Planar Rayleigh scattering measurements using an ArF-excimerlaser have been performed to investigate helium mixing into air atsupersonic speeds. The capability of the Rayleigh scattering technique for flowvisualization of a turbulent environment is demonstrated in a large-scale, Mach 6facility. The detection limit obtained with the present setup indicates thatplanar, quantitative measurements o...

In this paper, an all-optical AND logic scheme which exploits the cross-phase modulation (XPM) effect in semiconductor-optical-amplifier-assisted Mach-Zehnder Interferometer (SOA-MZI), is proposed, performance analyzed and parameters optimized. The proposal is validated and the system performance under various parameters is examined through numerical simulations. With only moderate parameters, ...

1.1 SOAs as nonlinear elements in Mach-Zehnder Interferometers Although SOAs have been initially introduced as integrated modules mainly for optical amplification purposes, they have been widely used in all optical signal processing applications, like all-optical switching and wavelength conversion, utilizing the exhibited nonlinearities such as gain saturation, cross-gain (XGM) and cross-phase...

The majority of observations of Interplanetary Coronal Mass Ejections (ICMEs) are made with a single spacecraft and their properties inferred from a fit to a cylindrically symmetric model. This process produces a single dimension for a magnetic cloud, its radial thickness. If the radius of curvature of an ICME were equal to its half thickness, the shock front driven by the ICME would be at a di...

The development of Doppler global velocimetry is described. Emphasis is placed on the modifications necessary to advance this nonintrusive laser based measurement technique from a laboratory prototype to a viable wind tunnel flow diagnostics tool. Several example wind tunnel flow field investigations are described to illustrate the versatility of the technique. Flow conditions ranged from incom...

The behaviour of an initially planar shock wave propagating into a linearly convergent wedge is investigated experimentally and numerically. In the experiment, a 25◦ internal wedge is mounted asymmetrically in a pressure-driven shock tube. Shock waves with incident Mach numbers in the ranges of 1.4–1.6 and 2.4–2.6 are generated in nitrogen and carbon dioxide. During each run, the full pressure ...

We have developed a series of benchmark programs to test the performance of the Mach operating system. A discussion of the philosophy of the benchmarks is given, and the individual benchmark programs are described. Results of the benchmarks on 386-based machines running Mach 2.5, Mach 3.0, and SCO System V/386 are given. Appeared in: Proceedings of the USENIX Mach Workshop, 1990, 83-100.

High Mach number astrophysical jets are simulated using a positive scheme, and are compared with WENO-LF simulations. A version of the positive scheme has allowed us to simulate astrophysical jets with radiative cooling up to Mach number 270 with respect to the heavy jet gas, a factor of two times higher than the maximum Mach number attained with the WENO schemes and ten times higher than with ...

Interprocess communication (IPC) provides the fundamental mechanism for the Mach microkernel to be extensible and exible. Mach IPC provides eecient communication mechanisms for many applications. However, it does not provide suucient functionality for real-time applications which have rigid timing constraints among threads. In Real-Time Mach (RT-Mach), we have extended Mach IPC to be priority i...