Capillary breakup of suspensions near pinch-off

We present new findings on how the presence of particles alters the pinch-off dynamics of a liquid bridge. For moderate concentrations, suspensions initially behave as a viscous liquid with dynamics determined by the bulk viscosity of the suspension. Close to breakup, however, the filament loses its homogeneous shape and localised accelerated breakup is observed. This paper focuses on quantifying these final thinning dynamics for different sized particles with radii between 3 μm and 20 μm in a Newtonian matrix with volume fractions ranging from 0.02 to 0.40. The dynamics of these capillary breakup experiments are very well described by a one-dimensional model that correlates changes in thinning dynamics with the particle distribution in the filament. For all samples, the accelerated dynamics are initiated by increasing particle-density fluctuations that generate locally diluted zones. The onset of these concentration fluctuations is described by a transition radius, which scales with the particle radius and volume fraction. The thinning rate continues to increase and reaches a maximum when the interstitial fluid is thinning between two particle clusters. Contrary to previous experimental studies, we observe that the final thinning dynamics are dominated by a deceleration, where the interstitial fluid appears not to be disturbed by the presence of the particles. By rescaling the experimental filament profiles, it is shown that the pinching dynamics return to the self-similar scaling of a viscous Newtonian liquid bridge in the final moments preceding breakup

Shop stewards’ leadership, left-wing activism and collective workplace union organisation

Providing an account of the dynamic interrelationship between shop steward leadership and membership interaction, Ralph Darlington focuses particular attention on the much-neglected crucial role that left-wing political activists can play in shaping the nature of collective workplace relations

Invasive fungal infections in neutropenic enterocolitis: A systematic analysis of pathogens, incidence, treatment and mortality in adult patients

BACKGROUND: Neutropenic enterocolitis is a life-threatening complication most frequently occurring after intensive chemotherapy in acute leukaemias. Gramnegative bacteria constitute the most important group of causative pathogens. Fungi have also been reported, but their practical relevance remains unclear. The guidelines do not address concrete treatment recommendations for fungal neutropenic enterocolitis. METHODS: Here, we conducted a metaanalysis to answer the questions: What are frequency and mortality of fungal neutropenic enterocolitis? Do frequencies and microbiological distribution of causative fungi support empirical antimycotic therapy? Do reported results of antimycotic therapy in documented fungal neutropenic enterocolitis help with the selection of appropriate drugs? Following a systematic search, we extracted and summarised all detail data from the complete literature. RESULTS: Among 186 articles describing patients with neutropenic enterocolitis, we found 29 reports describing 53 patients with causative fungal pathogens. We found no randomised controlled trial, no good quality cohort study and no good quality case control study on the role of antifungal treatment. The pooled frequency of fungal neutropenic enterocolitis was 6.2% calculated from all 860 reported patients and 3.4% calculated from selected representative studies only. In 94% of the patients, Candida spp. were involved. The pooled mortality rate was 81.8%. Most authors did not report or perform antifungal therapy. CONCLUSION: In patients with neutropenic enterocolitis, fungal pathogens play a relevant, but secondary role compared to bacteria. Evidence concerning therapy is very poor, but epidemiological data from this study may provide helpful clues to select empiric antifungal therapy in neutropenic enterocolitis

Political Activism and Workplace industrial relations in a UK failing school

‘The definitive version is available at www.blackwell-synergy.com '. Copyright Blackwell Publishing. DOI: 10.1111/1467-8543.00263Peer reviewe

A lithological assessment of the resistivity data acquired during the airborne geophysical survey of Anglesey, North Wales

A recent airborne geophysical survey has provided high resolution estimates of the electrical resistivity of the near-surface and deeper (bedrock) formations found across Anglesey and a portion of the coastal area of North Wales. This single small survey provides new geophysical information on both the complex configuration of the Neoproterozoic and Cambrian bedrock units and the shallow near-surface geology and glacial features. The correlation between the specific rock lithologies (bedrock and sub-glacial) and the derived bulk resistivities are examined. The geological classification of the geophysical data provides an assessment of 16 lithological units and allows baseline resistivity maps at a range of investigation depths to be constructed at 1:250k scale. The study indicates a broad age-dependence with the Palaeozoic (Carboniferous) bedrock units being the most conductive formations. More detailed studies are performed using statistical departures from the norms. The data have been used to identify sub-zones, within the existing lithological classification, that define statistically distinct groupings. The study shows that the Anglesey Blueschists of the Aethwy Complex are dissimilar (displaying higher resistivities and greater dispersion) to the main schistose zones within the survey area. In the near-surface, the data map surprisingly continuous conductive and resistive zonations. Some of the conductive zones are shown to coincide with the mapped sub-glacial landforms (drumlins) deposited during the Devensian glaciations

Jetting complex fluids containing pigments and resins

We have previously studied DoD jetting of complex model fluids based on dilute polymer solutions, resulting in the identification of a new regime of polymer jetting and some basic rules for predicting the limiting polymeric concentrations under real conditions such as print head nozzle diameter, jetting speed, solvent quality and polymer molecular weights [1, 2]. There has been no systematic experimental study of the effect of particles on DoD scale jetting, despite the ground-breaking work by Furbank and Morris [3] as reported in NIP17 for the effects of particles on dripping, although theoretical modelling for liquid bridges/filaments containing particles has been recently published [4] and could be relevant to local thinning of DoD ligaments. A series of pigmented inks in the solvent dipropylene glycol methyl ether (DPM) has been used to help study effects of pigment particle size (dm = 3.6, 2.6, 1.6, 1.0, 0.8 pan) on DoD jetting. These inks contained 35 wt% of the inorganic black pigment copper chromite and had a low shear-rate viscosity of ∼ 15 mPa s. Ink characterisation used a high frequency rheometer [5] and a novel fast (5 m/s) filament stretching device [6, 7], while the DoD jetting used MicroFab 80 pan diameter nozzles [8]. Jetting experiments were performed at 100 Hz to avoid nozzle clogging. We report the first systematic experimental studies for DoD scale jets of characterized inks comprising (a) particles in DPM; (b) resin DPM; and (c) combinations of particles and resins in DPM [9, 10]. These results will provide new insights into the jetting of pigmented inks and be important for new applications