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2. Rapid processing of neutral and angry expressions within ongoing facial stimulus streams: Is it all about isolated facial features?

Author

Schettino, A. (Antonio), Porcu, E. (Emanuele), Gundlach, C. (Christopher), Keitel, C. (Christian), Müller, M.M. (Matthias M.), Schettino, A. (Antonio), Porcu, E. (Emanuele), Gundlach, C. (Christopher), Keitel, C. (Christian), and Müller, M.M. (Matthias M.)

Abstract

Our visual system extracts the emotional meaning of human facial expressions rapidly and automatically. Novel paradigms using fast periodic stimulations have provided insights into the electrophysiological processes underlying emotional content extraction: the regular occurrence of specific identities and/or emotional expressions alone can drive diagnostic brain responses. Consistent with a processing advantage for social cues of threat, we expected angry facial expressions to drive larger responses than neutral expressions. In a series of four EEG experiments, we studied the potential boundary conditions of such an effect: (i) we piloted emotional cue extraction using 9 facial identities and a fast presentation rate of 15 Hz (N = 16); (ii) we reduced the facial identities from 9 to 2, to assess whether (low or high) variability across emotional expressions would modulate brain responses (N = 16); (iii) we slowed the presentation rate from 15 Hz to 6 Hz (N = 31), the optimal presentation rate for facial feature extraction; (iv) we tested whether passive viewing instead of a concurrent task at fixation would play a role (N = 30). We consistently observed neural responses reflecting the rate of regularly presented emotional

Published
2020
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7. Quantification of mineral behavior in four dimensions : grain boundary and substructure dynamics in salt

Author

Borthwick, Verity E., Schmidt, S., Piazolo, Sandra, Gundlach, C., Borthwick, Verity E., Schmidt, S., Piazolo, Sandra, and Gundlach, C.

Abstract

Here we present the first four dimensional (time and three dimensional space resolved) experiment on a strongly deformed geological material. Results show that even complicated microstructures with large continuous and discontinuous changes in crystallographic orientation can be resolved quantitatively. The details that can be resolved are unprecedented and therefore the presented technique promises to become influential in a wide range of geoscientific investigations. Grain and subgrain scale processes are fundamental to mineral deformation and associated Earth Dynamics, and time resolved observation of these processes is vital for establishing an in-depth understanding of the latter. However, until recently, in situ experiments were restricted to observations of two dimensional surfaces. We compared experimental results from two dynamic, in situ annealing experiments on a single halite crystal; a 2D experiment conducted inside the scanning electron microscope and a 3D X-ray diffraction experiment. This allowed us to evaluate the possible effects of the free surface on grain and subgrain processes. The extent to which surface effects cause experimental artifacts in 2D studies has long been questioned. Our study shows that, although the nature of recovery processes are the same, the area swept by subgrain boundaries is up to 5 times larger in the volume than observed on the surface. We suggest this discrepancy is due to enhanced drag force on subgrain boundaries by thermal surface grooving. Our results show that while it is problematic to derive absolute mobilities from 2D experiments, derived relative mobilities between boundaries with different misorientation angles can be used., AuthorCount:4

Published
2012
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8. McXtrace: A modern ray-tracing package for X-ray instrumentation

Author

Bergbäck Knudsen, Erik, Prodi, A., Willendrup, Peter Kjær, Lefmann, Kim, Baltser, J., Gundlach, C., Del Rio, M. S., Ferrero, C., Feidenhans'l, Robert, Bergbäck Knudsen, Erik, Prodi, A., Willendrup, Peter Kjær, Lefmann, Kim, Baltser, J., Gundlach, C., Del Rio, M. S., Ferrero, C., and Feidenhans'l, Robert

Abstract

we present the developments of the McXtrace project, a free, open source software package based on Monte Carlo ray tracing for simulations and optimisation of complete X-ray instruments. The methodology of building a simulation is presented through an example beamline, namely Beamline 811 at MAX-lab, Lund, Sweden - a beamline dedicated to materials science. © 2011 COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Published
2011

