Deformation of an elastic cell in a uniform stream and in a circulatory flow

The deformation of a circular, inextensible elastic cell is examined when the cell is placed into two different background potential flows: a uniform stream and a circulatory flow induced by a point vortex located inside the cell. In a circulatory flow a cell may deform into a mode m shape with m-fold rotational symmetry. In a uniform stream, shapes with two-fold rotational symmetry tend to be selected. In a weak stream a cell deforms linearly into an ellipse with either its major or its minor axis aligned with the oncoming flow. This marks an interesting difference with a bubble with constant surface tension in a uniform stream, which can only deform into a mode 2 shape with its major axis perpendicular to the stream (Vanden-Broeck & Keller, 1980b). In general, as the strength of the uniform stream is increased from zero, solutions emerge continuously from the cell configurations in quiescent fluid found by Flaherty et al. (1972). A richly populated solution space is described with multiple solution branches which either terminate when a cell reaches a state with a point of self-contact or loop round to continuously connect cell states which exist under identical conditions in the absence of flow

Benjamin-Ono Kadomtsev-Petviashvili’s models in interfacial electro-hydrodynamics

Three-dimensional nonlinear potential free surface flows in the presence of vertical electric fields are considered. Both the effects of gravity and surface tension are included in the dynamic boundary condition. An asymptotic analysis (based on the assumptions of small depth and small free surface displacements) is presented. It is shown that the problem can be modelled by a Benjamin-Ono Kadomtsev-Petviashvili equation. Furthermore a fifth order Benjamin-Ono Kadomtsev-Petviashvili equation is derived to describe the flows in the particular case of values of the Bond number close to 1/3

Trapped waves on interfacial hydraulic falls over bottom obstacles

Hydraulic falls on the interface of a two-layer density stratified fluid flow in the presence of bottom topography are considered. We extend the previous work [Philos. Trans. R. Soc. London A 360, 2137 (2002)] to two successive bottom obstructions of arbitrary shape. The forced Korteweg-de Vries and modified Korteweg-de Vries equations are derived in different asymptotic limits to understand the existence and classification of fall solutions. The full Euler equations are numerically solved by a boundary integral equation method. New solutions characterized by a train of trapped waves are found for interfacial flows past two obstacles. The wavelength of the trapped waves agrees well with the prediction of the linear dispersion relation. In addition, the effects of the relative location, aspect ratio, and convexity-concavity property of the obstacles on interface profiles are investigated

Existence and conditional energetic stability of three-dimensional fully localised solitary gravity-capillary water waves

In this paper we show that the hydrodynamic problem for three-dimensional water waves with strong surface-tension effects admits a fully localised solitary wave which decays to the undisturbed state of the water in every horizontal direction. The proof is based upon the classical variational principle that a solitary wave of this type is a critical point of the energy subject to the constraint that the momentum is fixed. We prove the existence of a minimiser of the energy subject to the constraint that the momentum is fixed and small. The existence of a small-amplitude solitary wave is thus assured, and since the energy and momentum are both conserved quantities a standard argument may be used to establish the stability of the set of minimisers as a whole. `Stability' is however understood in a qualified sense due to the lack of a global well-posedness theory for three-dimensional water waves.Comment: 83 pages, 1 figur

Effect of the C/N ratio modification on the corrosion behavior and performance of carbonitride coatings prepared by cathodic arc deposition

This study focuses on investigating carbonitride coatings, specifically CNTi-(Zr, ZrNb, and ZrSi), as promising candidates for enhancing the durability and efficiency of Ti6Al4V materials used in nuclear fusion technology. X-ray diffraction analysis identified distinct phases, including TiN, ZrN, ZrC, and TiC. The corrosion studies showed complete degradation of the TiN, ZrC, and ZrN phases in the TiZrCN coating after tests, while the TiC phase exhibited relative stability. The surface morphologies and elemental mapping analysis demonstrated the loss of homogeneity in element distribution after corrosion process. The addition of Si and Nb elements into TiZrCN significantly influenced the coatings' corrosion behavior, with breakaway corrosion observed in CNTi- (Zr and ZrSi) coatings and localized corrosion in CNTi-(ZrNb) coatings. Notably, the CNTi-(ZrSi) coating formed an oxide phase in the presence of NaCl, whereas the CNTi-(ZrNb) coating exhibited continuous resistance and a low corrosion rate. Irradiation was carried out for the generation of active isotopes, showing that no radioactive isotopes were formed in any of the investigated samples

