Reynolds Number Effects on Fully-Developed Pulsed Jets Impinging on Flat Surfaces

A systematic study of the effect of the Reynolds number on the fluid dynamics and turbulence statistics of pulsed jets impinging on a flat surface is presented. It has been suggested that the influence of the Reynolds number may be somewhat different for a jet subjected to pulsation when compared to an equivalent steady jet. A comparative study of both steady and pulsating jets is presented for a Reynolds number range from Re = 4;730 to Re = 10;000. All the other factors that affect the flowfield are kept constant, which are H/d = 3, St = 0.25, and d = 30.5 mm. It was found that for the range of the Reynolds numbers tested, pulsation results in a shortening of the jet core, the centerline axial velocity component declines more rapidly, and higher values of the radial velocity component for r/d > 0.75are observed. As the Reynolds number increases, the jet spreads more rapidly, the turbulent kinetic energy and nondimensional turbulent fluctuations decrease, and the flowfield near the impinging surface changes drastically, which is evident with the development of a turbulent momentum exchange interaction away from the wall for r/d > 1.5.

Pressure drop of gas–liquid Taylor flow in round micro-capillaries for low to intermediate Reynolds numbers

In this paper, a model is presented that describes the pressure drop of gas-liquid Taylor flow in round capillaries with a channel diameter typically less than 1 mm. The analysis of Bretherton (J Fluid Mech 10:166-188, 1961) for the pressure drop over a single gas bubble for vanishing liquid film thickness is extended to include a non-negligible liquid film thickness using the analysis of Aussillous and Qu,r, (Phys Fluids 12(10):2367-2371, 2000). This result is combined with the Hagen-Poiseuille equation for liquid flow using a mass balance-based Taylor flow model previously developed by the authors (Warnier et al. in Chem Eng J 135S:S153-S158, 2007). The model presented in this paper includes the effect of the liquid slug length on the pressure drop similar to the model of Kreutzer et al. (AIChE J 51(9):2428-2440, 2005). Additionally, the gas bubble velocity is taken into account, thereby increasing the accuracy of the pressure drop predictions compared to those of the model of Kreutzer et al. Experimental data were obtained for nitrogen-water Taylor flow in a round glass channel with an inner diameter of 250 mu m. The capillary number Ca (gl) varied between 2.3 x 10(-3) and 8.8 x 10(-3) and the Reynolds number Re (gl) varied between 41 and 159. The presented model describes the experimental results with an accuracy of +/- 4% of the measured values.

Seven new loci associated with age-related macular degeneration

Age-related macular degeneration (AMD) is a common cause of blindness in older individuals. To accelerate the understanding of AMD biology and help design new therapies, we executed a collaborative genome-wide association study, including >17,100 advanced AMD cases and >60,000 controls of European and Asian ancestry. We identified 19 loci associated at P <5 × 10(-8). These loci show enrichment for genes involved in the regulation of complement activity, lipid metabolism, extracellular matrix remodeling and angiogenesis. Our results include seven loci with associations reaching P <5 × 10(-8) for the first time, near the genes COL8A1-FILIP1L, IER3-DDR1, SLC16A8, TGFBR1, RAD51B, ADAMTS9 and B3GALTL. A genetic risk score combining SNP genotypes from all loci showed similar ability to distinguish cases and controls in all samples examined. Our findings provide new directions for biological, genetic and therapeutic studies of AMD.

From Frank Miller to Zack Snyder, and Return: Contemporary Superhero Comics and Post-Classical Hollywood

Film adaptations of superhero comic-books offer a particularly rich case study to analyse narrative strategies of contemporary Hollywood cinema. The serial structures adopted by the comics they are based on, as well as their use of the spectacular potential of the image, provide a successful model for current audiovisual productions. Without completely abandoning classical techniques, these adaptations try to find a new balance between narrative and digital phantasmagoria. This paper discusses some significant examples of this genre, including adaptations of classical DC and Marvel franchises and more recent series, as well as other comic-book influenced films such as The Matrix and Unbreakable.

