TY  - GEN
A1  - Niskanen, Johannes
A1  - Kooser, Kuno
A1  - Koskelo, Jaakko
A1  - Käämbre, Tanel
A1  - Kunnus, Kristjan
A1  - Pietzsch, Annette
A1  - Quevedo, Wilson
A1  - Hakala, Mikko
A1  - Föhlisch, Alexander
A1  - Huotari, Simo
A1  - Kukk, Edwin
T1  - Density functional simulation of resonant inelastic X-ray scattering experiments in liquids: acetonitrile
N2  - In this paper we report an experimental and computational study of liquid acetonitrile (H3C–C[triple bond, length as m-dash]N) by resonant inelastic X-ray scattering (RIXS) at the N K-edge. The experimental spectra exhibit clear signatures of the electronic structure of the valence states at the N site and incident-beam-polarization dependence is observed as well. Moreover, we find fine structure in the quasielastic line that is assigned to finite scattering duration and nuclear relaxation. We present a simple and light-to-evaluate model for the RIXS maps and analyze the experimental data using this model combined with ab initio molecular dynamics simulations. In addition to polarization-dependence and scattering-duration effects, we pinpoint the effects of different types of chemical bonding to the RIXS spectrum and conclude that the H2C–C[double bond, length as m-dash]NH isomer, suggested in the literature, does not exist in detectable quantities. We study solution effects on the scattering spectra with simulations in liquid and in vacuum. The presented model for RIXS proved to be light enough to allow phase-space-sampling and still accurate enough for identification of transition lines in physical chemistry research by RIXS.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 331 
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-395133
ER  - 
TY  - GEN
A1  - Nishikawa, Ken-Ichi
A1  - Mizuno, Yosuke
A1  - Niemiec, Jacek
A1  - Kobzar, Oleh
A1  - Pohl, Martin
A1  - Gómez, Jose L.
A1  - Duţan, Ioana
A1  - Pe’er, Asaf
A1  - Frederiksen, Jacob Trier
A1  - Nordlund, Åke
A1  - Meli, Athina
A1  - Sol, Helene
A1  - Hardee, Philip E.
A1  - Hartmann, Dieter H.
T1  - Microscopic processes in global relativistic jets containing helical magnetic fields
T2  - Galaxies
N2  - In the study of relativistic jets one of the key open questions is their interaction with the environment on the microscopic level. Here, we study the initial evolution of both electron-proton (e(-)-p(+)) and electron-positron (e(+/-)) relativistic jets containing helical magnetic fields, focusing on their interaction with an ambient plasma. We have performed simulations of "global" jets containing helical magnetic fields in order to examine how helical magnetic fields affect kinetic instabilities such as the Weibel instability, the kinetic Kelvin-Helmholtz instability (kKHI) and the Mushroom instability (MI). In our initial simulation study these kinetic instabilities are suppressed and new types of instabilities can grow. In the e(-)-p(+) jet simulation a recollimation-like instability occurs and jet electrons are strongly perturbed. In the e(+/-) jet simulation a recollimation-like instability occurs at early times followed by a kinetic instability and the general structure is similar to a simulation without helical magnetic field. Simulations using much larger systems are required in order to thoroughly follow the evolution of global jets containing helical magnetic fields.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 446 
KW  - relativistic jets
KW  - particle-in-cell simulations
KW  - global jets
KW  - helical magnetic fields
KW  - kinetic instabilities
KW  - kink instability
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407604
ER  - 
TY  - JOUR
A1  - Nishikawa, Ken-Ichi
A1  - Mizuno, Yosuke
A1  - Niemiec, Jacek
A1  - Kobzar, Oleh
A1  - Pohl, Martin
A1  - Gomez, Jose L.
A1  - Dutan, Ioana
A1  - Frederiksen, Jacob Trier
A1  - Nordlund, Ake
A1  - Meli, Athina
A1  - Sol, Helene
A1  - Hardee, Philip E.
