational induced adiabatic transfer of coherencies (RIACT). The extension of our theoretical approach to two-dimensional experiments provides a powerful tool for quantitative analyses of MQMAS spectra. Agreement between experimental data and simulations demonstrates the reliability of our approach. Preliminary results concerning the application of MQMAS spectroscopy, using our simulation programs, to structural study of amorphous materials are presented. The third and last part presents a theoretical and experimental investigation of dipolar order in a rotating sample. Two theoretical models are described, the first for the slow spinning speed regime where an adiabatic approximation can be made, and the second for the fast spinning speed regime. (author)

  6. G×E Interaction Influences Trajectories of Hand Grip Strength

    DEFF Research Database (Denmark)

    Petersen, Inge; Pedersen, Nancy L; Rantanen, Taina

    2016-01-01

    Age-related decline in grip strength predicts later life disability, frailty, lower well-being and cognitive change. While grip strength is heritable, genetic influence on change in grip strength has been relatively ignored, with non-shared environmental influence identified as the primary contri...

  7. Analysis of the quadrupolar coupling effect on the line intensities using single-crystal nutation NMR in α-Al2O3 crystals

    International Nuclear Information System (INIS)

    Woo, Ae Ja; Cho, So Hyun; Han, Duk Young

    2000-01-01

    With 1D-nutation NMR for a spin I = 5/2 system, the relative line intensities of central and the inner- and outer-satellite transitions are calculated as functions of quadrupolar coupling ω Q and rf pulse strength ω rf . Experimentally measured line intensities including both central and satellites are used to extract the values of ω Q and ω rf from nonlinear least-squares fits. The method is illustrated in α-Al 2 O 3 crystals (ruby and corundum) with the single-crystal 27 Al nutation NMR spectra. As a result, the new feature that the rf pulse strength shows reduced effect on the satellite transition lines according to the quadrupolar coupling is discussed by using fictitious spin-1/2 operator

  8. From bipolar to quadrupolar - The collimation processes of the Cepheus A outflow

    Science.gov (United States)

    Torrelles, Jose M.; Verdes-Montenegro, Lourdes; Ho, Paul T. P.; Rodriguez, Luis F.; Canto, Jorge

    1993-01-01

    Results of new K-band observations of the (1, 1) and (2, 2) ammonia lines toward Cepheus A are reported. The lines are mapped with approximately 2 arcsec of angular resolution and 0.3 km/s of velocity resolution. A sensitivity of 10 mJy has been achieved. The observations reveal details of the spatial and kinematics structure of the ambient high-density gas. It is suggested that the interstellar high-density gas is diverting and redirecting the outflow in the sense that the quadrupolar structure of the molecular outflow is produced by the interaction with the ammonia condensationss, with Cep A-1 and Cep A-3 splitting in two halves, respectively the blue- and redshifted lobes of an east-west bipolar molecular outflow.

  9. Interaction strength combinations and the overfishing of a marine food web

    OpenAIRE

    Bascompte, Jordi; Melián, Carlos J.; Sala, Enric

    2005-01-01

    The stability of ecological communities largely depends on the strength of interactions between predators and their prey. Here we show that these interaction strengths are structured nonran- domly in a large Caribbean marine food web. Specifically, the cooccurrence of strong interactions on two consecutive levels of food chains occurs less frequently than expected by chance. Even when they occur, these strongly interacting chains are accompa- nied by strong omnivory more often than expected ...

  10. A conceptual framework for studying the strength of plant-animal mutualistic interactions.

    Science.gov (United States)

    Vázquez, Diego P; Ramos-Jiliberto, Rodrigo; Urbani, Pasquinell; Valdovinos, Fernanda S

    2015-04-01

    The strength of species interactions influences strongly the structure and dynamics of ecological systems. Thus, quantifying such strength is crucial to understand how species interactions shape communities and ecosystems. Although the concepts and measurement of interaction strength in food webs have received much attention, there has been comparatively little progress in the context of mutualism. We propose a conceptual scheme for studying the strength of plant-animal mutualistic interactions. We first review the interaction strength concepts developed for food webs, and explore how these concepts have been applied to mutualistic interactions. We then outline and explain a conceptual framework for defining ecological effects in plant-animal mutualisms. We give recommendations for measuring interaction strength from data collected in field studies based on a proposed approach for the assessment of interaction strength in plant-animal mutualisms. This approach is conceptually integrative and methodologically feasible, as it focuses on two key variables usually measured in field studies: the frequency of interactions and the fitness components influenced by the interactions. © 2015 John Wiley & Sons Ltd/CNRS.

  11. Preparing Pseudo-Pure States in a Quadrupolar Spin System Using Optimal Control

    International Nuclear Information System (INIS)

    Tan Yi-Peng; Li Jun; Zhou Xian-Yi; Peng Xin-Hua; Du Jiang-Feng; Nie Xin-Fang; Chen Hong-Wei

    2012-01-01

    Pseudo-pure state (PPS) preparation is crucial in nuclear magnetic resonance quantum computation. There have been some methods in spin-1/2 systems and a few attempts in quadrupolar spin systems. As optimal control via gradient ascent pulses engineering (GRAPE) has been widely used in quantum information science, we apply this technique to PPS preparation in quadrupolar spin systems. This approach shows an effective and fast quantum control method for both the state preparation and the realization of quantum gates in quadrupolar systems

  12. Interaction strength combinations and the overfishing of a marine food web.

    Science.gov (United States)

    Bascompte, Jordi; Melián, Carlos J; Sala, Enric

    2005-04-12

    The stability of ecological communities largely depends on the strength of interactions between predators and their prey. Here we show that these interaction strengths are structured nonrandomly in a large Caribbean marine food web. Specifically, the cooccurrence of strong interactions on two consecutive levels of food chains occurs less frequently than expected by chance. Even when they occur, these strongly interacting chains are accompanied by strong omnivory more often than expected by chance. By using a food web model, we show that these interaction strength combinations reduce the likelihood of trophic cascades after the overfishing of top predators. However, fishing selectively removes predators that are overrepresented in strongly interacting chains. Hence, the potential for strong community-wide effects remains a threat.

  13. Modelling the phase equilibria of multicomponent mixtures containing CO2, alkanes, water, and/or alcohols using the quadrupolar CPA equation of state

    DEFF Research Database (Denmark)

    Bjørner, Martin Gamel; Kontogeorgis, Georgios

    2016-01-01

    In this work, a quadrupolar cubic plus association (qCPA) equation of state is evaluated for its ability to predict the phase equilibria of multicomponent mixtures containing CO2 and alkanes, alcohols, and/or water. A single binary interaction parameter is employed in qCPA for all binary combinat...... CPA yields the best results of all the models for the prediction of dew point pressures....

  14. Nature and strength of defect interactions in cubic stabilized zirconia

    International Nuclear Information System (INIS)

    Bogicevic, A.; Wolverton, C.

    2003-01-01

    The intrinsic ordering tendencies that limit ionic conduction in doped zirconia electrolytes are fully elucidated using first-principles calculations. A detailed analysis of nearly 300 yttria- and scandia-stabilized cubic-zirconia-ordered vacancy compounds reveals a delicate balance between competing elastic and electrostatic interactions. These results explain several outstanding experimental observations and provide substantial insight needed for improving ionic conduction and enabling low-temperature operation of zirconia-based electrolytes. We show that the surprising vacancy ordering in dilute solid solutions is a consequence of repulsive electrostatic and attractive elastic interactions that balance at third-neighbor vacancy separations. In contrast, repulsive elastic vacancy-dopant interactions prevail over electrostatic attraction at all probed defect separations in YSZ and lead to very weak ordering preferences in ScSZ. The total electronic contribution to the defect interactions is shown to be strongly dominated by simple point-charge electrostatics, leaving speciation of defect ordering for a given class of aliovalent dopants to the elastic term. Thus, ion size becomes a critical parameter in controlling the ionic conductivity of doped oxide electrolytes

  15. Effect of interaction strength on robustness of controlling edge dynamics in complex networks

    Science.gov (United States)

    Pang, Shao-Peng; Hao, Fei

    2018-05-01

    Robustness plays a critical role in the controllability of complex networks to withstand failures and perturbations. Recent advances in the edge controllability show that the interaction strength among edges plays a more important role than network structure. Therefore, we focus on the effect of interaction strength on the robustness of edge controllability. Using three categories of all edges to quantify the robustness, we develop a universal framework to evaluate and analyze the robustness in complex networks with arbitrary structures and interaction strengths. Applying our framework to a large number of model and real-world networks, we find that the interaction strength is a dominant factor for the robustness in undirected networks. Meanwhile, the strongest robustness and the optimal edge controllability in undirected networks can be achieved simultaneously. Different from the case of undirected networks, the robustness in directed networks is determined jointly by the interaction strength and the network's degree distribution. Moreover, a stronger robustness is usually associated with a larger number of driver nodes required to maintain full control in directed networks. This prompts us to provide an optimization method by adjusting the interaction strength to optimize the robustness of edge controllability.

  16. Yrast-yrare interaction strength and bandcrossing frequency

    International Nuclear Information System (INIS)

    Wu, C.S.; Zeng, J.Y.

    1991-01-01

    Accurate particle-number-conserving calculation shows that in a single-j model the yrast-yrare interaction V is always strong and no periodic oscillation of V with the degree of shell filling is found, in contrast to the results obtained by the Hartree-Fock-Bogoliubov approximation. To understand the behavior of V and bandcrossing frequency ω c , the spin-alignment, seniority structure, configuration structure, and ''quasiparticle structure'' of the yrast and yrare bands are analyzed in detail. Calculation in a two-j model (high-j intruder orbits plus normal orbits of opposite parity) was also carried out to illustrate schematically that a weak yrast-yrare interaction may occur for certain single-particle level scheme. The coexistence of normal low-j orbits with high-j intruder orbits is indispensible for a sharp backbending observed in some realistic nuclei

  17. Foundations of the theory of three-dimensional quadrupolar mass spectrometry. 1

    International Nuclear Information System (INIS)

    Sheretov, Eh.P.

    1979-01-01

    The basic principles of the theory of three-dimensional quadrupolar mass spectrometry are developed. It is shown that the ''stretching'' of the electrode system of the sensor of a three-dimensional quadrupolar mass spectrometer in the direction of an axis (introduction of the system assymetry) leads to a sharp decrease of the high-frequency field effect on the particle trajectory in this direction. Presented are ratios determining the configuration of electrode systems of sensors of flight-type quadrupolar mass spectrometers. Specific features of the stability diagram for such analyzers are discussed. It is shown that the property detected makes it possible to develop new promising time-of-flight three-dimensional quadrupolar mass spectrometers

  18. A reciprocity-based formula for the capacitance with quadrupolar electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sungbo [Gachon University of Medicine and Science, Incheon (Korea, Republic of)

    2011-11-15

    A new capacitance formula for the practical design and characterization of quadrupolar electrode arrays with capacitive structures was derived based on the reciprocal theorem. The reciprocity-based capacitance formula agreed with the empirical equations established to estimate the capacitance of a single strip line or disk electrode compensating for the fringing field effect that occurs at the electrode edge. The reciprocity-based formula was applied to compute the capacitance measurable by using a quadrupolar square electrode array with a symmetric dipole-dipole configuration and was compared with the analytical equation established based on the image method assuming that the electrodes were points. The results showed that the capacitance of the quadrupolar electrodes was determined by the size of the quadrupolar electrodes relative to the separation distance between the electrodes and that the reciprocity-based capacitance formula was in agreement with the established analytical equation if the separated distance between the electrodes relative to the electrode size was large enough.

  19. A reciprocity-based formula for the capacitance with quadrupolar electrodes

    International Nuclear Information System (INIS)

    Cho, Sungbo

    2011-01-01

    A new capacitance formula for the practical design and characterization of quadrupolar electrode arrays with capacitive structures was derived based on the reciprocal theorem. The reciprocity-based capacitance formula agreed with the empirical equations established to estimate the capacitance of a single strip line or disk electrode compensating for the fringing field effect that occurs at the electrode edge. The reciprocity-based formula was applied to compute the capacitance measurable by using a quadrupolar square electrode array with a symmetric dipole-dipole configuration and was compared with the analytical equation established based on the image method assuming that the electrodes were points. The results showed that the capacitance of the quadrupolar electrodes was determined by the size of the quadrupolar electrodes relative to the separation distance between the electrodes and that the reciprocity-based capacitance formula was in agreement with the established analytical equation if the separated distance between the electrodes relative to the electrode size was large enough.

  20. Effects of Strength of Accent on an L2 Interactive Lecture Listening Comprehension Test

    Science.gov (United States)

    Ockey, Gary J.; Papageorgiou, Spiros; French, Robert

    2016-01-01

    This article reports on a study which aimed to determine the effect of strength of accent on listening comprehension of interactive lectures. Test takers (N = 21,726) listened to an interactive lecture given by one of nine speakers and responded to six comprehension items. The test taker responses were analyzed with the Rasch computer program…

  1. Dynamic strength of the interaction between lung surfactant protein D (SP-D) and saccharide ligands

    DEFF Research Database (Denmark)

    Thormann, Esben; Dreyer, Jakob K; Simonsen, Adam C

    2007-01-01

    In order to investigate the dynamic strength of the interaction between lung surfactant protein D (SP-D) and different sugars, maltose, mannose, glucose, and galactose, we have used an atomic force microscope to monitor the interaction on a single molecule scale. The experiment is performed...

  2. Integrating Micro-level Interactions with Social Network Analysis in Tie Strength Research

    DEFF Research Database (Denmark)

    Torre, Osku; Gupta, Jayesh Prakash; Kärkkäinen, Hannu

    2017-01-01

    of tie strength based on reciprocal interaction from publicly available Facebook data, and suggest that this approach could work as a basis for further tie strength studies. Our approach makes use of weak tie theory, and enables researchers to study micro-level interactions (i.e. discussions, messages......A social tie is a target for ongoing, high-level scientific debate. Measuring the tie strength in social networks has been an important topic for academic studies since Mark Granovetter's seminal papers in 1970's. However, it is still a problematic issue mainly for two reasons: 1) existing tie...... strengthening process in online social networks. Therefore, we suggest a new approach to tie strength research, which focuses on studying communication patterns (edges) more rather than actors (nodes) in a social network. In this paper we build a social network analysis-based approach to enable the evaluation...

  3. Toward a Rigorous Definition of a Strength of Any Interaction Between Bader's Atomic Basins.

    Science.gov (United States)

    Ananyev, Ivan V; Karnoukhova, Valentina A; Dmitrienko, Artem O; Lyssenko, Konstantin A

    2017-06-15

    Strength of interaction between Bader's atomic basins, enclosed by zero-flux surfaces of electron distribution, was proposed to be a measure of elastic deformation of an interaction. The set containing 53 atomic aggregate and covering all range of interaction strength (from van der Waals interactions to triple covalent bonds) was calculated by DFT and perturbation theory methods. Further analysis was performed to seek correlations between various local quantities based on electron density and effective force constants of stretching diatomic vibrations. The linear trend between effective force constants and the potential energy density at the (3, -1) critical point of electron distribution was found. This correlation was improved by the integration of the potential energy density over an interbasin zero-flux surface of electron density. Simple mechanical explanation of established trends is presented. The correlations can be further used to at least semiquantitatively compare any pair of interactions between Bader's atomic basins.

  4. Channel-facilitated molecular transport: The role of strength and spatial distribution of interactions

    Energy Technology Data Exchange (ETDEWEB)

    Uppulury, Karthik, E-mail: karthik.uppulury@gmail.com [Department of Chemistry, Texas Tech University, Lubbock, TX 79409 (United States); Kolomeisky, Anatoly B. [Department of Chemistry, Department of Chemical and Biomolecular Engineering, Center for Theoretical Biological Physics, Rice University, Houston, TX 77005 (United States)

    2016-12-20

    Highlights: • Molecular flux strongly depends on the strength of the molecule-pore interactions. • There exists an optimal molecule-pore interaction potential for maximal flux. • Volume of interactions depends inversely on the strength for maximal flux. • Stronger interactions need more number of attractive sites for maximal flux. • Channels with few special sites need more attractive sites for higher flux. - Abstract: Molecular transport across channels and pores is critically important for multiple natural and industrial processes. Recent advances in single-molecule techniques have allowed researchers to probe translocation through nanopores with unprecedented spatial and temporal resolution. However, our understanding of the mechanisms of channel-facilitated molecular transport is still not complete. We present a theoretical approach that investigates the role of molecular interactions in the transport through channels. It is based on the discrete-state stochastic analysis that provides a fully analytical description of this complex process. It is found that a spatial distribution of the interactions strongly influences the translocation dynamics. We predict that there is the optimal distribution that leads to the maximal flux through the channel. It is also argued that the channel transport depends on the strength of the molecule-pore interactions, on the shape of interaction potentials and on the relative contributions of entrance and diffusion processes in the system. These observations are discussed using simple physical-chemical arguments.

  5. Channel-facilitated molecular transport: The role of strength and spatial distribution of interactions

    International Nuclear Information System (INIS)

    Uppulury, Karthik; Kolomeisky, Anatoly B.

    2016-01-01

    Highlights: • Molecular flux strongly depends on the strength of the molecule-pore interactions. • There exists an optimal molecule-pore interaction potential for maximal flux. • Volume of interactions depends inversely on the strength for maximal flux. • Stronger interactions need more number of attractive sites for maximal flux. • Channels with few special sites need more attractive sites for higher flux. - Abstract: Molecular transport across channels and pores is critically important for multiple natural and industrial processes. Recent advances in single-molecule techniques have allowed researchers to probe translocation through nanopores with unprecedented spatial and temporal resolution. However, our understanding of the mechanisms of channel-facilitated molecular transport is still not complete. We present a theoretical approach that investigates the role of molecular interactions in the transport through channels. It is based on the discrete-state stochastic analysis that provides a fully analytical description of this complex process. It is found that a spatial distribution of the interactions strongly influences the translocation dynamics. We predict that there is the optimal distribution that leads to the maximal flux through the channel. It is also argued that the channel transport depends on the strength of the molecule-pore interactions, on the shape of interaction potentials and on the relative contributions of entrance and diffusion processes in the system. These observations are discussed using simple physical-chemical arguments.

  6. Gravitational quadrupolar coupling to equivalence principle test masses: the general case

    International Nuclear Information System (INIS)

    Lockerbie, N A

    2002-01-01

    This paper discusses the significance of the quadrupolar gravitational force in the context of test masses destined for use in equivalence principle (EP) experiments, such as STEP and MICROSCOPE. The relationship between quadrupolar gravity and rotational inertia for an arbitrary body is analysed, and the special, gravitational, role of a body's principal axes of inertia is revealed. From these considerations the gravitational quadrupolar force acting on a cylindrically symmetrical body, due to a point-like attracting source mass, is derived in terms of the body's mass quadrupole tensor. The result is shown to be in agreement with that obtained from MacCullagh's formula (as the starting point). The theory is then extended to cover the case of a completely arbitrary solid body, and a compact formulation for the quadrupolar force on such a body is derived. A numerical example of a dumb-bell's attraction to a local point-like gravitational source is analysed using this theory. Close agreement is found between the resulting quadrupolar force on the body and the difference between the net and the monopolar forces acting on it, underscoring the utility of the approach. A dynamical technique for experimentally obtaining the mass quadrupole tensors of EP test masses is discussed, and a means of validating the results is noted

  7. Quadrupolar order, hidden octupolar order and tiny magnetic moment in URu2Si2

    International Nuclear Information System (INIS)

    Tsuruta, Atsushi; Matsuura, Tamifusa; Kuroda, Yoshihiro

    2000-01-01

    Possible orders in URu 2 Si 2 are investigated using a two-channel degenerate Anderson model. The ground state of uranium ions is the non-Kramers quadrupolar doublet Γ 5 with (5f) 2 , and its relevant excited state is the Kramers dipolar doublet Γ 7 with (5f) 1 . These states mix with each other via conduction electrons. At low temperatures, the system forms renormalized bands with both quadrupole and dipole degrees of freedom due to the quadrupolar Kondo effect which slightly mixes quadrupolar Γ 5 , a primary state of uranium ions, with dipolar Γ 7 . At a certain low temperature, conduction electrons in the renormalized bands undergo quadrupolar ordering with a large quadrupolar moment. At a further lower temperature, octupolar ordering occurs, accompanied by a tiny dipolar moment which is attributed to the property of the renormalized bands with primarily the Γ 5 -character slightly mixed with the Γ 7 -character. These phenomena are well described by the 1/N-expansion method with pseudo-fermions for the non-Kramers doublet Γ 5 and slave bosons for the Kramers doublet Γ 7 . (author)

  8. Scaling laws and universality for the strength of genetic interactions in yeast

    Science.gov (United States)

    Velenich, Andrea; Dai, Mingjie; Gore, Jeff

    2012-02-01

    Genetic interactions provide a window to the organization of the thousands of biochemical reactions in living cells. If two mutations affect unrelated cellular functions, the fitness effects of their combination can be easily predicted from the two separate fitness effects. However, because of interactions, for some pairs of mutations their combined fitness effect deviates from the naive prediction. We study genetic interactions in yeast cells by analyzing a publicly available database containing experimental growth rates of 5 million double mutants. We show that the characteristic strength of genetic interactions has a simple power law dependence on the fitness effects of the two interacting mutations and that the probability distribution of genetic interactions is a universal function. We further argue that the strength of genetic interactions depends only on the fitness effects of the interacting mutations and not on their biological origin in terms of single point mutations, entire gene knockouts or even more complicated physiological perturbations. Finally, we discuss the implications of the power law scaling of genetic interactions on the ruggedness of fitness landscapes and the consequent evolutionary dynamics.

  9. Interaction-Strength Interpolation Method for Main-Group Chemistry : Benchmarking, Limitations, and Perspectives

    NARCIS (Netherlands)

    Fabiano, E.; Gori-Giorgi, P.; Seidl, M.W.J.; Della Sala, F.

    2016-01-01

    We have tested the original interaction-strength-interpolation (ISI) exchange-correlation functional for main group chemistry. The ISI functional is based on an interpolation between the weak and strong coupling limits and includes exact-exchange as well as the Görling–Levy second-order energy. We

  10. Spin-locking of half-integer quadrupolar nuclei in NMR of solids: The far off-resonance case.

    Science.gov (United States)

    Odedra, Smita; Wimperis, Stephen

    Spin-locking of spin I=3/2 and I=5/2 nuclei in the presence of large resonance offsets has been studied using both approximate and exact theoretical approaches and, in the case of I=3/2, experimentally. We show the variety of coherences and population states produced in a far off-resonance spin-locking NMR experiment (one consisting solely of a spin-locking pulse) and how these vary with the radiofrequency field strength and offset frequency. Under magic angle spinning (MAS) conditions and in the "adiabatic limit", these spin-locked states acquire a time dependence. We discuss the rotor-driven interconversion of the spin-locked states, using an exact density matrix approach to confirm the results of the approximate model. Using conventional and multiple-quantum filtered spin-locking 23 Na (I=3/2) NMR experiments under both static and MAS conditions, we confirm the results of the theoretical calculations, demonstrating the applicability of the approximate theoretical model to the far off-resonance case. This simplified model includes only the effects of the initial rapid dephasing of coherences that occurs at the start of the spin-locking period and its success in reproducing both experimental and exact simulation data indicates that it is this dephasing that is the dominant phenomenon in NMR spin-locking of quadrupolar nuclei, as we have previously found for the on-resonance and near-resonance cases. Potentially, far off-resonance spin-locking of quadrupolar nuclei could be of interest in experiments such as cross polarisation as a consequence of the spin-locking pulse being applied to a better defined initial state (the thermal equilibrium bulk magnetisation aligned along the z-axis) than can be created in a powdered solid with a selective radiofrequency pulse, where the effect of the pulse depends on the orientation of the individual crystallites. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Solid state nuclear magnetic resonance studies of cross polarization from quadrupolar nuclei

    Energy Technology Data Exchange (ETDEWEB)

    De Paul, Susan M. [Univ. of California, Berkeley, CA (United States)

    1997-08-01

    The development of solid-state Nuclear Magnetic Resonance (NMR) has, to a large extent, focused on using spin-1/2 nuclei as probes to investigate molecular structure and dynamics. For such nuclei, the technique of cross polarization is well-established as a method for sensitivity enhancement. However, over two-thirds of the nuclei in the periodic table have a spin-quantum number greater than one-half and are known as quadrupolar nuclei. Such nuclei are fundamental constituents of many inorganic materials including minerals, zeolites, glasses, and gels. It is, therefore, of interest to explore the extent to which polarization can be transferred from quadrupolar nuclei. In this dissertation, solid-state NMR experiments involving cross polarization from quadrupolar nuclei to spin-1/2 nuclei under magic-angle spinning (MAS) conditions are investigated in detail.

  12. Numerical evidence for quadrupolar-octopolar order in RETM{sub 2}(Al,Zi){sub 20}

    Energy Technology Data Exchange (ETDEWEB)

    Attig, Jan [Institute for Theoretical Physics, University of Cologne (Germany); Tse, Darrell; Lee, Eric Kin-Ho; Paramekanti, Arun; Kim, Yong Baek [Department of Physics, University of Toronto, ON (Canada)

    2016-07-01

    Motivated by recent experiments on materials of the type RETM{sub 2}(Al,Zi){sub 20} (where RE is a rare earth and TM a transition metal element) we investigate a minimal model for the pseudo-spin degrees of freedom of the rare earth ions. The model is described by J1-J2 pseudo-spin interactions in three-dimensions where the XY part models quadrupolar order and the Ising part models octopolar order. We use various computational methods such as simulating annealing to find the zero temperature phase digram and investigate further by using single-spin flip Monte Carlo simulations for finite temperature. One notable finding is the existence of non-coplanar spiral ordering of pseudo-spins, which may explain some of the experimental data on the electronic ordering in RETM{sub 2}(Al,Zi){sub 20}.

  13. Simulation of transverse beam splitting using time-dependent dipolar or quadrupolar kicks

    CERN Document Server

    Capoani, Federico

    2017-01-01

    Two simple systems with high relevance for accelerator physics have been studied in detail in the context of this Summer Student Project. These systems describe the motion under the influence of detuning with amplitude due to non-linear magnets and an external, time-dependent force of dipolar or quadrupolar nature.Two simple systems with high relevance for accelerator physics have been studied in detail in the context of this Summer Student Project. These systems describe the motion under the influence of detuning with amplitude due to non-linear magnets and an external, time-dependent force of dipolar or quadrupolar nature.

  14. Nonlinear susceptibility: A direct test of the quadrupolar Kondo effect in UBe13

    International Nuclear Information System (INIS)

    Ramirez, A.P.; Chandra, P.; Coleman, P.; Fisk, Z.; Smith, J.L.; Ott, H.R.

    1994-01-01

    We present the nonlinear susceptibility as a direct test of the quadrupolar Kondo scenario for heavy fermion behavior, and apply it to the case of cubic crystal-field symmetry. Within a single-ion model we compute the nonlinear susceptibility resulting from low-lying Γ 3 (5f 2 ) and Kramers (5f 3 ) doublets. We find that nonlinear susceptibility measurements on single-crystal UBe 13 are inconsistent with a quadrupolar (5f 2 ) ground state of the uranium ion; the experimental data indicate that the low-lying magnetic excitations of UBe 13 are predominantly dipolar in character

  15. Reduction of the Glauber amplitude for electron impact rotational excitation of quadrupolar molecular ions

    International Nuclear Information System (INIS)

    Mathur, K.C.; Gupta, G.P.; Pundir, R.S.

    1981-06-01

    A reduction of the Glauber amplitude for the rotational excitation of pure quadrupolar molecular ions by electron impact is presented in a form suitable for numerical evaluation. The differential cross-section is expressed in terms of one dimensional integrals over impact parameter. (author)

  16. Gravitational quadrupolar coupling to equivalence principle test masses: the general case

    CERN Document Server

    Lockerbie, N A

    2002-01-01

    This paper discusses the significance of the quadrupolar gravitational force in the context of test masses destined for use in equivalence principle (EP) experiments, such as STEP and MICROSCOPE. The relationship between quadrupolar gravity and rotational inertia for an arbitrary body is analysed, and the special, gravitational, role of a body's principal axes of inertia is revealed. From these considerations the gravitational quadrupolar force acting on a cylindrically symmetrical body, due to a point-like attracting source mass, is derived in terms of the body's mass quadrupole tensor. The result is shown to be in agreement with that obtained from MacCullagh's formula (as the starting point). The theory is then extended to cover the case of a completely arbitrary solid body, and a compact formulation for the quadrupolar force on such a body is derived. A numerical example of a dumb-bell's attraction to a local point-like gravitational source is analysed using this theory. Close agreement is found between th...

  17. Formation of quadrupolar phase in non-Heisenberg ferromagnets with half-integer spin

    International Nuclear Information System (INIS)

    Fridman, Yu.A.; Kosmachev, O.A.; Spirin, D.V.

    2005-01-01

    Possibility of realization of quadrupolar phase in non-Heisenberg ferromagnet with magnetic ion spin 32 is studied. It is shown that such phase state exists only in ferromagnets with high value of biquadratic exchange when external magnetic field is not applied. Phase diagram of the system is built

  18. Induced quadrupolar singlet ground state of praseodymium in a modulated pyrochlore

    Science.gov (United States)

    van Duijn, J.; Kim, K. H.; Hur, N.; Ruiz-Bustos, R.; Adroja, D. T.; Bridges, F.; Daoud-Aladine, A.; Fernandez-Alonso, F.; Wen, J. J.; Kearney, V.; Huang, Q. Z.; Cheong, S.-W.; Perring, T. G.; Broholm, C.

    2017-09-01

    The complex structure and magnetism of Pr2 -xBixRu2O7 was investigated by neutron scattering and extended x-ray absorption fine structure. Pr has an approximate doublet ground state and the first excited state is a singlet. While the B -site (Ru) is well ordered throughout, this is not the case for the A -site (Pr/Bi). A broadened distribution for the Pr-O2 bond length at low temperature indicates the Pr environment varies from site to site even for x =0 . The environment about the Bi site is highly disordered ostensibly due to the 6 s lone pairs on Bi3 +. Correspondingly, we find that the non-Kramers doublet ground-state degeneracy, otherwise anticipated for Pr in the pyrochlore structure, is lifted so as to produce a quadrupolar singlet ground state with a spatially varying energy gap. For x =0 , below TN, the Ru sublattice orders antiferromagnetically, with propagation vector k =(0 ,0 ,0 ) as for Y2Ru2O7 . No ordering associated with the Pr sublattice is observed down to 100 mK. The low-energy magnetic response of Pr2 -xBixRu2O7 features a broad spectrum of magnetic excitations associated with inhomogeneous splitting of the Pr quasidoublet ground state. For x =0 (x =0.97 ), the spectrum is temperature dependent (independent). It appears disorder associated with Bi alloying enhances the inhomogeneous Pr crystal-field level splitting so that intersite interactions become irrelevant for x =0.97 . The structural complexity for the A -site may be reflected in the hysteretic uniform magnetization of B -site ruthenium in the Néel phase.

  19. Water's Interfacial Hydrogen Bonding Structure Reveals the Effective Strength of Surface-Water Interactions.

    Science.gov (United States)

    Shin, Sucheol; Willard, Adam P

    2018-06-05

    We combine all-atom molecular dynamics simulations with a mean field model of interfacial hydrogen bonding to analyze the effect of surface-water interactions on the structural and energetic properties of the liquid water interface. We show that the molecular structure of water at a weakly interacting ( i.e., hydrophobic) surface is resistant to change unless the strength of surface-water interactions are above a certain threshold. We find that below this threshold water's interfacial structure is homogeneous and insensitive to the details of the disordered surface, however, above this threshold water's interfacial structure is heterogeneous. Despite this heterogeneity, we demonstrate that the equilibrium distribution of molecular orientations can be used to quantify the energetic component of the surface-water interactions that contribute specifically to modifying the interfacial hydrogen bonding network. We identify this specific energetic component as a new measure of hydrophilicity, which we refer to as the intrinsic hydropathy.

  20. Static quadrupolar susceptibility for a Blume–Emery–Griffiths model based on the mean-field approximation

    Energy Technology Data Exchange (ETDEWEB)

    Pawlak, A., E-mail: pawlak@amu.edu.pl [Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61–614 Poznań (Poland); Gülpınar, G. [Department of Physics, Dokuz Eylül University, 35160 İzmir (Turkey); Erdem, R. [Department of Physics, Akdeniz University, 07058 Antalya (Turkey); Ağartıoğlu, M. [Institute of Science, Dokuz Eylül University, 35160 İzmir (Turkey)

    2015-12-01

    The expressions for the dipolar and quadrupolar susceptibilities are obtained within the mean-field approximation in the Blume–Emery–Griffiths model. Temperature as well as crystal field dependences of the susceptibilities are investigated for two different phase diagram topologies which take place for K/J=3 and K/J=5.0.Their behavior near the second and first order transition points as well as multi-critical points such as tricritical, triple and critical endpoint is presented. It is found that in addition to the jumps connected with the phase transitions there are broad peaks in the quadrupolar susceptibility. It is indicated that these broad peaks lie on a prolongation of the first-order line from a triple point to a critical point ending the line of first-order transitions between two distinct paramagnetic phases. It is argued that the broad peaks are a reminiscence of very strong quadrupolar fluctuations at the critical point. The results reveal the fact that near ferromagnetic–paramagnetic phase transitions the quadrupolar susceptibility generally shows a jump whereas near the phase transition between two distinct paramagnetic phases it is an edge-like. - Highlights: • MFA calculation of the quadrupolar and dipolar susceptibility in BEG model is given • The crystal-field variation of susceptibilities near the multi-critical points is examined • There are broad peaks in the quadrupolar susceptibility in the vicinity of CP • These maxima are remembrances of the very strong quadrupolar Fluctuations.

  1. Strength of Drug–Polymer Interactions: Implications for Crystallization in Dispersions

    Energy Technology Data Exchange (ETDEWEB)

    Mistry, Pinal; Suryanarayanan, Raj

    2016-09-07

    We investigated the influence of the strength of drug–polymer interactions on the crystallization behavior of a model drug in amorphous solid dispersions (ASDs). Ketoconazole ASDs were prepared with each poly(acrylic acid), poly(2-hydroxyethyl methacrylate), and polyvinylpyrrolidone. Over a wide temperature range in the supercooled region, the α-relaxation time was obtained, which provided a measure of molecular mobility. Isothermal crystallization studies were performed in the same temperature interval using either a synchrotron (for low levels of crystallinity) or a laboratory X-ray (for crystallization kinetics) source. The stronger the drug–polymer interaction, the longer was the delay in crystallization onset time, indicating an increase in physical stability. Stronger drug–polymer interactions also translated to a decrease in the magnitude of the crystallization rate constant. In amorphous ketoconazole as well as in the dispersions, the coupling coefficient, a measure of the extent of coupling between relaxation and crystallization times was ~0.5. This value was unaffected by the strength of drug–polymer interactions. On the basis of these results, the crystallization times in ASDs were predicted at temperatures very close to Tg, using the coupling coefficient experimentally determined for amorphous ketoconazole. The predicted and experimental crystallization times were in good agreement, indicating the usefulness of the model.

  2. RKKY interaction between Ce ions in CexLa1-xB6

    International Nuclear Information System (INIS)

    Schlottmann, P.

    2000-01-01

    Ce ions in (Ce x La 1-x )B 6 have a Γ 8 ground multiplet, which is fourfold degenerate and has orbital and spin content. The interaction between Ce ions is of the Ruderman-Kittel-Kasuya-Yosida (RKKY) type, which competes with the Kondo screening. The conduction states of the compound are described by three approximately ellipsoidal pockets centered at the X points of the cubic lattice. The RKKY interaction is calculated considering the interference of the three pockets. The interaction strength strongly depends on the relative position of the ions, as well as on the relative orientation of the line joining two ions to the cubic crystalline field axis. The sixteen states of a pair of Ce ions are split by the RKKY interaction into a singlet, a triplet, and a twelvefold degenerate level. The ground state is always either a singlet or a triplet, depending on the sign of the interaction. Using the exact Bethe ansatz solution of a model for a pair of interacting impurities with Γ 8 ground multiplet, we calculate the occupation of the levels, the magnetic-field susceptibility, the specific-heat γ coefficient, and the Wilson ratio for the ground state as a function of the ratio of the RKKY coupling strength to the Kondo temperature along the main crystallographic directions. As a consequence of the RKKY splitting a pair of impurities always has a quadrupolar moment. The implication of the interactions on the quadrupolar order of CeB 6 is also discussed

  3. Interactive effects of music tempi and intensities on grip strength and subjective affect.

    Science.gov (United States)

    Karageorghis, C I; Cheek, P; Simpson, S D; Bigliassi, M

    2018-03-01

    Pretask music is widely used by athletes albeit there is scant empirical evidence to support its use. The present study extended a line of work into pretask music by examining the interactive effects of music tempo and intensity (volume) on the performance of a simple motor skill and subjective affect. A 2 × 2 within-subjects factorial design was employed with an additional no-music control, the scores from which were used as a covariate. A sample of 52 male athletes (M age  = 26.1 ± 4.8 years) was exposed to five conditions: fast/loud (126 bpm/80 dBA), fast/quiet (126 bpm/70 dBA), slow/loud (87 bpm/80 dBA), slow/quiet (87 bpm/70 dBA) music, and a no-music control. Dependent variables were grip strength, measured with a handgrip dynamometer, and subjective affect, assessed by use of the Affect Grid. The tempo and intensity components of music had interactive effects for grip strength but only main effects for subjective affect. Fast-tempo music played at a high intensity yielded the highest grip strength, while fast-tempo music played at a low-intensity resulted in much lower grip strength (M diff.  = -1.11 Force kg). For affective valence, there were main effects of tempo and intensity, with fast and loud music yielding the highest scores. For affective arousal, there was no difference between tempi although there was between intensities, with the high-intensity condition yielding higher scores. The present findings indicate the utility of fast/loud pretask music in enhancing affective valence and arousal in preparation for a simple or gross motor task. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Interaction of radionickel with diatomite as a function of pH, ionic strength and temperature

    International Nuclear Information System (INIS)

    Xue Wang

    2013-01-01

    Sequestration of Ni(II) on diatomite as a function of reaction time, pH, ionic strength, foreign ions and temperature were investigated by batch sorption technique. The results indicated that the sorption of Ni(II) on diatomite was quickly in the first contact time of 2 h and then slowly with increasing contact time. The interaction of Ni(II) with diatomite was strongly pH- and ionic strength-dependent at low pH values (i.e., which was dominated by ion exchange or outer-sphere surface complexation), while the pH-dependent and ionic strength-independent sorption at high pH suggested that inner-sphere or multinuclear surface complexation was the main sorption mechanism. With increasing temperature, the sorption of Ni(II) on diatomite increased and the experimental data were well fitted by Langmuir model. The sorption samples at pH 6.8 and 10.0 were also characterized by XPS spectroscopy, and the results suggested that Si atoms also participated in Ni(II) sorption on diatomite. The results are important to evaluate the physicochemical behavior of Ni(II) and other similar radionuclides and heavy metal ions in the environment. (author)

  5. Interaction strength between different grazers and macroalgae mediated by ocean acidification over warming gradients.

    Science.gov (United States)

    Sampaio, E; Rodil, I F; Vaz-Pinto, F; Fernández, A; Arenas, F

    2017-04-01

    Since the past century, rising CO 2 levels have led to global changes (ocean warming and acidification) with subsequent effects on marine ecosystems and organisms. Macroalgae-herbivore interactions have a main role in the regulation of marine community structure (top-down control). Gradients of warming prompt complex non-linear effects on organism metabolism, cascading into altered trophic interactions and community dynamics. However, not much is known on how will acidification and grazer assemblage composition shape these effects. Within this context, we aimed to assess the combined effects of warming gradients and acidification on macroalgae-herbivore interactions, using three cosmopolitan species, abundant in the Iberian Peninsula and closely associated in nature: the amphipod Melita palmata, the gastropod Gibbula umbilicalis, and the green macroalga Ulva rigida. Under two CO 2 treatments (ΔCO 2 ≃ 450 μatm) across a temperature gradient (13.5, 16.6, 19.9 and 22.1 °C), two mesocosm experiments were performed to assess grazer consumption rates and macroalgae-herbivore interaction, respectively. Warming (Experiment I and II) and acidification (Experiment II) prompted negative effects in grazer's survival and species-specific differences in consumption rates. M. palmata was shown to be the stronger grazer per biomass (but not per capita), and also the most affected by climate stressors. Macroalgae-herbivore interaction strength was markedly shaped by the temperature gradient, while simultaneous acidification lowered thermal optimal threshold. In the near future, warming and acidification are likely to strengthen top-down control, but further increases in disturbances may lead to bottom-up regulated communities. Finally, our results suggest that grazer assemblage composition may modulate future macroalgae-herbivore interactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. High-resolution nuclear magnetic resonance of quadrupolar nuclei in solids; Resonance magnetique nucleaire haute-resolution des noyaux quadrupolaires dans les solides

    Energy Technology Data Exchange (ETDEWEB)

    Charpentier, Th

    1998-10-23

    After a brief review of existing methods in high-resolution NMR of quadrupolar nuclei, the manipulation of multi-quantum coherencies by radiofrequency pulses is studied. Results are then applied to the determination of optimal conditions for performing the recently introduced multiple-quantum magic-angle experiment (MQMAS). The principles of this new method, the different pulse sequences and the data processing are described in detail. Applications on aluminum hydrates and cement pastes show the improvements of this new technique over the previous ones. In a second part, after an investigation of the Floquet theory, a new formalism has been devised for studying the behavior of a spin submitted to a strong quadrupolar interaction and radiofrequency field in a rotating sample. This formalism is then applied to a quantitative study of the phenomenon of rotational induced adiabatic transfer of coherencies (RIACT). The extension of our theoretical approach to two-dimensional experiments provides a powerful tool for quantitative analyses of MQMAS spectra. Agreement between experimental data and simulations demonstrates the reliability of our approach. Preliminary results concerning the application of MQMAS spectroscopy, using our simulation programs, to structural study of amorphous materials are presented. The third and last part presents a theoretical and experimental investigation of dipolar order in a rotating sample. Two theoretical models are described, the first for the slow spinning speed regime where an adiabatic approximation can be made, and the second for the fast spinning speed regime. (author)

  7. A proposal for the measurement of Rashba and Dresselhaus spin–orbit interaction strengths in a single sample

    International Nuclear Information System (INIS)

    Maiti, Santanu K.; Sil, Shreekantha; Chakrabarti, Arunava

    2012-01-01

    We establish an exact analytical treatment for the determination of the strengths of the Rashba and Dresselhaus spin–orbit interactions in a single sample by measuring persistent spin current. A hidden symmetry is exploited in the Hamiltonian to show that the spin current vanishes when the strength of the Dresselhaus interaction becomes equal to the strength of the Rashba term. The results are sustained even in the presence of disorder and thus an experiment in this regard will be challenging. -- Highlights: ► An exact analytical treatment is given for the measurement of spin–orbit interaction strengths in a single sample. ► Persistent spin current is calculated. ► Our present analysis gives us confidence to propose an experiment in this line.

  8. Nuclear magnetic resonance studies of quadrupolar nuclei and dipolar field effects

    International Nuclear Information System (INIS)

    Urban, Jeffry Todd

    2004-01-01

    Experimental and theoretical research conducted in two areas in the field of nuclear magnetic resonance (NMR) spectroscopy is presented: (1) studies of the coherent quantum-mechanical control of the angular momentum dynamics of quadrupolar (spin I > 1/2) nuclei and its application to the determination of molecular structure; and (2) applications of the long-range nuclear dipolar field to novel NMR detection methodologies.The dissertation is organized into six chapters. The first two chapters and associated appendices are intended to be pedagogical and include an introduction to the quantum mechanical theory of pulsed NMR spectroscopy and the time dependent theory of quantum mechanics. The third chapter describes investigations of the solid-state multiple-quantum magic angle spinning (MQMAS) NMR experiment applied to I 5/2 quadrupolar nuclei. This work reports the use of rotary resonance-matched radiofrequency irradiation for sensitivity enhancement of the I = 5/2 MQMAS experiment. These experiments exhibited certain selective line narrowing effects which were investigated theoretically.The fourth chapter extends the discussion of multiple quantum spectroscopy of quadrupolar nuclei to a mostly theoretical study of the feasibility of enhancing the resolution of nitrogen-14 NMR of large biomolecules in solution via double-quantum spectroscopy. The fifth chapter continues to extend the principles of multiple quantum NMR spectroscopy of quadrupolar nuclei to make analogies between experiments in NMR/nuclear quadrupolar resonance (NQR) and experiments in atomic/molecular optics (AMO). These analogies are made through the Hamiltonian and density operator formalism of angular momentum dynamics in the presence of electric and magnetic fields.The sixth chapter investigates the use of the macroscopic nuclear dipolar field to encode the NMR spectrum of an analyte nucleus indirectly in the magnetization of a sensor nucleus. This technique could potentially serve as an encoding

  9. Nuclear magnetic resonance studies of quadrupolar nuclei and dipolar field effects

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Jeffry Todd [Univ. of California, Berkeley, CA (United States)

    2004-01-01

    Experimental and theoretical research conducted in two areas in the field of nuclear magnetic resonance (NMR) spectroscopy is presented: (1) studies of the coherent quantum-mechanical control of the angular momentum dynamics of quadrupolar (spin I > 1/2) nuclei and its application to the determination of molecular structure; and (2) applications of the long-range nuclear dipolar field to novel NMR detection methodologies.The dissertation is organized into six chapters. The first two chapters and associated appendices are intended to be pedagogical and include an introduction to the quantum mechanical theory of pulsed NMR spectroscopy and the time dependent theory of quantum mechanics. The third chapter describes investigations of the solid-state multiple-quantum magic angle spinning (MQMAS) NMR experiment applied to I = 5/2 quadrupolar nuclei. This work reports the use of rotary resonance-matched radiofrequency irradiation for sensitivity enhancement of the I = 5/2 MQMAS experiment. These experiments exhibited certain selective line narrowing effects which were investigated theoretically.The fourth chapter extends the discussion of multiple quantum spectroscopy of quadrupolar nuclei to a mostly theoretical study of the feasibility of enhancing the resolution of nitrogen-14 NMR of large biomolecules in solution via double-quantum spectroscopy. The fifth chapter continues to extend the principles of multiple quantum NMR spectroscopy of quadrupolar nuclei to make analogies between experiments in NMR/nuclear quadrupolar resonance (NQR) and experiments in atomic/molecular optics (AMO). These analogies are made through the Hamiltonian and density operator formalism of angular momentum dynamics in the presence of electric and magnetic fields.The sixth chapter investigates the use of the macroscopic nuclear dipolar field to encode the NMR spectrum of an analyte nucleus indirectly in the magnetization of a sensor nucleus. This technique could potentially serve as an

  10. Hybridization quality and bond strength of adhesive systems according to interaction with dentin.

    Science.gov (United States)

    Salvio, Luciana Andrea; Hipólito, Vinicius Di; Martins, Adriano Luis; de Goes, Mario Fernando

    2013-07-01

    To evaluate the hybridization quality and bond strength of adhesives to dentin. Ten human molars were ground to expose the dentin and then sectioned in four tooth-quarters. They were randomly divided into 5 groups according to the adhesive used: Two single-step self-etch adhesives - Adper Prompt (ADP) and Xeno III (XE), two two-step self-etching primer systems - Clearfil SE Bond (SE) and Adhe SE (ADSE), and one one-step etch-and-rinse system - Adper Single Bond (SB). Resin composite (Filtek Z250) crown buildups were made on the bonded surfaces and incrementally light-cured for 20 s. The restored tooth-quarters were stored in water at 37°C for 24 h and then sectioned into beams (0.8 mm(2) in cross-section). Maximal microtensile bond strength (μ-TBS) was recorded (0.5 mm/min in crosshead speed). The results were submitted to one-way ANOVA and Tukey's test (α = 0.05). Thirty additional teeth were used to investigate the hybridization quality by SEM using silver methenamine or ammoniacal silver nitrate dyes. SE reached significantly higher μ-TBS (P 0.05), and between SB and ADP (P > 0.05); ADSE and XE were significantly higher than SB and ADP (P quality than that observed for ADP and XE. The bond strength and hybridization quality were affected by the interaction form of the adhesives with dentin. The hybridization quality was essential to improve the immediate μ-TBS to dentin.

  11. Normal modes and possibility of spatially inhomogeneous phases for a 2D ferromagnet with biquadratic and magnetoelastic interactions

    International Nuclear Information System (INIS)

    Fridman, Yu.A.; Klevets, Ph.N.; Matyunin, D.A.

    2006-01-01

    Influence of the magnetodipolar interaction on the phase states of a 2D non-Heisenberg ferromagnet is investigated. It is shown that in the system considered both the homogeneous states (ferromagnetic or quadrupolar) and the spatially inhomogeneous ones can be realized. At this the spatial inhomogeneity is related with the distribution of the quadrupolar order parameters

  12. Nature and Strength of the Inner-Core H⋅⋅⋅H Interactions in Porphyrinoids.

    Science.gov (United States)

    Singh, Ankit; Sahoo, Dipak Kumar; Sethi, Srikant Kumar; Jena, Subhrakant; Biswal, Himansu S

    2017-12-15

    Several recent publications have illustrated that electrostatic attraction is not solely responsible for strong hydrogen bonds. Even electropositive and less electronegative atoms such as Te and Se are capable of forming strong H-bonds. Herein, we provide evidence for intramolecular homopolar dihydrogen bonds [HOMO-DHBs; X-N(C)-H δ+ ⋅⋅⋅ δ+ H-N(C)-Y] in porphyrins and related compounds for the first time; these bonds are revealed by careful Cambridge Structural Database (CSD) exploration, quantum theory of atoms in molecules, compliance constant calculations, and natural bond orbital and noncovalent interaction (NCI) analysis. A search of the CSD showed that the inner-core hydrogen atom distances were less than 2.5 Å (sum of the van der Waals radii of two hydrogen atoms is 2.4 Å) in porphyrinoids, i.e. about 75 % of the cases. This suggested an attractive interaction between hydrogen atoms carrying a positive charge, which was further supported by quantum-chemical calculations. The HOMO-DHB energy in some cases was found to be as much as around 20 kJ mol -1 , which is comparable to that of any conventional H-bond energy such as for the NH 3 dimer. The interplay between hyperconjugative attraction and steric constraint favorably decided the strength of the HOMO-DHBs. We expect that HOMO-DHBs could be revealed in many more systems, such as corroles, phlorins, crown ethers, and constrained systems having hydrogen atoms in close contact, and could be an important noncovalent interaction to consider in supramolecular chemistry. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Strength of interactions between immobilized dye molecules and sol-gel matrices.

    Science.gov (United States)

    Ismail, Fanya; Schoenleber, Monika; Mansour, Rolan; Bastani, Behnam; Fielden, Peter; Goddard, Nicholas J

    2011-02-21

    In this paper we present a new theory to re-examine the immobilization technique of dye doped sol-gel films, define the strength and types of possible bonds between the immobilized molecule and sol-gel glass, and show that the immobilized molecule is not free inside the pores as was previously thought. Immobilizing three different pH sensitive dyes with different size and functional groups inside the same sol-gel films revealed important information about the nature of the interaction between the doped molecule and the sol-gel matrix. The samples were characterized by means of ultraviolet-visible spectrophotometer (UV-VIS), thermal gravimetric analysis (TGA), mercury porosimetry (MP), nuclear magnetic resonance spectroscopy ((29)Si NMR) and field-emission environmental scanning electron microscopy (ESEM-FEG). It was found that the doped molecule itself has a great effect on the strength and types of the bonds. A number of factors were identified, such as number and types of the functional groups, overall charge, size, pK(a) and number of the silanol groups which surround the immobilized molecule. These results were confirmed by the successful immobilization of bromocresol green (BCG) after a completely polymerized sol-gel was made. The sol-gel consisted of 50% tetraethoxysilane (TEOS) and 50% methyltriethoxysilane (MTEOS) (w/w). Moreover, the effect of the immobilized molecule on the structure of the sol-gel was studied by means of a leaky waveguide (LW) mode for doped films made before and after polymerization of the sol-gel.

  14. On Thermally Interacting Multiple Boreholes with Variable Heating Strength: Comparison between Analytical and Numerical Approaches

    Directory of Open Access Journals (Sweden)

    Marc A. Rosen

    2012-08-01

    Full Text Available The temperature response in the soil surrounding multiple boreholes is evaluated analytically and numerically. The assumption of constant heat flux along the borehole wall is examined by coupling the problem to the heat transfer problem inside the borehole and presenting a model with variable heat flux along the borehole length. In the analytical approach, a line source of heat with a finite length is used to model the conduction of heat in the soil surrounding the boreholes. In the numerical method, a finite volume method in a three dimensional meshed domain is used. In order to determine the heat flux boundary condition, the analytical quasi-three-dimensional solution to the heat transfer problem of the U-tube configuration inside the borehole is used. This solution takes into account the variation in heating strength along the borehole length due to the temperature variation of the fluid running in the U-tube. Thus, critical depths at which thermal interaction occurs can be determined. Finally, in order to examine the validity of the numerical method, a comparison is made with the results of line source method.

  15. Control of the interaction strength of photonic molecules by nanometer precise 3D fabrication.

    Science.gov (United States)

    Rawlings, Colin D; Zientek, Michal; Spieser, Martin; Urbonas, Darius; Stöferle, Thilo; Mahrt, Rainer F; Lisunova, Yuliya; Brugger, Juergen; Duerig, Urs; Knoll, Armin W

    2017-11-28

    Applications for high resolution 3D profiles, so-called grayscale lithography, exist in diverse fields such as optics, nanofluidics and tribology. All of them require the fabrication of patterns with reliable absolute patterning depth independent of the substrate location and target materials. Here we present a complete patterning and pattern-transfer solution based on thermal scanning probe lithography (t-SPL) and dry etching. We demonstrate the fabrication of 3D profiles in silicon and silicon oxide with nanometer scale accuracy of absolute depth levels. An accuracy of less than 1nm standard deviation in t-SPL is achieved by providing an accurate physical model of the writing process to a model-based implementation of a closed-loop lithography process. For transfering the pattern to a target substrate we optimized the etch process and demonstrate linear amplification of grayscale patterns into silicon and silicon oxide with amplification ratios of ∼6 and ∼1, respectively. The performance of the entire process is demonstrated by manufacturing photonic molecules of desired interaction strength. Excellent agreement of fabricated and simulated structures has been achieved.

  16. Group theory for magnetic structure determination: Recent developments and quadrupolar ordering analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sikora, W. [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, al.Mickiewicza 30, 30-059 Cracow (Poland)]. E-mail: sikora@novell.ftj.agh.edu.pl; Pytlik, L. [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, al.Mickiewicza 30, 30-059 Cracow (Poland); Bialas, F. [Nowy Sacz School of Busines-National Louis University, 33-300 Nowy Sacz (Poland); Malinowski, J. [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, al.Mickiewicza 30, 30-059 Cracow (Poland)

    2007-09-13

    In this paper, the recent developments in practical applications of symmetry analysis are described. The theoretical basis shortly described in Section 1 has been implemented in several computer applications, one of which is the program 'MODY-win', developed by the authors of the paper. The program calculates the so-called basis vectors of irreducible representations of a given symmetry group, which can be used for calculation of possible ordering modes. Its practical application is demonstrated on some examples, presenting the recent aspects of using the symmetry analysis to description of various types of ordering encountered in solids. The scalar-type ordering (occupation probability) is discussed shortly for occupation of interstitial sites by hydrogen atoms in inter-metallic compounds. The description of vector ordering is demonstrated on the magnetic ordering modes, with special attention focused on the freedom that is left in the structure after imposing all the symmetry constraints. In practice, the final ordering mode usually contains some free parameters that cannot be determined from the symmetry itself. The last application presented in the paper is the description of quadrupolar ordering, recently found in some compounds of 4f (5f) elements. For the latter case, an additional advantage is demonstrated by calculation of possible displacements of neighboring atoms after the establishment of non-zero quadrupolar order parameter on the central atom.