'Frank Pig Says Hello' by Pat McCabe

This theatre performance, produced in association with An Grianan Theatre, Letterkenny, contributes to two strands of research: theatre and mental health and Irish Physical Theatre in the 1990s.

Accumulation of the PX domain mutant Frank-ter Haar syndrome protein Tks4 in aggresomes

BACKGROUND: Cells deploy quality control mechanisms to remove damaged or misfolded proteins. Recently, we have reported that a mutation (R43W) in the Frank-ter Haar syndrome protein Tks4 resulted in aberrant intracellular localization.

RESULTS: Here we demonstrate that the accumulation of Tks4(R43W) depends on the intact microtubule network. Detergent-insoluble Tks4 mutant colocalizes with the centrosome and its aggregate is encaged by the intermediate filament protein vimentin. Both the microtubule inhibitor nocodazole and the histone deacetylase inhibitor Trichostatin A inhibit markedly the aggresome formation in cells expressing Tks4(R43W). Finally, pretreatment of cells with the proteasome inhibitor MG132 markedly increases the level of aggresomes formed by Tks4(R43W). Furthermore, two additional mutant Tks4 proteins (Tks4(1-48) or Tks4(1-341)) have been investigated. Whereas the shorter Tks4 mutant, Tks4(1-48), shows no expression at all, the longer Tks4 truncation mutant accumulates in the nuclei of the cells.

CONCLUSIONS: Our results suggest that misfolded Frank-ter Haar syndrome protein Tks4(R43W) is transported via the microtubule system to the aggresomes. Lack of expression of Tks4(1-48) or aberrant intracellular expressions of Tks4(R43W) and Tks4(1-341) strongly suggest that these mutations result in dysfunctional proteins which are not capable of operating properly, leading to the development of FTHS.

Identification of Dynamics of Surface Suction Over an Airfoil at Low Reynolds Numbers

This paper deals with identification of dynamics in suction control of airfoils for low Reynolds number regimes (8 x 10^4 - 5 x 10^5). In particular, the dynamics of interest is the map that relates suction pressure and surface pressure. Identification of such dynamics is of use to a variety of active control applications including suction control in small/medium wind turbines which operate in these Reynolds number regimes. Prior research has largely focused on higher Reynolds number regimes, creating a need for such a study. Towards identifying the said dynamic relations, experiments were conducted on NACA0012 airfoil in a wind tunnel. The dynamic relation between suction and surface pressure was identified as an overdamped second order system.

‘Twenty-six things at once’: Pragmatic perspectives on Frank O’Hara and Norman Bluhm’s Poem-Paintings

Created over a couple of Sunday mornings in the Fall of 1960, the twenty-six collaborative Poem-Paintings of the artist Norman Bluhm and the poet Frank O'Hara represent what Bluhm later called a spontaneous 'conversation' between the painter and the poet. In this essay, Catherine Gander adopts a number of pragmatist positions to reconsider these overlooked works as essential examples of verbal-visual interaction that extend their 'conversation' to greet and involve us in a relationship that is at once interpersonal, integrated, and embodied. The works, Gander argues, constitute what John Dewey terms 'art as experience'; in their back and forth exchange of verbal and visual gesture, abstraction and denotation, the Poem-Paintings are the 'cumulative continuity' of 'the process of living', dramatising the shifting, spontaneous and multiple dimensions of interpersonal conversation, and in so doing, indicating a new path toward interconnective and equal exchange between word and image.

Truth at 24 frames a second? A working dialogue between a film-maker and a historical consultant about the making of The Enigma of Frank Ryan

We employ a practice-based methodology based on a ‘live’ film project to explore the different ways that film-makers and historians narrate the past. Through a case-study of the production and exhibition of a drama-documentary feature-film, The Enigma of Frank Ryan, on which both authors (film-maker Bell and historian McGarry) worked respectively as director and historical consultant, we explore a range of critical issues arising from our collaboration. Through a dialogue between a director and a historian, a model of good practice between historians and film-makers emerges.

M. Frank Polk [sous-secrétaire d'Etat aux Affaires étrangères des États-Unis] (Central News, New York) : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 58548