A1  - Hartmann, Dieter H.
T1  - Microscopic Processes in Global Relativistic Jets Containing Helical Magnetic Fields
JF  - Galaxies : open access journal
N2  - In the study of relativistic jets one of the key open questions is their interaction with the environment on the microscopic level. Here, we study the initial evolution of both electron-proton (e(-)-p(+)) and electron-positron (e(+/-)) relativistic jets containing helical magnetic fields, focusing on their interaction with an ambient plasma. We have performed simulations of "global" jets containing helical magnetic fields in order to examine how helical magnetic fields affect kinetic instabilities such as the Weibel instability, the kinetic Kelvin-Helmholtz instability (kKHI) and the Mushroom instability (MI). In our initial simulation study these kinetic instabilities are suppressed and new types of instabilities can grow. In the e(-)-p(+) jet simulation a recollimation-like instability occurs and jet electrons are strongly perturbed. In the e(+/-) jet simulation a recollimation-like instability occurs at early times followed by a kinetic instability and the general structure is similar to a simulation without helical magnetic field. Simulations using much larger systems are required in order to thoroughly follow the evolution of global jets containing helical magnetic fields.
KW  - relativistic jets
KW  - particle-in-cell simulations
KW  - global jets
KW  - helical magnetic fields
KW  - kinetic instabilities
KW  - kink instability
Y1  - 2016
U6  - https://doi.org/10.3390/galaxies4040038
SN  - 2075-4434
VL  - 4
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Nishikawa, Ken-Ichi
A1  - Frederiksen, J. T.
A1  - Nordlund, A.
A1  - Mizuno, Y.
A1  - Hardee, P. E.
A1  - Niemiec, J.
A1  - Gomez, J. L.
A1  - Dutan, I.
A1  - Meli, A.
A1  - Sol, H.
A1  - Pohl, Martin
A1  - Hartmann, D. H.
T1  - EVOLUTION OF GLOBAL RELATIVISTIC JETS: COLLIMATIONS AND EXPANSION WITH
kKHI AND THE WEIBEL INSTABILITY
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - In the study of relativistic jets one of the key open questions is their interaction with the environment. Here. we study the initial evolution of both electron-proton (e(-) - p(+)) and electron-positron (e(+/-)) relativistic jets, focusing on their lateral interaction with ambient plasma. We follow the evolution of toroidal magnetic fields generated by both the kinetic Kelvin-Helmholtz and Mushroom instabilities. For an e(-) - p(+) jet, the induced magnetic field collimates the jet and electrons are perpendicularly accelerated. As the instabilities saturate and subsequently weaken, the magnetic polarity switches from clockwise to counterclockwise in the middle of the jet. For an e(+/-) jet, we find strong mixing of electrons and positrons with the ambient plasma, resulting in the creation of a bow shock. The merging of current filaments generates density inhomogeneities that. initiate a forward shock. Strong jet-ambient plasma mixing prevents a full development of the jet (on the scale studied), revealing evidence for both jet collimation and particle acceleration in the forming bow shock. Differences in the magnetic field structure generated by e(-) - p(+) and e(+/-) jets may contribute to the polarization properties of the observed emission in AGN jets and gamma-ray bursts.
KW  - acceleration of particles
KW  - plasmas
KW  - radiation mechanisms: non-thermal
KW  - relativistic processes
KW  - stars: jets
KW  - Sun: magnetic fields
Y1  - 2016
U6  - https://doi.org/10.3847/0004-637X/820/2/94
SN  - 0004-637X
SN  - 1538-4357
VL  - 820
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Neher, Dieter
A1  - Kniepert, Juliane
A1  - Elimelech, Arik
A1  - Koster, L. Jan Anton
T1  - A New Figure of Merit for Organic Solar Cells with Transport-limited Photocurrents
JF  - Scientific reports
N2  - Compared to their inorganic counterparts, organic semiconductors suffer from relatively low charge carrier mobilities. Therefore, expressions derived for inorganic solar cells to correlate characteristic performance parameters to material properties are prone to fail when applied to organic devices. This is especially true for the classical Shockley-equation commonly used to describe current-voltage (JV)-curves, as it assumes a high electrical conductivity of the charge transporting material. Here, an analytical expression for the JV-curves of organic solar cells is derived based on a previously published analytical model. This expression, bearing a similar functional dependence as the Shockley-equation, delivers a new figure of merit a to express the balance between free charge recombination and extraction in low mobility photoactive materials. This figure of merit is shown to determine critical device parameters such as the apparent series resistance and the fill factor.
