Motion studies of high current arcs using an optical fibre array imaging system

This paper presents an integrated portable measurement system for thestudy of high speed and high temperature unsteady plasma flows such as thosefound in the vicinity of high current switching arcs. The system permits direct andnon-intrusive measurement of arc light emission images with a capture rate of 1million images per second (1MHz), and 8 bit intensity resolution. Novel softwaretechniques are reported to measure arc trajectories. Results are presented on singlehigh current (2kA) discharge events where the electrode and arc runner surfaces areinvestigated using 3D laser scanning methods; such that the position of the arc rootson the runner can be correlated to the measured trajectories. The results showevidence of the cathode arc root stepping along the arc runners<br/

Motion studies of high current arcs using an optical fibre array imaging system

This paper presents an integrated portable measurement system for thestudy of high speed and high temperature unsteady plasma flows such as thosefound in the vicinity of high current switching arcs. The system permits direct andnon-intrusive measurement of arc light emission images with a capture rate of 1million images per second (1MHz), and 8 bit intensity resolution. Novel softwaretechniques are reported to measure arc trajectories. Results are presented on singlehigh current (2kA) discharge events where the electrode and arc runner surfaces areinvestigated using 3D laser scanning methods; such that the position of the arc rootson the runner can be correlated to the measured trajectories. The results showevidence of the cathode arc root stepping along the arc runners<br/

Motion studies of cathode roots in high current arcs using an optical fibre array based imaging system

This paper presents an integrated portable measurement system for the study of high speed and high temperature unsteady plasma flows such as those found in the vicinity of high current switching arcs. The system permits direct and non-intrusive measurement of arc light emission images with a capture rate of 1 million images per second (1MHz), and 8 bit intensity resolution. Novel software techniques are reported to measure arc trajectories. Results are presented on single high current (2kA) discharge events where the electrode and arc runner surfaces are investigated using 3D laser scanning methods; such that the position of the arc roots on the runner can be correlated to the measured trajectories. The results show evidence of the cathode arc root stepping along the arc runners, and regions of where the arc runner is eroded by a stationary arc

Book Review of Neither Plain Nor Simple: New Perspectives on the Canterbury Shakers , by David R. Starbuck, 2004, University Press of New England, Lebanon, New Hampshire, 190 pages, 174 illustrations, $29.95 (paper).

A review of David R. Starbuck\u27s book which details his archaeological work of the Shaker people at Canterbury, near Concord, New Hampshire

Ramp Exhibition 4x3 Poster Project

4×3 is an exhibition, a memory-bank, and a game. Conceived and organised by Xavier Meade and John Mandelberg, this project draws on the personal poster archives of four artist/designers who have been active in creating and collecting politically inspired posters during the past four decades: Chris McBride (Auckland), John Mandelberg (Hamilton), John Phillips (LondonPrintStudio) and Xavier Meade (Raglan). With an initial set of three posters being put forward from their personal archives – the collaboration heats up when each artist responds to these initial works by proposing another poster that they feel in some way comments upon, or reflects the choices made by the others. This dialogue was completed when the final 48 posters were collated. 4×3, is the outcome of an enjoyable, intercontinental, time-travelling escapade, which was described by the artists’ as feeling at times as close to a game of poker, as it did an act of collaborative curation. Join the artists in the gallery at 4pm, prior to the opening preview, for a discussion about this projec

4x3 poster project

4x3 is an exhibition, a memory bank, and a game. Conceived and organised by Xavier Meade and John Mandelberg, this project draws on the personal archives of four artist/designers who have been active in creating and collecting politically inspired posters during the past four decades: Chris McBride (Auckland), John Mandelberg (Hamilton), John Phillips (London) and Xavier Meade (Raglan). Our personal archives became both the subject, and content, of the game and the exhibition, first launched at Ramp Gallery, Hamilton, 2014. The exhibition consists of 48 posters of different dimensions and techniques as indicated in the poster/catalogue including a description of the project by John Phillip

Characterization of two putative potassium channels in Plasmodium falciparum

<p>Abstract</p> <p>Background</p> <p>Potassium channels are essential for cell survival and participate in the regulation of cell membrane potential and electrochemical gradients. During its lifecycle, <it>Plasmodium falciparum </it>parasites must successfully traverse widely diverse environmental milieus, in which K⁺channel function is likely to be critical. Dramatically differing conditions will be presented to the parasite in the mosquito mid-gut, red blood cell (RBC) cytosol and the human circulatory system.</p> <p>Methods</p> <p><it>In silico </it>sequence analyses identified two open-reading frames in the <it>P. falciparum </it>genome that are predicted to encode for proteins with high homology to K⁺channels. To further analyse these putative channels, specific antisera were generated and used in immunoblot and immunofluorescence analyses of <it>P. falciparum</it>-infected RBCs. Recombinant genome methods in cultured <it>P. falciparum </it>were used to create genetic knock outs of each K⁺channel gene to asses the importance of their expression.</p> <p>Results</p> <p>Immunoblot and IFA analyses confirmed the expression of the two putative <it>P. falciparum </it>K⁺channels (PfK1 and PfK2). PfK1 is expressed in all asexual stage parasites, predominantly in late stages and localizes to the RBC membrane. Conversely, PfK2 is predominantly expressed in late schizont and merozoite stage parasites and remains primarily localized to the parasite. Repeated attempts to knockout PfK1 and PfK2 expression by targeted gene disruption proved unsuccessful despite evidence of recombinant gene integration, indicating that <it>pfk1 </it>and <it>pfk2 </it>are apparently refractory to genetic disruption.</p> <p>Conclusion</p> <p>Putative K⁺channel proteins PfK1 and PfK2 are expressed in cultured <it>P. falciparum </it>parasites with differing spatial and temporal patterns. Eventual functional characterization of these channels may reveal future pharmacological targets.</p