analytical and numerical work. The success of DLCQ in 1 + 1 dimensions provides the hope of solving theories in three space and one time dimensions. The application to higher dimensions is much more involved than in 1 + 1 dimensions due to the need to introduce ultraviolet and infrared regulators, and invoke a renormalization scheme consistent with gauge invariance and Lorentz invariance. This is in addition to the extra work involved implementing two extra dimensions with their added degrees of freedom. The application is presented of DLCQ to 3 + 1 dimensional Quantum Electrodynamics. N91-10791# IIT Research Inst., Bartlesville, OK. DETERMINATION OF IDEAL-GAS ENTHALPIES OF FORMATION FOR KEY COMPOUNDS: THE 1988 PROJECT RESULTS DOE W. V. Steele, R. D. Chirico, A. Nguyen, I. A. Hossenlopp, and N. K. Smith Jul. 1990 46 p (Contract DE-FC22-83FE-60149) (DE90-000247; NIPER-422) Avail: NTIS HC/MF A04 The results of a study aimed at improvement of group contribution methodology for estimation of thermodynamic properties of organic substances are reported. Specific weakness where particular group-contribution terms were unknown, or estimated because of lack of experimental data, are addressed by experimental studies of enthalpies of combustion in the condensed phase and vapor pressure measurements. Ideal-gas enthalpies of formation are reported for 3-methylbuta 1,2-diene; 2,5-dimethylhexa 2,4-diene; acetaldoxime; N,N-diethyl hydroxylamine; 1-methylpyrrolidin-2-one; and phenanthrene. Solid and liquid phase enthalpies of formation at 298.15 K are determined for benzamide. Ring corrections, group terms, and next-nearestneighbor interaction terms useful in the application of group contribution correlations are derived. DOE A prototype project management system was developed for the Level III Project Office for the Space Station Freedom. The main goal was to establish a framework for the Space Station Project Office whereby Project and Office Managers can jointly establish and review scheduled milestones and activities. The objective was to assist office managers in communicating their objectives, milestones, schedules, and other project information more effectively and efficiently. Consideration of sophisticated project management systems was included, but each of the systems had limitations in meeting the stated objectives. Author N91-10794*# Houston Univ., Clear Lake, TX. Research Inst. for Computing and Information Systems. APPLIED TECHNOLOGY CENTER BUSINESS PLAN AND Robert F. Hodgin and Roberto Marchesini [1990] 68 p (NASA-CR-187259; NAS 1.26:187259) Avail: NTIS HC/MF A04 CSCL 05B Business plan and market survey for the Applied Technology Center (ATC), computer technology transfer and development non-profit corporation, is presented. The mission of the ATC is to stimulate innovation in state-of-the-art and leading edge computer based technology. The ATC encourages the practical utilization of late-breaking computer technologies by firms of all variety. Author N91-10795*# Houston Univ., Clear Lake, TX. Research Inst. Robert F. Hodgin and Roberto Marchesini Mar. 1987 39 p (NASA-CR-187252; NAS 1.26:187252) Avail: NTIS HC/MF A03 CSCL 05A The goal of the Space Market Model (SMM) is to develop an information resource for the space industry. The SMM is intended to contain information appropriate for decision making in the space industry. The objectives of the SMM are to: (1) assemble information related to the development of the space business; (2) construct an adequate description of the emerging space market; (3) disseminate the information on the space market to forecasts and planners in government agencies and private corporations; and (4) provide timely analyses and forecasts of critical elements of the space market. An Input-Output model of market activity is proposed which are capable of transforming raw data into useful information for decision makers and policy makers dealing with the space sector. Author (PB90-171737; GP-3.34:85-86) Avail: NTIS HC/MF A99 The catalog is a finding aid for the reports and documents of GRA N91-10798*# National Aeronautics and Space Administration. BIBLIOGRAPHY OF LEWIS RESEARCH CENTER TECHNICAL May 1990 399 p (NASA-TM-102542; E-5352; NAS 1.15:102542) Avail: NTIS This compilation of abstracts describes and indexes the N91-10799# National Oceanic and Atmospheric Administration, Office. EARTH SYSTEM MONITOR, VOLUME 1, NUMBER 1, JUNE A. H. Horvitz Jun. 1990 8 p (PB90-215146) Avail: NTIS HC/MF A02 CSCL 05B The Earth Systems Monitor, issued 2 to 3 times a year as N91-10800# National Inst. of Standards and Technology, NIST RESEARCH REPORTS, MAY 1990 (PB90-244435; NIST/SP-783) Avail: NTIS HC/MF A03; also A collection of research reports and updates from the National Railroad Train. A few topics covered are the use of pulsed lasers M.G. N91-10801# China Nuclear Information Centre, Beijing. (DE90-627893; CNIC-00257; BUGRI-0005) Avail: NTIS (US By