Science.gov

Sample records for atmospheric phenomena

  1. Atmospheric phenomena before and during sunset

    NASA Astrophysics Data System (ADS)

    Menat, M.

    The atmospheric transmittance and the astronomical refraction for low-elevation trajectories are discussed and quantitatively developed. The results are used to describe and calculate some of the fascinating atmospheric phenomena occurring shortly before and during sunset, such as the diminishing apparent luminance of the sun, its shape during sunset, and the green flash.

  2. Polar Phenomena in Outer Planet Atmospheres

    NASA Astrophysics Data System (ADS)

    Orton, G.; Fletcher, L.; Yanamandra-Fisher, P.; Leyrat, C.; Greathouse, T.; Parrish, P.; Encrenaz, T.; Simon-Miller, A.

    2008-12-01

    Infrared observations of the polar regions of the outer planets have revealed similarities to the Earth's atmosphere and some new phenomena. The most dominant force which is apparent in time-dependent studies of the poles is seasonal radiative forcing, which was detected in Saturn's stratosphere as early as 1973. For Saturn, Uranus and Neptune, planets with substantial obliquities, the seasonally dependent changes are predictable and can be used to constrain abundances of optically active gases and the rate of restoration by stratospheric circulation. In the case of Neptune, recent evidence shows that the heating is sufficient to allow a "leak" from the reservoir of methane in the deep atmosphere into the polar stratosphere. New thermal images of Uranus show that the winter pole of Uranus which has only recently emerged fully from darkness is colder than when it was in the middle of winter when Voyager 2 visited, confirming the substantial seasonal phase delay associated with radiative heating and cooling models. Even Jupiter with its 3-degree obliquity shows clear evidence for seasonal forcing of temperatures in the upper troposphere and stratosphere. The second most prominent characteristic of the resolvable polar temperature fields in Jupiter and Saturn is the formation of polar vortices. Jupiter's polar vortices are cold, similar to those detected in the terrestrial planets; they have sharp equatorward boundaries which are characterized by Rossby waves which rotate at the speed of the local zonal wind flow and are coincident with the similarly irregular boundaries of a polar haze, also known as "polar hoods". The cold vortex at Saturn's northern winter pole is muted, but Saturn also has a unique "warm polar vortex" in the south (late summer) pole which shows no apparent wave structure. Saturn's warm polar vortex has no counterpart in the Earth's atmosphere, where summer radiative warming simply dissipates the cold winter vortex. Saturn also possesses

  3. Auroral Phenomena in Brown Dwarf Atmospheres

    NASA Astrophysics Data System (ADS)

    Pineda, J. Sebastian; Hallinan, Gregg

    2016-01-01

    Since the unexpected discovery of radio emission from brown dwarfs some 15 years ago, investigations into the nature of this emission have revealed that, despite their cool and neutral atmospheres, brown dwarfs harbor strong kG magnetic fields, but unlike the warmer stellar objects, they generate highly circularly polarized auroral radio emission, like the giant planets of the Solar System. Our recent results from Keck LRIS monitoring of the brown dwarf LSR1835+32 definitively confirm this picture by connecting the auroral radio emission to spectroscopic variability at optical wavelengths as coherent manifestations of strong large-scale magnetospheric auroral current systems. I present some of the results of my dissertation work to understand the nature brown dwarf auroral phenomena. My efforts include a survey of Late L dwarfs and T dwarfs, looking for auroral Hα emission and a concurrent survey looking for the auroral emission of H3+ from brown dwarfs with radio pulse detections. I discuss the potential connection of this auroral activity to brown dwarf weather phenomena and how brown dwarf aurorae may differ from the analogous emission of the magnetized giant planets in the Solar System.

  4. Numerical analysis and modeling of atmospheric phenomena

    NASA Technical Reports Server (NTRS)

    Stone, Peter H.

    1994-01-01

    For the past 22 years Grant NGR 22-009-727 has been supporting research in the Center for Meteorology and Physical Oceanography (and its predecessors) in a wide variety of diagnostic and modeling studies of atmospheric and ocean phenomena. Professor Jule Charney was the initial Principal Investigator. Professor Peter Stone joined him as co-Principal Investigator in 1975 and became the sole Principal Investigator in 1981. During its lifetime the Grant has supported in whole or in part 11 Master's theses, 14 Ph.D. theses, and 45 papers published in refereed scientific journals. All of these theses and papers (with bibliographic references) are listed below. All but one of the theses were used to fulfill the requirements for MIT (Massachusetts Institute of Technology) degrees and are available from the MIT libraries. The one exception is F. Chen's Ph.D. thesis which was for a Harvard degree and is available from the Harvard libraries. In addition to the work described in the citations listed below, the Grant has supported Research Assistant Amy Solomon during the past two years to carry out a study of how baroclinic adjustment is affected by vertical resolution, vertical temperature structure, and dissipation. Ms. Solomon plans to use this project for her Ph.D. thesis. Support for this project will continue under NASA Grant NAG 5-2490, 'The Factors Controlling Poleward Heat Transport in Climate Models.'

  5. Oscillatory phenomena in solar and stellar atmospheres

    NASA Astrophysics Data System (ADS)

    Bloomfield, David Shaun

    This thesis presents varying studies into the nature of intensity oscillations observed both on the Sun and two active cool stars. The first part concentrates on the detection of correlated oscillations occuring between differing heights in the solar atmosphere above quiet-Sun magnetic network bright points (NBPs), interpreted as signatures of energy propagation. This is achieved through correlating in time the wavelet power spectra of lightcurves from images obtained in several optical wavelengths. In four of the eleven NBPs studied, evidence is found for upwardly-propagating, low-frequency waves (1.4 mHz, 2.1 mHz) in the lower chromosphere, decreasing in oscillatory power with the onset, or increase in power, of higher-frequency waves (2.9 mHz, 4.0 mHz) within the upper chromosphere. Moving higher into the atmosphere two of the four cases of higher frequency waves also show a decrease in power. These observational detections are interpreted as transverse-mode magnetohydrodynamic (MHD) waves undergoing non-linear mode coupling to longitudinal-modes at double the frequency, which shock or otherwise dissipate in the high chromosphere. Evidence is also found for additional upward- and downward- directed waves within all the NBPs studied. The extension of wavelet power techniques into the analysis of phase difference and phase coherence is also presented, utilising UV intensities obtained from above a weak solar network element. The problems associated with the quantification of phase coherence values are outlined and a comparison of two differing methods is carried out. Changes observed in the evolution of phase difference between oscillations detected in the UV emission of the temperature minimum and low transition region are shown to be due to the alteration of the underlying magnetic topology, occuring when same polarity flux emerges nearby. The final part of this thesis concerns the differing situation of intensity variations during energetic flare phenomena on

  6. Polarimetic Study of Atmospheric Phenomena and Its Applications

    NASA Astrophysics Data System (ADS)

    Yanamandra-Fisher, P. A.

    2015-12-01

    Polarized light occurs in three states: unpolarized, linear and circularized. Each mode of polarized light provides information about the scattering medium, from atmospheres to search for signatures of habitability. Linear polarization in the optical and near-infrared windows are optimum to study changes in cloud/hazes in planetary atmospheres. Circular polarization is important to understand the influence of multiple scattering in the atmosphere. Linear and circular polarization of comets provides information about the composition and wavelength dependence of the dust, indicative of new, active comets vs. older comets. Changes in magnetic fields (as in aurorae) can be explored with polarimetry. Atmospheric phenomena such as rainbows,clouds and haloes exhibit polarimetric signatures that can be used as diagnostics to probe the atmosphere and may be possible to extend this approach to other planets and exoplanets. Biological molecules exhibit an inherent handedness or circular polarization or chirality, assisting in search for the identification of astrobiological material in the solar system. I shall highlight observations and models for these phenomena.

  7. Science of atmospheric phenomena with JEM-EUSO

    NASA Astrophysics Data System (ADS)

    Adams, J. H.; Ahmad, S.; Albert, J.-N.; Allard, D.; Anchordoqui, L.; Andreev, V.; Anzalone, A.; Arai, Y.; Asano, K.; Ave Pernas, M.; Baragatti, P.; Barrillon, P.; Batsch, T.; Bayer, J.; Bechini, R.; Belenguer, T.; Bellotti, R.; Belov, K.; Berlind, A. A.; Bertaina, M.; Biermann, P. L.; Biktemerova, S.; Blaksley, C.; Blanc, N.; Błȩcki, J.; Blin-Bondil, S.; Blümer, J.; Bobik, P.; Bogomilov, M.; Bonamente, M.; Briggs, M. S.; Briz, S.; Bruno, A.; Cafagna, F.; Campana, D.; Capdevielle, J.-N.; Caruso, R.; Casolino, M.; Cassardo, C.; Castellinic, G.; Catalano, C.; Catalano, G.; Cellino, A.; Chikawa, M.; Christl, M. J.; Cline, D.; Connaughton, V.; Conti, L.; Cordero, G.; Crawford, H. J.; Cremonini, R.; Csorna, S.; Dagoret-Campagne, S.; de Castro, A. J.; De Donato, C.; de la Taille, C.; De Santis, C.; del Peral, L.; Dell'Oro, A.; De Simone, N.; Di Martino, M.; Distratis, G.; Dulucq, F.; Dupieux, M.; Ebersoldt, A.; Ebisuzaki, T.; Engel, R.; Falk, S.; Fang, K.; Fenu, F.; Fernández-Gómez, I.; Ferrarese, S.; Finco, D.; Flamini, M.; Fornaro, C.; Franceschi, A.; Fujimoto, J.; Fukushima, M.; Galeotti, P.; Garipov, G.; Geary, J.; Gelmini, G.; Giraudo, G.; Gonchar, M.; González Alvarado, C.; Gorodetzky, P.; Guarino, F.; Guzmán, A.; Hachisu, Y.; Harlov, B.; Haungs, A.; Hernández Carretero, J.; Higashide, K.; Ikeda, D.; Ikeda, H.; Inoue, N.; Inoue, S.; Insolia, A.; Isgrò, F.; Itow, Y.; Joven, E.; Judd, E. G.; Jung, A.; Kajino, F.; Kajino, T.; Kaneko, I.; Karadzhov, Y.; Karczmarczyk, J.; Karus, M.; Katahira, K.; Kawai, K.; Kawasaki, Y.; Keilhauer, B.; Khrenov, B. A.; Kim, J.-S.; Kim, S.-W.; Kim, S.-W.; Kleifges, M.; Klimov, P. A.; Kolev, D.; Kreykenbohm, I.; Kudela, K.; Kurihara, Y.; Kusenko, A.; Kuznetsov, E.; Lacombe, M.; Lachaud, C.; Lee, J.; Licandro, J.; Lim, H.; López, F.; Maccarone, M. C.; Mannheim, K.; Maravilla, D.; Marcelli, L.; Marini, A.; Martinez, O.; Masciantonio, G.; Mase, K.; Matev, R.; Medina-Tanco, G.; Mernik, T.; Miyamoto, H.; Miyazaki, Y.; Mizumoto, Y.; Modestino, G.; Monaco, A.; Monnier-Ragaigne, D.; Morales de los Ríos, J. A.; Moretto, C.; Morozenko, V. S.; Mot, B.; Murakami, T.; Murakami, M. Nagano; Nagata, M.; Nagataki, S.; Nakamura, T.; Napolitano, T.; Naumov, D.; Nava, R.; Neronov, A.; Nomoto, K.; Nonaka, T.; Ogawa, T.; Ogio, S.; Ohmori, H.; Olinto, A. V.; Orleański, P.; Osteria, G.; Panasyuk, M. I.; Parizot, E.; Park, I. H.; Park, H. W.; Pastircak, B.; Patzak, T.; Paul, T.; Pennypacker, C.; Perez Cano, S.; Peter, T.; Picozza, P.; Pierog, T.; Piotrowski, L. W.; Piraino, S.; Plebaniak, Z.; Pollini, A.; Prat, P.; Prévôt, G.; Prieto, H.; Putis, M.; Reardon, P.; Reyes, M.; Ricci, M.; Rodríguez, I.; Rodríguez Frías, M. D.; Ronga, F.; Roth, M.; Rothkaehl, H.; Roudil, G.; Rusinov, I.; Rybczyński, M.; Sabau, M. D.; Sáez-Cano, G.; Sagawa, H.; Saito, A.; Sakaki, N.; Sakata, M.; Salazar, H.; Sánchez, S.; Santangelo, A.; Santiago Crúz, L.; Sanz Palomino, M.; Saprykin, O.; Sarazin, F.; Sato, H.; Sato, M.; Schanz, T.; Schieler, H.; Scotti, V.; Segreto, A.; Selmane, S.; Semikoz, D.; Serra, M.; Sharakin, S.; Shibata, T.; Shimizu, H. M.; Shinozaki, K.; Shirahama, T.; Siemieniec-Oziȩbło, G.; Silva López, H. H.; Sledd, J.; Słomińska, K.; Sobey, A.; Sugiyama, T.; Supanitsky, D.; Suzuki, M.; Szabelska, B.; Szabelski, J.; Tajima, F.; Tajima, N.; Tajima, T.; Takahashi, Y.; Takami, H.; Takeda, M.; Takizawa, Y.; Tenzer, C.; Tibolla, O.; Tkachev, L.; Tokuno, H.; Tomida, T.; Tone, N.; Toscano, S.; Trillaud, F.; Tsenov, R.; Tsunesada, Y.; Tsuno, K.; Tymieniecka, T.; Uchihori, Y.; Unger, M.; Vaduvescu, O.; Valdés-Galicia, J. F.; Vallania, P.; Valore, L.; Vankova, G.; Vigorito, C.; Villaseñor, L.; von Ballmoos, P.; Wada, S.; Watanabe, J.; Watanabe, S.; Watts, J.; Weber, M.; Weiler, T. J.; Wibig, T.; Wiencke, L.; Wille, M.; Wilms, J.; Włodarczyk, Z.; Yamamoto, T.; Yamamoto, Y.; Yang, J.; Yano, H.; Yashin, I. V.; Yonetoku, D.; Yoshida, K.; Yoshida, S.; Young, R.; Zotov, M. Yu.; Zuccaro Marchi, A.; Słomiński, J.

    2015-11-01

    The main goal of the JEM-EUSO experiment is the study of Ultra High Energy Cosmic Rays (UHECR, 1019-1021 e V), but the method which will be used (detection of the secondary light emissions induced by cosmic rays in the atmosphere) allows to study other luminous phenomena. The UHECRs will be detected through the measurement of the emission in the range between 290 and 430 m, where some part of Transient Luminous Events (TLEs) emission also appears. This work discusses the possibility of using the JEM-EUSO Telescope to get new scientific results on TLEs. The high time resolution of this instrument allows to observe the evolution of TLEs with great precision just at the moment of their origin. The paper consists of four parts: review of the present knowledge on the TLE, presentation of the results of the simulations of the TLE images in the JEM-EUSO telescope, results of the Russian experiment Tatiana-2 and discussion of the possible progress achievable in this field with JEM-EUSO as well as possible cooperation with other space projects devoted to the study of TLE - TARANIS and ASIM. In atmospheric physics, the study of TLEs became one of the main physical subjects of interest after their discovery in 1989. In the years 1992 - 1994 detection was performed from satellite, aircraft and space shuttle and recently from the International Space Station. These events have short duration (milliseconds) and small scales (km to tens of km) and appear at altitudes 50 - 100 km. Their nature is still not clear and each new experimental data can be useful for a better understanding of these mysterious phenomena.

  8. Simulation of nonstationary phenomena in atmospheric-pressure glow discharge

    NASA Astrophysics Data System (ADS)

    Korolev, Yu. D.; Frants, O. B.; Nekhoroshev, V. O.; Suslov, A. I.; Kas'yanov, V. S.; Shemyakin, I. A.; Bolotov, A. V.

    2016-06-01

    Nonstationary processes in atmospheric-pressure glow discharge manifest themselves in spontaneous transitions from the normal glow discharge into a spark. In the experiments, both so-called completed transitions in which a highly conductive constricted channel arises and incomplete transitions accompanied by the formation of a diffuse channel are observed. A model of the positive column of a discharge in air is elaborated that allows one to interpret specific features of the discharge both in the stationary stage and during its transition into a spark and makes it possible to calculate the characteristic oscillatory current waveforms for completed transitions into a spark and aperiodic ones for incomplete transitions. The calculated parameters of the positive column in the glow discharge mode agree well with experiment. Data on the densities of the most abundant species generated in the discharge (such as atomic oxygen, metastable nitrogen molecules, ozone, nitrogen oxides, and negative oxygen ions) are presented.

  9. Phenomena of oscillations in atmospheric pressure direct current glow discharges

    SciTech Connect

    Liu, Fu-cheng; Yan, Wen; Wang, De-zhen

    2013-12-15

    Self-sustained oscillations in a dc glow discharge with a semiconductor layer at atmospheric pressure were investigated by means of a one-dimensional fluid model. It is found that the dc glow discharge initially becomes unstable in the subnormal glow region and gives rise to oscillations of plasma parameters. A variety of oscillations with one or more frequencies have been observed under different conditions. The discharge oscillates between the glow discharge mode and the Townsend discharge mode in the oscillations with large amplitude while operates in the subnormal glow discharge mode all the while in the oscillations with small amplitude. Fourier Transform spectra of oscillations reveal the transition mechanism between different oscillations. The effects of semiconductor conductivity on the oscillation frequency of the dominant mode, gas voltage, as well as the discharge current have also been analyzed.

  10. Fleets of enduring drones to probe atmospheric phenomena with clouds

    NASA Astrophysics Data System (ADS)

    Lacroix, Simon; Roberts, Greg; Benard, Emmanuel; Bronz, Murat; Burnet, Frédéric; Bouhoubeiny, Elkhedim; Condomines, Jean-Philippe; Doll, Carsten; Hattenberger, Gautier; Lamraoui, Fayçal; Renzaglia, Alessandro; Reymann, Christophe

    2016-04-01

    A full spatio-temporal four-dimensional characterization of the microphysics and dynamics of cloud formation including the onset of precipitation has never been reached. Such a characterization would yield a better understanding of clouds, e.g. to assess the dominant mixing mechanism and the main source of cloudy updraft dilution. It is the sampling strategy that matters: fully characterizing the evolution over time of the various parameters (P, T, 3D wind, liquid water content, aerosols...) within a cloud volume requires dense spatial sampling for durations of the order of one hour. A fleet of autonomous lightweight UAVs that coordinate themselves in real-time as an intelligent network can fulfill this purpose. The SkyScanner project targets the development of a fleet of autonomous UAVs to adaptively sample cumuli, so as to provide relevant data to address long standing questions in atmospheric science. It mixes basic researches and experimental developments, and gathers scientists in UAV conception, in optimal flight control, in intelligent cooperative behaviors, and of course atmospheric scientists. Two directions of researches are explored: optimal UAV conception and control, and optimal control of a fleet of UAVs. The design of UAVs for atmospheric science involves the satisfaction of trade-offs between payload, endurance, ease of deployment... A rational conception scheme that integrates the constraints to optimize a series of criteria, in particular energy consumption, would yield the definition of efficient UAVs. This requires a fine modeling of each involved sub-system and phenomenon, from the motor/propeller efficiency to the aerodynamics at small scale, including the flight control algorithms. The definition of mission profiles is also essential, considering the aerodynamics of clouds, to allow energy harvesting schemes that exploit thermals or gusts. The conception also integrates specific sensors, in particular wind sensor, for which classic

  11. Wave phenomena comparison between Mars and Titan upper atmospheres

    NASA Astrophysics Data System (ADS)

    Elrod, Meredith K.; Bell, J. M.

    2013-10-01

    We will examine the presence of waves in the neutral atmospheres of two terrestrial bodies: Mars and Titan. We will examine the aerobraking datasets from both the Mars Global Surveyor (MGS) and Mars Odyssey (ODY) missions, analyzing the neutral densities to characterize the planetary tides and/or smaller-scale internal gravity waves present in the data. While several studies have examined these features before at Mars (e.g., Forbes et al. [2002] and Fritts and Tolson [2006]), we will be focusing on examining whether or not the wave features observed in the thermosphere could be explained primarily with planetary tides, as posted recently in Klienbohl et al. [2013]. In addition to this, we will also examine the neutral densities obtained by the Cassini Ion-Neutral Mass Spectrometer (INMS) in order to determine if planetary tides can explain the numerous wave-like features that have been interpreted as gravity waves propagating vertically (cf., Mueller-Wodarg et al. [2008], Cui et al. [2013], and Snowden et al. [2013]).

  12. To investigate or not to investigate? Researchers' views on unexplored atmospheric light phenomena

    NASA Astrophysics Data System (ADS)

    Caron, Etienne; Faridi, Pouya

    2016-02-01

    For hundreds of years, scientists have been studying light, which is used nowadays to explore the universe and cure diseases. Here, we present the results of a survey indicating a significant support from a subset of the academic community to investigate rare, unusual and unexplained atmospheric light phenomena that have historically been unexplored by scientists — the transient luminous phenomena in the valley of Hessdalen in Norway in particular. We propose that stable, long-term funding, and thorough investigation of poorly understood and/or unexplored luminous phenomena occurring in the low atmosphere could lead to the creation of new inter-disciplinary research programs in multiple universities, and ultimately, to important fundamental discoveries in the field of atmospheric science, photonics and beyond.

  13. Atmospheric Manmade Glowings Phenomena Observed During the Launches of Solid Propellant Rockets

    NASA Astrophysics Data System (ADS)

    Chernouss, S. A.; Platov, V. V.; Upspensky, M. V.; Alpatov, V. V.; Kirillov, A. S.

    2015-09-01

    Exotic types of luminosities observed in the upper atmosphere always take place during the launch and flight of solid-propellant rockets We consider a large-scale geometry and dynamic features of such phenomena also physics of the intense turquoise (blue-green) glow observed in twilight conditions in the region of missile flight. This study has been based on numerous observations of different rocket flights in the atmosphere over Russia and Scandinavia. Formation of the monoxide aluminum clouds observed in the upper atmosphere is a result of interaction of the exhausted propellant products with the atomic oxygen. The sunlight excited the monoxide aluminum EA1O*) resonance emissions in the atmosphere. Careful studies of spectra of the manmade luminosities during rocket launch/flight permit us to know chemical, thermal and mechanical processes in the atmosphere similar as it is doing in experiments with the artificial cloud release from sounding rockets in the high latitude atmosphere.

  14. A Study of the Effects of Atmospheric Phenomena on Mars Science Laboratory Entry Performance

    NASA Technical Reports Server (NTRS)

    Cianciolo, Alicia D.; Way, David W.; Powell, Richard W.

    2008-01-01

    At Earth during entry the shuttle has experienced what has come to be known as potholes in the sky or regions of the atmosphere where the density changes suddenly. Because of the small data set of atmospheric information where the Mars Science Laboratory (MSL) parachute deploys, the purpose of this study is to examine the effect similar atmospheric pothole characteristics, should they exist at Mars, would have on MSL entry performance. The study considers the sensitivity of entry design metrics, including altitude and range error at parachute deploy and propellant use, to pothole like density and wind phenomena.

