Bubble Growth From First Principles

We consider the simplest relevant problem in the foaming of molten plastics, the growth of a single bubble in a sea of highly viscous Newtonian fluid, and without interference from other bubbles. This simplest problem has defied accurate solution from first principles. Despite plenty of research on foaming, classical approaches from first principles have neglected the temperature rise in the surrounding fluid, and we find that this oversimplification greatly accelerates bubble growth prediction. We use a transport phenomena approach to analyze the growth of a solitary bubble, expanding under its own pressure. We consider a bubble of ideal gas growing without the accelerating contribution from mass transfer into the bubble. We explore the roles of viscous forces, fluid inertia, and viscous dissipation. We find that bubble growth depends upon the nucleus radius and nucleus pressure. We begin with a detailed examination of the classical approaches (thermodynamics without viscous heating). Our failure to fit experimental data with these classical approaches, sets up the second part of our paper, a novel exploration of the essential decelerating role of viscous heating. We explore both isothermal and adiabatic bubble expansion, and also the decelerating role of surface tension. The adiabatic analysis accounts for the slight deceleration due to the cooling of the expanding gas, which depends on gas polyatomicity. We also explore the pressure profile, and the components of the extra stress tensor, in the fluid surrounding the growing bubble. These stresses can eventually be frozen into foamed plastics. We find that our new theory compares well with measured bubble behavior.

The genesis of EC environmental principles. Research Paper in Law 7/2003

[From the Introduction]. The EC Treaty in its present version contains a number of environmental principles. The following contribution will try to retrace the origins of these principles in the EC Treaty and how they were developed by the EC institutions and in particular by the Commission. This discussion concerns the principles of integration[1], prevention[2] and precaution[3], the principle that environmental damage should as a priority be rectified at source[4] and the polluter-pays principle[ 5].

Principles of a Two-Tier European Deposit (Re-)Insurance System. CEPS Policy Brief No. 287, 17 April 2013.

There is general agreement that banking supervision and resolution have to be organised at the same level. It is often argued, however, that there is no need to tackle deposit insurance because it is too politically sensitive. This note proposes to apply the principles of subsidiarity and re-insurance to deposit insurance: Existing national deposit guarantee schemes (DGSs) would continue to operate much as before (with only minimal standards set by an EU directive), but they would be required to take out re-insurance against risks that would be too large to be covered by them. A European Reinsurance Fund (EReIF) would provide this reinsurance financed by premia paid by the national DGSs, just as any reinsurance company does in the private sector. The European Fund would pay out only in case of large losses. This ‘deductible’ would provide the national authorities with the proper incentives, but the reinsurance cover would stabilize depositor confidence even in the case of large shocks. Ideally the national DGSs would be responsible also for resolution. Experience has shown banking systems are more stable if deposit insurers are also responsible for resolution. The approach proposed here could thus be also used to design the ‘Single Resolution Mechanism’ (SRM) which is being discussed as a complement to the ‘Single Supervisory Mechanism’ (SSM). It will of course take time to build up the funding for such a reinsurance fund. This approach is thus not meant to deal with legacy problems from the current crisis.

European Criminal Law and General Principles of Union Law. Research Papers in Law, 5/2005

From the Introduction. The European Court of Justice, partly followed in this by the European legislator, has regulated Community law and policy through a set of general principles of law. For the Community legal order in the first pillar, general legal principles have developed from functional policy areas such as the internal market, the customs union, the monetary union, the common agricultural policy, the European competition policy, etc., which are of great importance for the quality and legitimacy of Community law. The principles in question are not so much general legal principles of an institutional character, such as the priority of Community law, direct effect or Community loyalty, but rather principles of law which shape the fundamental rights and basic rights of the citizen. I refer to the principle of legality, of nulla poena, the inviolability of the home, the nemo tenetur principle, due process, the rights of the defence, etc. Many of these legal principles have been elevated to primary Community law status by the European Court of Justice, often as a result of preliminary questions. Nevertheless, a considerable number of them have also been elaborated in the context of contentious proceedings before the Court of Justice, such as in the framework of European competition law and European public servants law.

Decentralisation of EC Competition Law Enforcement and General Principles of Community Law. Research Papers in Law, 4/2004

From the Introduction. By virtue of Council Regulation No. 1/2003, as of 1st May 2004 the full application of EC competition law will be entrusted to national competition authorities (hereinafter NCAs) and national courts. The bold reform of EC competition law enforcement adheres to the system of executive federalism1 which characterises the EC legal system. The repartition of competences within the Community allocates implementation of Community law mainly at Member States level. Pursuant to Article 10 EC, they are responsible for the implementation of the measures which have been adopted at Community level for the achievement of the objectives specified in the EC Treaty. Consequently, the attainment of the Community objectives depends very much upon the cooperation of national authorities, which act in accordance with their own national procedural rules.2 The various national procedural rules present themselves as conduits through which Community law is implemented and enforced. While as a rule Community law is not designed to alter national procedural rules, the Community legal order cannot afford to leave national procedural rules untouched when they are liable to hamper the effective application of Community law....For reason of space, this contribution intends only to highlight some aspects of Regulation No. 1/2003 with regard to which general principles of Community law are able to condition national procedural rules.