using the computer integration technique, the multiple N91-10802# Lawrence Livermore National Lab., CA. (Contract W-7405-eng-48) (DE90-014797; UCRL-ID-103495-89) Avail: NTIS HC/MF A04 N91-10803# Los Alamos National Lab., NM. AN INTERPERSONAL MULTIMEDIA VISUALIZATION SYSTEM Media View is a computer program that provides a generic NASA THESAURUS SUPPLEMENT: A FOUR PART CUMULATIVE SUPPLEMENT TO THE 1988 EDITION OF THE NASA THESAURUS (SUPPLEMENT 4) Semiannual Report Sep. 1990 26 p (NASA-SP-7064-Suppl-4; NAS 1.21:7064-Suppl-4) Avail: NTIS HC/MF A03 CSCL 05B The four-part cumulative supplement to the 1988 edition of the NASA Thesaurus includes the Hierarchical Listing (Part 1), Access Vocabulary (Part 2), Definitions (Part 3), and Changes (Part 4). The semiannual supplement gives complete hierarchies and accepted upper/lowercase forms for new terms. Author 83 ECONOMICS AND COST ANALYSIS Includes cost effectiveness studies. No abstracts in this category. 84 LAW, POLITICAL SCIENCE AND SPACE POLICY Includes NASA appropriation hearings; aviation law; space law and policy; international law; international cooperation; and patent policy. No abstracts in this category. 85 URBAN TECHNOLOGY AND TRANSPORTATION Includes applications of space technology to urban problems; technology transfer; technology assessment; and surface and mass transportation. For related information see also 03 Air Transportation and Safety, 16 Space Transportation, and 44 Energy Production and Conversion. N91-10805# Federal Lab. Consortium, Washington, DC. (PB90-215187) Avail: NTIS HC/MF A05 CSCL 05A The report was compiled and produced by the Federal Laboratory Consortium, which works to improve and promote technology transfer by assisting businesses and others to identify the 'right' federal laboratory contacts in their fields of infrastructure for cooperation. The document is also a collection of examples from 14 laboratories representing 6 government agencies. A similar document was issued in 1988 and is available through the National Technical Information Service. Both sets of examples are indicative of the full potential for industry-laboratory cooperation to contribute to the nation's economic strength. GRA 88 SPACE SCIENCES (GENERAL) No abstracts in this category. 89 ASTRONOMY Includes radio, gamma-ray, and infrared astronomy, and astrometry. N91-10806 Arizona Univ., Tucson. ESTIMATION OF ASTRONOMICAL IMAGES FROM THE Jonathan Dennis Freeman 1989 164 p The uses of the bispectrum for recovering the images of one-dimensional infrared astronomical speckle data are examined. An analytic model for the bispectral transfer function, the variance, and the covariance of the bispectrum are developed. The models are evaluated by Monte Carlo integration and the results are compared to sample estimates of the same quantities obtained from simulated data. For comparison, the same sample quantities are computed from observed data. The bispectrum is shown to be useful for determining estimates of the object phase. A recursive method which is used to obtain the object phase estimates is introduced. Since the bispectrum provides multiple estimates of each object phase, a number of methods for combining the multiple estimates are developed and compared. Many techniques were proposed to determine the phase of images which were atmospherically distorted. Among these techniques are the Knox-Thompson, and the Simple Shift-and-Add algorithms. These methods are compared to the bispectrum via an objective measure which is developed. Optimization techniques are used to great success. A model for the bispectrum of a binary star is developed and fit to the image bispectrum by the Levenberg-Marquardt algorithm for non-linear least squares. The ability of the algorithm to determine binary star parameters from the bispectrum is tested with both simulated and observed data. Since the bispectrum may not always be available, a method is developed which determines binary star parameters from the image Fourier transform. The full set of object phases and moduli are determined by use of the conjugate gradient and conjugate direction algorithms. Two starting points for each algorithm are employed. The first starting point uses the estimates of the object phases obtained from the recursive bispectrum technique. The second assumes no information is known about the object. The speed of convergence of each algorithm is analyzed and recommendations are made for future Dissert. Abstr. use. The use of Cherenkov imaging for background reduction in TeV Astronomy is described. The technique of measuring the angular distribution of Cherenkov light from air showers as a means of identifying the primary particle type has been predicted to lead to a significant increase in the sensitivity for ground-based gamma ray telescopes. The hardware test of imaging successfully finds the Cherenkov light patterns from local cosmic ray particles using the