Liquid morphologies and capillary forces between three spherical beads

Equilibrium shapes of coalesced pendular bridges in a static assembly of spherical beads are computed by numerical minimization of the interfacial energy. Our present study focuses on generic bead configurations involving three beads, one of which is in contact to the two others while there is a gap of variable size between the latter. In agreement with previous experimental studies, we find interfacial `trimer' morphologies consisting of three coalesced pendular bridges, and `dimers' of two coalesced bridges. In a certain range of the gap opening we observe a bistability between the dimer and trimer morphology during shrinking and growth. The magnitude of the corresponding capillary forces in presence of a trimer or dimer depends, besides the gap opening only on the volume or Laplace pressure of liquid. For a given Laplace pressure, the capillary forces in presence of a trimer are slightly larger than the force of a single bridges at the same gap opening, which could explain the shallow maximum and plateau of the capillary cohesion of a wetting liquid for saturations in the funicular regime

The Politics of (Non)Knowledge in the (Un)Making of Migration

In the past decade, constructivist understandings of migration have gained momentum in migration studies. Scholars have shown how (some) people are enacted as ›migrants‹ when human mobility clashes with nation‐states’ claimed prerogative to control »the legitimate means of movement« (Torpey). Another body of scholarship has highlighted the crucial role played by knowledge practices in the enactment of migration as an intelligible object of government. However, these two lines of inquiry have largely been conducted independently of each other. To better account for how practices of border control affect the production of knowledge about migration and how the latter, in turn, informs practices and rationales of migration management, this article asks: How can we conceptualize and empirically investigate the relationship between enacting migration through knowledge practices and enacting migrants through practices of bordering? In response to this question, I propose a sociology of translation and treason in the tradition of the Actor‐Network Theory (ANT), which enables tracing how records produced in border encounters are translated into not only ›migration facts‹ but also various forms of nonknowledge. To demonstrate the analytical potential of this approach, I show how statistical knowledge about the ›deportation gap‹ – often invoked to justify ever‐more restrictive measures in the field of return policy – is, to a significant extent, a result of the mistranslation of returned migrants in administrative records used for migration statistics. Zur Politik des (Nicht‐)Wissens in der Herstellung/dem Rückgängigmachen von Migration In den letzten Jahren haben konstruktivistische Ansätze in der Migrationsforschung an Bedeutung gewonnen. Zahlreiche Forscher*innen haben gezeigt, wie einige Subjekte zu Migranten gemacht werden, wenn Mobilität mit dem von Nationalstaaten beanspruchten Recht kollidiert, »die legitimen Mittel der Bewegung« (Torpey) zu kontrollieren. Ein zweiter Forschungsbereich hat die Rolle von Wissenspraktiken bei der Konstitution von Migration als einem Objekt des Regierens aufgezeigt. Bislang wurden diese beiden Forschungsrichtungen zumeist unabhängig voneinander betrieben. Um besser zu verstehen, wie Praktiken der Grenzkontrolle die Produktion von Wissen über Migration beeinflussen, und wie Letztere Praktiken und Logiken des Grenz‐ und Migrationsmanagements prägt, fragt dieser Artikel: Wie lässt sich die Beziehung zwischen der Konstituierung von Migration als einem Objekt des Regierens durch Wissensproduktion und die Konstitution von Migrant*innen durch Praktiken der Grenzkontrolle theoretisch denken und empirisch erforschen? Hierfür wird eine Soziologie der Übersetzung und des Betrugs in Tradition der Akteur‐Netzwerk‐Theorie (ANT) vorgeschlagen. Dieser Ansatz erlaubt es zu untersuchen, wie administrative Daten, die Begegnungen zwischen mobilen Subjekten und Akteuren der Grenzkontrolle generiert werden, in Fakten bzw. in Nicht‐Wissen über Migration übersetzt werden. Um das analytische Potential dieses Ansatzes zu demonstrieren, zeige ich, wie statistisches Wissen über den ›deportation gap‹, der häufig bemüht wird, um restriktivere Maßnahmen im Bereich der Rückkehrpolitik zu legitimieren, zu einem signifikanten Teil auf der Nicht‐Übersetzung von remigierten Migrant*innen in administrative Daten beruht, die für die Produktion von Migrationsstatistiken genutzt werden

