Memory-encoding vibrations in a disconnecting air bubble

Many nonlinear processes, such as the propagation of waves over an ocean or the transmission of light pulses down an optical fibre1, are integrable in the sense that the dynamics has as many conserved quantities as there are independent variables. The result is a time evolution that retains a complete memory of the initial state. In contrast, the nonlinear dynamics near a finite-time singularity, in which physical quantities such as pressure or velocity diverge at a point in time, is believed to evolve towards a universal form, one independent of the initial state2. The break-up of a water drop in air3 or a viscous liquid inside an immiscible oil4,5 are processes that conform to this second scenario. These opposing scenarios collide in the nonlinearity produced by the formation of a finite-time singularity that is also integrable. We demonstrate here that the result is a novel dynamics with a dual character

Effect of Transdermal Magnesium Cream on Serum and Urinary Magnesium Levels in Humans: A Pilot Study

© 2017 Kass et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background Oral magnesium supplementation is commonly used to support a low magnesium diet. This investigation set out to determine whether magnesium in a cream could be absorbed transdermally in humans to improve magnesium status. Methods and findings In this single blind, parallel designed pilot study, n=25 participants (aged 34.3+/-14.8y, height 171.5+/-11cm, weight 75.9 +/-14 Kg) were randomly assigned to either a 56mg/day magnesium cream or placebo cream group for two weeks. Magnesium serum and 24hour urinary excretion were measured at baseline and at 14 days intervention. Food diaries were recorded for 8 days during this period. Mg test and placebo groups’ serum and urinary Mg did not differ at baseline. After the Mg2+ cream intervention there was a clinically relevant increase in serum magnesium (0.82 to 0.89 mmol/l,p=0.29) that was not seen in the placebo group (0.77 to 0.79 mmol/L), but was only statistically significant (p=0.02)) in a subgroup of non-athletes . Magnesium urinary excretion increased from baseline slightly in the Mg2+ group but with no statistical significance (p=0.48). The Mg2+ group showed an 8.54% increase in serum Mg2+ and a 9.1% increase in urinary Mg2+ while these figures for the placebo group were smaller, i.e. +2.6% for serum Mg2+ and -32% for urinary Mg2+. In the placebo group, both serum and urine concentrations showed no statistically significant change after the application of the placebo cream. Conclusion No previous studies have looked at transdermal absorbency of Mg2+ in human subjects. In this pilot study, transdermal delivery of 56 mg Mg/day (a low dose compared with commercial transdermal Mg2+ products available) showed a larger percentage rise in both serum and urinary markers from pre to post intervention compared with subjects using the placebo cream, but statistical significance was achieved only for serum Mg2+ in a subgroup of non-athletes. Future studies should look at higher dosage of magnesium cream for longer durations.Peer reviewe

The inhibition of the Rayleigh-Taylor instability by rotation

It is well-established that the Coriolis force that acts on fluid in a rotating system can act to stabilise otherwise unstable flows. Chandrasekhar considered theoretically the effect of the Coriolis force on the Rayleigh-Taylor instability, which occurs at the interface between a dense fluid lying on top of a lighter fluid under gravity, concluding that rotation alone could not stabilise this system indefinitely. Recent numerical work suggests that rotation may, nevertheless, slow the growth of the instability. Experimental verification of these results using standard techniques is problematic, owing to the practical difficulty in establishing the initial conditions. Here, we present a new experimental technique for studying the Rayleigh-Taylor instability under rotation that side-steps the problems encountered with standard techniques by using a strong magnetic field to destabilize an otherwise stable system. We find that rotation about an axis normal to the interface acts to retard the growth rate of the instability and stabilise long wavelength modes; the scale of the observed structures decreases with increasing rotation rate, asymptoting to a minimum wavelength controlled by viscosity. We present a critical rotation rate, dependent on Atwood number and the aspect ratio of the system, for stabilising the most unstable mode

Application of the “Full Cavitation Model” to the fundamental study of cavitation in liquid metal processing