Y1  - 2016
U6  - https://doi.org/10.1038/srep24861
SN  - 2045-2322
VL  - 6
SP  - E2348
EP  - E2349
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - GEN
A1  - Neher, Dieter
A1  - Kniepert, Juliane
A1  - Elimelech, Arik
A1  - Koster, L. Jan Anton
T1  - A New Figure of Merit for Organic Solar Cells with Transport-limited Photocurrents
N2  - Compared to their inorganic counterparts, organic semiconductors suffer from relatively low charge carrier mobilities. Therefore, expressions derived for inorganic solar cells to correlate characteristic performance parameters to material properties are prone to fail when applied to organic devices. This is especially true for the classical Shockley-equation commonly used to describe current-voltage (JV)-curves, as it assumes a high electrical conductivity of the charge transporting material. Here, an analytical expression for the JV-curves of organic solar cells is derived based on a previously published analytical model. This expression, bearing a similar functional dependence as the Shockley-equation, delivers a new figure of merit α to express the balance between free charge recombination and extraction in low mobility photoactive materials. This figure of merit is shown to determine critical device parameters such as the apparent series resistance and the fill factor.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 225 
KW  - Electronic and spintronic devices
KW  - Semiconductors
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-91414
ER  - 
TY  - JOUR
A1  - Neher, Dieter
A1  - Kniepert, Juliane
A1  - Elimelech, Arik
A1  - Koster, L. Jan Anton
T1  - A New Figure of Merit for Organic Solar Cells with Transport-limited Photocurrents
JF  - Scientific reports
N2  - Compared to their inorganic counterparts, organic semiconductors suffer from relatively low charge carrier mobilities. Therefore, expressions derived for inorganic solar cells to correlate characteristic performance parameters to material properties are prone to fail when applied to organic devices. This is especially true for the classical Shockley-equation commonly used to describe current-voltage (JV)-curves, as it assumes a high electrical conductivity of the charge transporting material. Here, an analytical expression for the JV-curves of organic solar cells is derived based on a previously published analytical model. This expression, bearing a similar functional dependence as the Shockley-equation, delivers a new figure of merit α to express the balance between free charge recombination and extraction in low mobility photoactive materials. This figure of merit is shown to determine critical device parameters such as the apparent series resistance and the fill factor.
KW  - Electronic and spintronic devices
KW  - Semiconductors
Y1  - 2016
U6  - https://doi.org/10.1038/srep24861
SN  - 2045-2322
VL  - 6
PB  - Nature Publishing Group
CY  - London
ER  - 
TY  - JOUR
A1  - Negrete, Jose
A1  - Pumir, Alain
A1  - Hsu, Hsin-Fang
A1  - Westendorf, Christian
A1  - Tarantola, Marco
A1  - Beta, Carsten
A1  - Bodenschatz, Eberhard
T1  - Noisy Oscillations in the Actin Cytoskeleton of Chemotactic Amoeba
JF  - Physical review letters
N2  - Biological systems with their complex biochemical networks are known to be intrinsically noisy. Here we investigate the dynamics of actin polymerization of amoeboid cells, which are close to the onset of oscillations. We show that the large phenotypic variability in the polymerization dynamics can be accurately captured by a generic nonlinear oscillator model in the presence of noise. We determine the relative role of the noise with a single dimensionless, experimentally accessible parameter, thus providing a quantitative description of the variability in a population of cells. Our approach, which rests on a generic description of a system close to a Hopf bifurcation and includes the effect of noise, can characterize the dynamics of a large class of noisy systems close to an oscillatory instability.