  15. Electric currents induced inside biological cells by geomagnetic and atmospheric phenomena.

    PubMed

    Durand-Manterola, H J; Mendoza, B; Diaz-Sandoval, R

    2001-01-01

    An increasing number of studies have appeared in the last ten years indicating that some pathologies may correlate with geomagnetic activity and cosmic rays. However a physical mechanism binding both phenomena has not been proposed. In the present work we obtain the amplitude of the magnetic fields at different frequencies, that may induce inside biological cells currents of the same magnitude of the currents generated by the cells themselves. We compare these values with the wave amplitudes produced in geomagnetic and atmospheric phenomena, and found that micropulsations, whistlers and lightning are capable of produce the same or larger values. PMID:11803972

  16. The Atmospheric Scanning Electron Microscope with open sample space observes dynamic phenomena in liquid or gas.

    PubMed

    Suga, Mitsuo; Nishiyama, Hidetoshi; Konyuba, Yuji; Iwamatsu, Shinnosuke; Watanabe, Yoshiyuki; Yoshiura, Chie; Ueda, Takumi; Sato, Chikara

    2011-12-01

    Although conventional electron microscopy (EM) requires samples to be in vacuum, most chemical and physical reactions occur in liquid or gas. The Atmospheric Scanning Electron Microscope (ASEM) can observe dynamic phenomena in liquid or gas under atmospheric pressure in real time. An electron-permeable window made of pressure-resistant 100 nm-thick silicon nitride (SiN) film, set into the bottom of the open ASEM sample dish, allows an electron beam to be projected from underneath the sample. A detector positioned below captures backscattered electrons. Using the ASEM, we observed the radiation-induced self-organization process of particles, as well as phenomena accompanying volume change, including evaporation-induced crystallization. Using the electrochemical ASEM dish, we observed tree-like electrochemical depositions on the cathode. In silver nitrate solution, we observed silver depositions near the cathode forming incidental internal voids. The heated ASEM dish allowed observation of patterns of contrast in melting and solidifying solder. Finally, to demonstrate its applicability for monitoring and control of industrial processes, silver paste and solder paste were examined at high throughput. High resolution, imaging speed, flexibility, adaptability, and ease of use facilitate the observation of previously difficult-to-image phenomena, and make the ASEM applicable to various fields. PMID:22088441

  17. Atmospheric Electric Field Measurements at 100 Hz and High Frequency Electric Phenomena

    NASA Astrophysics Data System (ADS)

    Conceição, Ricardo; Gonçalves da Silva, Hugo; Matthews, James; Bennett, Alec; Chubb, John

    2016-04-01

    Spectral response of Atmospheric Electric Potential Gradient (PG), symmetric to the Atmospheric Electric Field, gives important information about phenomena affecting these measurements with characteristic time-scales that appear in the spectra as specific periodicities. This is the case of urban pollution that has a clear weekly dependence and reveals itself on PG measurements by a ~7 day periodicity (Silva et al., 2014). While long-term time-scales (low frequencies) have been exhaustively explored in literature, short-term time-scales (high frequencies), above 1 Hz, have comparatively received much less attention (Anisimov et al., 1999). This is mainly because of the technical difficulties related with the storage of such a huge amount of data (for 100 Hz sampling two days of data uses a ~1 Gb file) and the response degradation of the field-meters at such frequencies. Nevertheless, important Electric Phenomena occurs for frequencies above 1 Hz that are worth pursuing, e.g. the Schumann Resonances have a signature of worldwide thunderstorm activity at frequencies that go from ~8 up to ~40 Hz. To that end the present work shows preliminary results on PG measurements at 100 Hz that took place on two clear-sky days (17th and 18th June 2015) on the South of Portugal, Évora (38.50° N, 7.91° W). The field-mill used is a JCI 131F installed in the University of Évora campus (at 2 m height) with a few trees and two buildings in its surroundings (~50 m away). This device was developed by John Chubb (Chubb, 2014) and manufactured by Chilworth (UK). It was calibrated in December 2013 and recent work by the author (who is honored in this study for his overwhelming contribution to atmospheric electricity) reveals basically a flat spectral response of the device up to frequencies of 100 Hz (Chubb, 2015). This makes this device suitable for the study of High Frequency Electric Phenomena. Anisimov, S.V., et al. (1999). On the generation and evolution of aeroelectric structures

  18. Determination of constant-volume balloon capabilities for aeronautical research. [specifically measurement of atmospheric phenomena

    NASA Technical Reports Server (NTRS)

    Tatom, F. B.; King, R. L.

    1977-01-01

    The proper application of constant-volume balloons (CVB) for measurement of atmospheric phenomena was determined. And with the proper interpretation of the resulting data. A literature survey covering 176 references is included. the governing equations describing the three-dimensional motion of a CVB immersed in a flow field are developed. The flowfield model is periodic, three-dimensional, and nonhomogeneous, with mean translational motion. The balloon motion and flow field equations are cast into dimensionless form for greater generality, and certain significant dimensionless groups are identified. An alternate treatment of the balloon motion, based on first-order perturbation analysis, is also presented. A description of the digital computer program, BALLOON, used for numerically integrating the governing equations is provided.

  19. Invited papers from the International Symposium on Nonequilibrium Processes, Plasma, Combustion and Atmospheric Phenomena

    NASA Astrophysics Data System (ADS)

    Starik, Alexander M.

    2013-11-01

    The International Symposium on Nonequilibrium Processes, Plasma, Combustion and Atmospheric Phenomena is a forum of international experts in such fundamental areas as physical and chemical kinetics, physics of low temperature and cluster plasmas, physics of shock and detonation waves, physics and chemistry of aerosols and nanoparticles, combustion and atmospheric chemistry, physics and chemistry of high speed flows, plasma and laser chemistry, plasma, laser and combustion assisted technologies. This symposium has already become a notable biannual event attracting a growing attendance of scientists from all over the world. The first symposium was organizing in St Petersburg, Russia, 8-11 July 2003, and was dedicated to the memory of N N Semenov, a founder of the chain-branching reaction theory and a Nobel prizewinner. The second, third and fourth symposia were held in Sochi, Russia, 3-7 October 2005; 25-29 June 2007; and 5-9 October 2009. The last (fifth) symposium was also organized in Sochi, Russia, 1-6 October 2012. Here we present selected proceedings of the last symposium, comprised of four invited papers on the topics of ab initio studies of some elementary processes important for atmospheric plasma and combustion, kinetics of low temperature plasma and physics of clusters. The papers have been written by the symposium participants and are based on their reports at the meeting. They are: 'Thermochemistry of small iodine species' by Šulková et al ; 'Analysis of the reaction and quenching channels in a H + O2(a 1Δg ) system' by Sharipov and Starik; 'Kinetics of plasmachemical processes in the expanding flow of nitrogen plasma' by Kadochnikov et al ; and 'Theoretical study of structure and physical properties of (Al2O3)n clusters' by Sharipov et al.

  20. Atmospheric tides and other relationships: ``Interpreting the Phenomena'' at the time of the Seeberg conference

    NASA Astrophysics Data System (ADS)

    Kokott, Wolfgang

    research. The Seeberg conference took place in an environment of (prolonged) change from natural history to modern science. In astronomy, the interaction between descriptive, phenomenological methods and quantitative investigations and results was particularly fruitful. Many of the results did emerge slowly: Seemingly atmospheric phenomena, like meteors, did turn out to be of extraterrestrial origin; objects like ejecta from lunar volcanoes eventually became mere figments of imagination. In both cases, unprejudiced observations and their theoretical evaluation were necessary. Chladni's work (1794) on the origin of meteorites did need to be verified by the ``stone shower'' of l'Aigle (1803). And the quest for the missing planet between Mars and Jupiter did not only produce literally many results - it also led to the ``Theoria Motus''.

  1. A new South American network to study the atmospheric electric field and its variations related to geophysical phenomena

    NASA Astrophysics Data System (ADS)

    Tacza, J.; Raulin, J.-P.; Macotela, E.; Norabuena, E.; Fernandez, G.; Correia, E.; Rycroft, M. J.; Harrison, R. G.

    2014-12-01

    In this paper we present the capability of a new network of field mill sensors to monitor the atmospheric electric field at various locations in South America; we also show some early results. The main objective of the new network is to obtain the characteristic Universal Time diurnal curve of the atmospheric electric field in fair weather, known as the Carnegie curve. The Carnegie curve is closely related to the current sources flowing in the Global Atmospheric Electric Circuit so that another goal is the study of this relationship on various time scales (transient/monthly/seasonal/annual). Also, by operating this new network, we may also study departures of the Carnegie curve from its long term average value related to various solar, geophysical and atmospheric phenomena such as the solar cycle, solar flares and energetic charged particles, galactic cosmic rays, seismic activity and specific meteorological events. We then expect to have a better understanding of the influence of these phenomena on the Global Atmospheric Electric Circuit and its time-varying behavior.

  2. Dynamic phenomena in the Earth's atmosphere during January-May 1994

    NASA Astrophysics Data System (ADS)

    Makhmutov, Vladimir; Svirzhevskaya, Albina; Svirzhevsky, Nikolai; Stozhkov, Yuri; Bazilevskaya, Galina

    The long-term measurements of cosmic ray fluxes in the atmosphere by radiosound-detector are carried out by the Lebedev Physical Institute RAS since 1957 till now at several geomagnetic locations including northern and southern polar regions and mid latitudes. We concentrate on energetic electron precipitation events observed in the Earth’s polar atmosphere in January-May 1994. During this time very extended transequatorial coronal holes were observed at the Sun. They produced the high-speed solar wind streams which caused the recurrent interplanetary disturbances and geomagnetic storms. We present the energetic and temporal characteristics of precipitating electron events recorded in the atmosphere during this period. We discuss the origin of these events and their relation to the interplanetary and geomagnetic disturbances.

  3. Investigation of chemical properties and transport phenomena associated with pollutants in the atmospheric boundary layer

    NASA Astrophysics Data System (ADS)

    Holmes, Heather A.

    Under the Clean Air Act, the U.S. Environmental Protection Agency is required to determine which air pollutants are harmful to human health, then regulate, monitor and establish criteria levels for these pollutants. To accomplish this and for scientific advancement, integration of knowledge from several disciplines is required including: engineering, atmospheric science, chemistry and public health. Recently, a shift has been made to establish interdisciplinary research groups to better understand the atmospheric processes that govern the transport of pollutants and chemical reactions of species in the atmospheric boundary layer (ABL). The primary reason for interdisciplinary collaboration is the need for atmospheric processes to be treated as a coupled system, and to design experiments that measure meteorological, chemical and physical variables simultaneously so forecasting models can be improved (i.e., meteorological and chemical process models). This dissertation focuses on integrating research disciplines to provide a more complete framework to study pollutants in the ABL. For example, chemical characterization of particulate matter (PM) and the physical processes governing PM distribution and mixing are combined to provide more comprehensive data for source apportionment. Data from three field experiments were utilized to study turbulence, meteorological and chemical parameters in the ABL. Two air quality field studies were conducted on the U.S./Mexico border. The first was located in Yuma, AZ to investigate the spatial and temporal variability of PM in an urban environment and relate chemical properties of ambient aerosols to physical findings. The second border air quality study was conducted in Nogales, Sonora, Mexico to investigate the relationship between indoor and outdoor air quality in order to better correlate cooking fuel types and home activities to elevated indoor PM concentrations. The final study was executed in southern Idaho and focused on

  4. Observations of multiple stationary striation phenomena in an atmospheric pressure neon plasma jet

    NASA Astrophysics Data System (ADS)

    Fujiwara, Yutaka; Sakakita, Hajime; Yamada, Hiromasa; Yamagishi, Yusuke; Itagaki, Hirotomo; Kiyama, Satoru; Fujiwara, Masanori; Ikehara, Yuzuru; Kim, Jaeho

    2016-01-01

    The formation of multiple stationary striations between a nozzle exit and a conductive target plate was clearly observed at regular intervals using a digital camera along an atmospheric pressure plasma jet of dielectric barrier discharge using a neon gas into ambient air. From the results of measuring using a high-speed camera during the positive current phase, the emission initially started in the middle between the nozzle and the target, and striations progressed in both upward and downward directions. During the negative current phase, the emission initially started in a region near the target, and the striations rapidly progressed to the nozzle.

  5. Waves, shocks and non-stationary phenomena in the outer solar atmosphere

    NASA Technical Reports Server (NTRS)

    Hansteen, V. H.

    1997-01-01

    The dynamics of the solar chromosphere, transition region and corona were investigated. The consequences of the solar dynamics on the formation of spectral features in solar atmosphere regions are discussed. Data mainly from the solar ultraviolet measurement of emitted radiation (SUMER) instrument, showing signatures of non-stationary processes, are presented. These data are compared to the predictions of numerical models of the chromosphere and transition region. The observations seem to support the importance of upwardly propagating acoustic shocks in the heating of the chromosphere.

  6. Mars atmospheric phenomena during major dust storms, as measured at surface

    NASA Technical Reports Server (NTRS)

    Ryan, J. A.; Henry, R. M.

    1979-01-01

    Meteorological instrumentation aboard the Viking Mars Landers measures wind, temperature, and pressure. Two global dust storms occurred during northern autumn and winter, observed both by the orbiters and by the landers. The meteorological data from the landers has been analyzed for the period just before first storm arrival to just after second storm arrival, with the objectives of defining the meteorological phenomena during the storm period, determining those associated with storm and dust arrival, and evaluating the effects on synoptic conditions and the general circulation. Times of dust arrival over the sites could be defined fairly closely from optical and pressure (solar tide) data, and dust arrival was also accompanied by changes in diurnal temperature range, temperature maxima, and temperature minima. The arrivals of the storms at Viking Lander 1 were accompanied by significant increases in wind speed and pressure. No such changes were observed at Viking Lander 2. It is possible that surface material could have been raised locally at Viking Lander 1. Throughout the period except for the time following the second dust storm the synoptic picture at Viking Lander 2 was one of eastward moving cyclonic and anticyclonic systems. These disappeared following the second storm, a phenomenon which may be related to the storm.

  7. Three-dimensional numerical modelling of gas discharges at atmospheric pressure incorporating photoionization phenomena

    NASA Astrophysics Data System (ADS)

    Papageorgiou, L.; Metaxas, A. C.; Georghiou, G. E.

    2011-02-01

    A three-dimensional (3D) numerical model for the characterization of gas discharges in air at atmospheric pressure incorporating photoionization through the solution of the Helmholtz equation is presented. Initially, comparisons with a two-dimensional (2D) axi-symmetric model are performed in order to assess the validity of the model. Subsequently several discharge instabilities (plasma spots and low pressure inhomogeneities) are considered in order to study their effect on streamer branching and off-axis propagation. Depending on the magnitude and position of the plasma spot, deformations and off-axis propagation of the main discharge channel were obtained. No tendency for branching in small (of the order of 0.1 cm) overvolted discharge gaps was observed.

  8. Atmospheric Phenomena Observed Over The South China Sea By The Advanced Synthetic Aperture Radar Onboard the ENVISAT Satellite

    NASA Astrophysics Data System (ADS)

    Alpers, Werner; Huang, Weigen; Chan, Pak Wai; Wong, Wai Kin; Cheng, Cho Ming; Mouche, Alexis

    2010-10-01

    Atmospheric phenomena often leave fingerprints on the sea surface, which are detectable by synthetic aperture radar (SAR). Here we present some representative examples of SAR images acquired by the Advanced Synthetic Aperture Radar (ASAR) onboard the Envisat satellite over the South China Sea (SCS) which show radar signatures of atmospheric gravity waves (AGWs) and of coastal wind fields. On SAR images of the SCS also often radar signatures of oceanic internal waves (OIWs) are visible which have similar spatial scales as the ones originating from AGWs. Therefore we first present criteria how to distinguish between them by analyzing the structure of the radar signatures. Then we present two examples of ASAR images which show radar signatures of AGWs over the SCS. Furthermore, we present a SAR image showing radar signatures of a northerly Winter Monsoon surge event over the coastal area south of Hong Kong and compare it with a cloud image and a weather radar image. From the ASAR image we retrieve the near-surface wind field and compare it with the wind field simulated by the AIR model of the Hong Kong Observatory. The comparison shows that the AIR model can simulate quite well the wind speed as well as the position and shape of the frontal line measured by ASAR.

  9. Simulation of ENSO-like phenomena with a low-resolution coupled GCM of the global ocean and atmosphere

    SciTech Connect

    Lau, Ngarcheung; Philander, S.G.H.; Nath, M.J. )

    1992-04-01

    A 140-year simulation of the ocean-atmosphere climate system has been performed by the GFDL Climate Dynamics Project using a low-resolution coupled general circulation model (GCM). The model was subjected to annually averaged insolation throughout the integration. This coupled system exhibits well-defined fluctuations in the tropical Pacific, with a preferred time scale of 3-4 years. The characteristics of these recurrent anomalies were examined by applying an extended empirical orthogonal function (EEOF) analysis to selected model variables. These results indicate that the simulated oscillations are accompanied by coherent changes in the atmospheric and oceanic circulation. The spatial patterns associated with the leading EEOF mode indicate that SST anomalies make their first appearance off the Peru-Ecuador coast and then migrate steadily westward, with an average transit time of 12-15 months. The arrival and eventual decay of SST fluctuations in the western Pacific is typically followed by the initiation of anomalies of the opposite polarity along the American coasts. The space-time evolution of various meteorological and oceanographic signals exhibits well-defined phase relationships with the SST perturbations. Some aspects of the model behavior during these warm and cold episodes are reminiscent of observed phenomena associated with the El Nino-Southern Oscillation (ENSO). Analysis of the climatological heat budget for the top ocean layer indicates a near balance between horizontal and vertical temperature advection by the time-mean flow, vertical diffusion, and heat input from the overlying atmosphere. The principal mechanisms associated with the simulated ENSO-like cycles were then studied by examining the local heat budget for the SST perturbations. The relative importance of various linear advective processes in the heat budget exhibits a notable dependence on geographical location and on the specific phase of the ENSO-like cycle.

  10. Transformation and birth processes of the transient luminous phenomena's in the low atmosphere of the Hessdalen valley, Norway.

    NASA Astrophysics Data System (ADS)

    Gitle Hauge, Bjørn; Strand, Erling

    2013-04-01

    Transient louminous phenomenas has been observed in and over the Hessdalen valley for over 100 years. These phenomena's has been nicknamed "Hessdalen phenomenas", HP, and has been under permanent scientific investigation since 1998, when Norwegian, Italian and later French researchers installed different types of monitoring equipment in the valley. The earth's magnetic field, electromagnetic radiation in different bands, radioactive radiation, electrical resistance in the ground, ultrasound, and seismic activity are some of the signals/parameters that has been monitored. The valley has also been surveillanced by radar, optical spectrometers and automatic video recording devices. So far no electromagnetic radiation, except in the optical band, has been detected that can be coupled to the HP. The phenomenon is characterized by its horizontal movement, intense optical radiation when a transformation process occurs, different colours where white/yellow dominates, no sound, high speed, unpredictable flight patterns, seen by radar while optical invisible and often observed with continuous optical spectrum. The phenomena have been seen touching ground, without leaving burning marks and flying in higher altitudes over the valley apparently ignoring wind/weather conditions. The Hessdalen valley is located in the middle of Norway and is famous for its mines with iron, zinc and copper ore. Big deposits of ore still reside inside the valley, and the mountains are penetrated by several mineshafts, some has depth down to 1000m. No exact birthplace has been located and the phenomenon seems to emerge "out of thin air" anywhere in the valley. Any activity coupled to mineshafts has not been observed. In September 2006 a birth and transformation process was observed and several optical spectrums was obtained. The phenomena appear as a big white light possibly not more than some hundred meters above the ground in a desolated area. The phenomenon starts a transformation process

  11. Future monitoring of charged particle energy deposition into the upper atmosphere and comments on possible relationships between atmospheric phenomena and solar and/or geomagnetic activity

    NASA Technical Reports Server (NTRS)

    Williams, D. J.; Grubb, R. N.; Evans, D. S.; Sauer, H. H.

    1975-01-01

    Monitoring of earth's atmosphere was conducted for several years utilizing the ITOS series of low-altitude, polar-orbiting weather satellites. A space environment monitoring package was included in these satellites to perform measurements of a portion of earth's charged particle environment. The charged particle observations proposed for the low-altitude weather satellite TIROS N, are described which will provide the capability of routine monitoring of the instantaneous total energy deposition into the upper atmosphere by the precipitation of charged particles from higher altitudes. Such observations may be of use in future studies of the relationships between geomagnetic activity and atmospheric weather pattern developments. Estimates are given to assess the potential importance of this type of energy deposition. Discussion and examples are presented illustrating the importance of distinguishing between solar and geomagnetic activity as possible causative sources. Such differentiation is necessary because of the widely different spatial and time scales involved in the atmospheric energy input resulting from these various sources of activity.

  12. Future monitoring of charged particle energy deposition into the upper atmosphere and comments on possible relationships between atmospheric phenomena and solar and/or geomagnetic activity

    NASA Technical Reports Server (NTRS)

    Williams, D. J.; Grubb, R. N.; Evans, D. S.; Sauer, H. H.

    1974-01-01

    The charged particle observations proposed for the new low altitude weather satellites, TIROS-N, are described that will provide the capability of routine monitoring of the instantaneous total energy deposition into the upper atmosphere by the precipitation of charged particles from higher altitudes. Estimates are given to assess the potential importance of this type of energy deposition. Discussion and examples are presented illustrating the importance in distinguishing between solar and geomagnetic activity as possible causative sources.

  13. Paranormal phenomena

    NASA Astrophysics Data System (ADS)

    Gaina, Alex

    1996-08-01

    Critical analysis is given of some paranormal phenomena events (UFO, healers, psychokinesis (telekinesis))reported in Moldova. It is argued that correct analysis of paranormal phenomena should be made in the framework of electromagnetism.

  14. Colloidal Phenomena.

    ERIC Educational Resources Information Center

    Russel, William B.; And Others

    1979-01-01

    Described is a graduate level engineering course offered at Princeton University in colloidal phenomena stressing the physical and dynamical side of colloid science. The course outline, reading list, and requirements are presented. (BT)

  15. Transport Phenomena.

    ERIC Educational Resources Information Center

    McCready, Mark J.; Leighton, David T.

    1987-01-01

    Discusses the problems created in graduate chemical engineering programs when students enter with a wide diversity of understandings of transport phenomena. Describes a two-semester graduate transport course sequence at the University of Notre Dame which focuses on fluid mechanics and heat and mass transfer. (TW)

  16. Atmospheric Misconceptions.

    ERIC Educational Resources Information Center

    Aron, Robert H.

    1994-01-01

    Presents student survey results (n=708) of misconceptions held regarding the atmosphere. Results indicated a basic lack of understanding concerning atmospheric processes and phenomena. Although misconceptions generally decreased with increasing education, some seemed to be firmly rooted. (PR)

  17. Crystallization phenomena in slags

    NASA Astrophysics Data System (ADS)

    Orrling, Carl Folke

    2000-09-01

    The crystallization of the mold slag affects both the heat transfer and the lubrication between the mold and the strand in continuous casting of steel. In order for mold slag design to become an engineering science rather than an empirical exercise, a fundamental understanding of the melting and solidification behavior of a slag must be developed. Thus it is necessary to be able to quantify the phenomena that occur under the thermal conditions that are found in the mold of a continuous caster. The double hot thermocouple technique (DHTT) and the Confocal Laser Scanning Microscope used in this study are two novel techniques for investigating melting and solidification phenomena of transparent slags. Results from these techniques are useful in defining the phenomena that occur when the slag film infiltrates between the mold and the shell of the casting. TTT diagrams were obtained for various slags and indicated that the onset of crystallization is a function of cooling rate and slag chemistry. Crystal morphology was found to be dependent upon the experimental temperature and four different morphologies were classified based upon the degree of melt undercooling. Continuous cooling experiments were carried out to develop CCT diagrams and it was found that the amount and appearance of the crystalline fraction greatly depends on the cooling conditions. The DHTT can also be used to mimic the cooling profile encountered by the slag in the mold of a continuous caster. In this differential cooling mode (DCT), it was found that the details of the cooling rate determine the actual response of the slag to a thermal gradient and small changes can lead to significantly different results. Crystal growth rates were measured and found to be in the range between 0.11 mum/s to 11.73 mum/s depending on temperature and slag chemistry. Alumina particles were found to be effective innoculants in oxide melts reducing the incubation time for the onset of crystallization and also extending

  18. Bending and turbulent enhancement phenomena of neutral gas flow containing an atmospheric pressure plasma by applying external electric fields measured by schlieren optical method

    NASA Astrophysics Data System (ADS)

    Yamada, Hiromasa; Yamagishi, Yusuke; Sakakita, Hajime; Tsunoda, Syuichiro; Kasahara, Jiro; Fujiwara, Masanori; Kato, Susumu; Itagaki, Hirotomo; Kim, Jaeho; Kiyama, Satoru; Fujiwara, Yutaka; Ikehara, Yuzuru; Ikehara, Sanae; Nakanishi, Hayao; Shimizu, Nobuyuki

    2016-01-01

    To understand the mechanism of turbulent enhancement phenomena of a neutral gas flow containing plasma ejected from the nozzle of plasma equipment, the schlieren optical method was performed to visualize the neutral gas behavior. It was confirmed that the turbulent starting point became closer to the nozzle exit, as the amplitude of discharge voltage (electric field) increased. To study the effect of electric field on turbulent enhancement, two sets of external electrodes were arranged in parallel, and the gas from the nozzle was allowed to flow between the upper and lower electrodes. It was found that the neutral gas flow was bent, and the bending angle increased as the amplitude of the external electric field increased. The results obtained using a simple model analysis roughly coincide with experimental data. These results indicate that momentum transport from drifted ions induced by the electric field to neutral particles is an important factor that enhances turbulence.