9. McXtrace:a modern ray-tracing package for x-ray instrumentation

Author

Knudsen, E.B., Prodi, Andrea, Willendrup, Peter Kjær, Lefmann, Kim, Baltser, Jana, Gundlach, C., Sanchez del Rio, M., Ferrero, C., Feidenhans'l, Robert Krarup, Knudsen, E.B., Prodi, Andrea, Willendrup, Peter Kjær, Lefmann, Kim, Baltser, Jana, Gundlach, C., Sanchez del Rio, M., Ferrero, C., and Feidenhans'l, Robert Krarup

Published
2011

10. In situ measurements of growth rates and grain-averaged activation energies of individual grains during recrystallization of 50% cold-rolled aluminium

Author

Poulsen, Stefan Othmar, Lauridsen, Erik Mejdal, Lyckegaard, Allan, Oddershede, Jette, Gundlach, C., Curfs, C., Juul Jensen, Dorte, Poulsen, Stefan Othmar, Lauridsen, Erik Mejdal, Lyckegaard, Allan, Oddershede, Jette, Gundlach, C., Curfs, C., and Juul Jensen, Dorte

Abstract

Three-dimensional X-ray diffraction has been used to study the growth kinetics of 1406 individual grains recrystallizing in 50% cold-rolled aluminium. It is found that each grain follows its own kinetics. The radial growth of individual grains is found to often be piecewise linear, and an explanation based on the cell block microstructure of cold-rolled aluminium is proposed. Grain-averaged activation energies of 793 individual grains are determined, and found to constitute a broad distribution. Reasons and implications of these findings are discussed.

Published
2011

11. Critical phenomena in gravitational collapse

Author

Gundlach, C., Martín-García, José María, Gundlach, C., and Martín-García, José María

Abstract

As first discovered by Choptuik, the black hole threshold in the space of initial data for general relativity shows both surprising structure and surprising simplicity. Universality, power-law scaling of the black hole mass, and scale echoing have given rise to the term >critical phenomena>. They are explained by the existence of exact solutions which are attractors within the black hole threshold, that is, attractors of codimension one in phase space, and which are typically self-similar. Critical phenomena give a natural route from smooth initial data to arbitrarily large curvatures visible from infinity, and are therefore likely to be relevant for cosmic censorship, quantum gravity, astrophysics, and our general understanding of the dynamics of general relativity.

Published
2007

12. Formation and subdivision of deformation structures

Author

Jakobsen, B., Poulsen, H.F., Lienert, U., Almer, J., Shastri, S.D., Sørensen, H.O., Gundlach, C., Pantleon, W., Jakobsen, B., Poulsen, H.F., Lienert, U., Almer, J., Shastri, S.D., Sørensen, H.O., Gundlach, C., and Pantleon, W.

Published
2006

13. Hyperbolicity of second order in space systems of evolution equations

Author

Gundlach, C., Martín-García, José María, Gundlach, C., and Martín-García, José María

Abstract

A possible definition of strong/symmetric hyperbolicity for a second-order system of evolution equations is that it admits a reduction to first order which is strongly/symmetric hyperbolic. We investigate the general system that admits a reduction to first order and give necessary and sufficient criteria for strong/symmetric hyperbolicity of the reduction in terms of the principal part of the original second-order system. An alternative definition of strong hyperbolicity is based on the existence of a complete set of characteristic variables, and an alternative definition of symmetric hyperbolicity is based on the existence of a conserved (up to lower-order terms) energy. Both these definitions are made without any explicit reduction. Finally, strong hyperbolicity can be defined through a pseudo-differential reduction to first order. We prove that both definitions of symmetric hyperbolicity are equivalent and that all three definitions of strong hyperbolicity are equivalent (in three space dimensions). We show how to impose maximally dissipative boundary conditions on any symmetric hyperbolic second-order system. We prove that if the second-order system is strongly hyperbolic, any closed constraint evolution system associated with it is also strongly hyperbolic, and that the characteristic variables of the constraint system are derivatives of a subset of the characteristic variables of the main system, with the same speeds. © 2006 IOP Publishing Ltd.

