Growth of yeasts on synthetic carbohydrates
Yeasts growth on synthetic carbohydrates with crude formose sugars, discussing application as regenerating food in long term closed life support system
Chermside, H. B.↗
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Formation of spectral lines in planetary atmospheres. III - The use of analytic scattering diagrams in computations of synthetic spectra for cloudy atmospheres.
Results of some comparisons that have been made of line profiles and equivalent widths computed from atmospheric models where the scattering has been represented by the Mie theory and a simple analytic expression, the Heyney-Greenstein function. These results show that the spectroscopic features for these models are indistinguishable and demonstrate the value of using this simple analytic function in terms of the great saving in computer time when computing synthetic spectra for any cloudy planetary atmosphere.
Hunt, G. E.↗
Antenna dimensions of synthetic aperture radar systems on satellites
Design of a synthetic aperture radar (SAR) for a satellite must take into account the limitation in weight and dimensions of the antenna. The lower limits of the antenna area are derived from the conditions of unambiguity of the SAR system. This result is applied to estimate the antenna requirements for SARs on satellites in circular orbits of various altitudes around Earth and Venus.
Richter, K. R.↗
Processing for spaceborne synthetic aperture radar imagery
The data handling and processing in using synthetic aperture radar as a satellite-borne earth resources remote sensor is considered. The discussion covers the nature of the problem, the theory, both conventional and potential advanced processing techniques, and a complete computer simulation. It is shown that digital processing is a real possibility and suggests some future directions for research.
Lybanon, M.↗
The use of a simulator in a synthetic aperture radar data processing tradeoff study.
A computer simulation of a synthetic aperture radar system is described. The objective in developing the simulator was to make it possible to assess the imaging performance of various configurations against a variety of target types. The simulation involves targets, the radar system itself, and the processor; several analysis and output options are provided. Targets may be internally generated or come from external sources, or externally produced (e.g., real) radar signals can be used. A number of parameters of the radar system can be varied. The characteristics of the processor can be adjusted to a considerable extent. Statistical analyses may be performed. Several output options are available, including imagery.
Lybanon, M.↗
Synthetic carbohydrate: An aid to nutrition in the future
The synthetic production of carbohydrate on a large scale is discussed. Three possible nonagricultural methods of making starch are presented in detail and discussed. The simplest of these, the hydrolysis of cellulose wastes to glucose followed by polymerization to starch, appears a reasonable and economic supplement to agriculture at the present time. The conversion of fossil fuels to starch was found to be not competitive with agriculture at the present time, but tractable enough to allow a reasonable plant design to be made. A reconstruction of the photosynthetic process using isolated enzyme systems proved technically much more difficult than either of the other two processes. Particular difficulties relate to the replacement of expensive energy carrying compounds, separation of similar materials, and processing of large reactant volumes. Problem areas were pinpointed, and technological progress necessary to permit such a system to become practical is described.
Berman, G. A.↗
Elastohydrodynamic film thickness formula based on X-ray measurements with a synthetic paraffinic oil
An empirical elastohydrodynamic film thickness formula for heavily loaded contacts based upon X-ray film thickness measurements made with a synthetic paraffinic oil is presented. The deduced relation was found to adequately reflect the high load dependence exhibited by the measured minimum film thickness data at high Hertizian contact stresses, that is, above 1.04 x 10 to the ninth N/sq m (150,000 psi). Comparisons were made with the numerical results from a theoretical isothermal film thickness formula. The effects of changes in contact geometry, material, and lubricant properties on the form of the empirical model are also discussed.
Loewenthal, S. H.↗
The effect of synthetic homopolymer poly I:C on the synthesis of nucleic acids, protein and interferon in spleen cells normally and with radiation
A comparative study is reported of the effect of the synthetic homopolymer poly I:C and Newcastle Disease virus on the synthesis of RNA, DNA, total protein and interferon in the spleen of nonradiated and radiated mice. In radiated animals, poly I:C and NDV had no stimulating effect on the synthesis of RNA; administration of both inducers to radiated mice did not significantly affect the content of lymphoid cellular elements in the spleen. However, while reduction of RNA synthesis, caused by radiation, also increases slightly under the effect of poly I:C and the virus, the synthesis of interferon in spleen cells and in the entire body is activated.
Antropova, Y. N.↗
Space shuttle synthetic aperture radar
Results of a feasibility study to investigate a digital signal processor for real-time operation with a synthetic aperture radar system aboard the space shuttle are presented. Pertinent digital processing theory, a description of the proposed system, and size, weight, power, scheduling, and development estimates are included.
Source record↗
Rolling-element fatigue life with two synthetic cycloaliphatic traction fluids
The life potential of two synthetic cycloaliphatic hydrocarbon traction fluids in rolling element fatigue was evaluated in a five ball fatigue tester. Life comparisons with a MIL-L-23699 qualified tetraester oil showed that the traction test oils had good fatigue life performance, comparable to that of the tetraester oil. No statistically significant life differences between the traction fluids and the tetraester oil were exhibited under the accelerated fatigue test conditions. Erratic operating behavior was occasionally encountered during tests with the antiwear additive containing traction fluid for reasons thought to be related to excessive chemical activity under high contact pressure. This behavior occasionally resulted in premature test termination due to excessive surface distress and overheating.