  19. Study of the atmospheric flashes and man-made global phenomena ultraviolet and infrared glow of the night air on the board of satellite "VERNOV"

    NASA Astrophysics Data System (ADS)

    Garipov, Gali; Panasyuk, Mikhael; Svertilov, Sergey; Bogomolov, Vitaliy; Barinova, Vera; Saleev, Kirill

    2016-04-01

    The set of scientific payload for optical observation on-board of "Vernov" satellite, launched at July 8, 2014, had measured transient (millisecond) flashes in the atmosphere in two wavelength bands: ultraviolet (UV,240-380nm) and red-infrared (IR,610-800nm). Global distribution of the flashes, their frequency and time parameters are studied in this work. Transient flashes measured from the satellite frequently were detected in high latitudes in winter time. Flashes in equatorial region were observed in series which were stretched along magnetic meridian and some of them were detected in cloudless regions. At night time when the Earth atmosphere was observed in nadir direction there were registered the optical signals of artificial origin, distributed along the meridian in an extended region of latitude in the Northern and Southern hemispheres of the Earth, modulated by low frequency and at the coincidence of the orbits with the geographic location of the powerful radio stations. Examples of the waveforms of such signals in UV and IR spectral ranges and their global distribution are presented in this presentation. Particular attention is paid to man-made causes of the glow in the ionosphere under the influence of the high power radio wave transmitters of low (LF) and high frequencies (HF). The height of the luminescence source and components of the atmosphere, which can be the sources of this radiation, are discussed.

  20. Thermal Wave Phenomena

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This map from the MGS Horizon Sensor Assembly (HORSE) shows middle atmospheric temperatures near the 1 mbar level of Mars between Ls 170 to 175 (approx. July 14 - 23, 1999). Local Mars times between 1:30 and 4:30 AM are included. Infrared radiation measured by the Mars Horizon Sensor Assembly was used to make the map. That device continuously views the 'limb' of Mars in four directions, to help orient the spacecraft instruments to the nadir: straight down.

    The map shows thermal wave phenomena that are caused by the large topographic variety of Mars' surface, as well the latitudinally symmetric behavior expected at this time of year near the equinox.

  1. Global and frequent appearance of small spatial scale field-aligned currents possibly driven by the lower atmospheric phenomena as observed by the CHAMP satellite in middle and low latitudes

    NASA Astrophysics Data System (ADS)

    Nakanishi, Kunihito; Iyemori, Toshihiko; Taira, Kento; Lühr, Hermann

    2014-12-01

    Using magnetic field data obtained by the Challenging Minisatellite Payload (CHAMP), we show global and frequent appearance of small-amplitude (1 to 5 nT on the dayside) magnetic fluctuations with period around a few tens of seconds along the satellite orbit in middle and low latitudes. They are different from known phenomena, such as the Pc3 pulsations. The following characteristics are presented and discussed in this paper: (1) The magnetic fluctuations are perpendicular to the geomagnetic main field, and the amplitude of the zonal (east-west) component is larger than that of the meridional component in general. (2) As latitude becomes lower around the dip equator, the period tends to become longer. (3) The amplitudes have clear local time dependence, which is highly correlated to the ionospheric conductivities in local time (LT) 06-18. (4) The amplitude of the fluctuations shows magnetic conjugacy to a certain extent. (5) The amplitude shows no dependence on solar wind parameters nor geomagnetic activity. (6) A seasonal dependence is seen clearly. The amplitudes in the northern summer and winter are larger than those in the equinoxes. In the northern summer, the amplitudes above the Eurasian and South American continents and their conjugate areas are larger. In the northern winter, those above the eastern Pacific Ocean are larger. We suggest that the above characteristics, (1) to (6), can be attributed to the small spatial scale field-aligned currents having a lower atmospheric origin through the ionospheric dynamo process.

  2. Wave phenomena in sunspots

    NASA Astrophysics Data System (ADS)

    Löhner-Böttcher, Johannes

    2016-03-01

    Context: The dynamic atmosphere of the Sun exhibits a wealth of magnetohydrodynamic (MHD) waves. In the presence of strong magnetic fields, most spectacular and powerful waves evolve in the sunspot atmosphere. Allover the sunspot area, continuously propagating waves generate strong oscillations in spectral intensity and velocity. The most prominent and fascinating phenomena are the 'umbral flashes' and 'running penumbral waves' as seen in the sunspot chromosphere. Their nature and relation have been under intense discussion in the last decades. Aims: Waves are suggested to propagate upward along the magnetic field lines of sunspots. An observational study is performed to prove or disprove the field-guided nature and coupling of the prevalent umbral and penumbral waves. Comprehensive spectroscopic observations at high resolution shall provide new insights into the wave characteristics and distribution across the sunspot atmosphere. Methods: Two prime sunspot observations were carried out with the Dunn Solar Telescope at the National Solar Observatory in New Mexico and with the Vacuum Tower Telescope at the Teide Observatory on Tenerife. The two-dimensional spectroscopic observations were performed with the interferometric spectrometers IBIS and TESOS. Multiple spectral lines are scanned co-temporally to sample the dynamics at the photospheric and chromospheric layers. The time series (1 – 2.5 h) taken at high spatial and temporal resolution are analyzed according to their evolution in spectral intensities and Doppler velocities. A wavelet analysis was used to obtain the wave power and dominating wave periods. A reconstruction of the magnetic field inclination based on sunspot oscillations was developed. Results and conclusions: Sunspot oscillations occur continuously in spectral intensity and velocity. The obtained wave characteristics of umbral flashes and running penumbral waves strongly support the scenario of slow-mode magnetoacoustic wave propagation along

  3. Coupled Phenomena in Chemistry.

    ERIC Educational Resources Information Center

    Matsubara, Akira; Nomura, Kazuo

    1979-01-01

    Various phenomena in chemistry and biology can be understood through Gibbs energy utilization. Some common phenomena in chemistry are explained including neutralization, hydrolysis, oxidation and reaction, simultaneous dissociation equilibrium of two weak acids, and common ion effect on solubility. (Author/SA)

  4. Ion exchange phenomena

    SciTech Connect

    Bourg, I.C.; Sposito, G.

    2011-05-01

    Ion exchange phenomena involve the population of readily exchangeable ions, the subset of adsorbed solutes that balance the intrinsic surface charge and can be readily replaced by major background electrolyte ions (Sposito, 2008). These phenomena have occupied a central place in soil chemistry research since Way (1850) first showed that potassium uptake by soils resulted in the release of an equal quantity of moles of charge of calcium and magnesium. Ion exchange phenomena are now routinely modeled in studies of soil formation (White et al., 2005), soil reclamation (Kopittke et al., 2006), soil fertilitization (Agbenin and Yakubu, 2006), colloidal dispersion/flocculation (Charlet and Tournassat, 2005), the mechanics of argillaceous media (Gajo and Loret, 2007), aquitard pore water chemistry (Tournassat et al., 2008), and groundwater (Timms and Hendry, 2007; McNab et al., 2009) and contaminant hydrology (Chatterjee et al., 2008; van Oploo et al., 2008; Serrano et al., 2009).

  5. Imaging of snapping phenomena

    PubMed Central

    Guillin, R; Marchand, A J; Roux, A; Niederberger, E; Duvauferrier, R

    2012-01-01

    Snapping phenomena result from the sudden impingement between anatomical and/or heterotopical structures with subsequent abrupt movement and noise. Snaps are variously perceived by patients, from mild discomfort to significant pain requiring surgical management. Identifying the precise cause of snaps may be challenging when no abnormality is encountered on routinely performed static examinations. In this regard, dynamic imaging techniques have been developed over time, with various degrees of success. This review encompasses the main features of each imaging technique and proposes an overview of the main snapping phenomena in the musculoskeletal system. PMID:22744321

  6. Stress pulse phenomena

    SciTech Connect

    McGlaun, M.

    1993-08-01

    This paper is an introductory discussion of stress pulse phenomena in simple solids and fluids. Stress pulse phenomena is a very rich and complex field that has been studied by many scientists and engineers. This paper describes the behavior of stress pulses in idealized materials. Inviscid fluids and simple solids are realistic enough to illustrate the basic behavior of stress pulses. Sections 2 through 8 deal with the behavior of pressure pulses. Pressure is best thought of as the average stress at a point. Section 9 deals with shear stresses which are most important in studying solids.

  7. Quantum phenomena in superconductors

    SciTech Connect

    Clarke, J.

    1987-08-01

    This paper contains remarks by the author on aspects of macroscopic quantum phenomena in superconductors. Some topics discussed are: Superconducting low-inductance undulatory galvanometer (SLUGS), charge imbalance, cylindrical dc superconducting quantum interference device (SQUIDS), Geophysics, noise theory, magnetic resonance with SQUIDS, and macroscopic quantum tunneling. 23 refs., 4 figs. (LSP)

  8. Atmospheric optics in art.

    PubMed

    Gedzelman, S D

    1991-08-20

    A brief historical overview of the atmospheric optical phenomena that appear in works of fine art is presented. It is shown that artists have recorded many features of the color and brightness of the sky and clouds, aerial perspective and visibility effects, and phenomena, including crepuscular rays, rainbows, halos, and coronas. Artistic biases resulting from prevailing styles and societal influences are noted. Attention is drawn to a number of phenomena recorded by artists that have not yet been explained or modeled. PMID:20706420

  9. Electronic phenomena at high pressure

    SciTech Connect

    Drickamer, H.G.

    1981-01-01

    High pressure research is undertaken either to investigate intrinsically high pressure phenomena or in order to get a better understanding of the effect of the chemical environment on properties or processes at one atmosphere. Studies of electronic properties which fall in each area are presented. Many molecules and complexes can assume in the excited state different molecular arrangements and intermolecular forces depending on the medium. Their luminescence emission is then very different in a rigid or a fluid medium. With pressure one can vary the viscosity of the medium by a factor of 10/sup 7/ and thus control the distribution and rate of crossing between the excited state conformations. In rare earth chelates the efficiency of 4f-4f emission of the rare earth is controlled by the feeding from the singlet and triplet levels of the organic ligand. These ligand levels can be strongly shifted by pressure. A study of the effect of pressure on the emission efficiency permits one to understand the effect of ligand chemistry at one atmosphere. At high pressure electronic states can be sufficiently perturbed to provide new ground states. In EDA complexes these new ground states exhibit unusual chemical reactivity and new products.

  10. Membrane Transport Phenomena (MTP)

    NASA Technical Reports Server (NTRS)

    Mason, Larry W.

    1997-01-01

    The third semi-annual period of the MTP project has been involved with performing experiments using the Membrane Transport Apparatus (MTA), development of analysis techniques for the experiment results, analytical modeling of the osmotic transport phenomena, and completion of a DC-9 microgravity flight to test candidate fluid cell geometries. Preparations were also made for the MTP Science Concept Review (SCR), held on 13 June 1997 at Lockheed Martin Astronautics in Denver. These activities are detailed in the report.

  11. Wolf-Rayet phenomena

    NASA Technical Reports Server (NTRS)

    Conti, P. S.

    1982-01-01

    The properties of stars showing Wolf-Rayet phenomena are outlined along with the direction of future work. Emphasis is placed on the characteristics of W-R spectra. Specifically the following topics are covered: the absolute visual magnitudes; the heterogeneity of WN spectra; the existence of transition type spectra and compositions the mass loss rates; and the existence of very luminous and possibly very massive W-R stars. Also, a brief overview of current understanding of the theoretical aspects of stellar evolution and stellar winds and the various scenarios that have been proposed to understand W-R spectra are included.

  12. Phenomena Associated with EIT Waves

    NASA Technical Reports Server (NTRS)

    Thompson, B. J.; Biesecker, D. A.; Gopalswamy, N.; Fisher, Richard R. (Technical Monitor)

    2002-01-01

    We discuss phenomena associated with 'EIT Wave' transients. These phenomena include coronal mass ejections, flares, EUV/SXR dimmings, chromospheric waves, Moreton waves, solar energetic particle events, energetic electron events, and radio signatures. Although the occurrence of many phenomena correlate with the appearance of EIT waves, it is difficult to infer which associations are causal. The presentation will include a discussion of correlation surveys of these phenomena.

  13. Phenomena Associated With EIT Waves

    NASA Technical Reports Server (NTRS)

    Thompson, B. J.; Biesecker, D. A.; Gopalswamy, N.

    2003-01-01

    We discuss phenomena associated with "EIT Wave" transients. These phenomena include coronal mass ejections, flares, EUV/SXR dimmings, chromospheric waves, Moreton waves, solar energetic particle events, energetic electron events, and radio signatures. Although the occurrence of many phenomena correlate with the appearance of EIT waves, it is difficult to mfer which associations are causal. The presentation will include a discussion of correlation surveys of these phenomena.

  14. MULTISCALE PHENOMENA IN MATERIALS

    SciTech Connect

    A. BISHOP

    2000-09-01

    This project developed and supported a technology base in nonequilibrium phenomena underpinning fundamental issues in condensed matter and materials science, and applied this technology to selected problems. In this way the increasingly sophisticated synthesis and characterization available for classes of complex electronic and structural materials provided a testbed for nonlinear science, while nonlinear and nonequilibrium techniques helped advance our understanding of the scientific principles underlying the control of material microstructure, their evolution, fundamental to macroscopic functionalities. The project focused on overlapping areas of emerging thrusts and programs in the Los Alamos materials community for which nonlinear and nonequilibrium approaches will have decisive roles and where productive teamwork among elements of modeling, simulations, synthesis, characterization and applications could be anticipated--particularly multiscale and nonequilibrium phenomena, and complex matter in and between fields of soft, hard and biomimetic materials. Principal topics were: (i) Complex organic and inorganic electronic materials, including hard, soft and biomimetic materials, self-assembly processes and photophysics; (ii) Microstructure and evolution in multiscale and hierarchical materials, including dynamic fracture and friction, dislocation and large-scale deformation, metastability, and inhomogeneity; and (iii) Equilibrium and nonequilibrium phases and phase transformations, emphasizing competing interactions, frustration, landscapes, glassy and stochastic dynamics, and energy focusing.

  15. Monsoon circulation and atmospheric ozone

    NASA Astrophysics Data System (ADS)

    Khrgian, A. Kh.; Nguyen, Van Thang

    1991-01-01

    The effect of the Indonesian-Australian winter monsoon, proceeding from the Asian continent to the south, on the atmospheric ozone is examined. It is shown that large-scale atmospheric circulation phenomena caused by monsoons in the tropical regions of Australia and in south-eastern Asia can cause significant falls in atmospheric ozone concentrations. The common occurrence of such phenomena might explain the higher-than-average incidence of skin cancer in Australia.

  16. Weld pool phenomena

    SciTech Connect

    David, S.A.; Vitek, J.M.; Zacharia, T.; DebRoy, T.

    1994-09-01

    During welding, the composition, structure and properties of the welded structure are affected by the interaction of the heat source with the metal. The interaction affects the fluid flow, heat transfer and mass transfer in the weld pool, and the solidification behavior of the weld metal. In recent years, there has been a growing recognition of the importance of the weld pool transport processes and the solid state transformation reactions in determining the composition, structure and properties of the welded structure. The relation between the weld pool transport processes and the composition and structure is reviewed. Recent applications of various solidification theories to welding are examined to understand the special problems of weld metal solidification. The discussion is focussed on the important problems and issues related to weld pool transport phenomena and solidification. Resolution of these problems would be an important step towards a science based control of composition, structure and properties of the weld metal.

  17. Wave propagation phenomena

    NASA Astrophysics Data System (ADS)

    Groenenboom, P. H. L.

    The phenomenon of wave propagation is encountered frequently in a variety of engineering disciplines. It has been realized that for a growing number of problems the solution can only be obtained by discretization of the boundary. Advantages of the Boundary Element Method (BEM) over domain-type methods are related to the reduction of the number of space dimensions and of the modelling effort. It is demonstrated how the BEM can be applied to wave propagation phenomena by establishing the fundamental relationships. A numerical solution procedure is also suggested. In connection with a discussion of the retarded potential formulation, it is shown how the wave propagation problem can be cast into a Boundary Integral Formulation (BIF). The wave propagation problem in the BIF can be solved by time-successive evaluation of the boundary integrals. The example of pressure wave propagation following a sodium-water reaction in a Liquid Metal cooled Fast Breeder Reactor steam generator is discussed.

  18. PREFACE Integrability and nonlinear phenomena Integrability and nonlinear phenomena

    NASA Astrophysics Data System (ADS)

    Gómez-Ullate, David; Lombardo, Sara; Mañas, Manuel; Mazzocco, Marta; Nijhoff, Frank; Sommacal, Matteo

    2010-10-01

    Back in 1967, Clifford Gardner, John Greene, Martin Kruskal and Robert Miura published a seminal paper in Physical Review Letters which was to become a cornerstone in the theory of integrable systems. In 2006, the authors of this paper received the AMS Steele Prize. In this award the AMS pointed out that `In applications of mathematics, solitons and their descendants (kinks, anti-kinks, instantons, and breathers) have entered and changed such diverse fields as nonlinear optics, plasma physics, and ocean, atmospheric, and planetary sciences. Nonlinearity has undergone a revolution: from a nuisance to be eliminated, to a new tool to be exploited.' From this discovery the modern theory of integrability bloomed, leading scientists to a deep understanding of many nonlinear phenomena which is by no means reachable by perturbation methods or other previous tools from linear theories. Nonlinear phenomena appear everywhere in nature, their description and understanding is therefore of great interest both from the theoretical and applicative point of view. If a nonlinear phenomenon can be represented by an integrable system then we have at our disposal a variety of tools to achieve a better mathematical description of the phenomenon. This special issue is largely dedicated to investigations of nonlinear phenomena which are related to the concept of integrability, either involving integrable systems themselves or because they use techniques from the theory of integrability. The idea of this special issue originated during the 18th edition of the Nonlinear Evolution Equations and Dynamical Systems (NEEDS) workshop, held at Isola Rossa, Sardinia, Italy, 16-23 May 2009 (http://needs-conferences.net/2009/). The issue benefits from the occasion offered by the meeting, in particular by its mini-workshops programme, and contains invited review papers and contributed papers. It is worth pointing out that there was an open call for papers and all contributions were peer reviewed

  19. Atmospheric Photochemistry

    NASA Technical Reports Server (NTRS)

    Massey, Harrie; Potter, A. E.

    1961-01-01

    The upper atmosphere offers a vast photochemical laboratory free from solid surfaces, so all reactions take place in the gaseous phase. At 30 km altitude the pressure has fallen to about one-hundredth of that at ground level, and we shall, rather arbitrarily, regard the upper atmosphere as beginning at that height. By a little less than 100 km the pressure has fallen to 10(exp -3) mm Hg and is decreasing by a power of ten for every 15 km increase in altitude. Essentially we are concerned then with the photochemistry of a nitrogen-oxygen mixture under low-pressure conditions in which photo-ionization, as well as photodissociation, plays an important part. Account must also be taken of the presence of rare constituents, such as water vapour and its decomposition products, including particularly hydroxyl, oxides of carbon, methane and, strangely enough, sodium, lithium and calcium. Many curious and unfamiliar reactions occur in the upper atmosphere. Some of them are luminescent, causing the atmosphere to emit a dim light called the airglow. Others, between gaseous ions and neutral molecules, are almost a complete mystery at this time. Similar interesting phenomena must occur in other planetary atmospheres, and they might be predicted if sufficient chemical information were available.

  20. Arcjet Cathode Phenomena

    NASA Technical Reports Server (NTRS)

    Curran, Francis M.; Haag, Thomas W.; Raquet, John F.

    1989-01-01

    Cathode tips made from a number of different materials were tested in a modular arcjet thruster in order to examine cathode phenomena. Periodic disassembly and examination, along with the data collected during testing, indicated that all of the tungsten-based materials behaved similarly despite the fact that in one of these samples the percentage of thorium oxide was doubled and another was 25 percent rhenium. The mass loss rate from a 2 percent thoriated rhenium cathode was found to be an order of magnitude greater than that observed using 2 percent thoriated tungsten. Detailed analysis of one of these cathode tips showed that the molten crater contained pure tungsten to a depth of about 150 microns. Problems with thermal stress cracking were encountered in the testing of a hafnium carbide tip. Post test analysis showed that the active area of the tip had chemically reacted with the propellant. A 100 hour continuous test was run at about 1 kW. Post test analysis revealed no dendrite formation, such as observed in a 30 kW arcjet lifetest, near the cathode crater. The cathodes from both this test and a previously run 1000 hour cycled test displayed nearly identical arc craters. Data and calculations indicate that the mass losses observed in testing can be explained by evaporation.

  1. Arcjet cathode phenomena

    NASA Technical Reports Server (NTRS)

    Curran, Francis M.; Haag, Thomas W.; Raquet, John F.

    1989-01-01

    Cathode tips made from a number of different materials were tested in a modular arcjet thruster in order to examine cathode phenomena. Periodic disassembly and examination, along with the data collected during testing, indicated that all of the tungsten-based materials behaved similarly despite the fact that in one of these samples the percentage of thorium oxide was doubled and another was 25 percent rhenium. The mass loss rate from a 2 percent thoriated rhenium cathode was found to be an order of magnitude greater than that observed using 2 percent thoriated tungsten. Detailed analysis of one of these cathode tips showed that the molten crater contained pure tungsten to a depth of about 150 microns. Problems with thermal stress cracking were encountered in the testing of a hafnium carbide tip. Post test analysis showed that the active area of the tip had chemically reacted with the propellant. A 100 hour continuous test was run at about 1 kW. Post test analysis revealed no dendrite formation, such as observed in a 30 kW arcjet lifetest, near the cathode crater. The cathodes from both this test and a previously run 1000 hour cycled test displayed nearly identical arc craters. Data and calculations indicate that the mass losses observed in testing can be explained by evaporation.

  2. ON DETECTING TRANSIENT PHENOMENA

    SciTech Connect

    Belanger, G.

    2013-08-10

    Transient phenomena are interesting and potentially highly revealing of details about the processes under observation and study that could otherwise go unnoticed. It is therefore important to maximize the sensitivity of the method used to identify such events. In this article, we present a general procedure based on the use of the likelihood function for identifying transients which is particularly suited for real-time applications because it requires no grouping or pre-processing of the data. The method makes use of all the information that is available in the data throughout the statistical decision-making process, and is suitable for a wide range of applications. Here we consider those most common in astrophysics, which involve searching for transient sources, events or features in images, time series, energy spectra, and power spectra, and demonstrate the use of the method in the case of a weak X-ray flare in a time series and a short-lived quasi-periodic oscillation in a power spectrum. We derive a fit statistic that is ideal for fitting arbitrarily shaped models to a power density distribution, which is of general interest in all applications involving periodogram analysis.

  3. Time-Variable Phenomena in the Jovian System

    NASA Technical Reports Server (NTRS)

    Belton, Michael J. S. (Editor); West, Robert A. (Editor); Rahe, Jurgen (Editor); Pereyda, Margarita

    1989-01-01

    The current state of knowledge of dynamic processes in the Jovian system is assessed and summaries are provided of both theoretical and observational foundations upon which future research might be based. There are three sections: satellite phenomena and rings; magnetospheric phenomena, Io's torus, and aurorae; and atmospheric phenomena. Each chapter discusses time dependent theoretical framework for understanding and interpreting what is observed; others describe the evidence and nature of observed changes or their absence. A few chapters provide historical perspective and attempt to present a comprehensive synthesis of the current state of knowledge.

  4. Relaxation phenomena in disordered systems

    NASA Astrophysics Data System (ADS)

    Sciortino, F.; Tartaglia, P.

    1997-02-01

    In this article we discuss how the assumptions of self-similarity imposed on the distribution of independently relaxing modes, as well as on their amplitude and characteristic times, manifest in the global relaxation phenomena. We also review recent applications of such approach to the description of relaxation phenomena in microemulsions and molecular glasses.

  5. Teaching Optical Phenomena with Tracker

    ERIC Educational Resources Information Center

    Rodrigues, M.; Carvalho, P. Simeão

    2014-01-01

    Since the invention and dissemination of domestic laser pointers, observing optical phenomena is a relatively easy task. Any student can buy a laser and experience at home, in a qualitative way, the reflection, refraction and even diffraction phenomena of light. However, quantitative experiments need instruments of high precision that have a…

  6. Phenomena resulting from hypergolic contact

    NASA Astrophysics Data System (ADS)

    Forness, Jordan M.

    Understanding hypergolic ignition is critical for the safe and successful operation of hypergolic engines. The complex coupling of physical and chemical processes during hypergolic ignition complicates analysis of the event. Presently, hypergolic ignition models cannot simulate liquid contact and mixing or liquid-phase chemical reactions, and rely on experimental results for validation. In some cases, chemical kinetics of hypergolic propellants and fluid dynamics of droplet collisions couple to produce unexpected phenomena. This research investigates contact between droplets and pools of liquid hypergolic propellants under various conditions in order to investigate these liquid-phase reactions and categorize the resulting interaction. During this experiment, 142 drop tests were performed to investigate phenomena associated with hypergolic contact of various propellants. A drop of fuel impacted a semi-ellipsoidal pool of oxidizer at varying impact velocities and impact geometries. The temperature, pressure, ambient atmosphere, and propellant quality were all controlled during the experiment, as these factors have been shown to influence hypergolic ignition delay. Three distinct types of impacts were identified: explosions, bounces, and splashes. The impact type was found to depend on the impact Weber number and impact angle. Splashes occurred above a critical Weber number of 250, regardless of impact angle. Explosions occurred for Weber numbers less than 250, and for impact angles less than seven degrees. If the impact angle was greater than seven degrees then the test resulted in a bounce. Literature related to explosions induced by hypergolic contact was reviewed. Explosions were observed to occur inconsistently, a feature that has never been addressed. Literature related to non-reactive splashing, bouncing, and coalescence was reviewed for insight into the explosion phenomenon. I propose that the dependence of impact angle on the transition between explosion and

  7. Misconceptions of Emergent Semiconductor Phenomena

    NASA Astrophysics Data System (ADS)

    Nelson, Katherine G.