  17. Quadrupolar frustration in shastry-sutherland lattice of DyB4 studied by resonant x-ray scattering

    International Nuclear Information System (INIS)

    Okuyama, Daisuke; Matsumura, Takeshi; Nakao, Hironori; Murakami, Youichi

    2005-01-01

    We have observed geometrical frustration of quadrupolar and magnetic moments in dysprosium tetraboride, DyB 4 , where the rare-earth sites form a Shastry-Sutherland lattice. Resonant X-ray scattering at the L III absorption edge of Dy was utilized. Analysis of the energy, polarization, temperature, and azimuthal-angle dependences of the E1 resonance of the (100) forbidden reflection show that the magnetic and quadrupolar components within the frustrated c plane have a short-range correlation, suggesting that the moments are fluctuating. In contrast, the basic antiferromagnetic component along the c-axis has a long-range order. (author)

  18. Saturated fat consumption and the Theory of Planned Behaviour: exploring additive and interactive effects of habit strength

    NARCIS (Netherlands)

    de Bruijn, G.J.; Kroeze, W.; Oenema, O.; Brug, J.

    2008-01-01

    The additive and interactive effects of habit strength in the explanation of saturated fat intake were explored within the framework of the Theory of Planned Behaviour (TPB). Cross-sectional data were gathered in a Dutch adult sample (n = 764) using self-administered questionnaires and analyzed

  19. Preventive Strength of Dyadic Social Interaction against Reacquisition/Reexpression of Cocaine Conditioned Place Preference.

    Science.gov (United States)

    Bregolin, Tanja; Pinheiro, Barbara S; El Rawas, Rana; Zernig, Gerald

    2017-01-01

    The reorientation away from drugs of abuse and toward social interaction is a highly desirable but as yet elusive goal in the therapy of substance dependence. We could previously show that cocaine preferring Sprague-Dawley rats which engaged in only four 15 min episodes of dyadic social interaction (DSI) did not reacquire and reexpress cocaine conditioned place preference (CPP) after a single cocaine exposure. In the present study, we investigated how strong this preventive effect of DSI is. In corroboration of our previous findings in rats, four 15 min DSI episodes prevented the reacquisition/reexpression of cocaine CPP in mice. However, this effect was only observed if only one cocaine conditioning session (15 min) was used. If mice were counterconditioned with a total of four cocaine sessions, the cocaine CPP reemerged. Interestingly, the opposite also held true: in mice that had acquired/expressed cocaine CPP, one conditioning session with DSI did not prevent the persistence of cocaine CPP, whereas four DSI conditioning sessions reversed CPP for 15 mg/kg intraperitoneal cocaine. Of note, this cocaine dose was a strong reward in C57BL/6J mice, causing CPP in all tested animals. Our findings suggest that both the reversal (reconditioning) of CPP from cocaine to DSI as well as that from DSI to cocaine requires four conditioning sessions. As previously shown in C57BL/6 mice from the NIH substrain, mice from the Jackson substrain also showed a greater relative preference for 15 mg/kg intraperitoneal cocaine over DSI, whereas Sprague-Dawley rats were equally attracted to contextual stimuli associated with this cocaine dose and DSI. Also in corroboration of previous findings, both C57BL/6J mice and experimenters several generations removed from the original ones produced CPP for DSI to a lesser degree than Sprague-Dawley rats. Our findings demonstrate the robustness of our experimental model across several subject- and experimenter generations in two rodent genus (i

  20. Preventive Strength of Dyadic Social Interaction against Reacquisition/Reexpression of Cocaine Conditioned Place Preference

    Directory of Open Access Journals (Sweden)

    Tanja Bregolin

    2017-11-01

    Full Text Available The reorientation away from drugs of abuse and toward social interaction is a highly desirable but as yet elusive goal in the therapy of substance dependence. We could previously show that cocaine preferring Sprague-Dawley rats which engaged in only four 15 min episodes of dyadic social interaction (DSI did not reacquire and reexpress cocaine conditioned place preference (CPP after a single cocaine exposure. In the present study, we investigated how strong this preventive effect of DSI is. In corroboration of our previous findings in rats, four 15 min DSI episodes prevented the reacquisition/reexpression of cocaine CPP in mice. However, this effect was only observed if only one cocaine conditioning session (15 min was used. If mice were counterconditioned with a total of four cocaine sessions, the cocaine CPP reemerged. Interestingly, the opposite also held true: in mice that had acquired/expressed cocaine CPP, one conditioning session with DSI did not prevent the persistence of cocaine CPP, whereas four DSI conditioning sessions reversed CPP for 15 mg/kg intraperitoneal cocaine. Of note, this cocaine dose was a strong reward in C57BL/6J mice, causing CPP in all tested animals. Our findings suggest that both the reversal (reconditioning of CPP from cocaine to DSI as well as that from DSI to cocaine requires four conditioning sessions. As previously shown in C57BL/6 mice from the NIH substrain, mice from the Jackson substrain also showed a greater relative preference for 15 mg/kg intraperitoneal cocaine over DSI, whereas Sprague-Dawley rats were equally attracted to contextual stimuli associated with this cocaine dose and DSI. Also in corroboration of previous findings, both C57BL/6J mice and experimenters several generations removed from the original ones produced CPP for DSI to a lesser degree than Sprague-Dawley rats. Our findings demonstrate the robustness of our experimental model across several subject- and experimenter generations in two

  1. Δ effects in pion-nucleon scattering and the strength of the two-pion-exchange three-nucleon interaction

    International Nuclear Information System (INIS)

    Pandharipande, V.R.; Phillips, D.R.; Kolck, U. van

    2005-01-01

    We consider the relationship between p-wave πN scattering and the strength of the p-wave two-pion-exchange three-nucleon interaction (TPE3NI). We explain why effective theories that do not contain the Delta resonance as an explicit degree of freedom tend to overestimate the strength of the TPE3NI. The overestimation can be remedied by higher-order terms in these 'Delta-less' theories, but such terms are not yet included in state-of-the-art chiral effective field theory calculations of the nuclear force. This suggests that these calculations can predict the strength of the TPE3NI only to an accuracy of ±25%

  2. Bis-pyridinium quadrupolar derivatives. High Stokes shift selective probes for bio-imaging

    Science.gov (United States)

    Salice, Patrizio; Versari, Silvia; Bradamante, Silvia; Meinardi, Francesco; Macchi, Giorgio; Pagani, Giorgio A.; Beverina, Luca

    2013-11-01

    We describe the design, synthesis and characterization of five high Stokes shift quadrupolar heteroaryl compounds suitable as fluorescent probes in bio-imaging. In particular, we characterize the photophysical properties and the intracellular localization in Human Umbilical Vein Endothelial Cells (HUVEC) and Human Mesenchymal Stem Cells (HMSCs) for each dye. We show that, amongst all of the investigated derivatives, the 2,5-bis[1-(4-N-methylpyridinium)ethen-2-yl)]- N-methylpyrrole salt is the best candidates as selective mitochondrial tracker. Finally, we recorded the full emission spectrum of the most performing - exclusively mitochondrial selective - fluorescent probe directly from HUVEC stained cells. The emission spectrum collected from the stained mitochondria shows a remarkably more pronounced vibronic structure with respect to the emission of the free fluorophore in solution.

  3. Retrospective Attention Interacts with Stimulus Strength to Shape Working Memory Performance.

    Science.gov (United States)

    Wildegger, Theresa; Humphreys, Glyn; Nobre, Anna C

    2016-01-01

    Orienting attention retrospectively to selective contents in working memory (WM) influences performance. A separate line of research has shown that stimulus strength shapes perceptual representations. There is little research on how stimulus strength during encoding shapes WM performance, and how effects of retrospective orienting might vary with changes in stimulus strength. We explore these questions in three experiments using a continuous-recall WM task. In Experiment 1 we show that benefits of cueing spatial attention retrospectively during WM maintenance (retrocueing) varies according to stimulus contrast during encoding. Retrocueing effects emerge for supraliminal but not sub-threshold stimuli. However, once stimuli are supraliminal, performance is no longer influenced by stimulus contrast. In Experiments 2 and 3 we used a mixture-model approach to examine how different sources of error in WM are affected by contrast and retrocueing. For high-contrast stimuli (Experiment 2), retrocues increased the precision of successfully remembered items. For low-contrast stimuli (Experiment 3), retrocues decreased the probability of mistaking a target with distracters. These results suggest that the processes by which retrospective attentional orienting shape WM performance are dependent on the quality of WM representations, which in turn depends on stimulus strength during encoding.

  4. Retrospective Attention Interacts with Stimulus Strength to Shape Working Memory Performance.

    Directory of Open Access Journals (Sweden)

    Theresa Wildegger

    Full Text Available Orienting attention retrospectively to selective contents in working memory (WM influences performance. A separate line of research has shown that stimulus strength shapes perceptual representations. There is little research on how stimulus strength during encoding shapes WM performance, and how effects of retrospective orienting might vary with changes in stimulus strength. We explore these questions in three experiments using a continuous-recall WM task. In Experiment 1 we show that benefits of cueing spatial attention retrospectively during WM maintenance (retrocueing varies according to stimulus contrast during encoding. Retrocueing effects emerge for supraliminal but not sub-threshold stimuli. However, once stimuli are supraliminal, performance is no longer influenced by stimulus contrast. In Experiments 2 and 3 we used a mixture-model approach to examine how different sources of error in WM are affected by contrast and retrocueing. For high-contrast stimuli (Experiment 2, retrocues increased the precision of successfully remembered items. For low-contrast stimuli (Experiment 3, retrocues decreased the probability of mistaking a target with distracters. These results suggest that the processes by which retrospective attentional orienting shape WM performance are dependent on the quality of WM representations, which in turn depends on stimulus strength during encoding.

  5. Characterization of Final State Interaction Strength in Plastic Scintillator by Muon-Neutrino Charged Current Charged Pion Production

    Energy Technology Data Exchange (ETDEWEB)

    Eberly, Brandon M. [Univ. of Pittsburgh, PA (United States)

    2014-01-01

    Precise knowledge of neutrino-nucleus interactions is increasingly important as neutrino oscillation measurements transition into the systematics-limited era. In addition to modifying the initial interaction, the nuclear medium can scatter and absorb the interaction by-products through final state interactions, changing the types and kinematic distributions of particles seen by the detector. Recent neutrino pion production data from MiniBooNE is inconsistent with the final state interaction strength predicted by models and theoretical calculations, and some models fit best to the MiniBooNE data only after removing final state interactions entirely. This thesis presents a measurement of dσ/dTπ and dσ/dθπ for muon-neutrino charged current charged pion production in the MINER A scintillator tracker. MINER A is a neutrino-nucleus scattering experiment installed in the few-GeV NuMI beam line at Fermilab. The analysis is limited to neutrino energies between 1.5-10 GeV. Dependence on invariant hadronic mass W is studied through two versions of the analysis that impose the limits W < 1.4 GeV and W < 1.8 GeV. The lower limit on W increases compatibility with the MiniBooNE pion data. The shapes of the differential cross sections, which depend strongly on the nature of final state interactions, are compared to Monte Carlo and theoretical predictions. It is shown that the measurements presented in this thesis favor models that contain final state interactions. Additionally, a variety of neutrino-nucleus interaction models are shown to successfully reproduce the thesis measurements, while simultaneously failing to describe the shape of the MiniBooNE data.

  6. Effective oscillator strength distributions of spherically symmetric atoms for calculating polarizabilities and long-range atom–atom interactions

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Jun, E-mail: phyjiang@yeah.net [Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); School of Engineering, Charles Darwin University, Darwin, Northern Territory, 0909 (Australia); Mitroy, J. [School of Engineering, Charles Darwin University, Darwin, Northern Territory, 0909 (Australia); Cheng, Yongjun, E-mail: cyj83mail@gmail.com [School of Engineering, Charles Darwin University, Darwin, Northern Territory, 0909 (Australia); Academy of Fundamental and Interdisciplinary Science, Harbin Institute of Technology, Harbin 150080 (China); Bromley, M.W.J., E-mail: brom@physics.uq.edu.au [School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland 4075 (Australia)

    2015-01-15

    Effective oscillator strength distributions are systematically generated and tabulated for the alkali atoms, the alkaline-earth atoms, the alkaline-earth ions, the rare gases and some miscellaneous atoms. These effective distributions are used to compute the dipole, quadrupole and octupole static polarizabilities, and are then applied to the calculation of the dynamic polarizabilities at imaginary frequencies. These polarizabilities can be used to determine the long-range C{sub 6}, C{sub 8} and C{sub 10} atom–atom interactions for the dimers formed from any of these atoms and ions, and we present tables covering all of these combinations.

  7. Effective oscillator strength distributions of spherically symmetric atoms for calculating polarizabilities and long-range atom–atom interactions

    International Nuclear Information System (INIS)

    Jiang, Jun; Mitroy, J.; Cheng, Yongjun; Bromley, M.W.J.

    2015-01-01

    Effective oscillator strength distributions are systematically generated and tabulated for the alkali atoms, the alkaline-earth atoms, the alkaline-earth ions, the rare gases and some miscellaneous atoms. These effective distributions are used to compute the dipole, quadrupole and octupole static polarizabilities, and are then applied to the calculation of the dynamic polarizabilities at imaginary frequencies. These polarizabilities can be used to determine the long-range C 6 , C 8 and C 10 atom–atom interactions for the dimers formed from any of these atoms and ions, and we present tables covering all of these combinations

  8. Hybridization quality and bond strength of adhesive systems according to interaction with dentin

    Science.gov (United States)

    Salvio, Luciana Andrea; Hipólito, Vinicius Di; Martins, Adriano Luis; de Goes, Mario Fernando

    2013-01-01

    Objective: To evaluate the hybridization quality and bond strength of adhesives to dentin. Materials and Methods: Ten human molars were ground to expose the dentin and then sectioned in four tooth-quarters. They were randomly divided into 5 groups according to the adhesive used: Two single-step self-etch adhesives – Adper Prompt (ADP) and Xeno III (XE), two two-step self-etching primer systems – Clearfil SE Bond (SE) and Adhe SE (ADSE), and one one-step etch-and-rinse system – Adper Single Bond (SB). Resin composite (Filtek Z250) crown buildups were made on the bonded surfaces and incrementally light-cured for 20 s. The restored tooth-quarters were stored in water at 37°C for 24 h and then sectioned into beams (0.8 mm2 in cross-section). Maximal microtensile bond strength (μ-TBS) was recorded (0.5 mm/min in crosshead speed). The results were submitted to one-way ANOVA and Tukey's test (α = 0.05). Thirty additional teeth were used to investigate the hybridization quality by SEM using silver methenamine or ammoniacal silver nitrate dyes. Results: SE reached significantly higher μ-TBS (P 0.05), and between SB and ADP (P > 0.05); ADSE and XE were significantly higher than SB and ADP (P adhesives with dentin. The hybridization quality was essential to improve the immediate μ-TBS to dentin. PMID:24926212

  9. BRICTEST: a code for charge breeding simulations in RF quadrupolar field

    International Nuclear Information System (INIS)

    Variale, V.; Claudione, M.

    2005-01-01

    In the framework of the SPES project (Study for Production of Exotic Species), funded by Istituto Nazionale Fisica Nucleare (INFN) at the Laboratori Nazionali Legnaro (LNL) (Padua) for Radioactive Ion Beam (RIB) production, an R and D experiment of a charge breeder device, called BRIC (BReeding Ion Charge), is in progress at LNL. BRIC is an Electron Beam Ion Source (EBIS) type ion charge state breeder in which a radio frequency (RF) quadrupolar field has been superimposed in the trapped ion region to introduce a selective containment with the aim of increasing the wanted ion trapping efficiency. A code that studies the motion and the ion charge state evolution in the trap region of the BRIC device has been recently developed in the Bari INFN section. That code has the aim of showing if, in the presence of an axial magnetic field and electron beam space charge force, the RF quadrupole field can still give a selective ion containment in the EBIS trap region. The code, furthermore, should allow choosing the RF quadrupole parameters to optimize the ion charge containment efficiency. In this paper the main feature of the code, named BRICTEST, and the simulation test will be presented and shortly discussed

  10. Strength of tensor force and s-d-shell effective interactions

    International Nuclear Information System (INIS)

    Jiang, M.; Machleidt, R.; Stout, D.B.; Kuo, T.T.S.

    1989-01-01

    The s-d-shell effective interaction is derived from the Bonn NN potential, using a G-matrix folded-diagram method. It is found that due to the relatively weak-tensor-force characteristic for the Bonn potential, the effective interaction matrix elements, particularly those with isospin T=0, come out generally more attractive than in previous derivations which were based on conventional local strong-tensor-force NN potentials. This renders the results obtained with the Bonn potential in considerably better agreement with the recent s-d-shell matrix elements of Wildenthal

  11. Modeling Cable and Guide Channel Interaction in a High-Strength Cable-Driven Continuum Manipulator.

    Science.gov (United States)

    Moses, Matthew S; Murphy, Ryan J; Kutzer, Michael D M; Armand, Mehran

    2015-12-01

    This paper presents several mechanical models of a high-strength cable-driven dexterous manipulator designed for surgical procedures. A stiffness model is presented that distinguishes between contributions from the cables and the backbone. A physics-based model incorporating cable friction is developed and its predictions are compared with experimental data. The data show that under high tension and high curvature, the shape of the manipulator deviates significantly from a circular arc. However, simple parametric models can fit the shape with good accuracy. The motivating application for this study is to develop a model so that shape can be predicted using easily measured quantities such as tension, so that real-time navigation may be performed, especially in minimally-invasive surgical procedures, while reducing the need for hazardous imaging methods such as fluoroscopy.

  12. Influence of pressure and interactions strength on hysteretic behavior in two-dimensional polymeric spin crossover compounds

    Energy Technology Data Exchange (ETDEWEB)

    Chiruta, Daniel [GEMAC, Université de Versailles Saint-Quentin-en-Yvelines, CNRS-UVSQ (UMR 8635), 78035 Versailles Cedex (France); LISV, Université de Versailles Saint-Quentin-en-Yvelines, 78140 Velizy (France); Faculty of Electrical Engineering and Computer Science, Stefan cel Mare University, 720229 Suceava (Romania); Linares, Jorge [GEMAC, Université de Versailles Saint-Quentin-en-Yvelines, CNRS-UVSQ (UMR 8635), 78035 Versailles Cedex (France); Richard Dahoo, Pierre [LATMOS, Université de Versailles-Saint-Quentin-en-Yvelines, CNRS-UPMC-UVSQ (UMR 8190), 78280 Guyancourt (France); Dimian, Mihai, E-mail: dimian@usv.ro [Faculty of Electrical Engineering and Computer Science, Stefan cel Mare University, 720229 Suceava (Romania)

    2014-02-15

    A study of thermal behavior for two-dimensional spin-crossover compounds is performed by using an Ising-like model including both short-range and long-range interactions and a Monte Carlo entropic sampling technique for determining the associated density of states. The effects of various factors, such as external pressure, internal interaction strength or system size, on the thermal transition are analyzed and compared to several experimental findings in this area. The study is focused on two-step transitions and the conditions for hysteresis behavior at each step which are especially important for the potential applications of spin-crossover materials in data storage devices or smart sensors.

  13. Single nuclear transfer strengths and sum rules in the interacting boson-fermion model and in the spectral averaging theory

    International Nuclear Information System (INIS)

    Kota, V.K.B.

    1991-01-01

    In the interacting boson-fermion model of collective nuclei, in the symmetry limits of the model appropriate for vibrational, rotational and γ-unstable nuclei, for one-particle transfer, the selection rules, model predictions for the allowed strengths and comparison of theory with experiment are briefly reviewed. In the spectral-averaging theory, with the specific example of orbit occupancies, the smoothed forms (linear or better ratio of Gaussians) as determined by central limit theorems, how they provide a good criterion for selecting effective interactions and the convolution structure of occupancy densities in huge spaces are described. Complementary information provided by nuclear models and statistical laws is broughtout. (author). 63 refs., 5 figs

  14. Rice Starch Particle Interactions at Air/Aqueous Interfaces—Effect of Particle Hydrophobicity and Solution Ionic Strength

    Science.gov (United States)

    McNamee, Cathy E.; Sato, Yu; Wiege, Berthold; Furikado, Ippei; Marefati, Ali; Nylander, Tommy; Kappl, Michael; Rayner, Marilyn

    2018-01-01

    Starch particles modified by esterification with dicarboxylic acids to give octenyl succinic anhydride (OSA) starch is an approved food additive that can be used to stabilize oil in water emulsions used in foods and drinks. However, the effects of the OSA modification of the starch particle on the interfacial interactions are not fully understood. Here, we directly measured the packing of films of rice starch granules, i.e., the natural particle found inside the plant, at air/aqueous interfaces, and the interaction forces in that system as a function of the particle hydrophobicity and ionic strength, in order to gain insight on how starch particles can stabilize emulsions. This was achieved by using a combined Langmuir trough and optical microscope system, and the Monolayer Interaction Particle Apparatus. Native rice starch particles were seen to form large aggregates at air/water interfaces, causing films with large voids to be formed at the interface. The OSA modification of the rice starches particles decreased this aggregation. Increasing the degree of modification improved the particle packing within the film of particles at the air/water interface, due to the introduction of inter-particle electrostatic interactions within the film. The introduction of salt to the water phase caused the particles to aggregate and form holes within the film, due to the screening of the charged groups on the starch particles by the salt. The presence of these holes in the film decreased the stiffness of the films. The effect of the OSA modification was concluded to decrease the aggregation of the particles at an air/water interface. The presence of salts, however, caused the particles to aggregate, thereby reducing the strength of the interfacial film. PMID:29868551

  15. Soil inoculation method determines the strength of plant-soil interactions

    NARCIS (Netherlands)

    Voorde, van de T.F.J.; Ruijten, M.; Putten, van der W.H.; Bezemer, T.M.

    2012-01-01

    There is increasing evidence that interactions between plants and biotic components of the soil influence plant productivity and plant community composition. Many plant–soil feedback experiments start from inoculating relatively small amounts of natural soil to sterilized bulk soil. These soil

  16. Particle-in-cell simulations of asymmetric guide-field reconnection: quadrupolar structure of Hall magnetic field

    Science.gov (United States)

    Schmitz, R. G.; Alves, M. V.; Barbosa, M. V. G.

    2017-12-01

    One of the most important processes that occurs in Earth's magnetosphere is known as magnetic reconnection (MR). This process can be symmetric or asymmetric, depending basically on the plasma density and magnetic field in both sides of the current sheet. A good example of symmetric reconnection in terrestrial magnetosphere occurs in the magnetotail, where these quantities are similar on the north and south lobes. In the dayside magnetopause MR is asymmetric, since the plasma regimes and magnetic fields of magnetosheath and magnetosphere are quite different. Symmetric reconnection has some unique signatures. For example, the formation of a quadrupolar structure of Hall magnetic field and a bipolar Hall electric field that points to the center of the current sheet. The different particle motions in the presence of asymmetries change these signatures, causing the quadrupolar pattern to be distorted and forming a bipolar structure. Also, the bipolar Hall electric field is modified and gives rise to a single peak pointing toward the magnetosheat, considering an example of magnetopause reconnection. The presence of a guide-field can also distort the quadrupolar pattern, by giving a shear angle across the current sheet and altering the symmetric patterns, according to previous simulations and observations. Recently, a quadrupolar structure was observed in an asymmetric guide-field MR event using MMS (Magnetospheric Multiscale) mission data [Peng et al., JGR, 2017]. This event shows clearly that the density asymmetry and the guide-field were not sufficient to form signatures of asymmetric reconnection. Using the particle-in-cell code iPIC3D [Markidis et al, Mathematics and Computers in Simulation, 2010] with the MMS data from this event used to define input parameters, we found a quadrupolar structure of Hall magnetic field and a bipolar pattern of Hall electric field in ion scales, showing that our results are in an excellent agreement with the MMS observations. To our

  17. Assessment of interaction-strength interpolation formulas for gold and silver clusters

    Science.gov (United States)

    Giarrusso, Sara; Gori-Giorgi, Paola; Della Sala, Fabio; Fabiano, Eduardo

    2018-04-01

    The performance of functionals based on the idea of interpolating between the weak- and the strong-interaction limits the global adiabatic-connection integrand is carefully studied for the challenging case of noble-metal clusters. Different interpolation formulas are considered and various features of this approach are analyzed. It is found that these functionals, when used as a correlation correction to Hartree-Fock, are quite robust for the description of atomization energies, while performing less well for ionization potentials. Future directions that can be envisaged from this study and a previous one on main group chemistry are discussed.

  18. Connection Between Thermodynamics and Dynamics of Simple Fluids in Pores: Impact of Fluid-Fluid Interaction Range and Fluid-Solid Interaction Strength.

    Science.gov (United States)

    Krekelberg, William P; Siderius, Daniel W; Shen, Vincent K; Truskett, Thomas M; Errington, Jeffrey R

    2017-08-03

    Using molecular simulations, we investigate how the range of fluid-fluid (adsorbate-adsorbate) interactions and the strength of fluid-solid (adsorbate-adsorbent) interactions impact the strong connection between distinct adsorptive regimes and distinct self-diffusivity regimes reported in [Krekelberg, W. P.; Siderius, D. W.; Shen, V. K.; Truskett, T. M.; Errington, J. R. Langmuir 2013 , 29 , 14527-14535]. Although increasing the fluid-fluid interaction range changes both the thermodynamics and the dynamic properties of adsorbed fluids, the previously reported connection between adsorptive filling regimes and self-diffusivity regimes remains. Increasing the fluid-fluid interaction range leads to enhanced layering and decreased self-diffusivity in the multilayer-formation regime but has little effect on the properties within film-formation and pore-filling regimes. We also find that weakly attractive adsorbents, which do not display distinct multilayer formation, are hard-sphere-like at super- and subcritical temperatures. In this case, the self-diffusivity of the confined and bulk fluid has a nearly identical scaling-relationship with effective density.

  19. On the microscopic fluctuations driving the NMR relaxation of quadrupolar ions in water

    Energy Technology Data Exchange (ETDEWEB)

    Carof, Antoine; Salanne, Mathieu; Rotenberg, Benjamin, E-mail: benjamin.rotenberg@upmc.fr [Sorbonne Universités, UPMC Univ. Paris 06, CNRS, Laboratoire PHENIX, Case 51, 4 Place Jussieu, F-75005 Paris (France); Charpentier, Thibault [CEA, IRAMIS, NIMBE, LSDRM, UMR CEA-CNRS 3685, F-91191 Gif-sur-Yvette Cedex (France)

    2015-11-21

    Nuclear Magnetic Resonance (NMR) relaxation is sensitive to the local structure and dynamics around the probed nuclei. The Electric Field Gradient (EFG) is the key microscopic quantity to understand the NMR relaxation of quadrupolar ions, such as {sup 7}Li{sup +}, {sup 23}Na{sup +}, {sup 25}Mg{sup 2+}, {sup 35}Cl{sup −}, {sup 39}K{sup +}, or {sup 133}Cs{sup +}. Using molecular dynamics simulations, we investigate the statistical and dynamical properties of the EFG experienced by alkaline, alkaline Earth, and chloride ions at infinite dilution in water. Specifically, we analyze the effect of the ionic charge and size on the distribution of the EFG tensor and on the multi-step decay of its auto-correlation function. The main contribution to the NMR relaxation time arises from the slowest mode, with a characteristic time on the picosecond time scale. The first solvation shell of the ion plays a dominant role in the fluctuations of the EFG, all the more that the ion radius is small and its charge is large. We propose an analysis based on a simplified charge distribution around the ion, which demonstrates that the auto-correlation of the EFG, hence the NMR relaxation time, reflects primarily the collective translational motion of water molecules in the first solvation shell of the cations. Our findings provide a microscopic route to the quantitative interpretation of NMR relaxation measurements and open the way to the design of improved analytical theories for NMR relaxation for small ionic solutes, which should focus on water density fluctuations around the ion.

  20. The Effect of Combined Magnetic Geometries on Thermally Driven Winds. II. Dipolar, Quadrupolar, and Octupolar Topologies

    Science.gov (United States)

    Finley, Adam J.; Matt, Sean P.

    2018-02-01

    During the lifetime of Sun-like or low-mass stars a significant amount of angular momentum is removed through magnetized stellar winds. This process is often assumed to be governed by the dipolar component of the magnetic field. However, observed magnetic fields can host strong quadrupolar and/or octupolar components, which may influence the resulting spin-down torque on the star. In Paper I, we used the MHD code PLUTO to compute steady-state solutions for stellar winds containing a mixture of dipole and quadrupole geometries. We showed the combined winds to be more complex than a simple sum of winds with these individual components. This work follows the same method as Paper I, including the octupole geometry, which not only increases the field complexity but also, more fundamentally, looks for the first time at combining the same symmetry family of fields, with the field polarity of the dipole and octupole geometries reversing over the equator (unlike the symmetric quadrupole). We show, as in Paper I, that the lowest-order component typically dominates the spin-down torque. Specifically, the dipole component is the most significant in governing the spin-down torque for mixed geometries and under most conditions for real stars. We present a general torque formulation that includes the effects of complex, mixed fields, which predicts the torque for all the simulations to within 20% precision, and the majority to within ≈5%. This can be used as an input for rotational evolution calculations in cases where the individual magnetic components are known.

  1. Monodisperse measurement of the biotin-streptavidin interaction strength in a well-defined pulling geometry.

    Directory of Open Access Journals (Sweden)

    Steffen M Sedlak

    Full Text Available The widely used interaction of the homotetramer streptavidin with the small molecule biotin has been intensively studied by force spectroscopy and has become a model system for receptor ligand interaction. However, streptavidin's tetravalency results in diverse force propagation pathways through the different binding interfaces. This multiplicity gives rise to polydisperse force spectroscopy data. Here, we present an engineered monovalent streptavidin tetramer with a single cysteine in its functional subunit that allows for site-specific immobilization of the molecule, orthogonal to biotin binding. Functionality of streptavidin and its binding properties for biotin remain unaffected. We thus created a stable and reliable molecular anchor with a unique high-affinity binding site for biotinylated molecules or nanoparticles, which we expect to be useful for many single-molecule applications. To characterize the mechanical properties of the bond between biotin and our monovalent streptavidin, we performed force spectroscopy experiments using an atomic force microscope. We were able to conduct measurements at the single-molecule level with 1:1-stoichiometry and a well-defined geometry, in which force exclusively propagates through a single subunit of the streptavidin tetramer. For different force loading rates, we obtained narrow force distributions of the bond rupture forces ranging from 200 pN at 1,500 pN/s to 230 pN at 110,000 pN/s. The data are in very good agreement with the standard Bell-Evans model with a single potential barrier at Δx0 = 0.38 nm and a zero-force off-rate koff,0 in the 10-6 s-1 range.

  2. Monodisperse measurement of the biotin-streptavidin interaction strength in a well-defined pulling geometry.

    Science.gov (United States)

    Sedlak, Steffen M; Bauer, Magnus S; Kluger, Carleen; Schendel, Leonard C; Milles, Lukas F; Pippig, Diana A; Gaub, Hermann E

    2017-01-01

    The widely used interaction of the homotetramer streptavidin with the small molecule biotin has been intensively studied by force spectroscopy and has become a model system for receptor ligand interaction. However, streptavidin's tetravalency results in diverse force propagation pathways through the different binding interfaces. This multiplicity gives rise to polydisperse force spectroscopy data. Here, we present an engineered monovalent streptavidin tetramer with a single cysteine in its functional subunit that allows for site-specific immobilization of the molecule, orthogonal to biotin binding. Functionality of streptavidin and its binding properties for biotin remain unaffected. We thus created a stable and reliable molecular anchor with a unique high-affinity binding site for biotinylated molecules or nanoparticles, which we expect to be useful for many single-molecule applications. To characterize the mechanical properties of the bond between biotin and our monovalent streptavidin, we performed force spectroscopy experiments using an atomic force microscope. We were able to conduct measurements at the single-molecule level with 1:1-stoichiometry and a well-defined geometry, in which force exclusively propagates through a single subunit of the streptavidin tetramer. For different force loading rates, we obtained narrow force distributions of the bond rupture forces ranging from 200 pN at 1,500 pN/s to 230 pN at 110,000 pN/s. The data are in very good agreement with the standard Bell-Evans model with a single potential barrier at Δx0 = 0.38 nm and a zero-force off-rate koff,0 in the 10-6 s-1 range.

  3. Foraging modality and plasticity in foraging traits determine the strength of competitive interactions among carnivorous plants, spiders and toads.

    Science.gov (United States)

    Jennings, David E; Krupa, James J; Rohr, Jason R

    2016-07-01

    Foraging modalities (e.g. passive, sit-and-wait, active) and traits are plastic in some species, but the extent to which this plasticity affects interspecific competition remains unclear. Using a long-term laboratory mesocosm experiment, we quantified competition strength and the plasticity of foraging traits in a guild of generalist predators of arthropods with a range of foraging modalities. Each mesocosm contained eight passively foraging pink sundews, and we employed an experimental design where treatments were the presence or absence of a sit-and-wait foraging spider and actively foraging toad crossed with five levels of prey abundance. We hypothesized that actively foraging toads would outcompete the other species at low prey abundance, but that spiders and sundews would exhibit plasticity in foraging traits to compensate for strong competition when prey were limited. Results generally supported our hypotheses. Toads had a greater effect on sundews at low prey abundances, and toad presence caused spiders to locate webs higher above the ground. Additionally, the closer large spider webs were to the ground, the greater the trichome densities produced by sundews. Also, spider webs were larger with than without toads and as sundew numbers increased, and these effects were more prominent as resources became limited. Finally, spiders negatively affected toad growth only at low prey abundance. These findings highlight the long-term importance of foraging modality and plasticity of foraging traits in determining the strength of competition within and across taxonomic kingdoms. Future research should assess whether plasticity in foraging traits helps to maintain coexistence within this guild and whether foraging modality can be used as a trait to reliably predict the strength of competitive interactions. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

  4. Experimental evaluation of the interaction between strength concrete block walls under vertical loads

    Directory of Open Access Journals (Sweden)

    L. O. CASTRO

    Full Text Available Abstract This paper aims to evaluate the interaction between structural masonry walls made of high performance concrete blocks, under vertical loads. Two H-shaped flanged wall series, all full scale and using direct bond, have been analyzed experimentally. In one series, three flanged-walls were built with the central wall (web supported and, in the other one, three specimens were built without any support at the central web. The load was applied on the central wall and vertical displacements were measured by means of displacement transducers located at eighteen points in the wall-assemblages. The results showed that the estimated load values for the flanges were close to those supported by the walls without central support, where 100% of the load transfer to the flanges occur. The average transfer load rate calculated based on the deformation ratio in the upper and lower section of the flanged-walls, with the central web support, were 37.65% and 77.30%, respectively, showing that there is load transfer from the central wall (web toward the flanges, particularly in the lower part of the flanged walls. Thus, there is indication that the distribution of vertical loads may be considered for projects of buildings for service load, such as in the method of isolated walls group. For estimation of the failure load, the method that considers the walls acting independently showed better results, due to the fact that failure started at the top of the central wall, where there is no effect of load distribution from the adjacent walls.

  5. Energy dependence of the ratio of isovector effective interaction strengths |JστJτ| from 0° (p,n) cross sections

    Science.gov (United States)

    Taddeucci, T. N.; Rapaport, J.; Bainum, D. E.; Goodman, C. D.; Foster, C. C.; Gaarde, C.; Larsen, J.; Goulding, C. A.; Horen, D. J.; Masterson, T.; Sugarbaker, E.

    1982-02-01

    Information concerning the ratio of the isovector effective interaction strengths |JστJτ| may be obtained from the ratio of (p,n) Gamow-Teller and isobaric analog state 0° differential cross sections. We have examined 0° (p,n) data for the energy range 5-200 MeV and find that for energies larger than 50 MeV and for targets with A=7-42 the product of the interaction-strength and distortion-factor ratios |JστJτ|(NστNτ)12 appears to be mass independent and linear as a function of bombarding energy. NUCLEAR REACTIONS 7Li, 13, 14C, 26Mg, 37Cl, 41Ca(p,n), measured σ(θ=0°), GT, IAS transitions, Ep=60-200 MeV. Deduced energy dependence, interaction strength ratio |JστJτ|.

  6. Coulomb-nuclear interference (CNI) results of the collective quadrupolar excitations in odd and even Ru isotopes

    International Nuclear Information System (INIS)

    Rodrigues, C.L.; Rodrigues, M.R.D.; Borello-Lewin, T.; Horodynski-Matsushigue, L.B.; Duarte, J. L.M.; Hanninger, G.N.; Ukita, G.M.

    2004-01-01

    The study of the odd 99,101 Ru nuclei complements the investigation of the collectivity of the first quadrupolar excitations in 100,102,104 Ru. Angular distributions for the 99,101 Ru(d, d') reactions at 13 MeV were obtained in the Pelletron Laboratory using nuclear emulsion plates on the focal plane of the Enge spectrograph. A Coulomb- Nuclear Interference analysis employing DWBA-DOMP predictions with global optical potential parameters was applied to the excitation of states which could belong to the multiplet built on the first quadrupolar excitation of the core. In the analysis, three states were identified for each of the isotopes and associated, respectively, with adopted levels in the Nuclear Data Sheets Compilation of Jπ = 5=2 + , 7=2 + and 9=2 + . Through the comparison of experimental and predicted cross section angular distributions, the values of (δ L N ) 2 and of the ratio C = δ L C /δ L N were obtained. (author)

  7. Coulomb-nuclear interference (CNI) results of the collective quadrupolar excitations in odd and even Ru isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, C.L.; Rodrigues, M.R.D.; Borello-Lewin, T.; Horodynski-Matsushigue, L.B.; Duarte, J. L.M.; Hanninger, G.N. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Ukita, G.M. [Universidade de Santo Amaro, SP (Brazil). Faculdade de Psicologia

    2004-09-15

    The study of the odd {sup 99,101}Ru nuclei complements the investigation of the collectivity of the first quadrupolar excitations in {sup 100,102,104}Ru. Angular distributions for the {sup 99,101}Ru(d, d') reactions at 13 MeV were obtained in the Pelletron Laboratory using nuclear emulsion plates on the focal plane of the Enge spectrograph. A Coulomb- Nuclear Interference analysis employing DWBA-DOMP predictions with global optical potential parameters was applied to the excitation of states which could belong to the multiplet built on the first quadrupolar excitation of the core. In the analysis, three states were identified for each of the isotopes and associated, respectively, with adopted levels in the Nuclear Data Sheets Compilation of J{pi} = 5=2{sup +}, 7=2{sup +} and 9=2{sup +}. Through the comparison of experimental and predicted cross section angular distributions, the values of ({delta}{sup L}{sub N}){sup 2} and of the ratio C = {delta}{sub L}{sup C} /{delta}{sub L}{sup N} were obtained. (author)

  8. Influence of magnetic dipole and magnetoelastic interactions on the phase states of 2D non-Heisenberg ferromagnetic with complex exchange interactions

    International Nuclear Information System (INIS)

    Fridman, Yu.A.; Matunin, D.A.; Klevets, Ph.N.; Kosmachev, O.A.

    2009-01-01

    The phase states of the 2D non-Heisenberg ferromagnetic with anisotropic bilinear and biquadratic exchange interactions are investigated. The limiting cases of the system under consideration are the two-dimensional XY-model with biquadratic exchange interaction and the isotropic Heisenberg ferromagnetic. The account of the magnetic dipole interaction leads to the realization of spatially inhomogeneous quadrupolar phase. The stability regions of various phase transitions for different values of the material parameters are studied. The phase diagram is built. Besides, the temperature phase transitions are investigated. The influence of the magnetoelastic interaction on the formation of the long-range quadrupolar order is determined.

  9. Cold molecules: formation, trapping and spectroscopy. - Piling up of cesium dimers in a quadrupolar magnetic trap. - Spectroscopy by lack of photo-association

    International Nuclear Information System (INIS)

    Vanhaecke, N.

    2003-10-01

    This thesis deals with the study of cold molecules obtained through the cold atom photo-association technique. Our study is focused both on manipulating external degrees of freedom of these Cs 2 molecules and on studying their internal interactions. A quadrupolar magnetic trap of about 2.10 5 cold Cs 2 molecules is demonstrated. The trap lifetime is on the order of 600 ms, mainly limited by the background gas pressure. The trapped molecules are identified, which allows the determination of the trapped molecule cloud temperature, which is about 35 μK. A dipolar trap is set up by the use of a focused CO 2 laser beam. Moreover, this thesis describes a two-photon photo-association spectroscopy. We report the first study of two-photon photo-association line shapes, which exhibit typical Fano profiles. Taking advantage of the detailed understanding of these line shapes, we measure over one hundred high-lying level energies with an accuracy on the order of 10 MHz. Then we interpret theoretically these energies. The huge hyperfine structure of the Cesium atom binds us to solve a coupled channel Schroedinger equation for internuclear distances above 15 a 0 . Hence we use an asymptotic theory to fit the potential parameters of the Cs 2 dimer. We adjust those parameters by the mean of both evolutionary strategies and deterministic optimum seeking. This is followed by a careful statistics study, which leads to a very accurate determination of the Vander Waals coefficient. Moreover we report the first experimental determination of the exchange interaction amplitude. (author)

  10. Configuration-interaction relativistic-many-body-perturbation-theory calculations of photoionization cross sections from quasicontinuum oscillator strengths

    International Nuclear Information System (INIS)

    Savukov, I. M.; Filin, D. V.

    2014-01-01

    Many applications are in need of accurate photoionization cross sections, especially in the case of complex atoms. Configuration-interaction relativistic-many-body-perturbation theory (CI-RMBPT) has been successful in predicting atomic energies, matrix elements between discrete states, and other properties, which is quite promising, but it has not been applied to photoionization problems owing to extra complications arising from continuum states. In this paper a method that will allow the conversion of discrete CI-(R)MPBT oscillator strengths (OS) to photoionization cross sections with minimal modifications of the codes is introduced and CI-RMBPT cross sections of Ne, Ar, Kr, and Xe are calculated. A consistent agreement with experiment is found. RMBPT corrections are particularly significant for Ar, Kr, and Xe and improve agreement with experimental results compared to the particle-hole CI method. As a result, the demonstrated conversion method can be applied to CI-RMBPT photoionization calculations for a large number of multivalence atoms and ions

  11. Effect of Web Holes and Bearing Stiffeners on Flexural-Shear Interaction Strength of Steel Cold-Formed C-Channel Sections

    Directory of Open Access Journals (Sweden)

    Iman Faridmehr

    Full Text Available Abstract This paper presents an investigation on interaction equation between the required flexural strength, M, and the required shear strength, V, of cold-formed C-channels with web holes and bearing stiffeners. The primarily shear condition test was employed to study total 8 back to back lipped C channel sections of 95 and 100 mm depth when bearing stiffeners and circular holes were placed at center and both ends of specimens. The interaction equation were evaluated via Direct Strength Method, DSM, in accordance with the American Iron and Steel Institute for the design of cold-formed steel structural members, AISI 2007. A nonlinear finite element model was developed and verified against the test results in terms of failure buckling modes. It was concluded that the M-V interaction equation for specimens with web stiffeners was conservative where these specimens experienced plastic failure mode rather than local (Msl or distortional (Msd buckling mode. Moreover, the results indicated that proposed M-V interaction equation calculated by local buckling strength (Msl adequately predicted the behavior of specimens with circular web holes.

  12. Theoretical and experimental investigation of the electromagnetic adjustment of a quadrupolar radio-frequency cavity accelerating an intense ion beam

    International Nuclear Information System (INIS)

    Simoens, Francois

    2002-01-01

    The first part of this research thesis describes radio-frequency quadrupolar (RFQ) cavities in terms of electrostatic and electro-dynamic properties. It describes the construction of a RFQ four-wire model which leads to a differential equation describing the cavity electromagnetic behaviour. The operator spectral theory allows the eigenvalue problem to be solved. An experimental methodology applied to this cavity is presented, and experimental studies are reported with a good correlation between the model resonance modes and measurements performed on the mock-up. The second part reports the development of a mathematical formulation based on the perturbation of line parameters of the previously developed model. This allows the assessment of mechanical defects and of tuning piston control

  13. [Verification of a decrease in the rigidity of the phage lambda DNA polymeric chain in low ionic strength aqueous solutions by testing the polymer-polymer interlink interactions].

    Science.gov (United States)

    Arutiunian, A V; Ivanova, M A; Kurliand, D I; Kapshin, Iu S; Landa, S B; Poshekhonov, S T; Drobchenko, E A; Shevelev, I V

    2011-01-01

    Changes in the rigidity of the polymetric chain of phage lambda double-strand DNA have been studied by laser correlation spectroscopy. It was shown that, as the ionic strength increases, the effect of the screening of the hydrodynamic interaction of the links of the polymeric chain specific for polymeric coils arises in a DNA solution. It is assumed that the screening occurs when the threshold of the overlapping of DNA coils is achieved. The overlapping of coils is the result of a previously observed significant rise of DNA coil size from abnormally small DNA coils in low ionic strength buffers (about 10(-2) M Na+ or less) to maximum possible large coils in the 5SSC and 5SSC-like buffers. Further analysis of the far interlink interactions in linear lambda phage DNA coils in similar buffers at pH 7 and 4 confirms the earlier proposal about the role of H+ ions in the appearance of abnormally small DNA coils. The abnormal decrease in the DNA coil size in low ionic strength buffers is not a specific feature of lambda phage DNA only.

  14. Silicone Foul Release Coatings: Effect of the Interaction of Oil and Coating Functionalities on the Magnitude of Macrofouling Attachment Strengths

    Science.gov (United States)

    2003-01-01

    Hawaii) is described. The response of tubeworms (Hydroides elegans, Hydroides dianthus ), oysters (Ostrea sp., Crassostrea sp.) and barnacles (Balanus...8 and Hydroides dianthus ) and oysters (Ostrea sp. and Crassostrea sp.) to the silicone coatings were measured using ASTM D 5618-94 (1994), in which...Oyster (Crassostrea sp.) and tubeworm (H. dianthus ) attachment strengths at the Indian River Lagoon site Linear regression analyses of the adhesion

  15. A study of isotropic-nematic transition of quadrupolar Gay-Berne fluid using density-functional theory approach

    Science.gov (United States)

    Singh, Ram Chandra; Ram, Jokhan

    2011-11-01

    The effects of quadrupole moments on the isotropic-nematic (IN) phase transitions are studied using the density-functional theory (DFT) for a Gay-Berne (GB) fluid for a range of length-to-breadth parameters ? in the reduced temperature range ? . The pair-correlation functions of the isotropic phase, which enter into the DFT as input parameters are found by solving the Percus-Yevick integral equation theory. The method used involves an expansion of angle-dependent functions appearing in the integral equations in terms of spherical harmonics and the harmonic coefficients are obtained by an iterative algorithm. All the terms of harmonic coefficients which involve l indices up to less than or equal to 6 are considered. The numerical accuracy of the results depends on the number of spherical harmonic coefficients considered for each orientation-dependent function. As the length-to-breadth ratio of quadrupolar GB molecules is increased, the IN transition is seen to move to lower density (and pressure) at a given temperature. It has been observed that the DFT is good to study the IN transitions in such fluids. The theoretical results have also been compared with the computer simulation results wherever they are available.

  16. Investigation of timing effects in modified composite quadrupolar echo pulse sequences by mean of average Hamiltonian theory

    Science.gov (United States)

    Mananga, Eugene Stephane

    2018-01-01

    The utility of the average Hamiltonian theory and its antecedent the Magnus expansion is presented. We assessed the concept of convergence of the Magnus expansion in quadrupolar spectroscopy of spin-1 via the square of the magnitude of the average Hamiltonian. We investigated this approach for two specific modified composite pulse sequences: COM-Im and COM-IVm. It is demonstrated that the size of the square of the magnitude of zero order average Hamiltonian obtained on the appropriated basis is a viable approach to study the convergence of the Magnus expansion. The approach turns to be efficient in studying pulse sequences in general and can be very useful to investigate coherent averaging in the development of high resolution NMR technique in solids. This approach allows comparing theoretically the two modified composite pulse sequences COM-Im and COM-IVm. We also compare theoretically the current modified composite sequences (COM-Im and COM-IVm) to the recently published modified composite pulse sequences (MCOM-I, MCOM-IV, MCOM-I_d, MCOM-IV_d).

  17. Thermal fatigue strength estimation of 2.25Cr-1Mo steel under creep-fatigue interaction

    International Nuclear Information System (INIS)

    Kuwahara, Kazuo; Nitta, Akihito; Kitamura, Takayuki

    1980-01-01

    A 2-1/4Cr-1Mo steel is one of principal materials for high temperature equipments in nuclear and thermal power plants. The authors experimentally analyzed the high temperature fatigue strength and creep strength of a 2-1/4 Cr-1Mo steel main steam pipe which had been used in a thermal plant for operation up to 130,000 hours, and pointed out that the strain-range vs. life curves crossed each other due to the difference of temperature-strain phase in thermal fatigue. This suggests that it is difficult to estimate thermal fatigue life of steel materials having been subjected to different temperature-strain phase on the basis of isothermal low-cycle fatigue life at the upper limit temperature of thermal fatigue, and that it is urgently required to establish an appropriate method of evaluating thermal fatigue life. The authors attempted to prove that the strain range partitioning method used for the evaluation of thermal fatigue life in SUS 304 steels is applicable to this 2-1/4Cr-1Mo steel. Consequently, it was found that the thermal fatigue life could be estimated within a factor of 2.5 by the application of this method. (author)

  18. Interaction of nucleic acids with electrically charged surfaces. VII. The effect of ionic strength of neutral medium on the conformation of dna adsorbed on the mercury electrode.

    Science.gov (United States)

    Brabec, V

    1980-02-01

    Triangular-wave direct current (d.c.) voltammetry at a hanging mercury drop electrode and phase-selective alternating current (a.c.) polarography at a dropping mercury electrode were used for the investigation of adsorption of double-helical (ds) DNA at mercury electrode surfaces from neutral solutions of 0.05-0.4 M HCOONH4. It was found for the potential region T (from -0.1 V up to ca. -1.0 V) that the height of voltammetric peaks of ds DNA is markedly influenced by the initial potential only at relatively low ionic strength (mu) (from 0.05 up to ca. 0.3). Also a decrease of differential capacity (measured by means of a.c. polarography) in the region T depended markedly on the electrode potential only at relatively low ionic strength. The following conclusions were made concerning the interaction of ds DNA with a mercury electrode charged to potentials of the region T in neutral medium of relatively low ionic strength mu potentials in the Vicinity of the zero charge potential a higher number of ds DNA segments can be opened, probably as a consequence of the strain which could act on the ds DNA molecule in the course of the segmental adsorption/desorption process.

  19. Influence of the Rashba and Dresselhaus spin-orbit interactions of equal strength on the electron states in the circular quantum ring in the presence of a magnetic field

    International Nuclear Information System (INIS)

    Kudryashov, V.V.; Baran, A.V.

    2012-01-01

    The solutions of the Schrodinger equation are obtained for an electron in the two-dimensional circular semiconductor quantum ring in the presence of both an external magnetic and the Rashba and Dresselhaus spin-orbit interactions of equal strength . Confinement is simulated by a realistic potential well of finite depth. The dependence of energy levels on the magnetic field, the strength of spin-orbit interaction, and the relative ring width is presented. (authors)

  20. Influence of the Rashba and Dresselhaus spin-orbit interactions of equal strength on the electron states in the circular quantum dot in the presence of a magnetic field

    International Nuclear Information System (INIS)

    Kudryashov, V.V.; Baran, A.V.

    2012-01-01

    The solutions of the Schrodinger equation are obtained for an electron at a two-dimensional circular semiconductor quantum dot in the presence of both an external magnetic field and the Rashba and Dresselhaus spin-orbit interactions of equal strength. Confinement is simulated by a realistic potential well of finite depth. The dependence of energy levels on a magnetic field and a strength of spin-orbit interaction is presented. (authors)

  1. Control of strength and stability of emulsion-gels by a combination of long- and short-range interactions

    NARCIS (Netherlands)

    Blijdenstein, T.B.J.; Hendriks, W.P.G.; Linden, van der E.; Vliet, van T.; Aken, van G.A.

    2003-01-01

    This paper discusses the change in phase behavior and mechanical properties of oil-in-water emulsion gels brought about by variation of long- and short-range attractive interactions. The model system studied consisted of oil droplets stabilized by the protein -lactoglobulin (-lg). A long-range

  2. AFM force spectroscopy reveals how subtle structural differences affect the interaction strength between Candida albicans and DC-SIGN

    NARCIS (Netherlands)

    Riet, J. te; Reinieren-Beeren, I.M.J.; Figdor, C.G.; Cambi, A.

    2015-01-01

    The fungus Candida albicans is the most common cause of mycotic infections in immunocompromised hosts. Little is known about the initial interactions between Candida and immune cell receptors, such as the C-type lectin dendritic cell-specific intracellular cell adhesion molecule-3 (ICAM-3)-grabbing

  3. Multiple effects of S13 in modulating the strength of intersubunit interactions in the ribosome during translation.

    Science.gov (United States)

    Cukras, Anthony R; Green, Rachel

    2005-05-27

    The ribosomal protein S13 is found in the head region of the small subunit, where it interacts with the central protuberance of the large ribosomal subunit and with the P site-bound tRNA through its extended C terminus. The bridging interactions between the large and small subunits are dynamic, and are thought to be critical in orchestrating the molecular motions of the translation cycle. S13 provides a direct link between the tRNA-binding site and the movements in the head of the small subunit seen during translocation, thereby providing a possible pathway of signal transduction. We have created and characterized an rpsM(S13)-deficient strain of Escherichia coli and have found significant defects in subunit association, initiation and translocation through in vitro assays of S13-deficient ribosomes. Targeted mutagenesis of specific bridge and tRNA contact elements in S13 provides evidence that these two interaction domains play critical roles in maintaining the fidelity of translation. This ribosomal protein thus appears to play a non-essential, yet important role by modulating subunit interactions in multiple steps of the translation cycle.

  4. Interaction between lysozyme and humic acid in layer-by-layer assemblies: Effects of pH and ionic strength

    NARCIS (Netherlands)

    Tan, W.F.; Norde, W.; Koopal, L.K.

    2014-01-01

    The interaction between protein and soluble organic matter is studied through layer-by-layer assembly of lysozyme (LSZ) and purified Aldrich humic acid (PAHA) at a solid surface (2-D) and in solution (3-D). By bringing a silica surface in alternating contact with solutions of LSZ and PAHA a

  5. Interaction between lysozyme and humic acid in layer-by-layer assemblies : Effects of pH and ionic strength

    NARCIS (Netherlands)

    Tan, Wenfeng; Norde, Willem; Koopal, Luuk K.

    2014-01-01

    The interaction between protein and soluble organic matter is studied through layer-by-layer assembly of lysozyme (LSZ) and purified Aldrich humic acid (PAHA) at a solid surface (2-D) and in solution (3-D). By bringing a silica surface in alternating contact with solutions of LSZ and PAHA a

  6. The solvent at antigen-binding site regulated C3d-CR2 interactions through the C-terminal tail of C3d at different ion strengths: insights from molecular dynamics simulation.