Y1  - 2016
U6  - https://doi.org/10.1103/PhysRevLett.117.148102
SN  - 0031-9007
SN  - 1079-7114
VL  - 117
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Nagornov, Roman
A1  - Osipoy, Grigory
A1  - Komarov, Maxim
A1  - Pikovskij, Arkadij
A1  - Shilnikov, Andrey
T1  - Mixed-mode synchronization between two inhibitory neurons with post-inhibitory rebound
JF  - Communications in nonlinear science & numerical simulation
N2  - We study an array of activity rhythms generated by a half-center oscillator (HCO), represented by a pair of reciprocally coupled neurons with post-inhibitory rebounds (PIR). Such coupling induced bursting possesses two time scales, one for fast spiking and another for slow quiescent periods, is shown to exhibit an array of synchronization properties. We discuss several HCO configurations constituted by two endogenous bursters, by tonic-spiking and quiescent neurons, as well as mixed-mode configurations composed of neurons of different type. We demonstrate that burst synchronization can be accompanied by complex, often chaotic, interactions of fast spikes within synchronized bursts. (C) 2015 Elsevier B.V. All rights reserved.
KW  - Synchronization
KW  - Hodgkin-Huxley model
KW  - Half-center oscillator
KW  - Post-inhibitory rebound
Y1  - 2016
U6  - https://doi.org/10.1016/j.cnsns.2015.11.024
SN  - 1007-5704
SN  - 1878-7274
VL  - 36
SP  - 175
EP  - 191
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Münch, Thomas
A1  - Kipfstuhl, Sepp
A1  - Freitag, Johannes
A1  - Meyer, Hanno
A1  - Laepple, Thomas
T1  - Regional climate signal vs. local noise: a two-dimensional view of water isotopes in Antarctic firn at Kohnen Station, Dronning Maud Land
JF  - Climate of the past : an interactive open access journal of the European Geosciences Union
N2  - In low-accumulation regions, the reliability of delta O-18-derived temperature signals from ice cores within the Holocene is unclear, primarily due to the small climate changes relative to the intrinsic noise of the isotopic signal. In order to learn about the representativity of single ice cores and to optimise future ice-core-based climate reconstructions, we studied the stable-water isotope composition of firn at Kohnen Station, Dronning Maud Land, Antarctica. Analysing delta O-18 in two 50m long snow trenches allowed us to create an unprecedented, two-dimensional image characterising the isotopic variations from the centimetre to the 100-metre scale. Our results show seasonal layering of the isotopic composition but also high horizontal isotopic variability caused by local stratigraphic noise. Based on the horizontal and vertical structure of the isotopic variations, we derive a statistical noise model which successfully explains the trench data. The model further allows one to determine an upper bound for the reliability of climate reconstructions conducted in our study region at seasonal to annual resolution, depending on the number and the spacing of the cores taken.
Y1  - 2016
U6  - https://doi.org/10.5194/cp-12-1565-2016
SN  - 1814-9324
SN  - 1814-9332
VL  - 12
SP  - 1565
EP  - 1581
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Mueller, Lars
A1  - Nanova, Diana
A1  - Glaser, Tobias
A1  - Beck, Sebastian
A1  - Pucci, Annemarie
A1  - Kast, Anne K.
A1  - Schroeder, Rasmus R.
