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Kilo Hōkū VR (t: "to observe and study the stars") is a virtual reality simulation of the Hōkūleʻa, a Polynesian double-hulled sailing canoe, and a simulation of the practice of Modern Hawaiian wayfinding, or non-instrument open ocean navigation. It was developed to assist in the cultural preservation of the celestial navigation portion of Modern Hawaiian wayfinding, and to expand the availability of learning opportunities. We here introduce new features added to the simulation for teacher and student interaction and learning. We performed a user study and observed the potential viability of using Kilo Hōkū VR with students who are currently learning wayfinding in a classroom setting.

An experiment conducted with a megajoule class helical flux compression generator (HFCG), operating into a primarily inductive load, is described. The motivation behind the experiment was to benchmark the performance of the generator at higher currents and voltages than were tested in prior experiments. The intention was to push operation into a regime where flux loss was likely to become nonlinear, thereby gaining some insight into performance limitations of the design. Another goal was the desire to benchmark the suite of computational tools used to predict the performance of the design, especially in regimes of nonlinear flux loss. In the experiment, the HFCG was seeded with 105 kA (1.05 Wb), and produced 8.6 MA (0.28 Wb) into the load. This result differed significantly from computational models of the experiment, which predicted greater than 10 MA into the load. While more than one source of flux loss was observed in the waveforms, the dominant source of loss appears to be associated with joule heating and magnetic diffusion, which were found to have the most impact during the latter stages of HFCG operation. Details of the experiment design, setup and execution will be given. Analysis of the captured data, along with comparison of these data with model predictions and past experimental data, will be shown.

Summary form only given. The University of Missouri-Columbia has recently been studying methods of generating large volume high density toroidal air plasmas. Stable, large volume high density plasma discharges in air at atmospheric pressure are difficult to achieve due to electron recombination, diffusion, and attachment as well as the high number of neutral particle collisions. In order to achieve steady state, the plasma must satisfy the continuity equation where electron generation must equal electron loss rates. This can be achieved with or without electron generation from an external source.

A multi-millisecond duration, toroidal air plasma with electron density of 1014-1015 cm-3 has been developed at the University of Missouri-Columbia. An exploding wire is used to first form the plasma and a secondary discharge region is used to further heat and impart momentum. Using this method of post discharge heating, we have been able to produce a self-confined, self-stabilized, toroidal air plasma, or TAP. A study of circuit parameters has been conducted to better understand the critical factors in the formation and evolution of the TAP. Circuit inductance and load resistance has been varied to determine the critical aspects of the formation of the TAP. A full diagnostic suite of pressure sensors, high speed photography, as well as current and voltage measurements, have been utilized to observe the TAP. Results from these experiments are presented as well as the experimental set up including the high voltage driving circuit.

The University of Missouri-Columbia Center for Physical and Power Electronics has implemented the use of exploding wires to trigger the diaphragm in a 20.3 cm diameter PVC shock tube. The shock tube is partitioned into two segments: the driver side and the driven side. The high pressure driver side is partitioned from the low pressure side by a 0.127 mm thick Mylar sheet with an exploding wire attached to it. The shock wave is generated in the tube by pressurizing the driver side of the shock tube to 30.5 psig and discharging the energy from an 11uF capacitor bank into a 30 AWG copper wire. The 9.8 cm long wire vaporizes as 4.95 kJ of stored energy is discharged into it at a peak current of 3 kA. The wire, which is attached to the Mylar, behaves like a fuse; puncturing the Mylar diaphragm as it vaporizes. This catastrophic failure results in the low jitter generation of a shock wave whereby experiments can be timed to the arrival of the shock wave. The key benefit to minimizing the jitter of shock-wave generation allows for better timing for shock-wave diagnostics and functionality. Through experimentation, shock-wave jitter times of approximately 32 µs have been observed. This jitter provides sufficient timing capabilities to efficiently capture data, as well as synchronize external events designed to interact with the shock wave. The diagnostic suite used to analyze the characteristics of the shock wave and the exploding wire includes: a schlieren setup, a phantom V7.3 high speed camera, Kistler 603B1 pressure transducers, a Tektronix TDS2024C oscilloscope, a Northstar PVM-6 high voltage probe, and a Stangenes SI-5009 current probe. The characteristics of the shock tube, as well as the exploding wire for these experiments, are reported.

A multi-millisecond duration, exploding wire air plasma with electron density of at least 1014–1015 /cm3 has been developed. Confining the radial expansion of an exploding wire discharge has resulted in interesting hydrodynamic effects, producing a toroidal air plasma, or TAP.

The Center for Physical and Power Electronics at The University of Missouri-Columbia and Applied Research Associates have recently developed an experimental test stand for the purposes of studying the interaction of shock waves with plasmas in air. The test stand includes a robust 20 cm diameter pneumatic shock tube capable of producing a consistent shock wave. Concurrently, an atmospheric-air plasma is produced to interact with the wave front produced by the shock tube. The shock wave is formed by rupturing a Mylar film diaphragm separating the pressurized driver section from the unpressurized driven section of the tube. For temporal reproducibility, an exploding wire is used to rupture the diaphragm.

Glow discharges are known to have relatively high electron densities even while maintaining stability. Applications of these discharges are numerous and include plasma reflectors and absorbers of electromagnetic radiation, surface treatment, thin film deposition and gas lasers.

The increasing demand for clean drinking water has significantly intensified the need for long lifetime, inexpensive water sterilization systems. With bottled water increasing in popularity, purity regulations need to be reconsidered. Contrary to popular opinion bottled water can contain high concentrations of bacteria; this concern must be addressed. Magnetic pulse compressors for PEF applications are a possible solution, due to their notably high lifetime, compact size, reliability and repetition-rates. The application of these systems for the purification of water needs to be explored further. The use of the short duration electrical pulses from the magnetic pulse compressor for inactivation of bacteria (Pseudomonas aeruginosa) in drinking water is being investigated at the University of Missouri-Columbia. This contaminant is considered extremely pathogenic under the right circumstances, making the increase in demand for unregulated bottled water a growing cause for concern. Coupled with the demand for clean drinking water, inexpensive water treatment systems based on high rep- rate magnetic pulse compression technology could play a significant role in point of use systems. The test cell used in this study allows static and flowing tests for pulse widths of 100-500 ns. The viability of the bacteria after treatment is assayed after a specific number of pulses are applied. The protocols, restrictions, and test data for this study are presented.