Doing statistics, enacting the nation: the performative powers of categories

It has been widely acknowledged in debates about nationalism and ethnicity that identity categories used for classifying people along the lines of culture, race and ethnicity help to enact, that is bring into being, the collective identities they name. However, we know little about how categories acquire their performative powers. The contribution of this paper is twofold: first, it proposes a conceptual framework based on concepts and insights from science and technology studies (STS) for investigating the performative powers of statistical identity categories and possibly also other domains. Second, it demonstrates, through an empirical study of two examples in Estonian and Dutch official population statistics, that statistical identity categories enact more than the groups to which they refer. We argue that they also enact national identities and notions of national belonging of majoritarian groups in the host countries. Therefore, statistical identity categories can be used as analytical lenses to study nationalisms and processes of nation-building

Who is a Migrant? Abandoning the Nation-state Point of View in the Study of Migration

This article develops an alternative definition of a migrant that embraces the perspective of mobility. Starting from the observation that the term ‘migrant’ has become a stigmatizing label that problematizes the mobility or the residency of people designated as such, we in-vestigate the implications of nation-state centered conceptions of migration which define migration as movement from nation-state A to nation-state B. By asking ‘Who is a migrant in Europe today?’ we show that nation-state centered understandings of migration rest on a deeply entrenched methodological nationalism and implicate three epistemological traps that continue to shape much of the research on migration: first, the naturalization of the in-ternational nation-state order that results, secondly, in the ontologisation of ‘migrants’ as ready-available objects of research, while facilitating, thirdly, the framing of migration as problem of government. To overcome these epistemological traps, we develop an alternative conception of migration that, inspired by the autonomy of migration approach, adopts the perspective of mobility while highlighting the constitutive role that nation-states’ bordering practices play in the enactment of some people as migrants. Importantly, this definition al-lows to turn the study of instances of migrantisation into an analytical lens for investigating transformations in contemporary border and citizenship regimes

Das Europäische Grenzregime und die Autonomie der Migration: migrantische Kämpfe und die Versuche ihrer Regulation und Kontrolle [The European Border Regime and the Autonomy of Migration: Migrant Struggles and the attempts of controlling them]

Interest in migration has increased in recent years beyond the limits of the field of migration studies. Not the least because of the framing of migration as a security issue and strong anti-migration sentiments in many receiving societies migration also features on the agenda of peace studies. The latter is confronted with the challenge to develop alternatives modes of negotiating migration beyond defensive reactions outlined above. This requires however a basic knowledge of migration and its government. This chapter therefore introduces two central concepts of critical migration studies to interested readers: the notion of the border regime and the autonomy of migration approach

"The Secret is to Look Good on Paper”: Appropriating Mobility within and against a Machine of Illegalization

This chapter uses the introduction of the Visa Information System (VIS), a vast biometric database, as an opportunity to compensate for the relative neglect of the European visa regime in border and migration studies. Inspired by the autonomy of migration approach, the chapter engages the European visa regime from migrants’ perspective to study how migrants appropriate mobility via Schengen visa in the context of biometric border controls. The visa regime emerges as a vast machine of illegalisation that provokes precisely those practices of appropriation that it is meant to forestall. Illustrated through the example of the provision of manipulated feeder documents, the chapter subsequently outlines six features that practices of appropriation share irrespective of their form. Apart from demonstrating that moments of autonomy of migration persist within biometric border regimes, the chapter thus introduces the notion of appropriation as an alternative concept to theorise migrants’ capacity to subvert border controls

Peopling Europe through Data Practices: Introduction to the Special Issue

Politically, Europe has been unable to address itself to a constituted polity and people as more than an agglomeration of nation-states. From the resurgence of nationalisms to the crisis of the single currency and the unprecedented decision of a member state to leave the European Union (EU), core questions about the future of Europe have been rearticulated: Who are the people of Europe? Is there a European identity? What does it mean to say, “I am European?” Where does Europe begin and end? and Who can legitimately claim to be a part of a “European” people? The special issue (SI) seeks to contest dominant framings of the question “Who are the people of Europe?” as only a matter of government policies, electoral campaigns, or parliamentary debates. Instead, the contributions start from the assumption that answers to this question exist in data practices where people are addressed, framed, known, and governed as European. The central argument of this SI is that it is through data practices that the EU seeks to simultaneously constitute its population as a knowable, governable entity, and as a distinct form of peoplehood where common personhood is more important than differences