165 research outputs found

    Hydrodynamic coupling and rotational mobilities near planar elastic membranes

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    We study theoretically and numerically the coupling and rotational hydrodynamic interactions between spherical particles near a planar elastic membrane that exhibits resistance towards shear and bending. Using a combination of the multipole expansion and Faxen's theorems, we express the frequency-dependent hydrodynamic mobility functions as a power series of the ratio of the particle radius to the distance from the membrane for the self mobilities, and as a power series of the ratio of the radius to the interparticle distance for the pair mobilities. In the quasi-steady limit of zero frequency, we find that the shear- and bending-related contributions to the particle mobilities may have additive or suppressive effects depending on the membrane properties in addition to the geometric configuration of the interacting particles relative to the confining membrane. To elucidate the effect and role of the change of sign observed in the particle self and pair mobilities, we consider an example involving a torque-free doublet of counterrotating particles near an elastic membrane. We find that the induced rotation rate of the doublet around its center of mass may differ in magnitude and direction depending on the membrane shear and bending properties. Near a membrane of only energetic resistance toward shear deformation, such as that of a certain type of elastic capsules, the doublet undergoes rotation of the same sense as observed near a no-slip wall. Near a membrane of only energetic resistance toward bending, such as that of a fluid vesicle, we find a reversed sense of rotation. Our analytical predictions are supplemented and compared with fully resolved boundary integral simulations where a very good agreement is obtained over the whole range of applied frequencies.Comment: 14 pages, 7 figures. Revised manuscript resubmitted to J. Chem. Phy

    Nanoproteomic analysis of ischemia-dependent changes in signaling protein phosphorylation in colorectal normal and cancer tissue

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    Additional file 1: Table S1. Clinical data for the 20 patients analyzed in the study. Presents patient clinical data including tumor stage and grade

    An in-flight plasma diagnostic package for spacecraft with electric propulsion

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    The plasma diagnostics presented in this article target the plasma surrounding a spacecraft that is created by the electric thruster and its surface modifying effects. The diagnostic package includes a retarding potential analyzer, a plane Langmuir probe, and an erosion sensor. The paper describes the instrument as well as suitable test environments for mimicking the effects expected in space and shows test results. The system is to fly for the first time on the Heinrich Hertz satellite, which is scheduled to be launched in 2023. The spacecraft will be equipped with a pair of Highly Efficient Multistage Plasma Thrusters (HEMPT) and a pair of Hall thrusters for redundancy

    Exotic fluids and crystals of soft polymeric colloids

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    We discuss recent developments and present new findings in the colloidal description of soft polymeric macromolecular aggregates. For various macromolecular architectures, such as linear chains, star polymers, dendrimers and polyelectrolyte stars, the effective interactions between suitably chosen coordinates are shown to be ultrasoft, i.e., they either remain finite or diverge very slowly at zero separation. As a consequence, the fluid phases have unusual characteristics, including anomalous pair correlations and mean-field like thermodynamic behaviour. The solid phases can exhibit exotic, strongly anisotropic as well as open crystal structures. For example, the diamond and the A15-phase are shown to be stable at sufficiently high concentrations. Reentrant melting and clustering transitions are additional features displayed by such systems, resulting in phase diagrams with a very rich topology. We emphasise that many of these effects are fundamentally different from the usual archetypal hard sphere paradigm. Instead, we propose that these fluids fall into the class of mean-field fluids.Comment: 22 pages, uses iopart.cls and iopart10.clo; submitted to Journal of Physics Condensed Matter, special issue in honour of professor Peter Puse

    Gelingendes Leben - Krise als Chance für Person & Gesellschaft. Band II

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    • Peter Antes, Rel.wiss. • Petra Bahr, Theol. / Journ. • Matthias Beck Med./JS, AT • Gottfried Biewer, Bildungswiss., AT • Aladin El-Mafaalani, Pol.wiss.• Johannes Eurich, Diak.wiss. • Mario Feigel, Med. CH • Heike Gramkow, Manag.Dir. • Heinrich Greving, Heilpäd. • Udo Hahn, Theol.• Maria-C. Hallwachs, Stud., Beratg. schon betroffen • Walter Hirche, Min. a.D./Präs. Dt. UNESCO • Wolfgang Jantzen †, Soz. • Jochen-C. Kaiser, Hist. • Karl-J. Kemmelmeyer, Präs. Musikrat • Hermes Kick, Med.-Ethik • Waldemar Kippes Redemptorist JN • Ferdinand Klein, SoPäd., SK • Berthold Krüger, bpb • Christian Larsen, Arzt, CH • Ulrich Lilie Präs. Diak.W • Christian Lindmeier, SoPäd., DGfE • Ralf Meister, Bischof • Bertolt Meyer, Org.- u. Wirtschaftspsych, schon betroffen, CH • Peter Neher, Präs. Caritas • Ekkehard Nuissl, Dir. Dt. Inst. EB, DIE • Ulrich Pohl, Vorst. Bethel • Hartmann Römer, Physiker • David Roth, Lt. Hospiz • Hartmut Schlegel SoPäd. • Joachim Schoss, Unternehmer, schon betroffen, CH • Walter Surböck Med., AT• Karl-H. Steinmetz, Trad. Europ. Med., AT • Rudolf Tippelt, Bildg. Forschg. • Inge Wasserberg, Inklu.Beratg. • Walter Thirring †, Phys. CERN, C

    The neutron and its role in cosmology and particle physics

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    Experiments with cold and ultracold neutrons have reached a level of precision such that problems far beyond the scale of the present Standard Model of particle physics become accessible to experimental investigation. Due to the close links between particle physics and cosmology, these studies also permit a deep look into the very first instances of our universe. First addressed in this article, both in theory and experiment, is the problem of baryogenesis ... The question how baryogenesis could have happened is open to experimental tests, and it turns out that this problem can be curbed by the very stringent limits on an electric dipole moment of the neutron, a quantity that also has deep implications for particle physics. Then we discuss the recent spectacular observation of neutron quantization in the earth's gravitational field and of resonance transitions between such gravitational energy states. These measurements, together with new evaluations of neutron scattering data, set new constraints on deviations from Newton's gravitational law at the picometer scale. Such deviations are predicted in modern theories with extra-dimensions that propose unification of the Planck scale with the scale of the Standard Model ... Another main topic is the weak-interaction parameters in various fields of physics and astrophysics that must all be derived from measured neutron decay data. Up to now, about 10 different neutron decay observables have been measured, much more than needed in the electroweak Standard Model. This allows various precise tests for new physics beyond the Standard Model, competing with or surpassing similar tests at high-energy. The review ends with a discussion of neutron and nuclear data required in the synthesis of the elements during the "first three minutes" and later on in stellar nucleosynthesis.Comment: 91 pages, 30 figures, accepted by Reviews of Modern Physic
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