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The purpose of this study is to examine theoretically the axisymmetric flow of a steady free-surface jet emerging from a tube for high inertia flow and moderate surface tension effect.

The method of matched asymptotic expansion is used to explore the rich dynamics near the exit where a stress singularity occurs. A boundary layer approach is also proposed to capture the flow further downstream where the free surface layer has grown significantly.

The jet is found to always contract near the tube exit. In contrast to existing numerical studies, the author explores the strength of upstream influence and the flow in the wall layer, resulting from jet contraction. This influence becomes particularly evident from the nonlinear pressure dependence on the upstream distance, as well as the pressure undershoot and overshoot at the exit for weak and strong gravity levels, respectively. The approach is validated against existing experimental and numerical data for the jet profile and centerline velocity where good agreement is obtained. Far from the exit, the author shows how the solution in the diffusive region can be matched to the inviscid far solution, providing the desired appropriate initial condition for the inviscid far flow solution. The location, at which the velocity becomes uniform across the jet, depends strongly on the gravity level and exhibits a non-monotonic behavior with respect to gravity and applied pressure gradient. The author finds that under weak gravity, surface tension has little influence on the final jet radius. The work is a crucial supplement to the existing numerical literature.

Given the presence of the stress singularity at the exit, the work constitutes a superior alternative to a computational approach where the singularity is typically and inaccurately smoothed over. In contrast, in the present study, the singularity is entirely circumvented. Moreover, the flow details are better elucidated, and the various scales involved in different regions are better identified.

This paper aims to show that simple geometry‐based hp‐algorithms using an explicit a posteriori error estimator are efficient in wave propagation computation of complex structures containing geometric singularities.

Four different hp‐algorithms are compared with common h‐ and p‐adaptation in electrostatic and time‐harmonic problems regarding efficiency in number of degrees of freedom and runtime. An explicit a posteriori error estimator in energy norm is used for adaptive algorithms.

Residual‐based error estimation is sufficient to control the adaptation process. A geometry‐based hp‐algorithm produces the smallest number of degrees of freedom and results in shortest runtime. Predicted error algorithms may choose inappropriate kind of refinement method depending on p‐enrichment threshold value. Achieving exponential error convergence is sensitive to the element‐wise decision on h‐refinement or p‐enrichment.

Initial mesh size must be sufficiently small to confine influence of phase lag error.

Information on implementation of hp‐algorithm and use of explicit error estimator in electromagnetic wave propagation is provided.

The paper is a resource for developing efficient finite element software for high‐frequency electromagnetic field computation providing guaranteed error bound.

Magnetostatic problems including iron components can be solved by a nonlinear indirect volume integral equation. Its unknowns are scalar field sources. They are evaluated iteratively. In doing so the integral representation of fields has to be calculated. At edges singularities occur. Following a method to calculate the field strength on charged surfaces a way out is presented.

This study aims to analyze the impact of different exit alternatives, investor presence and founders’ human capital on the exit value of European venture capital (VC)-backed high technology startups.

The empirical analysis is based on a sample of 107 European firms that obtained an exit through Merger&Acquisition (M&A) or an initial public offering (IPO) between 2010 and 2017, backed by VC investors.

This study provides empirical evidence on how different exit alternatives, investor heterogeneity and founders’ human capital may affect the exit value of European VC-backed startups. Exiting through an IPO and retaining a larger equity stake are positively correlated with the exit value. The presence of business angels and non-governmental VC firms is associated with larger valuations. Founders’ previous education was positively correlated with the exit value.

Exit strategies in technology startups are essential to capitalize investors’ efforts and reinvest cash into new ventures, supporting the development of entrepreneurial ecosystems and countries’ competitiveness. The results of this study provide interesting hints for policymakers and contribute to an in-depth understanding of the drivers of exit valuation for startups.

A hybrid spectral/boundary element approach is proposed to examine the influence of Couette channel flow on transient coating of highly elastic fluids. The viscoelastic instability of one‐dimensional plane Couette flow is first determined for a large class of Oldroyd fluids with added viscosity, which typically represent polymer solutions composed of a Newtonian solvent and a polymeric solute. The Johnson‐Segalman equation is used as the constitutive model. The velocity profile inside the channel is taken as the exit profile for the emerging free‐surface flow. The flow is assumed to be Newtonian as it emerges from the channel. An estimate of the magnitude of the rate‐of‐strain tensor components in the free‐surface region reveals that they are generally smaller than the shear rate inside the channel. The evolution of the flow front is simulated using the boundary element method. For the channel flow, the problem is reduced to a non‐linear dynamical system using the Galerkin projection method. Stability analysis indicates that the channel velocity may be linear or non‐linear depending on the range of the Weissenberg number. The evolution of the coating flow at the exit is examined for steady as well as transient (monotonic and oscillatory) channel flow. It is found that adverse flow can exist as a result of fluid elasticity, which can hinder the process of blade coating.