    Science.gov (United States)

    Zhang, Yan; Guo, Jingjing; Li, Lanlan; Liu, Xuewei; Yao, Xiaojun; Liu, Huanxiang

    2016-10-01

    The interactions of complement receptor 2 (CR2) and the degradation fragment C3d of complement component C3 play important links between the innate and adaptive immune systems. Due to the importance of C3d-CR2 interaction in the design of vaccines and inhibitors, a number of studies have been performed to investigate C3d-CR2 interaction. Many studies have indicated C3d-CR2 interactions are ionic strength-dependent. To investigate the molecular mechanism of C3d-CR2 interaction and the origin of effects of ionic strength, molecular dynamics simulations for C3d-CR2 complex together with the energetic and structural analysis were performed. Our results revealed the increased interactions between charged protein and ions weaken C3d-CR2 association, as ionic strengths increase. Moreover, ion strengths have similar effects on antigen-binding site and CR2 binding site. Meanwhile, Ala17 and Gln20 will transform between the activated and non-activated states mediated by His133 and Glu135 at different ion strengths. Our results reveal the origins of the effects of ionic strengths on C3d-CR2 interactions are due to the changes of water, ion occupancies and distributions. This study uncovers the origin of the effect of ionic strength on C3d-CR2 interaction and deepens the understanding of the molecular mechanism of their interaction, which is valuable for the design of vaccines and small molecule inhibitors. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Measuring the strength of interaction between the Ebola fusion peptide and lipid rafts: implications for membrane fusion and virus infection.

    Directory of Open Access Journals (Sweden)

    Mônica S Freitas

    Full Text Available The Ebola fusion peptide (EBO₁₆ is a hydrophobic domain that belongs to the GP2 membrane fusion protein of the Ebola virus. It adopts a helical structure in the presence of mimetic membranes that is stabilized by the presence of an aromatic-aromatic interaction established by Trp8 and Phe12. In spite of its infectious cycle becoming better understood recently, several steps still remain unclear, a lacuna that makes it difficult to develop strategies to block infection. In order to gain insight into the mechanism of membrane fusion, we probed the structure, function and energetics of EBO₁₆ and its mutant W8A, in the absence or presence of different lipid membranes, including isolated domain-resistant membranes (DRM, a good experimental model for lipid rafts. The depletion of cholesterol from living mammalian cells reduced the ability of EBO₁₆ to induce lipid mixing. On the other hand, EBO₁₆ was structurally sensitive to interaction with lipid rafts (DRMs, but the same was not observed for W8A mutant. In agreement with these data, W8A showed a poor ability to promote membrane aggregation in comparison to EBO₁₆. Single molecule AFM experiments showed a high affinity force pattern for the interaction of EBO₁₆ and DRM, which seems to be a complex energetic event as observed by the calorimetric profile. Our study is the first to show a strong correlation between the initial step of Ebola virus infection and cholesterol, thus providing a rationale for Ebola virus proteins being co-localized with lipid-raft domains. In all, the results show how small fusion peptide sequences have evolved to adopt highly specific and strong interactions with membrane domains. Such features suggest these processes are excellent targets for therapeutic and vaccine approaches to viral diseases.

  8. Measuring the strength of interaction between the Ebola fusion peptide and lipid rafts: implications for membrane fusion and virus infection.

    Science.gov (United States)

    Freitas, Mônica S; Follmer, Cristian; Costa, Lilian T; Vilani, Cecília; Bianconi, M Lucia; Achete, Carlos Alberto; Silva, Jerson L

    2011-01-13

    The Ebola fusion peptide (EBO₁₆) is a hydrophobic domain that belongs to the GP2 membrane fusion protein of the Ebola virus. It adopts a helical structure in the presence of mimetic membranes that is stabilized by the presence of an aromatic-aromatic interaction established by Trp8 and Phe12. In spite of its infectious cycle becoming better understood recently, several steps still remain unclear, a lacuna that makes it difficult to develop strategies to block infection. In order to gain insight into the mechanism of membrane fusion, we probed the structure, function and energetics of EBO₁₆ and its mutant W8A, in the absence or presence of different lipid membranes, including isolated domain-resistant membranes (DRM), a good experimental model for lipid rafts. The depletion of cholesterol from living mammalian cells reduced the ability of EBO₁₆ to induce lipid mixing. On the other hand, EBO₁₆ was structurally sensitive to interaction with lipid rafts (DRMs), but the same was not observed for W8A mutant. In agreement with these data, W8A showed a poor ability to promote membrane aggregation in comparison to EBO₁₆. Single molecule AFM experiments showed a high affinity force pattern for the interaction of EBO₁₆ and DRM, which seems to be a complex energetic event as observed by the calorimetric profile. Our study is the first to show a strong correlation between the initial step of Ebola virus infection and cholesterol, thus providing a rationale for Ebola virus proteins being co-localized with lipid-raft domains. In all, the results show how small fusion peptide sequences have evolved to adopt highly specific and strong interactions with membrane domains. Such features suggest these processes are excellent targets for therapeutic and vaccine approaches to viral diseases.

  9. The interaction between non-metallic inclusions and surface roughness in fatigue failure and their influence on fatigue strength

    International Nuclear Information System (INIS)

    Saberifar, S.; Mashreghi, A.R.; Mosalaeepur, M.; Ghasemi, S.S.

    2012-01-01

    Highlights: ► The fatigue strength of a tested steel was affected by inclusions and surface notches. ► Inclusions were the main fatigue crack sources even in rough specimens. ► The stress intensity factor represented the behavior of inclusions properly. ► In rough steels the effect of inclusions was intensified by surface roughness. ► The critical inclusion size increased when surface roughness was removed. -- Abstract: In this study, the influence of non-metallic inclusions on the fatigue behavior of 30MnVS6 steel containing different inclusion sizes and surface roughness has been investigated. Scanning electron microscope (SEM) was used to examine fatigue fracture origins. It was concluded that the non-metallic inclusions were dominant fatigue crack initiation sites in both smooth and rough specimens. This was justified by the calculation of stress intensity factor generated by both surface roughness and non-metallic inclusions, based on Murakami’s model. In addition, it was found that for a given stress, the critical inclusion size could be increased by eliminating the surface roughness.

  10. AFM force spectroscopy reveals how subtle structural differences affect the interaction strength between Candida albicans and DC-SIGN.

    Science.gov (United States)

    te Riet, Joost; Reinieren-Beeren, Inge; Figdor, Carl G; Cambi, Alessandra

    2015-11-01

    The fungus Candida albicans is the most common cause of mycotic infections in immunocompromised hosts. Little is known about the initial interactions between Candida and immune cell receptors, such as the C-type lectin dendritic cell-specific intracellular cell adhesion molecule-3 (ICAM-3)-grabbing non-integrin (DC-SIGN), because a detailed characterization at the structural level is lacking. DC-SIGN recognizes specific Candida-associated molecular patterns, that is, mannan structures present in the cell wall of Candida. The molecular recognition mechanism is however poorly understood. We postulated that small differences in mannan-branching may result in considerable differences in the binding affinity. Here, we exploit atomic force microscope-based dynamic force spectroscopy with single Candida cells to gain better insight in the carbohydrate recognition capacity of DC-SIGN. We demonstrate that slight differences in the N-mannan structure of Candida, that is, the absence or presence of a phosphomannan side chain, results in differences in the recognition by DC-SIGN as follows: (i) it contributes to the compliance of the outer cell wall of Candida, and (ii) its presence results in a higher binding energy of 1.6 kB T. The single-bond affinity of tetrameric DC-SIGN for wild-type C. albicans is ~10.7 kB T and a dissociation constant kD of 23 μM, which is relatively strong compared with other carbohydrate-protein interactions described in the literature. In conclusion, this study shows that DC-SIGN specifically recognizes mannan patterns on C. albicans with high affinity. Knowledge on the binding pocket of DC-SIGN and its pathogenic ligands will lead to a better understanding of how fungal-associated carbohydrate structures are recognized by receptors of the immune system and can ultimately contribute to the development of new anti-fungal drugs. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Body size affects the strength of social interactions and spatial organization of a schooling fish (Pseudomugil signifer)

    Science.gov (United States)

    Romenskyy, Maksym; Herbert-Read, James E.; Ward, Ashley J. W.; Sumpter, David J. T.

    2017-04-01

    While a rich variety of self-propelled particle models propose to explain the collective motion of fish and other animals, rigorous statistical comparison between models and data remains a challenge. Plausible models should be flexible enough to capture changes in the collective behaviour of animal groups at their different developmental stages and group sizes. Here, we analyse the statistical properties of schooling fish (Pseudomugil signifer) through a combination of experiments and simulations. We make novel use of a Boltzmann inversion method, usually applied in molecular dynamics, to identify the effective potential of the mean force of fish interactions. Specifically, we show that larger fish have a larger repulsion zone, but stronger attraction, resulting in greater alignment in their collective motion. We model the collective dynamics of schools using a self-propelled particle model, modified to include varying particle speed and a local repulsion rule. We demonstrate that the statistical properties of the fish schools are reproduced by our model, thereby capturing a number of features of the behaviour and development of schooling fish.

  12. Direct observation of spin-quadrupolar excitations in Sr2CoGe2O7 by high-field electron spin resonance

    Science.gov (United States)

    Akaki, Mitsuru; Yoshizawa, Daichi; Okutani, Akira; Kida, Takanori; Romhányi, Judit; Penc, Karlo; Hagiwara, Masayuki

    2017-12-01

    Exotic spin-multipolar ordering in spin transition metal insulators has so far eluded unambiguous experimental observation. A less studied, but perhaps more feasible fingerprint of multipole character emerges in the excitation spectrum in the form of quadrupolar transitions. Such multipolar excitations are desirable as they can be manipulated with the use of light or electric field and can be captured by means of conventional experimental techniques. Here we study single crystals of multiferroic Sr2CoGe2O7 and observe a two-magnon spin excitation appearing above the saturation magnetic field in electron spin resonance (ESR) spectra. Our analysis of the selection rules reveals that this spin excitation mode does not couple to the magnetic component of the light, but it is excited by the electric field only, in full agreement with the theoretical calculations. Due to the nearly isotropic nature of Sr2CoGe2O7 , we identify this excitation as a purely spin-quadrupolar two-magnon mode.

  13. High temperature strength data-base of SUS304 steel and a study on life prediction method under ceep-fatigue interaction

    International Nuclear Information System (INIS)

    Matsubara, Masaaki; Nitta, Akito; Ogata, Takashi; Kuwabara, Kazuo

    1985-01-01

    As a part of ''Study for practical use of Tank Type FBR'', ''Practical use of inelastic analysis method to FBR structural design'' is carried out as a cooperative study for three years from 1984. In this cooperative study, to establish the life prediction method under creep-fatigue interaction is one of the most important theme. To attain this purpose, many different type tests are planned and then conducted. By the way, to use these many data rapidly and effectively, it is necessary to make a data base. So in this work, we developed the simple data base of high temperature strength. And the data of SUS304 obtained at this place to this day are inputted into this data base. Next, we investigated about five life prediction methods under creep-fatigue interaction, Frequency Modified Method, Ostergren Method, Strain Range Partitioning Method, Damage Rate Approach and Strain Energy Parameter Method. As a result, Strain Range Partitioning Method can predict the lives within Factor of 2. In the other four methods, it is supported that material constants in the prediction formula are dependent on temperature. (author)

  14. On the microstructural basis of creep strength and creep-fatigue interaction in 9-12 % Cr steels for application in power plants

    Energy Technology Data Exchange (ETDEWEB)

    Chilukuru, H

    2007-03-06

    As part of the efforts of preserving the environment it is necessary to reduce of the CO2 emissions from power plants. This can be done by increasing the plant efficiency. Research groups around the world are engaged in developing new steels capable of sustaining higher stresses and temperatures envisaged for high-efficiency power plants. Research carried out in Europe is organized within the COST Programme (Co-Operation in Science and Technology) aiming at replacing the conventional steels of type X20CrMoV121 by the new class of 9-12% Cr-steels with modified composition. The resistance of materials against deformation at elevated temperatures depends on their microstructure. Frequently in 9-12% Cr-steels improved short-term creep properties do not persist in the long-term service [1, 2, 3, 4, 5, 6]. This is related with insufficient microstructural stability. Hardening contributions in 9-12% Cr-steels come from solute atoms of the ferritic matrix, from dislocations, and from precipitates of foreign phases within the matrix. The term ''carbide stabilized substructure hardening'' of 9-12% Cr steels [7, 8] indicates that the hardening contributions are interdependent. The dislocations are the carriers of plastic deformation. They interact with each other, with solute atoms and with precipitates. The dislocation-dislocation interaction leads to formation of planar dislocation networks constituting low-angle boundaries. They form a subgrain structure within the grains. At present, a full and detailed understanding of the effects exerted by the different components of microstructure on creep strength is still lacking. The present work makes a contribution to the efforts of understanding the microstructural basis of creep strength and of creep-fatigue interaction by transmission electron microscopic structure investigations coupled with creep tests. Investigations by transmission electron microscopy (TEM) were carried out with regard to hardening by subgrain boundaries

  15. On the microstructural basis of creep strength and creep-fatigue interaction in 9-12 % Cr steels for application in power plants

    Energy Technology Data Exchange (ETDEWEB)

    Chilukuru, H.

    2007-03-06

    As part of the efforts of preserving the environment it is necessary to reduce of the CO2 emissions from power plants. This can be done by increasing the plant efficiency. Research groups around the world are engaged in developing new steels capable of sustaining higher stresses and temperatures envisaged for high-efficiency power plants. Research carried out in Europe is organized within the COST Programme (Co-Operation in Science and Technology) aiming at replacing the conventional steels of type X20CrMoV121 by the new class of 9-12% Cr-steels with modified composition. The resistance of materials against deformation at elevated temperatures depends on their microstructure. Frequently in 9-12% Cr-steels improved short-term creep properties do not persist in the long-term service [1, 2, 3, 4, 5, 6]. This is related with insufficient microstructural stability. Hardening contributions in 9-12% Cr-steels come from solute atoms of the ferritic matrix, from dislocations, and from precipitates of foreign phases within the matrix. The term ''carbide stabilized substructure hardening'' of 9-12% Cr steels [7, 8] indicates that the hardening contributions are interdependent. The dislocations are the carriers of plastic deformation. They interact with each other, with solute atoms and with precipitates. The dislocation-dislocation interaction leads to formation of planar dislocation networks constituting low-angle boundaries. They form a subgrain structure within the grains. At present, a full and detailed understanding of the effects exerted by the different components of microstructure on creep strength is still lacking. The present work makes a contribution to the efforts of understanding the microstructural basis of creep strength and of creep-fatigue interaction by transmission electron microscopic structure investigations coupled with creep tests. Investigations by transmission electron microscopy (TEM) were carried out with regard to hardening by

  16. Introduction to interacting boson model

    International Nuclear Information System (INIS)

    Goutte, D.

    1986-01-01

    A very simple presentation of the interacting boson model is first given. The two computerized models which are presented allow, with few parameters, to reproduce an impressive quantity of data characterizing the deformed nuclei. Their excitation spectra, the reduced transition probabilities, the quadrupolar moments, the two nucleon transfer experiment results, ... Then a specific application of the model is given: radial extension reproduction of nuclear functions. It is shown first how the electron inelastic scattering allows to measure observables related to these radial functions, the transition charge densities, then, on some examples, how the model allows to reproduce them [fr

  17. Juno-UVS observation of the Io footprint: Influence of Io's local environment and passage into eclipse on the strength of the interaction

    Science.gov (United States)

    Hue, V.; Gladstone, R.; Greathouse, T. K.; Versteeg, M.; Bonfond, B.; Saur, J.; Davis, M. W.; Roth, L.; Grodent, D. C.; Gerard, J. C. M. C.; Kammer, J.; Bolton, S. J.; Levin, S.; Connerney, J. E. P.

    2017-12-01

    The Juno mission offers an unprecedented opportunity to study Jupiter, from its internal structure to its magnetospheric environment. Juno-UVS is a UV spectrograph with a bandpass of 70vantage point above the poles. In particular, UVS has observed the instantaneous Io footprint and extended tail as Io enters into eclipse. This observation may better constrain whether the atmosphere of Io is sustained via volcanic activity or sublimation. Among other processes, the modulation of Io's footprint brightness correlates to the strength of the interaction between the Io plasma torus and its ionosphere, which, in turn, is likely to be affected by the atmospheric collapse. UVS observed the Io footprint during two eclipses that occurred on PJ1 and PJ3, and one additional eclipse observation is planned during PJ9 (24 Oct. 2017). We present how the electrodynamic coupling between Io and Jupiter is influenced by changes in Io's local environment, e.g. Io's passage in and out of eclipse and Io's traverse of the magnetodisc plasma sheet.

  18. Experimental Determination of Lead Interactions with Citrate and EDTA in NaCl and MgCl2 Solutions to High Ionic Strength and Its Applications.

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Yongliang [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Kirkes, Leslie Dawn [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Westfall, Terry [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Marrs, Cassandra [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Knox, Jandi [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Burton, Heather Lynn [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group

    2017-09-01

    For this study, the interactions of lead with citrate and ethylenediaminetetraacetate (EDTA) are investigated based on solubility measurements as a function of ionic strength at room temperature (22.5 ± 0.5°C) in NaCl and MgCl2 solutions. The formation constants (log β10 ) for Pb[C3H5O(COO)3]– (abbreviated as PbCitrate) and Pb[(CH2COO)2N(CH2)2N(CH2COO)2)]2– (abbreviated as PbEDTA2–) Pb2+ + [C3H5O(COO)3]3– = Pb[C3H5O(COO)3] (1) Pb2+ + (CH2COO)2N(CH2)2N(CH2COO)2)4- = Pb[(CH2COO)2N(CH2)2N(CH2COO)2)]2– (2) are evaluated as 7.28 ± 0.18 (2σ) and 20.00 ± 0.20 (2σ), respectively, with a set of Pitzer parameters describing the specific interactions in NaCl and MgCl2 media. Based on these parameters, the interactions of lead with citrate and EDTA in various low temperature environments can be accurately modelled.

  19. Computational study of the interaction between a shock and a near-wall vortex using a weighted compact nonlinear scheme

    International Nuclear Information System (INIS)

    Zuo, Zhifeng; Maekawa, Hiroshi

    2014-01-01

    The interaction between a moderate-strength shock wave and a near-wall vortex is studied numerically by solving the two-dimensional, unsteady compressible Navier–Stokes equations using a weighted compact nonlinear scheme with a simple low-dissipation advection upstream splitting method for flux splitting. Our main purpose is to clarify the development of the flow field and the generation of sound waves resulting from the interaction. The effects of the vortex–wall distance on the sound generation associated with variations in the flow structures are also examined. The computational results show that three sound sources are involved in this problem: (i) a quadrupolar sound source due to the shock–vortex interaction; (ii) a dipolar sound source due to the vortex–wall interaction; and (iii) a dipolar sound source due to unsteady wall shear stress. The sound field is the combination of the sound waves produced by all three sound sources. In addition to the interaction of the incident shock with the vortex, a secondary shock–vortex interaction is caused by the reflection of the reflected shock (MR2) from the wall. The flow field is dominated by the primary and secondary shock–vortex interactions. The generation mechanism of the third sound, which is newly discovered, due to the MR2–vortex interaction is presented. The pressure variations generated by (ii) become significant with decreasing vortex–wall distance. The sound waves caused by (iii) are extremely weak compared with those caused by (i) and (ii) and are negligible in the computed sound field. (paper)

  20. Earth's magnetic field enabled scalar coupling relaxation of 13C nuclei bound to fast-relaxing quadrupolar 14N in amide groups.

    Science.gov (United States)

    Chiavazza, Enrico; Kubala, Eugen; Gringeri, Concetta V; Düwel, Stephan; Durst, Markus; Schulte, Rolf F; Menzel, Marion I

    2013-02-01

    Scalar coupling relaxation, which is usually only associated with closely resonant nuclei (e.g., (79)Br-(13)C), can be a very effective relaxation mechanism. While working on hyperpolarized [5-(13)C]glutamine, fast liquid-state polarization decay during transfer to the MRI scanner was observed. This behavior could hypothetically be explained by substantial T(1) shortening due to a scalar coupling contribution (type II) to the relaxation caused by the fast-relaxing quadrupolar (14)N adjacent to the (13)C nucleus in the amide group. This contribution is only effective in low magnetic fields (i.e., less than 800 μT) and prevents the use of molecules bearing the (13)C-amide group as hyperpolarized MRS/MRI probes. In the present work, this hypothesis is explored both theoretically and experimentally. The results show that high hyperpolarization levels can be retained using either a (15)N-labeled amide or by applying a magnetic field during transfer of the sample from the polarizer to the MRI scanner. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Attitude Strength.

    Science.gov (United States)

    Howe, Lauren C; Krosnick, Jon A

    2017-01-03

    Attitude strength has been the focus of a huge volume of research in psychology and related sciences for decades. The insights offered by this literature have tremendous value for understanding attitude functioning and structure and for the effective application of the attitude concept in applied settings. This is the first Annual Review of Psychology article on the topic, and it offers a review of theory and evidence regarding one of the most researched strength-related attitude features: attitude importance. Personal importance is attached to an attitude when the attitude is perceived to be relevant to self-interest, social identification with reference groups or reference individuals, and values. Attaching personal importance to an attitude causes crystallizing of attitudes (via enhanced resistance to change), effortful gathering and processing of relevant information, accumulation of a large store of well-organized relevant information in long-term memory, enhanced attitude extremity and accessibility, enhanced attitude impact on the regulation of interpersonal attraction, energizing of emotional reactions, and enhanced impact of attitudes on behavioral intentions and action. Thus, important attitudes are real and consequential psychological forces, and their study offers opportunities for addressing behavioral change.

  2. Inelastic transitions of atoms and molecules induced by van der Waals interaction with a surface

    International Nuclear Information System (INIS)

    Baudon, J.; Hamamda, M.; Boustimi, M.; Bocvarski, V.; Taillandier-Loize, T.; Dutier, G.; Perales, F.; Ducloy, M.

    2012-01-01

    Inelastic processes occuring in thermal-velocity metastable atoms and molecules passing at a mean distance (1–100 nm) are investigated. These processes are caused by the quadrupolar part of the van der Waals interaction: fine-structure transitions in atoms (Ar ∗ , Kr ∗ ), rovibrational transitions in N 2 ∗ ( 3 Σ u + ), transitions among magnetic sub-levels in the presence of a magnetic field.

  3. Corium crust strength measurements

    Energy Technology Data Exchange (ETDEWEB)

    Lomperski, S. [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439-4840 (United States)], E-mail: lomperski@anl.gov; Farmer, M.T. [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439-4840 (United States)], E-mail: farmer@anl.gov

    2009-11-15

    Corium strength is of interest in the context of a severe reactor accident in which molten core material melts through the reactor vessel and collects on the containment basemat. Some accident management strategies involve pouring water over the melt to solidify it and halt corium/concrete interactions. The effectiveness of this method could be influenced by the strength of the corium crust at the interface between the melt and coolant. A strong, coherent crust anchored to the containment walls could allow the yet-molten corium to fall away from the crust as it erodes the basemat, thereby thermally decoupling the melt from the coolant and sharply reducing the cooling rate. This paper presents a diverse collection of measurements of the mechanical strength of corium. The data is based on load tests of corium samples in three different contexts: (1) small blocks cut from the debris of the large-scale MACE experiments, (2) 30 cm-diameter, 75 kg ingots produced by SSWICS quench tests, and (3) high temperature crusts loaded during large-scale corium/concrete interaction (CCI) tests. In every case the corium consisted of varying proportions of UO{sub 2}, ZrO{sub 2}, and the constituents of concrete to represent a LWR melt at different stages of a molten core/concrete interaction. The collection of data was used to assess the strength and stability of an anchored, plant-scale crust. The results indicate that such a crust is likely to be too weak to support itself above the melt. It is therefore improbable that an anchored crust configuration could persist and the melt become thermally decoupled from the water layer to restrict cooling and prolong an attack of the reactor cavity concrete.

  4. Amino acid substitutions affecting aspartic acid 605 and valine 606 decrease the interaction strength between the influenza virus RNA polymerase PB2 '627' domain and the viral nucleoprotein.

    Science.gov (United States)

    Hsia, Ho-Pan; Yang, Yin-Hua; Szeto, Wun-Chung; Nilsson, Benjamin E; Lo, Chun-Yeung; Ng, Andy Ka-Leung; Fodor, Ervin; Shaw, Pang-Chui

    2018-01-01

    The influenza virus RNA genome is transcribed and replicated in the context of the viral ribonucleoprotein (vRNP) complex by the viral RNA polymerase. The nucleoprotein (NP) is the structural component of the vRNP providing a scaffold for the viral RNA. In the vRNP as well as during transcription and replication the viral polymerase interacts with NP but it is unclear which parts of the polymerase and NP mediate these interactions. Previously the C-terminal '627' domain (amino acids 538-693) of PB2 was shown to interact with NP. Here we report that a fragment encompassing amino acids 146-185 of NP is sufficient to mediate this interaction. Using NMR chemical shift perturbation assays we show that amino acid region 601 to 607 of the PB2 '627' domain interacts with this fragment of NP. Substitutions of these PB2 amino acids resulted in diminished RNP activity and surface plasmon resonance assays showed that amino acids D605 was essential for the interaction with NP and V606 may also play a partial role in the interaction. Collectively these results reveal a possible interaction surface between NP and the PB2 subunit of the RNA polymerase complex.

  5. INTERACT

    DEFF Research Database (Denmark)

    Jochum, Elizabeth; Borggreen, Gunhild; Murphey, TD

    This paper considers the impact of visual art and performance on robotics and human-computer interaction and outlines a research project that combines puppetry and live performance with robotics. Kinesics—communication through movement—is the foundation of many theatre and performance traditions ...

  6. Apparatus for rapid adjustment of the degree of alignment of NMR samples in aqueous media: verification with residual quadrupolar splittings in (23)Na and (133)Cs spectra.

    Science.gov (United States)

    Kuchel, Philip W; Chapman, Bogdan E; Müller, Norbert; Bubb, William A; Philp, David J; Torres, Allan M

    2006-06-01

    NMR spectra of (23)Na(+) and (133)Cs(+) in gelatine in a silicone rubber tube that was stretched to various extents showed remarkably reproducible resonance multiplicity. The relative intensities of the components of the split peaks had ratios, 3:4:3, and 7:12:15:16:15:12:7, respectively, that conformed with those predicted using a Mathematica program. The silicone-rubber tube was sealed at its lower end by a small rubber stopper and placed inside a thick-walled glass tube. Gelatine was injected in solution into the silicone tube and 'set' by cooling below 30 degrees C. A plastic thumb-screw held the silicone tube at various degrees of extension, up to approximately 2-fold. After constituting the gel in buffers containing NaCl and CsCl, both (23)Na and (133)Cs NMR spectroscopy revealed that after stretching the initial single Lorentzian line was split into a well-resolved triplet and a heptet, respectively. This was interpreted as being due to coupling between the electric quadrupoles of the nuclei and the average electric field gradient tensor of the collagen molecules of gelatine; these molecules became progressively more aligned in the direction of the main magnetic field, B(0), of the vertical bore magnet, as the gel was stretched. This apparatus provides a simple way of demonstrating fundamental physical characteristics of quadrupolar cations, some characteristics of gelatine under stretching, and a way to invoke static distortion of red blood cells. It should be useful with these and other cell types, for studies of metabolic and membrane transport characteristics that may change when the cells are distorted, and possibly for structural studies of macromolecules.

  7. Bond strength of masonry

    NARCIS (Netherlands)

    Pluijm, van der R.; Vermeltfoort, A.Th.

    1992-01-01

    Bond strength is not a well defined property of masonry. Normally three types of bond strength can be distinguished: - tensile bond strength, - shear (and torsional) bond strength, - flexural bond strength. In this contribution the behaviour and strength of masonry in deformation controlled uniaxial

  8. Multicenter (FXn/NH3 Halogen Bonds (X = Cl, Br and n = 1–5. QTAIM Descriptors of the Strength of the X∙∙∙N Interaction

    Directory of Open Access Journals (Sweden)

    Gabriel J. Buralli

    2017-11-01

    Full Text Available In the present work an in depth deep electronic study of multicenter XBs (FXn/NH3 (X = Cl, Br and n = 1–5 is conducted. The ways in which X∙∙∙X lateral contacts affect the electrostatic or covalent nature of the X∙∙∙N interactions are explored at the CCSD(T/aug-cc-pVTZ level and in the framework of the quantum theory of atoms in molecules (QTAIM. Calculations show that relatively strong XBs have been found with interaction energies lying between −41 and −90 kJ mol−1 for chlorine complexes, and between −56 and −113 kJ mol−1 for bromine complexes. QTAIM parameters reveal that in these complexes: (i local (kinetics and potential energy densities measure the ability that the system has to concentrate electron charge density at the intermolecular X∙∙∙N region; (ii the delocalization indices [δ(A,B] and the exchange contribution [VEX(X,N] of the interacting quantum atoms (IQA scheme, could constitute a quantitative measure of the covalence of these molecular interactions; (iii both classical electrostatic and quantum exchange show high values, indicating that strong ionic and covalent contributions are not mutually exclusive.

  9. Rock strength under explosive loading

    International Nuclear Information System (INIS)

    Rimer, N.; Proffer, W.

    1993-01-01

    This presentation emphasizes the importance of a detailed description of the nonlinear deviatoric (strength) response of the surrounding rock in the numerical simulation of underground nuclear explosion phenomenology to the late times needed for test ban monitoring applications. We will show how numerical simulations which match ground motion measurements in volcanic tuffs and in granite use the strength values obtained from laboratory measurements on small core samples of these rocks but also require much lower strength values after the ground motion has interacted with the rock. The underlying physical mechanisms for the implied strength reduction are not yet well understood, and in fact may depend on the particular rock type. However, constitutive models for shock damage and/or effective stress have been used successfully at S-Cubed in both the Geophysics Program (primarily for DARPA) and the Containment Support Program (for DNA) to simulate late time ground motions measured at NTS in many different rock types

  10. Controlling the formation process and atomic structures of single pyrazine molecular junction by tuning the strength of the metal-molecule interaction.

    Science.gov (United States)

    Kaneko, Satoshi; Takahashi, Ryoji; Fujii, Shintaro; Nishino, Tomoaki; Kiguchi, Manabu

    2017-04-12

    The formation process and atomic structures were investigated for single pyrazine molecular junctions sandwiched by three different Au, Ag, and Cu electrodes using a mechanically controllable break junction technique in ultrahigh vacuum conditions at 300 K. We demonstrated that the formation process of the single-molecule junction crucially depended on the choice of the metal electrodes. While single-molecule junction showing two distinct conductance states were found for the Au electrodes, only the single conductance state was evident for the Ag electrodes, and there was no junction formation for the Cu electrodes. These results suggested that metal-molecule interaction dominates the formation process and probability of the single-molecule junction. In addition to the metal-molecule interaction, temperature affected the formation process of the single-molecule junction. The single pyrazine molecular junction formed between Au electrodes exhibited significant temperature dependence where the junction-formation probability was about 8% at 300 K, while there was no junction-formation at 100 K. Instead of the junction formation, an Au atomic wire was formed at the low temperature. This study provides insight into the tuning of the junction-forming process for single-molecule junctions, which is needed to construct device structures on a single molecule scale.

  11. INTERACTION OF LASER RADIATION WITH MATTER: Influence of Ca and Pb impurities on the bulk optical strength of ultrapure NaCl and KCl crystals

    Science.gov (United States)

    Vinogradov, An V.; Voszka, R.; Kovalev, Valerii I.; Faĭzullov, F. S.; Janszky, J.

    1987-06-01

    A significant increase (by a factor of about 3) of the bulk damage threshold in the case of interaction of CO2 laser radiation pulses with ultrapure NaCl and KCl crystals grown in a reactive atmosphere was observed on introduction of divalent metal ions Ca and Pb in concentrations of 10-5-10-6 mol/mol. Impurities were introduced in concentrations of 10-8-10-3 and 2×10-7-10-4 mol/mol into the melts of KCl and NaCl, respectively. The concentration of other impurities (including OH) did not exceed ~10-6 mol/mol. A physical model was developed to account for the observed dependence on the basis of an analogy between a system of colloidal particles and F centers in a crystal and a liquid-vapor system.

  12. Cold molecules: formation, trapping and spectroscopy. - Piling up of cesium dimers in a quadrupolar magnetic trap. - Spectroscopy by lack of photo-association; Molecules froides: formation, piegeage et spectroscopie. - Accumulation de dimeres de cesium dans un piege quadrupolaire magnetique. - Spectroscopie par frustration de photoassociation

    Energy Technology Data Exchange (ETDEWEB)

    Vanhaecke, N

    2003-10-15

    This thesis deals with the study of cold molecules obtained through the cold atom photo-association technique. Our study is focused both on manipulating external degrees of freedom of these Cs{sub 2} molecules and on studying their internal interactions. A quadrupolar magnetic trap of about 2.10{sup 5} cold Cs{sub 2} molecules is demonstrated. The trap lifetime is on the order of 600 ms, mainly limited by the background gas pressure. The trapped molecules are identified, which allows the determination of the trapped molecule cloud temperature, which is about 35 {mu}K. A dipolar trap is set up by the use of a focused CO{sub 2} laser beam. Moreover, this thesis describes a two-photon photo-association spectroscopy. We report the first study of two-photon photo-association line shapes, which exhibit typical Fano profiles. Taking advantage of the detailed understanding of these line shapes, we measure over one hundred high-lying level energies with an accuracy on the order of 10 MHz. Then we interpret theoretically these energies. The huge hyperfine structure of the Cesium atom binds us to solve a coupled channel Schroedinger equation for internuclear distances above 15 a{sub 0}. Hence we use an asymptotic theory to fit the potential parameters of the Cs{sub 2} dimer. We adjust those parameters by the mean of both evolutionary strategies and deterministic optimum seeking. This is followed by a careful statistics study, which leads to a very accurate determination of the Vander Waals coefficient. Moreover we report the first experimental determination of the exchange interaction amplitude. (author)

  13. The Strength Compass

    DEFF Research Database (Denmark)

    Ledertoug, Mette Marie

    In the Ph.D-project ͚Strengths-based Learning - Children͛s character strengths as a means to their learning potential͛ 750 Danish children have assessed ͚The Strength Compass͛ in order to identify their strengths and to create awareness of strengths. This was followed by a strengths......-based intervention program in order to explore the strengths. Finally different methods to apply the strength in everyday life at school were applied. The paper presentation will show the results for strengths display for children aged 6-16 in different categories: Different age groups: Are the same strengths...... present in both small children and youths? Gender: Do the results show differences between the two genders? Danish as a mother- tongue language: Do the results show any differences in the strengths display when considering different language and cultural backgrounds? Children with Special Needs: Do...

  14. Influence of magnetoelastic coupling on the phase transitions in two-dimensional non-Heisenberg magnetics with biquadratic interaction

    International Nuclear Information System (INIS)

    Fridman, Yu.A.; Klevets, Ph.N.; Kozhemyako, O.V.

    2003-01-01

    Influence of magnetoelastic (ME) interaction on the phase transitions in two-dimensional non-Heisenberg ferromagnets is investigated. It is shown that if the constant of Heisenberg exchange interaction is large, the ferromagnetic phase is implemented in a system. When the value of biquadratic exchange interaction increases there is a phase transition to the quadrupolar phase characterized by the tensor order parameters. Thus, ME interaction plays an essential role, not only stabilizing the long-range magnetic order in the system, but also determining the order of the phase transition

  15. The strength compass

    DEFF Research Database (Denmark)

    Ledertoug, Mette Marie

    of agreement/disagreement. Also the child/teacher is asked whether the actual strength is important and if he or she has the possibilities to apply the strength in the school. In a PhDproject ‘Strengths-based Learning - Children’s Character Strengths as Means to their Learning Potential’ 750 Danish children......Individual paper presentation: The ‘Strength Compass’. The results of a PhDresearch project among schoolchildren (age 6-16) identifying VIAstrengths concerning age, gender, mother-tongue-langue and possible child psychiatric diagnosis. Strengths-based interventions in schools have a theoretical...... Psychological Publishing Company. ‘The Strength Compass’ is a computer/Ipad based qualitative tool to identify the strengths of a child by a self-survey or a teacher’s survey. It is designed as a visual analogue scale with a statement of the strength in which the child/teacher may declare the degree...

  16. Electronic properties of quasi one-dimensional quantum wire models under equal coupling strength superpositions of Rashba and Dresselhaus spin-orbit interactions in the presence of an in-plane magnetic field

    International Nuclear Information System (INIS)

    Papp, E.; Micu, C.; Racolta, D.

    2013-01-01

    In this paper one deals with the theoretical derivation of energy bands and of related wavefunctions characterizing quasi 1D semiconductor heterostructures, such as InAs quantum wire models. Such models get characterized this time by equal coupling strength superpositions of Rashba and Dresselhaus spin-orbit interactions of dimensionless magnitude a under the influence of in-plane magnetic fields of magnitude B. We found that the orientations of the field can be selected by virtue of symmetry requirements. For this purpose one resorts to spin conservations, but alternative conditions providing sensible simplifications of the energy-band formula can be reasonably accounted for. Besides the wavenumber k relying on the 1D electron, one deals with the spin-like s=±1 factors in the front of the square root term of the energy. Having obtained the spinorial wavefunction, opens the way to the derivation of spin precession effects. For this purpose one resorts to the projections of the wavenumber operator on complementary spin states. Such projections are responsible for related displacements proceeding along the Ox-axis. This results in a 2D rotation matrix providing both the precession angle as well as the precession axis

  17. Strengths-based Learning

    DEFF Research Database (Denmark)

    Ledertoug, Mette Marie

    -being. The Ph.D.-project in Strength-based learning took place in a Danish school with 750 pupils age 6-16 and a similar school was functioning as a control group. The presentation will focus on both the aware-explore-apply processes and the practical implications for the schools involved, and on measurable......Strength-based learning - Children͛s Character Strengths as Means to their Learning Potential͛ is a Ph.D.-project aiming to create a strength-based mindset in school settings and at the same time introducing strength-based interventions as specific tools to improve both learning and well...

  18. Give Me Strength.

    Institute of Scientific and Technical Information of China (English)

    维拉

    1996-01-01

    Mort had an absolutely terrible day at the office.Everythingthat could go wrong did go wrong.As he walked home he could beheard muttering strange words to himself:“Oh,give me strength,give me strength.”Mort isn’t asking for the kind of strength thatbuilds strong muscles:he’s asking for the courage or ability to

  19. Low-frequency nuclear quadrupole resonance with a dc SQUID

    International Nuclear Information System (INIS)

    Chang, J.W.

    1991-07-01

    Conventional pure nuclear quadrupole resonance (NQR) is a technique well suited for the study of very large quadrupolar interactions. Numerous nuclear magnetic resonance (NMR) techniques have been developed for the study of smaller quadrupolar interactions. However, there are many nuclei which have quadrupolar interactions of intermediate strength. Quadrupolar interactions in this region have traditionally been difficult or unfeasible to detect. This work describes the development and application of a SQUID NQR technique which is capable of measuring intermediate strength quadrupolar interactions, in the range of a few hundred kilohertz to several megahertz. In this technique, a dc SQUID (Superconducting QUantum Interference Device) is used to monitor the longitudinal sample magnetization, as opposed to the transverse magnetization, as a rf field is swept in frequency. This allows the detection of low-frequency nuclear quadrupole resonances over a very wide frequency range with high sensitivity. The theory of this NQR technique is discussed and a description of the dc SQUID system is given. In the following chapters, the spectrometer is discussed along with its application to the study of samples containing half-odd-integer spin quadrupolar nuclei, in particular boron-11 and aluminum-27. The feasibility of applying this NQR technique in the study of samples containing integer spin nuclei is discussed in the last chapter. 140 refs., 46 figs., 6 tabs

  20. Institutional Strength in Depth

    International Nuclear Information System (INIS)

    Weightman, M.

    2016-01-01

    Much work has been undertaken in order to identify, learn and implement the lessons from the TEPCO Fukushima Daiichi nuclear accident. These have mainly targeted on engineering or operational lessons. Less attention has been paid to the institutional lessons, although there have been some measures to improve individual peer reviews, particularly by the World Association of Nuclear Operators, and the authoritative IAEA report published in 2015 brought forward several important lessons for regulators and advocated a system approach. The report noted that one of the contributing factors the accident was the tendency of stakeholders not to challenge. Additionally, it reported deficiencies in the regulatory authority and system. Earlier, the root cause of the accident was identified by a Japanese independent parliamentary report as being cultural and institutional. The sum total of the institutions, the safety system, was ineffective. While it is important to address the many technical and operational lessons these may not necessary address this more fundamental lesson, and may not serve to provide robust defences against human or institutional failings over a wide variety of possible events and combinations. The overall lesson is that we can have rigorous and comprehensive safety standards and other tools in place to deliver high levels of safety, but ultimately what is important is the ability of the nuclear safety system to ensure that the relevant institutions diligently and effectively apply those standards and tools — to be robust and resilient. This has led to the consideration of applying the principles of the strength in depth philosophy to a nuclear safety system as a way of providing a framework for developing, assessing, reviewing and improving the system. At an IAEA conference in October 2013, a model was presented for a robust national nuclear safety system based on strength in depth philosophy. The model highlighted three main layers: industry, the

  1. Anisotropic Concrete Compressive Strength

    DEFF Research Database (Denmark)

    Gustenhoff Hansen, Søren; Jørgensen, Henrik Brøner; Hoang, Linh Cao

    2017-01-01

    When the load carrying capacity of existing concrete structures is (re-)assessed it is often based on compressive strength of cores drilled out from the structure. Existing studies show that the core compressive strength is anisotropic; i.e. it depends on whether the cores are drilled parallel...

  2. High strength ferritic alloy

    International Nuclear Information System (INIS)

    1977-01-01

    A high strength ferritic steel is specified in which the major alloying elements are chromium and molybdenum, with smaller quantities of niobium, vanadium, silicon, manganese and carbon. The maximum swelling is specified for various irradiation conditions. Rupture strength is also specified. (U.K.)

  3. Photon strength functions

    International Nuclear Information System (INIS)

    Bergqvist, I.

    1976-01-01

    Methods for extracting photon strength functions are briefly discussed. We follow the Brink-Axel approach to relate the strength functions to the giant resonances observed in photonuclear work and summarize the available data on the E1, E2 and M1 resonances. Some experimental and theoretical problems are outlined. (author)

  4. Interviewing to Understand Strengths

    Science.gov (United States)

    Hass, Michael R.

    2018-01-01

    Interviewing clients about their strengths is an important part of developing a complete understanding of their lives and has several advantages over simply focusing on problems and pathology. Prerequisites for skillfully interviewing for strengths include the communication skills that emerge from a stance of not knowing, developing a vocabulary…

  5. Detection of rock strength at Branisko massif

    Directory of Open Access Journals (Sweden)

    Lazarová Edita

    2000-09-01

    Full Text Available When monitoring and optimizing the driving proces of the exploratory gallery by a computer system, conditions for verification of the interaction between desintegrating head of driving machine and rock massif were created. One of the output values of this mathematical model is the model strength at a simple pressure ótlH, which is defined as a pressure at the discus and the massif contact during the desintigration (a near limit of massif strength. By geological and geological engineering exploration, the section of length 2340 m was divided into fourty-two geological sections and five quasi-homogeneous massif enviroments. In the article, results of scleroscopic strength óCI , the strength in a simple pressure determined from the point load test and the strength at simple pressure ótlH are confronted . The main advance of the electronic geomechanical monitoring is the density of gained information. The two-seconds sample period of input and output data during the driving process makes it possible to describe driving circumstances in an almost continual way for each millimeter of the built tunnel. Then the information about changes of disintegrated rock properties, have the same density (frequency. By comparing a quantity of data gained by examining the index of point strength, scleroscopic strength and the model strength in a simple pressure from the monitoring process of driving process it is obvious that during the driving of exploratory gallery of motorway tunnel Branisko, a proportion of data number from the three “type examinations” of strength was reached and it was approximately 1:7:5000. Approximately in the same proportion, there were determined values for the 42 geologic sections (I. – XLII., which were defined in detail by the geologic, engineering geologic, hydrogeologic and geotechnic research.. The presented quantity values of presented rock mass strength for each geologic section are presented by their arithmetic average

  6. Argument Strength and the Persuasiveness of Stories

    Science.gov (United States)

    Schreiner, Constanze; Appel, Markus; Isberner, Maj-Britt; Richter, Tobias

    2017-01-01

    ABSTRACT Stories are a powerful means to change people’s attitudes and beliefs. The aim of the current work was to shed light on the role of argument strength (argument quality) in narrative persuasion. The present study examined the influence of strong versus weak arguments on attitudes in a low or high narrative context. Moreover, baseline attitudes, interindividual differences in working memory capacity, and recipients’ transportation were examined. Stories with strong arguments were more persuasive than stories with weak arguments. This main effect was qualified by a two-way interaction with baseline attitude, revealing that argument strength had a greater impact on individuals who initially were particularly doubtful toward the story claim. Furthermore, we identified a three-way interaction showing that argument strength mattered most for recipients who were deeply transported into the story world in stories that followed a typical narrative structure. These findings provide an important specification of narrative persuasion theory. PMID:29805322

  7. Strength of Fibrous Composites

    CERN Document Server

    Huang, Zheng-Ming

    2012-01-01

    "Strength of Fibrous Composites" addresses evaluation of the strength of a fibrous composite by using its constituent material properties and its fiber architecture parameters. Having gone through the book, a reader is able to predict the progressive failure behavior and ultimate strength of a fibrous laminate subjected to an arbitrary load condition in terms of the constituent fiber and matrix properties, as well as fiber geometric parameters. The book is useful to researchers and engineers working on design and analysis for composite materials. Dr. Zheng-Ming Huang is a professor at the School of Aerospace Engineering & Applied Mechanics, Tongji University, China. Mr. Ye-Xin Zhou is a PhD candidate at the Department of Mechanical Engineering, the University of Hong Kong, China.

  8. High strength alloys

    Science.gov (United States)

    Maziasz, Phillip James [Oak Ridge, TN; Shingledecker, John Paul [Knoxville, TN; Santella, Michael Leonard [Knoxville, TN; Schneibel, Joachim Hugo [Knoxville, TN; Sikka, Vinod Kumar [Oak Ridge, TN; Vinegar, Harold J [Bellaire, TX; John, Randy Carl [Houston, TX; Kim, Dong Sub [Sugar Land, TX

    2010-08-31

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tubular that is at least partially made from a material containing at least one of the metal alloys.

  9. Hand grip strength

    DEFF Research Database (Denmark)

    Frederiksen, Henrik; Gaist, David; Petersen, Hans Christian

    2002-01-01

    in life is a major problem in terms of prevalence, morbidity, functional limitations, and quality of life. It is therefore of interest to find a phenotype reflecting physical functioning which has a relatively high heritability and which can be measured in large samples. Hand grip strength is known......-55%). A powerful design to detect genes associated with a phenotype is obtained using the extreme discordant and concordant sib pairs, of whom 28 and 77 dizygotic twin pairs, respectively, were found in this study. Hence grip strength is a suitable phenotype for identifying genetic variants of importance to mid...

  10. Probe tests microweld strength

    Science.gov (United States)

    1965-01-01

    Probe is developed to test strength of soldered, brazed or microwelded joints. It consists of a spring which may be adjusted to the desired test pressure by means of a threaded probe head, and an indicator lamp. Device may be used for electronic equipment testing.

  11. Optimal estimation of the optomechanical coupling strength

    Science.gov (United States)

    Bernád, József Zsolt; Sanavio, Claudio; Xuereb, André

    2018-06-01

    We apply the formalism of quantum estimation theory to obtain information about the value of the nonlinear optomechanical coupling strength. In particular, we discuss the minimum mean-square error estimator and a quantum Cramér-Rao-type inequality for the estimation of the coupling strength. Our estimation strategy reveals some cases where quantum statistical inference is inconclusive and merely results in the reinforcement of prior expectations. We show that these situations also involve the highest expected information losses. We demonstrate that interaction times on the order of one time period of mechanical oscillations are the most suitable for our estimation scenario, and compare situations involving different photon and phonon excitations.

  12. Redox Buffer Strength

    Science.gov (United States)

    de Levie, Robert

    1999-04-01

    The proper functioning of enzymes in bodily fluids requires that the pH be maintained within rather narrow limits. The first line of defense against large pH fluctuations in such fluids is the passive control provided by the presence of pH buffers. The ability of pH buffers to stabilize the pH is indicated by the buffer value b introduced in 1922 by van Slyke. It is equally important for many enzymes that the redox potential is kept within a narrow range. In that case, stability of the potential is most readily achieved with a redox buffer. In this communication we define the redox buffer strength by analogy with acid-base buffer strength.

  13. Strength capability while kneeling.

    Science.gov (United States)

    Haslegrave, C M; Tracy, M F; Corlett, E N

    1997-12-01

    Work sometimes has to be carried out kneeling, particularly where jobs are performed in confined spaces as is common for miners, aircraft baggage handlers and maintenance workers. In order to assess the risks in performing forceful tasks under such conditions, data is needed on strength capabilities of kneeling subjects. A study was undertaken to measure isometric strength in single-handed exertions for male subjects and to investigate the effects on this of task layout factors (direction of force exertion, reach distance, height of the workpiece and orientation relative to the subject's sagittal plane). The data has been tabulated to show the degree to which strength may be reduced in different situations and analysis of the task factors showed their influence to be complex with direction of exertion and reach distance having the greatest effect. The results also suggest that exertions are weaker when subjects are kneeling on two knees than when kneeling on one knee, although this needs to be confirmed by direct experimental comparison.

  14. Inferring tie strength from online directed behavior.

    Directory of Open Access Journals (Sweden)

    Jason J Jones

    Full Text Available Some social connections are stronger than others. People have not only friends, but also best friends. Social scientists have long recognized this characteristic of social connections and researchers frequently use the term tie strength to refer to this concept. We used online interaction data (specifically, Facebook interactions to successfully identify real-world strong ties. Ground truth was established by asking users themselves to name their closest friends in real life. We found the frequency of online interaction was diagnostic of strong ties, and interaction frequency was much more useful diagnostically than were attributes of the user or the user's friends. More private communications (messages were not necessarily more informative than public communications (comments, wall posts, and other interactions.

  15. Cavity-photon contribution to the effective interaction of electrons in parallel quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Gudmundsson, Vidar [Science Institute, University of Iceland, Reykjavik (Iceland); Sitek, Anna [Science Institute, University of Iceland, Reykjavik (Iceland); Department of Theoretical Physics, Faculty of Fundamental Problems of Technology, Wroclaw University of Technology (Poland); Abdullah, Nzar Rauf [Science Institute, University of Iceland, Reykjavik (Iceland); Physics Department, Faculty of Science and Science Education, School of Science, University of Sulaimani, Kurdistan Region (Iraq); Tang, Chi-Shung [Department of Mechanical Engineering, National United University, Miaoli (China); Manolescu, Andrei [School of Science and Engineering, Reykjavik University (Iceland)

    2016-05-15

    A single cavity photon mode is expected to modify the Coulomb interaction of an electron system in the cavity. Here we investigate this phenomena in a parallel double quantum dot system. We explore properties of the closed system and the system after it has been opened up for electron transport. We show how results for both cases support the idea that the effective electron-electron interaction becomes more repulsive in the presence of a cavity photon field. This can be understood in terms of the cavity photons dressing the polarization terms in the effective mutual electron interaction leading to nontrivial delocalization or polarization of the charge in the double parallel dot potential. In addition, we find that the effective repulsion of the electrons can be reduced by quadrupolar collective oscillations excited by an external classical dipole electric field. (copyright 2015 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Cavity-photon contribution to the effective interaction of electrons in parallel quantum dots

    Science.gov (United States)

    Gudmundsson, Vidar; Sitek, Anna; Abdullah, Nzar Rauf; Tang, Chi-Shung; Manolescu, Andrei

    2016-05-01

    A single cavity photon mode is expected to modify the Coulomb interaction of an electron system in the cavity. Here we investigate this phenomena in a parallel double quantum dot system. We explore properties of the closed system and the system after it has been opened up for electron transport. We show how results for both cases support the idea that the effective electron-electron interaction becomes more repulsive in the presence of a cavity photon field. This can be understood in terms of the cavity photons dressing the polarization terms in the effective mutual electron interaction leading to nontrivial delocalization or polarization of the charge in the double parallel dot potential. In addition, we find that the effective repulsion of the electrons can be reduced by quadrupolar collective oscillations excited by an external classical dipole electric field.

  17. Strengths only or strengths and relative weaknesses? A preliminary study.

    Science.gov (United States)

    Rust, Teri; Diessner, Rhett; Reade, Lindsay

    2009-10-01

    Does working on developing character strengths and relative character weaknesses cause lower life satisfaction than working on developing character strengths only? The present study provides a preliminary answer. After 76 college students completed the Values in Action Inventory of Strengths (C. Peterson & M. E. P. Seligman, 2004), the authors randomly assigned them to work on 2 character strengths or on 1 character strength and 1 relative weakness. Combined, these groups showed significant gains on the Satisfaction With Life Scale (E. Diener, R. A. Emmons, R. J. Larsen, & S. Griffin, 1985), compared with a 32-student no-treatment group. However, there was no significant difference in gain scores between the 2-strengths group and the 1-character-strength-and-1-relative-character-weakness group. The authors discuss how focusing on relative character weaknesses (along with strengths) does not diminish-and may assist in increasing-life satisfaction.

  18. Perturbation theory for arbitrary coupling strength?

    Science.gov (United States)

    Mahapatra, Bimal P.; Pradhan, Noubihary

    2018-03-01

    We present a new formulation of perturbation theory for quantum systems, designated here as: “mean field perturbation theory” (MFPT), which is free from power-series-expansion in any physical parameter, including the coupling strength. Its application is thereby extended to deal with interactions of arbitrary strength and to compute system-properties having non-analytic dependence on the coupling, thus overcoming the primary limitations of the “standard formulation of perturbation theory” (SFPT). MFPT is defined by developing perturbation about a chosen input Hamiltonian, which is exactly solvable but which acquires the nonlinearity and the analytic structure (in the coupling strength) of the original interaction through a self-consistent, feedback mechanism. We demonstrate Borel-summability of MFPT for the case of the quartic- and sextic-anharmonic oscillators and the quartic double-well oscillator (QDWO) by obtaining uniformly accurate results for the ground state of the above systems for arbitrary physical values of the coupling strength. The results obtained for the QDWO may be of particular significance since “renormalon”-free, unambiguous results are achieved for its spectrum in contrast to the well-known failure of SFPT in this case.

  19. Strength Training Following Hematopoietic Stem Cell Transplantation

    Science.gov (United States)

    Hacker, Eileen Danaher; Larson, Janet; Kujath, Amber; Peace, David; Rondelli, Damiano; Gaston, Lisa

    2010-01-01

    Background Patients receiving high-dose chemotherapy and hematopoietic stem cell transplantation (HSCT) experience considerable reductions in physical activity and deterioration of their health status. Objective The purpose of this pilot study was to test the effects of strength training compared to usual activity on physical activity, muscle strength, fatigue, health status perceptions, and quality of life following HSCT. Interventions/Methods Nineteen subjects were randomized to the exercise or control group. Moderate intensity strength training began following discharge from the hospital. Dependent variables included physical activity, muscle strength, fatigue, health status perceptions and quality of life. Variables were measured prior to admission to the hospital for HSCT, day 8 following HSCT, and six weeks following discharge from the hospital. Results Significant time effects were noted for many variables with anticipated declines in physical activity, muscle strength, fatigue, and health status perceptions immediately after HSCT with subsequent improvements six weeks following hospital discharge. One group effect was noted with subjects in the exercise group reporting less fatigue than subjects in the control group. Although no significant interactions were detected, the trends suggest that the exercise group may be more physically active following the intervention compared to the usual activity group. Conclusions This study demonstrates the potential positive effects of strength training on physical activity, fatigue, and quality of life in people receiving high-dose chemotherapy and HSCT. Implications for Practice Preliminary evidence is provided for using strength training to enhance early recovery following HSCT. Elastic resistance bands are easy to use and relatively inexpensive. PMID:21116175

  20. Strength Training: For Overall Fitness

    Science.gov (United States)

    Healthy Lifestyle Fitness Strength training is an important part of an overall fitness program. Here's what strength training can do for ... is a key component of overall health and fitness for everyone. Lean muscle mass naturally diminishes with ...

