How micropatterns and air pressure affect splashing on surfaces

We experimentally investigate the splashing mechanism of a millimeter-sized ethanol drop impinging on a structured solid surface, comprised of micro-pillars, through side-view and top-view high speed imaging. By increasing the impact velocity we can tune the impact outcome from a gentle deposition to a violent splash, at which tiny droplets are emitted as the liquid sheet spreads laterally. We measure the splashing threshold for different micropatterns and find that the arrangement of the pillars significantly affects the splashing outcome. In particular, directional splashing in direction in which air flow through pattern is possible. Our top-view observations of impact dynamics reveal that an trapped air is responsible for the splashing. Indeed by lowering the pressure of the surrounding air we show that we can suppress the splashing in the explored parameter regime.Comment: 7 pages, 9 figure

Monte Carlo simulations of ordering in ferromagnetic-antiferromagnetic bilayers

Monte Carlo simulations have been used to study phase transitions on coupled anisotropic ferro/antiferromagnetic (FM/AFM) films of classical Heisenberg spins. We consider films of different thicknesses, with fully compensated exchange across the FM/AFM interface. We find indications of a phase transition on each film, occuring at different temperatures. It appears that both transition temperatures depend on the film thickness.Comment: Revtex, 4 pages, 4 figure

Dynamical Properties of a Growing Surface on a Random Substrate

The dynamics of the discrete Gaussian model for the surface of a crystal deposited on a disordered substrate is investigated by Monte Carlo simulations. The mobility of the growing surface was studied as a function of a small driving force $F$ and temperature $T$. A continuous transition is found from high-temperature phase characterized by linear response to a low-temperature phase with nonlinear, temperature dependent response. In the simulated regime of driving force the numerical results are in general agreement with recent dynamic renormalization group predictions.Comment: 10 pages, latex, 3 figures, to appear in Phys. Rev. E (RC

Memory probes:Exploring retrospective user experience through traces of use on cherished objects

Our daily interactions with objects can not only leave traces of use on the objects but also leave memories in our minds. These human traces on objects are potential cues that can trigger our autobiographical memories and connect us to social networks. The first aim of this paper is to demonstrate what might be a suitable method of inquiry into the way materials can enrich dialogues about remembered experiences derived from human traces left on cherished possessions. The second aim is to investigate how the accumulation of human traces on objects influences people’s remembering and usage. The design of our research artifacts, Memory Probes, was situated in relation to three spectra of paired values: (1) the familiarity and strangeness of tool use, (2) the definiteness and ambiguity of data capture, and (3) the objective and subjective reality of interpretation. Our field study revealed a transactive nature between traces of interaction with possessions and memories in the owners’ minds. It also informed us of how gradual and curiosity-driven understanding could become a methodological nuance when we are empathetically engaged in a collaborative way of knowing with other participants. To conclude, several implications for designing products that can participate in our everyday reminiscing and meaning-making are proposed

Designing memory probes to inform dialogue

© 2017 ACM. To investigate the phenomenon that occurs during interactions between used objects and autobiographical memories, which are both ever-changing and imbedded with personal significance, an adapted probing method capable of managing these complex qualities is needed. This pictorial is our attempt to find a nuanced indication of how probes could go beyond common usage to facilitate complex felt experience, and how probes can be used in less prescriptive ways to instead promote reminiscent dialogues that are rich and open to interpretation for both participants and researchers. It illustrates our exploration into potential Memory Probes and how this might be done that reflects the value we see in creating restrictions or limitations in technologymediated interactions to encourage active participation by users in social acts such as memory creation and remembrance

Electromagnetic radiative corrections in parity-violating electron-proton scattering

QED radiative corrections have been calculated for leptonic and hadronic variables in parity-violating elastic ep scattering. For the first time, the calculation of the asymmetry in the elastic radiative tail is performed without the peaking-approximation assumption in hadronic variables configuration. A comparison with the PV-A4 data validates our approach. This method has been also used to evaluate the radiative corrections to the parity-violating asymmetry measured in the G0 experiment. The results obtained are here presented.Comment: 12 pages, 11 figure