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.Ultrasonic cavitation treatment of melt significantly improves the downstream properties and quality of conventional and advanced metallic materials. However, the transfer of this technology has been hindered by difficulties in treating large volumes of liquid metal. To improve the understanding of cavitation processing efficiency, the Full Cavitation Model, which is derived from a reduced form of the Rayleigh-Plesset equation, is modified and applied to the two-phase problem of bubble propagation in liquid melt. Numerical simulations of the sound propagation are performed in the microsecond time scale to predict the maximum and minimum acoustic pressure amplitude fields in the domain. This field is applied to the source term of the bubble transport equation to predict the generation and destruction of cavitation bubbles in a time scale relevant to the fluid flow. The use of baffles to limit flow speed in a launder conduit is studied numerically, to determine the optimum configuration that maximizes the residence time of the liquid in high cavitation activity regions. With this configuration, it is then possible to convert the batch processing of liquid metal into a continuous process. The numerical simulations will be validated against water and aluminium alloy experiments, carried out at Brunel University.The UK Engineering and Physical Sciences Research Council (EPSRC) for financial assistance for this research in contract numbers: EP/K00588X/1 and EP/K005804/1

The interplay between European and national competition law after regulation 1/2003 : 'united (should) we stand?'

If we can speak of the European Community’s ‘economic constitution’, we can assert that competition rules, together with free movement rules, form its core. Notably, implementation of the competition rules enshrined in Articles 81 and 82 EC changed radically with the enactment of Regulation 1/2003, which in effect dispensed with mandatory prior notifications and allowed national authorities to apply Article 101(3) TFEU directly. Given that national legislations perceive certain types of unilateral conduct, even if adopted by a non-dominant undertaking, as a potential source of anticompetitive effects, an important question concerns the leeway enjoyed by national authorities under the exception to the convergence rule in Article 3(2) of Regulation 1/2003, and the consequent effect on both legal practice and policy issues. In this lucidly argued book, focusing on national competition provisions in Germany, France, Italy, and the United Kingdom that deal with such conduct, the author provides a detailed examination of how such considerations as the following are affected by Regulation 1/2003: -- prohibition of abuse of economic dependence or superior bargaining power; -- the particular susceptibility of long-term contracts; -- prohibition of resale at a loss or below cost; -- prohibition of boycott, unlawful pressures, threats, and other coercive tactics adopted by undertakings; and the role of unfair competition law. The analysis follows a functional method of comparative legal analysis, reviewing the most relevant norms in the selected jurisdictions, particularly in what concerns their goals and function in the context of their respective legal systems. Special attention is paid to two specific sectors – the motor-vehicle and the retailing industries – which have most often triggered relevant legislation and case law in the jurisdictions covered. Legal scholarship in the field is also drawn upon. In its clarification of the meaning of Regulation 1/2003, this book allows practitioners to fully grasp its scope. The author’s thorough, masterful analysis of the statutory framework of Article 3 of the regulation also reveals the variety of reasons why different Member States have different competition policies on the scope of the exception to the rule of convergence, and in this way provides lawyers, policymakers, and academics with welcome insights on how major EU jurisdictions apply European competition law.• Preface. • List of Abbreviations. • CHAPTER 1 Introduction. • CHAPTER 2 The Interplay between ECL and NCL before Regulation 1/2003. • CHAPTER 3 Interplay between ECL and NCL after Regulation 1/2003. • CHAPTER 4 Unilateral Conduct and Undertaking. • CHAPTER 5 Economic and Legal Perspectives on Market Power. • CHAPTER 6 National Provisions on the Abuse of Economic Dependence. • CHAPTER 7 Unilateral Conduct of Non-dominant Firms. • CHAPTER 8 Competition Issues and Unfair Trading Practices. • CHAPTER 9 Economic Insights on Superior Bargaining Power. • CHAPTER 10 Diversity and Competition Law. • CHAPTER 11 Unilateral Conduct and Unfair Competition Law. • CHAPTER 12 Unitas in Diversitate in Competition Law. • Annex. • Bibliography (Books, Chapters, Papers and Journals). • Documents, Reports and Studies. • Index.Published version of EUI PhD thesis, 201