    The semiconductor field of Photovoltaics (PV) has experienced tremendous growth, requiring curricula to consider ways to promote student success. One major barrier to success students may face when learning PV is the development of misconceptions. The purpose of this work was to determine the presence and prevalence of misconceptions students may have for three PV semiconductor phenomena; Diffusion, Drift and Excitation. These phenomena are emergent, a class of phenomena that have certain characteristics. In emergent phenomena, the individual entities in the phenomena interact and aggregate to form a self-organizing pattern that can be observed at a higher level. Learners develop a different type of misconception for these phenomena, an emergent misconception. Participants (N=41) completed a written protocol. The pilot study utilized half of these protocols (n = 20) to determine the presence of both general and emergent misconceptions for the three phenomena. Once the presence of both general and emergent misconceptions was confirmed, all protocols (N=41) were analyzed to determine the presence and prevalence of general and emergent misconceptions, and to note any relationships among these misconceptions (full study). Through written protocol analysis of participants' responses, numerous codes emerged from the data for both general and emergent misconceptions. General and emergent misconceptions were found in 80% and 55% of participants' responses, respectively. General misconceptions indicated limited understandings of chemical bonding, electricity and magnetism, energy, and the nature of science. Participants also described the phenomena using teleological, predictable, and causal traits, indicating participants had misconceptions regarding the emergent aspects of the phenomena. For both general and emergent misconceptions, relationships were observed between similar misconceptions within and across the three phenomena, and differences in misconceptions were

  8. Critical velocity phenomena and the LTP. [Lunar Transient Phenomena

    NASA Technical Reports Server (NTRS)

    Srnka, L. J.

    1977-01-01

    When the relative velocity between magnetized plasma and neutral gas exceeds a critical value, the gas-plasma interaction is dominated by collective phenomena which rapidly excite and ionize the neutrals. The interaction of the solar wind with a large cloud (between 10 to the 24th and 10 to the 28th power neutrals) vented from the moon should be of this type. Line radiation from such an interaction can yield an apparent lunar surface brightness rivaling reflected sunlight levels over small areas, if the kinetic-energy flow density of the gas is sufficiently high. The aberrated solar-wind flow past the moon would enhance the visibility of such interactions near the lunar sunrise terminator, supporting the statistical studies which indicate that the 'Lunar Transient Phenomena' (anomalous optical phenomena on the moon) are significantly correlated with the position of the terminator on the lunar surface.

  9. Teaching optical phenomena with Tracker

    NASA Astrophysics Data System (ADS)

    Rodrigues, M.; Simeão Carvalho, P.

    2014-11-01

    Since the invention and dissemination of domestic laser pointers, observing optical phenomena is a relatively easy task. Any student can buy a laser and experience at home, in a qualitative way, the reflection, refraction and even diffraction phenomena of light. However, quantitative experiments need instruments of high precision that have a relatively complex setup. Fortunately, nowadays it is possible to analyse optical phenomena in a simple and quantitative way using the freeware video analysis software ‘Tracker’. In this paper, we show the advantages of video-based experimental activities for teaching concepts in optics. We intend to show: (a) how easy the study of such phenomena can be, even at home, because only simple materials are needed, and Tracker provides the necessary measuring instruments; and (b) how we can use Tracker to improve students’ understanding of some optical concepts. We give examples using video modelling to study the laws of reflection, Snell’s laws, focal distances in lenses and mirrors, and diffraction phenomena, which we hope will motivate teachers to implement it in their own classes and schools.

  10. Undergraduates' understanding of cardiovascular phenomena.

    PubMed

    Michael, Joel A; Wenderoth, Mary Pat; Modell, Harold I; Cliff, William; Horwitz, Barbara; McHale, Philip; Richardson, Daniel; Silverthorn, Dee; Williams, Stephen; Whitescarver, Shirley

    2002-12-01

    Undergraduates students in 12 courses at 8 different institutions were surveyed to determine the prevalence of 13 different misconceptions (conceptual difficulties) about cardiovascular function. The prevalence of these misconceptions ranged from 20 to 81% and, for each misconception, was consistent across the different student populations. We also obtained explanations for the students' answers either as free responses or with follow-up multiple-choice questions. These results suggest that students have a number of underlying conceptual difficulties about cardiovascular phenomena. One possible source of some misconceptions is the students' inability to apply simple general models to specific cardiovascular phenomena. Some implications of these results for teachers of physiology are discussed. PMID:12031940

  11. Abnormal pressures as hydrodynamic phenomena

    USGS Publications Warehouse

    Neuzil, C.E.

    1995-01-01

    So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

  12. Magnetohydrodynamic (MHD) modelling of solar active phenomena via numerical methods

    NASA Technical Reports Server (NTRS)

    Wu, S. T.

    1988-01-01

    Numerical ideal MHD models for the study of solar active phenomena are summarized. Particular attention is given to the following physical phenomena: (1) local heating of a coronal loop in an isothermal and stratified atmosphere, and (2) the coronal dynamic responses due to magnetic field movement. The results suggest that local heating of a magnetic loop will lead to the enhancement of the density of the neighboring loops through MHD wave compression. It is noted that field lines can be pinched off and may form a self-contained magnetized plasma blob that may move outward into interplanetary space.

  13. Radioactive γ/β tracer to explore dangerous technogenic phenomena

    NASA Astrophysics Data System (ADS)

    Nagorsky, P. M.; Yakovleva, V. S.; Makarov, E. O.; Firstov, P. P.; Kondratyeva, A. G.; Stepanenko, A. A.

    2016-06-01

    A radioactive γ/β tracer to explore dangerous technogenic phenomena has been proposed: the ratio of the measured flux density of β- and γ-radiations in the surface layer of the atmosphere. The time dependence analysis of the ratio of β- and γ-pulse count rate has been carried out. A significant increase of the γ/β ratio was recorded under the cyclone passing through Japan (Fukushima) to Kamchatka. The proposed γ/β tracer can be a very sensitive indicator of nonstationary processes related to hazardous natural and technogenic phenomena.

  14. Visualizing Chemical Phenomena in Microdroplets

    ERIC Educational Resources Information Center

    Lee, Sunghee; Wiener, Joseph

    2011-01-01

    Phenomena that occur in microdroplets are described to the undergraduate chemistry community. Droplets having a diameter in the micrometer range can have unique and interesting properties, which arise because of their small size and, especially, their high surface area-to-volume ratio. Students are generally unfamiliar with the characteristics of…

  15. Statistical phenomena in particle beams

    SciTech Connect

    Bisognano, J.J.

    1984-09-01

    Particle beams are subject to a variety of apparently distinct statistical phenomena such as intrabeam scattering, stochastic cooling, electron cooling, coherent instabilities, and radiofrequency noise diffusion. In fact, both the physics and mathematical description of these mechanisms are quite similar, with the notion of correlation as a powerful unifying principle. In this presentation we will attempt to provide both a physical and a mathematical basis for understanding the wide range of statistical phenomena that have been discussed. In the course of this study the tools of the trade will be introduced, e.g., the Vlasov and Fokker-Planck equations, noise theory, correlation functions, and beam transfer functions. Although a major concern will be to provide equations for analyzing machine design, the primary goal is to introduce a basic set of physical concepts having a very broad range of applicability.

  16. New phenomena searches at CDF

    SciTech Connect

    Soha, Aron; /UC, Davis

    2006-04-01

    The authors report on recent results from the Collider Detector at Fermilab (CDF) experiment, which is accumulating data from proton-antiproton collisions with {radical}s = 1.96 TeV at Run II of the Fermilab Tevatron. The new phenomena being explored include Higgs, Supersymmetry, and large extra dimensions. They also present the latest results of searches for heavy objects, which would indicate physics beyond the Standard Model.

  17. Mathematical Modeling of Diverse Phenomena

    NASA Technical Reports Server (NTRS)

    Howard, J. C.

    1979-01-01

    Tensor calculus is applied to the formulation of mathematical models of diverse phenomena. Aeronautics, fluid dynamics, and cosmology are among the areas of application. The feasibility of combining tensor methods and computer capability to formulate problems is demonstrated. The techniques described are an attempt to simplify the formulation of mathematical models by reducing the modeling process to a series of routine operations, which can be performed either manually or by computer.

  18. Visualization of solidification front phenomena

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.; Smith, Guy A.

    1993-01-01

    Directional solidification experiments have been utilized throughout the Materials Processing in Space Program to provide an experimental platform which minimizes variables in solidification experiments. Because of the wide-spread use of this experimental technique in space-based research, it has become apparent that a better understanding of all the phenomena occurring during solidification can be better understood if direct visualization of the solidification interface were possible.

  19. Cathodic phenomena in aluminum electrowinning

    NASA Astrophysics Data System (ADS)

    Bouteillon, J.; Poignet, J. C.; Rameau, J. J.

    1993-02-01

    Although aluminum is one of the world's highest production-volume primary metals, it is particularly costly to produce for a variety of factors, not the least of which are the expenses associated with electrolytic reduction. Based on the scale of global aluminum processing, even minor improvements in the electrowinning technology can result in significant savings of resources. Thus, from this perspective, the following reviews recent studies of cathodic phenomena in aluminum electrowinning.

  20. Dynamical phenomena: implications for extreme event attribution

    NASA Astrophysics Data System (ADS)

    Mitchell, Dann; Davini, Paolo; Harvey, Ben; Massey, Neil; Haustein, Karsten; Woollings, Tim; Jones, Richard; Otto, Fredi; Guillod, Benoit; Sparrow, Sarah; Wallom, David; Allen, Myles

    2016-04-01

    Atmospheric modes of variability relevant for extreme temperature and precipitation events are evaluated in models currently being used for extreme event attribution. A multi-thousand initial condition ensemble of the global circulation model HadAM3P is compared with both the multi-model ensemble from the Coupled Model Inter-comparison Project, Phase 5 (CMIP-5) and the CMIP-5 atmosphere-only counterparts (AMIP-5). The analysis focuses on mid Northern Latitudes (primarily Europe) during winter, and is compared with ERA-Interim reanalysis. The tri-modal Atlantic Eddy-driven jet distribution is remarkably well captured in HadAM3P, but not so in CMIP-5 or AMIP-5. The well known underestimation of blocking in the Atlantic region is apparent in CMIP-5 and AMIP-5, and to a lesser extent in HadAM3P. Pacific blocking features are well produced in all modeling initiatives. Blocking duration is generally biased towards models reproducing too many short-lived events. Associated storm tracks are too zonal over the Atlantic in the CMIP-5 ensemble, but well simulated in HadAM3P with the exception of being too weak over Western Europe. In all cases, the CMIP-5 and AMIP-5 performances were almost identical, suggesting that the atmospheric modes considered here are not strongly coupled to SSTs, and perhaps other model characteristics such as resolution are more important. It is recommended that only models capable of producing the necessary dynamical phenomena be used for event attribution analyses.

  1. PREFACE Integrability and nonlinear phenomena Integrability and nonlinear phenomena

    NASA Astrophysics Data System (ADS)

    Gómez-Ullate, David; Lombardo, Sara; Mañas, Manuel; Mazzocco, Marta; Nijhoff, Frank; Sommacal, Matteo

    2010-10-01

    Back in 1967, Clifford Gardner, John Greene, Martin Kruskal and Robert Miura published a seminal paper in Physical Review Letters which was to become a cornerstone in the theory of integrable systems. In 2006, the authors of this paper received the AMS Steele Prize. In this award the AMS pointed out that `In applications of mathematics, solitons and their descendants (kinks, anti-kinks, instantons, and breathers) have entered and changed such diverse fields as nonlinear optics, plasma physics, and ocean, atmospheric, and planetary sciences. Nonlinearity has undergone a revolution: from a nuisance to be eliminated, to a new tool to be exploited.' From this discovery the modern theory of integrability bloomed, leading scientists to a deep understanding of many nonlinear phenomena which is by no means reachable by perturbation methods or other previous tools from linear theories. Nonlinear phenomena appear everywhere in nature, their description and understanding is therefore of great interest both from the theoretical and applicative point of view. If a nonlinear phenomenon can be represented by an integrable system then we have at our disposal a variety of tools to achieve a better mathematical description of the phenomenon. This special issue is largely dedicated to investigations of nonlinear phenomena which are related to the concept of integrability, either involving integrable systems themselves or because they use techniques from the theory of integrability. The idea of this special issue originated during the 18th edition of the Nonlinear Evolution Equations and Dynamical Systems (NEEDS) workshop, held at Isola Rossa, Sardinia, Italy, 16-23 May 2009 (http://needs-conferences.net/2009/). The issue benefits from the occasion offered by the meeting, in particular by its mini-workshops programme, and contains invited review papers and contributed papers. It is worth pointing out that there was an open call for papers and all contributions were peer reviewed

  2. Meteorological phenomena in Western classical orchestral music

    NASA Astrophysics Data System (ADS)

    Williams, P. D.; Aplin, K. L.

    2012-12-01

    The creative output of composers, writers, and artists is often influenced by their surroundings. To give a literary example, it has been claimed recently that some of the characters in Oliver Twist and A Christmas Carol were based on real-life people who lived near Charles Dickens in London. Of course, an important part of what we see and hear is not only the people with whom we interact, but also our geophysical surroundings. Of all the geophysical phenomena to influence us, the weather is arguably the most significant, because we are exposed to it directly and daily. The weather was a great source of inspiration for Monet, Constable, and Turner, who are known for their scientifically accurate paintings of the skies. But to what extent does weather inspire composers? The authors of this presentation, who are atmospheric scientists by day but amateur classical musicians by night, have been contemplating this question. We have built a systematic musical database, which has allowed us to catalogue and analyze the frequencies with which weather is depicted in a sample of classical orchestral music. The depictions vary from explicit mimicry using traditional and specialized orchestral instruments, through to subtle suggestions. We have found that composers are generally influenced by their own environment in the type of weather they choose to represent. As befits the national stereotype, British composers seem disproportionately keen to depict the UK's variable weather patterns and stormy coastline. Reference: Aplin KL and Williams PD (2011) Meteorological phenomena in Western classical orchestral music. Weather, 66(11), pp 300-306. doi:10.1002/wea.765

  3. TRANSIENT LUNAR PHENOMENA: REGULARITY AND REALITY

    SciTech Connect

    Crotts, Arlin P. S.

    2009-05-20

    Transient lunar phenomena (TLPs) have been reported for centuries, but their nature is largely unsettled, and even their existence as a coherent phenomenon is controversial. Nonetheless, TLP data show regularities in the observations; a key question is whether this structure is imposed by processes tied to the lunar surface, or by terrestrial atmospheric or human observer effects. I interrogate an extensive catalog of TLPs to gauge how human factors determine the distribution of TLP reports. The sample is grouped according to variables which should produce differing results if determining factors involve humans, and not reflecting phenomena tied to the lunar surface. Features dependent on human factors can then be excluded. Regardless of how the sample is split, the results are similar: {approx}50% of reports originate from near Aristarchus, {approx}16% from Plato, {approx}6% from recent, major impacts (Copernicus, Kepler, Tycho, and Aristarchus), plus several at Grimaldi. Mare Crisium produces a robust signal in some cases (however, Crisium is too large for a 'feature' as defined). TLP count consistency for these features indicates that {approx}80% of these may be real. Some commonly reported sites disappear from the robust averages, including Alphonsus, Ross D, and Gassendi. These reports begin almost exclusively after 1955, when TLPs became widely known and many more (and inexperienced) observers searched for TLPs. In a companion paper, we compare the spatial distribution of robust TLP sites to transient outgassing (seen by Apollo and Lunar Prospector instruments). To a high confidence, robust TLP sites and those of lunar outgassing correlate strongly, further arguing for the reality of TLPs.

  4. Atmospheric transport and diffusion mechanisms in coastal circulation systems

    SciTech Connect

    Kaleel, R.J.; Shearer, D.L.; MacRae, B.L.

    1983-06-01

    This study defines the cyclical aspects of coastal atmospheric behavior that are important to the transport and diffusion (dispersion) of radionuclides. The report is developed around discussions of the meteorological dynamics of the cyclical and (cellular) atmospheric coastal phenomena and the atmospheric transport/diffusion mechanisms along with an assessment of the measurements accompanying both. Further, the efforts directed to modeling both the atmospheric and transport/diffusion processes are summarized and evaluated. Lastly, the review is summarized through a set of conclusions about the current level of understanding of coastal atmospheric phenomena. Recommendations are offered which identify certain aspects of local scale cyclical coastal phenomena that are important to the NRC.

  5. Correlated randomness and switching phenomena

    NASA Astrophysics Data System (ADS)

    Stanley, H. E.; Buldyrev, S. V.; Franzese, G.; Havlin, S.; Mallamace, F.; Kumar, P.; Plerou, V.; Preis, T.

    2010-08-01

    One challenge of biology, medicine, and economics is that the systems treated by these serious scientific disciplines have no perfect metronome in time and no perfect spatial architecture-crystalline or otherwise. Nonetheless, as if by magic, out of nothing but randomness one finds remarkably fine-tuned processes in time and remarkably fine-tuned structures in space. Further, many of these processes and structures have the remarkable feature of “switching” from one behavior to another as if by magic. The past century has, philosophically, been concerned with placing aside the human tendency to see the universe as a fine-tuned machine. Here we will address the challenge of uncovering how, through randomness (albeit, as we shall see, strongly correlated randomness), one can arrive at some of the many spatial and temporal patterns in biology, medicine, and economics and even begin to characterize the switching phenomena that enables a system to pass from one state to another. Inspired by principles developed by A. Nihat Berker and scores of other statistical physicists in recent years, we discuss some applications of correlated randomness to understand switching phenomena in various fields. Specifically, we present evidence from experiments and from computer simulations supporting the hypothesis that water’s anomalies are related to a switching point (which is not unlike the “tipping point” immortalized by Malcolm Gladwell), and that the bubbles in economic phenomena that occur on all scales are not “outliers” (another Gladwell immortalization). Though more speculative, we support the idea of disease as arising from some kind of yet-to-be-understood complex switching phenomenon, by discussing data on selected examples, including heart disease and Alzheimer disease.

  6. Phenomena and Diosignes of Aratous

    NASA Astrophysics Data System (ADS)

    Avgoloupis, S. I.

    2013-01-01

    Aratous (305-240B.C.) was a singular intellectual, writer and poet which engage himself to compose a very interesting astronomical poet, using the "Dactylous sixstage' style, the formal style of the ancient Greek Epic poetry. This astronomic poem of Aratous "Phenomena and Diosignes" became very favorite reading during the Alexandrine, the Romman and the Byzandin eras as well and had received many praises from significant poets and particularly from Hipparchous and from Theonas from Alexandria, an astronomer of 4rth century A.C.(in Greeks)

  7. Global atmospheric changes.

    PubMed Central

    Piver, W T

    1991-01-01

    Increasing concentrations of CO2 and other greenhouse gases in the atmosphere can be directly related to global warming. In terms of human health, because a major cause of increasing atmospheric concentrations of CO2 is the increased combustion of fossil fuels, global warming also may result in increases in air pollutants, acid deposition, and exposure to ultraviolet (UV) radiation. To understand better the impacts of global warming phenomena on human health, this review emphasizes the processes that are responsible for the greenhouse effect, air pollution, acid deposition, and increased exposure to UV radiation. PMID:1820255

  8. Uranium Pyrophoricity Phenomena and Prediction

    SciTech Connect

    DUNCAN, D.R.

    2000-04-20

    We have compiled a topical reference on the phenomena, experiences, experiments, and prediction of uranium pyrophoricity for the Hanford Spent Nuclear Fuel Project (SNFP) with specific applications to SNFP process and situations. The purpose of the compilation is to create a reference to integrate and preserve this knowledge. Decades ago, uranium and zirconium fires were commonplace at Atomic Energy Commission facilities, and good documentation of experiences is surprisingly sparse. Today, these phenomena are important to site remediation and analysis of packaging, transportation, and processing of unirradiated metal scrap and spent nuclear fuel. Our document, bearing the same title as this paper, will soon be available in the Hanford document system [Plys, et al., 2000]. This paper explains general content of our topical reference and provides examples useful throughout the DOE complex. Moreover, the methods described here can be applied to analysis of potentially pyrophoric plutonium, metal, or metal hydride compounds provided that kinetic data are available. A key feature of this paper is a set of straightforward equations and values that are immediately applicable to safety analysis.

  9. Nonstationary Phenomena in the Heliosheath

    NASA Astrophysics Data System (ADS)

    Pogorelov, N. V.; Borovikov, S. N.; Ebert, R. W.; Heerikhuisen, J.; Kim, T. K.; Kryukov, I.; Richardson, J. D.; Suess, S. T.; Zank, G. P.

    2012-12-01

    As Voyagers (V1 and V2) are approaching the heliopause (HP), they keep delivering important information about the solar wind (SW) behavior which sometimes appears to be substantially different at V1 and V2 locations. We argue that the observed differences may be attributed to SW variations. In particular, negative values of the radial velocity component derived from V1 observations may be due to the presence of time-dependent magnetic barriers formed due to the slow/fast wind interactions in the vicinity of solar cycle minima. The inner heliosheath is the venue of wave interaction, MHD instabilities, and turbulence. We further investigate these phenomena in the HP vicinity using a new, based on the Ulysses observations, solar cycle model. We show that some puzzling observational data, such as the difference in the heliocentric distances at which V1 and V2 crossed the termination shock, may be attributed to time-dependent effects. We also use other time-dependent sets of observational boundary conditions, e.g., interplanetary scintillation and OMNI data. Phenomena affecting the stability and shape of the HP are also discussed in the context of our time-dependent simulations. The satisfaction of the 2-3 kHz radio emission criteria beyond the HP is analyzed. Numerical results are validated by their comparison with observational data.

  10. Natural phenomena hazards, Hanford Site, Washington

    SciTech Connect

    Conrads, T.J.

    1998-09-29

    This document presents the natural phenomena hazard loads for use in implementing DOE Order 5480.28, Natural Phenomena Hazards Mitigation, and supports development of double-shell tank systems specifications at the Hanford Site in south-central Washington State. The natural phenomena covered are seismic, flood, wind, volcanic ash, lightning, snow, temperature, solar radiation, suspended sediment, and relative humidity.

  11. Ultraviolet observations of astronomical phenomena

    NASA Technical Reports Server (NTRS)

    Mullan, D. J.

    1986-01-01

    The purpose was to study various aspects of mass loss in stars of different types. The observational part of the research was directed at three Cepheid variables; the archival part of the research was directed at hot stars (for information on corotating interaction regions) and at cool giants (for study of variability in the mass losing part of the atmosphere).

  12. Quantification of statistical phenomena in turbulent dispersions

    NASA Astrophysics Data System (ADS)

    Yates, Matthew; Hann, David; Hewakandamby, Buddhika

    2015-11-01

    Understanding of turbulent dispersions is of great importance for environmental and industrial applications. This includes developing a greater understanding of particle movement in atmospheric flows, and providing data that can be used to validate CFD models aimed at producing more accurate simulations of dispersed turbulent flows, aiding design of many industrial components. Statistical phenomena in turbulent dispersions were investigated using Particle Image Velocimetry. Experiments were carried out in a two dimensional channel over a Reynolds number range of 10000-30000, using water and 500 micron hydrogel particles. Particles were injected at the channel entrance, and dispersion properties were characterised at different distances downstream from the injection point. Probability density functions were compiled for the velocity components of the hydrogels for differing flow conditions. Higher order PDFs were constructed to investigate the behaviour of particle pairs. Dispersed phase data was also used to investigate the mechanics of collisions between hydrogel particles, allowing for calculation of the co-efficient of restitution. PIV algorithms were used to create velocity maps for the continuous phase for varying dispersed phase fractions. Thanks to support of Chevron grant as part of TMF consortium.