A1  - Mankel, Eric
A1  - Pingel, Patrick
A1  - Neher, Dieter
A1  - Kowalsky, Wolfgang
A1  - Lovrincic, Robert
T1  - Charge-Transfer-Solvent Interaction Predefines Doping Efficiency in p-Doped P3HT Films
JF  - Chemistry of materials : a publication of the American Chemical Society
N2  - Efficient electrical doping of organic semiconductors is a necessary prerequisite for the fabrication of high performance organic electronic devices. In this work, we study p-type doping of poly(3-hexylthiophene) (P3HT) with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F(4)TCNQ) spin-cast from two different solvents. Using electron diffraction, we find strong dopant-induced pi-pi-stacking for films from the solvent chloroform, but not from chlorobenzene. This image is confirmed and expanded by the analysis of vibrational features of P3HT and polaron absorptions using optical spectroscopy. Here, a red-shifted polaron absorption is found in doped films from chloroform, caused by a higher conjugation length of the polymer backbone. These differences result in a higher conductivity of films from chloroform. We use optical spectroscopy on the corresponding blend solutions to shed light on the origin of this effect and propose a model to explain why solutions of doped P3HT reveal more aggregation of charged molecules in chlorobenzene, whereas more order is finally observed in dried films from chloroform. Our study emphasizes the importance of solvent parameters exceeding the bare solubility of pure dopant and host material for the preparation of highly conductive doped films.
Y1  - 2016
U6  - https://doi.org/10.1021/acs.chemmater.6b01629
SN  - 0897-4756
SN  - 1520-5002
VL  - 28
SP  - 4432
EP  - 4439
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Moretti, M. I.
A1  - Clementini, Gisella
A1  - Marconi, V. Ripepi M.
A1  - Rubele, S.
A1  - Cioni, Maria-Rosa L.
A1  - Muraveva, T.
A1  - Groenewegen, M. A. T.
A1  - Cross, N. J. G.
A1  - Ivanov, V. D.
A1  - Piatti, A. E.
A1  - de Grijs, Richard
T1  - The VMC survey - XX. Identification of new Cepheids in the Small Magellanic Cloud
JF  - Monthly notices of the Royal Astronomical Society
N2  - We present K-s-band light curves for 299 Cepheids in the Small Magellanic Cloud (SMC) of which 288 are new discoveries that we have identified using multi-epoch near-infrared photometry obtained by the VISTA survey of the Magellanic Clouds system (VMC). The new Cepheids have periods in the range from 0.34 to 9.1 d and cover the magnitude interval 12.9 <= currency sign < K-s > <= currency sign 17.6 mag. Our method was developed using variable stars previously identified by the optical microlensing survey OGLE. We focus on searching new Cepheids in external regions of the SMC for which complete VMC K-s-band observations are available and no comprehensive identification of different types of variable stars from other surveys exists yet.
KW  - methods: data analysis
KW  - surveys
KW  - stars: variables: Cepheids
KW  - Magellanic Clouds
Y1  - 2016
U6  - https://doi.org/10.1093/mnras/stw716
SN  - 0035-8711
SN  - 1365-2966
VL  - 459
SP  - 1687
EP  - 1697
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Moradi, N.
A1  - Zakrevskyy, Yuriy
A1  - Javadi, A.
A1  - Aksenenko, E. V.
A1  - Fainerman, V. B.
A1  - Lomadze, Nino
A1  - Santer, Svetlana
A1  - Miller, R.
T1  - Surface tension and dilation rheology of DNA solutions in mixtures with azobenzene-containing cationic surfactant
JF  - Colloids and surfaces : an international journal devoted to the principles and applications of colloid and interface science ; A, Physicochemical and engineering aspects
N2  - The surface tension and dilational surface visco-elasticity of the individual solutions of the biopolymer DNA and the azobenzene-containing cationic surfactant AzoTAB, as well as their mixtures were measured using the drop profile analysis tensiometry. The negatively charged DNA molecules form complexes with the cationic surfactant AzoTAB. Mixed DNA + AzoTAB solutions exhibit high surface activity and surface layer elasticity. Extremes in the dependence of these characteristics on the AzoTAB concentration exist within the concentration range of 3 x 10(-6)-5 x 10(-5) M. The surface tension of the mixture shows a minimum with a subsequent maximum. In the same concentration range the elasticity shows first a maximum and then a subsequent minimum. A recently developed thermodynamic model was modified to account for the dependence of the adsorption equilibrium constant of the adsorbed complex on the cationic surfactant concentration. This modified theory shows good agreement with the experimental data both for the surface tension and the elasticity values over the entire range of studied AzoTAB concentrations. (C) 2016 Elsevier B.V. All rights reserved.