  1. Direct measurement of the interaction energy between solids and gases--3. Comparison of the calorimetric titration method with the amine titration method for the determination of acid strength distribution of the silica-alumina surface

    Energy Technology Data Exchange (ETDEWEB)

    Taniguchi, H.; Masuda, T.; Tsutsumi, K.; Takahashi, H.

    1978-07-01

    Comparison of the calorimetric titration method with the amine titration method for the determination of acid strength distribution of the silica-alumina surface was carried out for a catalyst containing 13% by wt alumina and evacuated at 400/sup 0/C at 0.00001 mm Hg for five hours. The heats of adsorption of ammonia on silica-alumina poisoned with Hammett indicators of 8.2 to 3.3 pK/sub a/ were also measured to obtain the relation between the dissociation constant of the acid (pK/sub a/) and the heat of adsorption. At pK/sub a/ values of -5.6 and +3.3, the differential heats of adsorption were 76.1 and 55.1 kj/mole, respectively. The number of acid sites calculated from the heat vs. adsorbed-amount curve was about twice as large as that determined by amine titration. The discrepancy is discussed.

  2. Nuclear beta decay and the weak interaction

    International Nuclear Information System (INIS)

    Kean, D.C.

    1975-11-01

    Short notes are presented on various aspects of nuclear beta decay and weak interactions including: super-allowed transitions, parity violation, interaction strengths, coupling constants, and the current-current formalism of weak interaction. (R.L.)

  3. Gaussian discriminating strength

    Science.gov (United States)

    Rigovacca, L.; Farace, A.; De Pasquale, A.; Giovannetti, V.

    2015-10-01

    We present a quantifier of nonclassical correlations for bipartite, multimode Gaussian states. It is derived from the Discriminating Strength measure, introduced for finite dimensional systems in Farace et al., [New J. Phys. 16, 073010 (2014), 10.1088/1367-2630/16/7/073010]. As the latter the new measure exploits the quantum Chernoff bound to gauge the susceptibility of the composite system with respect to local perturbations induced by unitary gates extracted from a suitable set of allowed transformations (the latter being identified by posing some general requirements). Closed expressions are provided for the case of two-mode Gaussian states obtained by squeezing or by linearly mixing via a beam splitter a factorized two-mode thermal state. For these density matrices, we study how nonclassical correlations are related with the entanglement present in the system and with its total photon number.

  4. Compressive and flexural strength of high strength phase change mortar

    Science.gov (United States)

    Qiao, Qingyao; Fang, Changle

    2018-04-01

    High-strength cement produces a lot of hydration heat when hydrated, it will usually lead to thermal cracks. Phase change materials (PCM) are very potential thermal storage materials. Utilize PCM can help reduce the hydration heat. Research shows that apply suitable amount of PCM has a significant effect on improving the compressive strength of cement mortar, and can also improve the flexural strength to some extent.

  5. Strength of Gamma Rhythm Depends on Normalization

    Science.gov (United States)

    Ray, Supratim; Ni, Amy M.; Maunsell, John H. R.

    2013-01-01

    Neuronal assemblies often exhibit stimulus-induced rhythmic activity in the gamma range (30–80 Hz), whose magnitude depends on the attentional load. This has led to the suggestion that gamma rhythms form dynamic communication channels across cortical areas processing the features of behaviorally relevant stimuli. Recently, attention has been linked to a normalization mechanism, in which the response of a neuron is suppressed (normalized) by the overall activity of a large pool of neighboring neurons. In this model, attention increases the excitatory drive received by the neuron, which in turn also increases the strength of normalization, thereby changing the balance of excitation and inhibition. Recent studies have shown that gamma power also depends on such excitatory–inhibitory interactions. Could modulation in gamma power during an attention task be a reflection of the changes in the underlying excitation–inhibition interactions? By manipulating the normalization strength independent of attentional load in macaque monkeys, we show that gamma power increases with increasing normalization, even when the attentional load is fixed. Further, manipulations of attention that increase normalization increase gamma power, even when they decrease the firing rate. Thus, gamma rhythms could be a reflection of changes in the relative strengths of excitation and normalization rather than playing a functional role in communication or control. PMID:23393427

  6. Influence of the mechanical properties of lime mortar on the strength of brick masonry

    OpenAIRE

    PAVIA, SARA

    2013-01-01

    PUBLISHED This paper aims at improving the quality of lime mortar masonry by understanding the mechanics of mortars and masonry and their interaction. It investigates how the mortar?s compressive and flexural strengths impact the compressive and bond strength of clay brick masonry bound with calcium lime (CL) and natural hydraulic lime (NHL) mortars. It concludes that the strength of the bond has a greater impact on the compressive strength of masonry than the mortar?s st...

  7. Loading Conditions and Longitudinal Strength

    DEFF Research Database (Denmark)

    Sørensen, Herman

    1995-01-01

    Methods for the calculation of the lightweight of the ship.Loading conditions satisfying draught, trim and intact stability requirements and analysis of the corresponding stillwater longitudinal strength.......Methods for the calculation of the lightweight of the ship.Loading conditions satisfying draught, trim and intact stability requirements and analysis of the corresponding stillwater longitudinal strength....

  8. Oscillator strengths for neutral technetium

    International Nuclear Information System (INIS)

    Garstang, R.H.

    1981-01-01

    Oscillator strengths have been calculated for most of the spectral lines of TcI which are of interest in the study of stars of spectral type S. Oscillator strengths have been computed for the corresponding transitions in MnI as a partial check of the technetium calculations

  9. Strength in numbers

    DEFF Research Database (Denmark)

    Simonsen, Karina T; Gallego, Sandra F; Færgeman, Nils J.

    2012-01-01

    alterations on the transcriptional and translational levels. Early on, researchers took advantage of the possibility to conduct large-scale investigations of the C. elegans immune response. Multiple studies demonstrated that C. elegans does indeed mount a protective response against invading pathogens, thus...... rendering this small nematode a very useful and simple host model for the study of innate immunity and host-pathogen interactions. Here, we provide an overview of key aspects of innate immunity in C. elegans revealed by recent whole-genome transcriptomics and proteomics studies of the global response of C......For more than ten years the nematode Caenorhabditis elegans has proven to be a valuable model for studies of the host response to various bacterial and fungal pathogens. When exposed to a pathogenic organism, a clear response is elicited in the nematode, which is characterized by specific...

  10. Influence of adhesion promoters and curing-light sources on the shear bond strength of orthodontic brackets

    Directory of Open Access Journals (Sweden)

    Claudia Tavares Machado

    2012-01-01

    Conclusions: The conventional orthodontic adhesive presented higher bond strength than the nanofilled composite, although both materials interacted similarly to the teeth. The curing-light devices tested did not influence on bond strength of orthodontic brackets.

  11. STRENGTH OF NANOMODIFIED HIGH-STRENGTH LIGHTWEIGHT CONCRETES

    Directory of Open Access Journals (Sweden)

    NOZEMTСEV Alexandr Sergeevich

    2013-02-01

    Full Text Available The paper presents the results of research aimed at development of nanomodified high-strength lightweight concrete for construction. The developed concretes are of low average density and high ultimate compressive strength. It is shown that to produce this type of concrete one need to use hollow glass and aluminosilicate microspheres. To increase the durability of adhesion between cement stone and fine filler the authors offer to use complex nanodimensinal modifier based on iron hydroxide sol and silica sol as a surface nanomodifier for hollow microspheres. It is hypothesized that the proposed modifier has complex effect on the activity of the cement hydration and, at the same time increases bond strength between filler and cement-mineral matrix. The compositions for energy-efficient nanomodified high-strength lightweight concrete which density is 1300…1500 kg/m³ and compressive strength is 40…65 MPa have been developed. The approaches to the design of high-strength lightweight concrete with density of less than 2000 kg/m³ are formulated. It is noted that the proposed concretes possess dense homogeneous structure and moderate mobility. Thus, they allow processing by vibration during production. The economic and practical implications for realization of high-strength lightweight concrete in industrial production have been justified.

  12. Third order dielectric susceptibility in a model quantum paraelectric

    International Nuclear Information System (INIS)

    Martonak, R.; Tosatti, E.

    1996-02-01

    In the context of perovskite quantum paraelectrics, we study the effects of a quadrupolar interaction J q , in addition to the standard dipolar one J d . We concentrate here on the nonlinear dielectric response χ (3) P , as the main response function sensitive to quadrupolar (in our case antiquadrupolar) interactions. We employ a 3D quantum four-state lattice model and mean-field theory. The results show that inclusion of quadrupolar coupling of moderate strength (J q ∼ 1/4J d ) is clearly accompanied by a double change of sign of χ (3) P from negative to positive, near the quantum temperature T Q where the quantum paraelectric behaviour sets in. We fit our χ (3) to recent experimental data for SrTiO 3 , where the sign change is identified close to T Q ∼ 37 K. (author). 40 refs, 2 figs

  13. Strength Training and Your Child

    Science.gov (United States)

    ... in organized sports or activities such as baseball, soccer, or gymnastics usually can safely to start strength ... as biking and running, adequate hydration, and healthy nutrition. Reviewed by: Mary L. Gavin, MD Date reviewed: ...

  14. Characteristics of structural loess strength and preliminary framework for joint strength formula

    OpenAIRE

    Rong-jian Li; Jun-ding Liu; Rui Yan; Wen Zheng; Sheng-jun Shao

    2014-01-01

    The strength of structural loess consists of the shear strength and tensile strength. In this study, the stress path, the failure envelope of principal stress (Kf line), and the strength failure envelope of structurally intact loess and remolded loess were analyzed through three kinds of tests: the tensile strength test, the uniaxial compressive strength test, and the conventional triaxial shear strength test. Then, in order to describe the tensile strength and shear strength of structural lo...

  15. AND EXPLOSIVE STRENGTH OF YOUNG GYMNASTS

    Directory of Open Access Journals (Sweden)

    G. Dallas

    2014-08-01

    Full Text Available The purpose of this study was to examine the acute effect of a single bout of whole body vibration (WBV on flexibility and explosive strength of lower limbs in young artistic gymnasts. Thirty-two young competitive gymnasts volunteered to participate in this study, and were allocated to either the vibration group or traditional body weight training according to the vibration protocol. The vibration intervention consisted of a single bout of eccentric and concentric squatting movements on a vibration platform that was turned on (vibration group: VG n=15, whereas the traditional body weight (no vibration group performed the same training protocol with the WBV device turned off (NVG: n= 17. Flexibility (sit and reach test and explosive strength tests [squat jump (SJ, counter movement jump (CMJ, and single leg squat (right leg (RL and left leg (LL] were performed initially (pre-test, immediately after the intervention (post-test 1, and 15 minutes after the end of the intervention programme (post-test 15. Four 2x3 ANOVAs were used to examine the interaction between group (VG vs NVG and time (pre, post 1, and post 15 with respect to examined variables. The results revealed that a significant interaction between group and time was found with respect to SJ (p 0.05. Further, the percentage improvement of the VG was significantly greater in all examined variables compared to the NVG. This study concluded that WBV training improves flexibility and explosive strength of lower limbs in young trained artistic gymnasts and maintains the initial level of performance for at least 15 minutes after the WBV intervention programme.

  16. Tree-grass interactions in savannas

    CSIR Research Space (South Africa)

    Scholes, RJ

    1997-01-01

    Full Text Available Savannas occur where trees and grasses interact to create a biome that is neither grassland nor forest. Woody and gramineous plants interact by many mechanisms, some negative (competition) and some positive (facilitation). The strength and sign...

  17. Penetrator strength effect in long-rod critical ricochet angle

    International Nuclear Information System (INIS)

    Daneshjou, K.; Shahravi, M.

    2008-01-01

    3D numerical simulations were performed in order to further investigate the role of penetrator strength in the interaction of long-rods and oblique targets. Three distinctive regimes resulting from oblique impact depending on the obliquity, namely simple ricochet, critical ricochet and target perforation, were investigated in detail. Critical ricochet angles were calculated with a full 3D explicit finite element method for various impact velocities and strength of target plates and projectiles. Numerical predictions were compared with existing two-dimensional analytical models and test results. It was predicted that critical ricochet angle increases with decreasing impact velocity and that higher ricochet angles were expected if higher strength target materials are employed. But there are differences between analytical models and 3D numerical simulation results or test results. The causes for these discrepancies are established by numerical simulations which explore the validity of the penetrator strength parameter in the analytical model as a physical entity. As a matter of fact, in this paper we first investigate the role of penetrator dynamic strength using two-dimensional simulation which resulted in different penetrator strengths out of different impact velocities. Next, by applying these amounts for penetrator strength in Rosenberg analytical model the critical ricochet angle is calculated. Finally, a comparison between the present analytical method with the 3D simulation and test results shows that the new analytical approach leads to modified results with respect to Rosenberg ones

  18. Interfacial Shear Strength and Adhesive Behavior of Silk Ionomer Surfaces.

    Science.gov (United States)

    Kim, Sunghan; Geryak, Ren D; Zhang, Shuaidi; Ma, Ruilong; Calabrese, Rossella; Kaplan, David L; Tsukruk, Vladimir V

    2017-09-11

    The interfacial shear strength between different layers in multilayered structures of layer-by-layer (LbL) microcapsules is a crucial mechanical property to ensure their robustness. In this work, we investigated the interfacial shear strength of modified silk fibroin ionomers utilized in LbL shells, an ionic-cationic pair with complementary ionic pairing, (SF)-poly-l-glutamic acid (Glu) and SF-poly-l-lysine (Lys), and a complementary pair with partially screened Coulombic interactions due to the presence of poly(ethylene glycol) (PEG) segments and SF-Glu/SF-Lys[PEG] pair. Shearing and adhesive behavior between these silk ionomer surfaces in the swollen state were probed at different spatial scales and pressure ranges by using functionalized atomic force microscopy (AFM) tips as well as functionalized colloidal probes. The results show that both approaches were consistent in analyzing the interfacial shear strength of LbL silk ionomers at different spatial scales from a nanoscale to a fraction of a micron. Surprisingly, the interfacial shear strength between SF-Glu and SF-Lys[PEG] pair with partially screened ionic pairing was greater than the interfacial shear strength of the SF-Glu and SF-Lys pair with a high density of complementary ionic groups. The difference in interfacial shear strength and adhesive strength is suggested to be predominantly facilitated by the interlayer hydrogen bonding of complementary amino acids and overlap of highly swollen PEG segments.

  19. Reactive Strength Index: A Poor Indicator of Reactive Strength?

    Science.gov (United States)

    Healy, Robin; Kenny, Ian; Harrison, Drew

    2017-11-28

    The primary aim was to assess the relationships between reactive strength measures and associated kinematic and kinetic performance variables achieved during drop jumps. A secondary aim was to highlight issues with the use of reactive strength measures as performance indicators. Twenty eight national and international level sprinters, consisting of fourteen men and women, participated in this cross-sectional analysis. Athletes performed drop jumps from a 0.3 m box onto a force platform with dependent variables contact time (CT), landing time (TLand), push-off time (TPush), flight time (FT), jump height (JH), reactive strength index (RSI, calculated as JH / CT), reactive strength ratio (RSR, calculated as FT / CT) and vertical leg spring stiffness (Kvert) recorded. Pearson's correlation test found very high to near perfect relationships between RSI and RSR (r = 0.91 to 0.97), with mixed relationships found between RSI, RSR and the key performance variables, (Men: r = -0.86 to -0.71 between RSI/RSR and CT, r = 0.80 to 0.92 between RSI/RSR and JH; Women: r = -0.85 to -0.56 between RSR and CT, r = 0.71 between RSI and JH). This study demonstrates that the method of assessing reactive strength (RSI versus RSR) may be influenced by the performance strategies adopted i.e. whether an athlete achieves their best reactive strength scores via low CTs, high JHs or a combination. Coaches are advised to limit the variability in performance strategies by implementing upper and / or lower CT thresholds to accurately compare performances between individuals.

  20. Strength of biodegradable polypropylene tapes filled with a modified starch

    Science.gov (United States)

    Vinidiktova, N. S.; Ermolovich, O. A.; Goldade, V. A.; Pinchuk, L. S.

    2006-05-01

    The possibility of creating composite materials with high deformation and strength characteristics based on polypropylene (PP) and a natural polysaccharide in the form of a modified starch (MS) has been studied. The modified starch is shown to interact chemically with functional groups of PP, thereby positively affecting the physicomechanical properties, structure, and water absorption properties of films and oriented flat fibers based on starch-filled PP. The strength characteristics of both oriented and unoriented composites are 1.5-2.0 times as high as those of the initial PP. The water absorption ability of the materials varies symbatically with content of MS, which points to the dominant contribution of interactions at the PP-MS interface. The introduction of MS into synthetic polymers offers a possibility of producing new ecologically safe materials with high strength characteristics.

  1. Lifting strength in two-person teamwork.

    Science.gov (United States)

    Lee, Tzu-Hsien

    2016-01-01

    This study examined the effects of lifting range, hand-to-toe distance, and lifting direction on single-person lifting strengths and two-person teamwork lifting strengths. Six healthy males and seven healthy females participated in this study. Two-person teamwork lifting strengths were examined in both strength-matched and strength-unmatched groups. Our results showed that lifting strength significantly decreased with increasing lifting range or hand-to-toe distance. However, lifting strengths were not affected by lifting direction. Teamwork lifting strength did not conform to the law of additivity for both strength-matched and strength-unmatched groups. In general, teamwork lifting strength was dictated by the weaker of the two members, implying that weaker members might be exposed to a higher potential danger in teamwork exertions. To avoid such overexertion in teamwork, members with significantly different strength ability should not be assigned to the same team.

  2. Fine-structure energy levels, oscillator strengths and lifetimes

    Indian Academy of Sciences (India)

    We have done relativistic calculations for the evaluation of energy levels, oscillator strengths, transition probabilities and lifetimes for Cr VIII ion. Use has been made of configuration interaction technique by including Briet–Pauli approximation. The energies of various levels from the ground state to excited levels of 3s3p6, ...

  3. Crack formation and fracture energy of normal and high strength ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. The crack path through composite materials such as concrete depends on the mechanical interaction of inclusions with the cement-based matrix. Fracture energy depends on the deviations of a real crack from an idealized crack plane. Fracture energy and strain softening of normal, high strength, and self- ...

  4. Gamow-Teller Strength Distributions for Some Magic Nuclei

    Directory of Open Access Journals (Sweden)

    Necla ÇAKMAK

    2014-12-01

    Full Text Available The total Gamow-Teller strengths and their energy distributions for 96Zr, 96Sr, 54Ca, 28O, 24C and 14C have been obtained within the framework of Random Phase Approximation (RPA. The effective interaction potential has been described by considering the commutativity of the Gamow-Teller operator with the central part of the nuclear Hamiltonian.

  5. Cosmological Final Focus Systems

    International Nuclear Information System (INIS)

    Irwin, J

    2004-01-01

    We develop the many striking parallels between the dynamics of light streams from distant galaxies and particle beams in accelerator final focus systems. Notably the deflections of light by mass clumps are identical to the kicks arising from the long-range beam-beam interactions of two counter-rotating particle beams (known as parasitic crossings). These deflections have sextupolar as well as quadrupolar components. We estimate the strength of such distortions for a variety of circumstances and argue that the sextupolar distortions from clumping within clusters may be observable. This possibility is enhanced by the facts that (1) the sextupolar distortions of background galaxies is a factor of 5 smaller than the quadrupolar distortion, (2) the angular orientation of the sextupolar and quadrupolar distortions from a mass distribution would be correlated, appearing as a slightly curved image, (3) these effects should be spatially clumped on the sky

  6. Strength and life under creeping

    International Nuclear Information System (INIS)

    Pospishil, B.

    1982-01-01

    Certain examples of the application of the Lepin modified creep model, which are of interest from technical viewpoint, are presented. Mathematical solution of the dependence of strength limit at elevated temperatures on creep characteristics is obtained. Tensile test at elevated temperatures is a particular case of creep or relaxation and both strength limit and conventional yield strength at elevated temperatures are completely determined by parameters of state equations during creep. The equation of fracture summing during creep is confirmed not only by the experiment data when stresses change sporadically, but also by good reflection of durability curve using the system of equations. The system presented on the basis of parameters of the equations obtained on any part of durability curve, permits to forecast the following parameters of creep: strain, strain rate, life time, strain in the process of fracture. Tensile test at elevated temperature is advisable as an addition when determining creep curves (time-strain curves) [ru

  7. Withdrawal Strength and Bending Yield Strength of Stainless Steel Nails

    Science.gov (United States)

    Douglas R. Rammer; Samuel L. Zelinka

    2015-01-01

    It has been well established that stainless steel nails have superior corrosion performance compared to carbon steel or galvanized nails in treated wood; however, their mechanical fastening behavior is unknown. In this paper, the performance of stainless steel nails is examined with respect to two important properties used in wood connection design: withdrawal strength...

  8. Strength Properties of Aalborg Clay

    DEFF Research Database (Denmark)

    Iversen, Kirsten Malte; Nielsen, Benjaminn Nordahl; Augustesen, Anders Hust

    glacial time are characterised by the absence of this mussel. These deposits are named Aalborg Clay and Aalborg Sand. In the city of Aalborg, a fill layer superposes Aalborg Clay. This layer is at some places found to be 6m thick. This fill layer does not provide sufficient bearing capacity, which has...... resulted in many damaged buildings in Aalborg. To provide sufficient bearing capacity it is therefore necessary either to remove the fill or to construct the building on piles. Both methods imply that the strength of Aalborg Clay is important for the construction. This paper evaluates the strength...

  9. Topological strength of magnetic skyrmions

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D.; Ramos, J.G.G.S.; Rodrigues, E.I.B.

    2017-02-01

    This work deals with magnetic structures that attain integer and half-integer skyrmion numbers. We model and solve the problem analytically, and show how the solutions appear in materials that engender distinct, very specific physical properties, and use them to describe their topological features. In particular, we found a way to model skyrmion with a large transition region correlated with the presence of a two-peak skyrmion number density. Moreover, we run into the issue concerning the topological strength of a vortex-like structure and suggest an experimental realization, important to decide how to modify and measure the topological strength of the magnetic structure.

  10. Random matrix theory for transition strengths: Applications and open questions

    Science.gov (United States)

    Kota, V. K. B.

    2017-12-01

    Embedded random matrix ensembles are generic models for describing statistical properties of finite isolated interacting quantum many-particle systems. A finite quantum system, induced by a transition operator, makes transitions from its states to the states of the same system or to those of another system. Examples are electromagnetic transitions (then the initial and final systems are same), nuclear beta and double beta decay (then the initial and final systems are different) and so on. Using embedded ensembles (EE), there are efforts to derive a good statistical theory for transition strengths. With m fermions (or bosons) in N mean-field single particle levels and interacting via two-body forces, we have with GOE embedding, the so called EGOE(1+2). Now, the transition strength density (transition strength multiplied by the density of states at the initial and final energies) is a convolution of the density generated by the mean-field one-body part with a bivariate spreading function due to the two-body interaction. Using the embedding U(N) algebra, it is established, for a variety of transition operators, that the spreading function, for sufficiently strong interactions, is close to a bivariate Gaussian. Also, as the interaction strength increases, the spreading function exhibits a transition from bivariate Breit-Wigner to bivariate Gaussian form. In appropriate limits, this EE theory reduces to the polynomial theory of Draayer, French and Wong on one hand and to the theory due to Flambaum and Izrailev for one-body transition operators on the other. Using spin-cutoff factors for projecting angular momentum, the theory is applied to nuclear matrix elements for neutrinoless double beta decay (NDBD). In this paper we will describe: (i) various developments in the EE theory for transition strengths; (ii) results for nuclear matrix elements for 130Te and 136Xe NDBD; (iii) important open questions in the current form of the EE theory.

  11. Strengths, Weaknesses, Opportunities and Threats

    NARCIS (Netherlands)

    Bull, J.W.; Jobstvogt, N.; Böhnke-Henrichs, A.; Mascarenhas, A.; Sitas, N.; Baulcomb, C.; Lambini, C.K.; Rawlins, M.; Baral, H.; Zähringer, J.; Carter-Silk, E.; Balzan, M.V.; Kenter, J.O.; Häyhä, T.; Petz, K.; Koss, R.

    2016-01-01

    The ecosystem services concept (ES) is becoming a cornerstone of contemporary sustainability thought. Challenges with this concept and its applications are well documented, but have not yet been systematically assessed alongside strengths and external factors that influence uptake. Such an

  12. Polynomial expansions and transition strengths

    International Nuclear Information System (INIS)

    Draayer, J.P.

    1980-01-01

    The subject is statistical spectroscopy applied to determining strengths and strength sums of excitation processes in nuclei. The focus will be on a ds-shell isoscalar E2 study with detailed shell-model results providing the standard for comparison; similar results are available for isovector E2 and M1 and E4 transitions as well as for single-particle transfer and ν +- decay. The present study is intended to serve as a tutorial for applications where shell-model calculations are not feasible. The problem is posed and a schematic theory for strengths and sums is presented. The theory is extended to include the effect of correlations between H, the system Hamiltonian, and theta, the excitation operator. Associated with correlation measures is a geometry that can be used to anticipate the goodness of a symmetry. This is illustrated for pseudo SU(3) in the fp-shell. Some conclusions about fluctuations and collectivity that one can deduce from the statistical results for strengths are presented

  13. On strength of porous material

    DEFF Research Database (Denmark)

    Nielsen, Lauge Fuglsang

    1999-01-01

    The question of non-destructive testing of porous materials has always been of interest for the engineering profession. A number of empirically based MOE-MOR relations between stiffness (Modulus Of Elasticity) and strength (Modulus OF Rupture) of materials have been established in order to control...

  14. Strengths, weaknesses, opportunities and threats

    DEFF Research Database (Denmark)

    Bull, Joseph William; Jobstvogt, N.; Böhnke-Henrichs, A.

    2016-01-01

    The ecosystem services concept (ES) is becoming a cornerstone of contemporary sustainability thought. Challenges with this concept and its applications are well documented, but have not yet been systematically assessed alongside strengths and external factors that influence uptake. Such an assess...

  15. Comparing strengths of beliefs explicitly

    NARCIS (Netherlands)

    Ghosh, S.; de Jongh, D.

    2013-01-01

    Inspired by a similar use in provability logic, formulas p > B q and p ≥ B q are introduced in the existing logical framework for discussing beliefs to express that the strength of belief in p is greater than (or equal to) that in q. Besides its usefulness in studying the properties of the concept

  16. Strength training for the warfighter.

    Science.gov (United States)

    Kraemer, William J; Szivak, Tunde K

    2012-07-01

    Optimizing strength training for the warfighter is challenged by past training philosophies that no longer serve the modern warfighter facing the "anaerobic battlefield." Training approaches for integration of strength with other needed physical capabilities have been shown to require a periodization model that has the flexibility for changes and is able to adapt to ever-changing circumstances affecting the quality of workouts. Additionally, sequencing of workouts to limit over-reaching and development of overtraining syndromes that end in loss of duty time and injury are paramount to long-term success. Allowing adequate time for rest and recovery and recognizing the negative influences of extreme exercise programs and excessive endurance training will be vital in moving physical training programs into a more modern perspective as used by elite strength-power anaerobic athletes in sports today. Because the warfighter is an elite athlete, it is time that training approaches that are scientifically based are updated within the military to match the functional demands of modern warfare and are given greater credence and value at the command levels. A needs analysis, development of periodized training modules, and individualization of programs are needed to optimize the strength of the modern warfighter. We now have the knowledge, professional coaches and nonprofit organization certifications with continuing education units, and modern training technology to allow this to happen. Ultimately, it only takes command decisions and implementation to make this possible.

  17. Modeling of Sylgard Adhesive Strength

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, Ralph Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-03

    Sylgard is the name of a silicone elastomeric potting material manufactured by Dow Corning Corporation.1 Although the manufacturer cites its low adhesive strength as a feature of this product, thin layers of Sylgard do in fact have a non-negligible strength, which has been measured in recent tensile and shear debonding tests. The adhesive strength of thin layers of Sylgard potting material can be important in applications in which components having signi cantly di erent thermal expansion properties are potted together, and the potted assembly is subjected to temperature changes. The tensile and shear tractions developed on the potted surfaces of the components can cause signi cant internal stresses, particularly for components made of low-strength materials with a high area-to-volume ratio. This report is organized as follows: recent Sylgard debonding tests are rst brie y summarized, with particular attention to the adhesion between Sylgard and PBX 9501, and also between Sylgard and aluminum. Next, the type of numerical model that will be used to simulate the debonding behavior exhibited in these tests is described. Then the calibration of the debonding model will be illustrated. Finally, the method by which the model parameters are adjusted (scaled) to be applicable to other, non- tested bond thicknesses is summarized, and all parameters of the model (scaled and unscaled) are presented so that other investigators can reproduce all of the simulations described in this report as well as simulations of the application of interest.

  18. The strength of friendship ties in proximity sensor data.

    Directory of Open Access Journals (Sweden)

    Vedran Sekara

    Full Text Available Understanding how people interact and socialize is important in many contexts from disease control to urban planning. Datasets that capture this specific aspect of human life have increased in size and availability over the last few years. We have yet to understand, however, to what extent such electronic datasets may serve as a valid proxy for real life social interactions. For an observational dataset, gathered using mobile phones, we analyze the problem of identifying transient and non-important links, as well as how to highlight important social interactions. Applying the Bluetooth signal strength parameter to distinguish between observations, we demonstrate that weak links, compared to strong links, have a lower probability of being observed at later times, while such links-on average-also have lower link-weights and probability of sharing an online friendship. Further, the role of link-strength is investigated in relation to social network properties.

  19. The strength of friendship ties in proximity sensor data.

    Science.gov (United States)

    Sekara, Vedran; Lehmann, Sune

    2014-01-01

    Understanding how people interact and socialize is important in many contexts from disease control to urban planning. Datasets that capture this specific aspect of human life have increased in size and availability over the last few years. We have yet to understand, however, to what extent such electronic datasets may serve as a valid proxy for real life social interactions. For an observational dataset, gathered using mobile phones, we analyze the problem of identifying transient and non-important links, as well as how to highlight important social interactions. Applying the Bluetooth signal strength parameter to distinguish between observations, we demonstrate that weak links, compared to strong links, have a lower probability of being observed at later times, while such links-on average-also have lower link-weights and probability of sharing an online friendship. Further, the role of link-strength is investigated in relation to social network properties.

  20. EUROPEAN URBANIZATION – BETWEEN STRENGTHS AND RISKS

    Directory of Open Access Journals (Sweden)

    Marcela Danu

    2013-12-01

    Full Text Available On the European continent, urban population, representing a significant segment of the market, with features specific to a particular model of purchase, consumption, lifestyle, etc. , has the potential for growth. The possible effects of this increase (strengths or risks, include: increasing opportunities for employment, increasing level and structure of demand for consumer goods and, in conjunction, of the level and structure of supply, raising of the standard of living, changing requirements and personal taste level population, increased interaction, socializing, psycho-social conversions on the recently urbanised population as well as for the people there, etc. but also the increase in demand for land areas intended for dwellings, commercial premises and hence reducing spaces with vegetation, increasing the degree of concentration of the population in a small grounds, effects on air quality, etc. This study highlights dynamic and interdependent effects of European urbanization on the human population, businesses, and the environment.

  1. Strength of Coriolis Coupling in actinide nuclei

    International Nuclear Information System (INIS)

    Peker, L.K.; Rasmussen, J.O.; Hamilton, J.H.

    1982-01-01

    Coriolis Coupling V/sub cor/ plays an important role in deformed nuclei. V/sub cor/ is proportional to h 2 /J[j (j + 1) -Ω (Ω + 1)]/sup 1/2/ and therefore is particularly significant in the nuclei with large j and low Ω Nilsson levels close to Fermi surface: n(i/sub 13/2/) in A = 150 to 170 rare-earth nuclei and p(i/sub 13/2/) and n(j/sub 15/2/) in A greater than or equal to 224 actinide nuclei. Because of larger j (n(j/sub 15/2/) versus n(i/sub 13/2/)) and smaller deformations (β approx. = 0.22 versus β 0.28) it was reasonable to expect that in actinide nuclei Coriolis effects are stronger than in the rare earth nuclei. Recently it was realized that the strength of observed Coriolis effects depends not only on the genuine Coriolis Coupling but also on the interplay between Coriolis ad pairing forces which leads to an interference between the wave functions of two mixing rotational bands. As a consequence the effective interaction V/sub eff/ of both bands is an oscillating function of the degree of shell filling (or chemical potential lambda F). It was shown that in the rare earth nuclei this interference strongly influenced conclusions about the trends in the Coriolis coupling strength and explained many of the observed band-mixing features (the sharpness of back banding curves, details of the blocking effect etc.). From theoretical analysis it was concluded that in the majority of actinide nuclei the effective interaction V/sub eff/ is strong, and therefore the Coriolis band-mixing have to be very strong. In this paper we would like to demonstrate that contrary to these predictions experimental data suggest that Coriolis band mixing in studied actinide nuclei is relatively weak and possibly significantly weaker than in rare earth nuclei

  2. Depletion interactions in lyotropic nematics

    NARCIS (Netherlands)

    Schoot, van der P.P.A.M.

    2000-01-01

    A theoretical study of depletion interactions between pairs of small, globular colloids dispersed in a lyotropic nematic of hard, rodlike particles is presented. We find that both the strength and range of the interaction crucially depends on the configuration of the spheres relative to the nematic

  3. Muscle Strength and Poststroke Hemiplegia

    DEFF Research Database (Denmark)

    Kristensen, Otto H; Stenager, Egon; Dalgas, Ulrik

    2017-01-01

    undergone peer review; and (4) were available in English or Danish. DATA EXTRACTION: The psychometric properties of isokinetic dynamometry were reviewed with respect to reliability, validity, and responsiveness. Furthermore, comparisons of strength between paretic, nonparetic, and comparable healthy muscles...... isokinetic dynamometry. DATA SOURCES: A systematic literature search of 7 databases was performed. STUDY SELECTION: Included studies (1) enrolled participants with definite poststroke hemiplegia according to defined criteria; (2) assessed muscle strength or power by criterion isokinetic dynamometry; (3) had...... were reviewed. DATA SYNTHESIS: Twenty studies covering 316 PPSH were included. High intraclass correlation coefficient (ICC) inter- and intrasession reliability was reported for isokinetic dynamometry, which was independent of the tested muscle group, contraction mode, and contraction velocity...

  4. Electric quadrupole strength in nuclei

    International Nuclear Information System (INIS)

    Kirson, M.W.

    1979-01-01

    Isoscalar electric quadrupole strength distributions in nuclei are surveyed, and it is concluded that the strength is shared, in most cases, roughly equally between low-lying transitions and the giant quadrupole state. The same is not true of the isovector case. A simple extension of the schematic model gives a remarkably successul description of the data, and emphasizes the vital importance of the coupling between high-lying and low-lying quadrupole modes. The standadrd simple representation of the giant quadrupole resonance as produced by operating on the nuclear ground state with the quadrupole transition operator is not applicable to the isoscalar case. It is suggested that giant resonances fall into broad classes of similar states, with considerable qualitative differences between the distinct classes. (author)

  5. Line strengths in WN stars

    International Nuclear Information System (INIS)

    Leep, E.M.

    1982-01-01

    The author has analyzed high-dispersion spectra of over 100 WN stars in the Galaxy and the Large Magellenic Cloud (LMC). Most of the spectra were obtained through 4-m telescopes (Conti, Leep, and Perry 1981). The measured strengths of the WN classification lines N III lambdalambda4634-41, N IV lambda4057, N V lambda4604 (Smith 1968) for stars on WN subtypes 2.5-8 are shown. The assignments of WN subtypes are based on visual estimates of ratios of line strengths according to the scheme of Smith (1968), except that stars appearing to be earlier than WN3 are classified as WN2 or WN2.5 as explained by van der Hucht et al. (1981) and by Conti, Leep and Perry (1981). (Auth.)

  6. Weak interaction rates

    International Nuclear Information System (INIS)

    Sugarbaker, E.

    1995-01-01

    I review available techniques for extraction of weak interaction rates in nuclei. The case for using hadron charge exchange reactions to estimate such rates is presented and contrasted with alternate methods. Limitations of the (p,n) reaction as a probe of Gamow-Teller strength are considered. Review of recent comparisons between beta-decay studies and (p,n) is made, leading to cautious optimism regarding the final usefulness of (p,n)- derived GT strengths to the field of astrophysics. copyright 1995 American Institute of Physics

  7. Immediate repair bond strengths of microhybrid, nanohybrid and nanofilled composites after different surface treatments

    NARCIS (Netherlands)

    Rinastiti, Margareta; Siswomihardjo, Widowati; Busscher, Henk J.; Ozcan, Mutlu

    Objectives: To evaluate immediate repair bond strengths and failure types of resin composites with and without surface conditioning and characterize the interacting composite surfaces by their surface composition and roughness. Methods: Microhybrid, nanohybrid and nanofilled resin composites were

  8. Soil strength and forest operations

    OpenAIRE

    Beekman, F.

    1987-01-01

    The use of heavy machinery and transport vehicles is an integral part of modern forest operations. This use often causes damage to the standing trees and to the soil. In this study the effects of vehicle traffic on the soil are analysed and the possible consequences for forest management discussed. The study is largely restricted to sandy and loamy soils because of their importance for Dutch forestry.

    Soil strength, defined as the resistance of soil structure against the impa...

  9. Electronic Correlation Strength of Pu

    DEFF Research Database (Denmark)

    Svane, A.; C. Albers, R.; E. Christensen, N.

    2013-01-01

    A new electronic quantity, the correlation strength, is defined as a necessary step for understanding the properties and trends in strongly correlated electronic materials. As a test case, this is applied to the different phases of elemental Pu. Within the GW approximation we have surprisingly...... found a "universal" scaling relationship, where the f-electron bandwidth reduction due to correlation effects is shown to depend only upon the local density approximation (LDA) bandwidth and is otherwise independent of crystal structure and lattice constant....

  10. Strength and Microstructure of Ceramics

    Science.gov (United States)

    1989-11-01

    Forex - one particular alumina ceramic, I our own detailed crack ample, the relatively large values of r, and c* for the VI observations, and those of...particularly toughness indices, 1i71", indicating that there is sonic the c° , T parameters. However, the indentation mcth- kind of trade -o1Tbetwecn...macroscopic and microsnpic odology takes us closer to the strengths of specimens toughness levels, and that this trade -off is cont’olled by with natural

  11. Long range supergravity coupling strengths

    International Nuclear Information System (INIS)

    Kenyon, I.R.

    1991-01-01

    A limit of 2x10 -13 has recently been deduced for the fractional difference between the gravitational masses of the K 0 and anti K 0 mesons. This limit is applied here to put stringent limits on the strengths of the long range vector-scalar gravitational couplings envisaged in supergravity theories. A weaker limit is inferred from the general relativistic fit to the precession of the orbit of the pulsar PSR1913+16. (orig.)

  12. The German Version of the Strengths Use Scale: The Relation of Using Individual Strengths and Well-being

    Directory of Open Access Journals (Sweden)

    Alexandra Huber

    2017-04-01

    Full Text Available Theoretical perspectives in positive psychology have considered the possession and use of strengths equally but in applied research more studies focused on having them, probably due to the absence of psychometrically adequate scales. Therefore, the aim of this study was to assess the psychometric characteristics of the German language version of the Strengths Use Scale (SUS and to explore relationships between strengths use and several indicator measures of well-being: the presence of positive and the absence of negative affect, self-esteem as identity aspect, vitality as self-regulatory resource, and stress for capturing the evaluation of difficulties and obstacles impinging on well-being. The original English version of the SUS was translated following recommended independent forward-backward translation techniques. Exploratory and confirmatory factor analyses were conducted, including a German-speaking convenience sample of university students (N = 374. Additionally, the relations of strengths use and well-being indicators were analyzed. Factorial validity revealed a single-factor structure of the German version of the SUS, explaining 58.4% variance (factor loadings: 0.58 to 0.86, approving the scale’s design and showing high internal consistency (Cronbach’s α 0.95. The hypothesized positive relationships of strengths use with positive affect, self-esteem, and vitality were confirmed as well as the negative relationships with negative affect and stress. The German version of the SUS is psychometrically sound and data indicate that individual strengths use and well-being related measures interact. The instrument can be recommended for future research questions such as if and how the promotion of applying individual strengths during education enhances levels of well-being, or how the implementation of strengths use in job-design guidelines or working conditions can result in higher levels of well-being or healthiness.

  13. Crushing Strength of Ship Structures

    DEFF Research Database (Denmark)

    Cerup-Simonsen, Bo; Abramowicz, W.; Høstgaard-Brene, C.N.S.

    1999-01-01

    The crushing response of ship structures is of primary importance to the designers and practicing engineers concerned with accidental loading and accident reconstruction of marine vehicles. Ship to-ship collisions, ship-harbor infrastructure interaction or ship-offshore structure interaction are ...

  14. The relationship between compressive strength and flexural strength of pavement geopolymer grouting material

    Science.gov (United States)

    Zhang, L.; Han, X. X.; Ge, J.; Wang, C. H.

    2018-01-01

    To determine the relationship between compressive strength and flexural strength of pavement geopolymer grouting material, 20 groups of geopolymer grouting materials were prepared, the compressive strength and flexural strength were determined by mechanical properties test. On the basis of excluding the abnormal values through boxplot, the results show that, the compressive strength test results were normal, but there were two mild outliers in 7days flexural strength test. The compressive strength and flexural strength were linearly fitted by SPSS, six regression models were obtained by linear fitting of compressive strength and flexural strength. The linear relationship between compressive strength and flexural strength can be better expressed by the cubic curve model, and the correlation coefficient was 0.842.

  15. Transference of kettlebell training to strength, power, and endurance.

    Science.gov (United States)

    Manocchia, Pasquale; Spierer, David K; Lufkin, Adrienne K S; Minichiello, Jacqueline; Castro, Jessica

    2013-02-01

    Kettlebells are a popular implement in many strength and conditioning programs, and their benefits are touted in popular literature, books, and videos. However, clinical data on their efficacy are limited. The purpose of this study was to examine whether kettlebell training transfers strength and power to weightlifting and powerlifting exercises and improves muscular endurance. Thirty-seven subjects were assigned to an experimental (EXP, n = 23; mean age = 40.9 ± 12.9 years) or a control group (CON; n = 14; mean age = 39.6 ± 15.8 years), range 18-72 years. The participants were required to perform assessments including a barbell clean and jerk, barbell bench press, maximal vertical jump, and 45° back extensions to volitional fatigue before and after a 10-week kettlebell training program. Training was structured in a group setting for 2 d·wk(-1) for 10 weeks. A repeated measures analysis of variance was conducted to determine group × time interactions and main effects. Post hoc pairwise comparisons were conducted when appropriate. Bench press revealed a time × group interaction and a main effect (p power and strength in response to 10 weeks of training with kettlebells. Traditional training methods may not be convenient or accessible for strength and conditioning specialists, athletes, coaches, and recreational exercisers. The current data suggest that kettlebells may be an effective alternative tool to improve performance in weightlifting and powerlifting.

  16. Isometric and swallowing tongue strength in healthy adults.

    Science.gov (United States)

    Todd, J Tee; Lintzenich, Catherine Rees; Butler, Susan G

    2013-10-01

    The tongue contributes to a safe swallow. It facilitates bolus control during mastication, maintains a bolus in the oral cavity to prevent premature entry of the bolus into the hypopharynx, and helps generate pressure in the hypopharynx during swallowing. This study examined isometric tongue strength and tongue pressure measured during swallowing in healthy young and older adults. Prospective group design. One hundred twenty-six healthy individuals who were recruited as part of a larger study on swallowing participated in this study. Participants were divided into three age groups: 20 to 40 years, 41 to 60 years, and ≥61 years. A KayPentax Digital Swallowing Workstation with an air-filled bulb array was placed on the tongue of each participant (anterior to posterior). Participants completed three isometric tongue presses and three swallows. Repeated measures analyses of variance revealed a significant main effect of age (P = .01) and gender by tongue bulb location interaction (P = .02) for isometric tongue strength. That is, older adults had lower isometric tongue strength than young adults, and females had a greater difference between anterior and posterior tongue strength than males. Tongue strength during swallowing yielded significantly greater anterior versus posterior tongue pressure. This study comprises one of the largest in terms of number of healthy participants reported to date and confirms previous findings that isometric tongue strength decreases with age. Furthermore, given young and older adults generate similar swallowing pressures, swallowing is a submaximal strength activity, yet older adults have less functional reserve. 4. Copyright © 2013 The American Laryngological, Rhinological, and Otological Society, Inc.

  17. Astrocytes regulate heterogeneity of presynaptic strengths in hippocampal networks

    Science.gov (United States)

    Letellier, Mathieu; Park, Yun Kyung; Chater, Thomas E.; Chipman, Peter H.; Gautam, Sunita Ghimire; Oshima-Takago, Tomoko; Goda, Yukiko

    2016-01-01

    Dendrites are neuronal structures specialized for receiving and processing information through their many synaptic inputs. How input strengths are modified across dendrites in ways that are crucial for synaptic integration and plasticity remains unclear. We examined in single hippocampal neurons the mechanism of heterosynaptic interactions and the heterogeneity of synaptic strengths of pyramidal cell inputs. Heterosynaptic presynaptic plasticity that counterbalances input strengths requires N-methyl-d-aspartate receptors (NMDARs) and astrocytes. Importantly, this mechanism is shared with the mechanism for maintaining highly heterogeneous basal presynaptic strengths, which requires astrocyte Ca2+ signaling involving NMDAR activation, astrocyte membrane depolarization, and L-type Ca2+ channels. Intracellular infusion of NMDARs or Ca2+-channel blockers into astrocytes, conditionally ablating the GluN1 NMDAR subunit, or optogenetically hyperpolarizing astrocytes with archaerhodopsin promotes homogenization of convergent presynaptic inputs. Our findings support the presence of an astrocyte-dependent cellular mechanism that enhances the heterogeneity of presynaptic strengths of convergent connections, which may help boost the computational power of dendrites. PMID:27118849

  18. A Matter of Degree: Strength of Brain Asymmetry and Behaviour

    Directory of Open Access Journals (Sweden)

    Lesley J. Rogers

    2017-04-01

    Full Text Available Research on a growing number of vertebrate species has shown that the left and right sides of the brain process information in different ways and that lateralized brain function is expressed in both specific and broad aspects of behaviour. This paper reviews the available evidence relating strength of lateralization to behavioural/cognitive performance. It begins by considering the relationship between limb preference and behaviour in humans and primates from the perspectives of direction and strength of lateralization. In birds, eye preference is used as a reflection of brain asymmetry and the strength of this asymmetry is associated with behaviour important for survival (e.g., visual discrimination of food from non-food and performance of two tasks in parallel. The same applies to studies on aquatic species, mainly fish but also tadpoles, in which strength of lateralization has been assessed as eye preferences or turning biases. Overall, the empirical evidence across vertebrate species points to the conclusion that stronger lateralization is advantageous in a wide range of contexts. Brief discussion of interhemispheric communication follows together with discussion of experiments that examined the effects of sectioning pathways connecting the left and right sides of the brain, or of preventing the development of these left-right connections. The conclusion reached is that degree of functional lateralization affects behaviour in quite similar ways across vertebrate species. Although the direction of lateralization is also important, in many situations strength of lateralization matters more. Finally, possible interactions between asymmetry in different sensory modalities is considered.

  19. D-state Rydberg electrons interacting with ultracold atoms

    Energy Technology Data Exchange (ETDEWEB)

    Krupp, Alexander Thorsten

    2014-10-02

    This thesis was established in the field of ultracold atoms where the interaction of highly excited D-state electrons with rubidium atoms was examined. This work is divided into two main parts: In the first part we study D-state Rydberg molecules resulting from the binding of a D-state Rydberg electron to a ground state rubidium atom. We show that we can address specific rovibrational molecular states by changing our laser detuning and thus create perfectly aligned axial or antialigned toroidal molecules, in good agreement with our theoretical calculations. Furthermore the influence of the electric field on the Rydberg molecules was investigated, creating novel states which show a different angular dependence and alignment. In the second part of this thesis we excite single D-state Rydberg electrons in a Bose-Einstein condensate. We study the lifetime of these Rydberg electrons, the change of the shape of our condensate and the atom losses in the condensate due to this process. Moreover, we observe quadrupolar shape oscillations of the whole condensate created by the consecutive excitation of Rydberg atoms and compare all results to previous S-state measurements. In the outlook we propose a wide range of further experiments including the proposal of imaging a single electron wavefunction by the imprint of its orbit into the Bose-Einstein condensate.

  20. The significance of water ionic strength on aluminium toxicity in brown trout (Salmo trutta L.)

    International Nuclear Information System (INIS)

    Alstad, Nina E.W.; Kjelsberg, Birgitte M.; Voellestad, L. Asbjoern; Lydersen, Espen; Poleo, Antonio B.S.

    2005-01-01

    The toxicity of aluminium to fish is related to interactions between aluminium and the gill surface. We investigated the possible effect of water ionic strength on this interaction. The mortality of brown trout (Salmo trutta L.) exposed to three different degrees of Al polymerisation was compared in water with increased ionic strength (mean 7.31 x 10 -4 M) after additions of the base cations Ca 2+ , Mg 2+ , Na + or K + , and in water with no such addition (mean ionic strength 5.58 x 10 -4 M). Only a very slight ameliorating effect of increased ionic strength was observed, while the degree of Al polymerisation was of major importance in fish mortality. In addition, it was observed that smaller fish survived the Al exposures for a longer time than larger fish. We hypothesise that this is because larger fish are more susceptible to hypoxia than smaller fish. - Ionic strength has a slight ameliorating effect on Al toxicity in brown trout

  1. Strength of mortar containing rubber tire particle

    Science.gov (United States)

    Jusoh, M. A.; Abdullah, S. R.; Adnan, S. H.

    2018-04-01

    The main focus in this investigation is to determine the strength consist compressive and tensile strength of mortar containing rubber tire particle. In fact, from the previous study, the strength of mortar containing waste rubber tire in mortar has a slightly decreases compare to normal mortar. In this study, rubber tire particle was replacing on volume of fine aggregate with 6%. 9% and 12%. The sample were indicated M0 (0%), M6 (6%), M9 (9%) and M12 (12%). In this study, two different size of sample used with cube 100mm x 100mm x 100mm for compressive strength and 40mm x 40mm x 160mm for flexural strength. Morphology test was conducted by using Scanning electron microscopic (SEM) were done after testing compressive strength test. The concrete sample were cured for day 3, 7 and 28 before testing. Results compressive strength and flexural strength of rubber mortar shown improved compare to normal mortar.

  2. optimizing compressive strength characteristics of hollow building

    African Journals Online (AJOL)

    eobe

    Keywords: hollow building Blocks, granite dust, sand, partial replacement, compressive strength. 1. INTRODUCTION ... exposed to extreme climate. The physical ... Sridharan et al [13] conducted shear strength studies on soil-quarry dust.

  3. Elastic buckling strength of corroded steel plates

    Indian Academy of Sciences (India)

    structural safety assessment of corroded structures, residual strength should be ... Rahbar-Ranji (2001) has proposed a spectrum for random simulation of ... The main aim of the present work is to investigate the buckling strength of simply ...

  4. CADDIS Volume 2. Sources, Stressors and Responses: Ionic Strength

    Science.gov (United States)

    Introduction to the ionic strength module, when to list ionic strength as a candidate cause, ways to measure ionic strength, simple and detailed conceptual diagrams for ionic strength, ionic strength module references and literature reviews.

  5. Determination of giant resonance strengths

    International Nuclear Information System (INIS)

    Serr, F.E.

    1983-01-01

    Using theoretical strength functions to describe the different giant resonances expected at excitation energies of the order of (60-85)/Asup(1/3) MeV, we calculate the double differential cross sections d 2 sigma/dΩ dE associated with the reactions 208 Pb(α, α') and 90 Zr(α, α') (Esub(α) = 152 MeV). The angular distributions for the giant quadrupole and giant monopole resonances obtained from fits to these spectra, making simple, commonly used assumptions for the peak shapes and background, are compared to the original angular distributions. The differences between them are an indication of some of the uncertainties affecting the giant resonance strengths extracted from hadron inelastic scattering data. Fits to limited angular regions lead to errors of up to 50% in the value of the energy-weighted sum rule, depending on the angles examined. While it seems possible to extract the correct EWSR for the GMR by carrying out the analyses at 0 0 , no single privileged angle seems to exist in the case of the GQR. (orig.)

  6. Strengths and Satisfaction across the Adult Lifespan

    Science.gov (United States)

    Isaacowitz, Derek M.; Vaillant, George E.; Seligman, Martin E. P.

    2003-01-01

    Positive psychology has recently developed a classification of human strengths (Peterson & Seligman, in press). We aimed to evaluate these strengths by investigating the strengths and life satisfaction in three adult samples recruited from the community (young adult, middle-aged, and older adult), as well as in the surviving men of the Grant study…

  7. Relationship between the edgewise compression strength of ...

    African Journals Online (AJOL)

    The results of this study were used to determine the linear regression constants in the Maltenfort model by correlating the measured board edgewise compression strength (ECT) with the predicted strength, using the paper components' compression strengths, measured with the short-span compression test (SCT) and the ...

  8. Strength of Ship Plates under Combined Loading

    DEFF Research Database (Denmark)

    Cui, W.; Wang, Y.; Pedersen, Preben Terndrup

    2002-01-01

    Strength of ship plates plays a significant role in the ultimate strength analysis of ship structures. In recent years several authors have proposed simplified analytical methods to calculate the ultimate strength of unstiffened plates. The majority of these investigations deal with plates subjec...

  9. Strength of ship plates under combined loading

    DEFF Research Database (Denmark)

    Cui, Weiching; Wang, Yongjun; Pedersen, Preben Terndrup

    2000-01-01

    Strength of ship plates plays a significant role for the ultimate strength analysis of ship structures. In recent years several authors have proposed simplified methods to calculate the ultimate strength of unstiffened plates. The majority of these investigations deal with plates subjected to lon...

  10. Cobalt: for strength and color

    Science.gov (United States)

    Boland, Maeve A.; Kropschot, S.J.

    2011-01-01

    Cobalt is a shiny, gray, brittle metal that is best known for creating an intense blue color in glass and paints. It is frequently used in the manufacture of rechargeable batteries and to create alloys that maintain their strength at high temperatures. It is also one of the essential trace elements (or "micronutrients") that humans and many other living creatures require for good health. Cobalt is an important component in many aerospace, defense, and medical applications and is a key element in many clean energy technologies. The name cobalt comes from the German word kobold, meaning goblin. It was given this name by medieval miners who believed that troublesome goblins replaced the valuable metals in their ore with a substance that emitted poisonous fumes when smelted. The Swedish chemist Georg Brandt isolated metallic cobalt-the first new metal to be discovered since ancient times-in about 1735 and identified some of its valuable properties.

  11. High-strength beryllium block

    International Nuclear Information System (INIS)

    Pinto, N.P.; Keith, G.H.