  13. Middle Atmosphere Program. Handbook for MAP, Volume 10

    NASA Technical Reports Server (NTRS)

    Taubenheim, J. (Editor)

    1984-01-01

    The contributions of ground based investigations to the study of middle atmospheric phenomena are addressed. General topics include diagnostics of the middle atmosphere from D region properties, winter anomaly, seasonal variations and disturbances, dynamics and theoretical models, ground based tracking of winds and waves, lower thermosphere phenomena, and solar-terrestrial influences.

  14. Earthquake prediction with electromagnetic phenomena

    NASA Astrophysics Data System (ADS)

    Hayakawa, Masashi

    2016-02-01

    Short-term earthquake (EQ) prediction is defined as prospective prediction with the time scale of about one week, which is considered to be one of the most important and urgent topics for the human beings. If this short-term prediction is realized, casualty will be drastically reduced. Unlike the conventional seismic measurement, we proposed the use of electromagnetic phenomena as precursors to EQs in the prediction, and an extensive amount of progress has been achieved in the field of seismo-electromagnetics during the last two decades. This paper deals with the review on this short-term EQ prediction, including the impossibility myth of EQs prediction by seismometers, the reason why we are interested in electromagnetics, the history of seismo-electromagnetics, the ionospheric perturbation as the most promising candidate of EQ prediction, then the future of EQ predictology from two standpoints of a practical science and a pure science, and finally a brief summary.

  15. Entanglement and boundary critical phenomena

    SciTech Connect

    Zhou Huanqiang; Barthel, Thomas; Schollwoeck, Ulrich; Fjaerestad, John Ove

    2006-11-15

    We investigate boundary critical phenomena from a quantum-information perspective. Bipartite entanglement in the ground state of one-dimensional quantum systems is quantified using the Renyi entropy S{sub {alpha}}, which includes the von Neumann entropy ({alpha}{yields}1) and the single-copy entanglement ({alpha}{yields}{infinity}) as special cases. We identify the contribution of the boundaries to the Renyi entropy, and show that there is an entanglement loss along boundary renormalization group (RG) flows. This property, which is intimately related to the Affleck-Ludwig g theorem, is a consequence of majorization relations between the spectra of the reduced density matrix along the boundary RG flows. We also point out that the bulk contribution to the single-copy entanglement is half of that to the von Neumann entropy, whereas the boundary contribution is the same.

  16. Unidentified phenomena - Unusual plasma behavior?

    NASA Astrophysics Data System (ADS)

    Avakian, S. V.; Kovalenok, V. V.

    1992-06-01

    The paper describes observations of a phenomenon belonging to the UFO category and the possible causes of these events. Special attention is given to an event which occurred during the night of September 19-20, 1974, when a huge 'star' was observed over Pertrozavodsk (Russia), consisting of a bright-white luminous center, emitting beams of light, and a less bright light-blue shell. The star gradually formed a cometlike object with a tail consisting of beams of light and started to descend. It is suggested that this event was related to cosmic disturbances caused by an occurrence of unusually strong solar flares. Other examples are presented that relate unusual phenomena observed in space to the occurrence of strong magnetic turbulence events.

  17. Interpolating function and Stokes phenomena

    NASA Astrophysics Data System (ADS)

    Honda, Masazumi; Jatkar, Dileep P.

    2015-11-01

    When we have two expansions of physical quantity around two different points in parameter space, we can usually construct a family of functions, which interpolates the both expansions. In this paper we study analytic structures of such interpolating functions and discuss their physical implications. We propose that the analytic structures of the interpolating functions provide information on analytic property and Stokes phenomena of the physical quantity, which we approximate by the interpolating functions. We explicitly check our proposal for partition functions of zero-dimensional φ4 theory and Sine-Gordon model. In the zero dimensional Sine-Gordon model, we compare our result with a recent result from resurgence analysis. We also comment on construction of interpolating function in Borel plane.

  18. Emergent Phenomena at Oxide Interfaces

    SciTech Connect

    Hwang, H.Y.

    2012-02-16

    Transition metal oxides (TMOs) are an ideal arena for the study of electronic correlations because the s-electrons of the transition metal ions are removed and transferred to oxygen ions, and hence the strongly correlated d-electrons determine their physical properties such as electrical transport, magnetism, optical response, thermal conductivity, and superconductivity. These electron correlations prohibit the double occupancy of metal sites and induce a local entanglement of charge, spin, and orbital degrees of freedom. This gives rise to a variety of phenomena, e.g., Mott insulators, various charge/spin/orbital orderings, metal-insulator transitions, multiferroics, and superconductivity. In recent years, there has been a burst of activity to manipulate these phenomena, as well as create new ones, using oxide heterostructures. Most fundamental to understanding the physical properties of TMOs is the concept of symmetry of the order parameter. As Landau recognized, the essence of phase transitions is the change of the symmetry. For example, ferromagnetic ordering breaks the rotational symmetry in spin space, i.e., the ordered phase has lower symmetry than the Hamiltonian of the system. There are three most important symmetries to be considered here. (i) Spatial inversion (I), defined as r {yields} -r. In the case of an insulator, breaking this symmetry can lead to spontaneous electric polarization, i.e. ferroelectricity, or pyroelectricity once the point group belongs to polar group symmetry. (ii) Time-reversal symmetry (T) defined as t {yields} -t. In quantum mechanics, the time-evolution of the wave-function {Psi} is given by the phase factor e{sup -iEt/{h_bar}} with E being the energy, and hence time-reversal basically corresponds to taking the complex conjugate of the wave-function. Also the spin, which is induced by the 'spinning' of the particle, is reversed by time-reversal. Broken T-symmetry is most naturally associated with magnetism, since the spin

  19. Critical phenomena in magnetic nanowires.

    PubMed

    Kamalakar, M Venkata; Raychaudhuri, A K

    2009-09-01

    In this paper we report the first experimental study of critical phenomena in case of magnetic nanowires of nickel near the ferromagnetic-paramagnetic transition from the electrical transport properties. Nickel nanowire arrays, prepared by potentiostatic electrodeposition of nickel inside pores of nanoporous anodic alumina template were well characterized by X-ray Diffraction, Transmission electron microscopy and Energy dispersive Spectroscopy. Precise electrical resistance measurement of the nanowire arrays of wire diameter 20 nm have been done in the temperature range between 300 K to 700 K. We see a drop in the Curie temperature as observed from the resistivity anomaly. We analyzed the resistance data near the critical region and extracted the critical exponent alpha directly from the resistance. We observed a decrease in the critical part of the resistivity including a decrease in the magnitude of the critical exponent alpha and severe modification in the correction to scaling. PMID:19928208

  20. Wetting phenomena on rough substrates

    NASA Astrophysics Data System (ADS)

    Li, Hao; Kardar, Mehran

    1990-10-01

    We consider wetting phenomena in the vicinity of rough substrates. The quenched random geometry of the substrate is assumed to be a self-affine fractal with a roughness exponent of ζS. Asymptotic critical properties on approaching complete and critical wetting transitions are studied by combining the replica method with scaling and renormalization-group arguments. We find new critical behavior, controlled by a zero-temperature fixed point, when ζS exceeds the thermal roughness exponent of the emerging wetting layer. The possibility of an effective dimensional reduction due to randomness is considered. In two dimensions a number of exact results are obtained by using a many-body transfer-matrix technique.

  1. In-vessel phenomena -- CORA

    SciTech Connect

    Ott, L.J.; van Rij, W.I.

    1991-01-01

    Experiment-specific models have been employed since 1986 by Oak Ridge National Laboratory (ORNL) severe accident analysis programs for the purpose of boiling water reactor experimental planning and optimum interpretation of experimental results. The large integral tests performed to date, which start from an initial undamaged core state, have involved significantly different-from-prototypic boundary and experimental conditions because of either normal facility limitations or specific experimental constraints. These experiments (ACRR: DF-4, NRU: FLHT-6, and CORA) were designed to obtain specific phenomenological information such as the degradation and interaction of prototypic components and the effects on melt progression of control-blade materials and channel boxes. Applications of ORNL models specific to the KfK CORA-16 and CORA-17 experiments are discussed and significant findings from the experimental analyses such as the following are presented: applicability of available Zircaloy oxidation kinetics correlations; influence of cladding strain on Zircaloy oxidation; influence of spacer grids on the structural heatup; and the impact of treating the gaseous coolant as a gray interacting medium. The experiment-specific models supplement and support the systems-level accident analysis codes. They allow the analyst to accurately quantify the observed experimental phenomena and to compensate for the effect of known uncertainties. They provide a basis for the efficient development of new models for phenomena that are currently not modeled (such as material interactions). They can provide validated phenomenological models (from the results of the experiments) as candidates for incorporation in the systems-level whole-core'' codes.

  2. Jovian atmospheres

    SciTech Connect

    Allison, M.; Travis, L.D.

    1986-10-01

    A conference on the atmosphere of Jupiter produced papers in the areas of thermal and ortho-para hydrogen structure, clouds and chemistry, atmospheric structure, global dynamics, synoptic features and processes, atmospheric dynamics, and future spaceflight opportunities. A session on the atmospheres of Uranus and Neptune was included, and the atmosphere of Saturn was discussed in several papers.

  3. Astronomy and Atmospheric Optics

    NASA Astrophysics Data System (ADS)

    Cowley, Les; Gaina, Alex

    2011-12-01

    The authors discusse the insuccess of the observation of the Total Eclipse of the Moon from 10 december 2011 in Romania and relate them with meteoconditions. Only a very short part of the last penumbral phase was observed, while the inital part and the totality was not observed due to very dense clouds. The change in color and brightness during this phase was signaled. Meanwhile, there is an area of science where clouds are of great use and interest. This area is Atmospheric optics, while the science which study clouds is meteorology. Clouds in combination with Solar and Moon light could give rise to a variety of strange, rare and unobvious phenomena in the atmosphere (sky), sometimes confused with Unidentified Flying Objects (UFO). The importance of meteorology for astronomy and atmospheric optics is underlined and an invitation to astronomers to use unfavourable days for athmospheric observations was sent. The web address of the site by Les Cowley, designed for atmospheric optics phenomena is contained in the text of the entry.

  4. Electromechanical phenomena in semiconductor nanostructures

    NASA Astrophysics Data System (ADS)

    Lew Yan Voon, L. C.; Willatzen, M.

    2011-02-01

    Electromechanical phenomena in semiconductors are still poorly studied from a fundamental and an applied science perspective, even though significant strides have been made in the last decade or so. Indeed, most current electromechanical devices are based on ferroelectric oxides. Yet, the importance of the effect in certain semiconductors is being increasingly recognized. For instance, the magnitude of the electric field in an AlN/GaN nanostructure can reach 1-10 MV/cm. In fact, the basic functioning of an (0001) AlGaN/GaN high electron mobility transistor is due to the two-dimensional electron gas formed at the material interface by the polarization fields. The goal of this review is to inform the reader of some of the recent developments in the field for nanostructures and to point out still open questions. Examples of recent work that involves the piezoelectric and pyroelectric effects in semiconductors include: the study of the optoelectronic properties of III-nitrides quantum wells and dots, the current controversy regarding the importance of the nonlinear piezoelectric effect, energy harvesting using ZnO nanowires as a piezoelectric nanogenerator, the use of piezoelectric materials in surface acoustic wave devices, and the appropriateness of various models for analyzing electromechanical effects. Piezoelectric materials such as GaN and ZnO are gaining more and more importance for energy-related applications; examples include high-brightness light-emitting diodes for white lighting, high-electron mobility transistors, and nanogenerators. Indeed, it remains to be demonstrated whether these materials could be the ideal multifunctional materials. The solutions to these and other related problems will not only lead to a better understanding of the basic physics of these materials, but will validate new characterization tools, and advance the development of new and better devices. We will restrict ourselves to nanostructures in the current article even though the

  5. EDITORIAL: Quantum phenomena in Nanotechnology Quantum phenomena in Nanotechnology

    NASA Astrophysics Data System (ADS)

    Loss, Daniel

    2009-10-01

    Twenty years ago the Institute of Physics launched the journal Nanotechnology from its publishing house based in the home town of Paul Dirac, a legendary figure in the development of quantum mechanics at the turn of the last century. At the beginning of the 20th century, the adoption of quantum mechanical descriptions of events transformed the existing deterministic world view. But in many ways it also revolutionised the progress of research itself. For the first time since the 17th century when Francis Bacon established inductive reasoning as the means of advancing science from fact to axiom to law, theory was progressing ahead of experiments instead of providing explanations for observations that had already been made. Dirac's postulation of antimatter through purely theoretical investigation before its observation is the archetypal example of theory leading the way for experiment. The progress of nanotechnology and the development of tools and techniques that enabled the investigation of systems at the nanoscale brought with them many fascinating observations of phenomena that could only be explained through quantum mechanics, first theoretically deduced decades previously. At the nanoscale, quantum confinement effects dominate the electrical and optical properties of systems. They also render new opportunities for manipulating the response of systems. For example, a better understanding of these systems has enabled the rapid development of quantum dots with precisely determined properties, which can be exploited in a range of applications from medical imaging and photovoltaic solar cells to quantum computation, a radically new information technology being currently developed in many labs worldwide. As the first ever academic journal in nanotechnology, {\\it Nanotechnology} has been the forum for papers detailing progress of the science through extremely exciting times. In the early years of the journal, the investigation of electron spin led to the formulation

  6. The atmosphere as a lens

    NASA Technical Reports Server (NTRS)

    Mazurov, G.; Bazarskiy, O.; Zhukov, V.

    1983-01-01

    The advent of manned satellites has made it possible for man to observe Earth from great distances. Many new phenomena have been discovered in the atmosphere. These are evidently caused by reflection, scattering or refraction of light on crystals and drops of water. It is possible to see small objects on the surface of Earth because of these anomalies.

  7. Monitoring of Transient Lunar Phenomena

    NASA Astrophysics Data System (ADS)

    Barker, Timothy; Farber, Ryan; Ahrendts, Gary

    2014-06-01

    Transient Lunar Phenomena (TLP’s) are described as short-lived changes in the brightness of areas on the face of the Moon. TLP research is characterized by the inability to substantiate, reproduce, and verify findings. Our current research includes the analysis of lunar images taken with two Santa Barbara Instrument Group (SBIG) ST8-E CCD cameras mounted on two 0.36m Celestron telescopes. On one telescope, we are using a sodium filter, and on the other an H-alpha filter, imaging approximately one-third of the lunar surface. We are focusing on two regions: Hyginus and Ina. Ina is of particular interest because it shows evidence of recent activity (Schultz, P., Staid, M., Pieters, C. Nature, Volume 444, Issue 7116, pp. 184-186, 2006). A total of over 50,000 images have been obtained over approximately 35 nights and visually analyzed to search for changes. As of March, 2014, no evidence of TLPs has been found. We are currently developing a Matlab program to do image analysis to detect TLPs that might not be apparent by visual inspection alone.

  8. Modeling Defect-Induced Phenomena

    NASA Astrophysics Data System (ADS)

    Kuklja, Maija M.; Rashkeev, Sergey N.

    Elucidation of dissociation mechanisms, energy localization, and transfer phenomena in the course of explosive decomposition of energetic materials (EMs) are central for understanding, controlling, and enhancing the performance of these materials as fuels, propellants, and explosives. Quality of energetic materials is often judged using two main parameters: sensitivity to detonation and its performance. Low sensitivity is desired to make the material relatively stable to external stimuli, i.e., controllable and able of triggering rapid dissociation only when needed and not accidentally. Performance, on the other hand, is to be high to provide larger heat of the explosive reaction. These parameters do not necessarily correlate with each other and depend on many variables such as molecular and crystalline structures, history of samples, the particle size, crystal hardness and orientation, external stimuli, aging, storage conditions, and others. Mechanisms governing performance are fairly well understood whereas mechanisms of sensitivity are poorly known and need to be much more extensively studied. It is widely accepted though that the thermal decomposition reactions of the materials play a significant role in their sensitivity to mechanical stimuli and their explosive properties [1].

  9. Review - Axial compressor stall phenomena

    NASA Technical Reports Server (NTRS)

    Greitzer, E. M.

    1980-01-01

    Stall in compressors can be associated with the initiation of several types of fluid dynamic instabilities. These instabilities and the different phenomena, surge and rotating stall, which result from them, are discussed in this paper. Assessment is made of the various methods of predicting the onset of compressor and/or compression system instability, such as empirical correlations, linearized stability analyses, and numerical unsteady flow calculation procedures. Factors which affect the compressor stall point, in particular inlet flow distortion, are reviewed, and the techniques which are used to predict the loss in stall margin due to these factors are described. The influence of rotor casing treatment (grooves) on increasing compressor flow range is examined. Compressor and compression system behavior subsequent to the onset of stall is surveyed, with particular reference to the problem of engine recovery from a stalled condition. The distinction between surge and rotating stall is emphasized because of the very different consequences on recoverability. The structure of the compressor flow field during rotating stall is examined, and the prediction of compressor performance in rotating stall, including stall/unstall hysteresis, is described.

  10. WESF natural phenomena hazards survey

    SciTech Connect

    Wagenblast, G.R., Westinghouse Hanford

    1996-07-01

    A team of engineers conducted a systematic natural hazards phenomena (NPH) survey for the 225-B Waste Encapsulation and Storage Facility (WESF). The survey is an assessment of the existing design documentation to serve as the structural design basis for WESF, and the Interim Safety Basis (ISB). The lateral force resisting systems for the 225-B building structures, and the anchorages for the WESF safety related systems were evaluated. The original seismic and other design analyses were technically reviewed. Engineering judgment assessments were made of the probability of NPH survival, including seismic, for the 225-B structures and WESF safety systems. The method for the survey is based on the experience of the investigating engineers,and documented earthquake experience (expected response) data.The survey uses knowledge on NPH performance and engineering experience to determine the WESF strengths for NPH resistance, and uncover possible weak links. The survey, in general, concludes that the 225-B structures and WESF safety systems are designed and constructed commensurate with the current Hanford Site design criteria.

  11. Bleed Hole Flow Phenomena Studied

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Boundary-layer bleed is an invaluable tool for controlling the airflow in supersonic aircraft engine inlets. Incoming air is decelerated to subsonic speeds prior to entering the compressor via a series of oblique shocks. The low momentum flow in the boundary layer interacts with these shocks, growing in thickness and, under some conditions, leading to flow separation. To remedy this, bleed holes are strategically located to remove mass from the boundary layer, reducing its thickness and helping to maintain uniform flow to the compressor. The bleed requirements for any inlet design are unique and must be validated by extensive wind tunnel testing to optimize performance and efficiency. To accelerate this process and reduce cost, researchers at the NASA Lewis Research Center initiated an experimental program to study the flow phenomena associated with bleed holes. Knowledge of these flow properties will be incorporated into computational fluid dynamics (CFD) models that will aid engine inlet designers in optimizing bleed configurations before any hardware is fabricated. This ongoing investigation is currently examining two hole geometries, 90 and 20 (both with 5-mm diameters), and various flow features.

  12. Precursor films in wetting phenomena.

    PubMed

    Popescu, M N; Oshanin, G; Dietrich, S; Cazabat, A-M

    2012-06-20

    The spontaneous spreading of non-volatile liquid droplets on solid substrates poses a classic problem in the context of wetting phenomena. It is well known that the spreading of a macroscopic droplet is in many cases accompanied by a thin film of macroscopic lateral extent, the so-called precursor film, which emanates from the three-phase contact line region and spreads ahead of the latter with a much higher speed. Such films have been usually associated with liquid-on-solid systems, but in the last decade similar films have been reported to occur in solid-on-solid systems. While the situations in which the thickness of such films is of mesoscopic size are fairly well understood, an intriguing and yet to be fully understood aspect is the spreading of microscopic, i.e. molecularly thin, films. Here we review the available experimental observations of such films in various liquid-on-solid and solid-on-solid systems, as well as the corresponding theoretical models and studies aimed at understanding their formation and spreading dynamics. Recent developments and perspectives for future research are discussed. PMID:22627067

  13. Intrinsic interfacial phenomena in manganite heterostructures

    NASA Astrophysics Data System (ADS)

    Vaz, C. A. F.; Walker, F. J.; Ahn, C. H.; Ismail-Beigi, S.

    2015-04-01

    We review recent advances in our understanding of interfacial phenomena that emerge when dissimilar materials are brought together at atomically sharp and coherent interfaces. In particular, we focus on phenomena that are intrinsic to the interface and review recent work carried out on perovskite manganites interfaces, a class of complex oxides whose rich electronic properties have proven to be a useful playground for the discovery and prediction of novel phenomena.

  14. Electromagnetic phenomena and hysteresis losses in superconductors

    NASA Astrophysics Data System (ADS)

    Matsushita, T.

    Hysteresis losses in superconductors are caused by irreversible motion of fluxoids. This motion is, in most cases, described by the critical state model. In this article, various electromagnetic phenomena due to flux pinning effects are reviewed and explanations of these phenomena are given using the critical state model. The phenomena which cannot be well described by the present model, such as reversible fluxoid motion and the longitudinal field effect, are also introduced.

  15. Nonepileptic motor phenomena in the neonate

    PubMed Central

    Huntsman, Richard James; Lowry, Noel John; Sankaran, Koravangattu

    2008-01-01

    The newborn infant is prone to clinical motor phenomena that are not epileptic in nature. These include tremors, jitteriness, various forms of myoclonus and brainstem release phenomena. They are frequently misdiagnosed as seizures, resulting in unnecessary investigations and treatment with anticonvulsants, which have potentially harmful side effects. Unfortunately, there is a paucity of literature about many of these phenomena in the newborn, and some of the major textbooks refer to these events as nonepileptic seizures, leading to further confusion for the practitioner. The present paper aims to review these phenomena with special emphasis on differentiating them from epileptic seizures, and offers information on treatment and prognosis wherever possible. PMID:19436521

  16. Observation of Celestial Phenomena in Ancient China

    NASA Astrophysics Data System (ADS)

    Sun, Xiaochun

    Because of the need for calendar-making and portent astrology, the Chinese were diligent and meticulous observers of celestial phenomena. China has maintained the longest continuous historical records of celestial phenomena in the world. Extraordinary or abnormal celestial events were particularly noted because of their astrological significance. The historical records cover various types of celestial phenomena, which include solar and lunar eclipses, sunspots, "guest stars" (novae or supernovae as we understand today), comets and meteors, and all kinds of planetary phenomena. These records provide valuable historical data for astronomical studies today.

  17. Dynamics in Atmospheric Physics

    NASA Astrophysics Data System (ADS)

    Lindzen, Richard A.

    2005-08-01

    Motion is manifest in the atmosphere in an almost infinite variety of ways. In Dynamics in Atmospheric Physics, Dr. Richard Lindzen describes the nature of motion in the atmosphere, develops fluid dynamics relevant to the atmosphere, and explores the role of motion in determining the climate and atmospheric composition. The author presents the material in a lecture note style, and the emphasis throughout is on describing phenomena that are at the frontiers of current research, but due attention is given to the methodology of research and to the historical background of these topics. The author's treatment and choice of topics is didactic. Problems at the end of each chapter will help students assimilate the material. In general the discussions emphasize physical concepts, and throughout Dr. Lindzen makes a concerted effort to avoid the notion that dynamic meteorology is simply the derivation of equations and their subsequent solution. His desire is that interested students will delve further into solution details. The book is intended as a text for first year graduate students in the atmospheric sciences. Although the material in the book is self contained, a familiarity with differential equations is assumed; some background in fluid mechanics is helpful.

  18. Dynamics in Atmospheric Physics

    NASA Astrophysics Data System (ADS)

    Lindzen, Richard A.

    1990-06-01

    Motion is manifest in the atmosphere in an almost infinite variety of ways. In Dynamics in Atmospheric Physics, Dr. Richard Lindzen describes the nature of motion in the atmosphere, develops fluid dynamics relevant to the atmosphere, and explores the role of motion in determining the climate and atmospheric composition. The author presents the material in a lecture note style, and the emphasis throughout is on describing phenomena that are at the frontiers of current research, but due attention is given to the methodology of research and to the historical background of these topics. The author's treatment and choice of topics is didactic. Problems at the end of each chapter will help students assimilate the material. In general the discussions emphasize physical concepts, and throughout Dr. Lindzen makes a concerted effort to avoid the notion that dynamic meteorology is simply the derivation of equations and their subsequent solution. His desire is that interested students will delve further into solution details. The book is intended as a text for first year graduate students in the atmospheric sciences. Although the material in the book is self contained, a familiarity with differential equations is assumed; some background in fluid mechanics is helpful.

  19. New atmospheric sensor analysis study

    NASA Technical Reports Server (NTRS)

    Parker, K. G.

