Ulrich, Stephan

[["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Physical Review. E"],["dc.bibliographiccitation.volume","74"],["dc.contributor.author","Schröter, Matthias"],["dc.contributor.author","Ulrich, Stephan"],["dc.contributor.author","Kreft, Jennifer"],["dc.contributor.author","Swift, Jack B."],["dc.contributor.author","Swinney, Harry L."],["dc.date.accessioned","2022-06-08T07:59:37Z"],["dc.date.available","2022-06-08T07:59:37Z"],["dc.date.issued","2006"],["dc.identifier.doi","10.1103/PhysRevE.74.011307"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/110809"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-575"],["dc.relation.eissn","1550-2376"],["dc.relation.issn","1539-3755"],["dc.title","Mechanisms in the size segregation of a binary granular mixture"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","042301"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","PHYSICAL REVIEW E"],["dc.bibliographiccitation.volume","76"],["dc.contributor.author","Ulrich, Stephan"],["dc.contributor.author","Schroeter, Matthias"],["dc.contributor.author","Swinney, Harry L."],["dc.date.accessioned","2018-11-07T10:58:23Z"],["dc.date.available","2018-11-07T10:58:23Z"],["dc.date.issued","2007"],["dc.description.abstract","Vertical shaking of a mixture of small and large beads can lead to segregation where the large beads either accumulate at the top of the sample, the so-called Brazil nut effect (BNE), or at the bottom, the reverse Brazil nut effect (RBNE). Here we demonstrate experimentally a sharp transition from the RBNE to the BNE when the particle coefficient of friction increases due to aging of the particles. This result can be explained by the two competing mechanisms of buoyancy and sidewall-driven convection, where the latter is assumed to grow in strength with increasing friction."],["dc.identifier.doi","10.1103/PhysRevE.76.042301"],["dc.identifier.isi","000250621900123"],["dc.identifier.pmid","17995042"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/50465"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Physical Soc"],["dc.relation.issn","1539-3755"],["dc.title","Influence of friction on granular segregation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","166001"],["dc.bibliographiccitation.issue","16"],["dc.bibliographiccitation.journal","Physical Review Letters"],["dc.bibliographiccitation.volume","109"],["dc.contributor.author","Ulrich, Stephan"],["dc.contributor.author","Zippelius, Annette"],["dc.date.accessioned","2018-11-07T09:04:32Z"],["dc.date.available","2018-11-07T09:04:32Z"],["dc.date.issued","2012"],["dc.description.abstract","A freely falling stream of weakly cohesive granular particles is modeled and analyzed with the help of event driven simulations and continuum hydrodynamics. The former show a breakup of the stream into droplets, whose size is measured as a function of cohesive energy. Extensional flow is an exact solution of the one-dimensional Navier-Stokes equation, corresponding to a strain rate, decaying like t(-1) from its initial value, (gamma)over dot(0). Expanding around this basic state, we show that the flow is stable for short times, (gamma)over dot(0)t << 1, whereas for long times, (gamma)over dot(0)t >> 1, perturbations of all wavelengths grow. The growth rate of a given wavelength depends on the instant of time when the fluctuation occurs, so that the observable patterns can vary considerably."],["dc.identifier.doi","10.1103/PhysRevLett.109.166001"],["dc.identifier.isi","000310004300007"],["dc.identifier.pmid","23215093"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/25128"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Physical Soc"],["dc.relation.issn","0031-9007"],["dc.title","Stability of Freely Falling Granular Streams"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","115011"],["dc.bibliographiccitation.journal","New Journal of Physics"],["dc.bibliographiccitation.volume","14"],["dc.contributor.author","Benetatos, Panayotis"],["dc.contributor.author","Ulrich, Stephan"],["dc.contributor.author","Zippelius, Annette"],["dc.date.accessioned","2018-11-07T09:03:17Z"],["dc.date.available","2018-11-07T09:03:17Z"],["dc.date.issued","2012"],["dc.description.abstract","Cross-linked polymer networks with orientational order constitute a wide class of soft materials and are relevant to biological systems (e. g., F-actin bundles). We analytically study the nonlinear force-extension relation of an array of parallel-aligned, strongly stretched semiflexible polymers with random cross-links. In the strong stretching limit, the effect of the cross-links is purely entropic, independent of the bending rigidity of the chains. Cross-links enhance the differential stretching stiffness of the bundle. For hard cross-links, the cross-link contribution to the force-extension relation scales inversely proportional to the force. Its dependence on the cross-link density, close to the gelation transition, is the same as that of the shear modulus. The qualitative behaviour is captured by a toy model of two chains with a single cross-link in the middle."],["dc.description.sponsorship","DFG [SFB 937]; EPSRC via the University of Cambridge TCM Programme Grant"],["dc.identifier.doi","10.1088/1367-2630/14/11/115011"],["dc.identifier.fs","591080"],["dc.identifier.isi","000311581600002"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10186"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/24877"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","1367-2630"],["dc.relation.orgunit","Fakultät für Physik"],["dc.rights","CC BY 3.0"],["dc.title","Force-extension relation of cross-linked anisotropic polymer networks"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","14"],["dc.bibliographiccitation.journal","Physical Review Letters"],["dc.bibliographiccitation.lastpage","4"],["dc.bibliographiccitation.volume","102"],["dc.contributor.author","Ulrich, Stephan"],["dc.contributor.author","Aspelmeier, Timo"],["dc.contributor.author","Roeller, Klaus"],["dc.contributor.author","Fingerle, Axel"],["dc.contributor.author","Herminghaus, Stephan"],["dc.contributor.author","Zippelius, Annette"],["dc.date.accessioned","2021-06-01T10:47:05Z"],["dc.date.available","2021-06-01T10:47:05Z"],["dc.date.issued","2009"],["dc.description.abstract","Wet granular materials are characterized by a defined bond energy in their particle interaction such that breaking a bond implies an irreversible loss of a