Hydrodynamic cavitation in micro channels with channel sizes of 100 and 750 micrometers

Decreasing the constriction size and residence time in hydrodynamic cavitation is predicted to give increased hot spot temperatures at bubble collapse and increased radical formation rate. Cavitation in a 100 x 100 mu m(2) rectangular micro channel and in a circular 750 mu m diameter milli channel has been investigated with computational fluid dynamics software and with imaging and radical production experiments. No radical production has been measured in the micro channel. This is probably because there is no spherically symmetrical collapse of the gas pockets in the channel which yield high hot spot temperatures. The potassium iodide oxidation yield in the presence of chlorohydrocarbons in the milli channel of up to 60 nM min(-1) is comparable to values reported on hydrodynamic cavitation in literature, but lower than values for ultrasonic cavitation. These small constrictions can create high apparent cavitation collapse frequencies.

Dis)Harmony in Illyria: Music, Order, and Time in Twelfth Night:Music, Order, and Time in Twelfth Night

This paper considers the integral aspect of music as performed in Shakespeare's Twelfth Night. It posits that music is that which orders and structures time in its interplay throughout the play.

Escaping From The Past? The Falkland Islands in the Twenty-First Century

This paper discusses the competing claims for the sovereignty of the Falkland Islands in the South Atlantic, which led to a war in 1982 between the United Kingdom and Argentina, which given that it was over competing claims for sovereignty over a non-independent territory seemed to be redolent of the nineteenth rather than the late-twentieth century. Post-war developments are outlined whilst the paper considers whether or not the Falkland Islands can ever escape from the Conflict, now more than thirty years ago.

Der deutsche Lebensstandard während des Ersten Weltkrieges in historischer Perspektive: Welche Rolle spielten Konsumentenpräferenzen?

After the outbreak of war in 1914 and the subsequent blockade implemented by British navy, the German economy faced serious food shortages leading to famine-like conditions, especially towards the end of the war. As a response to these shortages, the German authorities introduced and implemented socialist policies such as price ceilings and food rations. This study focuses on the inefficient use of high-quality foodstuffs by members of lower social strata by discussing consumer decisions during the First World War from a microeconomic perspective. The German rationing system provided small, but valuable – measured by black market prices – quantities of superior foodstuffs. Especially meat could have been traded on flourishing black markets for greater quantities of inferior staple foods such as bread and potatoes. In this paper I argue that a more efficient use of rations by the poor could have improved their nutritional situation.