    1989-01-01

    The functional capabilities of the ESAD Research Computing Facility are discussed. The system is used in processing atmospheric measurements which are used in the evaluation of sensor performance, conducting design-concept simulation studies, and also in modeling the physical and dynamical nature of atmospheric processes. The results may then be evaluated to furnish inputs into the final design specifications for new space sensors intended for future Spacelab, Space Station, and free-flying missions. In addition, data gathered from these missions may subsequently be analyzed to provide better understanding of requirements for numerical modeling of atmospheric phenomena.

  20. Planetary atmospheres. [reviewing recent research

    NASA Technical Reports Server (NTRS)

    Leovy, Conway

    1987-01-01

    Observations and theoretical models of planetary atmospheres published during the period 1983-1986 are reviewed, including Vega and Voyager data and results from ground-based remote sensing. Consideration is given to water-vapor and sulfur-compound distributions, electrical phenomena, and dynamics in the Venus atmosphere; dust storms, water cycles, and water and ice erosion on Mars; the compositions, temperature profiles, and dynamics of the Jovian and Saturnian atmospheres; chemical processes and zonal winds on Titan; and the radiation budgets and chemical compositions of the outer planets.

  1. Atmospheric propagation effects relevant to optical communications

    NASA Technical Reports Server (NTRS)

    Shaik, K. S.

    1988-01-01

    A number of atmospheric phenomena affect the propagation of light. The effects of clear air turbulence are reviewed as well as atmospheric turbidity on optical communications. Among the phenomena considered are astronomical and random refraction, scintillation, beam broadening, spatial coherence, angle of arrival, aperture averaging, absorption and scattering, and the effect of opaque clouds. An extensive reference list is also provided for further study. Useful information on the atmospheric propagation of light in relation to optical deep space communications to an earth based receiving station is available, however, further data must be generated before such a link can be designed with committed performance.

  2. Atmospheric Propagation Effects Relevant to Optical Communications

    NASA Technical Reports Server (NTRS)

    Shaik, K. S.

    1988-01-01

    A number of atmospheric phenomena affect the propagation of light. This article reviews the effects of clear-air turbulence as well as atmospheric turbidity on optical communications. Among the phenomena considered are astronomical and random refraction, scintillation, beam broadening, spatial coherence, angle of arrival, aperture averaging, absorption and scattering, and the effect of opaque clouds. An extensive reference list is also provided for further study, Useful information on the atmospheric propagation of light in resolution to optical deep-space communications to an earth-based receiving station is available, however, further data must be generated before such a link can be designed with committed performance.

  3. Fluctuation theory of critical phenomena in fluids

    NASA Astrophysics Data System (ADS)

    Martynov, G. A.

    2016-07-01

    It is assumed that critical phenomena are generated by density wave fluctuations carrying a certain kinetic energy. It is noted that all coupling equations for critical indices are obtained within the context of this hypothesis. Critical indices are evaluated for 15 liquids more accurately than when using the current theory of critical phenomena.

  4. Unsteady flow phenomena in industrial centrifugal compressor stage

    NASA Technical Reports Server (NTRS)

    Bonciani, L.; Terrinoni, L.; Tesei, A.

    1982-01-01

    The results of an experimental investigation on a typical centrifugal compressor stage running on an atmospheric pressure test rig are shown. Unsteady flow was invariably observed at low flow well before surge. In order to determine the influence of the statoric components, the same impeller was repeatedly tested with the same vaneless diffuser, but varying return channel geometry. Experimental results show the strong effect exerted by the return channel, both on onset and on the behavior of unsteady flow. Observed phenomena have been found to confirm well the observed dynamic behavior of full load tested machines when gas density is high enough to cause appreciable mechanical vibrations. Therefore, testing of single stages at atmospheric pressure may provide a fairly accurate prediction of this kind of aerodynamic excitation.

  5. Dusty Plasmas - Kinetic Studies of Strong Coupling Phenomena

    NASA Astrophysics Data System (ADS)

    Morfill, Gregor

    2011-10-01

    ``Dusty plasmas'' can be found almost everywhere - in the interstellar medium, in star and planet formation, in the solar system in the Earth's atmosphere and in the laboratory. In astrophysical plasmas the dust component accounts for only about 1% of the mass, nevertheless this component has a profound influence on the thermodynamics, the chemistry and the dynamics. Important physical processes are charging, sputtering, cooling, light absorption and radiation pressure, connecting electromagnetic forces to gravity. Surface chemistry is another important aspect. In the laboratory there is great interest in industrial processes (e.g. etching, vapor deposition) and at the fundamental physics level - the main topic here - the study of strong coupling phenomena. Here the dust (or microparticles) are the dominant component of the multi-species plasma. The particles can be observed in real time and pace, individually resolved at all relevant length and time scales. This provides an unprecedented means for studying self-organisation processes in many particle systems including the onset of cooperative phenomena. Due to the comparatively large mass of the microparticles (10-12 to 10-9 g) precision experiments are performed on the ISS. The following topics will be discussed: Phase transitions, phase separation, electrorheology, flow phenomena including the onset of turbulence at the kinetic level.

  6. Moon-based Earth Observation for Large Scale Geoscience Phenomena

    NASA Astrophysics Data System (ADS)

    Guo, Huadong; Liu, Guang; Ding, Yixing

    2016-07-01

    The capability of Earth observation for large-global-scale natural phenomena needs to be improved and new observing platform are expected. We have studied the concept of Moon as an Earth observation in these years. Comparing with manmade satellite platform, Moon-based Earth observation can obtain multi-spherical, full-band, active and passive information,which is of following advantages: large observation range, variable view angle, long-term continuous observation, extra-long life cycle, with the characteristics of longevity ,consistency, integrity, stability and uniqueness. Moon-based Earth observation is suitable for monitoring the large scale geoscience phenomena including large scale atmosphere change, large scale ocean change,large scale land surface dynamic change,solid earth dynamic change,etc. For the purpose of establishing a Moon-based Earth observation platform, we already have a plan to study the five aspects as follows: mechanism and models of moon-based observing earth sciences macroscopic phenomena; sensors' parameters optimization and methods of moon-based Earth observation; site selection and environment of moon-based Earth observation; Moon-based Earth observation platform; and Moon-based Earth observation fundamental scientific framework.

  7. Complex (dusty) plasmas-kinetic studies of strong coupling phenomena

    SciTech Connect

    Morfill, Gregor E.; Ivlev, Alexei V.; Thomas, Hubertus M.

    2012-05-15

    'Dusty plasmas' can be found almost everywhere-in the interstellar medium, in star and planet formation, in the solar system in the Earth's atmosphere, and in the laboratory. In astrophysical plasmas, the dust component accounts for only about 1% of the mass, nevertheless this component has a profound influence on the thermodynamics, the chemistry, and the dynamics. Important physical processes are charging, sputtering, cooling, light absorption, and radiation pressure, connecting electromagnetic forces to gravity. Surface chemistry is another important aspect. In the laboratory, there is great interest in industrial processes (e.g., etching, vapor deposition) and-at the fundamental level-in the physics of strong coupling phenomena. Here, the dust (or microparticles) are the dominant component of the multi-species plasma. The particles can be observed in real time and space, individually resolved at all relevant length and time scales. This provides an unprecedented means for studying self-organisation processes in many-particle systems, including the onset of cooperative phenomena. Due to the comparatively large mass of the microparticles (10{sup -12}to10{sup -9}g), precision experiments are performed on the ISS. The following topics will be discussed: Phase transitions, phase separation, electrorheology, flow phenomena including the onset of turbulence at the kinetic level.

  8. Synchronization Phenomena and Epoch Filter of Electroencephalogram

    NASA Astrophysics Data System (ADS)

    Matani, Ayumu

    Nonlinear electrophysiological synchronization phenomena in the brain, such as event-related (de)synchronization, long distance synchronization, and phase-reset, have received much attention in neuroscience over the last decade. These phenomena contain more electrical than physiological keywords and actually require electrical techniques to capture with electroencephalography (EEG). For instance, epoch filters, which have just recently been proposed, allow us to investigate such phenomena. Moreover, epoch filters are still developing and would hopefully generate a new paradigm in neuroscience from an electrical engineering viewpoint. Consequently, electrical engineers could be interested in EEG once again or from now on.

  9. Understanding Atmospheric Catastrophes

    NASA Technical Reports Server (NTRS)

    Chao, Winston C.

    2009-01-01

    The atmosphere, as in other parts of nature, is full of phenomena that involve rapid transitions from one (quasi-) equilibrium state to another--- i.e. catastrophes. These (quasi-) equilibria are the multiple solutions of the same dynamical system. Unlocking the mystery behind a catastrophe reveals not only the physical mechanism responsible for the transition, but also how the (quasi-) equilibria before and after the transition are maintained. Each catastrophe is different, but they do have some common traits. Understanding these common traits is the first step in studying these catastrophes. In this seminar, three examples chosen based on the speaker's research interest--tropical cyclogenesis, stratospheric sudden warming, and monsoon onset--are given to illustrate how atmospheric catastrophes can be studied.

  10. Perspective: Emergent magnetic phenomena at interfaces

    SciTech Connect

    Suzuki, Yuri

    2015-06-01

    The discovery of emergent magnetic phenomena is of fundamental and technological interest. This perspective highlights recent promising examples of emergent ferromagnetism at complex oxide interfaces in the context of spin based electronics.

  11. Analysis of nuclear reactor instability phenomena

    SciTech Connect

    Lahey, R.T. Jr.

    1993-01-01

    The phenomena known as density-wave instability often occurs in phase change systems, such as boiling water nuclear reactors (BWRS). Our current understanding of density-wave oscillations is in fairly good shape for linear phenomena (eg, the onset of instabilities) but is not very advanced for non-linear phenomena [Lahey and Podowski, 1989]. In particular, limit cycle and chaotic instability modes are not well understood in boiling systems such as current and advanced generation BWRs (eg, SBWR). In particular, the SBWR relies on natural circulation and is thus inherently prone to problems with density-wave instabilities. The purpose of this research is to develop a quantitative understanding of nonlinear nuclear-coupled density-wave instability phenomena in BWRS. This research builds on the work of Achard et al [1985] and Clausse et al [1991] who showed, respectively, that Hopf bifurcations and chaotic oscillations may occur in boiling systems.

  12. Canister storage building natural phenomena design loads

    SciTech Connect

    Tallman, A.M.

    1996-02-01

    This document presents natural phenomena hazard (NPH) loads for use in the design and construction of the Canister Storage Building (CSB), which will be located in the 200 East Area of the Hanford Site.

  13. Nanoflares, Spicules, and Other Small-Scale Dynamic Phenomena on the Sun

    NASA Technical Reports Server (NTRS)

    Klimchuk, James

    2010-01-01

    There is abundant evidence of highly dynamic phenomena occurring on very small scales in the solar atmosphere. For example, the observed pr operties of many coronal loops can only be explained if the loops are bundles of unresolved strands that are heated impulsively by nanoflares. Type II spicules recently discovered by Hinode are an example of small-scale impulsive events occurring in the chromosphere. The exist ence of these and other small-scale phenomena is not surprising given the highly structured nature of the magnetic field that is revealed by photospheric observations. Dynamic phenomena also occur on much lar ger scales, including coronal jets, flares, and CMEs. It is tempting to suggest that these different phenomena are all closely related and represent a continuous distribution of sizes and energies. However, this is a dangerous over simplification in my opinion. While it is tru e that the phenomena all involve "magnetic reconnection" (the changin g of field line connectivity) in some form, how this occurs depends s trongly on the magnetic geometry. A nanoflare resulting from the interaction of tangled magnetic strands within a confined coronal loop is much different from a major flare occurring at the current sheet form ed when a CME rips open an active region. I will review the evidence for ubiquitous small-scale dynamic phenomena on the Sun and discuss wh y different phenomena are not all fundamentally the same.

  14. Convective storms in planetary atmospheres

    NASA Astrophysics Data System (ADS)

    Hueso, R.; Sánchez-Lavega, A.

    2013-05-01

    The atmospheres of the planets in the Solar System have different physical properties that in some cases can be considered as extreme when compared with our own planet's more familiar atmosphere. From the tenuous and cold atmosphere of Mars to the dense and warm atmosphere of Venus in the case of the terrestrial planets, to the gigantic atmospheres of the outer planets, or the nitrogen and methane atmosphere of Saturn's moon Titan, we can find a large variety of physical environments. The comparative study of these atmospheres provides a better understanding of the physics of a geophysical fluid. In many of these worlds convective storms of different intensity appear. They are analogous to terrestrial atmospheres fed by the release of latent heat when one of the gases in the atmosphere condenses and they are therefore called moist convective storms. In many of these planets they can produce severe meteorological phenomena and by studying them in a comparative way we can aspire to get a further insight in the dynamics of these atmospheres even beyond the scope of moist convection. A classical example is the structure of the complex systems of winds in the giant planets Jupiter and Saturn. These winds are zonal and alternate in latitude but their deep structure is not accessible to direct observation. However the behaviour of large--scale convective storms vertically extending over the "weather layer" allows to study the buried roots of these winds. Another interesting atmosphere with a rather different structure of convection is Titan, a world where methane is close to its triple point in the atmosphere and can condense in bright clouds with large precipitation fluxes that may model part of the orography of the surface making Titan a world with a methane cycle similar to the hydrological cycle of Earth's atmosphere.

  15. Solar Atmosphere Models

    NASA Astrophysics Data System (ADS)

    Rutten, R. J.

    2002-12-01

    This contribution honoring Kees de Jager's 80th birthday is a review of "one-dimensional" solar atmosphere modeling that followed on the initial "Utrecht Reference Photosphere" of Heintze, Hubenet & de Jager (1964). My starting point is the Bilderberg conference, convened by de Jager in 1967 at the time when NLTE radiative transfer theory became mature. The resulting Bilderberg model was quickly superseded by the HSRA and later by the VAL-FAL sequence of increasingly sophisticated NLTE continuum-fitting models from Harvard. They became the "standard models" of solar atmosphere physics, but Holweger's relatively simple LTE line-fitting model still persists as a favorite of solar abundance determiners. After a brief model inventory I discuss subsequent work on the major modeling issues (coherency, NLTE, dynamics) listed as to-do items by de Jager in 1968. The present conclusion is that one-dimensional modeling recovers Schwarzschild's (1906) finding that the lower solar atmosphere is grosso modo in radiative equilibrium. This is a boon for applications regarding the solar atmosphere as one-dimensional stellar example - but the real sun, including all the intricate phenomena that now constitute the mainstay of solar physics, is vastly more interesting.

  16. A Review of Low Frequency Electromagnetic Wave Phenomena Related to Tropospheric-Ionospheric Coupling Mechanisms

    NASA Technical Reports Server (NTRS)

    Simoes, Fernando; Pfaff, Robert; Berthelier, Jean-Jacques; Klenzing, Jeffrey

    2012-01-01

    Investigation of coupling mechanisms between the troposphere and the ionosphere requires a multidisciplinary approach involving several branches of atmospheric sciences, from meteorology, atmospheric chemistry, and fulminology to aeronomy, plasma physics, and space weather. In this work, we review low frequency electromagnetic wave propagation in the Earth-ionosphere cavity from a troposphere-ionosphere coupling perspective. We discuss electromagnetic wave generation, propagation, and resonance phenomena, considering atmospheric, ionospheric and magnetospheric sources, from lightning and transient luminous events at low altitude to Alfven waves and particle precipitation related to solar and magnetospheric processes. We review in situ ionospheric processes as well as surface and space weather phenomena that drive troposphere-ionosphere dynamics. Effects of aerosols, water vapor distribution, thermodynamic parameters, and cloud charge separation and electrification processes on atmospheric electricity and electromagnetic waves are reviewed. We also briefly revisit ionospheric irregularities such as spread-F and explosive spread-F, sporadic-E, traveling ionospheric disturbances, Trimpi effect, and hiss and plasma turbulence. Regarding the role of the lower boundary of the cavity, we review transient surface phenomena, including seismic activity, earthquakes, volcanic processes and dust electrification. The role of surface and atmospheric gravity waves in ionospheric dynamics is also briefly addressed. We summarize analytical and numerical tools and techniques to model low frequency electromagnetic wave propagation and solving inverse problems and summarize in a final section a few challenging subjects that are important for a better understanding of tropospheric-ionospheric coupling mechanisms.

  17. Atmospheric neutrons

    NASA Technical Reports Server (NTRS)

    Korff, S. A.; Mendell, R. B.; Merker, M.; Light, E. S.; Verschell, H. J.; Sandie, W. S.

    1979-01-01

    Contributions to fast neutron measurements in the atmosphere are outlined. The results of a calculation to determine the production, distribution and final disappearance of atmospheric neutrons over the entire spectrum are presented. An attempt is made to answer questions that relate to processes such as neutron escape from the atmosphere and C-14 production. In addition, since variations of secondary neutrons can be related to variations in the primary radiation, comment on the modulation of both radiation components is made.

  18. NASA/MSFC FY-81 Atmospheric Processes Research Review

    NASA Technical Reports Server (NTRS)

    Turner, R. E. (Compiler)

    1981-01-01

    Progress in ongoing research programs and future plans for satellite investigations into global weather, upper atmospheric phenomena, and severe storms and local weather are summarized. Principle investigators and publications since June 1980 are listed.

  19. Anomalous Light Phenomena vs. Bioelectric Brain Activity

    NASA Astrophysics Data System (ADS)

    Teodorani, M.; Nobili, G.

    We present a research proposal concerning the instrumented investigation of anomalous light phenomena that are apparently correlated with particular mind states, such as prayer, meditation or psi. Previous research by these authors demonstrate that such light phenomena can be monitored and measured quite efficiently in areas of the world where they are reported in a recurrent way. Instruments such as optical equipment for photography and spectroscopy, VLF spectrometers, magnetometers, radar and IR viewers were deployed and used massively in several areas of the world. Results allowed us to develop physical models concerning the structural and time-variable behaviour of light phenomena, and their kinematics. Recent insights and witnesses have suggested to us that a sort of "synchronous connection" seems to exist between plasma-like phenomena and particular mind states of experiencers who seem to trigger a light manifestation which is very similar to the one previously investigated. The main goal of these authors is now aimed at the search for a concrete "entanglement-like effect" between the experiencer's mind and the light phenomena, in such a way that both aspects are intended to be monitored and measured simultaneously using appropriate instrumentation. The goal of this research project is twofold: a) to verify quantitatively the existence of one very particular kind of mind-matter interaction and to study in real time its physical and biophysical manifestations; b) to repeat the same kind of experiment using the same test-subject in different locations and under various conditions of geomagnetic activity.

  20. Investigating the students' understanding of surface phenomena

    NASA Astrophysics Data System (ADS)

    Hamed, Kastro Mohamad

    1999-11-01

    This study investigated students' understanding of surface phenomena. The main purpose for conducting this research endeavor was to understand how students think about a complex topic about which they have little direct or formal instruction. The motivation for focusing on surface phenomena stemmed from an interest in integrating research and education. Despite the importance of surfaces and interfaces in research laboratories, in technological applications, and in everyday experiences, no previous systematic effort was done on pedagogy related to surface phenomena. The design of this research project was qualitative, exploratory, based on a Piagetian semi-structured clinical piloted interview, focused on obtaining a longitudinal view of the intended sample. The sampling was purposeful and the sample consisted of forty-four undergraduate students at Kansas State University. The student participants were enrolled in physics classes that spanned a wide academic spectrum. The data were analyzed qualitatively. The main themes that emerged from the analysis were: (a) students used analogies when confronted with novel situations, (b) students mixed descriptions and explanations, (c) students used the same explanation for several phenomena, (d) students manifested difficulties transferring the meaning of vocabulary across discipline boundaries, (e) in addition to the introductory chemistry classes, students used everyday experiences and job-related experiences as sources of knowledge, and (f) students' inquisitiveness and eagerness to investigate and discuss novel phenomena seemed to peak about the time students were enrolled in second year physics classes.

  1. Pluto's atmosphere

    SciTech Connect

    Elliot, J.L.; Dunham, E.W.; Bosh, A.S.; Slivan, S.M.; Young, L.A.

    1989-01-01

    Airborne CCD photometer observations of Pluto's June 9, 1988 stellar occultation have yielded an occultation lightcurve, probing two regions on the sunrise limb 2000 km apart, which reveals an upper atmosphere overlying an extinction layer with an abrupt upper boundary. The extinction layer may surround the entire planet. Attention is given to a model atmosphere whose occultation lightcurve closely duplicates observations; fits of the model to the immersion and emersion lightcurves exhibit no significant derived atmosphere-structure differences. Assuming a pure methane atmosphere, surface pressures of the order of 3 microbars are consistent with the occultation data. 43 references.

  2. Infrared experiments for spaceborne planetary atmospheres research. Full report

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The role of infrared sensing in atmospheric science is discussed and existing infrared measurement techniques are reviewed. Proposed techniques for measuring planetary atmospheres are criticized and recommended instrument developments for spaceborne investigations are summarized for the following phenomena: global and local radiative budget; radiative flux profiles; winds; temperature; pressure; transient and marginal atmospheres; planetary rotation and global atmospheric activity; abundances of stable constituents; vertical, lateral, and temporal distribution of abundances; composition of clouds and aerosols; radiative properties of clouds and aerosols; cloud microstructure; cloud macrostructure; and non-LTE phenomena.

  3. The making of extraordinary psychological phenomena.

    PubMed

    Lamont, Peter

    2012-01-01

    This article considers the extraordinary phenomena that have been central to unorthodox areas of psychological knowledge. It shows how even the agreed facts relating to mesmerism, spiritualism, psychical research, and parapsychology have been framed as evidence both for and against the reality of the phenomena. It argues that these disputes can be seen as a means through which beliefs have been formulated and maintained in the face of potentially challenging evidence. It also shows how these disputes appealed to different forms of expertise, and that both sides appealed to belief in various ways as part of the ongoing dispute about both the facts and expertise. Finally, it shows how, when a formal Psychology of paranormal belief emerged in the twentieth century, it took two different forms, each reflecting one side of the ongoing dispute about the reality of the phenomena. PMID:25363382

  4. Theories of dynamical phenomena in sunspots

    NASA Technical Reports Server (NTRS)

    Thomas, J. H.

    1981-01-01

    Attempts that have been made to understand and explain observed dynamical phenomena in sunspots within the framework of magnetohydrodynamic theory are surveyed. The qualitative aspects of the theory and physical arguments are emphasized, with mathematical details generally avoided. The dynamical phenomena in sunspots are divided into two categories: aperiodic (quasi-steady) and oscillatory. For each phenomenon discussed, the salient observational features that any theory should explain are summarized. The two contending theoretical models that can account for the fine structure of the Evershed motion, namely the convective roll model and the siphon flow model, are described. With regard to oscillatory phenomena, attention is given to overstability and oscillatory convection, umbral oscillations and flashes. penumbral waves, five-minute oscillations in sunspots, and the wave cooling of sunspots.

  5. Fundamental investigation of duct/ESP phenomena

    SciTech Connect

    Brown, C.A. ); Durham, M.D. ); Sowa, W.A. . Combustion Lab.); Himes, R.M. ); Mahaffey, W.A. )

    1991-10-21

    Radian Corporation was contracted to investigate duct injection and ESP phenomena in a 1.7 MW pilot plant constructed for this test program. This study was an attempt to resolve problems found in previous studies and answer remaining questions for the technology using an approach which concentrates on the fundamental mechanisms of the process. The goal of the study was to obtain a better understanding of the basic physical and chemical phenomena that control: (1) the desulfurization of flue gas by calcium-based reagent, and (2) the coupling of an existing ESP particulate collection device to the duct injection process. Process economics are being studied by others. (VC)

  6. Incorporating interfacial phenomena in solidification models

    NASA Technical Reports Server (NTRS)

    Beckermann, Christoph; Wang, Chao Yang

    1994-01-01

    A general methodology is available for the incorporation of microscopic interfacial phenomena in macroscopic solidification models that include diffusion and convection. The method is derived from a formal averaging procedure and a multiphase approach, and relies on the presence of interfacial integrals in the macroscopic transport equations. In a wider engineering context, these techniques are not new, but their application in the analysis and modeling of solidification processes has largely been overlooked. This article describes the techniques and demonstrates their utility in two examples in which microscopic interfacial phenomena are of great importance.

  7. Modeling of fundamental phenomena in welds

    SciTech Connect

    Zacharia, T.; Vitek, J.M.; Goldak, J.A.; DebRoy, T.A.; Rappaz, M.; Bhadeshia, H.K.D.H.

    1993-12-31

    Recent advances in the mathematical modeling of fundamental phenomena in welds are summarized. State-of-the-art mathematical models, advances in computational techniques, emerging high-performance computers, and experimental validation techniques have provided significant insight into the fundamental factors that control the development of the weldment. The current status and scientific issues in the areas of heat and fluid flow in welds, heat source metal interaction, solidification microstructure, and phase transformations are assessed. Future research areas of major importance for understanding the fundamental phenomena in weld behavior are identified.