    1977-01-01

    Beryllium billets hot isopressed using fine powder of high purity have exceptionally attractive properties; average tensile ultimate, 0.2% offset yield strength and elongation are 590 MPa, 430 MPa and 4.0% respectively. Properties are attributed to the fine grain size (about 4.0 μm average diameter) and the relatively low levels of BeO present as fine, well-dispersed particles. Dynamic properties, e.g., fracture toughness, are similar to those of standard grade, high-purity beryllium. The modulus of beryllium is retained to very high stress levels, and the microyield stress or precision elastic limit is higher than for other grades, including instrument grades. Limited data for billets made from normal-purity fine powders show similar room temperature properties. (author)

  12. Swimbladder on Fish Target Strength

    Directory of Open Access Journals (Sweden)

    Sunardi

    2008-08-01

    Full Text Available This paper discusses of target strength (TS for the Selar boops (Oxeye scad and Megalaspis cordyla (Torpedo scad, the most commercially fish in Malaysia. TS can be determined from in situ measurements and acoustic calculation of fish model. TS value, depth, and position (x-y-z of targeted fish can be viewed from echogram using FQ-80 Analyzer by in situ measurement. X-ray imaged can be deployed to develop the acoustic fish model. The percentage of length and upper surface area for swimbladder to body fish of Selar boops more than Megalaspis cordyla can be measured after X-ray process. The percentage of width and volume of swimbladders to its each body are no significantly difference for both fish. These data of swimbladder physic support the result of in situ measurement which TS of Megalaspis cordyla stronger Selar boops.

  13. Vortex dynamics during blade-vortex interactions

    Science.gov (United States)

    Peng, Di; Gregory, James W.

    2015-05-01

    Vortex dynamics during parallel blade-vortex interactions (BVIs) were investigated in a subsonic wind tunnel using particle image velocimetry (PIV). Vortices were generated by applying a rapid pitch-up motion to an airfoil through a pneumatic system, and the subsequent interactions with a downstream, unloaded target airfoil were studied. The blade-vortex interactions may be classified into three categories in terms of vortex behavior: close interaction, very close interaction, and collision. For each type of interaction, the vortex trajectory and strength variation were obtained from phase-averaged PIV data. The PIV results revealed the mechanisms of vortex decay and the effects of several key parameters on vortex dynamics, including separation distance (h/c), Reynolds number, and vortex sense. Generally, BVI has two main stages: interaction between vortex and leading edge (vortex-LE interaction) and interaction between vortex and boundary layer (vortex-BL interaction). Vortex-LE interaction, with its small separation distance, is dominated by inviscid decay of vortex strength due to pressure gradients near the leading edge. Therefore, the decay rate is determined by separation distance and vortex strength, but it is relatively insensitive to Reynolds number. Vortex-LE interaction will become a viscous-type interaction if there is enough separation distance. Vortex-BL interaction is inherently dominated by viscous effects, so the decay rate is dependent on Reynolds number. Vortex sense also has great impact on vortex-BL interaction because it changes the velocity field and shear stress near the surface.

  14. Preparation, mechanical strengths, and thermal

    Science.gov (United States)

    Inoue, A.; Furukawa, S.; Hagiwara, M.; Masumoto, T.

    1987-05-01

    Ni-based amorphous wires with good bending ductility have been prepared for Ni75Si8B17 and Ni78P12B10 alloys containing 1 to 2 at. pct Al or Zr by melt spinning in rotating water. The enhancement of the wire-formation tendency by the addition of Al has been clarified to be due to the increase in the stability of the melt jet through the formation of a thin A12O3 film on the outer surface. The maximum wire diameter is about 190 to 200 μm for the Ni-Si (or P)-B-Al alloys and increases to about 250 μm for the Ni-Si-B-Al-Cr alloys containing 4 to 6 at. pct Cr. The tensile fracture strength and fracture elongation are 2730 MPa and 2.9 pct for (Ni0.75Si0.08B0.17 99Al1) wire and 2170 MPa and 2.4 pct for (Ni0.78P0.12B0.1)99Al1 wire. These wires exhibit a fatigue limit under dynamic bending strain in air with a relative humidity of 65 pct; this limit is 0.50 pct for a Ni-Si-B-Al wire, which is higher by 0.15 pct than that of a Fe75Si10B15 amorphous wire. Furthermore, the Ni-base wires do not fracture during a 180-deg bending even for a sample annealed at temperatures just below the crystallization temperature, in sharp contrast to high embrittlement tendency for Fe-base amorphous alloys. Thus, the Ni-based amorphous wires have been shown to be an attractive material similar to Fe- and Co-based amorphous wires because of its high static and dynamic strength, high ductility, high stability to thermal embrittlement, and good corrosion resistance.

  15. Association Between Maximal Bench Press Strength and Isometric Handgrip Strength Among Breast Cancer Survivors.

    Science.gov (United States)

    Rogers, Benjamin H; Brown, Justin C; Gater, David R; Schmitz, Kathryn H

    2017-02-01

    To characterize the relationship between 1-repetition maximum (1-RM) bench press strength and isometric handgrip strength among breast cancer survivors. Cross-sectional study. Laboratory. Community-dwelling breast cancer survivors (N=295). Not applicable. 1-RM bench press strength was measured with a barbell and exercise bench. Isometric handgrip strength was measured using an isometric dynamometer, with 3 maximal contractions of the left and right hands. All measures were conducted by staff with training in clinical exercise testing. Among 295 breast cancer survivors, 1-RM bench press strength was 18.2±6.1kg (range, 2.2-43.0kg), and isometric handgrip strength was 23.5±5.8kg (range, 9.0-43.0kg). The strongest correlate of 1-RM bench press strength was the average isometric handgrip strength of both hands (r=.399; Pisometric handgrip strength of both hands overestimated 1-RM bench press strength by 4.7kg (95% limits of agreement, -8.2 to 17.6kg). In a multivariable linear regression model, the average isometric handgrip strength of both hands (β=.31; Pstrength (R 2 =.23). Isometric handgrip strength is a poor surrogate for 1-RM bench press strength among breast cancer survivors. 1-RM bench press strength and isometric handgrip strength quantify distinct components of muscular strength. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  16. Reference Values of Grip Strength, Prevalence of Low Grip Strength, and Factors Affecting Grip Strength Values in Chinese Adults.

    Science.gov (United States)

    Yu, Ruby; Ong, Sherlin; Cheung, Osbert; Leung, Jason; Woo, Jean

    2017-06-01

    The objectives of this study were to update the reference values of grip strength, to estimate the prevalence of low grip strength, and to examine the impact of different aspects of measurement protocol on grip strength values in Chinese adults. A cross-sectional survey of Chinese men (n = 714) and women (n = 4014) aged 18-102 years was undertaken in different community settings in Hong Kong. Grip strength was measured with a digital dynamometer (TKK 5401 Grip-D; Takei, Niigata, Japan). Low grip strength was defined as grip strength 2 standard deviations or more below the mean for young adults. The effects of measurement protocol on grip strength values were examined in a subsample of 45 men and women with repeated measures of grip strength taken with a hydraulic dynamometer (Baseline; Fabrication Enterprises Inc, Irvington, NY), using pair t-tests, intraclass correlation coefficient, and Bland and Altman plots. Grip strength was greater among men than among women (P values than the Baseline hydraulic dynamometer (P values were also observed when the measurement was performed with the elbow extended in a standing position, compared with that with the elbow flexed at 90° in a sitting position, using the same dynamometer (P values of grip strength and estimated the prevalence of low grip strength among Chinese adults spanning a wide age range. These findings might be useful for risk estimation and evaluation of interventions. However, grip strength measurements should be interpreted with caution, as grip strength values can be affected by type of dynamometer used, assessment posture, and elbow position. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  17. The Importance of Muscular Strength: Training Considerations.

    Science.gov (United States)

    Suchomel, Timothy J; Nimphius, Sophia; Bellon, Christopher R; Stone, Michael H

    2018-04-01

    This review covers underlying physiological characteristics and training considerations that may affect muscular strength including improving maximal force expression and time-limited force expression. Strength is underpinned by a combination of morphological and neural factors including muscle cross-sectional area and architecture, musculotendinous stiffness, motor unit recruitment, rate coding, motor unit synchronization, and neuromuscular inhibition. Although single- and multi-targeted block periodization models may produce the greatest strength-power benefits, concepts within each model must be considered within the limitations of the sport, athletes, and schedules. Bilateral training, eccentric training and accentuated eccentric loading, and variable resistance training may produce the greatest comprehensive strength adaptations. Bodyweight exercise, isolation exercises, plyometric exercise, unilateral exercise, and kettlebell training may be limited in their potential to improve maximal strength but are still relevant to strength development by challenging time-limited force expression and differentially challenging motor demands. Training to failure may not be necessary to improve maximum muscular strength and is likely not necessary for maximum gains in strength. Indeed, programming that combines heavy and light loads may improve strength and underpin other strength-power characteristics. Multiple sets appear to produce superior training benefits compared to single sets; however, an athlete's training status and the dose-response relationship must be considered. While 2- to 5-min interset rest intervals may produce the greatest strength-power benefits, rest interval length may vary based an athlete's training age, fiber type, and genetics. Weaker athletes should focus on developing strength before emphasizing power-type training. Stronger athletes may begin to emphasize power-type training while maintaining/improving their strength. Future research should

  18. Electromagnetic current in weak interactions

    International Nuclear Information System (INIS)

    Ma, E.

    1983-01-01

    In gauge models which unify weak and electromagnetic interactions, the weak neutral-current interaction also involves the electromagnetic current. The exact nature of such a component can be explored using e + e - experimental data. In recent years, the existence of a new component of the weak interaction has become firmly established, i.e., the neutral-current interaction. As such, it competes with the electromagnetic interaction whenever the particles involved are also charged, but at a very much lower rate because its effective strength is so small. Hence neutrino processes are best for the detection of the neutral-current interaction. However, in any gauge model which unifies weak and electromagnetic interactions, the weak neutral-current interaction also involves the electromagnetic current

  19. Traditional versus functional strength training: Effects on muscle strength and power in the elderly

    OpenAIRE

    Seiler, Hilde Lohne; Torstveit, Monica Klungland; Anderssen, Sigmund A.

    2013-01-01

    Published versiom of an article in the journal:Journal of Aging and Physical Activity. Also available from Human Kinetics: http://http://journals.humankinetics.com/japa-back-issues/japa-volume-21-issue-1-january/traditional-versus-functional-strength-training-effects-on-muscle-strength-and-power-in-the-elderly The aim was to determine whether strength training with machines vs. functional strength training at 80% of one-repetition maximum improves muscle strength and power among the elderl...

  20. OPTIMUM DESIGN OF ULTRAHIGH STRENGTH NANOLAYERED COMPOSITES

    Energy Technology Data Exchange (ETDEWEB)

    H. KUNG; ET AL

    2000-10-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Refinement of the microstructure in metallic multilayers from the micrometer-scale to the nanometer-scale often results in a break down of the classical Hall-Petch model relating strength to the microstructural length scale. The critical length scale at which this behavior breaks down is investigated both experimentally and theoretically. Using transmission electron microscopy and nanoindentation, we evaluated the microstructure and mechanical properties of Cu/Cr, Cu./Ni, and Cu/Nb multilayers that had different shear moduli mismatch between layers and lattice misfit strain between layers. Two-dimensional maps showing layer thickness and grain size ranges over which different deformation mechanisms operate were constructed using dislocation theory. The deformation mechanisms responsible for the breakdown of Hall-Petch behavior are discussed. By correlating the deformation mechanism maps with the experimental data, we show that these maps serve as guidelines for interpreting the scale-dependent deformation mechanisms in multilayers. Atomistic simulation was also used to evaluate the interaction between interfaces and glide dislocations to provide atomic scale insights into the deformation mechanisms.

  1. Microsphere Wetting, Meniscus Structure, and Capillary Interactions on a Curved Liquid Interface

    Science.gov (United States)

    Kim, Paul; Dinsmore, Anthony; Hoagland, David; Russell, Thomas

    A small spherical microparticle on a cylindrically curved liquid interface locally induces a quadrupolar interface deformation to maintain a constant contact angle about its wetted periphery. Measured by optical profilometry, this deformation was compared to a recent theoretical expression, and good agreement was noted for contact line shape, particle vertical position, and deformation vs. (distance, angle, particle size, interfacial curvature). Interface quadrupoles lead to particle capillary interactions in analogy to 2D electrostatic quadrupoles, and as one consequence, spheres on a cylindrical interface assemble tetragonally, i.e., into a square lattice. This assembly was monitored in the optical microscope, with particles interacting as predicted, into a square lattice aligned with the underlying cylindrical axis. These particles and assemblies were driven to the middle of the curved interface by capillary interaction with pinned liquid contact lines on each side of the liquid cylindrical section used in the experiments. These phenomena can inform the directed interfacial assembly of micro-sized spherical objects, with potential application in fabrication of functional devices and materials, encapsulation, and emulsification.

  2. Isometric shoulder strength in young swimmers.

    Science.gov (United States)

    McLaine, Sally J; Ginn, Karen A; Fell, James W; Bird, Marie-Louise

    2018-01-01

    The prevalence of shoulder pain in young swimmers is high. Shoulder rotation strength and the ratio of internal to external rotation strength have been reported as potential modifiable risk factors associated with shoulder pain. However, relative strength measures in elevated positions, which include flexion and extension, have not been established for the young swimmer. The aim of this study was to establish clinically useful, normative shoulder strength measures and ratios for swimmers (14-20 years) without shoulder pain. Cross-sectional, observational study. Swimmers (N=85) without a recent history of shoulder pain underwent strength testing of shoulder flexion and extension (in 140° abduction); and internal and external rotation (in 90° abduction). Strength tests were performed in supine using a hand-held dynamometer and values normalised to body weight. Descriptive statistics were calculated for strength and strength ratios (flexion:extension and internal:external rotation). Differences between groups (based on gender, history of pain, test and arm dominance) were explored using independent and paired t tests. Normative shoulder strength values and ratios were established for young swimmers. There was a significant difference (pdifferences in strength ratios. Relative strength of the dominant and non-dominant shoulders (except for extension); and for swimmers with and without a history of shoulder pain was not significantly different. A normal shoulder strength profile for the young swimmer has been established which provides a valuable reference for the clinician assessing shoulder strength in this population. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  3. Effects of core instability strength training on trunk muscle strength, spinal mobility, dynamic balance and functional mobility in older adults.

    Science.gov (United States)

    Granacher, Urs; Lacroix, Andre; Muehlbauer, Thomas; Roettger, Katrin; Gollhofer, Albert

    2013-01-01

    Age-related postural misalignment, balance deficits and strength/power losses are associated with impaired functional mobility and an increased risk of falling in seniors. Core instability strength training (CIT) involves exercises that are challenging for both trunk muscles and postural control and may thus have the potential to induce benefits in trunk muscle strength, spinal mobility and balance performance. The objective was to investigate the effects of CIT on measures of trunk muscle strength, spinal mobility, dynamic balance and functional mobility in seniors. Thirty-two older adults were randomly assigned to an intervention group (INT; n = 16, aged 70.8 ± 4.1 years) that conducted a 9-week progressive CIT or to a control group (n = 16, aged 70.2 ± 4.5 years). Maximal isometric strength of the trunk flexors/extensors/lateral flexors (right, left)/rotators (right, left) as well as of spinal mobility in the sagittal and the coronal plane was measured before and after the intervention program. Dynamic balance (i.e. walking 10 m on an optoelectric walkway, the Functional Reach test) and functional mobility (Timed Up and Go test) were additionally tested. Program compliance was excellent with participants of the INT group completing 92% of the training sessions. Significant group × test interactions were found for the maximal isometric strength of the trunk flexors (34%, p training-related improvements were found for spinal mobility in the sagittal (11%, p velocity (9%, p velocity (31%, p training regimen could be used as an adjunct or even alternative to traditional balance and/or resistance training. Copyright © 2012 S. Karger AG, Basel.

  4. Fragmentation of single-particle strength and the validity of the shell model

    International Nuclear Information System (INIS)

    Brand, M.G.E.; Rijsdijk, G.A.; Muller, F.A.; Allaart, K.; Dickhoff, W.H.

    1991-01-01

    The problem of missing spectroscopic strength in proton knock-out reactions is addressed by calculating this strength with a realistic interaction up to about a hundred MeV missing energy. An interaction suitably modified for short-range correlations (G-matrix) is employed in the calculation of the self-energy including all orbitals up to and including three major shells above the Fermi level for protons. The spectroscopic strength is obtained by solving the Dyson equation for the Green function with a self-energy up to second order in the interaction. Results for 48 Ca and 90 Zr are compared with recent (e,e'p) data. The calculated strength overestimates the data by about 10-15% of the independent particle shell-model (IPSM) sum rule. This is in accordance with what is expected from depletions calculated in infinite nuclear matter. Inclusion of higher order terms into the self-energy, especially the correlated motion of particles and holes, is found to be necessary to reproduce the observed fragmentation of strength in the low-energy region. The widths of the strength distributions compare well with empirical formulas which have been deduced from optical potentials. The validity of the conventional shell-model picture is connected with the relevance of Landau's quasiparticle picture for strongly interacting Fermi systems. (orig.)

  5. Possible stimuli for strength and power adaptation : acute metabolic responses.

    Science.gov (United States)

    Crewther, Blair; Cronin, John; Keogh, Justin

    2006-01-01

    The metabolic response to resistance exercise, in particular lactic acid or lactate, has a marked influence upon the muscular environment, which may enhance the training stimulus (e.g. motor unit activation, hormones or muscle damage) and thereby contribute to strength and power adaptation. Hypertrophy schemes have resulted in greater lactate responses (%) than neuronal and dynamic power schemes, suggesting possible metabolic-mediated changes in muscle growth. Factors such as age, sex, training experience and nutrition may also influence the lactate responses to resistance exercise and thereafter, muscular adaptation. Although the importance of the mechanical and hormonal stimulus to strength and power adaptation is well recognised, the contribution of the metabolic stimulus is largely unknown. Relatively few studies for example, have examined metabolic change across neuronal and dynamic power schemes, and not withstanding the fact that those mechanisms underpinning muscular adaptation, in relation to the metabolic stimulus, remain highly speculative. Inconsistent findings and methodological limitations within research (e.g. programme design, sampling period, number of samples) make interpretation further difficult. We contend that strength and power research needs to investigate those metabolic mechanisms likely to contribute to weight-training adaptation. Further research is also needed to examine the metabolic responses to different loading schemes, as well as interactions across age, sex and training status, so our understanding of how to optimise strength and power development is improved.

  6. The Association between Maximal Bench Press Strength and Isometric Handgrip Strength among Breast Cancer Survivors

    Science.gov (United States)

    Rogers, Benjamin H.; Brown, Justin C.; Gater, David R.; Schmitz, Kathryn H.

    2016-01-01

    Objective One-repetition maximum (1-RM) bench press strength is considered the gold standard to quantify upper-body muscular strength. Isometric handgrip strength is frequently used as a surrogate for 1-RM bench press strength among breast cancer (BrCa) survivors. The relationship between 1-RM bench press strength and isometric handgrip strength, however, has not been characterized among BrCa survivors. Design Cross-sectional study. Setting Laboratory. Participants Community-dwelling BrCa survivors. Interventions Not applicable. Main Outcome Measure 1-RM bench press strength was measured with a barbell and exercise bench. Isometric handgrip strength was measured using an isometric dynamometer with three maximal contractions of left and right hands. All measures were conducted by staff with training in clinical exercise testing. Results Among 295 BrCa survivors, 1-RM bench press strength was 18.2±6.1 kg (range: 2.2-43.0) and isometric handgrip strength was 23.5±5.8 kg (range: 9.0-43.0). The strongest correlate of 1-RM bench press strength was the average isometric handgrip strength of both hands (r=0.399; Pisometric handgrip strength of both hands overestimated 1-RM bench press strength by 4.7 kg (95% limits of agreement: −8.2 to 17.6). In a multivariable linear regression model, the average isometric handgrip strength of both hands (β=0.31; Pstrength (R2=0.23). Conclusions Isometric handgrip strength is a poor surrogate for 1-RM bench press strength among BrCa survivors. 1-RM bench press and isometric handgrip strength quantify distinct components of muscular strength. PMID:27543047

  7. Experimental and simulated strength of spot welds

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Bennedbæk, Rune A.K.; Larsen, Morten B.

    2014-01-01

    Weld strength testing of single spots in DP600 steel is presented for the three typical testing procedures, i.e. tensile-shear, cross-tension and peel testing. Spot welds are performed at two sets of welding parameters and strength testing under these conditions is presented by load......-elongation curves revealing the maximum load and the elongation at break. Welding and strength testing is simulated by SORPAS® 3D, which allows the two processes to be prepared in a combined simulation, such that the simulated welding properties are naturally applied to the simulation of strength testing. Besides...... the size and shape of the weld nugget, these properties include the new strength of the material in the weld and the heat affected zone based on the predicted hardness resulting from microstructural phase changes simulated during cooling of the weld before strength testing. Comparisons between overall...

  8. Elastic stability and the limit of strength

    International Nuclear Information System (INIS)

    Morris Jr., J.W.; Krenn, C.R.; Roundy, D.; Cohen, Marvin L.

    2002-01-01

    The upper limit of strength (the ''theoretical strength'') has been an active subject of research and speculation for the better part of a century. The subject has recently become important, for two reasons. First, given recent advances in ab initio techniques and computing machines, the limits of strength can be calculated with considerable accuracy, making this one of the very few problems in mechanical behavior that can actually be solved. Second, given recent advances in materials engineering, the limits of strength are being approached in some systems, such as hardened or defect-free films, and their relevance is becoming recognized in others. The present paper discusses some interesting results from recent research on the limits of strength, with an intermixture of speculations based on those results. Topics include the inherent nature of {100} cleavage and ''pencil slip'' in bcc metals, the inherent ductility of fcc metals, the anomalous properties of Al, and the possibility of measuring ideal strength with nanoindentation

  9. Prediction of concrete strength in massive structures

    International Nuclear Information System (INIS)

    Sakamoto, T.; Makino, H.; Nakane, S.; Kawaguchi, T.; Ohike, T.

    1989-01-01

    Reinforced concrete structures of a nuclear power plant are mostly of mass concrete with cross-sectional dimensions larger than 1.0 m. The temperature of concrete inside after placement rises due to heat of hydration of cement. It is well known that concrete strengths of mass concrete structure subjected to such temperature hysteresis are generally not equal to strengths of cylinders subjected to standard curing. In order to construct a mass concrete structure of high reliability in which the specified concrete strength is satisfied by the specified age, it is necessary to have a thorough understanding of the strength gain property of concrete in the structure and its relationships with the water-cement ratio of the mix, strength of standard-cured cylinders and the internal temperature hysteresis. This report describes the result of studies on methods of controlling concrete strength in actual construction projects

  10. Experimental knee pain reduces muscle strength

    DEFF Research Database (Denmark)

    Henriksen, Marius; Mortensen, Sara Rosager; Aaboe, Jens

    2011-01-01

    Pain is the principal symptom in knee pathologies and reduced muscle strength is a common observation among knee patients. However, the relationship between knee joint pain and muscle strength remains to be clarified. This study aimed at investigating the changes in knee muscle strength following...... experimental knee pain in healthy volunteers, and if these changes were associated with the pain intensities. In a crossover study, 18 healthy subjects were tested on 2 different days. Using an isokinetic dynamometer, maximal muscle strength in knee extension and flexion was measured at angular velocities 0....... Knee pain reduced the muscle strength by 5 to 15% compared to the control conditions (P knee extension and flexion at all angular velocities. The reduction in muscle strength was positively correlated to the pain intensity. Experimental knee pain significantly reduced knee extension...

  11. TOUGHREACT Testing in High Ionic Strength Brine Sandstone Systems

    International Nuclear Information System (INIS)

    Xu, Tianfu

    2008-01-01

    Deep saline formations and oil and gas reservoirs often contain concentrated brine solutions of ionic strength greater than 1 (I > 1 M). Geochemical modeling, involving high ionic strength brines, is a challenge. In the original TOUGHREACT code (Xu et al., 2004; Xu et al., 2006), activity coefficients of charged aqueous species are computed using an extended Debye-Huckel (DH) equation and parameters derived by Helgeson et al. (1981). The DH model can deal with ionic strengths from dilute to moderately saline water (up to 6 molal for an NaCl-dominant solution). The equations implemented for the DH model are presented in Appendix A. During the course of the Yucca Mountain project, a Pitzer ion-interaction model was implemented into TOUGHREACT. This allows the application of this simulator to problems involving much more concentrated aqueous solutions, such as those involving geochemical processes in and around high-level nuclear waste repositories where fluid evaporation and/or boiling is expected to occur (Zhang et al., 2007). The Pitzer ion-interaction model, which we refer to as the Pitzer virial approach, and associated ion-interaction parameters have been applied successfully to study non-ideal concentrated aqueous solutions. The formulation of the Pitzer model is presented in Appendix B; detailed information can be founded in Zhang et al. (2007). For CO 2 geological sequestration, the Pitzer ion-interaction model for highly concentrated brines was incorporated into TOUGHREACT/ECO2N, then was tested and compared with a previously implemented extended Debye-Hueckel (DH) ion activity model. The comparison was made through a batch geochemical system using a Gulf Coast sandstone saline formation

  12. The reliabilty of isokinetic strength measurement

    OpenAIRE

    Kadlec, Miroslav

    2011-01-01

    Title: Reliability of isometric and isokinetic strength testing in the knee flexion and extension Objectives: To compare the reliability of isometric and isokinetic testing of the knee strength in flexion and extension Methods: I used intraclass correlation coefficient and Pearson's correlation coefficient. Results: I have discovered that the reliability measured on isokinetic and isometric dynamometer is high. Furthermore the reliability of the maximum strength measurement was higher with-us...

  13. Strength and failure modes of ceramic multilayers

    DEFF Research Database (Denmark)

    Sørensen, Bent F.; Toftegaard, Helmuth Langmaack; Linderoth, Søren

    2012-01-01

    A model was developed for the prediction of the tensile strength of thin, symmetric 3-layer sandwich specimens. The model predictions rationalize the effect of heat-treatment temperature on the strength of sandwich specimens consisting of an YSZ (Yttria-Stabilized Zirconia) substrate coated with ...... and propagating into the substrate. These predictions are consistent with microstructural observations of the fracture surfaces. A good agreement was found between the measured strength values and model predictions. © 2012 Elsevier Ltd. All rights reserved....

  14. Accounting for the Strengths of MNC Subsidiaries

    DEFF Research Database (Denmark)

    Forsgren, Mats; Pedersen, Torben; Foss, Nicolai Juul

    1999-01-01

    that organizational strength can to some extent be proxied by strength in the market place. Based on analysis of data on foreign-owned production firms in Denmark, we test three hypotheses: 1) that internal factors (capabilities, patents....) are positively related to the organizational strengths of MNC subsidiaries......This paper links up with recent work on the role of subsidiaries in multinational corporations as well as with recent work in the strategy and business network literature. We discuss the sources of organizational strengths of subsidiaries in the larger multinational corporation, and argue...

  15. Accelerated Strength Testing of Thermoplastic Composites

    Science.gov (United States)

    Reeder, J. R.; Allen, D. H.; Bradley, W. L.

    1998-01-01

    Constant ramp strength tests on unidirectional thermoplastic composite specimens oriented in the 90 deg. direction were conducted at constant temperatures ranging from 149 C to 232 C. Ramp rates spanning 5 orders of magnitude were tested so that failures occurred in the range from 0.5 sec. to 24 hrs. (0.5 to 100,000 MPa/sec). Below 204 C, time-temperature superposition held allowing strength at longer times to be estimated from strength tests at shorter times but higher temperatures. The data indicated that a 50% drop in strength might be expected for this material when the test time is increased by 9 orders of magnitude. The shift factors derived from compliance data applied well to the strength results. To explain the link between compliance and strength, a viscoelastic fracture model was investigated. The model, which used compliance as input, was found to fit the strength data only if the critical fracture energy was allowed to vary with temperature reduced stress rate. This variation in the critical parameter severely limits its use in developing a robust time-dependent strength model. The significance of this research is therefore seen as providing both the indication that a more versatile acceleration method for strength can be developed and the evidence that such a method is needed.

  16. Shear strength of end slabs of prestressed concrete reactor vessels

    International Nuclear Information System (INIS)

    Cheung, K.C.; Gotschall, H.L.; Liu, T.C.

    1975-01-01

    Prestressed concrete reactor vessels (PCRV's) have been adopted for primary containments in most large high-temperature gas-cooled reactor installations. The most common configuration for PCRVs is a right-vertical cylinder with thick end slabs. In order to assess the integrity of a PCRV it is necessary to predict the ultimate strength of the end slabs. The complexity of the basic mechanism of shear failure in the PCRV end slabs has thus far prohibited the development of a completely analytical solution. However, many experimental investigations of PCRV end slabs have been conducted over the past decade. This information makes it possible to establish empirical formulae for the ultimate strength of PCRV end slabs. The basis and development of an empirical shear-flexure interaction expression is presented. (Auth.)

  17. Compressive strength of brick masonry made with weak mortars

    DEFF Research Database (Denmark)

    Pedersen, Erik Steen; Hansen, Klavs Feilberg

    2013-01-01

    in the joint will ensure a certain level of load-carrying capacity. This is due to the interaction between compression in the weak mortar and tension in the adjacent bricks. This paper proposes an expression for the compressive strength of masonry made with weak lime mortars (fm... of masonry depends only on the strength of the bricks. A compression failure in masonry made with weak mortars occurs as a tension failure in the bricks, as they seek to prevent the mortar from being pressed out of the joints. The expression is derived by assuming hydrostatic pressure in the mortar joints......, which is the most unfavourable stress distribution with respect to tensile stresses in bricks. The expression is compared with the results of compression tests of masonry made with weak mortars. It can take into account bricks with arbitrary dimensions as well as perforated bricks. For a stronger mortar...

  18. Chemical composition and strength of dolomite geopolymer composites

    Science.gov (United States)

    Aizat, E. A.; Al Bakri, A. M. M.; Liew, Y. M.; Heah, C. Y.

    2017-09-01

    The chemical composition of dolomite and the compressive strength of dolomite geopolymer composites were studied. The both composites prepared with mechanical mixer manufactured by with rotor speed of 350 rpm and curing in the oven for 24 hours at 80˚C. XRF analysis showThe dolomite raw materials contain fewer amounts of Si and Al but high Ca in its composition. Dolomite geopolymer composites with 20M of NaOH shows greater and optimum compressive strength compared to dolomite geopolymer with other NaOH molarity. This indicated better interaction of dolomite raw material and alkaline activator need high molarity of NaOH in order to increase the reactivity of dolomite.

  19. Uniaxial Compressive Strengths of Rocks Drilled at Gale Crater, Mars

    Science.gov (United States)

    Peters, G. H.; Carey, E. M.; Anderson, R. C.; Abbey, W. J.; Kinnett, R.; Watkins, J. A.; Schemel, M.; Lashore, M. O.; Chasek, M. D.; Green, W.; Beegle, L. W.; Vasavada, A. R.

    2018-01-01

    Measuring the physical properties of geological materials is important for understanding geologic history. Yet there has never been an instrument with the purpose of measuring mechanical properties of rocks sent to another planet. The Mars Science Laboratory (MSL) rover employs the Powder Acquisition Drill System (PADS), which provides direct mechanical interaction with Martian outcrops. While the objective of the drill system is not to make scientific measurements, the drill's performance is directly influenced by the mechanical properties of the rocks it drills into. We have developed a methodology that uses the drill to indicate the uniaxial compressive strengths of rocks through comparison with performance of an identically assembled drill system in terrestrial samples of comparable sedimentary class. During this investigation, we utilize engineering data collected on Mars to calculate the percussive energy needed to maintain a prescribed rate of penetration and correlate that to rock strength.

  20. Effect of the conditions of prepreg preparation on the strength of structural plastics

    Science.gov (United States)

    Zaborskaya, L. V.; Yurkevich, O. R.

    1995-05-01

    A study is made of the effect of the temperature and duration of heat treatment of polymer composite prepregs on their strength. It is established that heat treatment under conditions ensuring close to maximal adhesive interaction between the components of the prepreg and subsequent shaping makes it possible to more than double the strength of the plastic (Table 1), A new approach is proposed to optimizing the conditions of formation of structural plastics.

  1. Professional development themes in strength and conditioning coaches.

    Science.gov (United States)

    Tod, David A; Bond, Kath A; Lavallee, David

    2012-03-01

    The purpose of this study was to explore professional development themes in experienced strength and conditioning coaches. Strength and conditioning coaches (N = 15, mean age = 34.3 years, SD = 5.2 years) with 11.4 (SD = 4.9) years experience working with elite, professional, or talented athletes were interviewed about their professional development. The interviews were transcribed verbatim and content analyzed. Over time, subjects' service-delivery practices became more flexible and client driven. Their role understanding also broadened to include various dimensions, such as the need to consider various stakeholders and the value of good relationships with athletes. The subjects shifted from relying on external justification for professional decision making to their experience-based knowledge. The subjects believed athlete work experience, interactions with senior strength and conditioning coaches and other colleagues, the professional literature, and nonprofessional experiences, such as their own athletic experience and sales or managerial training, were the primary influences on their professional development. Typically, the subjects experienced anxiety about their competence, both early in their careers and when working in new contexts or with new athlete groups, but over time, they developed increased confidence. In addition, the subjects experienced reduced narcissism over time about the control they had over athletes and their competitive results. The current results provide information about the characteristics of effective strength and conditioning coaches, the ways they develop their competencies to help athletes, and the emotions they experience throughout their careers. These results may help strength and conditioning practitioners in planning and optimizing their professional development and effectiveness with athletes.

  2. Interacting hot dark matter

    International Nuclear Information System (INIS)

    Atrio-Barandela, F.; Davidson, S.

    1997-01-01

    We discuss the viability of a light particle (∼30eV neutrino) with strong self-interactions as a dark matter candidate. The interaction prevents the neutrinos from free-streaming during the radiation-dominated regime so galaxy-sized density perturbations can survive. Smaller scale perturbations are damped due to neutrino diffusion. We calculate the power spectrum in the imperfect fluid approximation, and show that it is damped at the length scale one would estimate due to neutrino diffusion. The strength of the neutrino-neutrino coupling is only weakly constrained by observations, and could be chosen by fitting the power spectrum to the observed amplitude of matter density perturbations. The main shortcoming of our model is that interacting neutrinos cannot provide the dark matter in dwarf galaxies. copyright 1997 The American Physical Society

  3. Strengths-Based Approaches in College and University Student Housing: Implications for First-Year Students' Retention and Engagement

    Science.gov (United States)

    Soria, Krista M.; Taylor, Leonard, Jr.

    2016-01-01

    Strengths-based approaches are expanding in higher education; however, little is known about the impacts of these approaches in housing and residence life settings. The purpose of this study was to examine the associations between first-year students' strengths interactions in housing and their engagement and retention. The results suggest that…

  4. The Relation between Degree and Strength in the Complex Network Derived from an Individual Stock

    Directory of Open Access Journals (Sweden)

    Zelin Zhang

    2016-01-01

    Full Text Available A method based on coarse-graining to construct a directed weighted complex network which models the transformation of the trading data of an individual stock is introduced. The degree (strength distribution of derived network follows a power-law. A moderated regression equation with interaction effects of average return and out-degree (in-degree on out-strength (in-strength is established. Moreover, we found that the differences of nodes affect the network’s structure and average return level impacts nodes’ eigenvector centrality and pagerank, significantly.

  5. Atomic structure calculation of energy levels and oscillator strengths in Ti ion, 2

    International Nuclear Information System (INIS)

    Ishii, Keishi

    1983-10-01

    Energy levels and oscillator strengths are calculated for 3s-3p and 3p-3d transition arrays in Ti X, isoelectronic to Al I. The energy levels are obtained by the Slater-Condon theory of atomic structure, including explicitly the strong configuration interactions. The results are presented both in numerical tables and in diagrams. In the tables, the observed data are included for comparison, where available. The calculated weighted oscillator strengths (gf-value) are also displayed in figures, where the weighted oscillator strengths are plotted as a function of wavelength. (author)

  6. The Relative Hydrogen Bonding Strength of Oxygen and Nitrogen Atoms as a Proton Acceptor

    International Nuclear Information System (INIS)

    Hyun, Jong Cheol; Lee, Ho Jin; Kim, Nak Kyoon; Choi, Young Sang; Park, Jeung Hee; Yoon, Chang Ju

    1999-01-01

    The thermodynamic parameters for the formation of the hydrogen bonding were widely used to understand the protein- ligand interaction. We have been interested in the hydrogen bonding strength of various proton acceptors toward the amide in a nonpolar solvent, This work is in the line of our interest. In drug design, the functional group is often replaced in order to enhance or reduce the binding affinity, which is usually determined by hydrogen bonding strength. Therefore, to understand this biochemical process the knowledge of relative hydrogen bonding strength is of importance.

  7. Revealing the Maximum Strength in Nanotwinned Copper

    DEFF Research Database (Denmark)

    Lu, L.; Chen, X.; Huang, Xiaoxu

    2009-01-01

    boundary–related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced...

  8. Maximal Strength Testing in Healthy Children.

    Science.gov (United States)

    Faigenbaum, Avery D.; Milliken, Laurie A.; Westcott, Wayne L.

    2003-01-01

    Evaluated the safety and efficacy of 1 repetition maximum (1RM) strength testing in healthy children age 6-12 years. Data were collected on 96 children who performed a 1RM test on one upper body and one lower body exercise using child-sized weight machines. Findings indicated that children could safely perform 1RM strength tests provided…

  9. Impact of Hydrodynamics on Oral Biofilm Strength

    NARCIS (Netherlands)

    Paramonova, E.; Kalmykowa, O. J.; van der Mei, H. C.; Busscher, H. J.; Sharma, P. K.

    2009-01-01

    Mechanical removal of oral biofilms is ubiquitously accepted as the best way to prevent caries and periodontal diseases. Removal effectiveness strongly depends on biofilm strength. To investigate the influence of hydrodynamics on oral biofilm strength, we grew single- and multi-species biofilms of

  10. Crushing strength of HTGR fuel particles

    International Nuclear Information System (INIS)

    Lackey, W.J.; Stinton, D.P.; Davis, L.E.; Beatty, R.L.

    1976-01-01

    The whole-particle crushing strengths of High-Temperature Gas-Cooled Reactor fertile and fissile coated particles were measured and correlated with fabrication procedures. The crushing strength of Biso-coated fertile particles was increased by the following factors: (1) increasing the outer coating thickness by 10 μm increased strengths by 0.3 lb (1.3 N) for annealed particles and by 0.5 lb (2.2 N) for unannealed particles. (2) An 1800 0 C postcoating anneal increased strengths by 1 lb (4.4 N) for particles with thick outer coatings and by 2 lb (8.9 N) for particles having thin coatings. (3) Increasing the inner coating density by 0.1 g/cm 3 increased strength by 0.6 lb (2.7 N). The crushing strength of Triso-coated fissile particles was proportional to the thickness of the SiC coatings, and strength decreased on annealing by about 0.2 lb (0.9 N) when a porous plate was used to distribute the coating gas and by about 1.5 lb (6.7 N) when a conical gas distributor was used. The strengths of fertile and fissile coated particles as well as uncoated kernels appear adequate to allow fuel fabrication without excessive particle damage

  11. Tools for Building on Youth Strengths

    Science.gov (United States)

    Cox, Kathy

    2008-01-01

    While rhetoric about strength-based approaches abounds, this perspective has not penetrated the front lines of practice. Many programs serving troubled youngsters are still mired in a deficit and deviance orientation. This article provides practical strategies for assessing the strengths of children and developing interventions to tap their assets…

  12. Restorative Justice as Strength-Based Accountability

    Science.gov (United States)

    Ball, Robert

    2003-01-01

    This article compares strength-based and restorative justice philosophies for young people and their families. Restorative justice provides ways to respond to crime and harm that establish accountability while seeking to reconcile members of a community. Restorative approaches are an important subset of strength-based interventions.

  13. Asymmetry of Muscle Strength in Elite Athletes

    Science.gov (United States)

    Drid, Patrik; Drapsin, Miodrag; Trivic, Tatjana; Lukac, Damir; Obadov, Slavko; Milosevic, Zoran

    2009-01-01

    "Study aim": To determine muscle strength variables in elite judoists and wrestlers since thigh muscle strength and bilaterally balanced flexor-to-extensor ratio minimise injury risk and are desirable for achieving sport successes. "Material and methods": Judoists, wrestlers and untrained subjects, 10 each, were subjected to isokinetic strength…

  14. Gluebond strength of laser cut wood

    Science.gov (United States)

    Charles W. McMillin; Henry A. Huber

    1985-01-01

    The degree of strength loss when gluing laser cut wood as compared to conventionally sawn wood and the amount of additional surface treatment needed to improve bond quality were assessed under normal furniture plant operating conditions. The strength of laser cut oak glued with polyvinyl acetate adhesive was reduced to 75 percent of sawn joints and gum was reduced 43...

  15. Enhancing paper strength by optimizing defect configuration

    Science.gov (United States)

    J.M. Considine; W. Skye; W. Chen; D. Matthys; David W. Vahey; K. Turner; R. Rowlands

    2009-01-01

    Poor formation in paper, as denoted by large local variation of mass, tends to reduce maximum tensile strength but has not been well characterized. The effect of grammage variation on tensile strength was studied by introducing carefully placed holes in tensile specimens made of three different paper materials. Previous researchers demonstrated that the point-stress...

  16. Strength optimized designs of thermoelastic structures

    DEFF Research Database (Denmark)

    Pedersen, Pauli; Pedersen, Niels Leergaard

    2010-01-01

    For thermoelastic structures the same optimal design does not simultaneously lead to minimum compliance and maximum strength. Compliance may be a questionable objective and focus for the present paper is on the important aspect of strength, quantified as minimization of the maximum von Mises stre...... loads are appended....

  17. Buckling strength of spherical shells under combined loads

    International Nuclear Information System (INIS)

    Nagashima, H.; Kokubo, K.; Takayanagi, M.; Hayasaka, Y.; Kume, T.; Nagata, T.

    1995-01-01

    Many studies on buckling of cylindrical shells have been conducted, and many buckling evaluation equations have been proposed for actual plant designs; however, buckling of spherical shells under combined horizontal and vertical loads cannot be evaluated due to insufficient data. There is a particular lack of buckling data for spherical shells under lateral loads. To establish a method for estimating the buckling strength of spherical shells, we investigate the interactions between horizontal and vertical (compressive tensile) loads by conducting buckling tests. Applying several combinations of these loads in tests and using computer linear analysis, we obtain interaction curves. This study reports on the buckling tests conducted using spherical shell 1120 mm in dia., 0.7 mm thick and 696 mm high, which are shaped individually by press-forming and finally joined together by four meridional welds, using a specially made jig. Initial imperfections before testing and local deformations after each loading increment during testing are measured with special measuring equipment, and the interaction curve of horizontal and vertical loads and effect of imperfection on the buckling strength of spherical shells are obtained. Nonlinear FEM programs are developed using an 8-node isoparametric shell element and a four-node quadrilateral element of C 0 type with reduced integration based upon a Mindlin-Reissner theory which includes transverse shear. Actual initial imperfections are generally in irregular patterns. Thus, there may be several definitions of the equivalent magnitudes of initial imperfections related to buckling loads. Equivalent magnitudes have no practical meaning unless they can be obtained easily not only for small structures such as test shells but also for large actual structures. In the present study, we define the equivalent magnitude of initial imperfections as the maximum local ruggedness measured radially from a circular temperature having a radius equal

  18. The order parameters of a spin-1 Ising film in a transverse field

    International Nuclear Information System (INIS)

    Saber, A.; Ainane, A.; Dujardin, F.; Saber, M.; Stebe, B.

    1998-08-01

    Using the effective field theory with a probability distribution technique that accounts for the self-spin correlation functions, the layer longitudinal magnetizations and quadrupolar moments of a spin-1 Ising film and their averages are examined. These quantities as functions of the temperature, the ratio of the surface exchange interactions to the bulk ones, the strength of the transverse field and the film thickness are calculated numerically and some interesting results are obtained. (author)

  19. SOLID BURNT BRICKS’ TENSILE STRENGTH

    Directory of Open Access Journals (Sweden)

    Aneta Maroušková

    2017-11-01

    Full Text Available This paper deals with experimental testing of solid burnt bricks and mortar in pure (axial tension. The obtained working diagrams will be further use for a detailed numerical analysis of whole brick masonry column under concentric compressive load. Failure mechanism of compressed brick masonry column is characterized by the appearance and development of vertical tensile cracks in masonry units (bricks passing in the direction of principal stresses and is accompanied by progressive growth of horizontal deformations. These cracks are caused by contraction and interaction between two materials with different mechanical characteristics (brick and mortar. The aim of this paper is more precisely describe the response of quasi-brittle materials to uniaxial loading in tension (for now only the results from three point bending test are available. For these reasons, bricks and mortar tensile behavior is experimentally tested and the obtained results are discussed.

  20. Nuclear threshold effects and neutron strength function

    International Nuclear Information System (INIS)

    Hategan, Cornel; Comisel, Horia

    2003-01-01

    One proves that a Nuclear Threshold Effect is dependent, via Neutron Strength Function, on Spectroscopy of Ancestral Neutron Threshold State. The magnitude of the Nuclear Threshold Effect is proportional to the Neutron Strength Function. Evidence for relation of Nuclear Threshold Effects to Neutron Strength Functions is obtained from Isotopic Threshold Effect and Deuteron Stripping Threshold Anomaly. The empirical and computational analysis of the Isotopic Threshold Effect and of the Deuteron Stripping Threshold Anomaly demonstrate their close relationship to Neutron Strength Functions. It was established that the Nuclear Threshold Effects depend, in addition to genuine Nuclear Reaction Mechanisms, on Spectroscopy of (Ancestral) Neutron Threshold State. The magnitude of the effect is proportional to the Neutron Strength Function, in their dependence on mass number. This result constitutes also a proof that the origins of these threshold effects are Neutron Single Particle States at zero energy. (author)

  1. Imaging Shear Strength Along Subduction Faults

    Science.gov (United States)

    Bletery, Quentin; Thomas, Amanda M.; Rempel, Alan W.; Hardebeck, Jeanne L.

    2017-11-01

    Subduction faults accumulate stress during long periods of time and release this stress suddenly, during earthquakes, when it reaches a threshold. This threshold, the shear strength, controls the occurrence and magnitude of earthquakes. We consider a 3-D model to derive an analytical expression for how the shear strength depends on the fault geometry, the convergence obliquity, frictional properties, and the stress field orientation. We then use estimates of these different parameters in Japan to infer the distribution of shear strength along a subduction fault. We show that the 2011 Mw9.0 Tohoku earthquake ruptured a fault portion characterized by unusually small variations in static shear strength. This observation is consistent with the hypothesis that large earthquakes preferentially rupture regions with relatively homogeneous shear strength. With increasing constraints on the different parameters at play, our approach could, in the future, help identify favorable locations for large earthquakes.

  2. Testosterone Replacement, Muscle Strength, and Physical Function

    Directory of Open Access Journals (Sweden)

    You-Seon Nam

    2018-05-01

    Full Text Available Muscle strength and physical function decrease in older men, as do testosterone levels. Nonetheless, the effects of testosterone replacement therapy on muscle strength and physical function remain inconclusive and equivocal. We conducted a rapid systematic review, the results of which showed that testosterone replacement does not affect muscle strength (measured by hand grip strength and leg muscle strength, although it may increase physical function (measured by the 6-minute walk test, Physical Activity Scale for the Elderly score, and other physical performance tests. However, most of the studies were conducted in the United States or Europe and did not include participants from Asian or other ethnic backgrounds; therefore, further studies are needed to evaluate the effects of testosterone replacement in a broader population.

  3. REPETITIVE STRENGTH AMONG STUDENTS OF AGE 14

    Directory of Open Access Journals (Sweden)

    Besim Halilaj

    2014-06-01

    Full Text Available The study involved 82 male students of the primary school “Qamil Ilazi” in Kaçanik-Kosovo.Four movement tests, which test the repetitive strength, were conducted: 1. Pull-up, 2. Sit-Up, 3. Back extension, 4. Push-up.The main goal of this study was to verify the actual motor status, respectively the component of the repetitive strength among students of age 14 of masculine gender. In addition to verifying the actual motor status, another objective was to verify the relationship between the variables employed.Basic statistical parameters show a distribution which is not significantly different from the normal distribution, yielded highly correlative values among the repetitive strength tests. Space factorization resulted in extracting two latent squares defined as repetitive strength of arms factor, and repetitive strength of body factor.

  4. Imaging shear strength along subduction faults

    Science.gov (United States)

    Bletery, Quentin; Thomas, Amanda M.; Rempel, Alan W.; Hardebeck, Jeanne L.

    2017-01-01

    Subduction faults accumulate stress during long periods of time and release this stress suddenly, during earthquakes, when it reaches a threshold. This threshold, the shear strength, controls the occurrence and magnitude of earthquakes. We consider a 3-D model to derive an analytical expression for how the shear strength depends on the fault geometry, the convergence obliquity, frictional properties, and the stress field orientation. We then use estimates of these different parameters in Japan to infer the distribution of shear strength along a subduction fault. We show that the 2011 Mw9.0 Tohoku earthquake ruptured a fault portion characterized by unusually small variations in static shear strength. This observation is consistent with the hypothesis that large earthquakes preferentially rupture regions with relatively homogeneous shear strength. With increasing constraints on the different parameters at play, our approach could, in the future, help identify favorable locations for large earthquakes.

  5. Spin-orbit interaction driven dimerization in one dimensional frustrated magnets

    Science.gov (United States)

    Zhang, Shang-Shun; Batista, Cristian D.

    Spin nematic ordering has been proposed to emerge near the saturation of field of a class of frustrated magnets. The experimental observation of this novel phase is challenging for the traditional experimental probes. Nematic spin ordering is expected to induce a local quadrupolar electric moment via the spin-orbit coupling. However, a finite spin-orbit interaction explicitly breaks the U(1) symmetry of global spin rotations down to Z2, which renders the traditional nematic order no longer well-defined. In this work we investigate the relevant effect of spin-orbit interaction on the 1D frustrated J1 -J2 model. The real and the imaginary parts of the nematic order parameter belong to different representations of the discrete symmetry group of the new Hamiltonian. We demonstrate that spin-orbit coupling stabilizes the real component and simultaneously induces bond dimerization in most of the phase diagram. Such a bond dimerization can be observed with X-rays or nuclear magnetic resonance. In addition, an incommensurate bond-density wave (ICBDW) appears for smaller values of J2 / |J1 | . The experimental fingerprint of the ICBDW is a double-horn shape of the the NMR line. These conclusions can shed light on the experimental search of this novel phase.

  6. Wetting, meniscus structure, and capillary interactions of microspheres bound to a cylindrical liquid interface.

    Science.gov (United States)

    Kim, Paul Y; Dinsmore, Anthony D; Hoagland, David A; Russell, Thomas P

    2018-03-14

    Wetting, meniscus structure, and capillary interactions for polystyrene microspheres deposited on constant curvature cylindrical liquid interfaces, constructed from nonvolatile ionic or oligomeric liquids, were studied by optical interferometry and optical microscopy. The liquid interface curvature resulted from the preferential wetting of finite width lines patterned onto planar silicon substrates. Key variables included sphere diameter, nominal (or average) contact angle, and deviatoric interfacial curvature. Menisci adopted the quadrupolar symmetry anticipated by theory, with interfacial deformation closely following predicted dependences on sphere diameter and nominal contact angle. Unexpectedly, the contact angle was not constant locally around the contact line, the nominal contact angle varied among seemingly identical spheres, and the maximum interface deviation did not follow the predicted dependence on deviatoric interfacial curvature. Instead, this deviation was up to an order-of-magnitude larger than predicted. Trajectories of neighboring microspheres visually manifested quadrupole-quadrupole interactions, eventually producing square sphere packings that foreshadow interfacial assembly as a potential route to hierarchical 2D particle structures.

  7. Experimental knee joint pain during strength training and muscle strength gain in healthy subjects

    DEFF Research Database (Denmark)

    Sørensen, T J; Langberg, Henning; Hodges, P W

    2012-01-01

    Knee joint pain and reduced quadriceps strength are cardinal symptoms in many knee pathologies. In people with painful knee pathologies, quadriceps exercise reduces pain, improves physical function, and increases muscle strength. A general assumption is that pain compromises muscle function...... and thus may prevent effective rehabilitation. This study evaluated the effects of experimental knee joint pain during quadriceps strength training on muscle strength gain in healthy individuals....

  8. Percentage Level of Tannin fur Rabbit for Leather Concerning Stitch Tearing Strength, Tearing Strength and Flexibility

    OpenAIRE

    Mustakim Mustakim; Aris Sri Widati; Lisa Purnaningtyas

    2012-01-01

    The purpose of this study was to find out the appropriate of tannin level for rabbit fur leather concerning stitch tearing strength, tearing strength, and flexibility. The result were expected to contribute good information for the society, leather craftsman, and further researchers about fur leather tanning especially rabbit fur leather with tannin concerning stitch tearing strength, tearing strength and flexibility. The material that used were 12 pieces of four months of rabbit skin. The re...

  9. Development of K-Basin High-Strength Homogeneous Sludge Simulants and Correlations Between Unconfined Compressive Strength and Shear Strength

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Yasuo; Baer, Ellen BK; Chun, Jaehun; Yokuda, Satoru T.; Schmidt, Andrew J.; Sande, Susan; Buchmiller, William C.

    2011-02-20

    K-Basin sludge will be stored in the Sludge Transport and Storage Containers (STSCs) at an interim storage location on Central Plateau before being treated and packaged for disposal. During the storage period, sludge in the STSCs may consolidate/agglomerate, potentially resulting in high-shear-strength material. The Sludge Treatment Project (STP) plans to use water jets to retrieve K-Basin sludge after the interim storage. STP has identified shear strength to be a key parameter that should be bounded to verify the operability and performance of sludge retrieval systems. Determining the range of sludge shear strength is important to gain high confidence that a water-jet retrieval system can mobilize stored K-Basin sludge from the STSCs. The shear strength measurements will provide a basis for bounding sludge properties for mobilization and erosion. Thus, it is also important to develop potential simulants to investigate these phenomena. Long-term sludge storage tests conducted by Pacific Northwest National Laboratory (PNNL) show that high-uranium-content K-Basin sludge can self-cement and form a strong sludge with a bulk shear strength of up to 65 kPa. Some of this sludge has 'paste' and 'chunks' with shear strengths of approximately 3-5 kPa and 380-770 kPa, respectively. High-uranium-content sludge samples subjected to hydrothermal testing (e.g., 185 C, 10 hours) have been observed to form agglomerates with a shear strength up to 170 kPa. These high values were estimated by measured unconfined compressive strength (UCS) obtained with a pocket penetrometer. Due to its ease of use, it is anticipated that a pocket penetrometer will be used to acquire additional shear strength data from archived K-Basin sludge samples stored at the PNNL Radiochemical Processing Laboratory (RPL) hot cells. It is uncertain whether the pocket penetrometer provides accurate shear strength measurements of the material. To assess the bounding material strength and

  10. The Character Strengths of Class Clowns

    Directory of Open Access Journals (Sweden)

    Willibald F. Ruch

    2014-09-01

    Full Text Available Class clowns traditionally were studied as a type concept and identified via sociometric procedures. In the present study a variable-centered approach was favored and class clown behaviors were studied in the context of character strengths, orientations to happiness and satisfaction with life. A sample of 672 Swiss children and adolescents filled in an 18 item self-report instrument depicting class clown behaviors. A hierarchical model of class clown behaviors was developed distinguishing a general factor and the four positively correlated dimensions of identified as a class clown, comic talent, disruptive rule-breaker, and subversive joker. Analysis of the general factor showed that class clowns were primarily male, and tended to be seen as class clowns by the teacher. Analyses of the 24 character strengths of the VIA-Youth (Park & Peterson, 2006 showed that class clowns were high in humor and leadership, and low in strengths like prudence, self-regulation, modesty, honesty, fairness, perseverance, and love of learning. An inspection of signature strengths revealed that 75% of class clowns had humor as a signature strength. Furthermore, generally class clown behaviors were shown by students indulging in a life of pleasure, but low life of engagement. The four dimensions yielded different character strengths profiles. While all dimensions of class clowns behaviors were low in temperance strengths, the factors identified as the class clown and comic talent were correlated with leadership strengths and the two negative factors (disruptive rule-breaker, subversive joker were low in other directed strengths. The disruptive rule breaking class clown was additionally low in intellectual strengths. While humor predicted life satisfaction, class clowning tended to go along with diminished satisfaction with life. It is concluded that different types of class clowns need to be kept apart and need different attention by teachers.

