We describe the breakup of a confined gas thread in a cross-flowing stream of liquid at capillary numbers Ca < 10(-2). The breakup is initiated, not by a Plateau-Rayleigh instability, but by... Show moreWe describe the breakup of a confined gas thread in a cross-flowing stream of liquid at capillary numbers Ca < 10(-2). The breakup is initiated, not by a Plateau-Rayleigh instability, but by liquid that flows from the tip of the thread to the neck where pinch-off occurs. This flow, faster than previously estimated, is driven by different curvatures at the tip and neck and runs through large gaps between thread and channel walls. Understanding how these curvatures evolve during bubble formation leads to accurate predictions of the moment of pinch-off. Show less
This paper explores how to strengthen the research‐teaching nexus in university education, in particular, how to improve the relation between policy and practice. The focus is on courses and... Show moreThis paper explores how to strengthen the research‐teaching nexus in university education, in particular, how to improve the relation between policy and practice. The focus is on courses and curricula for undergraduate students. From a review of policy documents and research literature, it appeared that the research‐teaching nexus can be shaped according to two dimensions. One concerns an emphasis on either the research content and products, or the research processes and problems; the other concerns the role of students as either learning existing insights, or as ‘participants in research’ who contribute to insights which are new to the field (e.g., by conducting research themselves). It is concluded that if a university chooses to strengthen the research‐teaching nexus in undergraduate curricula, this implies involving students more often in the role of participants in research. Show less
van Swet, Jacqueline; Smit, Ben H.J.; Corvers, Louise; van Dijk, Ineke 2009
This article reports on an action research project in which the value of criticalfriendship for students doing research and writing their dissertations within aninternational master’s course has... Show moreThis article reports on an action research project in which the value of criticalfriendship for students doing research and writing their dissertations within aninternational master’s course has been explored. This course is run jointly byRoehampton University (London, UK), Charles University (Prague, CzechRepublic) together with Fontys OSO (Tilburg, the Netherlands). It describes theprocess and the results of working with the concept of critical friendship in thismaster’s course since its start in 2005. Data were collected by means of variousqualitative instruments and data sources: evaluation forms after tutorial sessions,reflective logs and focus interviews. The results show that the process of engagingwith the research they did was enhanced and supported by the development ofcritical friendship groups. A number of recommendations have been formulated,such as the importance of discussing the concept of critical friend and itsphilosophy with the participants and of defining roles and tasks as clearly aspossible. Show less
California's water transfer system depends on the Sacramento-San Joaquin Delta to move water. Unfortunately, the Delta's ecosystem appears to be suffering from this use -- and other uses. After... Show moreCalifornia's water transfer system depends on the Sacramento-San Joaquin Delta to move water. Unfortunately, the Delta's ecosystem appears to be suffering from this use -- and other uses. After discussing the stakeholders in the Delta, the causes of ecological decline, and the choices for change (including a radical political-economic market), I conclude that business-as-usual is over, that any solution is costly, and that the politicians and bureaucrats in the middle of this process benefit from conflict and inaction. The Delta will remain broken for the foreseeable future. Show less
Present paper introduces a new evolutionary technique for multimodal real-valued optimization which uses a clustering method for separating the individuals within a population into species that are... Show morePresent paper introduces a new evolutionary technique for multimodal real-valued optimization which uses a clustering method for separating the individuals within a population into species that are each connected to different optima from the search space. It is applied for a set of benchmark functions both for uni- and multimodal optimization and it proves to be very efficient as regards both the accuracy of the obtained results and the costs regarding the fitness evaluation calls that are spent. Show less
Mainhard, M.T.; Rijst, R.M. van der; Tartwijk, J. van; Wubbels, T. 2009