  8. Comments on the measurements of multiple muon phenomena

    NASA Technical Reports Server (NTRS)

    Sato, T.; Takahashi, T.; Higashi, S.

    1985-01-01

    The extensive air showers in the energy around 10 to the 15th power eV include those initiated by astrophysical primary gamma-rays. The observations need a precise measurement on the directions of primary particles. It is one of the methods to measure the directions of high-energy muons in air showers. The accuracy in measuring the direction, by calculating the cosmic-ray phenomena in the atmosphere at very high energy was investgated. The results calculated by Monte Carlo method suggest that one may determine the direction of primary cosmic-rays within errors of 10/3 rad in observing muons of above 100 GeV at sea level.

  9. Thermodynamics and Transport Phenomena in High Temperature Steam Electrolysis Cells

    SciTech Connect

    James E. O'Brien

    2012-03-01

    Hydrogen can be produced from water splitting with relatively high efficiency using high temperature electrolysis. This technology makes use of solid-oxide cells, running in the electrolysis mode to produce hydrogen from steam, while consuming electricity and high temperature process heat. The overall thermal-to-hydrogen efficiency for high temperature electrolysis can be as high as 50%, which is about double the overall efficiency of conventional low-temperature electrolysis. Current large-scale hydrogen production is based almost exclusively on steam reforming of methane, a method that consumes a precious fossil fuel while emitting carbon dioxide to the atmosphere. An overview of high temperature electrolysis technology will be presented, including basic thermodynamics, experimental methods, heat and mass transfer phenomena, and computational fluid dynamics modeling.

  10. Multispectral observations complementary to the study of high-energy solar phenomena

    NASA Technical Reports Server (NTRS)

    Walker, Arthur B. C., Jr.

    1988-01-01

    Multispectral observations of phenomena associated with nonthermal events on the sun and characterized by the transient acceleration of electrons and ions to energies ranging from several keV to tens of GeV are discussed. It is shown that observations of the thermal and quasi-thermal phenomena preceeding, coinciding with, and following the impulsive acceleration and heating event itself can be used to study the evolution of magnetic structures in the solar convection zone and atmosphere. Observational techniques are discussed in detail.

  11. Atmospheric chemistry

    SciTech Connect

    Sloane, C.S. ); Tesche, T.W. )

    1991-01-01

    This book covers the predictive strength of atmospheric models. The book covers all of the major important atmospheric areas, including large scale models for ozone depletion and global warming, regional scale models for urban smog (ozone and visibility impairment) and acid rain, as well as accompanying models of cloud processes and biofeedbacks.

  12. The Atmosphere.

    ERIC Educational Resources Information Center

    Ingersoll, Andrew P.

    1983-01-01

    The composition and dynamics of the earth's atmosphere are discussed, considering the atmosphere's role in distributing the energy of solar radiation received by the earth. Models of this activity which help to explain climates of the past and predict those of the future are also considered. (JN)

  13. Satellite Atmosphere and Io Torus Observations

    NASA Technical Reports Server (NTRS)

    Schneider, Nicholas M.

    2000-01-01

    Io is the most volcanically active body in the solar system, and it is embedded deep within the strongest magnetosphere of any planet. This combination of circumstances leads to a host of scientifically compelling phenomena, including (1) an atmosphere out of proportion with such a small object, (2) a correspondingly large atmospheric escape rate, (3) a ring of dense plasma locked in a feedback loop with the atmosphere, and (4) a host of Io-induced emissions from radio bursts to UV auroral spots on Jupiter. This proposal seeks to continue our investigation into the physics connecting these phenomena, with emphasis on Io's atmosphere and plasma torus. The physical processes are clearly of interest for Io, and also other places in the solar system where they are important but not readily observable.

  14. Atmospheric Ionization Measurements

    NASA Astrophysics Data System (ADS)

    Slack, Thomas; Mayes, Riley

    2015-04-01

    The measurement of atmospheric ionization is a largely unexplored science that potentially holds the key to better understanding many different geophysical phenomena through this new and valuable source of data. Through the LaACES program, which is funded by NASA through the Louisiana Space Consortium, students at Loyola University New Orleans have pursued the goal of measuring high altitude ionization for nearly three years, and were the first to successfully collect ionization data at altitudes over 30,000 feet using a scientific weather balloon flown from the NASA Columbia Scientific Ballooning Facility in Palestine, TX. In order to measure atmospheric ionization, the science team uses a lightweight and highly customized sensor known as a Gerdien condenser. Among other branches of science the data is already being used for, such as the study of aerosol pollution levels in the atmosphere, the data may also be useful in meteorology and seismology. Ionization data might provide another variable with which to predict weather or seismic activity more accurately and further in advance. Thomas Slack and Riley Mayes have served as project managers for the experiment, and have extensive knowledge of the experiment from the ground up. LaSPACE Louisiana Space Consortium.

  15. Intervention in Biological Phenomena via Feedback Linearization.

    PubMed

    Fnaiech, Mohamed Amine; Nounou, Hazem; Nounou, Mohamed; Datta, Aniruddha

    2012-01-01

    The problems of modeling and intervention of biological phenomena have captured the interest of many researchers in the past few decades. The aim of the therapeutic intervention strategies is to move an undesirable state of a diseased network towards a more desirable one. Such an objective can be achieved by the application of drugs to act on some genes/metabolites that experience the undesirable behavior. For the purpose of design and analysis of intervention strategies, mathematical models that can capture the complex dynamics of the biological systems are needed. S-systems, which offer a good compromise between accuracy and mathematical flexibility, are a promising framework for modeling the dynamical behavior of biological phenomena. Due to the complex nonlinear dynamics of the biological phenomena represented by S-systems, nonlinear intervention schemes are needed to cope with the complexity of the nonlinear S-system models. Here, we present an intervention technique based on feedback linearization for biological phenomena modeled by S-systems. This technique is based on perfect knowledge of the S-system model. The proposed intervention technique is applied to the glycolytic-glycogenolytic pathway, and simulation results presented demonstrate the effectiveness of the proposed technique. PMID:23209459

  16. Geophysical phenomena classification by artificial neural networks

    NASA Technical Reports Server (NTRS)

    Gough, M. P.; Bruckner, J. R.

    1995-01-01

    Space science information systems involve accessing vast data bases. There is a need for an automatic process by which properties of the whole data set can be assimilated and presented to the user. Where data are in the form of spectrograms, phenomena can be detected by pattern recognition techniques. Presented are the first results obtained by applying unsupervised Artificial Neural Networks (ANN's) to the classification of magnetospheric wave spectra. The networks used here were a simple unsupervised Hamming network run on a PC and a more sophisticated CALM network run on a Sparc workstation. The ANN's were compared in their geophysical data recognition performance. CALM networks offer such qualities as fast learning, superiority in generalizing, the ability to continuously adapt to changes in the pattern set, and the possibility to modularize the network to allow the inter-relation between phenomena and data sets. This work is the first step toward an information system interface being developed at Sussex, the Whole Information System Expert (WISE). Phenomena in the data are automatically identified and provided to the user in the form of a data occurrence morphology, the Whole Information System Data Occurrence Morphology (WISDOM), along with relationships to other parameters and phenomena.

  17. Geophysical phenomena classification by artificial neural networks

    SciTech Connect

    Gough, M.P.; Bruckner, J.R.

    1995-01-01

    Space science information systems involve accessing vast data bases. There is a need for an automatic process by which properties of the whole data set can be assimilated and presented to the user. Where data are in the form of spectrograms, phenomena can be detected by pattern recognition techniques. Presented are the first results obtained by applying unsupervised Artificial Neural Networks (ANN`s) to the classification of magnetospheric wave spectra. The networks used here were a simple unsupervised Hamming network run on a PC and a more sophisticated CALM network run on a Sparc workstation. The ANN`s were compared in their geophysical data recognition performance. CALM networks offer such qualities as fast learning, superiority in generalizing, the ability to continuously adapt to changes in the pattern set, and the possibility to modularize the network to allow the inter-relation between phenomena and data sets. This work is the first step toward an information system interface being developed at Sussex, the Whole Information System Expert (WISE). Phenomena in the data are automatically identified and provided to the user in the form of a data occurrence morphology, the Whole Information System Data Occurrence Morphology (WISDOM), along with relationships to other parameters and phenomena.

  18. Solar Phenomena Associated with "EIT Waves"

    NASA Technical Reports Server (NTRS)

    Biesecker, D. A.; Myers, D. C.; Thompson, B. J.; Hammer, D. M.; Vourlidas, A.

    2002-01-01

    In an effort to understand what an 'EIT wave' is and what its causes are, we have looked for correlations between the initiation of EIT waves and the occurrence of other solar phenomena. An EIT wave is a coronal disturbance, typically appearing as a diffuse brightening propagating across the Sun. A catalog of EIT waves, covering the period from 1997 March through 1998 June, was used in this study. For each EIT wave, the catalog gives the heliographic location and a rating for each wave, where the rating is determined by the reliability of the observations. Since EIT waves are transient, coronal phenomena, we have looked for correlations with other transient, coronal phenomena: X-ray flares, coronal mass ejections (CMEs), and metric type II radio bursts. An unambiguous correlation between EIT waves and CMEs has been found. The correlation of EIT waves with flares is significantly weaker, and EIT waves frequently are not accompanied by radio bursts. To search for trends in the data, proxies for each of these transient phenomena are examined. We also use the accumulated data to show the robustness of the catalog and to reveal biases that must be accounted for in this study.

  19. Wave Phenomena in an Acoustic Resonant Chamber

    ERIC Educational Resources Information Center

    Smith, Mary E.; And Others

    1974-01-01

    Discusses the design and operation of a high Q acoustical resonant chamber which can be used to demonstrate wave phenomena such as three-dimensional normal modes, Q values, densities of states, changes in the speed of sound, Fourier decomposition, damped harmonic oscillations, sound-absorbing properties, and perturbation and scattering problems.…

  20. Spin Circuit Representation for Spin Pumping Phenomena

    NASA Astrophysics Data System (ADS)

    Roy, Kuntal; Datta, Supriyo

    2015-03-01

    There has been enormous progress in the field of spintronics and nanomagnetics in recent years with the discovery of many new materials and phenomena and it remains a formidable challenge to integrate these phenomena into functional devices and evaluate their potential. To facilitate this process a modular approach has been proposed whereby different phenomena are represented by spin circuit components. Unlike ordinary circuit components, these spin circuit components are characterized by 4-component voltages and currents (one for charge and three for spin). In this talk we will (1) present a spin circuit representation for spin pumping phenomena, (2) combine it with a spin circuit representation for the spin Hall effect to show that it reproduces established results obtained earlier by other means, and finally (3) use it to propose a possible method for enhancing the spin pumping efficiency by an order of magnitude through the addition of a spin sink layer. This work was supported by FAME, one of six centers of STARnet, a Semiconductor Research Corporation program sponsored by MARCO and DARPA.

  1. Phylogeny of Aging and Related Phenoptotic Phenomena.

    PubMed

    Libertini, G

    2015-12-01

    The interpretation of aging as adaptive, i.e. as a phenomenon genetically determined and modulated, and with an evolutionary advantage, implies that aging, as any physiologic mechanism, must have phylogenetic connections with similar phenomena. This review tries to find the phylogenetic connections between vertebrate aging and some related phenomena in other species, especially within those phenomena defined as phenoptotic, i.e. involving the death of one or more individuals for the benefit of other individuals. In particular, the aim of the work is to highlight and analyze similarities and connections, in the mechanisms and in the evolutionary causes, between: (i) proapoptosis in prokaryotes and apoptosis in unicellular eukaryotes; (ii) apoptosis in unicellular and multicellular eukaryotes; (iii) aging in yeast and in vertebrates; and (iv) the critical importance of the DNA subtelomeric segment in unicellular and multicellular eukaryotes. In short, there is strong evidence that vertebrate aging has clear similarities and connections with phenomena present in organisms with simpler organization. These phylogenetic connections are a necessary element for the sustainability of the thesis of aging explained as an adaptive phenomenon, and, on the contrary, are incompatible with the opposite view of aging as being due to the accumulation of random damages of various kinds. PMID:26638678

  2. Simple Phenomena, Slow Motion, Surprising Physics

    ERIC Educational Resources Information Center

    Koupil, Jan; Vicha, Vladimir

    2011-01-01

    This article describes a few simple experiments that are worthwhile for slow motion recording and analysis either because of interesting phenomena that can be seen only when slowed down significantly or because of the ability to do precise time measurements. The experiments described in this article are quite commonly done in Czech schools. All…

  3. MIXING PHENOMENA IN INDUSTRIAL FUME AFTERBURNER SYSTEMS

    EPA Science Inventory

    The report reviews the physical-mixing phenomena involved in the reactions that occur in afterburners or fume incinerators. It considers mixing in after-burners from three points of view. It first covers typical designs of afterburner components that are involved in the mixing ph...

  4. A 'Phenomena Laboratory' for Physics Students.

    ERIC Educational Resources Information Center

    Houlden, M. A.; And Others

    1983-01-01

    Describes a laboratory designed to give students practical experiences with experimental phenomena discussed in lectures, focusing on laboratory organization and typical experiment. In addition to a list of experiments, three exercises are discussed: fluorescence/laser, ferromagnetic domains, and thermal population (which uses PET computer…

  5. Temporal Phenomena in the Korean Conjunctive Constructions

    ERIC Educational Resources Information Center

    Kim, Dongmin

    2015-01-01

    The goal of this study is to characterize the temporal phenomena in the Korean conjunctive constructions. These constructions consist of three components: a verbal stem, a clause medial temporal suffix, and a clause terminal suffix. This study focuses on both the temporality of the terminal connective suffixes and the grammatical meanings of the…

  6. Crystal Melting and Wall Crossing Phenomena

    NASA Astrophysics Data System (ADS)

    Yamazaki, Masahito

    This paper summarizes recent developments in the theory of Bogomol'nyi-Prasad-Sommerfield (BPS) state counting and the wall crossing phenomena, emphasizing in particular the role of the statistical mechanical model of crystal melting. This paper is divided into two parts, which are closely related to each other. In the first part, we discuss the statistical mechanical model of crystal melting counting BPS states. Each of the BPS states contributing to the BPS index is in one-to-one correspondence with a configuration of a molten crystal, and the statistical partition function of the melting crystal gives the BPS partition function. We also show that smooth geometry of the Calabi-Yau manifold emerges in the thermodynamic limit of the crystal. This suggests a remarkable interpretation that an atom in the crystal is a discretization of the classical geometry, giving an important clue as such to the geometry at the Planck scale. In the second part, we discuss the wall crossing phenomena. Wall crossing phenomena states that the BPS index depends on the value of the moduli of the Calabi-Yau manifold, and jumps along real codimension one subspaces in the moduli space. We show that by using type IIA/M-theory duality, we can provide a simple and an intuitive derivation of the wall crossing phenomena, furthermore clarifying the connection with the topological string theory. This derivation is consistent with another derivation from the wall crossing formula, motivated by multicentered BPS extremal black holes. We also explain the representation of the wall crossing phenomena in terms of crystal melting, and the generalization of the counting problem and the wall crossing to the open BPS invariants.

  7. Crystal Melting and Wall Crossing Phenomena

    NASA Astrophysics Data System (ADS)

    Yamazaki, Masahito

    2010-02-01

    This paper summarizes recent developments in the theory of Bogomol'nyi-Prasad-Sommerfield (BPS) state counting and the wall crossing phenomena, emphasizing in particular the role of the statistical mechanical model of crystal melting. This paper is divided into two parts, which are closely related to each other. In the first part, we discuss the statistical mechanical model of crystal melting counting BPS states. Each of the BPS state contributing to the BPS index is in one-to-one correspondence with a configuration of a molten crystal, and the statistical partition function of the melting crystal gives the BPS partition function. We also show that smooth geometry of the Calabi-Yau manifold emerges in the thermodynamic limit of the crystal. This suggests a remarkable interpretation that an atom in the crystal is a discretization of the classical geometry, giving an important clue as to the geometry at the Planck scale.In the second part we discuss the wall crossing phenomena. Wall crossing phenomena states that the BPS index depends on the value of the moduli of the Calabi-Yau manifold, and jumps along real codimension one subspaces in the moduli space. We show that by using type IIA/M-theory duality, we can provide a simple and an intuitive derivation of the wall crossing phenomena, furthermore clarifying the connection with the topological string theory. This derivation is consistent with another derivation from the wall crossing formula, motivated by multi-centered BPS extremal black holes. We also explain the representation of the wall crossing phenomena in terms of crystal melting, and the generalization of the counting problem and the wall crossing to the open BPS invariants.

  8. Atmospheric tritium

    SciTech Connect

    Oestlund, H.G.; Mason, A.S.

    1980-01-01

    Research progress for the year 1979 to 1980 are reported. Concentrations of tritiated water vapor, tritium gas and tritiated hydrocarbons in the atmosphere at selected sampling points are presented. (ACR)

  9. Atmospheric pollution

    SciTech Connect

    Pickett, E.E.

    1987-01-01

    Atmospheric pollution (AP), its causes, and measures to prevent or reduce it are examined in reviews and reports presented at a workshop held in Damascus, Syria in August 1985. Topics discussed include AP and planning studies, emission sources, pollutant formation and transformation, AP effects on man and vegetation, AP control, atmospheric dispersion mechanisms and modeling, sampling and analysis techniques, air-quality monitoring, and applications. Diagrams, graphs, and tables of numerical data are provided.

  10. The atmospheres of M dwarfs: Observations

    NASA Technical Reports Server (NTRS)

    Rodono, Marcello

    1987-01-01

    After presenting global properties of M dwarfs, the principal diagnostic of activity phenomena occurring in their atmosphere from the geometrical, energetic, and temporal points of view is stressed. Observations of sunspots, plages, flares, and activity cycles are presented. The major sources of activity are discussed with particular emphasis on the generation, intensification, and measurements of stellar magnetic fields.

  11. Processing and display of atmospheric phenomen data

    NASA Astrophysics Data System (ADS)

    Tatom, F. B.; Garst, R. A.; Purser, L. R.

    1984-10-01

    A series of technical efforts dealing with various atmospheric phenomena is described. Refinements to the Potential in an Electrostatic Cloud (PEC) model are discussed. The development of an Apple III graphics program, the NSSL Lightning Data Program and a description of data reduction procedures are examined. Several utility programs are also discussed.

  12. Processing and display of atmospheric phenomenaa data

    NASA Technical Reports Server (NTRS)

    Tatom, F. B.; Garst, R. A.; Purser, L. R.

    1984-01-01

    A series of technical efforts dealing with various atmospheric phenomena is described. Refinements to the Potential in an Electrostatic Cloud (PEC) model are discussed. The development of an Apple III graphics program, the NSSL Lightning Data Program and a description of data reduction procedures are examined. Several utility programs are also discussed.

  13. Auroral Phenomena: Associated with auroras in complex ways are an extraordinary number of other physical phenomena.

    PubMed

    O'brien, B J

    1965-04-23

    The array of auroral phenomena involves all the basic types of physical phenomena: heat, light, sound, electricity and magnetism, atomic physics, and plasma physics. The uncontrollability, the unreproducibility, and the sheer enormity of the phenomena will keep experimentalists and theorists busy but unsatisfied for many years to come. The greatest challenge in this field of research is an adequate experimentally verifiable theory of the local energization of auroral particle fluxes. Once that is achieved, there is every likelihood that the multitude of correlations between auroral phenomena can be understood and appreciated. Until that time, however, such correlations are to be regarded like icebergs-the parts that can be seen are only a small fraction of the whole phenomenon, and it is the large unseen parts that can be dangerous to theorists and experimentalists alike. PMID:17842831

  14. Coherence Phenomena in Coupled Optical Resonators

    NASA Technical Reports Server (NTRS)

    Smith, D. D.; Chang, H.

    2004-01-01

    We predict a variety of photonic coherence phenomena in passive and active coupled ring resonators. Specifically, the effective dispersive and absorptive steady-state response of coupled resonators is derived, and used to determine the conditions for coupled-resonator-induced transparency and absorption, lasing without gain, and cooperative cavity emission. These effects rely on coherent photon trapping, in direct analogy with coherent population trapping phenomena in atomic systems. We also demonstrate that the coupled-mode equations are formally identical to the two-level atom Schrodinger equation in the rotating-wave approximation, and use this result for the analysis of coupled-resonator photon dynamics. Notably, because these effects are predicted directly from coupled-mode theory, they are not unique to atoms, but rather are fundamental to systems of coherently coupled resonators.

  15. Study of non-equilibrium transport phenomena

    NASA Technical Reports Server (NTRS)

    Sharma, Surendra P.

    1987-01-01

    Nonequilibrium phenomena due to real gas effects are very important features of low density hypersonic flows. The shock shape and emitted nonequilibrium radiation are identified as the bulk flow behavior parameters which are very sensitive to the nonequilibrium phenomena. These parameters can be measured in shock tubes, shock tunnels, and ballistic ranges and used to test the accuracy of computational fluid dynamic (CFD) codes. Since the CDF codes, by necessity, are based on multi-temperature models, it is also desirable to measure various temperatures, most importantly, the vibrational temperature. The CFD codes would require high temperature rate constants, which are not available at present. Experiments conducted at the NASA Electric Arc-driven Shock Tube (EAST) facility reveal that radiation from steel contaminants overwhelm the radiation from the test gas. For the measurement of radiation and the chemical parameters, further investigation and then appropriate modifications of the EAST facility are required.

  16. Optimizing Laboratory Experiments for Dynamic Astrophysical Phenomena

    SciTech Connect

    Ryutov, D; Remington, B

    2005-09-13

    To make a laboratory experiment an efficient tool for the studying the dynamical astrophysical phenomena, it is desirable to perform them in such a way as to observe the scaling invariance with respect to the astrophysical system under study. Several examples are presented of such scalings in the area of magnetohydrodynamic phenomena, where a number of scaled experiments have been performed. A difficult issue of the effect of fine-scale dissipative structures on the global scale dissipation-free flow is discussed. The second part of the paper is concerned with much less developed area of the scalings relevant to the interaction of an ultra-intense laser pulse with a pre-formed plasma. The use of the symmetry arguments in such experiments is also considered.

  17. Transport Phenomena During Equiaxed Solidification of Alloys

    NASA Technical Reports Server (NTRS)

    Beckermann, C.; deGroh, H. C., III

    1997-01-01

    Recent progress in modeling of transport phenomena during dendritic alloy solidification is reviewed. Starting from the basic theorems of volume averaging, a general multiphase modeling framework is outlined. This framework allows for the incorporation of a variety of microscale phenomena in the macroscopic transport equations. For the case of diffusion dominated solidification, a simplified set of model equations is examined in detail and validated through comparisons with numerous experimental data for both columnar and equiaxed dendritic growth. This provides a critical assessment of the various model assumptions. Models that include melt flow and solid phase transport are also discussed, although their validation is still at an early stage. Several numerical results are presented that illustrate some of the profound effects of convective transport on the final compositional and structural characteristics of a solidified part. Important issues that deserve continuing attention are identified.

  18. Kinetically controlled phenomena in dynamic combinatorial libraries.

    PubMed

    Ji, Qing; Lirag, Rio Carlo; Miljanić, Ognjen Š

    2014-03-21

    Dynamic combinatorial libraries (DCLs) are collections of structurally related compounds that can interconvert through reversible chemical reaction(s). Such reversibility endows DCLs with adaptability to external stimuli, as rapid interconversion allows quick expression of those DCL components which best respond to the disturbing stimulus. This Tutorial Review focuses on the kinetically controlled phenomena that occur within DCLs. Specifically, it will describe dynamic chiral resolution of DCLs, their self-sorting under the influence of irreversible chemical and physical stimuli, and the autocatalytic behaviours within DCLs which can result in self-replicating systems. A brief discussion of precipitation-induced phenomena will follow and the review will conclude with the presentation of covalent organic frameworks (COFs)-porous materials whose synthesis critically depends on the fine tuning of the crystal growth and error correction rates within large DCLs. PMID:24445841

  19. A review of impulsive phase phenomena

    NASA Technical Reports Server (NTRS)

    Dejager, C.

    1986-01-01

    A brief review is given of impulsive phase phenomena in support of the models used to compute the energies of the different components of the flares under study. The observational characteristics of the impulsive phase are discussed as well as the evidence for multi-thermal or non-thermal phenomena. The significance of time delays between hard X-rays and microwaves is discussed in terms of electron beams and Alfven waves, two-step acceleration, and secondary bursts at large distances from the primary source. Observations indicating the occurrence of chromospheric evaporation, coronal explosions, and thermal conduction fronts are reviewed briefly, followed by the gamma ray and neutron results. Finally, a preferred flare scenario and energy source are presented involving the interactions in a complex of magnetic loops with the consequent reconnection and electron acceleration.