Loewenthal, S. H.↗
A global search and rescue concept using synthetic aperture radar and passive user targets
A terrestrial search and rescue concept is defined embodying the use of passive radio-frequency reflectors in conjunction with an orbiting synthetic aperture radar to detect, identify, and locate users. An airborne radar test was conducted to evaluate the basic concept. In this test simple corner-reflector targets were successfully imaged. Results from this investigation were positive and indicate that the concept can be used to investigate new approaches focused on the development of a global search and rescue system.
Sivertson, W. E., Jr.↗
Shuttle synthetic aperture radar implementation study, volume 1
Results of an implementation study for a synthetic aperture radar for the space shuttle orbiter are described. The overall effort was directed toward the determination of the feasibility and usefulness of a multifrequency, multipolarization imaging radar for the shuttle orbiter. The radar is intended for earth resource monitoring as well as oceanographic and marine studies.
Mehlis, J. G.↗
The use of a very high temperature nuclear reactor in the manufacture of synthetic fuels
The three parts of a program directed toward creating a cost-effective nuclear hydrogen production system are described. The discussion covers the development of a very high temperature nuclear reactor (VHTR) as a nuclear heat and power source capable of producing the high temperature needed for hydrogen production and other processes; the development of a hydrogen generation process based on water decomposition, which can utilize the outputs of the VHTR and be integrated with many different ultimate hydrogen consuming processes; and the evaluation of the process applications of the nuclear hydrogen systems to assess the merits and potential payoffs. It is shown that the use of VHTR for the manufacture of synthetic fuels appears to have a very high probability of making a positive contribution to meeting the nation's energy needs in the future.
Farbman, G. H.↗
A study of the toxicology of pyrolysis gases from synthetic polymers
An apparatus and procedure for evaluating the toxicity of pyrolysis gases from synthetic polymers are described. In each test, four Swiss albino mice are exposed in a 5-liter chamber to the gases from materials pyrolyzed at 700 C. The apparatus is simple in design, easy to clean, inexpensive and gives reproducible results. Data on several fluorine-containing and polyamide polymers are presented.
Young, W.↗
A synthetic aperture processor using CCD signal processing techniques
Synthetic aperture radar (SAR) imaging was the most suitable technique for achieving high resolution imagery through atmospheric cloud cover. This feature was important for planetary as well as earth orbiting satellite systems, and for military aircraft applications. Such applications require onboard data processing or wide-band data transmission systems in order to handle the large amounts of raw data produced by such systems. A number of techniques were utilized in implementing SAR processors. Frequency filtering and Fourier transform operations using both optical and digital techniques were utilized in SAR processing.
Bailey, W. H.↗
Internal wave observations made with an airborne synthetic aperture imaging radar
Synthetic aperture L-band radar flown aboard the NASA CV-990 has observed periodic striations on the ocean surface off the coast of Alaska which have been interpreted as tidally excited oceanic internal waves of less than 500 m length. These radar images are compared to photographic imagery of similar waves taken from Landsat 1. Both the radar and Landsat images reveal variations in reflectivity across each wave in a packet that range from low to high to normal. The variations point to the simultaneous existence of two mechanisms for the surface signatures of internal waves: roughening due to wave-current interactions, and smoothing due to slick formation.
Elachi, C.↗
Study of Arctic sea ice drift from L-band synthetic aperture radar
As part of the Arctic Ice Dynamics Joint Experiment (AIDJEX) several repetitive coverages of L-band (25 cm wavelength) side-looking airborne radar images have been flown over coastal areas of Alaska and a test area in the Arctic. These images allow the analysis of sea ice and its drift. Radar is particularly suited for the mapping and interpretation of Arctic sea ice due to independence from sunlight and the capability to penetrate clouds. Ice floes and leads can be readily identified on the radar images. Measurement of ice floe drift is based on the transformation of radar image coordinates into a geocentric coordinate system using inertial guidance data from the survey aircraft. The paper will demonstrate an example of Arctic ice drift measurements from L-band synthetic aperture radar imagery with an absolute accuracy of about 5%. The conclusions are of particular value in view of planned spaceborne side-looking radar missions in polar orbits.
Leberl, F.↗
Effects of random phase changes on the formation of synthetic aperture radar imagery
The effects of Gaussian random fluctuation and linear change of the echo phase on the response of the azimuth matched processor of a synthetic aperture radar (airborne or spaceborne for ocean-surface sensing) is analyzed numerically. It is found that the random fluctuation would not alter appreciably the processor response if its standard deviation is less than pi, while its normalized correlation time is larger than 1. If these two bounding conditions are not satisfied, then the sidelobe level becomes relatively large and overshadows the central peak. In the case of linear displacement it is found that the main effect is the spatial displacement of the point scatterer in the image plane.
Elachi, C.↗