KW  - Mixed adsorption layers
KW  - Polymer/surfactant interaction
KW  - Water/air interface
KW  - Thermodynamics of adsorption
KW  - Dilational rheology
KW  - Drop profile analysis tensiometry
Y1  - 2016
U6  - https://doi.org/10.1016/j.colsurfa.2016.04.021
SN  - 0927-7757
SN  - 1873-4359
VL  - 505
SP  - 186
EP  - 192
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Metzler, Ralf
A1  - Jeon, J. -H.
A1  - Cherstvy, Andrey G.
T1  - Non-Brownian diffusion in lipid membranes: Experiments and simulations
JF  - Biochimica et biophysica acta : Biomembranes
N2  - The dynamics of constituents and the surface response of cellular membranes also in connection to the binding of various particles and macromolecules to the membrane are still a matter of controversy in the membrane biophysics community, particularly with respect to crowded membranes of living biological cells. We here put into perspective recent single particle tracking experiments in the plasma membranes of living cells and supercomputing studies of lipid bilayer model membranes with and without protein crowding. Special emphasis is put on the observation of anomalous, non-Brownian diffusion of both lipid molecules and proteins embedded in the lipid bilayer. While single component, pure lipid bilayers in simulations exhibit only transient anomalous diffusion of lipid molecules on nanosecond time scales, the persistence of anomalous diffusion becomes significantly longer ranged on the addition of disorder through the addition of cholesterol or proteins and on passing of the membrane lipids to the gel phase. Concurrently, experiments demonstrate the anomalous diffusion of membrane embedded proteins up to macroscopic time scales in the minute time range. Particular emphasis will be put on the physical character of the anomalous diffusion, in particular, the occurrence of ageing observed in the experiments the effective diffusivity of the measured particles is a decreasing function of time. Moreover, we present results for the time dependent local scaling exponent of the mean squared displacement of the monitored particles. Recent results finding deviations from the commonly assumed Gaussian diffusion patterns in protein crowded membranes are reported. The properties of the displacement autocorrelation function of the lipid molecules are discussed in the light of their appropriate physical anomalous diffusion models, both for non-crowded and crowded membranes. In the last part of this review we address the upcoming field of membrane distortion by elongated membrane-binding particles. We discuss how membrane compartmentalisation and the particle-membrane binding energy may impact the dynamics and response of lipid membranes. This article is part of a Special Issue entitled: Biosimulations edited by Ilpo Vattulainen and Tomasz Rog. (C) 2016 The Authors. Published by Elsevier B.V.
KW  - Lipid bilayer
KW  - Protein crowding
KW  - Anomalous diffusion
KW  - Simulations
KW  - Stochastic modelling
KW  - Non-Gaussian
Y1  - 2016
U6  - https://doi.org/10.1016/j.bbamem.2016.01.022
SN  - 0005-2736
SN  - 0006-3002
VL  - 1858
SP  - 2451
EP  - 2467
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - GEN
A1  - Metzler, Ralf
T1  - PROTEIN PHYSICS Forever ageing
T2  - Nature physics
N2  - Single-molecule techniques have long given us insight into the motion and interactions of individual molecules. But simulations now show that the dynamics inside single proteins is not as simple as we thought — and that proteins are forever changing.