On Justification: Economies of Worth (Boltanski & Thévenot, 1991/2006) was a synthetic and comprehensive parsing of common goods, goods that could and had to be justified in public. In response to Bourdieu’s critical sociology, they rather provided a robust and disciplined sociology of critique, the situated requirements of justification. They refused power and violence as integral to the operability of justification. They emphasized the ways in which conventions of worth afforded coordination, not their constitution of or by domination. They refused to make either capitalism, or the state, into primary motors of social order. Indeed, they refused social sphere, structure, or group as the ground of the good. They emphasized the cognitive capacities of agents. There was no passion, no desire, no bodily affect in these justified worlds. There wasn’t even any account of production of value, of children, or of money. And while they recognized the metaphysical aspect of the good and even used Christianity as a template for one of their cités, they rigorously excluded religion. The theory was designed to analyze moments of controversy, not quiescence or quietude. In his subsequent work, Boltanski aimed to address these absences. In this essay, we examine how Boltanski sought to restore love, violence, religion, production, and institution across five texts: Love and Justice as Competences (1990/2012), The New Spirit of Capitalism, co-authored with Eve Chiapello (1999/2007), The Foetal Condition: A Sociology of Engendering and Abortion (2004/2013), On Critique: A Sociology of Emancipation (2009/2011), and La «Collection», Une Forme Neuve du Capitalisme – La Mise en Valeur Economique du Passé et ses Effets (2014) co-authored with Arnaud Esquerre.

The research aims to examine the underlying factors of entrepreneurial intentions among seniors. In this vein, it evaluates the role of social context proxied by the human development index (HDI) along with individual characteristics towards these initiatives. Emerging economies deliver great potential for income generation swiftly approaching the standards of their developed counterparts. Their present ageing trends severely threaten growth prospects because of workforce withering. European insights will help anticipating constraints through alternative models of human capital allocation.

Four logistic regressions were run to address hypotheses in test, relying upon the global entrepreneurship monitor – adult population survey. Estimations include 20,386 individuals from database and 21 European Union countries. Ex-post robustness checks corroborate the global significance of the proposed model.

Empirical findings reinforce the importance of the macroeconomic context among senior endeavours and the non-linearities in terms of the age effect. Moreover, context can help eroding gender gaps in this field and refine the opportunity perception These results go in line with the literature and extend the importance of promoting a favourable ecosystem. Promotion of senior endeavours must consider smart policy packages encompassing the individual singularities as this age range will be too important to be wasted. Senior entrepreneurs are key to the latent job market crisis, needing to be encouraged through positive discrimination.

Originally, by incorporating an exogenous variable encompassing the role of the entrepreneurial context, this study contributes academically to evaluating the determinants of entrepreneurial activity among the elderly. In addition, the development of cohorts highlights the specific importance of individual characteristics in entrepreneurial propensity in each context. The heterogenous results proves the ineffectiveness of “one sizes fits all” policies.

This research reinforces extant literature, notwithstanding the empirical refinements implemented brought up two additional perspectives: complementing previous towards the relevance of HDI cohorts along with the non-linearities of the effect of age. Learning from the European context and acknowledging efficacy of policy instruments will avoid serendipitous actions or failures, enhancing promising ecosystems such as emerging economies.

The study academically contributes to the appraisal of the determinants of entrepreneurial activity among seniors, thus, in an original way, by incorporating an exogenous variable to appraise the role of the context. Development cohorts evidence the existence of singularities in entrepreneurial propensity and individual characteristics according to their levels, such that policy actions should consider their differences.

This paper seeks to explore the fiber orientation distribution and rheological properties of turbulent fiber suspensions flowing through a contraction.

The Reynolds averaged Navier‐Stokes equation was solved with the Reynolds stress model to get the mean fluid velocity and the turbulent kinetic energy in the turbulent flow of a contraction with rectangular cross‐section. The turbulent velocity fluctuations were represented as a Fourier series with random coefficients. Then the slender‐body theory was used to predict the fiber orientation distribution, orientation tensor, additional shear stress and first normal stress difference of suspensions in the flow.

It is found that the longer fibers tend to align the streamline easily. Increased contraction ratio results in higher fiber alignment in the direction of flow. The fibers are weakly and strongly aligned in the direction of flow in the region near the inlet and the exit, respectively. Fibers are significantly more aligned in the plane of the contraction than in the x‐z plane. Contraction ratio and fiber length were shown to strongly and weakly affect the distributions of additional shear stress and first normal stress difference.

It is the first time that the fiber orientation distribution and rheological properties of turbulent fiber suspensions flowing through a contraction have been computed numerically. The computational approach and results are valuable to the design and operation of contraction used in the industrial processes.

The European Union (EU) is not a state, though it has some statelike attributes; it is not an empire, though it includes many former European imperial powers; and it is not a federation, though Euro-federalists seek to make it one. There is, however, no need to argue that the Union is a singularity, nor to invent novel terminology, such as that deployed by “neo-functionalists” and “intergovernmentalists” to capture its legal and political form. The EU is a confederation, but with consociational characteristics in its decision-making styles. This conceptualization facilitates understanding and helps explain the patterns of crises within the Union.

A computational procedure based on a hybrid Lagrangian‐Eulerian discrete‐vortical element formulation and conformal transformation schemes are employed in this study to simulate the interaction of an air jet with swirling air flow inside a two‐dimensional cylinder. Such an investigation is of importance to many flow‐related industrial and environmental problems, such as mixing, cooling, combustion and dispersion of air‐borne or water‐borne contaminants because of the role of vortices in the global transport of matter and heat. The basis for the simulation is discussed and numerical results compared with theoretical results for the velocity field and streamfunction obtained by the method of images. The swirling air motion and the features of a real jet are well simulated and numerical results are validated by predictions of theory to within 20 per cent. To illustrate the merging and interaction processes of vortices and the formation of large eddies, velocity vectors, particle trajectories and streamline contours are presented.