FLIGHT-DETERMINED STABILITY AND CONTROL DERIVATIVES OF A SUPERSONIC AIRPLANE WITH A LOW-ASPECT-RATIO UNSWEPT WING AND A TEE-TAIL

Flight-determined stability & control derivatives of supersonic aircraft with low aspect ratio unswept wing & t-tai

Summary of XB-70 airplane cockpit environmental data

Thermal, acoustical, and acceleration environments of XB-70 airplane crew compartment in airworthiness test

qq-Trinomial identities

We obtain connection coefficients between $q$-binomial and $q$-trinomial coefficients. Using these, one can transform $q$-binomial identities into a $q$-trinomial identities and back again. To demonstrate the usefulness of this procedure we rederive some known trinomial identities related to partition theory and prove many of the conjectures of Berkovich, McCoy and Pearce, which have recently arisen in their study of the $\phi_{2,1}$ and $\phi_{1,5}$ perturbations of minimal conformal field theory.Comment: 21 pages, AMSLate

Tunable coupling to a mechanical oscillator circuit using a coherent feedback network

We demonstrate a fully cryogenic microwave feedback network composed of modular superconducting devices connected by transmission lines and designed to control a mechanical oscillator coupled to one of the devices. The network features an electromechanical device and a tunable controller that coherently receives, processes and feeds back continuous microwave signals that modify the dynamics and readout of the mechanical state. While previous electromechanical systems represent some compromise between efficient control and efficient readout of the mechanical state, as set by the electromagnetic decay rate, the tunable controller produces a closed-loop network that can be dynamically and continuously tuned between both extremes much faster than the mechanical response time. We demonstrate that the microwave decay rate may be modulated by at least a factor of 10 at a rate greater than $10^4$ times the mechanical response rate. The system is easy to build and suggests that some useful functions may arise most naturally at the network-level of modular, quantum electromagnetic devices.Comment: 11 pages, 6 figures, final published versio

Recent innovations in UHPLC columns and instrumentation

AbstractTen years after the introduction of the first commercial ultra-high-performance liquid chromatography (UHPLC) system, the pace of progress has not slowed. We describe recent innovations in UHPLC columns and instruments, focusing on those intended primarily for reversed-phase separations of analytes with molecular weights less than about 5000 Daltons, using columns with internal diameters of 2.1 mm. New columns packed with sub-2-µm solid-core particles have produced efficiencies greater than 400,000 plates/m, more than 40% higher than those of columns packed with sub-2-µm fully porous particles. In addition, columns containing charged surface particles give higher peak capacities for separations of positively charged analytes when using the low ionic strength, acidic mobile phases preferred for electrospray mass spectrometric detection. The narrow peaks produced by these columns require instruments having extremely low dispersion. We review recent progress in measuring and reducing system dispersion