Y1  - 2016
U6  - https://doi.org/10.1038/nphys3585
SN  - 1745-2473
SN  - 1745-2481
VL  - 12
SP  - 113
EP  - 114
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Mengel, Matthias
A1  - Feldmann, Johannes
A1  - Levermann, Anders
T1  - Linear sea-level response to abrupt ocean warming of major West Antarctic ice basin
JF  - Nature climate change
N2  - Antarctica’s contribution to global sea-level rise has recently been increasing1. Whether its ice discharge will become unstable and decouple from anthropogenic forcing2,3,4 or increase linearly with the warming of the surrounding ocean is of fundamental importance5. Under unabated greenhouse-gas emissions, ocean models indicate an abrupt intrusion of warm circumpolar deep water into the cavity below West Antarctica’s Filchner–Ronne ice shelf within the next two centuries6,7. The ice basin’s retrograde bed slope would allow for an unstable ice-sheet retreat8, but the buttressing of the large ice shelf and the narrow glacier troughs tend to inhibit such instability9,10,11. It is unclear whether future ice loss will be dominated by ice instability or anthropogenic forcing. Here we show in regional and continental-scale ice-sheet simulations, which are capable of resolving unstable grounding-line retreat, that the sea-level response of the Filchner–Ronne ice basin is not dominated by ice instability and follows the strength of the forcing quasi-linearly. We find that the ice loss reduces after each pulse of projected warm water intrusion. The long-term sea-level contribution is approximately proportional to the total shelf-ice melt. Although the local instabilities might dominate the ice loss for weak oceanic warming12, we find that the upper limit of ice discharge from the region is determined by the forcing and not by the marine ice-sheet instability.
Y1  - 2016
U6  - https://doi.org/10.1038/NCLIMATE2808
SN  - 1758-678X
SN  - 1758-6798
VL  - 6
SP  - 71
EP  - +
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Mazurek, P.
A1  - Yu, L.
A1  - Gerhard, Reimund
A1  - Wirges, Werner
A1  - Skov, A. L.
T1  - Glycerol as high-permittivity liquid filler in dielectric silicone elastomers
JF  - Journal of applied polymer science
N2  - A recently reported novel class of elastomers was tested with respect to its dielectric properties. The new elastomer material is based on a commercially available poly(dimethylsiloxane) composition, which has been modified by embedding glycerol droplets into its matrix. The approach has two major advantages that make the material useful in a dielectric actuator. First, the glycerol droplets efficiently enhance the dielectric constant, which can reach astonishingly high values in the composite. Second, the liquid filler also acts as a softener that effectively decreases the elastic modulus of the composite. In combination with very low cost and easy preparation, the two property enhancements lead to an extremely attractive dielectric elastomer material. Experimental permittivity data are compared to various theoretical models that predict relative permittivity changes as a function of filler loading, and the applicability of the models is discussed. (c) 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44153.
KW  - crosslinking
KW  - dielectric properties
KW  - elastomers
KW  - sensors and actuators
Y1  - 2016
U6  - https://doi.org/10.1002/app.44153
SN  - 0021-8995
SN  - 1097-4628
VL  - 133
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - THES
A1  - Marx, Robert
T1  - A quantitative model of spatial correlations in parametric down conversion for investigating complementarity at a double slit
Y1  - 2016
ER  - 
TY  - JOUR
A1  - Martinez Gonzalez, M. J.
A1  - Pastor Yabar, A.
A1  - Lagg, A.
A1  - Asensio Ramos, A.
A1  - Collados Vera, M.
A1  - Solanki, S. K.
A1  - Balthasar, H.
A1  - Berkefeld, T.
A1  - Denker, Carsten
A1  - Doerr, H. P.
A1  - Feller, A.
A1  - Franz, M.
A1  - González Manrique, Sergio Javier
A1  - Hofmann, A.
A1  - Kneer, F.
A1  - Kuckein, Christoph
A1  - Louis, R.
A1  - von der Lühe, O.
A1  - Nicklas, H.
A1  - Orozco, D.
A1  - Rezaei, R.
A1  - Schlichenmaier, R.
A1  - Schmidt, D.
A1  - Schmidt, W.
A1  - Sigwarth, M.
A1  - Sobotka, M.
A1  - Soltau, D.
A1  - Staude, J.
A1  - Strassmeier, Klaus G.