  11. The character strengths of class clowns.

    Science.gov (United States)

    Ruch, Willibald; Platt, Tracey; Hofmann, Jennifer

    2014-01-01

    Class clowns traditionally were studied as a type concept and identified via sociometric procedures. In the present study a variable-centered approach was favored and class clown behaviors were studied in the context of character strengths, orientations to happiness and satisfaction with life. A sample of 672 Swiss children and adolescents filled in an 18 item self-report instrument depicting class clown behaviors. A hierarchical model of class clown behaviors was developed distinguishing a general factor and the four positively correlated dimensions of "identified as a class clown," "comic talent," "disruptive rule-breaker," and "subversive joker." Analysis of the general factor showed that class clowns were primarily male, and tended to be seen as class clowns by the teacher. Analyses of the 24 character strengths of the VIA-Youth (Park and Peterson, 2006) showed that class clowns were high in humor and leadership, and low in strengths like prudence, self-regulation, modesty, honesty, fairness, perseverance, and love of learning. An inspection of signature strengths revealed that 75% of class clowns had humor as a signature strength. Furthermore, class clown behaviors were generally shown by students indulging in a life of pleasure, but low life of engagement. The four dimensions yielded different character strengths profiles. While all dimensions of class clowns behaviors were low in temperance strengths, the factors "identified as the class clown" and "comic talent" were correlated with leadership strengths and the two negative factors ("disruptive rule-breaker," "subversive joker") were low in other directed strengths. The disruptive rule breaking class clown was additionally low in intellectual strengths. While humor predicted life satisfaction, class clowning tended to go along with diminished satisfaction with life. It is concluded that different types of class clowns need to be kept apart and need different attention by teachers.

  12. The Strengths Assessment Inventory: Reliability of a New Measure of Psychosocial Strengths for Youth

    Science.gov (United States)

    Brazeau, James N.; Teatero, Missy L.; Rawana, Edward P.; Brownlee, Keith; Blanchette, Loretta R.

    2012-01-01

    A new measure, the Strengths Assessment Inventory-Youth self-report (SAI-Y), was recently developed to assess the strengths of children and adolescents between the ages of 10 and 18 years. The SAI-Y differs from similar measures in that it provides a comprehensive assessment of strengths that are intrinsic to the individual as well as strengths…

  13. Is grip strength a predictor for total muscle strength in healthy children, adolescents, and young adults?

    NARCIS (Netherlands)

    Wind, Anne E.; Takken, Tim; Helders, Paul J. M.; Engelbert, Raoul H. H.

    2010-01-01

    The primary purpose of this study was to examine whether grip strength is related to total muscle strength in children, adolescents, and young adults. The second purpose was to provide reference charts for grip strength, which could be used in the clinical and research setting. This cross-sectional

  14. The relationships of character strengths with coping, work-related stress, and job satisfaction.

    Science.gov (United States)

    Harzer, Claudia; Ruch, Willibald

    2015-01-01

    Personality traits have often been highlighted to relate to how people cope with stressful events. The present paper focuses on character strengths as positive personality traits and examines two basic assumptions that were derived from a core characteristic of character strengths (i.e., to determine how individuals deal with adversities): (1) character strengths correlate with coping and (2) buffer the effects of work-related stress on job satisfaction. Two different samples (i.e., a mixed sample representing various occupations [N = 214] and a nurses sample [N = 175]) filled in measures for character strengths, coping, work-related stress, and job satisfaction. As expected, intellectual, emotional, and interpersonal strengths were related to coping. Interpersonal strengths played a greater role for coping among nurses, as interactions with others are an essential part of their workday. Furthermore, intellectual strengths partially mediated the negative effect of work-related stress on job satisfaction. These findings open a new field for research on the role of personality in coping with work-related stress. Character strengths are trainable personal characteristics, and therefore valuable resources to improve coping with work-related stress and to decrease the negative effects of stress. Further research is needed to investigate this assumed causality.

  15. The relationships of character strengths with coping, work-related stress, and job satisfaction

    Directory of Open Access Journals (Sweden)

    Claudia eHarzer

    2015-02-01

    Full Text Available Personality traits have often been highlighted to relate to how people cope with stressful events. The present paper focuses on character strengths as positive personality traits and examines two basic assumptions that were derived from a core characteristic of character strengths (i.e., to determine how individuals deal with adversities: (1 Character strengths correlate with coping and (2 buffer the effects of work-related stress on job satisfaction. Two different samples (i.e., a mixed sample representing various occupations [N = 214] and a nurses sample [N = 175] filled in measures for character strengths, coping, work-related stress, and job satisfaction. As expected, intellectual, emotional, and interpersonal strengths were related to coping. Interpersonal strengths played a greater role for coping among nurses, as interactions with others are an essential part of their workday. Furthermore, intellectual strengths partially mediated the negative effect of work-related stress on job satisfaction. These findings open a new field for research on the role of personality in coping with work-related stress. Character strengths are trainable personal characteristics, and therefore valuable resources to improve coping with work-related stress and to decrease the negative effects of stress. Further research is needed to investigate this assumed causality.

  16. Instrumental interaction

    OpenAIRE

    Luciani , Annie

    2007-01-01

    International audience; The expression instrumental interaction as been introduced by Claude Cadoz to identify a human-object interaction during which a human manipulates a physical object - an instrument - in order to perform a manual task. Classical examples of instrumental interaction are all the professional manual tasks: playing violin, cutting fabrics by hand, moulding a paste, etc.... Instrumental interaction differs from other types of interaction (called symbolic or iconic interactio...

  17. Measuring Relative Coupling Strength in Circadian Systems.

    Science.gov (United States)

    Schmal, Christoph; Herzog, Erik D; Herzel, Hanspeter

    2018-02-01

    Modern imaging techniques allow the monitoring of circadian rhythms of single cells. Coupling between these single cellular circadian oscillators can generate coherent periodic signals on the tissue level that subsequently orchestrate physiological outputs. The strength of coupling in such systems of oscillators is often unclear. In particular, effects on coupling strength by varying cell densities, by knockouts, and by inhibitor applications are debated. In this study, we suggest to quantify the relative coupling strength via analyzing period, phase, and amplitude distributions in ensembles of individual circadian oscillators. Simulations of different oscillator networks show that period and phase distributions become narrower with increasing coupling strength. Moreover, amplitudes can increase due to resonance effects. Variances of periods and phases decay monotonically with coupling strength, and can serve therefore as measures of relative coupling strength. Our theoretical predictions are confirmed by studying recently published experimental data from PERIOD2 expression in slices of the suprachiasmatic nucleus during and after the application of tetrodotoxin (TTX). On analyzing the corresponding period, phase, and amplitude distributions, we can show that treatment with TTX can be associated with a reduced coupling strength in the system of coupled oscillators. Analysis of an oscillator network derived directly from the data confirms our conclusions. We suggest that our approach is also applicable to quantify coupling in fibroblast cultures and hepatocyte networks, and for social synchronization of circadian rhythmicity in rodents, flies, and bees.

  18. Strength evaluation code STEP for brittle materials

    International Nuclear Information System (INIS)

    Ishihara, Masahiro; Futakawa, Masatoshi.

    1997-12-01

    In a structural design using brittle materials such as graphite and/or ceramics it is necessary to evaluate the strength of component under complex stress condition. The strength of ceramic materials is said to be influenced by the stress distribution. However, in the structural design criteria simplified stress limits had been adopted without taking account of the strength change with the stress distribution. It is, therefore, important to evaluate the strength of component on the basis of the fracture model for brittle material. Consequently, the strength evaluation program, STEP, on a brittle fracture of ceramic materials based on the competing risk theory had been developed. Two different brittle fracture modes, a surface layer fracture mode dominated by surface flaws and an internal fracture mode by internal flaws, are treated in the STEP code in order to evaluate the strength of brittle fracture. The STEP code uses stress calculation results including complex shape of structures analyzed by the generalized FEM stress analysis code, ABAQUS, so as to be possible to evaluate the strength of brittle fracture for the structures having complicate shapes. This code is, therefore, useful to evaluate the structural integrity of arbitrary shapes of components such as core graphite components in the HTTR, heat exchanger components made of ceramics materials etc. This paper describes the basic equations applying to the STEP code, code system with a combination of the STEP and the ABAQUS codes and the result of the verification analysis. (author)

  19. Geometry and gravity influences on strength capability

    Science.gov (United States)

    Poliner, Jeffrey; Wilmington, Robert P.; Klute, Glenn K.

    1994-01-01

    Strength, defined as the capability of an individual to produce an external force, is one of the most important determining characteristics of human performance. Knowledge of strength capabilities of a group of individuals can be applied to designing equipment and workplaces, planning procedures and tasks, and training individuals. In the manned space program, with the high risk and cost associated with spaceflight, information pertaining to human performance is important to ensuring mission success and safety. Knowledge of individual's strength capabilities in weightlessness is of interest within many areas of NASA, including workplace design, tool development, and mission planning. The weightless environment of space places the human body in a completely different context. Astronauts perform a variety of manual tasks while in orbit. Their ability to perform these tasks is partly determined by their strength capability as demanded by that particular task. Thus, an important step in task planning, development, and evaluation is to determine the ability of the humans performing it. This can be accomplished by utilizing quantitative techniques to develop a database of human strength capabilities in weightlessness. Furthermore, if strength characteristics are known, equipment and tools can be built to optimize the operators' performance. This study examined strength in performing a simple task, specifically, using a tool to apply a torque to a fixture.

  20. Strength training for children and adolescents.

    Science.gov (United States)

    Faigenbaum, A D

    2000-10-01

    The potential benefits of youth strength training extend beyond an increase in muscular strength and may include favorable changes in selected health- and fitness-related measures. If appropriate training guidelines are followed, regular participation in a youth strength-training program has the potential to increase bone mineral density, improve motor performance skills, enhance sports performance, and better prepare our young athletes for the demands of practice and competition. Despite earlier concerns regarding the safety and efficacy of youth strength training, current public health objectives now aim to increase the number of boys and girls age 6 and older who regularly participate in physical activities that enhance and maintain muscular fitness. Parents, teachers, coaches, and healthcare providers should realize that youth strength training is a specialized method of conditioning that can offer enormous benefit but at the same time can result in serious injury if established guidelines are not followed. With qualified instruction, competent supervision, and an appropriate progression of the volume and intensity of training, children and adolescents cannot only learn advanced strength training exercises but can feel good about their performances, and have fun. Additional clinical trails involving children and adolescents are needed to further explore the acute and chronic effects of strength training on a variety of anatomical, physiological, and psychological parameters.

  1. Behaviour and strength assessment of masonry prisms

    Directory of Open Access Journals (Sweden)

    Nassif Nazeer Thaickavil

    2018-06-01

    Full Text Available This is a case study presenting the cracking behavior and assessment of the compressive strength of masonry prisms. The compressive strength of masonry was determined by performing laboratory tests on 192 masonry prism specimens corresponding to 3 specimens each in 64 groups. The variables considered in the experimental program are type of brick, strength of masonry and height-to-thickness (h/t ratio of the prism specimen. Pressed earth bricks and burnt clay bricks were used for the preparation of masonry prisms. A mathematical model is also proposed for the estimation of compressive strength of masonry prisms by performing a statistical multiple regression analysis on 232 data sets, which includes 64 test data from the present study and 168 test data published in the literature. The model was developed based on the regression analysis of test data of prisms made of a variety of masonry units namely clay bricks, pressed earth bricks, concrete blocks, calcium silicate bricks, stone blocks, perforated bricks and soft mud bricks. The proposed model not only accounts for the wide ranges of compressive strengths of masonry unit and mortar, but also accounts for the influence of volume fractions of masonry unit and mortar in addition to the height-to-thickness ratio. The predicted compressive strength of prisms using the proposed model is compared with 14 models available in published literature. The predicted strength was found to be in good agreement with the corresponding experimental data. Keywords: Prism strength, Stack bonded masonry, Running bonded masonry, Masonry unit strength, Cracking

  2. Predicting hand function in older adults: evaluations of grip strength, arm curl strength, and manual dexterity.

    Science.gov (United States)

    Liu, Chiung-Ju; Marie, Deana; Fredrick, Aaron; Bertram, Jessica; Utley, Kristen; Fess, Elaine Ewing

    2017-08-01

    Hand function is critical for independence in activities of daily living for older adults. The purpose of this study was to examine how grip strength, arm curl strength, and manual dexterous coordination contributed to time-based versus self-report assessment of hand function in community-dwelling older adults. Adults aged ≥60 years without low vision or neurological disorders were recruited. Purdue Pegboard Test, Jamar hand dynamometer, 30-second arm curl test, Jebsen-Taylor Hand Function Test, and the Late-Life Function and Disability Instrument were administered to assess manual dexterous coordination, grip strength, arm curl strength, time-based hand function, and self-report of hand function, respectively. Eighty-four adults (mean age = 72 years) completed the study. Hierarchical multiple regressions show that older adults with better arm curl strength (β = -.25, p function test. In comparison, older adults with better grip strength (β = .40, p function. The relationship between grip strength and hand function may be test-specific. Grip strength becomes a significant factor when the test requires grip strength to successfully complete the test tasks. Arm curl strength independently contributed to hand function in both time-based and self-report assessments, indicating that strength of extrinsic muscles of the hand are essential for hand function.

  3. Are only Emotional Strengths Emotional? Character Strengths and Disposition to Positive Emotions.

    Science.gov (United States)

    Güsewell, Angelika; Ruch, Willibald

    2012-07-01

    This study aimed to examine the relations between character strengths and dispositional positive emotions (i.e. joy, contentment, pride, love, compassion, amusement, and awe). A sample of 574 German-speaking adults filled in the Dispositional Positive Emotion Scales (DPES; Shiota, Keltner, & John, 2006), and the Values in Action Inventory of Strengths (VIA-IS; Peterson, Park, & Seligman, 2005). The factorial structure of the DPES was examined on item level. Joy and contentment could not be clearly separated; the items of the other five emotions loaded on separate factors. A confirmatory factor analysis assuming two latent factors (self-oriented and object/situation specific) was computed on scale level. Results confirmed the existence of these factors, but also indicated that the seven emotions did not split up into two clearly separable families. Correlations between dispositional positive emotions and character strengths were positive and generally low to moderate; a few theoretically meaningful strengths-emotions pairs yielded coefficients>.40. Finally, the link between five character strengths factors (i.e. emotional strengths, interpersonal strengths, strengths of restraint, intellectual strengths, and theological strengths) and the emotional dispositions was examined. Each of the factors displayed a distinctive "emotional pattern"; emotional strengths evidenced the most numerous and strongest links to emotional dispositions. © 2012 The Authors. Applied Psychology: Health and Well-Being © 2012 The International Association of Applied Psychology.

  4. Strength properties of concrete at elevated temperatures

    International Nuclear Information System (INIS)

    Freskakis, G.N.; Burrow, R.C.; Debbas, E.B.

    1979-01-01

    A study is presented concerning the compressive strength, modulus of elasticity, and stress-strain relationships of concrete at elevated temperatures. A review of published results provides information for the development of upper and lower bound relationships for compressive strength and the modulus of elasticity and establishes exposure conditions for a lower bound thermal response. The relationships developed from the literature review are confirmed by the results of a verification test program. The strength and elasticity relationships provide a basis for the development of design stress-strain curves for concrete exposed to elevated temperatures

  5. Neutron source strength associated with FTR fuel

    International Nuclear Information System (INIS)

    Boroughs, G.L.; Bunch, W.L.; Johnson, D.L.

    1975-01-01

    The study presented shows the important effect of shelf life on the neutron source strength anticipated from fuel irradiated in the FTR. The neutron source strength will be enhanced appreciably by extended shelf lives. High neutron source strengths will also be associated with reprocessed LWR plutonium, which is expected to contain a greater abundance of the higher isotopes. The branching ratio and cross section of 241 Am is an important parameter that needs to be defined more precisely to establish calculated values with greater precision

  6. Strength of low-carbon rotor steel

    International Nuclear Information System (INIS)

    Voropaev, V.I.; Filimonov, O.V.; Borisov, I.A.

    1988-01-01

    The results of studying the effect of chemical composition and thermal treatment regimes on the structural strength of steels of the 25KhN3MFA type are presented. It is shown that alloying with niobium from 0.01 to 0.08% steels with the increased nickel content (4.2-4.5%) contributes to the increase of structural strength and reduction of semibrittleness temperature. To obtain high values of strength and plastic properties cooling with the rate of 10 3 -10 5 K/hr is recommended

  7. Adhesion Strength of Biomass Ash Deposits

    DEFF Research Database (Denmark)

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao

    2016-01-01

    . Therefore, timely removal of ash deposits is essential for optimal boiler operation. In order to improve the qualitative and quantitative understanding of deposit shedding in boilers, this study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash...... deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000 °C. Subsequently, the deposits were sheared off by an electrically controlled arm, and the corresponding adhesion strength was measured. The results reveal the effect of temperature, ash/deposit composition......, sintering duration, and steel type on the adhesion strength....

  8. Adhesion Strength of Biomass Ash Deposits

    DEFF Research Database (Denmark)

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao

    2015-01-01

    This study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000°C. Subsequently, the deposits were sheared off with the help of an electrically...... controlled arm. Higher sintering temperatures resulted in greater adhesion strengths, with a sharp increase observed near the melting point of the ash. Repetition of experiments with fixed operation conditions revealed considerable variation in the obtained adhesion strengths, portraying the stochastic...

  9. INFLUENCE OF STRENGTH TRAINING PROGRAM ON ISOMETRIC MUSCLE STRENGTH IN YOUNG ATHLETES

    Directory of Open Access Journals (Sweden)

    Dragan Radovanovic

    2007-10-01

    Full Text Available Strength training, or resistance training, is a form of physical conditioning used to increase the ability to resist force. Since muscular strength is required for success in many sports, it is logical to assume that stronger and more powerful young athletes will achieve better results. The aim of the study was to examine the effects of strength training on young athletes. An eight-week strength training program for developing muscle strength was performed in this study. Training protocol was designed specifically for young adolescent’s athletes. The program consisted of exercises for lower and upper body, abdominal and lower back muscles. The programs did not involve the maximal (1-3 repetitions maximum and other very hard intensity exercises that may had negative effect on young athletes. The results showed that strength training program had positive effects on maximal isometric muscle force (Fmax and motor skill. The increase presents the combined influence of strength training and growth.

  10. Ionic strength independence of charge distributions in solvation of biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Virtanen, J. J. [Department of Chemistry, University of Chicago, Chicago, Illinois 60637 (United States); James Franck Institute, University of Chicago, Chicago, Illinois 60637 (United States); Sosnick, T. R. [Department of Biochemistry and Molecular Biology, Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois 60637 (United States); Computation Institute, University of Chicago, Chicago, Illinois 60637 (United States); Freed, K. F. [Department of Chemistry, University of Chicago, Chicago, Illinois 60637 (United States); James Franck Institute, University of Chicago, Chicago, Illinois 60637 (United States); Computation Institute, University of Chicago, Chicago, Illinois 60637 (United States)

    2014-12-14

    Electrostatic forces enormously impact the structure, interactions, and function of biomolecules. We perform all-atom molecular dynamics simulations for 5 proteins and 5 RNAs to determine the dependence on ionic strength of the ion and water charge distributions surrounding the biomolecules, as well as the contributions of ions to the electrostatic free energy of interaction between the biomolecule and the surrounding salt solution (for a total of 40 different biomolecule/solvent combinations). Although water provides the dominant contribution to the charge density distribution and to the electrostatic potential even in 1M NaCl solutions, the contributions of water molecules and of ions to the total electrostatic interaction free energy with the solvated biomolecule are comparable. The electrostatic biomolecule/solvent interaction energies and the total charge distribution exhibit a remarkable insensitivity to salt concentrations over a huge range of salt concentrations (20 mM to 1M NaCl). The electrostatic potentials near the biomolecule's surface obtained from the MD simulations differ markedly, as expected, from the potentials predicted by continuum dielectric models, even though the total electrostatic interaction free energies are within 11% of each other.

  11. Ionic strength independence of charge distributions in solvation of biomolecules

    International Nuclear Information System (INIS)

    Virtanen, J. J.; Sosnick, T. R.; Freed, K. F.

    2014-01-01

    Electrostatic forces enormously impact the structure, interactions, and function of biomolecules. We perform all-atom molecular dynamics simulations for 5 proteins and 5 RNAs to determine the dependence on ionic strength of the ion and water charge distributions surrounding the biomolecules, as well as the contributions of ions to the electrostatic free energy of interaction between the biomolecule and the surrounding salt solution (for a total of 40 different biomolecule/solvent combinations). Although water provides the dominant contribution to the charge density distribution and to the electrostatic potential even in 1M NaCl solutions, the contributions of water molecules and of ions to the total electrostatic interaction free energy with the solvated biomolecule are comparable. The electrostatic biomolecule/solvent interaction energies and the total charge distribution exhibit a remarkable insensitivity to salt concentrations over a huge range of salt concentrations (20 mM to 1M NaCl). The electrostatic potentials near the biomolecule's surface obtained from the MD simulations differ markedly, as expected, from the potentials predicted by continuum dielectric models, even though the total electrostatic interaction free energies are within 11% of each other

  12. Oscillator strengths and radiative rates for transitions in neutral sulfur

    International Nuclear Information System (INIS)

    Deb, N.C.; Hibbert, A.

    2008-01-01

    We present accurate oscillator strengths and radiative rates for 2173 E1 transitions among the 120 levels belonging to 3s 2 3p 4 , 3s3p 5 , and 3s 2 3p 3 ( 4 S o , 2 D o , 2 P o )nl configurations where nl=4s,5s,6s,4p,5p,6p,3d,4d,4f,5f. A configuration interaction approach is employed through the standard CIV3 program. The 114 LS states included in the present calculation generate 250 fine-structure levels belonging to the above configurations below 100,000 cm -1 . However, results of only 120 fine-structure levels are presented due to the absence of experimental energy values for the remaining levels. Tabulations of oscillator strengths and radiative rates, and their comparison with other calculations, are presented in the first two tables. In a separate table the oscillator strengths and transition probabilities, in length and velocity gauges, are presented for 2173 E1 transitions, and are arranged in ascending order of wavelength

  13. Experimental Verification of the Structural Glass Beam-Columns Strength

    Science.gov (United States)

    Pešek, Ondřej; Melcher, Jindřich; Balázs, Ivan

    2017-10-01

    This paper deals with experimental research of axially and laterally loaded members made of structural (laminated) glass. The purpose of the research is the evaluation of buckling strength and actual behaviour of the beam-columns due to absence of standards for design of glass load-bearing structures. The experimental research follows the previous one focusing on measuring of initial geometrical imperfections of glass members, testing of glass beams and columns. Within the frame of the research 9 specimens were tested. All of them were of the same geometry (length 2000 mm, width 200 mm and thickness 16 mm) but different composition - laminated double glass made of annealed glass or fully tempered glass panes bonded together by PVB or EVASAFE foil. Specimens were at first loaded by axial force and then by constantly increasing bending moment up to failure. During testing lateral deflections, vertical deflection and normal stresses at mid-span were measured. A maximum load achieved during testing has been adopted as flexural-lateral-torsional buckling strength. The results of experiments were statistically evaluated according to the European standard for design of structures EN 1990, appendix D. There are significant differences between specimens made of annealed glass or fully tempered glass. Differences between specimens loaded by axial forces 1 kN and 2 kN are negligible. The next step was to determine the design strength by calculation procedure based on buckling curves approach intended for design of steel columns and develop interaction criterion for glass beams-columns.

  14. Comparative study of maximum isometric grip strength in different sports

    Directory of Open Access Journals (Sweden)

    Noé Gomes Borges Junior

    2009-06-01

    Full Text Available The objective of this study was to compare maximum isometric grip strength (Fmaxbetween different sports and between the dominant (FmaxD and non-dominant (FmaxND hand. Twenty-nine male aikido (AI, jiujitsu (JJ, judo (JU and rowing (RO athletes and 21non-athletes (NA participated in the study. The hand strength test consisted of maintainingmaximum isometric grip strength for 10 seconds using a hand dynamometer. The position of the subjects was that suggested by the American Society of Hand Therapy. Factorial 2X5 ANOVA with Bonferroni correction, followed by a paired t test and Tukey test, was used for statistical analysis. The highest Fmax values were observed for the JJ group when using the dominant hand,followed by the JU, RO, AI and NA groups. Variation in Fmax could be attributed to handdominance (30.9%, sports modality (39.9% and the interaction between hand dominance andsport (21.3%. The present results demonstrated significant differences in Fmax between the JJ and AI groups and between the JJ and NA groups for both the dominant and non-dominant hand. Significant differences in Fmax between the dominant and non-dominant hand were only observed in the AI and NA groups. The results indicate that Fmax can be used for comparisonbetween different sports modalities, and to identify differences between the dominant and nondominanthand. Studies involving a larger number of subjects will permit the identification of differences between other modalities.

  15. Strength Tests on Hulls and Floats

    Science.gov (United States)

    Matthaes, K

    1942-01-01

    The present report deals with strength tests on hulls and floats intended in part for the collection of construction data for the design of these components and in part for the stress analysis of the finished hulls and floats.

  16. Magnetic Field Strength Evaluation Yu. S. Yefimov

    Indian Academy of Sciences (India)

    physical task is to evaluate the strength and topology of magnetic field in blazars and related ... polarization, spectral index of radiation, ratio of apparent velocity of the motion of matter along .... A detailed analysis of the evaluation of physical.

  17. Shear strength of clay and silt embankments.

    Science.gov (United States)

    2009-09-01

    Highway embankment is one of the most common large-scale geotechnical facilities constructed in Ohio. In the past, the design of these embankments was largely based on soil shear strength properties that had been estimated from previously published e...

  18. Pilates: Build Strength in Your Core Muscles

    Science.gov (United States)

    Healthy Lifestyle Fitness Pilates may sound intimidating, but it's an accessible way to build strength in your core muscles for better posture, balance and flexibility. By Mayo Clinic Staff Pilates isn't just for fitness fanatics. It's actually ...

  19. Personality Typology in Relation to Muscle Strength

    Science.gov (United States)

    Terracciano, Antonio; Milaneschi, Yuri; Metter, E. Jeffrey; Ferrucci, Luigi

    2011-01-01

    Background Physical inactivity plays a central role in the age-related decline in muscle strength, an important component in the process leading to disability. Personality, a significant determinant of health behaviors including physical activity, could therefore impact muscle strength throughout adulthood and affect the rate of muscle strength decline with aging. Personality typologies combining “high neuroticism” (N≥55), “low extraversion” (Epersonality types. Facet analyses suggest an important role for the N components of depression and hostility. Physical activity level appears to partly explain some of these associations. Conclusion Findings provide support for the notion that the typological approach to personality may be useful in identifying specific personality types at risk of low muscle strength and offer the possibility for more targeted prevention and intervention programs. PMID:21614452

  20. Neural adaptations to electrical stimulation strength training

    NARCIS (Netherlands)

    Hortobagyi, Tibor; Maffiuletti, Nicola A.

    2011-01-01

    This review provides evidence for the hypothesis that electrostimulation strength training (EST) increases the force of a maximal voluntary contraction (MVC) through neural adaptations in healthy skeletal muscle. Although electrical stimulation and voluntary effort activate muscle differently, there

  1. Statistical Analysis of Data for Timber Strengths

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Hoffmeyer, P.

    Statistical analyses are performed for material strength parameters from approximately 6700 specimens of structural timber. Non-parametric statistical analyses and fits to the following distributions types have been investigated: Normal, Lognormal, 2 parameter Weibull and 3-parameter Weibull...

  2. Collision strengths for transitions in Ni XIX

    Indian Academy of Sciences (India)

    4l configurations of Ni XIX, for which flexible atomic code. (FAC) has been ... atomic data (namely energy levels, radiative rates, collision strengths, excitation rates, etc.) ... Zhang and Sampson, who adopted the Coulomb–Born-exchange.

  3. Influence of processing factors over concrete strength.

    Science.gov (United States)

    Kara, K. A.; Dolzhenko, A. V.; Zharikov, I. S.

    2018-03-01

    Construction of facilities of cast in-situ reinforced concrete poses additional requirements to quality of material, peculiarities of the construction process may sometimes lead to appearance of lamination planes and inhomogeneity of concrete, which reduce strength of the material and structure as a whole. Technology compliance while working with cast in-situ concrete has a significant impact onto the concrete strength. Such process factors as concrete curing, vibration and compaction of the concrete mixture, temperature treatment, etc., when they are countered or inadequately followed lead to a significant reduction in concrete strength. Here, the authors experimentally quantitatively determine the loss of strength in in-situ cast concrete structures due to inadequate following of process requirements, in comparison with full compliance.

  4. Nutritional Supplements for Strength Power Athletes

    Science.gov (United States)

    Wilborn, Colin

    Over the last decade research involving nutritional supplementation and sport performance has increased substantially. Strength and power athletes have specific needs to optimize their performance. Nutritional supplementation cannot be viewed as a replacement for a balanced diet but as an important addition to it. However, diet and supplementation are not mutually exclusive, nor does one depend on the other. Strength and power athletes have four general areas of supplementation needs. First, strength athletes need supplements that have a direct effect on performance. The second group of supplements includes those that promote recovery. The third group comprises the supplements that enhance immune function. The last group of supplements includes those that provide energy or have a direct effect on the workout. This chapter reviews the key supplements needed to optimize the performance and training of the strength athlete.

  5. Strength and power of knee extensor muscles

    Directory of Open Access Journals (Sweden)

    Knežević Olivera

    2011-01-01

    Full Text Available In the studies of human neuromuscular function, the function of leg muscles has been most often measured, particularly the function of the knee extensors. Therefore, this review will be focused on knee extensors, methods for assessment of its function, the interdependence of strength and power, relations that describe these two abilities and the influence of various factors on their production (resistance training, stretching, movement tasks, age, etc.. Given that it consists of four separate muscles, the variability of their anatomical characteristics affects their participation in strength and power production, depending on the type of movement and motion that is performed. Since KE is active in a variety of activities it must be able to generate great strength in a large and diverse range of muscle lengths and high shortening velocities, in respect to different patterns of strength production, and thus different generation capacities within the muscle (Blazevich et al., 2006. It has been speculated that KE exerts its Pmax at workloads close to subject's own body weight or lower (Rahmani et al., 2001, which is very close to the maximum dynamic output hypothesis (MDI of Jaric and Markovic (2009. Changes under the influence of resistance training or biological age are variously manifested in muscle's morphological, physiological and neural characteristics, and thus in strength and power. Understanding the issues related to strength and power as abilities of great importance for daily activities, is also important for sports and rehabilitation. Performances improvement in sports in which leg muscles strength and power are crucial, as well as recovery after the injuries, are largely dependent on the research results regarding KE function. Also, the appropriate strength balance between knee flexors and extensors is important for the knee joint stability, so that the presence of imbalance between these two muscle groups might be a risk factor for

  6. Strength and structure of nanocrystalline titanium

    International Nuclear Information System (INIS)

    Noskova, N.I.; Pereturina, I.A.; Elkina, O.A.; Stolyarov, V.V.

    2004-01-01

    Investigation results on strength and plasticity of nanocrystalline titanium VT-1 are presented. Specific features of plastic deformation on tension of this material specimens in an electron microscope column are studied in situ. It is shown that nanocrystalline titanium strength and plasticity at room temperature are dependent on the structure and nanograin size. It is revealed that deformation processes in nanocrystalline titanium are characterized by activation of deformation rotational modes and microtwinning [ru

  7. Equilibrium and non-equilibrium cluster phases in colloids with competing interactions

    NARCIS (Netherlands)

    Mani, Ethayaraja; Lechner, Wolfgang; Kegel, Willem K.; Bolhuis, Peter G.

    2014-01-01

    The phase behavior of colloids that interact via competing interactions-short-range attraction and long-range repulsion-is studied by computer simulation. In particular, for a fixed strength and range of repulsion, the effect of the strength of an attractive interaction (ε) on the phase behavior is

  8. Weak interactions

    International Nuclear Information System (INIS)

    Chanda, R.

    1981-01-01

    The theoretical and experimental evidences to form a basis for Lagrangian Quantum field theory for Weak Interactions are discussed. In this context, gauge invariance aspects of such interactions are showed. (L.C.) [pt

  9. Percentage Level of Tannin fur Rabbit for Leather Concerning Stitch Tearing Strength, Tearing Strength and Flexibility

    Directory of Open Access Journals (Sweden)

    Mustakim Mustakim

    2012-02-01

    Full Text Available The purpose of this study was to find out the appropriate of tannin level for rabbit fur leather concerning stitch tearing strength, tearing strength, and flexibility. The result were expected to contribute good information for the society, leather craftsman, and further researchers about fur leather tanning especially rabbit fur leather with tannin concerning stitch tearing strength, tearing strength and flexibility. The material that used were 12 pieces of four months of rabbit skin. The research method was Completely Randomized Design, consist of three treatments of tannin, they were: M1 (mimosa 15%, M2 (mimosa 20%, and M3 (mimosa 25%. Each of treatment hold on four repetition, the variables which measured were stitch tearing strength, tearing strength, and flexibility of fur leather. Data were  analysed by analysis variance followed by Duncan’s Multiple Range Test. The result of this research indicate that the use level of tannin give significant influence (P<0.05 among stitch tearing strength, tearing strength. It gave a very significant influence (P<0.01 for flexibility of rabbit fur leather. Based on the result, can be concluded that 25 % of tannin (mimosa, produce the best  result on stitch tearing strength and tearing strength. The increase of tannin offer will decrease the flexibility of fur leather but the lowest tannin produced the best flexibility of fur leather (15 percent. The best quality of rabbit fur leather produced by 25 % of tannin.   Keywords : leather, tannin, quality

  10. Upper extremity injuries associated with strength training.

    Science.gov (United States)

    Haupt, H A

    2001-07-01

    Most injuries sustained during strength training are mild strains that resolve with appropriate rest. More severe injuries include traumatic shoulder dislocations, tendon ruptures of the pectoralis major, biceps, and triceps; stress fractures of the distal clavicle, humerus, radius, and ulna; traumatic fractures of the distal radius and ulna in adolescent weightlifters; and compressive and stretch neuropathies. These more severe injuries are usually the result of improperly performing a strength training exercise. Educating athletes regarding proper strength-training techniques serves to reverse established injury patterns and to prevent these injuries in the first place. Recognizing the association of anabolic steroid use to several of the injury patterns further reinforces the need for medical specialists to counsel athletes against their use. With the increasing use of supplements such as creatine, the incidence and nature of strength-training injuries may change further. Greater emphasis on the competitive performance of younger athletes undoubtedly will generate enthusiasm for strength training at earlier ages in both sexes. The importance of proper supervision of these young athletes by knowledgeable persons will increase. As the popularity of strength training grows, there will be ample opportunity to continue to catalog the injury patterns associated with this activity.

  11. Strength Testing in Motor Neuron Diseases.

    Science.gov (United States)

    Shefner, Jeremy M

    2017-01-01

    Loss of muscle strength is a cardinal feature of all motor neuron diseases. Functional loss over time, including respiratory dysfunction, inability to ambulate, loss of ability to perform activities of daily living, and others are due, in large part, to decline in strength. Thus, the accurate measurement of limb muscle strength is essential in therapeutic trials to best understand the impact of therapy on vital function. While qualitative strength measurements show declines over time, the lack of reproducibility and linearity of measurement make qualitative techniques inadequate. A variety of quantitative measures have been developed; all have both positive attributes and limitations. However, with careful training and reliability testing, quantitative measures have proven to be reliable and sensitive indicators of both disease progression and the impact of experimental therapy. Quantitative strength measurements have demonstrated potentially important therapeutic effects in both amyotrophic lateral sclerosis and spinobulbar muscular atrophy, and have been shown feasible in children with spinal muscular atrophy. The spectrum of both qualitative and quantitative strength measurements are reviewed and their utility examined in this review.

  12. Strength functions for fragmented doorway states

    International Nuclear Information System (INIS)

    MacDonald, W.M.

    1980-01-01

    Coupling a strongly excited ''doorway state'' to weak ''hallway states'' distributes its strength into micro-resonances seen in differential cross sections taken with very good energy resolution. The distribution of strength is shown to be revealed by reduced widths of the K-matrix rather than by the imaginary part of poles of the S-matrix. Different strength functions (SF) constructed by averaging the K-matrix widths are then investigated to determine their dependences on energy and on parameters related to averages of microscopic matrix elements. A new sum rule on the integrated strength of these SF is derived and used to show that different averaging procedures actually distribute the strength differently. Finally, it is shown that the discontinuous summed strength defines spreading parameters for the doorway state only in strong coupling, where it approximates the idefinite integral of the continuous SF of MacDonald-Mekjian-Kerman-De Toledo Piza. A new method of ''parametric continuation'' is used to relate a discontinuous sliding box-average, or a finite sum, of discrete terms to a continous function

  13. Strength gradient enhances fatigue resistance of steels

    Science.gov (United States)

    Ma, Zhiwei; Liu, Jiabin; Wang, Gang; Wang, Hongtao; Wei, Yujie; Gao, Huajian

    2016-02-01

    Steels are heavily used in infrastructure and the transportation industry, and enhancing their fatigue resistance is a major challenge in materials engineering. In this study, by introducing a gradient microstructure into 304 austenitic steel, which is one of the most widely used types of stainless steel, we show that a strength gradient substantially enhances the fatigue life of the material. Pre-notched samples with negative strength gradients in front of the notch’s tip endure many more fatigue cycles than do samples with positive strength gradients during the crack initiation stage, and samples with either type of gradient perform better than do gradient-free samples with the same average yield strength. However, as a crack grows, samples with positive strength gradients exhibit better resistance to fatigue crack propagation than do samples with negative gradients or no gradient. This study demonstrates a simple and promising strategy for using gradient structures to enhance the fatigue resistance of materials and complements related studies of strength and ductility.

  14. On high temperature strength of carbon steels

    International Nuclear Information System (INIS)

    Ichinose, Hiroyuki; Tamura, Manabu; Kanero, Takahiro; Ihara, Yoshihito

    1977-01-01

    In the steels for high temperature use, the oxidation resistance is regarded as important, but carbon steels show enough oxidation resistance to be used continuously at the temperature up to 500 deg. C if the strength is left out of consideration, and up to 450 deg. C even when the strength is taken into account. Moreover, the production is easy, the workability and weldability are good, and the price is cheap in carbon steels as compared with alloy steels. In the boilers for large thermal power stations, 0.15-0.30% C steels are used for reheater tubes, main feed water tubes, steam headers, wall water tubes, economizer tubes, bypass pipings and others, and they account for 70% of all steel materials used for the boilers of 350 MW class and 30% in 1000 MW class. The JIS standard for the carbon steels for high temperature use and the related standards in foreign countries are shown. The high temperature strength of carbon steels changes according to the trace elements, melting and heat treatment as well as the main compositions of C, Si and Mn. Al and N affect the high temperature strength largely. The characteristics of carbon steels after the heating for hours, the factors controlling the microstructure and high temperature strength, and the measures to improve the high temperature strength of carbon steels are explained. (Kako, I.)

  15. Mapping strengths into virtues: The relation of the 24 VIA-strengths to six ubiquitous virtues

    Directory of Open Access Journals (Sweden)

    Willibald eRuch

    2015-04-01

    Full Text Available The Values-in-Action (VIA-classification distinguishes six core virtues and 24 strengths. As the assignment of the strengths to the virtues was done on theoretical grounds it still needs empirical verification. As an alternative to factor analytic investigations the present study utilizes expert judgments. In a pilot study the conceptual overlap among five sources of knowledge (strength’s name including synonyms, short definitions, brief descriptions, longer theoretical elaborations, and item content about a particular strength was examined. The results show that the five sources converged quite well, with the short definitions and the items being slightly different from the other. All strengths exceeded a cut-off value but the convergence was much better for some strengths (e.g., zest than for others (e.g., perspective. In the main study 70 experts (from psychology, philosophy, theology, etc. and 41 laypersons rated how prototypical the strengths are for each of the six virtues. The results showed that 10 were very good markers for their virtues, 9 were good markers, four were acceptable markers, and only one strength failed to reach the cut-off score for its assigned virtue. However, strengths were often markers for two or even three virtues, and occasionally they marked the other virtue more strongly than the one they were assigned to. The virtue prototypicality ratings were slightly positively correlated with higher coefficients being found for justice and humanity. A factor analysis of the 24 strengths across the ratings yielded the six factors with an only slightly different composition of strengths and double loadings. It is proposed to adjust either the classification (by reassigning strengths and by allowing strengths to be subsumed under more than one virtue or to change the definition of certain strengths so that they only exemplify one virtue. The results are discussed in the context of factor analytic attempts to verify the

  16. Increasing Lean Mass and Strength: A Comparison of High Frequency Strength Training to Lower Frequency Strength Training.

    Science.gov (United States)

    Thomas, Michael H; Burns, Steve P

    The purpose of this study was to determine the effect strength training frequency has on improvements in lean mass and strength. Participants were 7 women and 12 men, age ( χ̄ = 34.64 years ± 6.91 years), with strength training experience, training age ( χ̄ = 51.16 months ± 39.02 months). Participants were assigned to one of two groups to equal baseline group demographics. High frequency training group (HFT) trained each muscle group as the agonist, 3 times per week, exercising with 3 sets per muscle group per session (3 total body workouts). Low frequency training group (LFT) trained each muscle group as the agonist one time per week, completing all 9 sets during that one workout. LFT consisted of a routine split over three days: 1) pectoralis, deltoids, and triceps; 2) upper back and biceps; 3) quadriceps, hamstrings, calves, and abdominals. Following eight weeks of training, HFT increased lean mass by 1.06 kg ± 1.78 kg, (1.9%), and LFT increased lean mass by .99 kg ± 1.31 kg, (2.0%). HFT strength improvements on the chest press was 9.07 kg ± 6.33 kg, (11%), and hack squat 20.16 kg ± 11.59 kg, (21%). LFT strength improvements on chest press was 5.80kg ± 4.26 kg, (7.0%), and hack squat 21.83 kg ± 11.17 kg, (24 %). No mean differences between groups were significant. These results suggest that HFT and LFT of equal set totals result in similar improvements in lean mass and strength, following 8 weeks of strength training.

  17. Intermolecular interactions

    International Nuclear Information System (INIS)

    Kaplan, I.G.; Rodimova, O.B.; AN SSSR, Tomsk. Inst. Optiki Atmosfery)

    1978-01-01

    The present state of the intermolecular interaction theory is described. The general physical picture of the molecular interactions is given, the relative contributions of interactions of different types are analyzed (electrostatic, resonance, induction, dispersion, relativistic, magnetostatic and exchange), and the main ones in each range of separations are picked out. The methods of the potential curve calculations are considered, specific for definite separations between the interacting systems. The special attention is paid to the analysis of approximations used in different theoretical calculation methods

  18. Collision strengths for the excitation of lithium- and boron-like ions by electron impact

    International Nuclear Information System (INIS)

    Goett, S.J.

    1983-01-01

    The theory of collision strengths of highly charged ions is presented in terms of the R-matrix formalism by utilizing time-dependent perturbation theory. This theory is then applied to the general case of an ion with three valence electrons. The theory is general enough to admit the possiblity of three equivalent electrons. The effects of configuration interaction and intermediate coupling are incorporated through the mixing coefficients calculated by diagonalizing the perturbation matrix. This matrix is formed by taking into account the electron-electron electrostatic interaction as well as all first order relativistic corrections. The dipole radiative line strengths are also calculated using these mix coefficients. The line strengths are needed for the Coulomb-Bethe approximation which estimates the contributions to the collision strengths from large values of the impact electron's orbital angular momentum. All the above quantities are calculated in both the LS and jj coupling schemes. This dual calculation provides useful information about the mixing of the states present, as well as serving as a valuable check on the development of the theory and the coding of the computer programs. An application is made to the calculation of transition energies, line strengths and collision strengths of transitions from all lower states with a configuration of 1s 2 2I to all upper states with a configuraiton of 1s2I/sub a/'2I/sub b/'

  19. Physical activity, but not sedentary time, influences bone strength in late adolescence.

    Science.gov (United States)

    Tan, Vina Ps; Macdonald, Heather M; Gabel, Leigh; McKay, Heather A

    2018-03-20

    Physical activity is essential for optimal bone strength accrual, but we know little about interactions between physical activity, sedentary time, and bone outcomes in older adolescents. Physical activity (by accelerometer and self-report) positively predicted bone strength and the distal and midshaft tibia in 15-year-old boys and girls. Lean body mass mediated the relationship between physical activity and bone strength in adolescents. To examine the influence of physical activity (PA) and sedentary time on bone strength, structure, and density in older adolescents. We used peripheral quantitative computed tomography to estimate bone strength at the distal tibia (8% site; bone strength index, BSI) and tibial midshaft (50% site; polar strength strain index, SSI p ) in adolescent boys (n = 86; 15.3 ± 0.4 years) and girls (n = 106; 15.3 ± 0.4 years). Using accelerometers (GT1M, Actigraph), we measured moderate-to-vigorous PA (MVPA Accel ), vigorous PA (VPA Accel ), and sedentary time in addition to self-reported MVPA (MVPA PAQ-A ) and impact PA (ImpactPA PAQ-A ). We examined relations between PA and sedentary time and bone outcomes, adjusting for ethnicity, maturity, tibial length, and total body lean mass. At the distal tibia, MVPA Accel and VPA Accel positively predicted BSI (explained 6-7% of the variance, p accounting for lean mass. Sedentary time did not independently predict bone strength at either site. Greater tibial bone strength in active adolescents is mediated, in part, by lean mass. Despite spending most of their day in sedentary pursuits, adolescents' bone strength was not negatively influenced by sedentary time.

  20. Hip adduction and abduction strength profiles in elite soccer players

    DEFF Research Database (Denmark)

    Thorborg, Kristian; Serner, Andreas; Petersen, Jesper

    2011-01-01

    An ipsilateral hip adduction/abduction strength ratio of more than 90%, and hip adduction strength equal to that of the contralateral side have been suggested to clinically represent adequate strength recovery of hip adduction strength in athletes after groin injury. However, to what extent side-......-to-side symmetry in isometric hip adduction and abduction strength can be assumed in soccer players remains uncertain.......An ipsilateral hip adduction/abduction strength ratio of more than 90%, and hip adduction strength equal to that of the contralateral side have been suggested to clinically represent adequate strength recovery of hip adduction strength in athletes after groin injury. However, to what extent side...

  1. Evaluation of size dependent design shear strength of reinforced ...

    Indian Academy of Sciences (India)

    to the development of the size dependent models on the shear strength in ... predict the diagonal cracking strength and the ultimate shear strength of RC ... ing strength of normal beams was by Zsutty (1968) based on the data base available without .... The comparison of the calculated shear strength of the beams is shown.

  2. Temperature and pinning strength dependence of the critical current of a superconductor with a square periodic array of pinning sites

    International Nuclear Information System (INIS)

    Benkraouda, M.; Obaidat, I.M.; Al Khawaja, U.

    2006-01-01

    We have conducted extensive series of molecular dynamic simulations on driven vortex lattices interacting with periodic square arrays of pinning sites. In solving the over damped equation of vortex motion we took into account the vortex-vortex repulsion interaction, the attractive vortex-pinning interaction, and the driving Lorentz force at several values of temperature. We have studied the effect of varying the driving Lorentz force and varying the pinning strength on the critical current for several pinning densities, and temperature values. We have found that the pinning strength play an important role in enhancing the critical current over the whole temperature range. At low temperatures, the critical current was found to increase linearly with increasing the pinning strengths for all pinning densities. As the temperature increases, the effect of small pinning strengths diminishes and becomes insignificant at high temperatures

  3. The sink strengths of voids and the expected swelling for both random and ordered void distributions

    International Nuclear Information System (INIS)

    Quigley, T.M.; Murphy, S.M.; Bullough, R.; Wood, M.H.

    1981-10-01

    The sink strength of a void has been obtained when the void is a member of a random or ordered distribution of voids. The former sink strength derivation has employed the embedding model and the latter the cellular model. In each case the spatially varying size-effect interaction between the intrinsic point defects and the voids has been included together with the presence of other sink types in addition to the voids. The results are compared with previously published sink strengths that have made use of an approximate representation for the size-effect interactions, and indicate the importance of using the exact form of the interaction. In particular the bias for interstitials compared with vacancies of small voids is now much reduced and contamination of the surfaces of such voids no longer appears essential to facilitate the nucleation and growth of the voids. These new sink strengths have been used, in conjunction with recently published dislocation sink strengths, to calculate the expected swelling of materials containing network dislocations and voids. Results are presented for both the random and the void lattice situations. (author)

  4. Should Psychosocial Safety Climate Theory Be Extended to Include Climate Strength?

    Science.gov (United States)

    Afsharian, Ali; Zadow, Amy; Dollard, Maureen F; Dormann, Christian; Ziaian, Tahereh

    2017-08-31

    Psychosocial safety climate (PSC; climate for psychological health) is an organizational antecedent to work conditions articulated in the job demands-resources model. We responded to calls for broader consideration of organizational climate in terms of both climate level and strength. We tested PSC level and strength as main and interactive predictors of work conditions, psychological health, and engagement. Using multilevel analysis and cross-sectional data, the effects of unit-level PSC constructs were investigated in 21 hospital work units (n = 249 employees) in Australia. The correlation between PSC levels (measured at the unit mean) and PSC strength (measured as unit -1 × SD) was moderate and positive, suggesting that ceiling effects of PSC scores were not problematic. PSC level was a better predictor than PSC strength or their interactions for job demands (psychological and emotional demands), job resources (e.g., skill discretion and organizational support), and health (emotional exhaustion). For engagement, the interaction was significant-improving engagement, therefore, benefits from high levels of PSC and PSC strength within the work units. So, in answer to the research question regarding PSC theory extension, "it depends on the outcome." Research limitations are acknowledged, and the potential of the PSC model to guide the reduction of workplace psychosocial risk factors and the negative consequences is discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  5. Effective interactions

    International Nuclear Information System (INIS)

    Elliott, J.P.

    1981-01-01

    This chapter attempts to describe and compare some of the more important nucleon-nucleon interactions that have been used in nuclear structure calculations, and to relate them where possible to the real nucleon-nucleon interaction. Explains that different interactions have been used depending on whether one is fitting to total binding energies and densities with a Hartree Fock (HF) calculation or fitting to spectra and spectroscopic data in a shell model calculation. Examines both types of calculation after two preliminary sections concerned with notation and with the philosophy underlying the use of model spaces and effective interactions. Discusses Skyrme interactions, finite range interactions, small model space, large model space, and the Sussex potential matrix elements. Focuses on the more empirical approaches in which a simple form is chosen for the effective interaction in a given model space and the parameters are deduced from fitting many-body data

  6. The Effects of Isokinetic Strength Training on Strength at Different Angular Velocities: a Pilot Study

    Directory of Open Access Journals (Sweden)

    Tuğba Kocahan

    2017-09-01

    Conclusion: It was shown that angular velocity is important in isokinetic training, and that training at high angular velocities provides strength increases at lower angular velocities, but would not increase strength at angular velocities above the training level. For this reason, it is thought that in the preparation of an isokinetic strength training protocol, angular velocities need to be taken into account. For any athlete, the force at the angular velocity required in her/his sports branch needs to be considered.

  7. Comparison and Analysis of Steel Frame Based on High Strength Column and Normal Strength Column

    Science.gov (United States)

    Liu, Taiyu; An, Yuwei

    2018-01-01

    The anti-seismic performance of high strength steel has restricted its industrialization in civil buildings. In order to study the influence of high strength steel column on frame structure, three models are designed through MIDAS/GEN finite element software. By comparing the seismic performance and economic performance of the three models, the three different structures are comprehensively evaluated to provide some references for the development of high strength steel in steel structure.

  8. Characterization of elastic interactions in GaAs/Si composites by optically pumped nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Ryan M.; Tokarski, John T.; McCarthy, Lauren A.; Bowers, Clifford R., E-mail: bowers@chem.ufl.edu [Department of Chemistry, University of Florida, Gainesville, Florida 32611 (United States); Stanton, Christopher J. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States)

    2016-08-28

    Elastic interactions in GaAs/Si bilayer composite structures were studied by optically pumped nuclear magnetic resonance (OPNMR). The composites were fabricated by epoxy bonding of a single crystal of GaAs to a single crystal of Si at 373 K followed by selective chemical etching of the GaAs at room temperature to obtain a series of samples with GaAs thickness varying from 37 μm to 635 μm, while the Si support thickness remained fixed at 650 μm. Upon cooling to below 10 K, a biaxial tensile stress developed in the GaAs film due to differential thermal contraction. The strain perpendicular to the plane of the bilayer and localized near the surface of the GaAs was deduced from the quadrupolar splitting of the Gallium-71 OPNMR resonance. Strain relaxation by bowing of the composite was observed to an extent that depended on the relative thickness of the GaAs and Si layers. The variation of the strain with GaAs layer thickness was found to be in good agreement with a general analytical model for the elastic relationships in composite media.

  9. Integrating the strengths of cognitive emotion models with traditional HCI analysis tools

    OpenAIRE

    Springett, Mark; Law, Effie Lai-Chong; Coulson, Mark

    2015-01-01

    This paper reports an attempt to integrate key concepts from cognitive models of emotion to cognitive models of interaction established in HCI literature. The aim is to transfer the strengths of interaction models to analysis of affect-critical systems in games, e-commerce and education, thereby increasing their usefulness in these systems where affect is increasingly recognised as a key success factor. Concepts from Scherer’s appraisal model and stimulation evaluation checks, along with a fr...

  10. Influence of silica fume on the strength of high strength concrete

    International Nuclear Information System (INIS)

    Akram, T.; Memon, S.A.; Khan, S.A.

    2007-01-01

    HSC (High Strength Concrete) does not become evident by a sudden change in the behavior of 'ordinary strength' concrete. There is a gradual effect that becomes more noticeable when the strength level exceeds about 40-45 MPa. There cannot be a precise level of strength which defines this change in effect. The effects are on strength and workability, requiring us to take into account in our mix proportioning, the ramifications of fineness of cement on workability and of type of aggregate and aggregate/cement ratio on strength. In fact, the selection of materials becomes more critical as the concrete strength increases and that if very high strength is required (100 MPa and higher), relatively few materials may be suitable. An experimental investigation is carried out to evaluate the feasibility of producing HSC using locally available materials and to study the influence of silica fume on the strength of HSC. The main variables in this research is amount of silica fume. The parameters that are kept constant are the amount of cement equal to 580 kg/m3, dosage of HRWRA (High Range Water Reducing Admictures) equal to 4 % by weight of cementitious materials and the ratio of fine aggregate to coarse aggregate (1:2.3). Test results revealed that it is feasible to produce HSC using locally available materials. The optimum percentage of silica fume was found to be 15 % by weight of cement. (author)

  11. Associations of knee extensor strength and standing balance with physical function in knee osteoarthritis.

    Science.gov (United States)

    Pua, Yong-Hao; Liang, Zhiqi; Ong, Peck-Hoon; Bryant, Adam L; Lo, Ngai-Nung; Clark, Ross A

    2011-12-01

    Knee extensor strength is an important correlate of physical function in patients with knee osteoarthritis; however, it remains unclear whether standing balance is also a correlate. The purpose of this study was to evaluate the cross-sectional associations of knee extensor strength, standing balance, and their interaction with physical function. One hundred four older adults with end-stage knee osteoarthritis awaiting a total knee replacement (mean ± SD age 67 ± 8 years) participated. Isometric knee extensor strength was measured using an isokinetic dynamometer. Standing balance performance was measured by the center of pressure displacement during quiet standing on a balance board. Physical function was measured by the self-report Short Form 36 (SF-36) questionnaire and by the 10-meter fast-pace gait speed test. After adjustment for demographic and knee pain variables, we detected significant knee strength by standing balance interaction terms for both SF-36 physical function and fast-pace gait speed. Interrogation of the interaction revealed that standing balance in the anteroposterior plane was positively related to physical function among patients with lower knee extensor strength. Conversely, among patients with higher knee extensor strength, the standing balance-physical function associations were, or tended to be, negative. These findings suggest that although standing balance was related to physical function in patients with knee osteoarthritis, this relationship was complex and dependent on knee extensor strength level. These results are of importance in developing intervention strategies and refining theoretical models, but they call for further study. Copyright © 2011 by the American College of Rheumatology.

