56 research outputs found

    Imbibition in Disordered Media

    Full text link
    The physics of liquids in porous media gives rise to many interesting phenomena, including imbibition where a viscous fluid displaces a less viscous one. Here we discuss the theoretical and experimental progress made in recent years in this field. The emphasis is on an interfacial description, akin to the focus of a statistical physics approach. Coarse-grained equations of motion have been recently presented in the literature. These contain terms that take into account the pertinent features of imbibition: non-locality and the quenched noise that arises from the random environment, fluctuations of the fluid flow and capillary forces. The theoretical progress has highlighted the presence of intrinsic length-scales that invalidate scale invariance often assumed to be present in kinetic roughening processes such as that of a two-phase boundary in liquid penetration. Another important fact is that the macroscopic fluid flow, the kinetic roughening properties, and the effective noise in the problem are all coupled. Many possible deviations from simple scaling behaviour exist, and we outline the experimental evidence. Finally, prospects for further work, both theoretical and experimental, are discussed.Comment: Review article, to appear in Advances in Physics, 53 pages LaTe

    Action observation can prime visual object recognition

    Get PDF
    Observing an action activates action representations in the motor system. Moreover, the representations of manipulable objects are closely linked to the motor systems at a functional and neuroanatomical level. Here, we investigated whether action observation can facilitate object recognition using an action priming paradigm. As prime stimuli we presented short video movies showing hands performing an action in interaction with an object (where the object itself was always removed from the video). The prime movie was followed by a (briefly presented) target object affording motor interactions that are either similar (congruent condition) or dissimilar (incongruent condition) to the prime action. Participants had to decide whether an object name shown after the target picture corresponds with the picture or not (picture–word matching task). We found superior accuracy for prime–target pairs with congruent as compared to incongruent actions across two experiments. Thus, action observation can facilitate recognition of a manipulable object typically involving a similar action. This action priming effect supports the notion that action representations play a functional role in object recognition

    Measuring socio-demographic differences in volunteers with a value-based index: illustration in a mega event

    Get PDF
    The phenomenon of volunteering can be analysed as a consumer experience through the concept of value as a trade-off between benefits and costs. In event volunteering, both the expected value (pre-experienced) and the perceived value (post-experienced) of volunteering can be assessed. With this purpose, an online quantitative survey is conducted with a sample of 711 volunteers in a religious mega event, with questions related to five dimensions of their experience: efficiency, social value, play, spirituality and time spent. These five scales, properly tested are used for building a multidimensional index of both the expected and perceived value of the volunteer experience. ANOVAs test show significant differences on the index in both moments upon the socio-demographic profiles: negative expectations/experience balance by age, contrasted results by sex, and more experienced volunteers being more critical with the value experienced. Implications for event managers are proposed, in line with the motivation of volunteers

    On the Importance of Complaint Handling Design : A Multi-Level Analysis of the Impact in Specific Complaint Situations

    Full text link
    Given the large investments required for high-quality complaint handling design, managers need practical guidance in understanding its actual importance for their particular company. However, while prior research emphasizes the general relevance of complaint handling design, it fails to provide a more differentiated perspective on this interesting issue. This study, which is based on an integrative multi-level framework and a dyadic dataset, addresses this important gap in research. Results indicate that the impact of a company’s complaint handling design varies significantly depending on the characteristics of the complaining customers with which the firm has to deal. Further, this paper shows that, contingent on these characteristics, a company’s complaint handling design can shape complainants’ fairness perceptions either considerably or only slightly. Overall, findings suggest that companies should apply an adaptive approach to complaint handling to avoid misallocation of attention, energy, and resources

    Manipulable Objects Facilitate Cross-Modal Integration in Peripersonal Space

    Get PDF
    Previous studies have shown that tool use often modifies one's peripersonal space – i.e. the space directly surrounding our body. Given our profound experience with manipulable objects (e.g. a toothbrush, a comb or a teapot) in the present study we hypothesized that the observation of pictures representing manipulable objects would result in a remapping of peripersonal space as well. Subjects were required to report the location of vibrotactile stimuli delivered to the right hand, while ignoring visual distractors superimposed on pictures representing everyday objects. Pictures could represent objects that were of high manipulability (e.g. a cell phone), medium manipulability (e.g. a soap dispenser) and low manipulability (e.g. a computer screen). In the first experiment, when subjects attended to the action associated with the objects, a strong cross-modal congruency effect (CCE) was observed for pictures representing medium and high manipulability objects, reflected in faster reaction times if the vibrotactile stimulus and the visual distractor were in the same location, whereas no CCE was observed for low manipulability objects. This finding was replicated in a second experiment in which subjects attended to the visual properties of the objects. These findings suggest that the observation of manipulable objects facilitates cross-modal integration in peripersonal space

    Megascopic Quantum Phenomena. A Critical Study of Physical Interpretations

    Full text link
    A megascopic revalidation is offered providing responses and resolutions of current inconsistencies and existing contradictions in present-day quantum theory. As the core of this study we present an independent proof of the Goldstone theorem for a quantum field formulation of molecules and solids. Along with phonons two types of new quasiparticles appear: rotons and translons. In full analogy with Lorentz covariance, combining space and time coordinates, a new covariance is necessary, binding together the internal and external degrees of freedom, without explicitly separating the centre-of-mass, which normally applies in both classical and quantum formulations. The generally accepted view regarding the lack of a simple correspondence between the Goldstone modes and broken symmetries, has significant consequences: an ambiguous BCS theory as well as a subsequent Higgs mechanism. The application of the archetype of the classical spontaneous symmetry breaking, i.e. the Mexican hat, as compared to standard quantum relations, i.e. the Jahn-Teller effect, superconductivity or the Higgs mechanism, becomes a disparity. In short, symmetry broken states have a microscopic causal origin, but transitions between them have a teleological component. The different treatments of the problem of the centre of gravity in quantum mechanics and in field theories imply a second type of Bohr complementarity on the many-body level opening the door for megascopic representations of all basic microscopic quantum axioms with further readings for teleonomic megascopic quantum phenomena, which have no microscopic rationale: isomeric transitions, Jahn-Teller effect, chemical reactions, Einstein-de Haas effect, superconductivity-superfluidity, and brittle fracture.Comment: 117 pages, 17 sections, final revised version from 20 May 2019 but uploaded after the DOI was know
    corecore