The role of Ar III in quantitative spectroscopy on hot argon plasmas

We perform quantitative optical emission spectroscopy on the hot core of the cathode region of a free-burning arc in argon under atmospheric pressure. As the peak temperatures in the centre of the discharge exceed 22 000 K we are able to observe three spectra of argon (Ar I, Ar II and Ar III) and the continuum emission. We report on some inconsistencies concerning the evaluation of Ar III radiation in both line and continuum emission. These are caused by erroneous data in the literature and common misconceptions about the influence of Ar III on the plasma emission. We discuss the impact of this fact on published data

Virtual learning environment for interactive engagement with advanced quantum mechanics

A virtual learning environment can engage university students in the learning process in ways that the traditional lectures and lab formats can not. We present our virtual learning environment \emph{StudentResearcher} which incorporates simulations, multiple-choice quizzes, video lectures and gamification into a learning path for quantum mechanics at the advanced university level. \emph{StudentResearcher} is built upon the experiences gathered from workshops with the citizen science game Quantum Moves at the high-school and university level, where the games were used extensively to illustrate the basic concepts of quantum mechanics. The first test of this new virtual learning environment was a 2014 course in advanced quantum mechanics at Aarhus University with 47 enrolled students. We found increased learning for the students who were more active on the platform independent of their previous performances.Comment: 8 pages, 6 figure

Clinical experience with amikacin, a new aminoglycoside antibiotic

CITATION: Theron, F. P. & De Kock, M. A. 1977. Clinical experience with amikacin, a new aminoglycoside antibiotic. South African Medical Journal, 51(21):746-8.The original publication is available at http://www.samj.org.za[No abstract available]Publisher’s versio

Pulmonary Embolism Complicating Permanent Cardiac Pacing

Pulmonary embolism arising from intracardiac electrodes in permanently-paced patients, is fortunately rare. The serious nature of the complication is illustrated by a case report

State sum construction of two-dimensional open-closed Topological Quantum Field Theories

We present a state sum construction of two-dimensional extended Topological Quantum Field Theories (TQFTs), so-called open-closed TQFTs, which generalizes the state sum of Fukuma--Hosono--Kawai from triangulations of conventional two-dimensional cobordisms to those of open-closed cobordisms, i.e. smooth compact oriented 2-manifolds with corners that have a particular global structure. This construction reveals the topological interpretation of the associative algebra on which the state sum is based, as the vector space that the TQFT assigns to the unit interval. Extending the notion of a two-dimensional TQFT from cobordisms to suitable manifolds with corners therefore makes the relationship between the global description of the TQFT in terms of a functor into the category of vector spaces and the local description in terms of a state sum fully transparent. We also illustrate the state sum construction of an open-closed TQFT with a finite set of D-branes using the example of the groupoid algebra of a finite groupoid.Comment: 33 pages; LaTeX2e with xypic and pstricks macros; v2: typos correcte

Charge Influence On Mini Black Hole's Cross Section

In this work we study the electric charge effect on the cross section production of charged mini black holes (MBH) in accelerators. We analyze the charged MBH solution using the {\it fat brane} approximation in the context of the ADD model. The maximum charge-mass ratio condition for the existence of a horizon radius is discussed. We show that the electric charge causes a decrease in this radius and, consequently, in the cross section. This reduction is negligible for protons and light ions but can be important for heavy ions.Comment: 4 pages, 0 figure. To be published in Int. J. Mod. Phys. D