Published
2006

14. Well-posedness of formulations of the Einstein equations with dynamical lapse and shift conditions

Author

Gundlach, C., Martín-García, José María, Gundlach, C., and Martín-García, José María

Abstract

We prove that when the equations are restricted to the principal part the standard version of the Baumgarte-Shapiro-Shibata-Nakamura (BSSN) formulation of the Einstein equations is equivalent to the Nagy-Ortiz-Reula (NOR) formulation for any gauge, and that the Kidder-Scheel-Teukolsky (KST) formulation is equivalent to NOR for a variety of gauges. We review a family of elliptic gauge conditions and the implicit parabolic and hyperbolic drivers that can be derived from them, and show how to make them symmetry-seeking. We investigate the hyperbolicity of Arnowitt-Deser-Misner (ADM), NOR, and BSSN with implicit hyperbolic lapse and shift drivers. We show that BSSN with the coordinate drivers used in recent >moving puncture> binary black hole evolutions is ill-posed at large shifts, and suggest how to make it strongly hyperbolic for arbitrary shifts. For ADM, NOR, and BSSN with elliptic and parabolic gauge conditions, which cannot be hyperbolic, we investigate a necessary condition for well-posedness of the initial-value problem. © 2006 The American Physical Society.

Published
2006

15. Metal Microstructures in Four Dimensions

Author

Nielsen, S. F., Gundlach, C., Lauridsen, E. M., Martins, R. V., Poulsen, H. F., Schmidt, S., Juul Jensen, D., Nielsen, S. F., Gundlach, C., Lauridsen, E. M., Martins, R. V., Poulsen, H. F., Schmidt, S., and Juul Jensen, D.

Abstract

By Three Dimensional X-ray Diffraction (3DXRD) microscopy it is possible to characterize microstructures non-destructively in 3 dimensions. The measurements are furthermore typically so fast that dynamics may be monitored in-situ, giving also the 4'th dimension, namely the time. The 3DXRD technique is based on diffraction of high energy x-rays from third generation synchrotron sources. In the present paper the 3DXRD technique is described and it's potentials are illustrated by examples relating to elastic and plastic strains, recovery, recrystallization and grain growth.

Published
2004

16. Statistical TEM analysis of boundary misorientations in aluminium deformed to large and extra large strains by ECAE

Author

Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Mishin, Oleg, Godfrey, A., Liu, Q., Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Mishin, Oleg, Godfrey, A., and Liu, Q.

Published
2004

17. On the origin and nature of deformation bands in single crystals deformed in tension

Author

Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Wert, John A., Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., and Wert, John A.

Published
2004

18. Evolution of deformation microstructures in 3D. Proceedings

Author

Gundlach, C., Haldrup, Martin Kristoffer, Hansen, Niels, Huang, Xiaoxu, Juul Jensen, Dorte, Leffers, Torben, Li, Z.J., Fæster Nielsen, Søren, Pantleon, Wolfgang, Wert, John A., Winther, Grethe, Gundlach, C., Haldrup, Martin Kristoffer, Hansen, Niels, Huang, Xiaoxu, Juul Jensen, Dorte, Leffers, Torben, Li, Z.J., Fæster Nielsen, Søren, Pantleon, Wolfgang, Wert, John A., and Winther, Grethe

Published
2004

19. Watching the growth of bulk grains during recrystallization of deformed metals

Author

Schmidt, Søren, Fæster Nielsen, Søren, Gundlach, C., Margulies, L., Huang, X., Juul Jensen, D., Schmidt, Søren, Fæster Nielsen, Søren, Gundlach, C., Margulies, L., Huang, X., and Juul Jensen, D.

Abstract

We observed the in situ growth of a grain during recrystallization in the bulk of a deformed sample. We used the three-dimensional x-ray diffraction microscope located at the European Synchrotron Radiation Facility in Grenoble, France. The results showed a very heterogeneous growth pattern, contradicting the classical assumption of smooth and spherical growth of new grains during recrystallization. This type of in situ bulk measurement opens up the possibility of obtaining experimental data on scientific topics that before could only be analyzed theoretically on the basis of the statistical characterization of microstructures. For recrystallization, the in situ method includes direct measurements of nucleation and boundary migration through a deformed matrix.

