Dynamic flow phenomena in a foam application unit

If, during the operation of a foam application unit, a change in the foam production is introduced, the change in the flow becomes noticeable at the point of application onlyafter a certain response delay time. During the operation of the unit it is necessary to take this response delay into consideration. By varying the flow of foam in the application unit, the mass content of foam in the unit is changed as a result of the changed pressure inside the unit. The response delay has been mathematically derived for the flow of agiven type of foam through pipes, as well as through a foam printing unit as a whole. A deviation in the yield of foam on the substrate can be avoided by considering the respons delay caused by a change in the foam production process

The flow properties of foam

The rheological behaviour of foam, prepared from an aqueous solution with lauryl sulphate as surfactant, has been measured with a viscometer as a function of the blow ratio, bubble diameter distribution and concentration of the thickener used. The influence of wall slip and of hysteresis effects on the rheological behaviour have been determined. Calculations and measurements pertaining to the pressure drop in pipes have been performed, in which the foam was considered as a compressible pseudoplastic whose rheology depended on blow ratio. The distribution of the foam passing through a closed distribution unit has been studied. This distribution unit consisted of a pipe and a cross-head distribution slit. Complementary measurements of the flow of foam through narrow slits have been made. The design of a closed foam distribution unit is discussed. The consequences of the choice of several design parameters are examined

Foam generation in a rotor—stator mixer = Schaumerzeugung in einem rotor—stator mischer

The foaming process of an aqueous liquid system with surface active agents and thickeners in a rotor-stator mixer has been studied.\ud \ud The foaming capacity of a rotor—stator mixer may be represented by a so-called mixing characteristic. The foamabilities of several liquid systems have been measured as a function of the mixer geometry and the rotational speed.\ud \ud The hydrodynamics in a rotor-stator mixer is characterized by a Newton—Reynolds relationship. The mechanism of foaming and the dependence of several mixing parameters are different for the turbulent and laminar flow regions. The mixing process is evaluated in both regimes. In the transition region from turbulent to laminar the foaming is very poor in comparison with that in the turbulent and laminar flow regimes.\u

Foam Generation in Rotor-Stator Mixers

One of the unit operations in foam technology is foam generation in a liquid/gas mixer. The foaming process of an aqueous liquid system with a surface-active agent in a rotor-stator mixer has been studied, and it was found that it could be represented by a mixing characteristic relating the liquid flow rate to the maximum gas flow rate needed to produce a foam without 'blow-by'. Too high a gas flow rate resulted in a short-circuiting flow of gas via the rotor shaft to the outlet. The influence of the number of rotor-stator blades, equipment size and operating pressure on the behaviour of the foam mixer has been investigated

New identities from remnants of the past: an examination of the history of beer brewing in Ontario and the recent emergence of craft breweries

We present an exploratory analysis of historical narratives and data covering 200 years of beer brewing in the Canadian province of Ontario. These data are used to illuminate the process of collective identity emergence in established organisational fields. We argue that established fields are typically littered with identity remnants from ancestral organisations and related institutional configurations that can facilitate the successful emergence of new collective identities. In our analysis we first show how multiple identity elements fell by the wayside as the beer brewing field matured and settled on a corporate path. We go on to detail how some of these identity elements were subsequently recovered during the recent decades which marked the successful emergence and proliferation of craft beer brewing. Our study has implications for research on collective identity and organisational legacy, and we stress the importance of taking a historical lens for understanding present day phenomena

Schottky barrier formation at amorphous-crystalline interfaces of GeSb phase change materials

The electrical properties of amorphous-crystalline interfaces in phase change materials, which are important for rewritable optical data storage and for random access memory devices, have been investigated by surface scanning potential microscopy. Analysis of GeSb systems indicates that the surface potential of the crystalline phase is similar to 30-60 mV higher than that of the amorphous phase. This potential asymmetry is explained qualitatively by the presence of a Schottky barrier at the amorphous-crystalline interface and supported also by quantitative Schottky model calculations. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3691179

The strategic use of historical narratives: a theoretical framework

History has long been recognised as a strategic and organisational resource. However, until recently, the advantage conferred by history was attributed to a firm’s ability to accumulate heterogeneous resources or develop opaque practices. In contrast, we argue that the advantage history confers on organisations is based on understanding when the knowledge of the past is referenced and the reasons why it is strategically communicated. We argue that managers package this knowledge in historical narratives to address particular organisational concerns and audiences. As well, we show that different historical narratives are produced with the goal of achieving different organisational outcomes. The success of an organisation is thus dependent on the ability of its managers to skilfully develop historical narratives that create a strategic advantage

The prescribing needs of community practitioner nurse prescribers: a qualitative investigation using the theoretical domains framework and COM-B.

With several qualified community practitioner nurse prescribers (CPNPs) not prescribing, this research aimed to understand what influences this behaviour. A qualitative research design. Semi-structured interviews, based on the theoretical domains framework (TDF) were conducted with 20 CPNPs. Data collection took place between March-July 2018 and continued until data saturation was reached. Nine themes inductively explained prescribing behaviour: 1) 'Knowledge and experience'; 2) 'Consultation and communication skills'; 3) 'Professional confidence and identity'; 4) 'Wanting the best outcome'; 5) 'NHS versus patient cost'; 6) 'Emotion-led decisions'; 7) 'Time allocation'; 8) 'Formulary access' and 9) 'Supporting environment for patient-centred care'. Themes were then deductively mapped to the TDF and COM-B. There is an ongoing need to support community practitioner nurse prescribers' 'Capability' to prescribe in terms of knowledge and aquired skills; 'Opportunity' to make prescribing easier, such as access to a wider and up to date nurse formulary alongside effective clinical support; and 'Motivation' to feel confident in prescribing behaviour, highlighting positive patient outcomes while reducing perceived issues such as cost and non-adherence. Findings show that Capability, Opportunity and Motivation all influence the decision to prescribe. Those responsible for professional regulation and training should ensure community practitioner nurse prescribers have access to the relevant knowledge, skills and formulary to facilitate their prescribing behaviour. Professional confidence and identity as a prescriber should be encouraged, with acknowledgment of influences such as cost and emotion. An environment that allows for patient-centred care and the best outcome should be supported, this may mean increasing time allocated to consultations. AIM DESIGN METHODS RESULTS CONCLUSION IMPAC