Abstract: A method is provided for generating a region of plasma in a gaseous atmosphere that includes argon. A laser beam from a Ti:sapphire laser is directed into the gaseous atmosphere such that a portion of the argon along the laser beam is ionized. Microwave energy is directed into the ionized region of the laser beam to generate a plasma.

Abstract: A method is provided for generating a region of plasma in a gaseous atmosphere that includes argon. A laser beam from a Ti:sapphire laser is directed into the gaseous atmosphere such that a portion of the argon along the laser beam is ionized. Microwave energy is directed into the ionized region of the laser beam to generate a plasma.

Abstract: An apparatus delays the transition of a boundary layer flow from laminar to turbulent. Flow disruptors are positioned to be in contact with a boundary layer flow moving in a flow direction over a surface. Each flow disruptor generates fluctuations in the boundary layer flow such that the frequency of the fluctuations is a damping region frequency defined by an amplification rate curve associated with the boundary layer flow.

Abstract: An apparatus delays the transition of a boundary layer flow from laminar to turbulent. Flow disruptors are positioned to be in contact with a boundary layer flow moving in a flow direction over a surface. Each flow disruptor generates fluctuations in the boundary layer flow such that the frequency of the fluctuations is a damping region frequency defined by an amplification rate curve associated with the boundary layer flow.

Abstract: A method and system are provided for determining temperature of a low density gas seeded with molecules of iodine. The Cordes bands of the iodine molecules are excited with light energy of a known wavelength (e.g., between 175-210 nanometers) to generate fluorescent emission. At least a portion of the emission's light intensity is collected and used to generate an emission spectrograph. The spectrograph's vibrational energy level peaks are fitted to a vibrational Boltzmann distribution. Specifically, one of the vibrational energy level peaks associated with molecule population in a ground vibrational energy level at a wavelength greater than the known wavelength of the light energy is selected. Next, a plurality of ratios are generated that define a unique linear relationship for a temperature of the seeded environment.

Abstract: A method and system are provided for determining temperature of a low density gas seeded with molecules of iodine. The Cordes bands of the iodine molecules are excited with light energy of a known wavelength (e.g., between 175-210 nanometers) to generate fluorescent emission. At least a portion of the emission's light intensity is collected and used to generate an emission spectrograph. The spectrograph's vibrational energy level peaks are fitted to a vibrational Boltzmann distribution. Specifically, one of the vibrational energy level peaks associated with molecule population in a ground vibrational energy level at a wavelength greater than the known wavelength of the light energy is selected. Next, a plurality of ratios are generated that define a unique linear relationship for a temperature of the seeded environment.

Abstract: Method and apparatus unaffected by vibrational environments for obtaining measurements using Raman Doppler Velocimetry. Two laser beams, a pump beam 18 and a probe beam 22, are focused by a lens 21 to a point 25 in a flow 11. A lens 26 collimates the two beams. A beam splitter 27 dumps beam 18 and beam 22 is reflected by a corner cube 28 back to lens 26. Lens 26 then focuses the beam back to point 25. The reflected beam 22 and the backward and forward scattering at point 25 are detected by a detector 30 and processed by a boxcar averager 31. The lens 26 and corner cube 28 combination, called a retrometer 29, ensure that the measurements are unaffected by vibrations.

Abstract: An apparatus is disclosed for monitoring the development and growth of fatigue cracks in a test specimen subjected to a pulsating tensile load. A plurality of television cameras photograph a test specimen which is illuminated at the point of maximum tensile stress. The television cameras have a modified vidicon tube which has an increased persistence time thereby eliminating flicker in the displayed images.

Abstract: This invention is method and apparatus for measuring, at a remote location, the concentration and velocity of SO.sub.2 in plume from a smokestack. An ultraviolet video system views the plume against the background sky at wavelengths where SO.sub.2 molecules absorb light. The result is a real time display of the plume coupled with means for measuring the SO.sub.2 concentration at any point in the plume and at any time desired. In addition, means are provided in combination with the ultraviolet video system for measuring the velocity of the SO.sub.2 in the plume.