A1  - Verma, Meetu
A1  - Waldman, T.
A1  - Volkmer, R.
T1  - Inference of magnetic fields in the very quiet Sun
JF  - Journal of geophysical research : Earth surface
N2  - Context. Over the past 20 yr, the quietest areas of the solar surface have revealed a weak but extremely dynamic magnetism occurring at small scales (<500 km), which may provide an important contribution to the dynamics and energetics of the outer layers of the atmosphere. Understanding this magnetism requires the inference of physical quantities from high-sensitivity spectro-polarimetric data with high spatio-temporal resolution. Aims. We present high-precision spectro-polarimetric data with high spatial resolution (0.4") of the very quiet Sun at 1.56 mu m obtained with the GREGOR telescope to shed some light on this complex magnetism. Methods. We used inversion techniques in two main approaches. First, we assumed that the observed profiles can be reproduced with a constant magnetic field atmosphere embedded in a field-free medium. Second, we assumed that the resolution element has a substructure with either two constant magnetic atmospheres or a single magnetic atmosphere with gradients of the physical quantities along the optical depth, both coexisting with a global stray-light component. Results. Half of our observed quiet-Sun region is better explained by magnetic substructure within the resolution element. However, we cannot distinguish whether this substructure comes from gradients of the physical parameters along the line of sight or from horizontal gradients (across the surface). In these pixels, a model with two magnetic components is preferred, and we find two distinct magnetic field populations. The population with the larger filling factor has very weak (similar to 150 G) horizontal fields similar to those obtained in previous works. We demonstrate that the field vector of this population is not constrained by the observations, given the spatial resolution and polarimetric accuracy of our data. The topology of the other component with the smaller filling factor is constrained by the observations for field strengths above 250 G: we infer hG fields with inclinations and azimuth values compatible with an isotropic distribution. The filling factors are typically below 30%. We also find that the flux of the two polarities is not balanced. From the other half of the observed quiet-Sun area similar to 50% are two-lobed Stokes V profiles, meaning that 23% of the field of view can be adequately explained with a single constant magnetic field embedded in a non-magnetic atmosphere. The magnetic field vector and filling factor are reliable inferred in only 50% based on the regular profiles. Therefore, 12% of the field of view harbour hG fields with filling factors typically below 30%. At our present spatial resolution, 70% of the pixels apparently are non-magnetised.
KW  - Sun: atmosphere
KW  - Sun: magnetic fields
KW  - techniques: polarimetric
KW  - methods: observational
Y1  - 2016
U6  - https://doi.org/10.1051/0004-6361/201628449
SN  - 1432-0746
VL  - 596
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Martin, Nicolas F.
A1  - Jungbluth, Valentin
A1  - Nidever, David L.
A1  - Bell, Eric F.
A1  - Besla, Gurtina
A1  - Blum, Robert D.
A1  - Cioni, Maria-Rosa L.
A1  - Conn, Blair C.
A1  - Kaleida, Catherine C.
A1  - Gallart, Carme
A1  - Jin, Shoko
A1  - Majewski, Steven R.
A1  - Martinez-Delgado, David
A1  - Monachesi, Antonela
A1  - Munoz, Ricardo R.
A1  - Noel, Noelia E. D.
A1  - Olsen, Knut
A1  - Stringfellow, Guy S.
A1  - van der Marel, Roeland P.
A1  - Vivas, A. Katherina
A1  - Walker, Alistair R.
A1  - Zaritsky, Dennis
T1  - SMASH 1: A VERY FAINT GLOBULAR CLUSTER DISRUPTING IN THE OUTER REACHES OF THE LMC?
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
KW  - globular clusters: individual: (SMASH 1)
KW  - Local Group
KW  - Magellanic Clouds
Y1  - 2016
U6  - https://doi.org/10.3847/2041-8205/830/1/L10
SN  - 2041-8205
SN  - 2041-8213
VL  - 830
SP  - 92
EP  - 98
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  -