Engineering topics
Publications and source records attributed to Smith, Greg.
The primary deliverable for this project will be to construct a power electronics package utilizing an organic, electrically insulating substrate material and demonstrate superior thermal performance and greater reliability under thermal cycling, thermal aging, vibration, power cycling, and electrical high-potential evaluation over traditional packages.
The development of mid-infrared, high-energy pulses of extremely short pulse duration is of great importance to the strong-field physics community, as it enables extension of the high-harmonic cutoff towards the keV range of photon energies. Here we demonstrate a C r 2 + : Z n S e laser amplifier delivering 7 mJ, 100 fs pulses at 1 kHz repetition rate and 2.4 µm central wavelength with excellent energy stability and beam quality. These pulses are post-compressed to 39 fs, 6.2 mJ, and 115 GW peak power in a novel nonlinear compression scheme. The laser system was used to generate coherent soft x-ray radiation up to 0.6 keV covering the entire water window, which is of high importance for bio-relevant applications. The obtained results open a wide range of applications in nonlinear optics, attosecond and strong-field physics, and remote sensing.
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The Qweak ep elastic scattering experiment used to extract an asymmetry at Q 2 = 0.0248 GeV 2 will be described. The final result was -226.5 ± 9.3 ppb- the most precise ep asymmetry ever measured. Some of the backgrounds and corrections applied in the experiment will be explained and quantified, and some of the experimental challenges will be described. Several methods used to extract consistent values of the proton’s weak charge Q w(p) from our asymmetry measurement will be outlined. We also show the multi-TeV mass reach for beyond-the-Standard-Model physics obtained from our determination of the proton’s weak charge, and discuss our sensitivity to specific examples of new physics like compositeness. From the proton’s weak charge, a result for the fundamental standard model parameter sin 2 θ W is obtained at the energy scale of our experiment. We compare that to the few other determinations of sin 2 θ W available in the literature, as well as the predicted behaviour based on SM input.
The Forward-Looking Interferometer (FLI) is a new instrument concept for obtaining the measurements required to alert flight crews to potential weather hazards to safe flight. To meet the needs of the commercial fleet, such a sensor should address multiple hazards to warrant the costs of development, certification, installation, training, and maintenance. The FLI concept is based on high-resolution Infrared Fourier Transform Spectrometry (FTS) technologies that have been developed for satellite remote sensing. These technologies have also been applied to the detection of aerosols and gases for other purposes. The FLI concept is being evaluated for its potential to address multiple hazards including clear air turbulence (CAT), volcanic ash, wake vortices, low slant range visibility, dry wind shear, and icing during all phases of flight (takeoff, cruise, and landing). The research accomplished in this second phase of the FLI project was in three major areas: further sensitivity studies to better understand the potential capabilities and requirements for an airborne FLI instrument, field measurements that were conducted in an effort to provide empirical demonstrations of radiometric hazard detection, and theoretical work to support the development of algorithms to determine the severity of detected hazards
This viewgraph presentation describes a case study as a model for integrated project management. The ISS Program Office (ISSPO) developed replacement fluid filtration cartridges in house for the International Space Station (ISS). The presentation includes a step-by-step procedure and organizational charts for how the fluid filtration problem was approached.
Schedule Risk Assessment needs to determine the probability of finishing on or before a given point in time. Task in a schedule should reflect the "most likely" duration for each task. IN reality, each task is different and has a varying degree of probability of finishing within or after the duration specified. Schedule risk assessment attempt to quantify these probabilities by assigning values to each task. Bridges the gap between CPM scheduling and the project's need to know the likelihood of "when".
Schedule risk assessments determine the likelihood of finishing on time. Each task in a schedule has a varying degree of probability of being finished on time. A schedule risk assessment quantifies these probabilities by assigning values to each task. This viewgraph presentation contains a flow chart for conducting a schedule risk assessment, and profiles applicable several methods of data analysis.
Several new K type asteroids were identified during near infrared spectral observations on July 30, 1992 at NASA's infrared telescope facility (IRTF) at Mauna Kea, Hawaii. These K asteroids are 513 Centesima, 633 Zelima, 1129 Neujmina, 1416 Renauxa, 1799 Koussevitzky, and 1883 Rauma. A K asteroid is an asteroid which possesses a S type spectra in visible wavelengths and a C type spectra visible in near-infrared wavelengths. These objects are usually misclassified as S asteroids on the basis of visible spectra alone. This type was first detected by the 52 infrared color asteroid survey also conducted at the IRTF. Our observations utilized a new seven color infrared asteroid filter system which allows near-infrared data to be collected from asteroids as faint as 16th 5 magnitude.
This is the Software Concept Document for the Man-machine Integration Design and Analysis System (MIDAS) being developed as part of Phase V of the Army-NASA Aircrew/Aircraft Integration (A3I) Progam. The approach taken in this program since its inception in 1984 is that of incremental development with clearly defined phases. Phase 1 began in 1984 and subsequent phases have progressed at approximately 10-16 month intervals. Each phase of development consists of planning, setting requirements, preliminary design, detailed design, implementation, testing, demonstration and documentation. Phase 5 began with an off-site planning meeting in November, 1990. It is expected that Phase 5 development will be complete and ready for demonstration to invited visitors from industry, government and academia in May, 1992. This document, produced during the preliminary design period of Phase 5, is intended to record the top level design concept for MIDAS as it is currently conceived. This document has two main objectives: (1) to inform interested readers of the goals of the MIDAS Phase 5 development period, and (2) to serve as the initial version of the MIDAS design document which will be continuously updated as the design evolves. Since this document is written fairly early in the design period, many design issues still remain unresolved. Some of the unresolved issues are mentioned later in this document in the sections on specific components. Readers are cautioned that this is not a final design document and that, as the design of MIDAS matures, some of the design ideas recorded in this document will change. The final design will be documented in a detailed design document published after the demonstrations.
A catalog of fasteners is presented for a variety of applications to be used in a lunar environment. The fastening applications targeted include: covers, panels, hatches, bearings, wheels, gears, pulleys, anchors for the lunar surface and structural fasteners (general duty preloadable). The robotic installation and removal of each fastener is presented along with a discussion of failure modes. Structural performance data is tabulated for various configurations. Potential materials for the space environment are presented along with recommendations of appropriate solid film lubricants. Three original fastener designs were found suitable for the lunar environment. A structural analysis is presented for each original design.