Two-fluid magnetic island dynamics in slab geometry: II - Islands interacting with resistive walls or static external resonant magnetic perturbations

The dynamics of a propagating magnetic island interacting with a resistive wall or a static external magnetic perturbation is investigated using two-fluid, drift-MHD theory in slab geometry. In both cases, the island equation of motion is found to take exactly the same form as that predicted by single-fluid MHD theory. Three separate ion polarization terms are found in the Rutherford island width evolution equation. The first is the drift-MHD polarization term for an isolated island, and is completely unaffected by interaction with a wall or magnetic perturbation. Next, there is the polarization term due to interaction with a wall or magnetic perturbation which is predicted by single-fluid MHD theory. Finally, there is a hybrid of the other two polarization terms. The sign of this term depends on many factors. However, under normal conditions, it is stabilizing if the unperturbed island propagates in the ion diamagnetic direction (in the lab. frame), and destabilizing if it propagates in the electron diamagnetic direction

Support: Can it be a value creation strategy for positive marketing?

In pursuit of improving people's wellbeing and engaging in positive marketing, this paper addresses the application of Vickers' Appreciation System to deepen our understanding of how people comprehend their environment and respond to improve their situation. The paper highlights how companies can collaboratively engage in people's appreciation and support them in fulfilling their needs

Two-fluid magnetic island dynamics in slab geometry: I - Isolated islands

A set of reduced, 2-D, two-fluid, drift-MHD equations is derived. Using these equations, a complete and fully self-consistent solution is obtained for an isolated magnetic island propagating through a slab plasma with uniform but different ion and electron fluid velocities. The ion and electron fluid flow profiles around the island are uniquely determined, and are everywhere continuous. Moreover, the island phase-velocity is uniquely specified by the condition that there be zero net electromagnetic force acting on the island. Finally, the ion polarization current correction to the Rutherford island width evolution equation is evaluated, and found to be stabilizing provided that the anomalous perpendicular ion viscosity significantly exceeds the anomalous perpendicular electron viscosity

Examining Prehistoric Migration Patterns in the Palauan Archipelago: A Computer Simulated Analysis of Drift Voyaging

A number of recent genetic, linguistic, and archaeological studies have attempted to ascertain the origin of settlers to the Palauan archipelago, but it remains a complex and debated issue. To provide additional insight into colonization strategies and settlement patterns, we conducted computer simulations of drift voyages to the Palauan archipelago based on historically recorded winds and currents. Drift voyages were considered here as drifting before the wind when lost, a strategy documented for Pacific Islanders. The simulations suggest that peoples drifting before the wind from the southern Philippines would have had the most success in landfall. This finding supports the current hypothesis of human colonization to the islands of Palau. KEYWORDS: Computer simulation, drift voyaging, seafaring, colonization, Palau, Micronesia

Randomisation before consent : avoiding delay to time-critical intervention and ensuring informed consent

Peer reviewedPostprin

Postoperative complications associated with external skeletal fixators in cats

OBJECTIVES: The objective of this study was to quantify complications associated with external skeletal fixators (ESFs) in cats and to identify potential risk factors. METHODS: A retrospective review of medical records and radiographs following ESF placement was performed. RESULTS: Case records of 140 cats were reviewed; fixator-associated complications (FACs) occurred in 19% of cats. The region of ESF placement was significantly associated with complication development. Complications developed most frequently in the femur (50%), tarsus (35%) and radius/ulna (33%). Superficial pin tract infection (SPTI) and implant failure accounted for 45% and 41% of all FACs, respectively. SPTI occurred more frequently in the femur, humerus and tibia, with implant failure more frequent in the tarsus. No association between breed, age, sex, weight, fracture type (open vs closed), ESF classification, number of pins per bone segment, degree of fracture load sharing, and the incidence or type of FAC was identified. No association between region of placement, breed, age, sex, weight, fracture type (open vs closed), ESF classification, number of pins per bone segment, fracture load sharing and the time to complication development was identified. CONCLUSIONS AND RELEVANCE: Complication development is not uncommon in cats following ESF placement. The higher complication rate in the femur, tarsus and radius/ulna should be considered when reviewing options for fracture management. However, cats appear to have a lower rate of pin tract infections than dogs