Method and apparatus for contour mapping using synthetic aperture radar

By using two SAR antennas spaced a known distance, B, and oriented at substantially the same look angle to illuminate the same target area, pixel data from the two antennas may be compared in phase to determine a difference delta phi from which a slant angle theta is determined for each pixel point from an equation Delta phi = (2 pi B/lambda)sin(theta - alpha), where lambda is the radar wavelength and alpha is the roll angle of the aircraft. The height, h, of each pixel point from the aircraft is determined from the equation h = R cos theta, and from the known altitude, a, of the aircraft above sea level, the altitude (elevation), a', of each point is determined from the difference a - h. This elevation data may be displayed with the SAR image by, for example, quantizing the elevation at increments of 100 feet starting at sea level, and color coding pixels of the same quantized elevation. The distance, d, of each pixel from the ground track of the aircraft used for the display may be determined more accurately from the equation d = R sin theta

Vacuum ultraviolet photolysis of hydrogenated amorphous carbons. III. Diffusion of photo-produced H2 as a function of temperature

Hydrogenated amorphous carbon (a-C:H) has been proposed as one of the carbonaceous solids detected in the interstellar medium. Energetic processing of the a-C:H particles leads to the dissociation of the C-H bonds and the formation of hydrogen molecules and small hydrocarbons. Photo-produced H2 molecules in the bulk of the dust particles can diffuse out to the gas phase and contribute to the total H2 abundance. We have simulated this process in the laboratory with plasma-produced a-C:H and a-C:D analogs under astrophysically relevant conditions to investigate the dependence of the diffusion as a function of temperature. Plasma-produced a-C:H analogs were UV-irradiated using a microwave-discharged hydrogen flow lamp. Molecules diffusing to the gas-phase were detected by a quadrupole mass spectrometer, providing a measurement of the outgoing H2 or D2 flux. By comparing the experimental measurements with the expected flux from a one-dimensional diffusion model, a diffusion coefficient D could be derived for experiments carried out at different temperatures. Dependance on the diffusion coefficient D with the temperature followed an Arrhenius-type equation. The activation energy for the diffusion process was estimated (ED(H2)=1660+-110 K, ED(D2)=2090+-90 K), as well as the pre-exponential factor (D0(H2)=0.0007+0.0013-0.0004 cm2 s-1, D0(D2)=0.0045+0.005-0.0023 cm2 s-1) The strong decrease of the diffusion coefficient at low dust particle temperatures exponentially increases the diffusion times in astrophysical environments. Therefore, transient dust heating by cosmic rays needs to be invoked for the release of the photo- produced H2 molecules in cold PDR regions, where destruction of the aliphatic component in hydrogenated amorphous carbons most probably takes place

Thermal behavior of radiation damage cascades via the binary collision approximation: Comparison with molecular dynamics results

Based on the profile of the energy deposition obtained using the binary collision model, we follow the diffusion of energy by solving a simplified version of the heat equation. An estimation of the molten zone compares very well with the molecular dynamics prediction for the same event. We discuss the reasons for this agreement and the relevance of such simplified procedure in terms of present-day computer limitations to simulate high energy cascades using molecular dynamic

'Getting out of the closet': Scientific authorship of literary fiction and knowledge transfer

Some scientists write literary fiction books in their spare time. If these books contain scientific knowledge, literary fiction becomes a mechanism of knowledge transfer. In this case, we could conceptualize literary fiction as non-formal knowledge transfer. We model knowledge transfer via literary fiction as a function of the type of scientist (academic or non-academic) and his/her scientific field. Academic scientists are those employed in academia and public research organizations whereas non-academic scientists are those with a scientific background employed in other sectors. We also distinguish between direct knowledge transfer (the book includes the scientist's research topics), indirect knowledge transfer (scientific authors talk about their research with cultural agents) and reverse knowledge transfer (cultural agents give scientists ideas for future research). Through mixed-methods research and a sample from Spain, we find that scientific authorship accounts for a considerable percentage of all literary fiction authorship. Academic scientists do not transfer knowledge directly so often as non-academic scientists, but the former engage into indirect and reverse transfer knowledge more often than the latter. Scientists from History stand out in direct knowledge transfer. We draw propositions about the role of the academic logic and scientific field on knowledge transfer via literary fiction. We advance some tentative conclusions regarding the consideration of scientific authorship of literary fiction as a valuable knowledge transfer mechanism.Comment: Paper published in Journal of Technology Transfe