fixed amount of energy. Associated with the bond energy is a nonequilibrium transition, setting in as the granular temperature falls below the bond energy. The subsequent aggregation of particles into clusters is shown to be a self-similar growth process with a cluster size distribution that obeys scaling. In the early phase of aggregation the clusters are fractals with Df=2, for later times we observe gelation. We use simple scaling arguments to derive the temperature decay in the early and late stages of cooling and verify our results with event-driven simulations."],["dc.identifier.doi","10.1103/PhysRevLett.102.148002"],["dc.identifier.gro","3146215"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/85479"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-425"],["dc.notes.status","final"],["dc.relation.eissn","1079-7114"],["dc.relation.issn","0031-9007"],["dc.title","Cooling and Aggregation in Wet Granulates"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Physical Review Letters"],["dc.bibliographiccitation.volume","111"],["dc.contributor.author","Neudecker, Max"],["dc.contributor.author","Ulrich, Stephan"],["dc.contributor.author","Herminghaus, Stephan"],["dc.contributor.author","Schröter, Matthias"],["dc.date.accessioned","2021-06-01T10:47:06Z"],["dc.date.available","2021-06-01T10:47:06Z"],["dc.date.issued","2013"],["dc.description.abstract","We prepare packings of frictional tetrahedra with volume fractions ϕ ranging from 0.469 to 0.622 using three different experimental protocols under isobaric conditions. Analysis via x-ray microtomography reveals that the contact number Z grows with ϕ, but does depend on the preparation protocol. While there exist four different types of contacts in tetrahedra packings, our analysis shows that the edge-to-face contacts contribute about 50% of the total increase in Z. The number of constraints per particle C increases also with ϕ and even the loosest packings are strongly hyperstatic, i.e., mechanically overdetermined with C approximately twice the degrees of freedom each particle possesses."],["dc.identifier.doi","10.1103/PhysRevLett.111.028001"],["dc.identifier.gro","3146169"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/85482"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-425"],["dc.notes.status","public"],["dc.relation.eissn","1079-7114"],["dc.relation.issn","0031-9007"],["dc.title","Jammed Frictional Tetrahedra are Hyperstatic"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","021802"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Physical Review. E"],["dc.bibliographiccitation.volume","81"],["dc.contributor.author","Ulrich, Stephan"],["dc.contributor.author","Zippelius, Annette"],["dc.contributor.author","Benetatos, Panayotis"],["dc.date.accessioned","2018-11-07T08:46:34Z"],["dc.date.available","2018-11-07T08:46:34Z"],["dc.date.issued","2010"],["dc.description.abstract","We explore the effect of random permanent cross-links on a system of directed polymers confined between two planes with their end points free to slide on them. We treat the cross-links as quenched disorder and we use a semimicroscopic replica field theory to study the structure and elasticity of this system. Upon increasing the cross-link density, we get a continuous gelation transition signaled by the emergence of a finite in-plane localization length. The distribution of localization length turns out to depend on the height along the preferred direction of the directed polymers. The gelation transition also gives rise to a finite in-plane shear modulus which we calculate and turns out to be universal, i.e., independent of the energy and length scales of the polymers and the cross-links. Using a symmetry argument, we show that cross-links of negligible extent along the preferred axis of the directed polymers do not cause any renormalization to the tilt modulus of the uncross-linked system."],["dc.description.sponsorship","DFG [SFB 602]; University of Cambridge TCM Programme"],["dc.identifier.doi","10.1103/PhysRevE.81.021802"],["dc.identifier.isi","000275053700074"],["dc.identifier.pmid","20365585"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/20724"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Physical Soc"],["dc.relation.issn","1539-3755"],["dc.title","Random networks of cross-linked directed polymers"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","031306"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Physical Review. E"],["dc.bibliographiccitation.volume","80"],["dc.contributor.author","Ulrich, Stephan"],["dc.contributor.author","Aspelmeier, Timo"],["dc.contributor.author","Zippelius, Annette"],["dc.contributor.author","Roeller, Klaus"],["dc.contributor.author","Fingerle, Axel"],["dc.contributor.author","Herminghaus, Stephan"],["dc.date.accessioned","2018-11-07T11:25:24Z"],["dc.date.available","2018-11-07T11:25:24Z"],["dc.date.issued","2009"],["dc.description.abstract","We investigate a gas of wet granular particles covered by a thin liquid film. The dynamic evolution is governed by two-particle interactions, which are mainly due to interfacial forces in contrast to dry granular gases. When two wet grains collide, a capillary bridge is formed and stays intact up to a certain distance of withdrawal when the bridge ruptures, dissipating a fixed amount of energy. A freely cooling system is shown to undergo a nonequilibrium dynamic phase transition from a state with mainly single particles and fast cooling to a state with growing aggregates such that bridge rupture becomes a rare event and cooling is slow. In the early stage of cluster growth, aggregation is a self-similar process with a fractal dimension of the aggregates approximately equal to D(f) approximate to 2. At later times, a percolating cluster is observed which ultimately absorbs all the particles. The final cluster is compact on large length scales, but fractal with D(f) approximate to 2 on small length scales."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft (DFG) [SFB 602/B6]"],["dc.identifier.doi","10.1103/PhysRevE.80.031306"],["dc.identifier.isi","000270383400069"],["dc.identifier.pmid","19905109"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/56613"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Physical Soc"],["dc.relation.issn","1539-3755"],["dc.title","Dilute wet granular particles: Nonequilibrium dynamics and structure formation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]