Subtleties of witnessing quantum coherence in non-isolated systems

Identifying non-classicality unambiguously and inexpensively is a long-standing open challenge in physics. The No-Signalling-In-Time protocol was developed as an experimental test for macroscopic realism, and serves as a witness of quantum coherence in isolated quantum systems by comparing the quantum state to its completely dephased counterpart. We show that it provides a lower bound on a certain resource-theoretic coherence monotone. We go on to generalise the protocol to the case where the system of interest is coupled to an environment. Depending on the manner of the generalisation, the resulting witness either reports on system coherence alone, or on a disjunction of system coherence with either (i) the existence of non-classical system-environment correlations or (ii) non-negligible dynamics in the environment. These are distinct failure modes of the Born approximation in non-isolated systems.Comment: 16pp, 2 figs, 5 thms. v2: typos corrected, references added and small change to title to reflect that of published versio

Computation of aircraft component flow fields at transonic Mach numbers using a three-dimensional Navier-Stokes algorithm

A computer analysis was developed for calculating steady (or unsteady) three-dimensional aircraft component flow fields. This algorithm, called ENS3D, can compute the flow field for the following configurations: diffuser duct/thrust nozzle, isolated wing, isolated fuselage, wing/fuselage with or without integrated inlet and exhaust, nacelle/inlet, nacelle (fuselage) afterbody/exhaust jet, complete transport engine installation, and multicomponent configurations using zonal grid generation technique. Solutions can be obtained for subsonic, transonic, or hypersonic freestream speeds. The algorithm can solve either the Euler equations for inviscid flow, the thin shear layer Navier-Stokes equations for viscous flow, or the full Navier-Stokes equations for viscous flow. The flow field solution is determined on a body-fitted computational grid. A fully-implicit alternating direction implicit method is employed for the solution of the finite difference equations. For viscous computations, either a two layer eddy-viscosity turbulence model or the k-epsilon two equation transport model can be used to achieve mathematical closure

The average X-ray/gamma-ray spectrum of radio-quiet Seyfert 1s

We have obtained the average 1--500 keV spectrum of radio-quiet Seyfert 1s using data from EXOSAT, Ginga, HEAO, and GRO/OSSE. The spectral fit to the combined average EXOSAT and OSSE data is fully consistent with that for Ginga and OSSE, confirming results from an earlier Ginga/OSSE sample. The average spectrum is well-fitted by a power-law X-ray continuum with an energy spectral index of $\alpha \simeq 0.9$ moderately absorbed by an ionized medium and with a Compton reflection component. A high-energy cutoff (or a break) in the the power-law component at a few hundred keV or more is required by the data. We also show that the corresponding average spectrum from HEAO A1 and A4 is fully compatible with that obtained from EXOSAT, Ginga and OSSE. These results confirm that the apparent discrepancy between the results of Ginga (with $\alpha \simeq 0.9$) and the previous results of EXOSAT and HEAO (with $\alpha \simeq 0.7$) is indeed due to ionized absorption and Compton reflection first taken into account for Ginga but not for the previous missions. Also, our results confirm that the Seyfert-1 spectra are on average cut off in gamma-rays at energies of at least a few hundred keV, not at $\sim 40$ keV (as suggested earlier by OSSE data alone). The average spectrum is compatible with emission from either an optically-thin relativistic thermal plasma in a disk corona, or with a nonthermal plasma with a power-law injection of relativistic electrons.Comment: 7 pages, 3 Postscript figures, MNRAS accepte

Timing Carbohydrate Beverage Intake During Prolonged Moderate Intensity Exercise Does Not Affect Cycling Performance

Carbohydrate beverages consumed during long-term exercise have been shown to attenuate fatigue and improve performance; however, the optimal timing of ingestion is unclear. Therefore, the purpose of this study was to determine if timing the carbohydrate ingestion (front-loading (FL), continual loading (CL), and end-loading (EL)) during prolonged exercise influenced exercise performance in competitive cyclists. Ten well-trained cyclists completed three separate exercise bouts on a bicycle ergometer, each lasting 2 hours at an intensity of ~67% VO2 max, followed by a 15-minute “all out” time trial. In the FL trial, participants ingested a carbohydrate beverage during the first hour and a placebo beverage during the second hour. In the CL trial, a carbohydrate beverage was ingested throughout the trial. In the EL trial, a carbohydrate beverage was ingested during the second hour and a placebo during the first hour. The amount of carbohydrate consumed (75 g) was the same among conditions. The order of conditions was single-blinded, counterbalanced, and determined randomly. Performance was measured by the work output during the 15-minute performance ride. There were no differences in work output among the three conditions during the final time trial. In the first hour of exercise, peak venous blood glucose was highest in the FL condition. In the second hour, peak venous blood glucose was highest in the EL condition. Following the time trial, venous blood glucose levels were similar among FL, CL, and EL. Overall, the timing of carbohydrate beverage consumption during prolonged moderate intensity cycling did not alter cycling performance

Harvester Guidance Control System

A guidance control system for a harvester or like machinery includes a steering linkage operatively connected to at least one ground engaging wheel. Harvester steering is controlled through the linkage by either an operator controlled steering wheel or a sensor responsive self-steering mechanism. The sensor responsive self-steering mechanism includes a guide assembly pivotally mounted to the harvester. The guide assembly includes a pair of laterally spaced, cooperating tines that define a path therebetween for plants being harvested. A sensor positioned on each tine senses the position of plants as they are harvested. A control circuit is responsive to the sensors to selectively impart movement to the steering linkage to self-steer the harvester. The control circuit includes a main valve controlled by the operator controlled steering wheel and a secondary valve controlled by the sensors. An auxiliary feed line leads from the main valve to the secondary valve. When the operator utilizes the steering wheel control, an interrupter blocks hydraulic flow through the auxiliary line from the main valve to the secondary valve. Thus, operator controlled steering input overrides the sensor responsive self-steering for maximum safety. The guidance control system also eliminates harvester wander back and forth across a row by substantially preventing overcompensation by the sensor responsive self-steering

Discount Points, Effective Yields and Mortgage Prepayments

This study addresses the perceived rankings of real estate publications and their impact in meeting the tenure requirements at AACSB member school. Roughly half of the respondents in the sample studied are AACSB accredited. The results indicate that the rank ordering of publications in the sample are consistent between the accredited and non-accredited schools, although accredited schools demonstrate systematically lower point ratings for each publication and require more points for tenure.