Published
2004

21. Three-dimensional X-ray diffraction (3DXRD) analysis

Author

Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Margulies, L., Poulsen, H.F., Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Margulies, L., and Poulsen, H.F.

Published
2004

22. Microstructure of metals and alloys deformed to ultrahigh strains

Author

Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Tsuji, N., Nakashima, H., Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Tsuji, N., and Nakashima, H.

Published
2004

23. Local measurements of stored energy: Microstructural and stereological considerations

Author

Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Godfrey, A., Liu, Q., Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Godfrey, A., and Liu, Q.

Published
2004

25. Slip as a mechanism for structural evolution

Author

Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., and Winther, G.

Published
2004

27. Evolving microstructures in carbon steel studied by 3DXRD microscopy

Author

Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Offerman, S.E., Zijden, A.C.P. van der, Dijk, H.N. Van, Sietsma, J., Lauridsen, E.M., Margulies, L., Grigull, S., Poulsen, H.F., Zwaag, S. Van der, Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Offerman, S.E., Zijden, A.C.P. van der, Dijk, H.N. Van, Sietsma, J., Lauridsen, E.M., Margulies, L., Grigull, S., Poulsen, H.F., and Zwaag, S. Van der

Published
2004

28. Microstructural evolution in aluminium (AA1050) plane strain compressed at 0.7 TM

Author

Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Knudsen, T., Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., and Knudsen, T.

Published
2004

29. Observation of dislocation structure evolution by analysis of X-ray peak profiles from individual bulk grains

Author

Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Lienert, U., Almer, J., Jakobsen, B., Poulsen, H.F., Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Lienert, U., Almer, J., Jakobsen, B., and Poulsen, H.F.

Published
2004

30. 3 dimensional microstructures in electrodeposited and cold rolled copper

Author

Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Sui, M.L., Lu, Q.H., Li, D.X., Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Sui, M.L., Lu, Q.H., and Li, D.X.

Published
2004

32. Disorientations and work-hardening in stage IV

Author

Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., and Winther, G.

Published
2004

33. Mechanical effects of 3D morphology of planar dislocation boundaries

Author

Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., and Winther, G.

Published
2004

34. Enhanced structural evolution by martensitic transformation and deformation of IF steels

Author

Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Morito, S., Furuhara, T., Maki, T., Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Morito, S., Furuhara, T., and Maki, T.

Published
2004

35. Study of grain subdivision in aluminium using electron back-scattering diffraction

Author

Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Boxel, S. Van, Seefeldt, M., Verlinden, B., Houtte, P. Van, Gundlach, C., Haldrup, K., Hansen, N., Huang, X., Juul Jensen, D., Leffers, T., Li, Z.J., Nielsen, S.F., Pantleon, W., Wert, J.A., Winther, G., Boxel, S. Van, Seefeldt, M., Verlinden, B., and Houtte, P. Van

Published
2004

38. 3DXRD microscopy (invited talk)

Author

Poulsen, H.F., Fu, X., Gundlach, C., Juul Jensen, D., Lauridsen, E.M., Margulies, L., Fæster Nielsen, Søren, Schmidt, Søren, Vaughan, G., Poulsen, H.F., Fu, X., Gundlach, C., Juul Jensen, D., Lauridsen, E.M., Margulies, L., Fæster Nielsen, Søren, Schmidt, Søren, and Vaughan, G.

Published
2003

42. Automated skid data system.

Author

Runkle, Stephen N, Gundlach, C. T, Virginia Highway & Transportation Research Council, Runkle, Stephen N, Gundlach, C. T, and Virginia Highway & Transportation Research Council

Abstract

The Data Systems and Analysis Section of the Virginia Highway & Transportation Research Council has been involved for sometime in the development of automated information systems for various types of roadway data. One of these systems, and the system discussed in this report, is the one for the collection, storage, and retrieval of skid data collected during normal survey skid testing. Included in this report is a description of the data files maintained for skid data and the computer programs developed to edit input data, maintain the data files, and provide skid data output listings.

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