SMSlingshot a shared encounter in urban space

Interaction design is increasingly situated beyond the desktop and demands new approaches, if it is made for Urban Space. Public and semi-public spaces add new challenges in terms of interaction theory, technology and sociology. SMSlingshot is an interactive unban installation (also named a Shared Encounter) and research vehicle that helps to explore these new challenges

Red blood cells and other non-spherical capsules in shear flow: oscillatory dynamics and the tank-treading-to-tumbling transition

We consider the motion of red blood cells and other non-spherical microcapsules dilutely suspended in a simple shear flow. Our analysis indicates that depending on the viscosity, membrane elasticity, geometry and shear rate, the particle exhibits either tumbling, tank-treading of the membrane about the viscous interior with periodic oscillations of the orientation angle, or intermittent behavior in which the two modes occur alternately. For red blood cells, we compute the complete phase diagram and identify a novel tank-treading-to-tumbling transition at low shear rates. Observations of such motions coupled with our theoretical framework may provide a sensitive means of assessing capsule properties.Comment: 11 pages, 4 figure

Large-scale calculations of supernova neutrino-induced reactions in Z=8-82 target nuclei

Background: In the environment of high neutrino-fluxes provided in core-collapse supernovae or neutron star mergers, neutrino-induced reactions with nuclei contribute to the nucleosynthesis processes. A number of terrestrial neutrino detectors are based on inelastic neutrino-nucleus scattering and modeling of the respective cross sections allow predictions of the expected detector reaction rates. Purpose: To provide a self-consistent microscopic description of neutrino-nucleus cross sections involving a large pool of Z = 8 - 82 nuclei for the implementation in models of nucleosynthesis and neutrino detector simulations. Methods: Self-consistent theory framework based on relativistic nuclear energy density functional is employed to determine the nuclear structure of the initial state and relevant transitions to excited states induced by neutrinos. The weak neutrino-nucleus interaction is employed in the current-current form and a complete set of transition operators is taken into account. Results: We perform large-scale calculations of charged-current neutrino-nucleus cross sections, including those averaged over supernova neutrino fluxes, for the set of even-even target nuclei from oxygen toward lead (Z = 8 - 82), spanning N = 8 - 182 (OPb pool). The model calculations include allowed and forbidden transitions up to J = 5 multipoles. Conclusions: The present analysis shows that the self-consistent calculations result in considerable differences in comparison to previously reported cross sections, and for a large number of target nuclei the cross sections are enhanced. Revision in modeling r-process nucleosynthesis based on a self-consistent description of neutrino-induced reactions would allow an updated insight into the origin of elements in the Universe and it would provide the estimate of uncertainties in the calculated element abundance patterns.Comment: 25 pages, 12 figures, submitted to Physical Review

Mechanistic Links Between the Sedimentary Redox Cycle and Marine Acid-Base Chemistry

The redox state of Earth's surface is controlled on geological timescales by the flow of electrons through the sedimentary rock cycle, mediated largely by the weathering and burial of C‐S‐Fe phases. These processes buffer atmospheric pO₂. At the same time, CO₂ influxes and carbonate burial control seawater acid‐base chemistry and climate over long timescales via the carbonate‐silicate cycle. However, these two systems are mechanistically linked and impact each other via charge balance in the hydrosphere. Here, we use a low‐order Earth system model to interrogate a subset of these connections, with a focus on changes that occur during perturbations to electron flow through the sedimentary rock cycle. We show that the net oxidation or reduction of the Earth's surface can play an important role in controlling acid‐base processes in the oceans and thus climate, and suggest that these links should be more fully integrated into interpretive frameworks aimed at understanding Earth system evolution throughout Precambrian and Phanerozoic time

Lipschitz-continuity of the integrated density of states for Gaussian random potentials

The integrated density of states of a Schroedinger operator with random potential given by a homogeneous Gaussian field whose covariance function is continuous, compactly supported and has positive mean, is locally uniformly Lipschitz-continuous. This is proven using a Wegner estimate

Early egg traits in Cancer setosus (Decapoda, Brachyura): effects of temperature and female size

Previous study on Cancer setosus (Molina, 1782) had shown that latitudinal changes in temperature control the number of annual egg masses. This study focused on the effects of pre-oviposition temperature and female size on egg-traits in C. setosus from Northern (Antofagasta 23ºS) and Central-Southern (Puerto Montt 41ºS) Chile. Blastula eggs produced in nature ranged in dry mass (DM) from 9.1 to 15.1 µg, in carbon (C) from 4.8 to 8.4 µg, in nitrogen (N) from 1.0 to 1.6 µg, in C:N ratio between 4.7 and 5.4, and in volume (V) between 152 and 276 mm3 x 10-4 per female. Blastula eggs from females caught early in the reproductive season in Puerto Montt (09/2006) were significantly higher in DM, C, N, and V than those of females caught two months later (11/2006), reflecting a seasonal increase in water temperature. In Puerto Montt “early” and “late” season blastula eggs were about 32% and 20% higher in DM, C, N, and V as eggs from Antofagasta, respectively. Subsequent egg masses produced in captivity in Puerto Montt followed this pattern of smaller eggs with lower DM, C, and N content at higher pre-oviposition temperatures. In Antofagasta no significant difference in DM, C, N and V between eggs produced in nature and subsequent eggs produced in captivity was found and all egg traits were significantly positively affected by maternal size. Reproductive plasticity in C. setosus helps explaining the species wide latitudinal distribution range

Quantum sine-Gordon dynamics on analogue curved spacetime in a weakly imperfect scalar Bose gas

Using the coherent state functional integral expression of the partition function, we show that the sine-Gordon model on an analogue curved spacetime arises as the effective quantum field theory for phase fluctuations of a weakly imperfect Bose gas on an incompressible background superfluid flow when these fluctuations are restricted to a subspace of the single-particle Hilbert space. We consider bipartitions of the single-particle Hilbert space relevant to experiments on ultracold bosonic atomic or molecular gases, including, e.g., restriction to high- or low-energy sectors of the dynamics and spatial bipartition corresponding to tunnel-coupled planar Bose gases. By assuming full unitary quantum control in the low-energy subspace of a trapped gas, we show that (1) appropriately tuning the particle number statistics of the lowest-energy mode partially decouples the low- and high-energy sectors, allowing any low-energy single-particle wave function to define a background for sine-Gordon dynamics on curved spacetime and (2) macroscopic occupation of a quantum superposition of two states of the lowest two modes produces an analogue curved spacetime depending on two background flows, with respective weights continuously dependent on the corresponding weights of the superposed quantum states.Comment: 12 pages, 1 figur