  12. Evaluation of in-place concrete strength by core testing.

    Science.gov (United States)

    2016-11-01

    The overall objective of the work contained in this report is to develop an ALDOT procedure to evaluate core strength results obtained under various conditions. Since there are many factors that influence the apparent strength of cores, strength corr...

  13. Short Communications Strength Properties and Groups of Major ...

    African Journals Online (AJOL)

    Short Communications Strength Properties and Groups of Major Commercial Timbers Grown in Kenya. ... The strength groups developed revealed that most species in Kenya are suitable for heavy engineering works and building construction. ... strength properties, commercial timber, physical and mechanical properties

  14. Fatigue strength of socket welded pipe joint

    International Nuclear Information System (INIS)

    Iida, K.; Matsuda, F.; Sato, M.; Higuchi, M.; Nakagawa, A.

    1994-01-01

    Fully reversed four point bending fatigue tests were carried out of small diameter socket welded joints made of carbon steels. Experimental parameters are pipe diameter, thickness of pipe and socket wall, throat depth and shape of fillet welds, slip-on and diametral gaps in the socket welding, lack of penetration at the root of fillet welds, and peening of fillet welds. In most cases a fatigue crack started from the root of the fillet, but in the case of higher stress amplitude, it tended to start from the toe of fillet. The standard socket welded joint of 50 mm diameter showed relatively low fatigue strength, 46 MPa in stress amplitude at the 10 7 cycles failure life. This value corresponds to about 1/5 of that of the smoothed base metal specimens in axial fatigue. The fatigue strength showed decrease with increasing pipe diameter, and increase with increasing the thickness of pipe and socket wall. The effects of throat depth and shape of fillet welds on fatigue strength were not significant. Contrary to the expectation, the fatigue strength of the socket welded joint without slip-on gap is higher than that of the joint with the normal gap. A lack of penetration at the root deleteriously reduced fatigue strength, showing 14 MPa in stress amplitude at the 10 7 cycles failure life for the 50 mm diameter socket joint. (orig.)

  15. Microtensile bond strength of enamel after bleaching.

    Science.gov (United States)

    Lago, Andrea Dias Neves; Garone-Netto, Narciso

    2013-01-01

    To evaluate the bond strength of a composite resin to the bovine enamel bleached with 35% hydrogen peroxide. It was used an etching-and-rinse adhesive system employed immediately, 7 and 14 days after the bleaching. Twenty bovine teeth were randomly distributed into 4 groups (n = 5), 3 experimental and 1 control. G1: Unbleached + restoration 14 days after storage in artificial saliva (control); G2: Bleached + restoration immediately after bleaching; G3: Bleached + restoration 7 days after bleaching; G4: Bleached + restoration 14 days after bleaching. Their buccal enamel surfaces were flattened, and a 25 mm² (5 × 5 mm) area from each one of these regions was outlined so as to standardize the experimental region. Universal hybrid composite resin Filtek™Z350 was inserted into four layers of 1 mm each and photo-activated. The bond strength was quantitatively evaluated by a microtensile test (1.0 mm/min) 24 h after the restorative procedures. The failure mode was assessed through scanning electron microscopy (SEM). There was a significant reduction in the bond strength of the restored teeth immediately after the bleaching (G2). There were no significant differences in enamel bond strength between groups G1, G3, and G4. There was a predominance of adhesive and mixed (cohesive + adhesive) failure in all groups. The 7-day-period after the end of the bleaching with 35% hydrogen peroxide was enough to achieve the appropriate values of bond strength to the enamel.

  16. Humidity effects on wire insulation breakdown strength.

    Energy Technology Data Exchange (ETDEWEB)

    Appelhans, Leah

    2013-08-01

    Methods for the testing of the dielectric breakdown strength of insulation on metal wires under variable humidity conditions were developed. Two methods, an ASTM method and the twisted pair method, were compared to determine if the twisted pair method could be used for determination of breakdown strength under variable humidity conditions. It was concluded that, although there were small differences in outcomes between the two testing methods, the non-standard method (twisted pair) would be appropriate to use for further testing of the effects of humidity on breakdown performance. The dielectric breakdown strength of 34G copper wire insulated with double layer Poly-Thermaleze/Polyamide-imide insulation was measured using the twisted pair method under a variety of relative humidity (RH) conditions and exposure times. Humidity at 50% RH and below was not found to affect the dielectric breakdown strength. At 80% RH the dielectric breakdown strength was significantly diminished. No effect for exposure time up to 140 hours was observed at 50 or 80%RH.

  17. Oscillator strengths and transition probabilities for the intercombination transitions in Fe XXII

    International Nuclear Information System (INIS)

    Glass, R.

    1979-01-01

    Oscillator strengths and transition probabilities are evaluated for the intercombination transitions between the 2s 2 2p, 2s 2p 2 and 2p 3 states of Fe XXII using configuration interaction wavefunctions. The fine-structure splittings have also been calculated. Some significant differences with previous calculations are obtained

  18. Large eccentric strength increase using the Copenhagen Adduction exercise in football

    DEFF Research Database (Denmark)

    Ishøi, L; Sørensen, C N; Kaae, N M

    2016-01-01

    (control). EHAD, eccentric hip abduction strength (EHAB), and side-bridge endurance were measured using reliable test procedures at baseline and follow-up by a blinded tester. There was a significant interaction between group and time on EHAD, EHAB, and EHAD/EHAB ratio (P 

  19. Aerobic fitness, muscular strength and obesity in relation to risk of heart failure.

    Science.gov (United States)

    Crump, Casey; Sundquist, Jan; Winkleby, Marilyn A; Sundquist, Kristina

    2017-11-01

    Low physical fitness and obesity have been associated with higher risk of developing heart failure (HF), but their interactive effects are unknown. Elucidation of interactions among these common modifiable factors may help facilitate more effective primary prevention. We conducted a national cohort study to examine the interactive effects of aerobic fitness, muscular strength and body mass index (BMI) among 1 330 610 military conscripts in Sweden during 1969-1997 (97%-98% of all 18-year-old men) on risk of HF identified from inpatient and outpatient diagnoses through 2012 (maximum age 62 years). There were 11 711 men diagnosed with HF in 37.8 million person-years of follow-up. Low aerobic fitness, low muscular strength and obesity were independently associated with higher risk of HF, after adjusting for each other, socioeconomic factors, other chronic diseases and family history of HF. The combination of low aerobic fitness and low muscular strength (lowest vs highest tertiles) was associated with a 1.7-fold risk of HF (95% CI 1.6 to 1.9; pfitness, low muscular strength and obesity at the age of 18 years were independently associated with higher risk of HF in adulthood, with interactive effects between aerobic fitness and muscular strength. These findings suggest that early-life interventions may help reduce the long-term risk of HF and should include both aerobic fitness and muscular strength, even among persons with normal BMI. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  20. Tritium-surface interactions

    International Nuclear Information System (INIS)

    Kirkaldy, J.S.

    1983-06-01

    The report deals broadly with tritium-surface interactions as they relate to a fusion power reactor enterprise, viz., the vacuum chamber, first wall, peripherals, pumping, fuel recycling, isotope separation, repair and maintenance, decontamination and safety. The main emphasis is on plasma-surface interactions and the selection of materials for fusion chamber duty. A comprehensive review of the international (particularly U.S.) research and development is presented based upon a literature review (about 1 000 reports and papers) and upon visits to key laboratories, Sandia, Albuquerque, Sandia, Livermore and EGβG Idaho. An inventory of Canadian expertise and facilities for RβD on tritium-surface interactions is also presented. A number of proposals are made for the direction of an optimal Canadian RβD program, emphasizing the importance of building on strength in both the technological and fundamental areas. A compendium of specific projects and project areas is presented dealing primarily with plasma-wall interactions and permeation, anti-permeation materials and surfaces and health, safety and environmental considerations. Potential areas of industrial spinoff are identified

  1. Weak interactions

    International Nuclear Information System (INIS)

    Ogava, S.; Savada, S.; Nakagava, M.

    1983-01-01

    The problem of the use of weak interaction laws to study models of elementary particles is discussed. The most typical examples of weak interaction is beta-decay of nucleons and muons. Beta-interaction is presented by quark currents in the form of universal interaction of the V-A type. Universality of weak interactions is well confirmed using as examples e- and μ-channels of pion decay. Hypothesis on partial preservation of axial current is applicable to the analysis of processes with pion participation. In the framework of the model with four flavours lepton decays of hadrons are considered. Weak interaction without lepton participation are also considered. Properties of neutral currents are described briefly

  2. Protein-containing nutrient supplementation following strength training enhances the effect on muscle mass, strength, and bone formation in postmenopausal women

    DEFF Research Database (Denmark)

    Holm, Lars; Olesen, Jens L; Matsumoto, Keitaro

    2008-01-01

    .0 +/- 1.4%); nutrient group: 0.953 +/- 0.051 to 0.978 +/- 0.043 g/mm(3) (3.8 +/- 3.4%)] when adjusted for age, body mass index, and BMD at inclusion. Bone formation displayed an interaction (P increased osteocalcin at 24 wk in the nutrient group. In conclusion, we report...... that nutrient supplementation results in superior improvements in muscle mass, muscle strength, femoral neck BMD, and bone formation during 24 wk of strength training. The observed differences following such a short intervention emphasize the significance of postexercise nutrient supply on musculoskeletal......We evaluated the response of various muscle and bone adaptation parameters with 24 wk of strength training in healthy, early postmenopausal women when a nutrient supplement (protein, carbohydrate, calcium, and vitamin D) or a placebo supplement (a minimum of energy) was ingested immediately...

  3. Protein-containing nutrient supplementation following strength training enhances the effect on muscle mass, strength, and bone formation in postmenopausal women

    DEFF Research Database (Denmark)

    Holm, Lars; Olesen, J.L.; Matsumoto, K.

    2008-01-01

    .4%); nutrient group: 0.953 ± 0.051 to 0.978 ± 0.043 g/mm3 (3.8 ± 3.4%)] when adjusted for age, body mass index, and BMD at inclusion. Bone formation displayed an interaction (P increased osteocalcin at 24 wk in the nutrient group. In conclusion, we report that nutrient supplementation...... results in superior improvements in muscle mass, muscle strength, femoral neck BMD, and bone formation during 24 wk of strength training. The observed differences following such a short intervention emphasize the significance of postexercise nutrient supply on musculoskeletal maintenance.......We evaluated the response of various muscle and bone adaptation parameters with 24 wk of strength training in healthy, early postmenopausal women when a nutrient supplement (protein, carbohydrate, calcium, and vitamin D) or a placebo supplement (a minimum of energy) was ingested immediately...

  4. The efficacy of incorporating partial squats in maximal strength training.

    Science.gov (United States)

    Bazyler, Caleb D; Sato, Kimitake; Wassinger, Craig A; Lamont, Hugh S; Stone, Michael H

    2014-11-01

    The purpose of our study was to examine the effects of 2 different training methods on dynamic and isometric measures of maximal strength. Seventeen recreationally trained men (1 repetition maximum [1RM] squat: 146.9 ± 22.4 kg) were assigned to 2 groups: full range of motion (ROM) squat (F) and full ROM with partial ROM squat (FP) for the 7-week training intervention. Repeated measures analysis of variance revealed that there was a statistically significant group-by-time interaction for impulse scaled at 50, 90, and 250 milliseconds at 90° of knee flexion and rate of force development at 200 milliseconds with 120° of knee flexion (p ≤ 0.05). There was also a statistically significant time effect (p ≤ 0.05) for the 1RM squat, 1RM partial squat, isometric squat peak force allometrically scaled (IPFa) 90°, IPFa 120°, and impulse allometrically scaled at 50, 90, 200, and 250 milliseconds at 90° and 120° of knee flexion. Additionally, the FP group achieved statistically larger relative training intensities (%1RM) during the final 3 weeks of training (p ≤ 0.05). There was a trend for FP to improve over F in 1RM squat (+3.1%, d = 0.53 vs. 0.32), 1RM partial squat (+4.7%, d = 0.95 vs. 0.69), IPFa 120° (+5.7%, d = 0.52 vs. 0.12), and impulse scaled at 50, 90, 200, and 250 milliseconds at 90° (+6.3 to 13.2%, d = 0.50-1.01 vs. 0.30-0.57) and 120° (+3.4 to 16.8%, d = 0.45-1.11 vs. 0.08-0.37). These larger effect sizes in the FP group can likely be explained their ability to train at larger relative training intensities during the final 3 weeks of training resulting in superior training adaptations. Our findings suggest that partial ROM squats in conjunction with full ROM squats may be an effective training method for improving maximal strength and early force-time curve characteristics in men with previous strength training experience. Practically, partial squats may be beneficial for strength and power athletes during a strength-speed mesocycle while peaking

  5. Influence of Compositional Variations on Floc Size and Strength

    Science.gov (United States)

    Yin, H.; Tan, X.; Reed, A. H.; Furukawa, Y.; Zhang, G.

    2010-12-01

    Clay-biopolymer micro aggregates or flocs are abundant in waters, including rivers, lakes, and oceans. Owing to their small size and charged surfaces, fine-grained inorganic sediment particles, mainly clays, interact actively with organic substances, such as organic matter and biogenic polymers, to form aggregates or flocs, typically in the size of 10-1000 μm. The flocs in ocean waters are also termed “marine snow”. These flocs are typically porous, tenuous, and soft in nature. During transport in suspension, they may breakdown and decrease in size if the turbulent shear stress exceeds their strength. They may also collide and form larger ones if the shear stress is relatively small. Since flocs of different size and structure settle at different velocities, understanding their strength is also of essential importance for sediment hydrodynamics, transport, and management. Our study focuses on investigating the influence of compositional variations on floc size and strength so that a better understanding of floc dynamics can be achieved. A laser diffraction-based Cilas® particle size and shape analyzer with controllable fluid circulation velocity was employed to conduct floc size measurements and shape imaging, the latter achieved by a high resolution inverted optical microscope, which is also installed with the size analyzer. Totally two clay minerals, kaolinite and illite, were tested as the model inorganic solid skeleton minerals for floc formation, and two biopolymers, anionic xanthan gum and neutral guar gum, were chosen as analogs of naturally occurring organic matter or biopolymers to simulate clay-biopolymer floc formation. Moreover, the concentration of both organic and inorganic phases was varied. The floc breakage or tensile strength was indirectly estimated by the varied fluid flow velocity in the particle size analyzer’s circulation system. For each individual composition, stable flocs were formed by three different fluid circulating velocities

  6. Residual-strength determination in polymetric materials

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, R.M.

    1981-10-01

    Kinetic theory of crack growth is used to predict the residual strength of polymetric materials acted upon by a previous history. Specifically, the kinetic theory is used to characterize the state of growing damage that occurs under a constant-stress (load) state. The load is removed before failure under creep-rupture conditions, and the residual instantaneous strength is determined from the theory by taking account of the damage accumulation under the preceding constant-load history. The rate of change of residual strength is found to be strongest when the duration of the preceding load history is near the ultimate lifetime under that condition. Physical explanations for this effect are given, as are numerical examples. Also, the theoretical prediction is compared with experimental data.

  7. Reflector dowel strength test, Fort St. Vrain

    International Nuclear Information System (INIS)

    Doll, D.W.

    1975-01-01

    The strength of the 44.45 mm (1.75 in.) diameter Fort St. Vrain (FSV) reflector dowel for loads directed radially inward toward the center of the element was measured. For a statically applied load, the strength exceeded 5783 N (1300 lb) in direct shear. This strength remained after load cycling 100 times to 4448 N (1000 lb), 10 times to 4893 N (1100 lb), 10 times to 5338 N (1200 lb), and two times to 5783 N (1300 lb). Typically, the deflection to ultimate failure was approximately 1.0 mm (0.04 in.). At about 3316 N (750 lb) and 0.20 mm (0.008 in.) deflection, one of the webs between the dowel and a coolant hole cracked, apparently redistributing the load. No further failure occurred up to the ultimate load of 5783+ N (1300+ lb)

  8. Mechanical properties of high-strength concrete

    Science.gov (United States)

    Mokhtarzadeh, Alireza

    This report summarizes an experimental program conducted to investigate production techniques and mechanical properties of high strength concrete in general and to provide recommendations for using these concretes in manufacturing precast/prestressed bridge girders. Test variables included total amount and composition of cementitious material (portland cement, fly ash, and silica fume), type and brand of cement, type of silica fume (dry densified and slurry), type and brand of high-range water-reducing admixture, type of aggregate, aggregate gradation, maximum aggregate size, and curing. Tests were conducted to determine the effects of these variables on changes in compressive strength and modulus of elasticity over time, splitting tensile strength, modulus of rupture, creep, shrinkage, and absorption potential (as an indirect indicator of permeability). Also investigated were the effects of test parameters such as mold size, mold material, and end condition. Over 6,300 specimens were cast from approximately 140 mixes over a period of 3 years.

  9. Hip strength and range of motion

    DEFF Research Database (Denmark)

    Mosler, Andrea B.; Crossley, Kay M.; Thorborg, Kristian

    2017-01-01

    Objectives To determine the normal profiles for hip strength and range of motion (ROM) in a professional football league in Qatar, and examine the effect of leg dominance, age, past history of injury, and ethnicity on these profiles. Design Cross-sectional cohort study. Methods Participants...... values are documented for hip strength and range of motion that can be used as reference profiles in the clinical assessment, screening, and management of professional football players. Leg dominance, recent past injury history and ethnicity do not need to be accounted for when using these profiles...... included 394 asymptomatic, male professional football players, aged 18–40 years. Strength was measured using a hand held dynamometer with an eccentric test in side-lying for hip adduction and abduction, and the squeeze test in supine with 45° hip flexion. Range of motion measures included: hip internal...

  10. Creep Strength of Discontinuous Fibre Composites

    DEFF Research Database (Denmark)

    Pedersen, Ole Bøcker

    1974-01-01

    relation between stress and strain rate. Expressions for the interface stress, the creep velocity profile adjacent to the fibres and the creep strength of the composite are derived. Previous results for the creep strength, sc = aVfs0 ( \\frac[( Î )\\dot] [( Î )\\dot] 0 )1/nr1 + 1/n c=Vf001n1+1n in which[( Î...... )\\dot] is the composite creep rate,V f is the fibre volume fraction,sgr 0,epsi 0 andn are the constants in the matrix creep law. The creep strength coefficient agr is found to be very weakly dependent onV f and practically independent ofn whenn is greater than about 6....

  11. Tooth structure and fracture strength of cavities

    DEFF Research Database (Denmark)

    Mondelli, José; Sene, Fábio; Ramos, Renata Pereira

    2007-01-01

    This study evaluated, in vitro, the loss of tooth substance after cavity preparation for direct and indirect restorations and its relationship with fracture strength of the prepared teeth. Sixty sound human maxillary first premolars were assigned to 6 groups (n=10). MOD direct composite cavities......) or 1/2 (Groups III and VI) of the intercuspal distance. Teeth were weighed (digital balance accurate to 0.001 g) before and after preparation to record tooth substance mass lost during cavity preparation. The prepared teeth were submitted to occlusal loading to determine their fracture strength using...... mass loss (13.91%) than composite resin preparations with the same width (10.02%). 1/2-inlay cavities had 21.34% of mass loss versus 16.19% for the 1/2-composite resin cavities. Fracture strength means (in kgf) were: GI = 187.65; GII = 143.62; GIII = 74.10; GIV = 164.22; GV = 101.92; GVI = 50...

  12. Residual-strength determination in polymetric materials

    International Nuclear Information System (INIS)

    Christensen, R.M.

    1981-01-01

    Kinetic theory of crack growth is used to predict the residual strength of polymetric materials acted upon by a previous history. Specifically, the kinetic theory is used to characterize the state of growing damage that occurs under a constant-stress (load) state. The load is removed before failure under creep-rupture conditions, and the residual instantaneous strength is determined from the theory by taking account of the damage accumulation under the preceding constant-load history. The rate of change of residual strength is found to be strongest when the duration of the preceding load history is near the ultimate lifetime under that condition. Physical explanations for this effect are given, as are numerical examples. Also, the theoretical prediction is compared with experimental data

  13. Duality rotations for interacting fields

    International Nuclear Information System (INIS)

    Gaillard, M.K.; Zumino, Bruno

    1981-05-01

    We study the properties of interacting field theories which are invariant under duality rotations which transform a vector field strength into its dual. We consider non-abelian duality groups and find that the largest group for n interacting field strengths is the non-compact Sp(2n,R), which has U(n) as its maximal compact subgroup. We show that invariance of the equations of motion requires that the Lagrangian change in a particular way under duality. We use this property to demonstrate the existence of conserved currents, the invariance of the energy momentum tensor, and also in the general construction of the Lagrangian. Finally we comment on the existence of zero mass spin one bound states in N=8 supergravity, which possesses a non-compact E 7 dual invariance

  14. Floor interaction

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Krogh, Peter; Ludvigsen, Martin

    2005-01-01

    Within architecture, there is a long tradition of careful design of floors. The design has been concerned with both decorating floors and designing floors to carry information. Ubiquitous computing technology offers new opportunities for designing interactive floors. This paper presents three...... different interactive floor concepts. Through an urban perspective it draws upon the experiences of floors in architecture, and provides a set of design issues for designing interactive floors....

  15. Short-term Periodization Models: Effects on Strength and Speed-strength Performance.

    Science.gov (United States)

    Hartmann, Hagen; Wirth, Klaus; Keiner, Michael; Mickel, Christoph; Sander, Andre; Szilvas, Elena

    2015-10-01

    Dividing training objectives into consecutive phases to gain morphological adaptations (hypertrophy phase) and neural adaptations (strength and power phases) is called strength-power periodization (SPP). These phases differ in program variables (volume, intensity, and exercise choice or type) and use stepwise intensity progression and concomitant decreasing volume, converging to peak intensity (peaking phase). Undulating periodization strategies rotate these program variables in a bi-weekly, weekly, or daily fashion. The following review addresses the effects of different short-term periodization models on strength and speed-strength both with subjects of different performance levels and with competitive athletes from different sports who use a particular periodization model during off-season, pre-season, and in-season conditioning. In most periodization studies, it is obvious that the strength endurance sessions are characterized by repetition zones (12-15 repetitions) that induce muscle hypertrophy in persons with a low performance level. Strictly speaking, when examining subjects with a low training level, many periodization studies include mainly hypertrophy sessions interspersed with heavy strength/power sessions. Studies have demonstrated equal or statistically significant higher gains in maximal strength for daily undulating periodization compared with SPP in subjects with a low to moderate performance level. The relatively short intervention period and the lack of concomitant sports conditioning call into question the practical value of these findings for competitive athletes. Possibly owing to differences in mesocycle length, conditioning programs, and program variables, competitive athletes either maintained or improved strength and/or speed-strength performance by integrating daily undulating periodization and SPP during off-season, pre-season and in-season conditioning. In high-performance sports, high-repetition strength training (>15) should be

  16. Screen time viewing behaviors and isometric trunk muscle strength in youth.

    Science.gov (United States)

    Grøntved, Anders; Ried-Larsen, Mathias; Froberg, Karsten; Wedderkopp, Niels; Brage, Søren; Kristensen, Peter Lund; Andersen, Lars Bo; Møller, Niels Christian

    2013-10-01

    The objective of this study was to examine the association of screen time viewing behavior with isometric trunk muscle strength in youth. A cross-sectional study was carried out including 606 adolescents (14-16 yr old) participating in the Danish European Youth Heart Study, a population-based study with assessments conducted in either 1997/1998 or 2003/2004. Maximal voluntary contractions during isometric back extension and abdominal flexion were determined using a strain gauge dynamometer, and cardiorespiratory fitness (CRF) was obtained using a maximal cycle ergometer test. TV viewing time, computer use, and other lifestyle behaviors were obtained by self-report. Analyses of association of screen use behaviors with isometric trunk muscle strength were carried out using multivariable adjusted linear regression. The mean (SD) isometric strength was 0.87 (0.16) N·kg-1. TV viewing, computer use, and total screen time use were inversely associated with isometric trunk muscle strength in analyses adjusted for lifestyle and sociodemographic factors. After further adjustment for CRF and waist circumference, associations remained significant for computer use and total screen time, but TV viewing was only marginally associated with muscle strength after these additional adjustments (-0.05 SD (95% confidence interval, -0.11 to 0.005) difference in strength per 1 h·d-1 difference in TV viewing time, P = 0.08). Each 1 h·d-1 difference in total screen time use was associated with -0.09 SD (95% confidence interval, -0.14 to -0.04) lower isometric trunk muscle strength in the fully adjusted model (P = 0.001). There were no indications that the association of screen time use with isometric trunk muscle strength was attenuated among highly fit individuals (P = 0.91 for CRF by screen time interaction). Screen time use was inversely associated with isometric trunk muscle strength independent of CRF and other confounding factors.

  17. Playful Interaction

    DEFF Research Database (Denmark)

    2003-01-01

    The video Playful Interaction describes a future architectural office, and envisions ideas and concepts for playful interactions between people, materials and appliances in a pervasive and augmented working environment. The video both describes existing developments, technologies and designs...... as well as ideas not yet implemented such as playful modes of interaction with an augmented ball. Playful Interaction has been used as a hybrid of a vision video and a video prototype (1). Externally the video has been used to visualising our new ideas, and internally the video has also worked to inspire...

  18. Making High-Tensile-Strength Amalgam Components

    Science.gov (United States)

    Grugel, Richard

    2008-01-01

    Structural components made of amalgams can be made to have tensile strengths much greater than previously known to be possible. Amalgams, perhaps best known for their use in dental fillings, have several useful attributes, including room-temperature fabrication, corrosion resistance, dimensional stability, and high compressive strength. However, the range of applications of amalgams has been limited by their very small tensile strengths. Now, it has been discovered that the tensile strength of an amalgam depends critically on the sizes and shapes of the particles from which it is made and, consequently, the tensile strength can be greatly increased through suitable choice of the particles. Heretofore, the powder particles used to make amalgams have been, variously, in the form of micron-sized spheroids or flakes. The tensile reinforcement contributed by the spheroids and flakes is minimal because fracture paths simply go around these particles. However, if spheroids or flakes are replaced by strands having greater lengths, then tensile reinforcement can be increased significantly. The feasibility of this concept was shown in an experiment in which electrical copper wires, serving as demonstration substitutes for copper powder particles, were triturated with gallium by use of a mortar and pestle and the resulting amalgam was compressed into a mold. The tensile strength of the amalgam specimen was then measured and found to be greater than 10(exp 4) psi (greater than about 69 MPa). Much remains to be done to optimize the properties of amalgams for various applications through suitable choice of starting constituents and modification of the trituration and molding processes. The choice of wire size and composition are expected to be especially important. Perusal of phase diagrams of metal mixtures could give insight that would enable choices of solid and liquid metal constituents. Finally, whereas heretofore, only binary alloys have been considered for amalgams

  19. Numerical Model of High Strength Concrete

    Science.gov (United States)

    Wang, R. Z.; Wang, C. Y.; Lin, Y. L.

    2018-03-01

    The purpose of this paper is to present a three-dimensional constitutive model based on the concept of equivalent uniaxial strain. closed Menetrey-Willam (CMW) failure surfaces which combined with Menetrey-Willam meridian and the cap model are introduced in this paper. Saenz stress-strain model is applied and adjusted by the ultimate strength parameters from CMW failure surface to reflect the latest stress or strain condition. The high strength concrete (HSC) under tri-axial non-proportional loading is considered and the model in this paper performed a good prediction.

  20. Large quantum dots with small oscillator strength

    DEFF Research Database (Denmark)

    Stobbe, Søren; Schlereth, T.W.; Höfling, S.

    2010-01-01

    We have measured the oscillator strength and quantum efficiency of excitons confined in large InGaAs quantum dots by recording the spontaneous emission decay rate while systematically varying the distance between the quantum dots and a semiconductor-air interface. The size of the quantum dots...... is measured by in-plane transmission electron microscopy and we find average in-plane diameters of 40 nm. We have calculated the oscillator strength of excitons of that size assuming a quantum-dot confinement given by a parabolic in-plane potential and a hard-wall vertical potential and predict a very large...... intermixing inside the quantum dots....

  1. Structure of β-decay strength functions

    International Nuclear Information System (INIS)

    Naumov, Y.V.; Bykov, A.A.; Izosimov, I.N.

    1983-01-01

    The experimental and theoretical studies on the structure of the Gamow--Teller β-decay strength functions are reviewed. Also considered are processes such as M1 γ decay of analog states, the emission of delayed protons, neutrons, and α particles, delayed fission, and the (p, n) reaction at proton energies 100--200 MeV. The results of measurements of the strength functions by γ-ray total absorption are analyzed. It is shown that the β + decay of nuclei far from the stability band exhibits a new type of collective charge-exchange excitation: Gamow--Teller resonance with μ/sub tau/ = +1

  2. Compressive strength of thick composite panels

    DEFF Research Database (Denmark)

    Branner, Kim; Berring, Peter

    2011-01-01

    The aim of this study is to investigate how much the compressive strength of thick composite panels is reduced due to delaminations and to investigate under which conditions a delamination will grow. Understanding of this is essential in order to move forward the design limits used in the structu......The aim of this study is to investigate how much the compressive strength of thick composite panels is reduced due to delaminations and to investigate under which conditions a delamination will grow. Understanding of this is essential in order to move forward the design limits used...

  3. Lifetime and residual strength of materials

    DEFF Research Database (Denmark)

    Nielsen, Lauge Fuglsang

    1997-01-01

    of load amplitude, load average, fractional time under maximum load, and load frequency.The analysis includes prediction of residual strength (re-cycle strength) during the process of load cycling. It is concluded that number of cycles to failure is a very poor design criterion. It is demonstrated how...... the theory developed can be generalized also to consider non-harmonic load variations.Algorithms are presented for design purposes which may be suggested as qualified alternatives to the Palmgren-Miner's methods normally used in fatigue analysis of materials under arbitrary load variations. Prediction...

  4. Advanced high strength steels for automotive industry

    Energy Technology Data Exchange (ETDEWEB)

    Galan, J.; Samek, L.; Verleysen, P.; Verbeken, K.; Houbert, Y.

    2012-11-01

    The car industry is facing pressure because of the growing demand for more fuel-efficient passenger cars. In order to limit energy consumption and air pollution the weight of the car body has to be reduced. At the same time, high levels of safety have to be guaranteed. In this situation, the choice of material becomes a key decision in car design. As a response to the requirements of the automotive sector, high strength steels and advanced high strength steels have been developed by the steel industry. These modern steel grades offer an excellent balance of low cost, light weight and mechanical properties. (Author) 48 refs.

  5. Cosmic censorship and the strengths of singularities

    International Nuclear Information System (INIS)

    Newman, R.P.

    1986-01-01

    This paper considers the principal definitions concerning limiting curvature strength on geodesics, and on non-spacelike geodesics in particular. They are formulated in terms of focussing conditions. Two definitions suggest themselves, and these are given in terms of a concept of a generalized Jacobi field. An historical survey is presented on some important developments concerning examples of naked singularities. The historical context is recalled in which these models, and cosmic censorship in general, have arisen. It is the author's opinion that one can expect to obtain theoretical limitations on the strengths of any naked singularities which do occur

  6. Effect of concrete strength gradation to the compressive strength of graded concrete, a numerical approach

    Science.gov (United States)

    Pratama, M. Mirza Abdillah; Aylie, Han; Gan, Buntara Sthenly; Umniati, B. Sri; Risdanareni, Puput; Fauziyah, Shifa

    2017-09-01

    Concrete casting, compacting method, and characteristic of the concrete material determine the performance of concrete as building element due to the material uniformity issue. Previous studies show that gradation in strength exists on building member by nature and negatively influence the load carrying capacity of the member. A pilot research had modeled the concrete gradation in strength with controllable variable and observed that the weakest material determines the strength of graded concrete through uniaxial compressive loading test. This research intends to confirm the recent finding by a numerical approach with extensive variables of strength disparity. The finite element analysis was conducted using the Strand7 nonlinear program. The results displayed that the increase of strength disparity in graded concrete models leads to the slight reduction of models strength. A substantial difference in displacement response is encountered on the models for the small disparity of concrete strength. However, the higher strength of concrete mix in the graded concrete models contributes to the rise of material stiffness that provides a beneficial purpose for serviceability of building members.

  7. Dataset of the relationship between unconfined compressive strength and tensile strength of rock mass

    International Nuclear Information System (INIS)

    Sugita, Yutaka; Yui, Mikazu

    2002-02-01

    This report summary the dataset of the relationship between unconfined compressive strength and tensile strength of the rock mass described in supporting report 2; repository design and engineering technology of second progress report (H12 report) on research and development for the geological disposal of HLW in Japan. (author)

  8. [Loading and strength of single- and multi-unit fixed dental prostheses 2. Strength

    NARCIS (Netherlands)

    Baat, C. de; Witter, D.J.; Meijers, C.C.A.J.; Vergoossen, E.L.; Creugers, N.H.J.

    2014-01-01

    The ultimate strength of a dental prosthesis is defined as the strongest loading force applied to the prosthesis until afracture failure occurs. Important key terms are strength, hardness, toughness and fatigue. Relatively prevalent complications of single- and multi-unit fixed dental prostheses are

  9. The effect of Nordic hamstring strength training on muscle architecture, stiffness, and strength.

    Science.gov (United States)

    Seymore, Kayla D; Domire, Zachary J; DeVita, Paul; Rider, Patrick M; Kulas, Anthony S

    2017-05-01

    Hamstring strain injury is a frequent and serious injury in competitive and recreational sports. While Nordic hamstring (NH) eccentric strength training is an effective hamstring injury-prevention method, the protective mechanism of this exercise is not understood. Strength training increases muscle strength, but also alters muscle architecture and stiffness; all three factors may be associated with reducing muscle injuries. The purpose of this study was to examine the effects of NH eccentric strength training on hamstring muscle architecture, stiffness, and strength. Twenty healthy participants were randomly assigned to an eccentric training group or control group. Control participants performed static stretching, while experimental participants performed static stretching and NH training for 6 weeks. Pre- and post-intervention measurements included: hamstring muscle architecture and stiffness using ultrasound imaging and elastography, and maximal hamstring strength measured on a dynamometer. The experimental group, but not the control group, increased volume (131.5 vs. 145.2 cm 3 , p hamstring strength. The NH intervention was an effective training method for muscle hypertrophy, but, contrary to common literature findings for other modes of eccentric training, did not increase fascicle length. The data suggest that the mechanism behind NH eccentric strength training mitigating hamstring injury risk could be increasing volume rather than increasing muscle length. Future research is, therefore, warranted to determine if muscle hypertrophy induced by NH training lowers future hamstring strain injury risk.

  10. Burst strength of tubing and casing based on twin shear unified strength theory.

    Science.gov (United States)

    Lin, Yuanhua; Deng, Kuanhai; Sun, Yongxing; Zeng, Dezhi; Liu, Wanying; Kong, Xiangwei; Singh, Ambrish

    2014-01-01

    The internal pressure strength of tubing and casing often cannot satisfy the design requirements in high pressure, high temperature and high H2S gas wells. Also, the practical safety coefficient of some wells is lower than the design standard according to the current API 5C3 standard, which brings some perplexity to the design. The ISO 10400: 2007 provides the model which can calculate the burst strength of tubing and casing better than API 5C3 standard, but the calculation accuracy is not desirable because about 50 percent predictive values are remarkably higher than real burst values. So, for the sake of improving strength design of tubing and casing, this paper deduces the plastic limit pressure of tubing and casing under internal pressure by applying the twin shear unified strength theory. According to the research of the influence rule of yield-to-tensile strength ratio and mechanical properties on the burst strength of tubing and casing, the more precise calculation model of tubing-casing's burst strength has been established with material hardening and intermediate principal stress. Numerical and experimental comparisons show that the new burst strength model is much closer to the real burst values than that of other models. The research results provide an important reference to optimize the tubing and casing design of deep and ultra-deep wells.

  11. Fatigue strength of repaired cracks in welded connections made of very high strength steels

    NARCIS (Netherlands)

    Akyel, A.

    2017-01-01

    For cyclically loaded structures, fatigue design becomes one of the important design criteria. The state of art shows that with modification of the conventional structural design methodology, the use of very high strength steels may have a positive effect on fatigue strength of welded connections.

  12. Strengths Weaknesses Opportunities and Threats of Blended ...

    African Journals Online (AJOL)

    students more and that facilitated a more interactive classroom environment. .... link: The evaluation of an innovative and interactive CME program, poster abstracts. ... Picciano A. Blending with purpose: The multimodal model. J Res Cent Educ ...

  13. Correlation between compressive strength and ultrasonic pulse velocity of high strength concrete incorporating chopped basalt fibre

    Science.gov (United States)

    Shafiq, Nasir; Fadhilnuruddin, Muhd; Elshekh, Ali Elheber Ahmed; Fathi, Ahmed

    2015-07-01

    Ultrasonic pulse velocity (UPV), is considered as the most important test for non-destructive techniques that are used to evaluate the mechanical characteristics of high strength concrete (HSC). The relationship between the compressive strength of HSC containing chopped basalt fibre stands (CBSF) and UPV was investigated. The concrete specimens were prepared using a different ratio of CBSF as internal strengthening materials. The compressive strength measurements were conducted at the sample ages of 3, 7, 28, 56 and 90 days; whilst, the ultrasonic pulse velocity was measured at 28 days. The result of HSC's compressive strength with the chopped basalt fibre did not show any improvement; instead, it was decreased. The UPV of the chopped basalt fibre reinforced concrete has been found to be less than that of the control mix for each addition ratio of the basalt fibre. A relationship plot is gained between the cube compressive strength for HSC and UPV with various amounts of chopped basalt fibres.

  14. The assessment of bond strength between heat damaged concrete and high strength fibre reinforced concrete

    Science.gov (United States)

    Zahid, M. Z. A. Mohd; Muhamad, K.

    2017-09-01

    The aim of this study is to assess the bond strength between heat damaged concrete and high strength fibre reinforced concrete (HPFRC). Firstly, this paper presents the various steps taken to prepare the HPFRC with self-compacting property. The minimum targeted slump flow is 600 mm and minimum targeted compressive strength is 80 MPa. The key mix variables considered are such as type of superplasticizer, water cement ratio and silica fume content. Then, the bond strength between the heat damaged concrete with HPFRC was examined. The experimental parameters are heating temperature, surface treatment technique and curing method and the results show that, all experimental parameters are significantly affected the bond strength between heat damaged concrete and HPFRC.

  15. Strength of precast concrete shear joints reinforced with high-strength wire ropes

    DEFF Research Database (Denmark)

    Joergensen, Henrik B.; Hoang, Linh Cao; Hagsten, Lars German

    2017-01-01

    This paper concerns the in-plane shear strength of connections between precast concrete wall elements reinforced with looped high-strength wire ropes. The looped wire ropes are pre-installed in so-called ‘wire boxes’ which function as shear keys. Although only a small amount of research...... on the shear strength of such connections can be found in the literature, this type of connection is increasingly being used because wire ropes are much more construction-friendly than traditional U-bars. A rigid plastic upper bound model for the shear strength of wall connections reinforced with looped wire...... ropes that are pre-installed in wire boxes is presented along with test results on the shear strength of connections with double-wire boxes. It is shown that the plastic solution agrees well with both the obtained test results and results from previously conducted tests....

  16. Study on creep of fiber reinforced ultra-high strength concrete based on strength

    Science.gov (United States)

    Peng, Wenjun; Wang, Tao

    2018-04-01

    To complement the creep performance of ultra-high strength concrete, the long creep process of fiber reinforced concrete was studied in this paper. The long-term creep process and regularity of ultra-high strength concrete with 0.5% PVA fiber under the same axial compression were analyzed by using concrete strength (C80/C100/C120) as a variable. The results show that the creep coefficient of ultra-high strength concrete decreases with the increase of concrete strength. Compared with ACI209R (92), GL2000 models, it is found that the predicted value of ACI209R (92) are close to the experimental value, and the creep prediction model suitable for this experiment is proposed based on ACI209R (92).

  17. Acute Effects of Partial-Body Cryotherapy on Isometric Strength: Maximum Handgrip Strength Evaluation.

    Science.gov (United States)

    De Nardi, Massimo; Pizzigalli, Luisa; Benis, Roberto; Caffaro, Federica; Micheletti Cremasco, Margherita

    2017-12-01

    De Nardi, M, Pizzigalli, L, Benis, R, Caffaro, F, and Cremasco, MM. Acute effects of partial-body cryotherapy on isometric strength: maximum handgrip strength evaluation. J Strength Cond Res 31(12): 3497-3502, 2017-The aim of the study was to evaluate the influence of a single partial-body cryotherapy (PBC) session on the maximum handgrip strength (JAMAR Hydraulic Hand dynamometer). Two hundred healthy adults were randomized into a PBC group and a control group (50 men and 50 women in each group). After the initial handgrip strength test (T0), the experimental group performed a 150-second session of PBC (temperature range between -130 and -160° C), whereas the control group stayed in a thermo neutral room (22.0 ± 0.5° C). Immediately after, both groups performed another handgrip strength test (T1). Data underlined that both groups showed an increase in handgrip strength values, especially the experimental group (Control: T0 = 39.48 kg, T1 = 40.01 kg; PBC: T0 = 39.61 kg, T1 = 41.34 kg). The analysis also reported a statistical effect related to gender (F = 491.99, P ≤ 0.05), with women showing lower handgrip strength values compared with men (women = 30.43 kg, men = 52.27 kg). Findings provide the first evidence that a single session of PBC leads to the improvement of muscle strength in healthy people. The results of the study imply that PBC could be performed also before a training session or a sport competition, to increase hand isometric strength.

  18. Protein fouling in carbon nanotubes enhanced ultrafiltration membrane: Fouling mechanism as a function of pH and ionic strength

    KAUST Repository

    Lee, Jieun; Jeong, Sanghyun; Ye, Yun; Chen, Vicki; Vigneswaran, Saravanamuthu; Leiknes, TorOve; Liu, Zongwen

    2016-01-01

    The protein fouling behavior was investigated in the filtration of the multiwall carbon nanotube (MWCNT) composite membrane and commercial polyethersulfone ultrafiltration (PES-UF) membrane. The effect of solution chemistry such as pH and ionic strength on the protein fouling mechanism was systematically examined using filtration model such as complete pore blocking, intermediate pore blocking and cake layer formation. The results showed that the initial permeate flux pattern and fouling behavior of the MWCNT composite membrane were significantly influenced by pH and ionic strength while the effect of PES-UF membrane on flux was minimal. In a lysozyme (Lys) filtration, the severe pore blocking in the MWCNT membrane was made by the combined effect of intra-foulant interaction (Lys-Lys) and electrostatic repulsion between the membrane surface and the foulant at pH 4.7 and 10.4, and increasing ionic strength where the foulant-foulant interaction and membrane-fouling interaction were weak. In a bovine serum albumin (BSA) filtration, severe pore blocking was reduced by less deposition via the electrostatic interaction between the membrane and foulant at pH 4.7 and 10.4 and increasing ionic strength, at which the interaction between the membrane and BSA became weak. For binary mixture filtration, the protein fouling mechanism was more dominantly affected by foulant-foulant interaction (Lys-BSA, Lys-Lys, and BSA-BSA) at pH 7.0 and increase in ionic strength. This research demonstrates that MWCNT membrane fouling can be alleviated by changing pH condition and ionic strength based on the foulant-foulant interaction and the electrostatic interaction between the membrane and foulant.

  19. Protein fouling in carbon nanotubes enhanced ultrafiltration membrane: Fouling mechanism as a function of pH and ionic strength

    KAUST Repository

    Lee, Jieun

    2016-11-04

    The protein fouling behavior was investigated in the filtration of the multiwall carbon nanotube (MWCNT) composite membrane and commercial polyethersulfone ultrafiltration (PES-UF) membrane. The effect of solution chemistry such as pH and ionic strength on the protein fouling mechanism was systematically examined using filtration model such as complete pore blocking, intermediate pore blocking and cake layer formation. The results showed that the initial permeate flux pattern and fouling behavior of the MWCNT composite membrane were significantly influenced by pH and ionic strength while the effect of PES-UF membrane on flux was minimal. In a lysozyme (Lys) filtration, the severe pore blocking in the MWCNT membrane was made by the combined effect of intra-foulant interaction (Lys-Lys) and electrostatic repulsion between the membrane surface and the foulant at pH 4.7 and 10.4, and increasing ionic strength where the foulant-foulant interaction and membrane-fouling interaction were weak. In a bovine serum albumin (BSA) filtration, severe pore blocking was reduced by less deposition via the electrostatic interaction between the membrane and foulant at pH 4.7 and 10.4 and increasing ionic strength, at which the interaction between the membrane and BSA became weak. For binary mixture filtration, the protein fouling mechanism was more dominantly affected by foulant-foulant interaction (Lys-BSA, Lys-Lys, and BSA-BSA) at pH 7.0 and increase in ionic strength. This research demonstrates that MWCNT membrane fouling can be alleviated by changing pH condition and ionic strength based on the foulant-foulant interaction and the electrostatic interaction between the membrane and foulant.

  20. Calculation of Rydberg interaction potentials

    DEFF Research Database (Denmark)

    Weber, Sebastian; Tresp, Christoph; Menke, Henri

    2017-01-01

    The strong interaction between individual Rydberg atoms provides a powerful tool exploited in an ever-growing range of applications in quantum information science, quantum simulation and ultracold chemistry. One hallmark of the Rydberg interaction is that both its strength and angular dependence...... for calculating the required electric multipole moments and the inclusion of electromagnetic fields with arbitrary direction. We focus specifically on symmetry arguments and selection rules, which greatly reduce the size of the Hamiltonian matrix, enabling the direct diagonalization of the Hamiltonian up...

  1. Quantum Uncertainty and Fundamental Interactions

    Directory of Open Access Journals (Sweden)

    Tosto S.

    2013-04-01

    Full Text Available The paper proposes a simplified theoretical approach to infer some essential concepts on the fundamental interactions between charged particles and their relative strengths at comparable energies by exploiting the quantum uncertainty only. The worth of the present approach relies on the way of obtaining the results, rather than on the results themselves: concepts today acknowledged as fingerprints of the electroweak and strong interactions appear indeed rooted in the same theoretical frame including also the basic principles of special and general relativity along with the gravity force.

  2. Aesthetic interaction

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Iversen, Ole Sejer; Krogh, Peter

    2004-01-01

    , as it promotes aesthetics of use, rather than aesthetics of appearance. We coin this approach in the perspective of aesthetic interaction. Finally we make the point that aesthetics is not re-defining everything known about interactive systems. We provide a framework placing this perspective among other...

  3. Interactive benchmarking

    DEFF Research Database (Denmark)

    Lawson, Lartey; Nielsen, Kurt

    2005-01-01

    We discuss individual learning by interactive benchmarking using stochastic frontier models. The interactions allow the user to tailor the performance evaluation to preferences and explore alternative improvement strategies by selecting and searching the different frontiers using directional...... in the suggested benchmarking tool. The study investigates how different characteristics on dairy farms influences the technical efficiency....

  4. Explicit Interaction

    DEFF Research Database (Denmark)

    Löwgren, Jonas; Eriksen, Mette Agger; Linde, Per

    2006-01-01

    We report an ongoing study of palpable computing to support surgical rehabilitation, in the general field of interaction design for ubiquitous computing. Through explorative design, fieldwork and participatory design techniques, we explore the design principle of explicit interaction as an interp...

  5. Kinesthetic Interaction

    DEFF Research Database (Denmark)

    Fogtmann, Maiken Hillerup; Fritsch, Jonas; Kortbek, Karen Johanne

    2008-01-01

    Within the Human-Computer Interaction community there is a growing interest in designing for the whole body in interaction design. The attempts aimed at addressing the body have very different outcomes spanning from theoretical arguments for understanding the body in the design process, to more...... practical examples of designing for bodily potential. This paper presents Kinesthetic Interaction as a unifying concept for describing the body in motion as a foundation for designing interactive systems. Based on the theoretical foundation for Kinesthetic Interaction, a conceptual framework is introduced...... to reveal bodily potential in relation to three design themes – kinesthetic development, kinesthetic means and kinesthetic disorder; and seven design parameters – engagement, sociality, movability, explicit motivation, implicit motivation, expressive meaning and kinesthetic empathy. The framework is a tool...

  6. The significance of water ionic strength on aluminium toxicity in brown trout (Salmo trutta L.)

    Energy Technology Data Exchange (ETDEWEB)

    Alstad, Nina E.W. [Department of Biology, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo (Norway); Kjelsberg, Birgitte M. [Department of Biology, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo (Norway); Voellestad, L. Asbjoern [Department of Biology, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo (Norway); Lydersen, Espen [Norwegian Institute for Water Research, P.O. Box 173 Kjelsaas, N-0411 Oslo (Norway); Poleo, Antonio B.S. [Department of Biology, University of Oslo, P.O. Box 1066 Blindern, N-0316 Oslo (Norway)]. E-mail: toni.poleo@bio.uio.no

    2005-01-01

    The toxicity of aluminium to fish is related to interactions between aluminium and the gill surface. We investigated the possible effect of water ionic strength on this interaction. The mortality of brown trout (Salmo trutta L.) exposed to three different degrees of Al polymerisation was compared in water with increased ionic strength (mean 7.31 x 10{sup -4} M) after additions of the base cations Ca{sup 2+}, Mg{sup 2+}, Na{sup +} or K{sup +}, and in water with no such addition (mean ionic strength 5.58 x 10{sup -4} M). Only a very slight ameliorating effect of increased ionic strength was observed, while the degree of Al polymerisation was of major importance in fish mortality. In addition, it was observed that smaller fish survived the Al exposures for a longer time than larger fish. We hypothesise that this is because larger fish are more susceptible to hypoxia than smaller fish. - Ionic strength has a slight ameliorating effect on Al toxicity in brown trout.

  7. Computational simulation of coupled material degradation processes for probabilistic lifetime strength of aerospace materials

    Science.gov (United States)

    Boyce, Lola; Bast, Callie C.

    1992-01-01

    The research included ongoing development of methodology that provides probabilistic lifetime strength of aerospace materials via computational simulation. A probabilistic material strength degradation model, in the form of a randomized multifactor interaction equation, is postulated for strength degradation of structural components of aerospace propulsion systems subjected to a number of effects or primative variables. These primative variable may include high temperature, fatigue or creep. In most cases, strength is reduced as a result of the action of a variable. This multifactor interaction strength degradation equation has been randomized and is included in the computer program, PROMISS. Also included in the research is the development of methodology to calibrate the above described constitutive equation using actual experimental materials data together with linear regression of that data, thereby predicting values for the empirical material constraints for each effect or primative variable. This regression methodology is included in the computer program, PROMISC. Actual experimental materials data were obtained from the open literature for materials typically of interest to those studying aerospace propulsion system components. Material data for Inconel 718 was analyzed using the developed methodology.

  8. Relationship between compatibilizer and yield strength of PLA/PP Blend

    Science.gov (United States)

    Jariyakulsith, Pattanun; Puajindanetr, Somchai

    2018-01-01

    The aim of this research is to study the relationship between compatibilizer and yield strength of polylactic acid (PLA) and polypropylene (PP) blend. The PLA is blended with PP (PLA/PP) at the ratios of 70/30, 50/50 and 30/70. In addition, (1) polypropylene grafted maleic anhydride (PP-g-MAH) as a compatibilizer at 0.3 and 0.7 part per hundred of PLA/PP resin (phr) and (2) dicumyl peroxide (DCP) being an initiator at 0.03 and 0.07 phr are added in each composition. Yield strength is characterized to study the interaction between compatibilizer, initiator and yield strength by using experimental design of multilevel full factorial. The results show that (1) the yield strength of PLA/PP blend are increased after addition of compatibilizer. Because the adding of PP-g-MAH and DCP resulted in improving compatibility between PLA and PP. (2) there are interaction between PP-g-MAH and DCP that have affected the final properties of PLA/PP blend. The highest yield strength of 27.68 MPa is provided at the ratio of 70/30 blend by using the 0.3 phr of PP-g-MAH and 0.03 phr of DCP. Linear regression model is fitted and follow the assumptions of normal distribution.

  9. Compressive strength improvement for recycled concrete aggregate

    Directory of Open Access Journals (Sweden)

    Mohammed Dhiyaa

    2018-01-01

    Full Text Available Increasing amount of construction waste and, concrete remnants, in particular pose a serious problem. Concrete waste exist in large amounts, do not decay and need long time for disintegration. Therefore, in this work old demolished concrete is crashed and recycled to produce recycled concrete aggregate which can be reused in new concrete production. The effect of using recycled aggregate on concrete compressive strength has been experimentally investigated; silica fume admixture also is used to improve recycled concrete aggregate compressive strength. The main parameters in this study are recycled aggregate and silica fume admixture. The percent of recycled aggregate ranged from (0-100 %. While the silica fume ranged from (0-10 %. The experimental results show that the average concrete compressive strength decreases from 30.85 MPa to 17.58 MPa when the recycled aggregate percentage increased from 0% to 100%. While, when silica fume is used the concrete compressive strength increase again to 29.2 MPa for samples with 100% of recycled aggregate.

  10. Understanding the Strengths of African American Families.

    Science.gov (United States)

    Littlejohn-Blake, Sheila M.; Darling, Carol Anderson

    1993-01-01

    Focuses on strengths of African-American families and how they function, relevant conceptual approaches, and trends and issues in studying African-American families that can facilitate understanding. A shift from studying dysfunctional families to more positive aspects can help African-American families meet societal challenges. (SLD)

  11. Size Effects on the Strength of Metals

    DEFF Research Database (Denmark)

    Huang, Xiaoxu

    2014-01-01

    The grain size effect and the specimen size effect on the strength of metals are briefly reviewed with respect to their history and current status of research. It is revealed that the fundamental strengthening mechanisms responsible for these two types of size effect are to increase the resistanc...

  12. 7 CFR 29.3061 - Strength (tensile).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Strength (tensile). 29.3061 Section 29.3061 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Official...

  13. 7 CFR 29.6040 - Strength (tensile).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Strength (tensile). 29.6040 Section 29.6040 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Definitions §...

  14. Tensile Strength of the Eggshell Membranes

    Czech Academy of Sciences Publication Activity Database

    Strnková, J.; Nedomová, Š.; Kumbár, V.; Trnka, Jan

    2016-01-01

    Roč. 64, č. 1 (2016), s. 159-164 ISSN 1211-8516 Institutional research plan: CEZ:AV0Z20760514 Institutional support: RVO:61388998 Keywords : eggshell membrane * tesile test * loading rate * tensile strength * fracture strain Subject RIV: GM - Food Processing

  15. A note on integral vortex strength

    Czech Academy of Sciences Publication Activity Database

    Kolář, Václav

    2010-01-01

    Roč. 58, č. 1 (2010), s. 23-28 ISSN 0042-790X R&D Projects: GA AV ČR IAA200600801 Institutional research plan: CEZ:AV0Z20600510 Keywords : circulation * unsteady Taylor vortex * vortex intensity * vortex strength * vorticity * vorticity decomposition Subject RIV: BK - Fluid Dynamics Impact factor: 0.553, year: 2010

  16. 7 CFR 29.2555 - Strength.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Strength. 29.2555 Section 29.2555 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Official Standard Grades...