A study of the effects of electric field on two-dimensional inviscid nonlinear free surface flows generated by moving disturbances

Two-dimensional free surface flows generated by a moving disturbance are considered. The flows are assumed to be potential. The effects of electric field, gravity and surface tension are included in the dynamic boundary condition. The disturbance is chosen to be a distribution of pressure moving at a constant velocity. Both linear and nonlinear results are presented. For some values of the parameters, the linear theory predicts unbounded displacements of the free surface. It is shown that this nonuniformity is removed by developing a weakly nonlinear theory. There are then solutions which are perturbations of a uniform stream and others which are perturbations of solitary waves with decaying tails

Markers for tumor margin assessment through raman spectroscopy in comparative oncology

The occurrence of tumour diseases in both animals and humans is continuously increasing. Research in nanosciences and molecular biology has put lately an intense effort to identify the aetiology factors and seek for new ways of diagnostic and targeted therapies aimed at reducing mortality and increasing chances to healing. Extensive development of cancer tumours is frequently counteracted through surgery. Assessment of a clean surgical margin is vital and a precise and rapid diagnostic down to molecule level represents a technical challenge with important clinical implications. We present a new way of using surgery instruments and surface enhanced Raman spectroscopy for direct ex vivo (no freezing, no staining) and in vivo diagnostic of clean margins in mammary tumour surgery of pets (dogs and cats).Raman spectroscopy extracts chemical information with reported 100%sensitivity, 100% specificity and overall accuracy of 93% in identifying carcinomas. Our main result stays in identification of a set of molecular markers (carotenoids, lipids and intramolecular water) for Raman diagnostic in cat and dog mammary tumour surgery. Those markers have already been confirmed for human patients

The 2014 European elections in Britain : the counter-revolt of the masses?

This article reviews the campaign manifestoes of the main political parties vying in the UK's 2014 European Parliamentary elections, and analyses the electoral results. The most newsworthy event has been the meteoric rise of the United Kingdom Independence Party (UKIP), a vehemently Eurosceptic party advocating withdrawal from the EU. UKIP beat both mainline parties (Labour and the Conservatives) even while the vote collapsed for the UK's most Europhile party, the Liberal Democrats. Even more important is the influence UKIP has now won to affect the domestic electoral strategies of the Conservative and Labour Parties, with which it competes for the Eurosceptic centre-right and anti-immigration working-class vote, respectively. The Conservatives, in Coalition with the Liberal Democrats since 2010, were forced to reshuffle their Cabinet to give Eurosceptic MPs a higher profile; to pass a European Union Act mandating an in-out referendum on EU membership in 2017; and to persuade the EU to appoint a British Conservative to head the European Commission’s Financial Services Directorate. UKIP’s success has been stirring both fears and hopes for the (domestic) general election of 2015. An anti-statist party that combines elements of libertarianism and nationalism, UKIP may well come to embody the revolt of the masses against the British establishment

East Side story: how transnational networks contested EU accession conditionality

The literature on Europeanisation in relation to Eastern Europe has posited the material incentives of EU membership as the main driver of domestic reforms aimed at adopting EU rules and norms (conditionality). But this fails to explain puzzling instances where no EU rule exists yet domestic change happens under European influence, or where the rule is a condition yet has little impact. As repositories of (dis)information, transnational networks can embolden a candidate country to breach the rules or influence it to comply with the ‘extra-conditionality’ the networks themselves create out of their own agendas