The use of arc-suppression coils in power systems with open-delta regulators

Arc-suppression coil systems are able to improve high voltage system reliability and safety. If these systems are used in high voltage power distribution networks which incorporate open-delta regulators, dangerous over-voltages can occur. Because the open-delta regulators increase the line to earth voltage in two phases only, out of balance line to earth capacitance currents flow through the arc-suppression coil. It is shown that under certain conditions the resultant system voltages can reach dangerous levels. It is recommended that a detailed analysis be carried out before arc-suppression coils and open-delta regulators are installed in the same power system

T700 power turbine rotor multiplane/multispeed balancing demonstration

Research was conducted to demonstrate the ability of influence coefficient based multispeed balancing to control rotor vibration through bending criticals. Rotor dynamic analyses were conducted of the General Electric T700 power turbine rotor. The information was used to generate expected rotor behavior for optimal considerations in designing a balance rig and a balance technique. The rotor was successfully balanced 9500 rpm. Uncontrollable coupling behavior prevented observations through the 16,000 rpm service speed. The balance technique is practical and with additional refinement it can meet production standards

The Free Energy of N=4 Super-Yang-Mills and the AdS/CFT Correspondence

We compute the high-temperature limit of the free energy for four-dimensional N=4 supersymmetric SU(N_c) Yang-Mills theory. At weak coupling we do so for a general ultrastatic background spacetime, and in the presence of slowly-varying background gauge fields. Using Maldacena's conjectured duality, we calculate the strong-coupling large-N_c expression for the special case that the three-space has constant curvature. We compare the two results paying particular attention to curvature corrections to the leading order expressions.Comment: 26 pages.Minor corrections to eqs.(19),(21). Results and conclusions unchanged. References adde

Searching for the dual of the Maxwell-Chern-Simons model minimally coupled to dynamical U(1) charged matter

The possibility of dual equivalence between the self-dual and the Maxwell-Chern-Simons (MCS) models when the latter is coupled to dynamical, U(1) fermionic charged matter is examined. The proper coupling in the self-dual model is then disclosed using the iterative gauge embedding approach. We found that the self-dual potential needs to couple directly to the Chern-Kernel of the source in order to establish this equivalence besides the need for a self-interaction term to render the matter sector unchanged.Comment: 4 pages, RevTeX, new references, accepted for publication on Phys. Lett.

Singer-Songwriter meets Music Production and Studio Technology

Almost every singer-songwriter who aspires to make a living from their craft will be involved in the music recording and production process at some point in their career. Recorded music allows a musician to be able to promote their material remotely, opening up the opportunity of reaching a huge global audience. Recorded music also serves the reflective songwriting process itself and allows an artist to seek professional opportunities and showcase their capabilities to labels, managers and publishers. For professional artists, record production is a gateway to income and success that immediately adds the possibility of new revenue streams. This chapter focuses on the music production process and a number of related aspects that a professional singer-songwriter can expect to encounter during their career. In particular, core studio production technologies are discussed, as well as opportunities to use music production techniques as an expanded toolset for songwriting itself. The concept of working with a specialist music producer is introduced, alongside common challenges of the recording process, such as critical appraisal and a quest for sonic perfection. Finally, the avenues for using recorded music as a core revenue stream for singer-songwriters are considered, in order to provide a framework for achieving sustainable success as a songwriter and recording artist