Whipple Observatory collaboration's air Cherenkov telescope. This shows that a Whipple type imaging detector is sensitive to subtle images and therefore suitable for such a technique. A Monte Carlo simulation test confirms the current knowledge of the angular distribution of Cherenkov light expected from gamma ray induced air showers. The search for TeV photons from two massive x-ray binaries, 4U0115+63 and VO332+53, using both uncut and image selected data sets shows little evidence for emission from either source. N91-10808 Dissert. Abstr. Max-Planck-Inst. fuer Physik und Astrophysik, Garching (Germany, F.R.). Inst. fuer Extraterrestrische Physik. BICOLORED PHOTOMETRY AND SPECTRAL ACCOMMODATION IN X-RAY REGION OF MASS IMPREGNATED STELLAR X-RAY BINARIES Thesis Ludwig-Maximilians-Univ. [ZWEIFARBENPHOTOMETRIE UND SPEKTRALE ANPASSUNG IM ROENTGENBEREICH AN MASSEARMEN ROENTGENDOPPELSTERNEN] Norbert S. Schulz Mar. 1990 166 p In GERMAN (MPE-219; ISSN-0178-0719; ETN-90-97872) Copyright Avail: Fachinformationszentrum Karlsruhe, 7514 Eggenstein-Leopoldshafen 2, Fed. Republic of Germany From June 1983 to April 1986 onwards, a great number of light galactic X-ray sources were observed several times at long intervals at the EXOSAT European X-ray Observatory. Among the lightest of these sources, the so called mass-impregnated X-ray binaries (LMXBs) are found. LMXBs are semi-separated contact systems composed of a neutron star and of a mass-impregnated satellite star. The neutron star receives substance from its satellite star, thus developing an accretion disk. The liberated gravitational energy is observed at collision on the neutron star surface under the form of X-ray radiation. Among the most well known subjects of this system are Sco X-1, Cyg X-2 and the light sources of the galactic bulge. They are the lightest extrasolar X-ray sources. A model of energy spectrum is used for the examination of a number of LMXB, with these radiation characteristics. Their most important physical properties are considered. The EXOSAT X-ray satellite and the MEAR-experiments are described. The methods of data reduction and the observation catalog are presented. ESA [ACTIVITIES REPORT OF THE EUROPEAN SOUTHERN 1990 128 p In ENGLISH, FRENCH, and GERMAN The work carried out by the several divisions, the observations performed, the staff international cooperation activities and conferences of the European Southern Observatory (ESO) are reported. The ESO's actions and achievements involving La Silla Observatory and efforts to finish the New Technology Telescope are underlined. The SN1987A observations are summarized. The activities of the European Coordination Facility for the Space Telescope are included. Researches on image processing and sky surveys are described. ESA N91-10424# Cologne Univ. (Germany, F.R.). Inst. fuer Geophysik und Meteorologie. CLUSTER AS A WAVE TELESCOPE F. M. Neubauer, K.-H. Glassmeier, R. Walter, and M. W. Dunlop (Imperial Coll. of Science and Technology, London, England) In ESA, Space Plasma Physics Investigation by Cluster and Regatta May 1990 p 51-55 Sponsored by BMFT and United Kingdom Science and Engineering Research Council (For primary document see N91-10417 01-46) Copyright Avail: NTIS HC/MF A08; EPD, ESTEC, Noordwijk, Netherlands HC 40 Dutch guilders 90 ASTROPHYSICS Includes cosmology; celestial mechanics; space plasmas; and interstellar and interplanetary gases and dust. For related information see also 75 Plasma Physics. N91-10810*# Maryland Univ., College Park. Dept. of Physics and Astronomy. THE JOINT NASA/GODDARD-UNIVERSITY OF MARYLAND (NASA-CR-180335; NAS 1.26:180335) Avail: NTIS HC/MF A03 CSCL 03B The Univ. of Maryland portion investigated the following areas. The Space Physics Group performed studies of data from the AMPTE/CCE spacecraft CHEM experiment and found that the ratio of solar wind to photospheric abundances decreased rather smoothly with the first ionization potential (FIP) of the ion with the low FIP ion being about a factor of two overabundant. Carbon and hydrogen fit this trend particularly well. Several occurrences were analyzed of field aligned beams observed when CCE was upstream of the Earth's bow shock. Also using CHEM data, ring current intensity and composition changes during the main and recovery phases of the great geomagnetic storm that occurred in February 1986 was examined in detail. Still using CHEM data, ring current characteristics were examined in a survey of 20 magnetic storms ranging in size from -50 nT to -312 nT. A study was done of energetic ion anisotropy characteristics in the Earth's magnetosheath region using data from the UMD/MPE experiment on ISEE-1. The properties were analyzed of approx. 