Resident Research Associateships, Postdoctoral and Senior Research Awards Opportunities for Research (1986) / Chapter Skim
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Pages 47-57
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From page 47... ...
extension to other noble and refractory metal-silicide interfaces This research would pursue the UHV growth of thin silicides on (111)
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shear One application for such a modified fluid is m aircraft safety A jet fuel so modified would not form a mist in a crash, and hence the potential hazard from fire in a crash would be lessened The polymers are of a very high molecular weight and are used at concentrations of 0 1% to 0 5% The non-Newtonian behavior of such dilute polymer solutions is being investigated in order to ascertain the mechanism of the antimisting behavior Previous work has been concentrated on elongational flow using novel JPL-developed apparatus Future studies will extend these results and investigate more complex systems (e g, those which can be caused to gel by shear flow) , as well as amplify and modify current molecular and continuum mechanical theories of the flow of non-Newtonian fluids Pulse Radiolysis on Polymers in the Solid State A Gupta 44 40 04 03 Pulse radiolysis on liquids and solutions has been used to yield information on charge-recombination processes and reacuvity and decay modes of excited states and ion radicals Recent work on solid polymer films has demonstrated the existence of these processes in the solid state, which implies migration of charges and excitation energies along polymer chains Pulse radiolysis is also found to be an excellent tool for producing large populations of triplet excited states in these systems, which may then be monitored by time-resolved spectroscopy Physical and Chemical Aging of Polymers and Composites R Landel 44.40 04 04 Engineering properties (e.g , creep, suffness, durability)
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High-Temperature Desulfurization Sorbents M Flytzani-Stephanopoulos GE Voecks 44 40 04 05 Current research has identified certain types of sorbents with improved physicochemical characteristics for desulfurization of hot, coal-derived gas streams The principal characteristics of the sorbents under investigation are rapid kinetics of absorption and good regenerability One class of sorbents involves supported binary oxide mixtures (Zn-V-O, Cu-Mo-O, etc ) , which form a eutectic melt (below 700°C)
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include freeze drying of cells, purification of materials, experiments in quantum fluids, study of the liquid surface of reactive materials, m sttu characterization of spaceborne particulates, and study of reactions on dust grains. The aim of the research is to develop apparatus that will meet the requirements of the applicauons and to formulate interesting experiments that make use of the apparatus There are two research opportunities for the study of the electrohydrodynamics of free liquid drops One opportunity is for theoretical and computational study of the modes of electrically excited compound liquid drops The other is for experimental study uulizing neutral buoyant liquids in the laboratory and free drops in the microgravity afforded by aircraft flight along ballistic trajectory Medical Applications of Ultrasound J A Rooney 44 40 04 08 Ultrasonic imaging techniques and instrumentation have gained wide acceptance as safe, noninvasive diagnostic tools Further research is needed to increase the resolution of these systems, develop a capability to make reproducible serial measurements, improve image processing, and develop instrumentauon for new applications Current research projects include studies of the progression and regression of atherosclerosis, investigation of cardiovascular deconditioning in spaceflight, and left-ventricular image processing and monitoring the onset of decompression sickness The research is conducted with collaborators at the University of Southern California School of Medicine and the Johnson Space Center Opportuniues to be involved in these activiues exist for applicants with backgrounds in biophysics, ultrasound, biomedical engineering, physiology, and signal or image processing Reference J A Rooney et al, I E E E Trans Sonics Ultrason SU-28, 291 (1981)
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helium have been studied in zero-gravity rocket and aircraft flights and will be studied further, in conjunction with studies of capillary waves, in upcoming Shutde expenments. 'He IS to be studied theoreUcally and in the laboratory m order to determine the best way of utilizing it in space to attain temperatures near 0 3 K Development and Application of Far-Infrared Detectors and Ultrastable Frequency Standards V
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Propulsion for Sample-Return Missions W.L. Dowler 44.40.04.12 The return of samples from above, on, or below the surface is being rapidly recognized as a main objecuve of planetary exploration for the next several decades The amounts of energy required by this class of missions taxes severely both the capabibty of Earth launch vehicles -- necessitating in many cases multiple launches accompanied by orbital assembly -- as well as of planetary landing systems where enurely new braking devices have to be devised owing to the very large quantities of chemical propellants needed.
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in a bactenum for the generation of fusions between the gene for a metalloprotein acUve in electron transfer and the gene for an enzyme The general interest of this work is in the possibility of demonstrating allostenc effects between the substrate recogniuon site of the enzyme and the metal binding site of the metalloprotein that may form the basis for the development of speafic biochemical sensors Global Biology M N Dastoor 44.40 04 15 An understanding of the natural metabolism responsible for the maintenance of the steady-state composition of the atmosphere, oceans, and sediments on the surface of our planet is of significance not only to the science of comparative planetology but also to many applied problems concerning the persistence of the environment that supports human and other life Since such a metabolism is now and has for some time in the past been dynamic -- with physical, chemical, and biological processes inextricably linked -- quanuficauon of the biotic contribuuon is essential to a complete understanding of global processes. One way of determining this contribution is through modeling Even the most comprehensive models of exogenic cycles suffer from a dearth of valid global ground data It would be safe to contend that most, if not all, of the existing values for global-reservoir content and interreservoir fluxes are gross extrapolauons of very meager and somewhat outdated ground-based measurements In addition, owing to the relatively recent acceptance of the hypotheses of bioUc factors as potential homeostatic controls of some biogeochemical cycles, global data about the biota have traditionally lagged behind those relating to inorganic and nonbiological transformations The recogniuon of the biota in providing global homeostatic control factors can be attributed to biological reacuons that characteristically allow for extremely high chemical fluxes and quite often are masked by what appears to be a very modest net synthesis on a globale scale.
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planets requires larger, more spohisucated lander/sample return spacecraft. Advanced high thrust-to-weight rauo propulsion systems will be required to enable these missions Orbiter/probe missions to the outer planets require flight umes of 10-15 years with the most advanced chemical and nuclear electric-propulsion systems planned for development Significant advances in propulsion system performance, operauonal life, reliability, and autonomy will be required to enable these missions Further reductions in trip time for this mission or for more ambiuous missions will require the development of new propulsion concepts Ongoing work at JPL is directed toward the development and evaluauon of new advanced propulsion concepts Concepts are evaluated analyucally and experimentally when feasible.
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farming is the obvious method of choice for food regeneration, weight-volume constraints suggest alternative approaches. Photocatalysis and photoelectrocatalysis research is being earned out for the conversion of selected waste products to usable substrates for further biological conversion.
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Foam Material Studies W.M. Akutagawa T.G.
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rendering the pellet spherically symmetric, and to the technology of applying multilayer coatings to the exterior surface Opportunities exist for both experimental and theoretical studies Application of NMR to Material, Imaging, Metabolic, and Biochemical Studies SL Manatt DD EUeman 44 40 04 25 The great utility of nuclear magnetic resonance (NMR) stems from the variety of parameters that affect the spectra, and the fact that conditions can be chosen such that signal amplitude is directly proportional to the concentration of the nuclei being observed There has been work carried out in the field of NMR continuously at JPL since 1956 These is currently interest m applying our experience in this area along with JPL's extensive experience in cryogenic techniques and biochemical image processing to NMR imaging Also, research related to the apphcation of high-resolution NMR techniques to characterization of complex molecules and polymers is also possible JPL has access to the Caltech Southern California Regional HighField NMR Facihty (Bruker WM-500 Spectrometer)
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