Vibration-induced climbing of drops

We report an experimental study of liquid drops moving against gravity, when placed on a vertically vibrating inclined plate, which is partially wetted by the drop. The frequency of vibrations ranges from 30 to 200 Hz, and, above a threshold in vibration acceleration, drops experience an upward motion. We attribute this surprising motion to the deformations of the drop, as a consequence of an up or down symmetry breaking induced by the presence of the substrate. We relate the direction of motion to contact angle measurements. This phenomenon can be used to move a drop along an arbitrary path in a plane, without special surface treatments or localized forcing.Comment: 4 pages, 7 figure

Characteristic Angles in the Wetting of an Angular Region: Deposit Growth

As was shown in an earlier paper [1], solids dispersed in a drying drop migrate to the (pinned) contact line. This migration is caused by outward flows driven by the loss of the solvent due to evaporation and by geometrical constraint that the drop maintains an equilibrium surface shape with a fixed boundary. Here, in continuation of our earlier paper [2], we theoretically investigate the evaporation rate, the flow field and the rate of growth of the deposit patterns in a drop over an angular sector on a plane substrate. Asymptotic power laws near the vertex (as distance to the vertex goes to zero) are obtained. A hydrodynamic model of fluid flow near the singularity of the vertex is developed and the velocity field is obtained. The rate of the deposit growth near the contact line is found in two time regimes. The deposited mass falls off as a weak power Gamma of distance close to the vertex and as a stronger power Beta of distance further from the vertex. The power Gamma depends only slightly on the opening angle Alpha and stays between roughly -1/3 and 0. The power Beta varies from -1 to 0 as the opening angle increases from 0 to 180 degrees. At a given distance from the vertex, the deposited mass grows faster and faster with time, with the greatest increase in the growth rate occurring at the early stages of the drying process.Comment: v1: 36 pages, 21 figures, LaTeX; submitted to Physical Review E; v2: minor additions to Abstract and Introductio

The continuing saga of patents and non-invasive prenatal testing

This is the final version. Available on open access from Wiley via the DOI in this recordObjective: This paper examines the IP landscape for NIPT in three key regions: USA; Europe, with particular focus on the UK, and Australia. Method: We explore the patent law issues against the commercial and healthcare environment in these regions, and consider the implications for development and implementation of NIPT. Results: There are many patents held by many parties internationally, with litigation over these patents ongoing in many countries. Importantly, there are significant international differences in patent law, with patents invalidated in the USA that remain valid in Europe. Despite the many patents and ongoing litigation, there are multiple providers of testing internationally, and patents do not appear to be preventing patient access to testing for those who can pay out of pocket. Conclusion: The patent situation in NIPT remains in a state of flux, with uncertainty about how patent rights will be conferred in different jurisdictions, and how patents might affect clinical access. However, patents are unlikely to result in a monopoly for a single provider, with several providers and testing technologies, including both public and private sector entities, likely to remain engaged in delivery of NIPT. However, the effects on access in public healthcare systems are more complex and need to be monitored.Economic and Social Research Council (ESRC)Australian Research CouncilNational Institute for Health Research (NIHR

The Functional and Identity Indispensability Scale (FIIS)

This research further elaborated the concept of indispensability by developing and testing a new measure, the Functional and Identity Indispensability Scale (FIIS), to assess two dimensions on which groups can claim indispensability: functional indispensability and identity indispensability. In Study 1 we developed and validated the FIIS with a sample of 452 American college students. Results showed the expected two-factor structure and supported the prediction that identity and functional are two distinct, but related, forms of indispensability. FIIS showed a consistent structure across majority and minority members and the reliability of the two subscales was good. In Study 2, a sample of 154 White-American citizens evaluated the perceived indispensability (FIIS) of three minority groups: African-Americans, Hispanic-Americans, and Asian-Americans. Results showed the scale’s sensitivity. Participants attributed greater identity (vs. functional) indispensability to African-Americans, whereas the pattern was reversed for Asian-Americans. No differences were found for Hispanic-Americans. Criterion validity was supported by (a) positive associations with competence and warmth, (b) negative associations with negative emotions and with social distance towards all minority group targets. The psychometric properties of the FIIS suggest its potential to be valuable addition to the existing literature on common identities and intergroup relations.info:eu-repo/semantics/acceptedVersio

Lattice Model of Sweeping Interface for Drying Process in Water-Granule Mixture

Based on the invasion percolation model, a lattice model for the sweeping interface dynamics is constructed to describe the pattern forming process by a sweeping interface upon drying the water-granule mixture. The model is shown to produce labyrinthine patterns similar to those found in the experiment[Yamazaki and Mizuguchi, J. Phys. Soc. Jpn. \textbf{69} (2000) 2387]. Upon changing the initial granular density, resulting patterns undergo the percolation transition, but estimated critical exponents are different from those of the conventional percolation. Loopless structure of clusters in the patterns produced by the sweeping dynamics seems to influence the nature of the transition.Comment: 6 pages, 7 figure

Persistent holes in a fluid

We observe stable holes in a vertically oscillated 0.5 cm deep aqueous suspension of cornstarch for accelerations a above 10g. Holes appear only if a finite perturbation is applied to the layer. Holes are circular and approximately 0.5 cm wide, and can persist for more than 10^5 cycles. Above a = 17g the rim of the hole becomes unstable producing finger-like protrusions or hole division. At higher acceleration, the hole delocalizes, growing to cover the entire surface with erratic undulations. We find similar behavior in an aqueous suspension of glass microspheres.Comment: 4 pages, 6 figure

Turning down the lamp: Software specialisation for the cloud

© USENIX Workshop on Hot Topics in Cloud Computing, HotCloud 2010.All right reserved. The wide availability of cloud computing offers an unprecedented opportunity to rethink how we construct applications. The cloud is currently mostly used to package up existing software stacks and operating systems (e.g. LAMP) for scaling out websites. We instead view the cloud as a stable hardware platform, and present a programming framework which permits applications to be constructed to run directly on top of it without intervening software layers. Our prototype (dubbed Mirage) is unashamedly academic; it extends the Objective Caml language with storage extensions and a custom run-time to emit binaries that execute as a guest operating system under Xen. Mirage applications exhibit significant performance speedups for I/O and memory handling versus the same code running under Linux/Xen. Our results can be generalised to offer insight into improving more commonly used languages such as PHP, Python and Ruby, and we discuss lessons learnt and future directions

Environmental disclosure in Spain: Corporate characteristics and media exposure

Social and environmental issues have become a major concern for accounting research over the past two decades. Social and Environmental Accounting has attracted the attention of a number of researchers attempting to understand, explain and predict the disclosure of information on the social and environmental implications of business activities. Empirical research has hypothesized that size, profitability and the potential environmental impact of the firm are the main factors explaining the amount of information disclosed. On the other hand, several studies have focused on the motivations for disclosing environmental information, hypothesizing that disclosures are aimed at building or sustaining corporate legitimacy. We test the main hypotheses developed to date by empirical research with regard to the disclosure of environmental information based on a sample of companies listed on the Madrid Stock Exchange. Results of a content analysis show that firms disclosing environmental information tend to be larger, have higher risk (measured by the beta coefficient) and operate in industries that have a high potential environmental impact. The environmental implications of the activities carried out by these companies also seem to receive more attention from print media. Our results also provide evidence that two factors directly associated with the amount of environmental information disclosed are the potential environmental impact of the industry and the extent of media coverage of the firms