30 to 130 keV/e protons and alpha particles upstream of six quasi-parallel interplanetary shocks that passed by the ISEE-3 spacecraft during 1978 to 1979. Work from NASA-Goddard include studies from the High Energy Cosmic Ray Group, Low Energy Cosmic Ray Group, Low Energy Gamma Ray Group, High Energy Astrophysics Theory Group, and the X ray Astronomy Group. E.R. N91-10811 Yale Univ., New Haven, CT. COSMOLOGICAL SINGULARITIES IN ELECTROVACUUM Philip Andrew Mansfield 1989 128 p The big bang singularities occurring in an infinite-dimensional class of solutions to the source-free Einstein-Maxwell equations are presented. These solutions are essentially Gowdy three-torus universes (not necessarily polarized) with electromagnetic radiation added. The problem is reformulated in terms of complex potentials analogous to those used by Ernst in the study of stationary axisymmetric metrics. It is shown that in these new variables the problem admits a harmonic map formulation. Its general solution is written as a perturbation series, where the background solutions being perturbed are a special class of real analytic functions obtained by evolving analytic data specified right at the singularity. The perturbation problem is solved to all orders, and terms which dominate as the singularity is approached are identified at each order. It is possible to sum the dominant terms, and thereby obtain explicit expressions representing the asymptotic structure of the singularities. This representation of asymptotic structure is developed into a simple geometric model. Specializing to the case of no electromagnetic fields, the model is then used to determine asymptotic metric and curvature properties in Gowdy spacetimes. The Gowdy metrics are Kasner-like near their singularity, which is generically a curvature singularity. Curvature-nonsingular solutions can be constructed, and extended into the past beyond a Cauchy horizon. However, such solutions are unstable, a fact which is consistent with Strong Cosmic Censorship. Dissert. Abstr. N91-10812 Cornell Univ., Ithaca, NY. LARGE SCALE STRUCTURES IN NONZERO LAMBDA FRIEDMANN UNIVERSES Ph.D. Thesis Avail: Univ. Microfilms Order No. DA9018044 Several theoretical and observational arguments suggest the existence of a nonzero cosmological constant Lambda. Since the presence of such constant would affect the growth of gravitational instabilities leading to the formation of large scale structures, detailed observations of these structures, combined with theoretical models, might help to determine, or rule out, the existence of the cosmological constant. The results of a detailed study of the formation and evolution of large scale structures in Friedmann models composed of non-relativistic, pressureless matter and a nonzero cosmological constant are presented. The main objective was to determine how large scale structures are affected by the presence of the cosmological constant, and whether introducing a nonzero Lambda in the model improves the fit to the observations. The results can help to decide which observational tests are most likely to yield a determination the value of Lambda. The main approach consists of deriving relations among various quantities characterizing the large scale structures and the Friedmann background, and to study the dependence of these relations upon the value of the cosmological constant. Analytical approximations are described. Linear perturbation theory for Lambda models is rederived, and a simple relation between the peculiar velocity field, the density parameter, and the cosmological constant is obtained. The properties of spherically symmetric systems in nonzero Lambda models are described. Analytical expressions for the density enhancement inside halos for zero and nonzero Lambdas are derived. Numerical simulations of cosmic voids are presented. The relation between density contrast, peculiar velocity field, initial perturbation, and the cosmological parameters is discussed in great detail. N body simulations of galaxy clustering in nonzero Lambda models are presented. The dependence of the two-point correlation function upon the cosmological constant is discussed. All results lead to the conclusion that studying the large scale structures is unlikely to provide definitive information on the value of the cosmological constant. Dissert. Abstr. Avail: Univ. Microfilms Order No. DA9013968 Optical CCD images, long-slit spectroscopic data, coadded IRAS fluxes, and global H I line profiles are analyzed for a sample of 125 Markarian galaxies reported earlier to possess multiple optical nuclei or extreme morphological peculiarities. Twenty-six objects are isolated which display the strongest evidence for ongoing mergers between disk galaxies; the remainder consist of separated interacting systems, single late-type galaxies with multiple giant H II regions, plus a few ambiguous objects. The merger candidates are involved in low velocity encounters. H alpha and far-infrared luminosities indicate star formation rates that are an average of 3 to 10 times higher than in isolated disk galaxies. The presence of 8 Seyfert nuclei and 5 LINERs among 52 