Surface heat transfer due to sliding bubble motion

International audienc

‘We kind of try to merge our own experience with the objectivity of the criteria’: The role of connoisseurship and tacit practice in undergraduate fine art assessment

This article explores connoisseurship in the context of fine art undergraduate assessment practice. I interviewed twelve fine art lecturers in order to explore and unpack the concept of connoisseurship in relation to subjectivity, objectivity and tacit practice. Building on the work of Bourdieu (1973, 1977, 1986) and Shay (2003, 2005), both of whom problematize the view that subjectivity and objectivity are binary opposites, my research illustrates the ways that connoisseurship is underpinned by informed professional judgements located in communities of practice. Within this particular conception of connoisseurship, the lecturers’ expertise is co-constituted in communities of assessors through participation and engagement. Standards reside in communities of practice

Jet heat transfer in the vicinity of a rotating grinding wheel

Abstract: Impinging jets are known as a method of achieving high convective heat transfer coefficients. One potential application of impinging jet heat transfer is the air jet cooling of a grinding process. A grinding process generates heat that must be dissipated to avoid thermal damage. To date, this has been achieved using flood cooling with a traditional coolant such as an oil and water mixture; however, using a jet of air in its place has obvious environmental and economic benefits. For a range of grinding test configurations, results are presented of the convective heat transfer from the workpiece, along the notional plane of cut, and of the air flow velocity in a two-dimensional plane perpendicular to the workpiece. It has been shown that a boundary layer that develops around the rotating grinding wheel has the effect of displacing a peak in the distribution of the local heat transfer coefficient from the notional arc of cut. To effectively cool the grinding zone, therefore, it is necessary to penetrate this boundary layer and this can only be achieved when the jet velocity is substantially greater than the tangential velocity of the wheel

Effects of Capping on the (Ga,Mn)As Magnetic Depth Profile

Annealing can increase the Curie temperature and net magnetization in uncapped (Ga,Mn)As films, effects that are suppressed when the films are capped with GaAs. Previous polarized neutron reflectometry (PNR) studies of uncapped (Ga,Mn)As revealed a pronounced magnetization gradient that was reduced after annealing. We have extended this study to (Ga,Mn)As capped with GaAs. We observe no increase in Curie temperature or net magnetization upon annealing. Furthermore, PNR measurements indicate that annealing produces minimal differences in the depth-dependent magnetization, as both as-grown and annealed films feature a significant magnetization gradient. These results suggest that the GaAs cap inhibits redistribution of interstitial Mn impurities during annealing.Comment: 12 pages, 3 figures, submitted to Applied Physics Letter

Two Hands on the Wheel: Steering Robotics Innovation in Useful Directions

Practices of innovation are not autonomous. Research in STS and innovation studies has shown both the speed of knowledge production, and crucially its direction, may be susceptible to change. Indeed, interventions to the rate and direction of innovation are crucial if we are to address address the transformations needed in the economy and wider society that might for example avoid the extremes of climate change and meet the sustainable development goals. Yet interventions in these regards remain inexact. Innovation policy is one way in which government seeks to drive the production of policy towards or away from specific ends. Recent initiatives such as efforts to include "co-creation" have sought to open up innovation practices to a wider range of actors, broadening participation. But what arrangements of objects, sites, publics, and concepts do these instruments create? And how might these arrangements contribute to the laudable if lofty goals of steering innovation in useful directions? The paper follows two innovation instruments designed to influence innovation in the domain of robotics; the establishment of a "certified testbed" and a "co-creation facility". The paper asks how do co-creation instruments in the field of robotics steer innovation towards social progress or otherwise? Using a situated analysis method, this paper traces the two instruments in and around a single robotics innovation facility in the United Kingdom