  17. 7 CFR 29.2303 - Strength.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Strength. 29.2303 Section 29.2303 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Official Standard Grades...

  18. Residual strength evaluation of concrete structural components ...

    Indian Academy of Sciences (India)

    This paper presents methodologies for residual strength evaluation of concrete structural components using linear elastic and nonlinear fracture mechanics principles. The effect of cohesive forces due to aggregate bridging has been represented mathematically by employing tension softening models. Various tension ...

  19. Causal strength induction from time series data.

    Science.gov (United States)

    Soo, Kevin W; Rottman, Benjamin M

    2018-04-01

    One challenge when inferring the strength of cause-effect relations from time series data is that the cause and/or effect can exhibit temporal trends. If temporal trends are not accounted for, a learner could infer that a causal relation exists when it does not, or even infer that there is a positive causal relation when the relation is negative, or vice versa. We propose that learners use a simple heuristic to control for temporal trends-that they focus not on the states of the cause and effect at a given instant, but on how the cause and effect change from one observation to the next, which we call transitions. Six experiments were conducted to understand how people infer causal strength from time series data. We found that participants indeed use transitions in addition to states, which helps them to reach more accurate causal judgments (Experiments 1A and 1B). Participants use transitions more when the stimuli are presented in a naturalistic visual format than a numerical format (Experiment 2), and the effect of transitions is not driven by primacy or recency effects (Experiment 3). Finally, we found that participants primarily use the direction in which variables change rather than the magnitude of the change for estimating causal strength (Experiments 4 and 5). Collectively, these studies provide evidence that people often use a simple yet effective heuristic for inferring causal strength from time series data. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  20. Computer Simulation in Problems of Thermal Strength

    Directory of Open Access Journals (Sweden)

    Olga I. Chelyapina

    2012-05-01

    Full Text Available This article discusses informative technology of using graphical programming environment LabVIEW 2009 when calculating and predicting the thermal strength of materials with an inhomogeneous structure. Algorithm for processing the experimental data was developed as part of the problem.

  1. The statistical strength of nonlocality proofs

    NARCIS (Netherlands)

    Dam, van W.; Gill, R.D.; Grünwald, P.D.

    2005-01-01

    There exist numerous proofs of Bell's theorem, stating that quantum mechanics is incompatible with local realistic theories of nature. Here the strength of such nonlocality proofs is defined in terms of the amount of evidence against local realism provided by the corresponding experiments.

  2. Relationship between pore structure and compressive strength

    Indian Academy of Sciences (India)

    Properties of concrete are strongly dependent on its pore structure features, porosity being an important one among them. This study deals with developing an understanding of the pore structure-compressive strength relationship in concrete. Several concrete mixtures with different pore structures are proportioned and ...

  3. OPTIMISATION OF COMPRESSIVE STRENGTH OF PERIWINKLE ...

    African Journals Online (AJOL)

    In this paper, a regression model is developed to predict and optimise the compressive strength of periwinkle shell aggregate concrete using Scheffe's regression theory. The results obtained from the derived regression model agreed favourably with the experimental data. The model was tested for adequacy using a student ...

  4. Strength Training. A Key to Athletic Training.

    Science.gov (United States)

    Whiteside, Patricia W.

    Characteristics of an effective strength training program are analyzed and descriptions are offered of different kinds of weight training activities. Comparisons are made between concentric, isometric, eccentric, and isokinetic training methods. The fundamentals and techniques of an exemplary training program are outlined and the organization and…

  5. Noticing Young Children's Mathematical Strengths and Agency

    Science.gov (United States)

    Dockett, Sue; Goff, Wendy

    2013-01-01

    This paper promotes the importance of noticing young children's mathematical strengths. It draws on the philosophical positions of children's rights and competence to propose a shift in the ways in which all involved might notice the mathematical engagement, understandings, experiences and practices of young children. Noticing children's…

  6. Strength variability of single flax fibres

    DEFF Research Database (Denmark)

    Aslan, Mustafa; Chinga-Carrasco, G.; Sørensen, Bent F.

    2011-01-01

    (linear and nonlinear) of the fibres are found to be correlated with the amount of defects. The linear stress–strain curves tend to show a higher tensile strength, a higher Young’s modulus, and a lower strain to failure than the nonlinear curves. Finally, the fibres are found to fracture by a complex...

  7. CANFLEX fuel bundle strength tests (test report)

    International Nuclear Information System (INIS)

    Chang, Seok Kyu; Chung, C. H.; Kim, B. D.

    1997-08-01

    This document outlines the test results for the strength tests of the CANFLEX fuel bundle. Strength tests are performed to determine and verify the amount of the bundle shape distortion which is against the side-stops when the bundles are refuelling. There are two cases of strength test; one is the double side-stop test which simulates the normal bundle refuelling and the other is the single side-stop test which simulates the abnormal refuelling. the strength test specification requires that the fuel bundle against the side-stop(s) simulators for this test were fabricated and the flow rates were controlled to provide the required conservative hydraulic forces. The test rig conditions of 120 deg C, 11.2 MPa were retained for 15 minutes after the flow rate was controlled during the test in two cases, respectively. The bundle loading angles of number 13- number 15 among the 15 bundles were 67.5 deg CCW and others were loaded randomly. After the tests, the bundle shapes against the side-stops were measured and inspected carefully. The important test procedures and measurements were discussed as follows. (author). 5 refs., 22 tabs., 5 figs

  8. Development of Airblast and Soil Strength Instrumentation.

    Science.gov (United States)

    1980-02-01

    and nushing on a small reservior of mercury. The bar jauge , contained within the probe along its axis, wou! have its sensitive end §orm -no 6 2 of the...Figure 44. Gauge Placement for Single trength (rc 3hocked-Mer ium Experiment:;. :2nd "’, w. grout medium. The acceleration of the soil strength , jauge

  9. Structure and Strength in Causal Induction

    Science.gov (United States)

    Griffiths, Thomas L.; Tenenbaum, Joshua B.

    2005-01-01

    We present a framework for the rational analysis of elemental causal induction--learning about the existence of a relationship between a single cause and effect--based upon causal graphical models. This framework makes precise the distinction between causal structure and causal strength: the difference between asking whether a causal relationship…

  10. The strength of primary care in Europe

    NARCIS (Netherlands)

    Kringos, D.S.|info:eu-repo/dai/nl/352077131

    2012-01-01

    This thesis aimed to get insight into the elements that form (the strength of) primary care (PC) in Europe, their determinants and their impact on health care system outcomes. The results strengthen the evidence-base for policymakers to prioritise PC strengthening on the health policy agenda and

  11. Got LEGO Bricks? Children with Spatial Strengths

    Science.gov (United States)

    Mann, Rebecca

    2013-01-01

    Individuals with spatial strengths have preferences for visual ideation, holistic reasoning, and innovation. With the emphasis on verbal skills, American schools rarely provide opportunities for children to excel in these areas. Standardized assessments used to judge achievement do not value reflective thinking and innovation; therefore, students…

  12. Deformed metals - structure, recrystallisation and strength

    DEFF Research Database (Denmark)

    Hansen, Niels; Juul Jensen, Dorte

    2011-01-01

    It is shown how new discoveries and advanced experimental techniques in the last 25 years have led to paradigm shifts in the analysis of deformation and annealing structures of metals and in the way the strength of deformed samples is related to structural parameters. This is described in three...

  13. Quasiparticle pole strength in nuclear matter

    International Nuclear Information System (INIS)

    Poggioli, R.S.; Jackson, A.D.

    1975-01-01

    It is argued that single-particle-like behavior in nuclear matter is much less probable than Brueckner theory suggests. In particular, the quasiparticle pole strength is evaluated for nuclear matter and it is shown that, contrary to the spirit of Brueckner theory, low momentum states play a crucial role in determining the magnitude of z/sub k/sub F/. (auth)

  14. Weight Training for Strength and Power.

    Science.gov (United States)

    President's Council on Physical Fitness and Sports, Washington, DC.

    This paper begins by defining the terms "weight training,""weight lifting,""strength,""power," and "muscular endurance.""Weight training" is differentiated from "weight lifting" and defined as a systematic series of resistance exercises designed to promote physical development and conditioning or to rehabilitate persons who have suffered injury or…

  15. Low lying magnetic dipole strength distribution in 176Hf

    International Nuclear Information System (INIS)

    Kuliev, A. A.; Ertugral, F.; Yakut, H.; Bektasoglu, M.; Guliyev, E.

    2006-01-01

    In this study the scissors mode 1 + states are systematically investigated within the rotational invariant Quasiparticle Random Phase Approximation (QRPA) for 1 76Hf isotopes. We consider the 1 + vibrations generated by the isovector spin-spin interactions and the isoscalar (h 0 ) and isovector (h 1 ) quadrupole type separable forces restoring the broken symmetry by a deformed mean field. It has been shown that restoration of the broken rotational symmetry of the Hamiltonian essentially decreases the B(M1) value of the low lying 1 + states and increases the collectivization of the scissors mode excitations in the spectroscopic energy region. Agreement between the calculated mean excitation energies as well as the summed B(M1) value of the scissors mode excitations and the available experimental data of 1 76Hf is rather good. For instance, distributions of the calculated B(M1) transition strengths in the 1 76 Hf isotopes with respect to K π =1 + excitations is represented in Figure. Thus, we see that the models which use the Hamiltonian with broken rotational symmetry strongly overestimate the M1 strength at low energy. These results indicate an importance of the models which are free from the low-energy spurious states. The marked differences between the results for 1 + states, calculated in rotational invariant (RI) and non-rotational invariant (NRI) model indicate the importance of the approaches which are free from spurious low-energy solutions. A separation of the rotational state from the 1 + states changes somewhat the distribution of the B(M1) strength in the spectroscopic energy region and increases the fragmentation of the scissors mode 1 + excitations in agreement with the experimental data

  16. Experimental investigation of bond strength under high loading rates

    Directory of Open Access Journals (Sweden)

    Michal Mathias

    2015-01-01

    Full Text Available The structural behaviour of reinforced concrete is governed significantly by the transmission of forces between steel and concrete. The bond is of special importance for the overlapping joint and anchoring of the reinforcement, where rigid bond is required. It also plays an important role in the rotational capacity of plastic hinges, where a ductile bond behaviour is preferable. Similar to the mechanical properties of concrete and steel also the characteristics of their interaction changes with the velocity of the applied loading. For smooth steel bars with its main bond mechanisms of adhesion and friction, nearly no influence of loading rate is reported in literature. In contrast, a high rate dependence can be found for the nowadays mainly used deformed bars. For mechanical interlock, where ribs of the reinforcing steel are bracing concrete material surrounding the bar, one reason can be assumed to be in direct connection with the increase of concrete compressive strength. For splitting failure of bond, characterized by the concrete tensile strength, an even higher dynamic increase is observed. For the design of Structures exposed to blast or impact loading the knowledge of a rate dependent bond stress-slip relationship is required to consider safety and economical aspects at the same time. The bond behaviour of reinforced concrete has been investigated with different experimental methods at the University of the Bundeswehr Munich (UniBw and the Joint Research Centre (JRC in Ispra. Both static and dynamic tests have been carried out, where innovative experimental apparatuses have been used. The bond stress-slip relationship and maximum pull-out-forces for varying diameter of the bar, concrete compressive strength and loading rates have been obtained. It is expected that these experimental results will contribute to a better understanding of the rate dependent bond behaviour and will serve for calibration of numerical models.

  17. Comparative study of maximum isometric grip strength in different sports

    Directory of Open Access Journals (Sweden)

    Noé Gomes Borges Junior

    2009-01-01

    Full Text Available http://dx.doi.org/10.5007/1980-0037.2009v11n3p292   The objective of this study was to compare maximum isometric grip strength (Fmaxbetween different sports and between the dominant (FmaxD and non-dominant (FmaxND hand. Twenty-nine male aikido (AI, jiujitsu (JJ, judo (JU and rowing (RO athletes and 21non-athletes (NA participated in the study. The hand strength test consisted of maintainingmaximum isometric grip strength for 10 seconds using a hand dynamometer. The position of the subjects was that suggested by the American Society of Hand Therapy. Factorial 2X5 ANOVA with Bonferroni correction, followed by a paired t test and Tukey test, was used for statistical analysis. The highest Fmax values were observed for the JJ group when using the dominant hand,followed by the JU, RO, AI and NA groups. Variation in Fmax could be attributed to handdominance (30.9%, sports modality (39.9% and the interaction between hand dominance andsport (21.3%. The present results demonstrated significant differences in Fmax between the JJ and AI groups and between the JJ and NA groups for both the dominant and non-dominant hand. Significant differences in Fmax between the dominant and non-dominant hand were only observed in the AI and NA groups. The results indicate that Fmax can be used for comparisonbetween different sports modalities, and to identify differences between the dominant and nondominanthand. Studies involving a larger number of subjects will permit the identification of differences between other modalities.

  18. Spatial chaotic behavior of vortices in type-II superconductors with different pinning strength

    International Nuclear Information System (INIS)

    Lin, H.-T.; Pan, M.; Cheng, C.H.; Cui, Y.J.; Zhao, Y.

    2008-01-01

    Spatial chaotic character in systems where defects are arranged in periodic arrays has been investigated by computer simulation. Due to the high nonlinearity of the vortex-defect interaction, arrangement of the vortices in a periodic pinning array can be chaotic (glassy), depending on the vortex-defect interaction state and vortex-vortex interaction. Two types of disordered vortex states in the system are observed. The type-I disorder arises from the intrinsically chaotic nature of the nonlinear system, existing when the pinning disorder is low and the pinning strength is weak. The type-II disordered state is related to the pinning disorder, which is dominating when both the pinning disorder and the pinning strength are strong

  19. Spatial chaotic behavior of vortices in type-II superconductors with different pinning strength

    Energy Technology Data Exchange (ETDEWEB)

    Lin, H.-T. [Faculty of Information Management, Cheng Shui University, Taiwan (China); Pan, M. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C.H. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney (Australia); Cui, Y.J. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhao, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney (Australia)], E-mail: yzhao@swjtu.edu.cn

    2008-09-15

    Spatial chaotic character in systems where defects are arranged in periodic arrays has been investigated by computer simulation. Due to the high nonlinearity of the vortex-defect interaction, arrangement of the vortices in a periodic pinning array can be chaotic (glassy), depending on the vortex-defect interaction state and vortex-vortex interaction. Two types of disordered vortex states in the system are observed. The type-I disorder arises from the intrinsically chaotic nature of the nonlinear system, existing when the pinning disorder is low and the pinning strength is weak. The type-II disordered state is related to the pinning disorder, which is dominating when both the pinning disorder and the pinning strength are strong.

  20. High-strength mineralized collagen artificial bone

    Science.gov (United States)

    Qiu, Zhi-Ye; Tao, Chun-Sheng; Cui, Helen; Wang, Chang-Ming; Cui, Fu-Zhai

    2014-03-01

    Mineralized collagen (MC) is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal's cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in vivo implantation assay demonstrated good biocompatibility of the material, and in vivo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load-bearing sites.

  1. Microcracking and durability of high strength concretes

    International Nuclear Information System (INIS)

    Yssorche, M.P.

    1995-07-01

    Durability of 28 days compressive strength concrete of 20 to 120 MPa has been studied. The ability of concrete to transport aggressive agents has been determined for four properties: the air permeability, the chloride diffusivity, the water absorption and the carbonation. A chloride migration test for high and very high strength concrete (HSC and VHSC) has been built. The relationship between transport properties and the compressive strength after one and 28 days of humid curing has always the same shape: transport decreases when strength increases. However, transport properties often vary in the ordinary concrete field. Beyond, the domain is much more limited. The relationship between transport properties and strength valid for ordinary concrete can not be simply extrapolated for HSC and VHSC. To determine the part of microcracking of HSC and VHSC, concrete behaviour stored in two mediums has been studied: the ones shaming the storing condition of concrete in auto-desiccation, the others reproducing the storing conditions of concrete in desiccation. Auto-desiccation (measuring relative humidity at balance) and desiccation (measuring mass losses) have been showed. Microcracks and shrinkage strains have been measured. It has been showed that auto-desiccation microcracks proving in HSC or VHSC don't question the durability. Microcracks, as for permeability, do not develop between 28 days and one year. On the contrary, desiccation microcracks observed in HSC and VHSC, increase with transport properties between 28 days and 1.5 year. Thus, a bulk concrete is always more durable than a cover concrete. At last, the good influence of increase of curing of 1 to 28 days on the transport of all concretes has been emphasized. (author)

  2. Osmocapsules for direct measurement of osmotic strength.

    Science.gov (United States)

    Kim, Shin-Hyun; Lee, Tae Yong; Lee, Sang Seok

    2014-03-26

    Monodisperse microcapsules with ultra-thin membranes are microfluidically designed to be highly sensitive to osmotic pressure, thereby providing a tool for the direct measurement of the osmotic strength. To make such osmocapsules, water-in-oil-in-water double-emulsion drops with ultra-thin shells are prepared as templates through emulsification of core-sheath biphasic flow in a capillary microfluidic device. When photocurable monomers are used as the oil phase, the osmocapsules are prepared by in-situ photopolymerization of the monomers, resulting in semipermeable membranes with a relatively large ratio of membrane thickness to capsule radius, approximately 0.02. These osmocapsules are buckled by the outward flux of water when they are subjected to a positive osmotic pressure difference above 125 kPa. By contrast, evaporation-induced consolidation of middle-phase containing polymers enables the production of osmocapsules with a small ratio of membrane thickness to capsule radius of approximately 0.002. Such an ultra-thin membrane with semi-permeability makes the osmocapsules highly sensitive to osmotic pressure; a positive pressure as small as 12.5 kPa induces buckling of the capsules. By employing a set of distinct osmocapsules confining aqueous solutions with different osmotic strengths, the osmotic strength of unknown solutions can be estimated through observation of the capsules that are selectively buckled. This approach provides the efficient measurement of the osmotic strength using only a very small volume of liquid, thereby providing a useful alternative to other measurement methods which use complex setups. In addition, in-vivo measurement of the osmotic strength can be potentially accomplished by implanting these biocompatible osmocapsules into tissue, which is difficult to achieve using conventional methods. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Microtensile bond strength of enamel after bleaching

    Directory of Open Access Journals (Sweden)

    Andréa Dias Neves Lago

    2013-01-01

    Full Text Available Objective: To evaluate the bond strength of a composite resin to the bovine enamel bleached with 35% hydrogen peroxide. It was used an etching-and-rinse adhesive system employed immediately, 7 and 14 days after the bleaching. Materials and Methods: Twenty bovine teeth were randomly distributed into 4 groups (n = 5, 3 experimental and 1 control. G1: Unbleached + restoration 14 days after storage in artificial saliva (control; G2: Bleached + restoration immediately after bleaching; G3: Bleached + restoration 7 days after bleaching; G4: Bleached + restoration 14 days after bleaching. Their buccal enamel surfaces were flattened, and a 25 mm² (5 × 5 mm area from each one of these regions was outlined so as to standardize the experimental region. Universal hybrid composite resin Filtek™Z350 was inserted into four layers of 1 mm each and photo-activated. The bond strength was quantitatively evaluated by a microtensile test (1.0 mm/min 24 h after the restorative procedures. The failure mode was assessed through scanning electron microscopy (SEM. Results: There was a significant reduction in the bond strength of the restored teeth immediately after the bleaching (G2. There were no significant differences in enamel bond strength between groups G1, G3, and G4. There was a predominance of adhesive and mixed (cohesive + adhesive failure in all groups. Conclusion: The 7-day-period after the end of the bleaching with 35% hydrogen peroxide was enough to achieve the appropriate values of bond strength to the enamel.

  4. Analysis of the Optimum Usage of Slag for the Compressive Strength of Concrete.

    Science.gov (United States)

    Lee, Han-Seung; Wang, Xiao-Yong; Zhang, Li-Na; Koh, Kyung-Taek

    2015-03-18

    Ground granulated blast furnace slag is widely used as a mineral admixture to replace partial Portland cement in the concrete industry. As the amount of slag increases, the late-age compressive strength of concrete mixtures increases. However, after an optimum point, any further increase in slag does not improve the late-age compressive strength. This optimum replacement ratio of slag is a crucial factor for its efficient use in the concrete industry. This paper proposes a numerical procedure to analyze the optimum usage of slag for the compressive strength of concrete. This numerical procedure starts with a blended hydration model that simulates cement hydration, slag reaction, and interactions between cement hydration and slag reaction. The amount of calcium silicate hydrate (CSH) is calculated considering the contributions from cement hydration and slag reaction. Then, by using the CSH contents, the compressive strength of the slag-blended concrete is evaluated. Finally, based on the parameter analysis of the compressive strength development of concrete with different slag inclusions, the optimum usage of slag in concrete mixtures is determined to be approximately 40% of the total binder content. The proposed model is verified through experimental results of the compressive strength of slag-blended concrete with different water-to-binder ratios and different slag inclusions.

  5. Emergence, Learning Difficulties, and Misconceptions in Chemistry Undergraduate Students' Conceptualizations of Acid Strength

    Science.gov (United States)

    Tümay, Halil

    2016-03-01

    Philosophical debates about chemistry have clarified that the issue of emergence plays a critical role in the epistemology and ontology of chemistry. In this article, it is argued that the issue of emergence has also significant implications for understanding learning difficulties and finding ways of addressing them in chemistry. Particularly, it is argued that many misconceptions in chemistry may derive from students' failure to consider emergence in a systemic manner by taking into account all relevant factors in conjunction. Based on this argument, undergraduate students' conceptions of acids, and acid strength (an emergent chemical property) were investigated and it was examined whether or not they conceptualized acid strength as an emergent chemical property. The participants were 41 third- and fourth-year undergraduate students. A concept test and semi-structured interviews were used to probe students' conceptualizations and reasoning about acid strength. Findings of the study revealed that the majority of the undergraduate students did not conceptualize acid strength as an emergent property that arises from interactions among multiple factors. They generally focused on a single factor to predict and explain acid strength, and their faulty responses stemmed from their failure to recognize and consider all factors that affect acid strength. Based on these findings and insights from philosophy of chemistry, promoting system thinking and epistemologically sound argumentative discourses among students is suggested for meaningful chemical education.

  6. Soil-roots Strength Performance of Extensive Green Roof by Using Axonopus Compressus

    Science.gov (United States)

    Yusoff, N. A.; Ramli, M. N.; Chik, T. N. T.; Ahmad, H.; Abdullah, M. F.; Kasmin, H.; Embong, Z.

    2016-07-01

    Green roof technology has been proven to provide potential environmental benefits including improved building thermal performance, removal of air pollution and reduced storm water runoff. Installation of green roof also involved soil element usage as a plant growth medium which creates several interactions between both strands. This study was carried out to investigate the soil-roots strength performance of green roof at different construction period up to 4 months. Axonopus compressus (pearl grass) was planted in a ExE test plot with a designated suitable soil medium. Direct shear test was conducted for each plot to determine the soil shear strength according to different construction period. In addition, some basic geotechnical testing also been carried out. The results showed that the shear strength of soil sample increased over different construction period of 1st, 2nd, 3rd and 4th month with average result 3.81 kPa, 5.55 kPa, 6.05 kPa and 6.48 kPa respectively. Shear strength of rooted soil samples was higher than the soil samples without roots (control sample). In conclusion, increment of soil-roots shear strength was due to root growth over the time. The soil-roots shear strength development of Axonopus compressus can be expressed in a linear equation as: y = 0.851x + 3.345, where y = shear stress and x = time.

  7. Unit-Sphere Multiaxial Stochastic-Strength Model Applied to Anisotropic and Composite Materials

    Science.gov (United States)

    Nemeth, Noel, N.

    2013-01-01

    Models that predict the failure probability of brittle materials under multiaxial loading have been developed by authors such as Batdorf, Evans, and Matsuo. These "unit-sphere" models assume that the strength-controlling flaws are randomly oriented, noninteracting planar microcracks of specified geometry but of variable size. This methodology has been extended to predict the multiaxial strength response of transversely isotropic brittle materials, including polymer matrix composites (PMCs), by considering (1) flaw-orientation anisotropy, whereby a preexisting microcrack has a higher likelihood of being oriented in one direction over another direction, and (2) critical strength, or K (sub Ic) orientation anisotropy, whereby the level of critical strength or fracture toughness for mode I crack propagation, K (sub Ic), changes with regard to the orientation of the microstructure. In this report, results from finite element analysis of a fiber-reinforced-matrix unit cell were used with the unit-sphere model to predict the biaxial strength response of a unidirectional PMC previously reported from the World-Wide Failure Exercise. Results for nuclear-grade graphite materials under biaxial loading are also shown for comparison. This effort was successful in predicting the multiaxial strength response for the chosen problems. Findings regarding stress-state interactions and failure modes also are provided.

  8. The impact of obesity on skeletal muscle strength and structure through adolescence to old age.

    Science.gov (United States)

    Tomlinson, D J; Erskine, R M; Morse, C I; Winwood, K; Onambélé-Pearson, Gladys

    2016-06-01

    Obesity is associated with functional limitations in muscle performance and increased likelihood of developing a functional disability such as mobility, strength, postural and dynamic balance limitations. The consensus is that obese individuals, regardless of age, have a greater absolute maximum muscle strength compared to non-obese persons, suggesting that increased adiposity acts as a chronic overload stimulus on the antigravity muscles (e.g., quadriceps and calf), thus increasing muscle size and strength. However, when maximum muscular strength is normalised to body mass, obese individuals appear weaker. This relative weakness may be caused by reduced mobility, neural adaptations and changes in muscle morphology. Discrepancies in the literature remain for maximal strength normalised to muscle mass (muscle quality) and can potentially be explained through accounting for the measurement protocol contributing to muscle strength capacity that need to be explored in more depth such as antagonist muscle co-activation, muscle architecture, a criterion valid measurement of muscle size and an accurate measurement of physical activity levels. Current evidence demonstrating the effect of obesity on muscle quality is limited. These factors not being recorded in some of the existing literature suggest a potential underestimation of muscle force either in terms of absolute force production or relative to muscle mass; thus the true effect of obesity upon skeletal muscle size, structure and function, including any interactions with ageing effects, remains to be elucidated.

  9. Using the reactive strength index modified to evaluate plyometric performance.

    Science.gov (United States)

    Ebben, William P; Petushek, Erich J

    2010-08-01

    The ability to develop force quickly is a requisite ability in most sports. The reactive strength index (RSI) has been developed as a measure of explosive strength and is derived by evaluating jump height divided by ground contact time during the depth jump (DJ). At present, the RSI is typically used to evaluate DJ performance, because it is the only plyometric exercise with an identifiable ground contact time. The purpose of this study was to introduce a modification of the RSI (RSImod) that can be used to evaluate the explosive power of any vertical plyometric exercise. This study will also assess the reliability of the RSImod, evaluate the RSImod of a variety of plyometric exercises, and examine gender differences. Twenty-six men and 23 women served as subjects. Subjects performed 3 repetitions for each of 5 plyometric exercises including the countermovement jump (CMJ), tuck jump, single-leg jump, squat jump, and dumbbell CMJ. Data were analyzed using a 2-way analysis of variance to evaluate differences in RSImod between the plyometric exercise and the interaction between plyometric exercise RSImod and gender. The analysis of RSImod revealed significant main effects for plyometric exercise type (p plyometric exercise type and gender (p > 0.05). Results of pairwise comparisons indicate that the RSImod is statistically different between all plyometric exercises studied. Intraclass correlation coefficients indicate that RSImod is highly reliable for all of the exercises studied. The RSImod offers a highly reliable method of assessing the explosiveness developed during a variety of plyometric exercises.

  10. Sink strengths of dislocations taking into account bulk recombination effects

    International Nuclear Information System (INIS)

    Steinbach, E.

    1988-01-01

    The applicability of the rate theory to describe radiation damage processes is closely associated with the calculation of the various sink strengths. In this connection the effect of bulk recombination is usually neglected, because of the complexity of the problem. For this reason we present in this paper, for the first time, by means of the rigorous elastic-field model of a dislocation embedded in a lossy continuum, analytic expressions for the diffusion flux of irradiation-induced point defects into a dislocation, taking into account the elastic interaction, additional sinks and higher order bulk recombination effects. The resulting self-consistent formulae for the dislocation sink strengths clearly demonstrate the importance of the bulk recombination for the micro-structures of irradiated materials. In conjunction with the Harwell computer code VS5 it became clear that this new dislocation bias also leads to a change in the macrostructural observables. The order of magnitude of this effect emphasizes that neglecting bulk recombination as a general principle is not justified

  11. Effective axial-vector strength and β-decay systematics

    Science.gov (United States)

    Delion, D. S.; Suhonen, J.

    2014-09-01

    We use the weak axial-vector coupling strength g_{\\text{A}} as a key parameter to reproduce simultaneously the available data for both the Gamow-Teller \\beta^- and \\beta^+/\\text{EC} decay rates in nine triplets of isobars with mass numbers A=70,78,100,104,106,110,116,128,130 . We use the proton-neutron quasiparticle random-phase approximation (pnQRPA) with schematic dipole interaction containing particle-particle and particle-hole parts with mass-dependent strengths. Our analysis points to a strongly quenched effective value g_{\\text{A}}\\approx 0.3 , with a relative error of 28%. We then perform a systematic computation of 218 experimentally known \\beta^- and \\beta^+/\\text{EC} decays with quite a remarkable success. The presently extracted value of g_{\\text{A}} should be taken as an effective one, specific for a given nuclear theory framework. Present studies suggest that the effective g_{\\text{A}} is suitable for the description of decay transitions to 1^+ states at moderate excitation, below the Gamow-Teller giant resonance region.

  12. Shear strength behavior of geotextile/geomembrane interfaces

    Directory of Open Access Journals (Sweden)

    Belén M. Bacas

    2015-12-01

    Full Text Available This paper aims to study the shear interaction mechanism of one of the critical geosynthetic interfaces, the geotextile/geomembrane, typically used for lined containment facilities such as landfills. A large direct shear machine is used to carry out 90 geosynthetic interface tests. The test results show a strain softening behavior with a very small dilatancy (<0.5 mm and nonlinear failure envelopes at a normal stress range of 25–450 kPa. The influences of the micro-level structure of these geosynthetics on the macro-level interface shear behavior are discussed in detail. This study has generated several practical recommendations to help professionals to choose what materials are more adequate. From the three geotextiles tested, the thermally bonded monofilament exhibits the best interface shear strength under high normal stress. For low normal stress, however, needle-punched monofilaments are recommended. For the regular textured geomembranes tested, the space between the asperities is an important factor. The closer these asperities are, the better the result achieves. For the irregular textured geomembranes tested, the nonwoven geotextiles made of monofilaments produce the largest interface shear strength.

  13. Strength Gain Properties up to five-year age of high-strength mass concrete

    International Nuclear Information System (INIS)

    Mitarai, Y.; Shigenobu, M.; Hiramine, T.; Inoue, K.; Nakane, S.; Ohike, T.

    1991-01-01

    Genkai No.3 plant of Kyushu Electric Power Co., Inc. presently under construction is a PWR type nuclear power plant with 1180 MW power output, and a prestressed concrete containment vessel (PCCV) was adopted for the reactor. The concrete used for the construction of the PCCV is the mass concrete with the wall thickness of 1.3 m in the general parts of the cylinder, and about 2 m at buttresses. It is the high strength concrete of the specified strength 420 kgf/cm 2 . As the preliminary study for the construction using such high strength mass concrete, the examination was carried out on the strength gain property of structural concrete using full scale simulated members. The various problems in the quality control were contemplated based on the results of the examination, and were reflected to actual construction, designating 13 weeks as the age for strength control, in order to build the concrete structures with high reliability. In this report, the outline of the study on the strength gain up to 5 year age carried out in the preliminary study is discussed. The experimental method, the method of evaluating structural strength, the mixing proportion of concrete and the results are reported. (K.I.)

  14. At-home resistance tubing strength training increases shoulder strength in the trained and untrained limb.

    Science.gov (United States)

    Magnus, C R A; Boychuk, K; Kim, S Y; Farthing, J P

    2014-06-01

    The purpose was to determine if an at-home resistance tubing strength training program on one shoulder (that is commonly used in rehabilitation settings) would produce increases in strength in the trained and untrained shoulders via cross-education. Twenty-three participants were randomized to TRAIN (strength-trained one shoulder; n = 13) or CONTROL (no intervention; n = 10). Strength training was completed at home using resistance tubing and consisted of maximal shoulder external rotation, internal rotation, scaption, retraction, and flexion 3 days/week for 4 weeks. Strength was measured via handheld dynamometry and muscle size measured via ultrasound. For external rotation strength, the trained (10.9 ± 10.9%) and untrained (12.7 ± 9.6%) arm of TRAIN was significantly different than CONTROL (1.6 ± 13.2%; -2.7 ± 12.3%; pooled across arm; P tubing training program on one limb can produce increases in strength in both limbs, and has implications for rehabilitation after unilateral shoulder injuries. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. The Effect of Tempering on Strength Properties and Seed Coat ...

    African Journals Online (AJOL)

    The effect of tempering on seed coat adhesion strength and mechanical strength of sorghum and millet grain kernels was investigated at different tempering durations. Tempering reduced the kernel breaking strength and had significant effect on seed coat adhesion strength. Tempering the grain for 60 minutes at ambient ...

  16. Promoting positive outcomes through strengths interventions : A literature review

    NARCIS (Netherlands)

    Ghielen, S.T.S.; van Woerkom, M.; Meyers, M.C.

    2018-01-01

    This paper reviews studies of strengths interventions published between 2011 and 2016. Strengths interventions aim to promote well-being or other positive outcomes by facilitating strengths identification, and sometimes also strengths use and/or development. The present review provides an overview

  17. Handgrip Strength: Indications of Paternal Inheritance in Three European Regions

    DEFF Research Database (Denmark)

    Cournil, Amandine; Jeune, Bernard; Skytthe, Axel

    2010-01-01

    BACKGROUND: Handgrip strength is an indicator of overall muscle strength. Poor handgrip strength is a risk factor for disability and mortality. We aimed to investigate the pattern of inheritance of handgrip strength in a sample of parent-offspring pairs from three different European regions...

  18. Interseason variability in isokinetic strength and poor correlation with Nordic hamstring eccentric strength in football players.

    Science.gov (United States)

    van Dyk, N; Witvrouw, E; Bahr, R

    2018-04-25

    In elite sport, the use of strength testing to establish muscle function and performance is common. Traditionally, isokinetic strength tests have been used, measuring torque during concentric and eccentric muscle action. A device that measures eccentric hamstring muscle strength while performing the Nordic hamstring exercise is now also frequently used. The study aimed to investigate the variability of isokinetic muscle strength over time, for example, between seasons, and the relationship between isokinetic testing and the new Nordic hamstring exercise device. All teams (n = 18) eligible to compete in the premier football league in Qatar underwent a comprehensive strength assessment during their periodic health evaluation at Aspetar Orthopaedic and Sports Medicine Hospital in Qatar. Isokinetic strength was investigated for measurement error, and correlated to Nordic hamstring exercise strength. Of the 529 players included, 288 players had repeated tests with 1/2 seasons between test occasions. Variability (measurement error) between test occasions was substantial, as demonstrated by the measurement error (approximately 25 Nm, 15%), whether separated by 1 or 2 seasons. Considering hamstring injuries, the same pattern was observed among injured (n = 60) and uninjured (n = 228) players. A poor correlation (r = .35) was observed between peak isokinetic hamstring eccentric torque and Nordic hamstring exercise peak force. The strength imbalance between limbs calculated for both test modes was not correlated (r = .037). There is substantial intraindividual variability in all isokinetic test measures, whether separated by 1 or 2 seasons, irrespective of injury. Also, eccentric hamstring strength and limb-to-limb imbalance were poorly correlated between the isokinetic and Nordic hamstring exercise tests. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. How the global layout of the mask influences masking strength.

    Science.gov (United States)

    Ghose, Tandra; Hermens, Frouke; Herzog, Michael H

    2012-12-10

    In visual backward masking, the perception of a target is influenced by a trailing mask. Masking is usually explained by local interactions between the target and the mask representations. However, recently it has been shown that the global spatial layout of the mask rather than its local structure determines masking strength (Hermens & Herzog, 2007). Here, we varied the mask layout by spatial, luminance, and temporal cues. We presented a vernier target followed by a mask with 25 elements. Performance deteriorated when the length of the two mask elements neighboring the target vernier was doubled. However, when the length of every second mask element was doubled, performance improved. When the luminance of the neighboring elements was doubled, performance also deteriorated but no improvement in performance was observed when every second element had a double luminance. For temporal manipulations, a complex nonmonotonic masking function was observed. Hence, changes in the mask layout by spatial, luminance, and temporal cues lead to highly different results.

  20. Gluon field strength correlation functions within a constrained instanton model

    International Nuclear Information System (INIS)

    Dorokhov, A.E.; Esaibegyan, S.V.; Maximov, A.E.; Mikhailov, S.V.

    2000-01-01

    We suggest a constrained instanton (CI) solution in the physical QCD vacuum which is described by large-scale vacuum field fluctuations. This solution decays exponentially at large distances. It is stable only if the interaction of the instanton with the background vacuum field is small and additional constraints are introduced. The CI solution is explicitly constructed in the ansatz form, and the two-point vacuum correlator of the gluon field strengths is calculated in the framework of the effective instanton vacuum model. At small distances the results are qualitatively similar to the single instanton case; in particular, the D 1 invariant structure is small, which is in agreement with the lattice calculations. (orig.)

  1. Big Data and Health Economics: Strengths, Weaknesses, Opportunities and Threats.

    Science.gov (United States)

    Collins, Brendan

    2016-02-01

    'Big data' is the collective name for the increasing capacity of information systems to collect and store large volumes of data, which are often unstructured and time stamped, and to analyse these data by using regression and other statistical techniques. This is a review of the potential applications of big data and health economics, using a SWOT (strengths, weaknesses, opportunities, threats) approach. In health economics, large pseudonymized databases, such as the planned care.data programme in the UK, have the potential to increase understanding of how drugs work in the real world, taking into account adherence, co-morbidities, interactions and side effects. This 'real-world evidence' has applications in individualized medicine. More routine and larger-scale cost and outcomes data collection will make health economic analyses more disease specific and population specific but may require new skill sets. There is potential for biomonitoring and lifestyle data to inform health economic analyses and public health policy.

  2. Programming Interactivity

    CERN Document Server

    Noble, Joshua

    2012-01-01

    Ready to create rich interactive experiences with your artwork, designs, or prototypes? This is the ideal place to start. With this hands-on guide, you'll explore several themes in interactive art and design-including 3D graphics, sound, physical interaction, computer vision, and geolocation-and learn the basic programming and electronics concepts you need to implement them. No previous experience is necessary. You'll get a complete introduction to three free tools created specifically for artists and designers: the Processing programming language, the Arduino microcontroller, and the openFr

  3. 3D strength surfaces for ankle plantar- and dorsi-flexion in healthy adults: an isometric and isokinetic dynamometry study

    Directory of Open Access Journals (Sweden)

    Sara J. Hussain

    2016-11-01

    Full Text Available Abstract Background The ankle is an important component of the human kinetic chain, and deficits in ankle strength can negatively impact functional tasks such as balance and gait. While peak torque is influenced by joint angle and movement velocity, ankle strength is typically reported for a single angle or movement speed. To better identify deficits and track recovery of ankle strength after injury or surgical intervention, ankle strength across a range of movement velocities and joint angles in healthy adults is needed. Thus, the primary goals of this study were to generate a database of strength values and 3-dimensional strength surface models for plantarflexion (PF and dorsiflexion (DF ankle strength in healthy men and women. Secondary goals were to develop a means to estimate ankle strength percentiles as well as examine predictors of maximal ankle strength in healthy adults. Methods Using an isokinetic dynamometer, we tested PF and DF peak torques at five joint angles (−10° [DF], 0° [neutral], 10° [PF], 20° [PF] and 30° [PF] and six velocities (0°/s, 30°/s, 60°/s, 90°/s, 120°/s and 180°/s in 53 healthy adults. These data were used to generate 3D plots, or “strength surfaces”, for males and females for each direction; surfaces were fit using a logistic equation. We also tested predictors of ankle strength, including height, weight, sex, and self-reported physical activity levels. Results Torque-velocity and torque-angle relationships at the ankle interact, indicating that these relationships are interdependent and best modeled using 3D surfaces. Sex was the strongest predictor of ankle strength over height, weight, and self-reported physical activity levels. 79 to 97 % of the variance in mean peak torque was explained by joint angle and movement velocity using logistic equations, for men and women and PF and DF directions separately. Conclusions The 3D strength data and surface models provide a more comprehensive dataset

  4. 3D strength surfaces for ankle plantar- and dorsi-flexion in healthy adults: an isometric and isokinetic dynamometry study.

    Science.gov (United States)

    Hussain, Sara J; Frey-Law, Laura

    2016-01-01

    The ankle is an important component of the human kinetic chain, and deficits in ankle strength can negatively impact functional tasks such as balance and gait. While peak torque is influenced by joint angle and movement velocity, ankle strength is typically reported for a single angle or movement speed. To better identify deficits and track recovery of ankle strength after injury or surgical intervention, ankle strength across a range of movement velocities and joint angles in healthy adults is needed. Thus, the primary goals of this study were to generate a database of strength values and 3-dimensional strength surface models for plantarflexion (PF) and dorsiflexion (DF) ankle strength in healthy men and women. Secondary goals were to develop a means to estimate ankle strength percentiles as well as examine predictors of maximal ankle strength in healthy adults. Using an isokinetic dynamometer, we tested PF and DF peak torques at five joint angles (-10° [DF], 0° [neutral], 10° [PF], 20° [PF] and 30° [PF]) and six velocities (0°/s, 30°/s, 60°/s, 90°/s, 120°/s and 180°/s) in 53 healthy adults. These data were used to generate 3D plots, or "strength surfaces", for males and females for each direction; surfaces were fit using a logistic equation. We also tested predictors of ankle strength, including height, weight, sex, and self-reported physical activity levels. Torque-velocity and torque-angle relationships at the ankle interact, indicating that these relationships are interdependent and best modeled using 3D surfaces. Sex was the strongest predictor of ankle strength over height, weight, and self-reported physical activity levels. 79 to 97 % of the variance in mean peak torque was explained by joint angle and movement velocity using logistic equations, for men and women and PF and DF directions separately. The 3D strength data and surface models provide a more comprehensive dataset of ankle strength in healthy adults than previously reported. These

  5. Quantitative evaluation of the mechanical strength of titanium/composite bonding using laser-generated shock waves

    Science.gov (United States)

    Ducousso, M.; Bardy, S.; Rouchausse, Y.; Bergara, T.; Jenson, F.; Berthe, L.; Videau, L.; Cuvillier, N.

    2018-03-01

    Intense acoustic shock waves were applied to evaluate the mechanical strength of structural epoxy bonds between a TA6V4 titanium alloy and a 3D woven carbon/epoxy composite material. Two bond types with different mechanical strengths were obtained from two different adhesive reticulations, at 50% and 90% of conversion, resulting in longitudinal static strengths of 10 and 39 MPa and transverse strengths of 15 and 35 MPa, respectively. The GPa shock waves were generated using ns-scale intense laser pulses and reaction principles to a confined plasma expansion. Simulations taking into account the laser-matter interaction, plasma relaxation, and non-linear shock wave propagation were conducted to aid interpretation of the experiments. Good correlations were obtained between the experiments and the simulation and between different measurement methods of the mechanical strength (normalized tests vs laser-generated shock waves). Such results open the door toward certification of structural bonding.

  6. Similar strength of the NH⋯O and NH⋯S hydrogen bonds in binary complexes

    DEFF Research Database (Denmark)

    Andersen, Cecilie Lindholm; Jensen, Christine S.; Mackeprang, Kasper

    2014-01-01

    to be extremely small with only 5 and 19 cm-1 for DMA-DME and DMA-DMS, respectively. The experimentally determined integrated absorbance has been combined with a calculated oscillator strength to determine an equilibrium constant of 2 × 10-3 and 4 × 10-3 for the DMA-DME and DMA-DMS complexes, respectively....... The topological analyses reveal that several hydrogen bond interactions are present in the complexes. The calculated binding energies, geometric parameters, observed redshifts, and topological analyses suggest that oxygen and sulfur are hydrogen bond acceptors of similar strength. (Graph Presented)....

  7. Gamow-Teller strength distributions and electron capture rates for 55Co and 56Ni

    International Nuclear Information System (INIS)

    Nabi, Jameel-Un; Rahman, Muneeb-Ur

    2005-01-01

    The Gamow-Teller strength (GT) distributions and electron capture rates on 55 Co and 56 Ni have been calculated using the proton-neutron quasiparticle random phase approximation theory. We calculate these weak interaction mediated rates over a wide temperature (0.01x10 9 -30x10 9 K) and density (10-10 11 gcm -3 ) domain. Electron capture process is one of the essential ingredients involved in the complex dynamics of supernova explosion. Our calculations of electron capture rates show differences with the reported shell model diagonalization approach calculations and are comparatively enhanced at presupernova temperatures. We note that the GT strength is fragmented over many final states

  8. Single cell adhesion strength assessed with variable-angle total internal reflection fluorescence microscopy

    Directory of Open Access Journals (Sweden)

    Marcelina Cardoso Dos Santos

    2017-06-01

    Full Text Available We propose a new strategy to evaluate adhesion strength at the single cell level. This approach involves variable-angle total internal reflection fluorescence microscopy to monitor in real time the topography of cell membranes, i.e. a map of the membrane/substrate separation distance. According to the Boltzmann distribution, both potential energy profile and dissociation energy related to the interactions between the cell membrane and the substrate were determined from the membrane topography. We have highlighted on glass substrates coated with poly-L-lysine and fibronectin, that the dissociation energy is a reliable parameter to quantify the adhesion strength of MDA-MB-231 motile cells.

  9. Tensile strength/yield strength (TS/YS) ratios of high-strength steel (HSS) reinforcing bars

    Science.gov (United States)

    Tavio, Anggraini, Retno; Raka, I. Gede Putu; Agustiar

    2018-05-01

    The building codes such as American Concrete Institute (ACI) 318M-14 and Standard National Indonesia (SNI) 2847:2013 require that the ratio of tensile strength (TS) and yield strength (YS) should not less than 1.25. The requirement is based on the assumption that a capability of a structural member to develop inelastic rotation capacity is a function of the length of the yield region. This paper reports an investigation on various steel grades, namely Grades 420, 550, 650, and 700 MPa, to examine the impact of different TS/YS ratios if it is less or greater than the required value. Grades 550, 650, and 700 MPa were purposely selected with the intention to examine if these higher grades are still promising to be implemented in special structural systems since they are prohibited by the building codes for longitudinal reinforcement, whereas Grade 420 MPa bars are the maximum limit of yield strength of reinforcing bars that is allowable for longitudinal reinforcement of special structural systems. Tensile tests of these steel samples were conducted under displacement controlled mode to capture the complete stress-strain curves and particularly the post-yield response of the steel bars. From the study, it can be concluded that Grade 420 performed higher TS/YS ratios and they were able to reach up to more than 1.25. However, the High Strength Still (HSS) bars (Grades 550, 600, and 700 MPa) resulted in lower TS/YS ratios (less than 1.25) compared with those of Grade 420 MPa.

  10. Interaction graphs

    DEFF Research Database (Denmark)

    Seiller, Thomas

    2016-01-01

    Interaction graphs were introduced as a general, uniform, construction of dynamic models of linear logic, encompassing all Geometry of Interaction (GoI) constructions introduced so far. This series of work was inspired from Girard's hyperfinite GoI, and develops a quantitative approach that should...... be understood as a dynamic version of weighted relational models. Until now, the interaction graphs framework has been shown to deal with exponentials for the constrained system ELL (Elementary Linear Logic) while keeping its quantitative aspect. Adapting older constructions by Girard, one can clearly define...... "full" exponentials, but at the cost of these quantitative features. We show here that allowing interpretations of proofs to use continuous (yet finite in a measure-theoretic sense) sets of states, as opposed to earlier Interaction Graphs constructions were these sets of states were discrete (and finite...

  11. Embarrassing Interactions

    DEFF Research Database (Denmark)

    Deterding, Sebastian; Lucero, Andrés; Holopainen, Jussi

    2015-01-01

    Wherever the rapid evolution of interactive technologies disrupts standing situational norms, creates new, often unclear situational audiences, or crosses cultural boundaries, embarrassment is likely. This makes embarrassment a fundamental adoption and engagement hurdle, but also a creative design...

  12. Diffractive interactions

    International Nuclear Information System (INIS)

    Del Duca, V.; Marage, P.

    1996-08-01

    The general framework of diffractive deep inelastic scattering is introduced and reports given in the session on diffractive interactions at the international workshop on deep-inelastic scattering and related phenomena, Rome, April 1996, are presented. (orig.)

  13. Hip adduction and abduction strength profiles in elite soccer players

    DEFF Research Database (Denmark)

    Thorborg, Kristian; Serner, Andreas; Petersen, Jesper

    2011-01-01

    An ipsilateral hip adduction/abduction strength ratio of more than 90%, and hip adduction strength equal to that of the contralateral side have been suggested to clinically represent adequate strength recovery of hip adduction strength in athletes after groin injury. However, to what extent side-......-to-side symmetry in isometric hip adduction and abduction strength can be assumed in soccer players remains uncertain....

  14. Self-perceived strengths among people who are homeless

    OpenAIRE

    Tweed, Roger G.; Biswas-Diener, Robert; Lehman, Darrin R.

    2012-01-01

    This study examined self-perceived strengths among 116 people who were homeless. Those who had experienced a longer period of current homelessness tended to report fewer personal strengths (r = −0.23). Nonetheless, in spite of their marginalized position in society, the vast majority of participants (114 out of 116) perceived personal strengths. A prior diagnosis with mental illness was not associated with the number of strengths reported, but self-perception of strengths was associated with ...

  15. Interaction Widget

    DEFF Research Database (Denmark)

    Ingstrup, Mads

    2003-01-01

    This pattern describes the idea of making a user interface of discrete, reusable entities---here called interaction widgets. The idea behind widgets is described using two perspectives, that of the user and that of the developer. It is the forces from these two perspectives that are balanced...... in the pattern. The intended audience of the pattern is developers and researchers within the field of human computer interaction....

  16. Hair Interactions

    OpenAIRE

    Cani , Marie-Paule; Bertails , Florence

    2006-01-01

    International audience; Processing interactions is one of the main challenges in hair animation. Indeed, in addition to the collisions with the body, an extremely large number of contacts with high friction rates are permanently taking place between individual hair strands. Simulating the latter is essential: without hair self-interactions, strands would cross each other during motion or come to rest at the same location, yielding unrealistic behavior and a visible lack of hair volume. This c...

  17. Critical behavior in graphene with Coulomb interactions.

    Science.gov (United States)

    Wang, Jianhui; Fertig, H A; Murthy, Ganpathy

    2010-05-07

    We demonstrate that, in the presence of Coulomb interactions, electrons in graphene behave like a critical system, supporting power law correlations with interaction-dependent exponents. An asymptotic analysis shows that the origin of this behavior lies in particle-hole scattering, for which the Coulomb interaction induces anomalously close approaches. With increasing interaction strength the relevant power law changes from real to complex, leading to an unusual instability characterized by a complex-valued susceptibility in the thermodynamic limit. Measurable quantities, as well as the connection to classical two-dimensional systems, are discussed.

  18. High-Tensile Strength Tape Versus High-Tensile Strength Suture: A Biomechanical Study.

    Science.gov (United States)

    Gnandt, Ryan J; Smith, Jennifer L; Nguyen-Ta, Kim; McDonald, Lucas; LeClere, Lance E

    2016-02-01

    To determine which suture design, high-tensile strength tape or high-tensile strength suture, performed better at securing human tissue across 4 selected suture techniques commonly used in tendinous repair, by comparing the total load at failure measured during a fixed-rate longitudinal single load to failure using a biomechanical testing machine. Matched sets of tendon specimens with bony attachments were dissected from 15 human cadaveric lower extremities in a manner allowing for direct comparison testing. With the use of selected techniques (simple Mason-Allen in the patellar tendon specimens, whip stitch in the quadriceps tendon specimens, and Krackow stitch in the Achilles tendon specimens), 1 sample of each set was sutured with a 2-mm braided, nonabsorbable, high-tensile strength tape and the other with a No. 2 braided, nonabsorbable, high-tensile strength suture. A total of 120 specimens were tested. Each model was loaded to failure at a fixed longitudinal traction rate of 100 mm/min. The maximum load and failure method were recorded. In the whip stitch and the Krackow-stitch models, the high-tensile strength tape had a significantly greater mean load at failure with a difference of 181 N (P = .001) and 94 N (P = .015) respectively. No significant difference was found in the Mason-Allen and simple stitch models. Pull-through remained the most common method of failure at an overall rate of 56.7% (suture = 55%; tape = 58.3%). In biomechanical testing during a single load to failure, high-tensile strength tape performs more favorably than high-tensile strength suture, with a greater mean load to failure, in both the whip- and Krackow-stitch models. Although suture pull-through remains the most common method of failure, high-tensile strength tape requires a significantly greater load to pull-through in a whip-stitch and Krakow-stitch model. The biomechanical data obtained in the current study indicates that high-tensile strength tape may provide better repair

  19. The cation-π interaction.

    Science.gov (United States)

    Dougherty, Dennis A

    2013-04-16

    The chemistry community now recognizes the cation-π interaction as a major force for molecular recognition, joining the hydrophobic effect, the hydrogen bond, and the ion pair in determining macromolecular structure and drug-receptor interactions. This Account provides the author's perspective on the intellectual origins and fundamental nature of the cation-π interaction. Early studies on cyclophanes established that water-soluble, cationic molecules would forego aqueous solvation to enter a hydrophobic cavity if that cavity was lined with π systems. Important gas phase studies established the fundamental nature of the cation-π interaction. The strength of the cation-π interaction (Li(+) binds to benzene with 38 kcal/mol of binding energy; NH4(+) with 19 kcal/mol) distinguishes it from the weaker polar-π interactions observed in the benzene dimer or water-benzene complexes. In addition to the substantial intrinsic strength of the cation-π interaction in gas phase studies, the cation-π interaction remains energetically significant in aqueous media and under biological conditions. Many studies have shown that cation-π interactions can enhance binding energies by 2-5 kcal/mol, making them competitive with hydrogen bonds and ion pairs in drug-receptor and protein-protein interactions. As with other noncovalent interactions involving aromatic systems, the cation-π interaction includes a substantial electrostatic component. The six (four) C(δ-)-H(δ+) bond dipoles of a molecule like benzene (ethylene) combine to produce a region of negative electrostatic potential on the face of the π system. Simple electrostatics facilitate a natural attraction of cations to the surface. The trend for (gas phase) binding energies is Li(+) > Na(+) > K(+) > Rb(+): as the ion gets larger the charge is dispersed over a larger sphere and binding interactions weaken, a classical electrostatic effect. On other hand, polarizability does not define these interactions. Cyclohexane is

  20. Frictional strength of wet and dry montmorillonite

    Science.gov (United States)

    Morrow, C. A.; Moore, D. E.; Lockner, D. A.

    2017-05-01

    Montmorillonite is a common mineral in fault zones, and its low strength relative to other common gouge minerals is important in many models of fault rheology. However, the coefficient of friction, μ, varies with degree of saturation and is not well constrained in the literature due to the difficulty of establishing fully drained or fully dried states in the laboratory. We measured μ of both saturated and oven-dried montmorillonite at normal stresses up to 700 MPa. Care was taken to shear saturated samples slowly enough to avoid pore fluid overpressure. For saturated samples, μ increased from 0.10 to 0.28 with applied effective normal stress, while for dry samples μ decreased from 0.78 to 0.45. The steady state rate dependence of friction, (a - b), was positive, promoting stable sliding. The wide disparity in reported frictional strengths can be attributed to experimental procedures that promote differing degrees of partial saturation or overpressured pore fluid conditions.