merger nuclei indicates a higher incidence of AGNS compared to isolated spirals at a significance level of 99.9 percent, and there is a higher fraction of AGN pairs than would be expected if the merger process did not induce Seyfert-like activity. Evidence for coupling between the ionization levels of the paired nuclei suggests either mixing by gas transfer between the components, or a selection bias towards pairs of galaxies with similar mass and metal abundances. Correlations between nuclear emission-line properties and global FIR properties indicate that the nuclei and giant H II regions are responsible for the bulk of the FIR luminosity. Radio continuum maps and optical images of Markarian 266 reveal the presence of a strong synchrotron source located between the active nuclei. This is interpreted as shock-induced acceleration of cosmic rays during the ongoing merger of two disk galaxies. Large scale shocking of the interstellar medium may also trigger star formation and destroy large dust grains, resulting in warm far-infrared emission which characterizes colliding disk galaxies. Dissert. Abstr. N91-10814 Edinburgh Univ. (Scotland). VIGOROUS STAR FORMATION IN GALACTIC NUCLEI Ph.D. Thesis Philip John Puxley 1988 232 p Avail: Univ. Microfilms Order No. BRD-88486 Vigorous star formation in the nuclei of nearby galaxies is studied. A variety of techniques were employed to investigate several aspects of this phenomenon. Analysis of mid- and far-infrared data, taken by the Infrared Astronomical Satellite, suggests that among nearby spiral galaxies the presence of a stellar bar is a necessary condition for the existence of vigorous star-formation activity. Such regions contribute, on average, one third of the luminosity of the host galaxy. Medium-resolution radio continuum observations show that active star formation occurs in the central regions of galaxies, supporting the hypothesis that it is caused by a bar-driven inflow of disk material. Near-infrared spectrophotometry was used to study several of these highly dust-obscured regions in greater detail. Detection of the hydrogen recombination line Br gamma, which arises in photoionized gas, is further evidence for the presence of a population of massive stars. Measurements of molecular hydrogen lines demonstrate that this gas is also photoexcited, in contrast with previous studies. Models of the gas excitation in star-forming regions are constructed and comparison of the predicted line intensities with observations yields information regarding the gas density and structure of the complexes. The ionized gas in the archetypal starburst galaxy M82 is examined in greater detail through measurements made in mm-wavelength recombination lines (H40 and H53 alpha). These observations avoid the problems which occur when shorterwavelength lines are employed since they are unaffected by dust attenuation. The ionization state of the gas and the total luminosity are used to infer the range of stellar masses present in this galaxy. This range may be very narrow. Dissert. Abstr. N91-10815 Alabama Univ., Huntsville. Avail: Univ. Microfilms Order No. DA9015924 The inflationary period is modeled by generating a cosmological function, lambda(t), that depends on a period of exponential growth followed by a period of exponential decay. The model is equivalent to a single thermodynamic phase change and exhibits all the required features of an inflationary period such as exponential growth of the scale factor plus a natural relaxation (graceful exit) of lambda to the present day cosmological constant. After constraining the model to conditions imposed, by the inflationary hypothesis, a numerical computation is performed over the time period from the Planck time to the beginning of the radiation era. As a result of the constraints on the model, the presence of a very large negative Planckian cosmological constant was found. It was also found that the present-day value of this function, albeit small, is nevertheless positive. Using this model, the growth of the cosmological scale factor R(lambda) was found as a parameterized function of the cosmological function. It is shown that the numerical integration is greatly simplified if the multivalued function is solved. Not only does this greatly simplify the calculation, it shows that the parameterization of the scale factor in terms of the cosmological function is useful. Results are presented in a series of graphs. How the model could be related to either a Grand Unified theory or a quantum mechanical model of inflation in terms of the rate of production and decay of a (massive) X particle created by the initial instability of the vacuum at the planck time is discussed. It is further suggested that the cosmological function provides direct information about the decay rate (and hence the mass) of this X particle. Dissert. Abstr. N91-10816*# National Aeronautics and Space Administration. |