Thomas Z. Moore

Experimental and computed results investigating time-dependent failure in a borosilicate glass

Symmetric plate-impact tests of borosilicate glass were performed from low (116 m/s) to higher (351 m/s) velocities. The tests were recorded with an ultra-high-speed camera to see the shock and failure propagation. The velocity of the back of the target was also recorded with a PDV (Photon Doppler Velocimeter). The images show failure nucleation sites that trail the shock wave. Interestingly, even though the failure wave is clearly seen, the PDV never detected the expected recompression wave. The reason might be that at these low impact velocities the recompression wave is too small to be seen and is lost in the noise. This work also presents a new way to interpret the signals from the PDV. By letting part of the signal travel through the target and reflect on the impact side, it is possible to see the PDV decrease in intensity with time, probably due to the damage growth behind the shock wave.

A new technique for monitoring inhomogeneous deformation during flyer plate impact

A new and unique experimental configuration was developed and demonstrated to measure the inhomogeneous deformation of heterogeneous materials during flyer plate impact tests. Flyer plate experiments were performed on a granite material with a small scale structure; strain rates ranged from 105 to 107 s−1. A cross section of an impacted target was monitored and photographed during, and immediately following, passage of the shock wave through the material. Up to fourteen images were taken during passage of the shock wave. This was accomplished using an ultra-high speed Imacon camera with very short exposure times; for example, in one experiment the exposure time was 5 nanoseconds with a framing rate of 5 million frames per second. Continuous wave lasers were used as the illumination source. Edge and notch filters were used to lessen the intensity of the impact flash in the image. The photographic data was analyzed using a digital image correlation (DIC) system. These experiments examined inhomogeneous defo...

Generating multiple wavelengths, simultaneously, in a Ti:sapphire ring laser with a ramp-hold-fire seeding technique

The ability to simultaneously produce pulsed laser output over multiple discrete wavelengths can mitigate many of the timing and jitter issues associated with the use of multiple laser systems. In addition, Fourier-transform limited laser output on every pulse is required for many applications such as with pump-probe detection, non-linear frequency mixing, differential absorption lidar (DIAL), and resonance ionization. As a matter of practice, such lasers need to be capable of operating within uncontrolled or noisy environments. We report on a novel Ti:sapphire ring laser that has been developed to produce Fourier-transform limited 20-ns laser pulses at multiple discrete wavelengths, simultaneously, utilizing a Ramp-Hold-Fire (RHF) seeding technique. Resonance of the seed light is achieved by using a KD*P crystal to modify the phase of the light circulating within the slave oscillator cavity where the fast response of the crystal results in a seeding technique that is immune to noise throughout the acoustic regime.

A Dual Wavelength Ti:sapphire Laser Using A Ramp-Hold-Fire Seeding Technique for Resonance Ionization of Rb87

We present a novel dual wavelength ring laser for selective ionization of Rb87 atoms. The design incorporates a Ramp-Hold-Fire technique for generating 15ns Fourier transform limited pulses immune to noise within the acoustic range.

Hydraulic Modeling And Simulation Of Pumping Systems

Research Engineer at Southwest Research Institute, in San Antonio, Texas. His professional experiences include various experimental works, sales, technical support, drilling research assistant, and drilling laboratory teaching assistant. His Master’s thesis focused on cuttings transport velocity in horizontal and highly-inclined wells. In addition to his graduate work, he has been involved in research on double-piston pumps (experimental characterization and evaluation) and progressive cavity pumps (modeling development), as well as drilling fluids applications. Mr. Garcia has publications in areas such as cuttings transport in horizontal and deviated wells, gas and liquid pipeline transport, and centrifugal compressor surge analysis. Mr. Garcia-Hernandez holds a B.S. degree (Mechanical Engineering) from Central University of Venezuela and an M.S. degree (Petroleum Engineering) from the University of Tulsa.