  20. Coherent topological phenomena in protein folding.

    PubMed

    Bohr, H; Brunak, S; Bohr, J

    1997-01-01

    A theory is presented for coherent topological phenomena in protein dynamics with implications for protein folding and stability. We discuss the relationship to the writhing number used in knot diagrams of DNA. The winding state defines a long-range order along the backbone of a protein with long-range excitations, 'wring' modes, that play an important role in protein denaturation and stability. Energy can be pumped into these excitations, either thermally or by an external force. PMID:9218961

  1. Particle Modelling of Fluid Phenomena in Three -

    NASA Astrophysics Data System (ADS)

    Mahmoudi, Mohsen

    A new, numerical approach is developed to simulate fluid phenomena by means of molecular type behavior. First, consider the large number of molecules to be approximated by a smaller number of aggregates called particles. Then, let the particles interact with each other according to a classical molecular type force vec F whose magnitude F is given (Hirchfelder, Curtiss and Bird (1954)) by: F = rm -{Gover r^{p}} + {Hover r^{q}}, in which G, H, p, q, are positive constants and r is the distance between two particles. The acceleration of each particle is related to the force by the Newtonian dynamical equations vec F = m vec a. Displacement, velocity, and acceleration of each particle are then approximated by the "Leap Frog" formulas. The CRAY X-MP/24 is used to solve numerically the resulting large system of nonlinear, ordinary differential equations. We then study fluid phenomena in the following order. Part 1. Generation of particle fluids in a cylindrical region. Part 2. Verification of basic fluid properties. Part 3. Simulation of surface motion. In this part, we simulate three phenomena, which can be observed physically, by dropping a small object into a container filled with liquid. First, there is a backdrop. Then, a wave will be generated and going outward from the point of entry of the object into the container. Last, a reaction which can be recorded only with a high speed camera (Trefethen (1972)) is that very small drops of the container fluid may actually pinch off from the backdrop. Part 4. Simulation of surface tension. This phenomena can be observed by performing the following experiment. A small needle placed gently upon a water surface will not be sunk but will be supported by the molecular forces in the liquid surface. The molecules in the surface are depressed slightly in the process.

  2. Natural phenomena hazards site characterization criteria

    SciTech Connect

    Not Available

    1994-03-01

    The criteria and recommendations in this standard shall apply to site characterization for the purpose of mitigating Natural Phenomena Hazards (wind, floods, landslide, earthquake, volcano, etc.) in all DOE facilities covered by DOE Order 5480.28. Criteria for site characterization not related to NPH are not included unless necessary for clarification. General and detailed site characterization requirements are provided in areas of meteorology, hydrology, geology, seismology, and geotechnical studies.

  3. Coronal Mass Ejections (CMEs) and Associated Phenomena

    NASA Astrophysics Data System (ADS)

    Manoharan, P. K.

    2008-10-01

    The Sun is the most powerful radio waves emitting object in the sky. The first documented recognition of the reception of radio waves from the Sun was made in 1942 by Hey.15 Since then solar radio observations, from ground-based and space-based instruments, have played a major role in understanding the physics of the Sun and fundamental physical processes of the solar radio emitting phenomena...

  4. Nonlinear phenomena in plasma physics and hydrodynamics

    NASA Astrophysics Data System (ADS)

    Sagdeev, R. Z.

    Advances in the theory of nonlinear phenomena are discussed in individual chapters contributed by Soviet physicists. Topics examined include vortices in plasma and hydrodynamics, oscillations and bifurcations in reversible systems, regular and chaotic dynamics of particles in a magnetic field, and renormalization-group theory and Kolmogorov-Arnold-Moser theory. Consideration is given to nonlinear problems of the turbulent dynamo, strong turbulence and topological solitons, self-oscillations in chemical systems, and autowaves in biologically active media.

  5. Tunable caustic phenomena in electron wavefields.

    PubMed

    Tavabi, Amir Hossein; Migunov, Vadim; Dwyer, Christian; Dunin-Borkowski, Rafal E; Pozzi, Giulio

    2015-10-01

    Novel caustic phenomena, which contain fold, butterfly and elliptic umbilic catastrophes, are observed in defocused images of two approximately collinear oppositely biased metallic tips in a transmission electron microscope. The observed patterns depend sensitively on defocus, on the applied voltage between the tips and on their separation and lateral offset. Their main features are interpreted on the basis of a projected electrostatic potential model for the electron-optical phase shift. PMID:26069930

  6. Seismoelectric Phenomena in Fluid-Saturated Sediments

    SciTech Connect

    Block, G I; Harris, J G

    2005-04-22

    Seismoelectric phenomena in sediments arise from acoustic wave-induced fluid motion in the pore space, which perturbs the electrostatic equilibrium of the electric double layer on the grain surfaces. Experimental techniques and the apparatus built to study this electrokinetic (EK) effect are described and outcomes for studies of seismoelectric phenomena in loose glass microspheres and medium-grain sand are presented. By varying the NaCl concentration in the pore fluid, we measured the conductivity dependence of two kinds of EK behavior: (1) the electric fields generated within the samples by the passage of transmitted acoustic waves, and (2) the electromagnetic wave produced at the fluid-sediment interface by the incident acoustic wave. Both phenomena are caused by relative fluid motion in the sediment pores--this feature is characteristic of poroelastic (Biot) media, but not predicted by either viscoelastic fluid or solid models. A model of plane-wave reflection from a fluid-sediment interface using EK-Biot theory leads to theoretical predictions that compare well to the experimental data for both sand and glass microspheres.

  7. Physical mechanism of membrane osmotic phenomena

    SciTech Connect

    Guell, D.C.; Brenner, H.

    1996-09-01

    The microscale, physicomechanical cause of osmosis and osmotic pressure in systems involving permeable and semipermeable membranes is not well understood, and no fully satisfactory mechanism has been offered to explain these phenomena. A general theory, albeit limited to dilute systems of inert, noninteracting solute particles, is presented which demonstrates that short-range forces exerted by the membrane on the dispersed solute particles constitute the origin of osmotic phenomena. At equilibrium, the greater total force exerted by the membrane on those solute particles present in the reservoir containing the more concentrated of the two solutions bathing the membrane is balanced by a macroscopically observable pressure difference between the two reservoirs. The latter constitutes the so-called osmotic pressure difference. Under nonequilibrium conditions, the membrane-solute force is transmitted to the solvent, thus driving the convective flow of solvent observed macroscopically as osmosis. While elements of these ideas have been proposed previously in various forms, the general demonstration offered here of the physicomechanical source of osmotic phenomena is novel. Beyond the purely academic interest that exists in establishing a mechanical understanding of osmotic pressure, the analysis lays the foundation underlying a quantitative theory of osmosis in dilute, nonequilibrium systems outlined in a companion paper.

  8. Stability and restoration phenomena in competitive systems

    NASA Astrophysics Data System (ADS)

    Uechi, Lisa; Akutsu, Tatsuya

    2013-10-01

    A conservation law along with stability, recovering phenomena, and characteristic patterns of a nonlinear dynamical system have been studied and applied to physical, biological, and ecological systems. In our previous study, we proposed a system of symmetric 2n-dimensional conserved nonlinear differential equations. In this paper, competitive systems described by a 2-dimensional nonlinear dynamical (ND) model with external perturbations are applied to population cycles and recovering phenomena of systems from microbes to mammals. The famous 10-year cycle of population density of Canadian lynx and snowshoe hare is numerically analyzed. We find that a nonlinear dynamical system with a conservation law is stable and generates a characteristic rhythm (cycle) of population density, which we call the standard rhythm of a nonlinear dynamical system. The stability and restoration phenomena are strongly related to a conservation law and the balance of a system. The standard rhythm of population density is a manifestation of the survival of the fittest to the balance of a nonlinear dynamical system.

  9. An interpretation of passive containment cooling phenomena

    SciTech Connect

    Chung, Bum-Jin; Kang, Chang-Sun,

    1995-09-01

    A simplified interpretation model for the cooling capability of the Westinghouse type PCCS is proposed in this paper. The PCCS domain was phenomenologically divided into 3 regions; water entrance effect region, asymptotic region, and air entrance effect region. The phenomena in the asymptotic region is focused in this paper. Due to the very large height to thickness ratio of the water film, the length of the asymptotic region is estimated to be over 90% of the whole domain. Using the analogy between heat and mass transfer phenomena in a turbulent situation, a new dependent variable combining temperature and vapor mass fraction was defined. The similarity between the PCCS phenomena, which contains the sensible and latent heat transfer, and the buoyant air flow on a vertical heated plate is derived. The modified buoyant coefficient and thermal conductivity were defined. Using these newly defined variable and coefficients, the modified correlation for the interfacial heat fluxes and the ratios of latent heat transfer to sensible heat transfer is established. To verify the accuracy of the correlation, the results of this study were compared with the results of other numerical analyses performed for the same configuration and they are well within the range of 15% difference.

  10. Search for collective phenomena in hadron interactions

    SciTech Connect

    Kokoulina, E. S. Nikitin, V. A. Petukhov, Y. P.; Karpov, A. V. Kutov, A. Ya.

    2010-12-15

    New results of the search for collective phenomena have been obtained and analyzed in the present report. The experimental studies are carried out on U-70 accelerator of IHEP in Protvino. It is suggested that these phenomena can be discovered at the energy range of 50-70 GeV in the extreme multiplicity region since the high-density matter can form in this very region. The collective behavior of secondary particles is considered to manifest itself in the Bose-Einstein condensation of pions, Vavilov-Cherenkov gluon radiation, excess of soft-photon yield, and other unique phenomena. The perceptible peak in the angular distribution has been revealed. It was interpreted as the gluon radiation and so the parton matter refraction index was determined. The new software was designed for the track reconstruction based on Kalman Filter technique. This algorithm allows one to estimate more precisely the track parameters (especially momentum). The search for Bose-Einstein condensation can be continued by using the selected events with the multiplicity of more than eight charged particles. The gluon dominance model predictions have shown good agreement with the multiplicity distribution at high multiplicity and confirmed the guark-gluon medium formation under these conditions.

  11. Further investigations of oblique hypervelocity impact phenomena

    NASA Technical Reports Server (NTRS)

    Schonberg, William P.

    1988-01-01

    The results of a continuing investigation of the phenomena associated with the oblique hypervelocity impact of spherical projectiles onto multi-sheet aluminum structures are described. A series of equations that quantitatively describes these phenomena is obtained through a regression of experimental data. These equations characterize observed ricoshet and penetration damage phenomena in a multi-sheet structure as functions of the geometric parameters of the structure and the diameter, obliquity, and velocity of the impacting projectile. Crater damage observed on the ricochet witness plates is used to determine the sizes and speeds of the ricochet debris particles that caused the damage. It is shown that, in general, the most damaging ricochet debris particle is approximately 0.25 cm (0.10 in) in diameter and travels at the speed of approximately 2.1 km/sec (6,890 ft/sec). The equations necessary for the design of shielding panels that will protect external systems from such ricochet debris damage are also developed. The dimensions of these shielding panels are shown to be strongly dependent on their inclination and on their circumferential distribution around the spacecraft. It is concluded that obliquity effects of high-speed impacts must be considered in the design of any structure exposed to the meteoroid and space debris environment.

  12. Atmospheric holes and small comets

    NASA Astrophysics Data System (ADS)

    Frank, L. A.; Sigwarth, J. B.

    1993-02-01

    Global images of Earth's UV dayglow as gained with an imaging photometer on board Dynamics Explorer 1 exhibit transient decreases, or atmospheric holes, in the dayglow intensities over areas with diameters about 50 km. Features of these atmospheric holes include (1) preferential motion in the east-to-west direction across the sunlit face of Earth, (2) similar diurnal variations in occurrence rates as those for radar meteors, (3) correlation of the occurrence rates with the nonshower rates as determined with forward scatter radar, and (4) larger angular diameters for these atmospheric holes when the spacecraft approaches Earth during its perigee passes. These atmospheric holes are interpreted in terms of obscuration of the dayglow by water clouds from the disruption and subsequent vaporization of small comets at low altitudes above the atmosphere. Supporting evidence for the existence of these small comets is given by their telescopic sighting at greater altitudes before disruption and the detection of water bursts in Earth's upper atmosphere. The small-comet hypothesis and its relationship to geophysical, lunar, and interplanetary phenomena are discussed.

  13. Lidar investigations of atmospheric dynamics

    NASA Astrophysics Data System (ADS)

    Philbrick, C. Russell; Hallen, Hans D.

    2015-09-01

    Ground based lidar techniques using Raleigh and Raman scattering, differential absorption (DIAL), and supercontinuum sources are capable of providing unique signatures to study dynamical processes in the lower atmosphere. The most useful profile signatures of dynamics in the lower atmosphere are available in profiles of time sequences of water vapor and aerosol optical extinction obtained with Raman and DIAL lidars. Water vapor profiles are used to study the scales and motions of daytime convection cells, residual layer bursts into the planetary boundary layer (PBL), variations in height of the PBL layer, cloud formation and dissipation, scale sizes of gravity waves, turbulent eddies, as well as to study the seldom observed phenomena of Brunt-Väisälä oscillations and undular bore waves. Aerosol optical extinction profiles from Raman lidar provide another tracer of dynamics and motion using sequential profiles atmospheric aerosol extinction, where the aerosol distribution is controlled by dynamic, thermodynamic, and photochemical processes. Raman lidar profiles of temperature describe the stability of the lower atmosphere and measure structure features. Rayleigh lidar can provide backscatter profiles of aerosols in the troposphere, and temperature profiles in the stratosphere and mesosphere, where large gravity waves, stratospheric clouds, and noctilucent clouds are observed. Examples of several dynamical features are selected to illustrate interesting processes observed with Raman lidar. Lidar experiments add to our understanding of physical processes that modify atmospheric structure, initiate turbulence and waves, and describe the relationships between energy sources, atmospheric stability parameters, and the observed dynamics.

  14. Atmospheric holes and small comets

    NASA Technical Reports Server (NTRS)

    Frank, L. A.; Sigwarth, J. B.

    1993-01-01

    Global images of Earth's UV dayglow as gained with an imaging photometer on board Dynamics Explorer 1 exhibit transient decreases, or atmospheric holes, in the dayglow intensities over areas with diameters about 50 km. Features of these atmospheric holes include (1) preferential motion in the east-to-west direction across the sunlit face of Earth, (2) similar diurnal variations in occurrence rates as those for radar meteors, (3) correlation of the occurrence rates with the nonshower rates as determined with forward scatter radar, and (4) larger angular diameters for these atmospheric holes when the spacecraft approaches Earth during its perigee passes. These atmospheric holes are interpreted in terms of obscuration of the dayglow by water clouds from the disruption and subsequent vaporization of small comets at low altitudes above the atmosphere. Supporting evidence for the existence of these small comets is given by their telescopic sighting at greater altitudes before disruption and the detection of water bursts in Earth's upper atmosphere. The small-comet hypothesis and its relationship to geophysical, lunar, and interplanetary phenomena are discussed.

  15. HAZARDOUS AIR POLLUTANTS: DRY-DEPOSITION PHENOMENA

    EPA Science Inventory

    Dry-deposition rates were evaluated for two hazardous organic air pollutants, nitrobenzene and perchloroethylene, to determine their potential for removal from the atmosphere to three building material surfaces, cement, tar paper, and vinyl asbestos tile. Dry-deposition experimen...

  16. Atmospheric radiation

    SciTech Connect

    Harshvardhan, M.R. )

    1991-01-01

    Studies of atmospheric radiative processes are summarized for the period 1987-1990. Topics discussed include radiation modeling; clouds and radiation; radiative effects in dynamics and climate; radiation budget and aerosol effects; and gaseous absorption, particulate scattering and surface reflection. It is concluded that the key developments of the period are a defining of the radiative forcing to the climate system by trace gases and clouds, the recognition that cloud microphysics and morphology need to be incorporated not only into radiation models but also climate models, and the isolation of a few important unsolved theoretical problems in atmospheric radiation.

  17. A Comprehensive Analysis of Io's Atmosphere and Torus

    NASA Technical Reports Server (NTRS)

    Schneider, Nicholas M.

    1999-01-01

    This final report describes the results of our NASA/Planetary Atmospheres program studying the atmosphere of Jupiter's moon Io and the plasma torus which it creates. Io is the most volcanically active body in the solar system, and it is embedded deep within the strongest magnetosphere of any planet. This combination of circumstances leads to a host of scientifically compelling phenomena, including (1) an atmosphere out of proportion with such a small object, (2) a correspondingly large atmospheric escape rate, (3) a ring of dense plasma locked in a feedback loop with the atmosphere, and (4) a host of Io-induced emissions from radio bursts to UV auroral spots on Jupiter. This proposal seeks to continue our investigation into the physics connecting these phenomena, with emphasis on Io's atmosphere and plasma torus. The physical processes are clearly of interest for Io, and also other places in the solar system where they are important but not so readily observable.

  18. Atmospheric humidity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water vapor plays a critical role in earth's atmosphere. It helps to maintain a habitable surface temperature through absorption of outgoing longwave radiation, and it transfers trmendous amounts of energy from the tropics toward the poles by absorbing latent heat during evaporation and subsequently...

  19. Atmospheric Waves

    NASA Technical Reports Server (NTRS)

    2007-01-01

    With its Multispectral Visible Imaging Camera (MVIC), half of the Ralph instrument, New Horizons captured several pictures of mesoscale gravity waves in Jupiter's equatorial atmosphere. Buoyancy waves of this type are seen frequently on Earth - for example, they can be caused when air flows over a mountain and a regular cloud pattern forms downstream. In Jupiter's case there are no mountains, but if conditions in the atmosphere are just right, it is possible to form long trains of these small waves. The source of the wave excitation seems to lie deep in Jupiter's atmosphere, below the visible cloud layers at depths corresponding to pressures 10 times that at Earth's surface. The New Horizons measurements showed that the waves move about 100 meters per second faster than surrounding clouds; this is about 25% of the speed of sound on Earth and is much greater than current models of these waves predict. Scientists can 'read' the speed and patterns these waves to learn more about activity and stability in the atmospheric layers below.

  20. Studies of Novel Quantum Phenomena in Ruthenates

    SciTech Connect

    Mao, Zhiqiang

    2011-04-08

    Strongly correlated oxides have been the subject of intense study in contemporary condensed matter physics, and perovskite ruthenates (Sr,Ca)n+1RunO3n+1 have become a new focus in this field. One of important characteristics of ruthenates is that both lattice and orbital degrees of freedom are active and are strongly coupled to charge and spin degrees of freedom. Such a complex interplay of multiple degrees of freedom causes the properties of ruthenates to exhibit a gigantic response to external stimuli under certain circumstances. Magnetic field, pressure, and chemical composition all have been demonstrated to be effective in inducing electronic/magnetic phase transitions in ruthenates. Therefore, ruthenates are ideal candidates for searching for novel quantum phenomena through controlling external parameters. The objective of this project is to search for novel quantum phenomena in ruthenate materials using high-quality single crystals grown by the floating-zone technique, and investigate the underlying physics. The following summarizes our accomplishments. We have focused on trilayered Sr4Ru3O10 and bilayered (Ca1-xSrx)3Ru2O7. We have succeeded in growing high-quality single crystals of these materials using the floating-zone technique and performed systematic studies on their electronic and magnetic properties through a variety of measurements, including resistivity, Hall coefficient, angle-resolved magnetoresistivity, Hall probe microscopy, and specific heat. We have also studied microscopic magnetic properties for some of these materials using neutron scattering in collaboration with Los Alamos National Laboratory. We have observed a number of unusual exotic quantum phenomena through these studies, such as an orbital selective metamagnetic transition, bulk spin valve effect, and a heavy-mass nearly ferromagnetic state with a surprisingly large Wilson ratio. Our work has also revealed underlying physics of these exotic phenomena. Exotic phenomena of correlated

  1. Microgravity Transport Phenomena Experiment (MTPE) Overview

    NASA Technical Reports Server (NTRS)

    Mason, Larry W.

    1999-01-01

    The Microgravity Transport Phenomena Experiment (MTPE) is a fluids experiment supported by the Fundamentals in Biotechnology program in association with the Human Exploration and Development of Space (BEDS) initiative. The MTP Experiment will investigate fluid transport phenomena both in ground based experiments and in the microgravity environment. Many fluid transport processes are affected by gravity. Osmotic flux kinetics in planar membrane systems have been shown to be influenced by gravimetric orientation, either through convective mixing caused by unstably stratified fluid layers, or through a stable fluid boundary layer structure that forms in association with the membrane. Coupled transport phenomena also show gravity related effects. Coefficients associated with coupled transport processes are defined in terms of a steady state condition. Buoyancy (gravity) driven convection interferes with the attainment of steady state, and the measurement of coupled processes. The MTP Experiment measures the kinetics of molecular migration that occurs in fluids, in response to the application of various driving potentials. Three separate driving potentials may be applied to the MTP Experiment fluids, either singly or in combination. The driving potentials include chemical potential, thermal potential, and electrical potential. Two separate fluid arrangements are used to study membrane mediated and bulk fluid transport phenomena. Transport processes of interest in membrane mediated systems include diffusion, osmosis, and streaming potential. Bulk fluid processes of interest include coupled phenomena such as the Soret Effect, Dufour Effect, Donnan Effect, and thermal diffusion potential. MTP Experiments are performed in the Microgravity Transport Apparatus (MTA), an instrument that has been developed specifically for precision measurement of transport processes. Experiment fluids are contained within the MTA fluid cells, designed to create a one dimensional flow geometry

  2. Space Weather Phenomena at the Galilean Satellites

    NASA Astrophysics Data System (ADS)

    Cessateur, Gaël; Barthelemy, Mathieu

    2015-04-01

    In the framework of the JUICE mission, characterization of Galilean satellites atmospheres is a priority. Although Ganymede and Europa possess a faint atmosphere, their exosphere show emissions features due to both solar UV flux as well as precipitating particles. Using the atmospheric model proposed by Marconi (2006,2007), we have developed a model of exospheric emissions by only considering primary collisions. Two regions will be considered for Ganymede, a polar one mainly dominated by oxygen, and an equatorial one with the predominance of water. Model of Europa's atmosphere presents an uniform one dominated by oxygen. Since Ganymede has its own magnetic field, the polar regions are mainly affected by particle precipitations while in case of Europe, the whole atmosphere has to be considered. Comparison with direct observations such as local measurements from Galileo (electronic density), or remote observations with the Hubble Space Telescope in the UV (oxygen lines at 130.5 and 135.5 nm), shows a good agreement which ensures us to provide reasonable constraints for the JUICE mission.

  3. Seasonal Variability of Saturn's Atmosphere

    NASA Technical Reports Server (NTRS)

    Yanamandra-Fisher, Padma A.; Simon, Amy; Delcroix, Marc; Orton, Glenn S.; Trinh, Shirley

    2012-01-01

    The seasonal variability of Saturn's clouds and weather layer, currently displaying a variety of phenomena (convective storms, planetary waves, giant storms and lightning-induced events, etc.) is not yet fully understood. Variations of Saturn's radiance at 5.2 microns, a spectral region dominated by thermal emission in an atmospheric window containing weak gaseous absorption, contain a strong axisymmetric component as well as large discrete features at low and mid-latitudes that are several degrees colder than the planetary average and uncorrelated with features at shorter wavelengths that are dominated by reflected sunlight (Yanamandra-Fisher et al., 2001. Icarus, Vol. 150). The characterization of several fundamental atmospheric properties and processes, however, remains incomplete, namely: How do seasons affect (a) the global distribution of gaseous constituents and aerosols; and (b) temperatures and the stability against convection and large scale-atmospheric transport? Do 5-micron clouds have counterparts at other altitude levels? What changes occur during the emergence of Great White Storms? Data acquired at the NASA/IRTF and NAOJ/Subaru from 1995 - 2011; since 2004, high-resolution multi-spectral and high-spatial imaging data acquired by the NASA/ESA Cassini mission, represents half a Saturnian year or two seasons. With the addition of detailed multi-spectral data sets acquired by amateur observers, we study these dramatic phenomena to better understand the timeline of the evolution of these events. Seasonal (or temporal) trends in the observables such as albedo of the clouds, thermal fields of the atmosphere as function of altitude, development of clouds, hazes and global abundances of various hydrocarbons in the atmosphere can now be modeled. We will present results of our ongoing investigation for the search and characterization of periodicities over half a Saturnian year, based on a non-biased a priori approach and time series techniques (such as

  4. Simulating physical phenomena with a quantum computer

    NASA Astrophysics Data System (ADS)

    Ortiz, Gerardo

    2003-03-01

    In a keynote speech at MIT in 1981 Richard Feynman raised some provocative questions in connection to the exact simulation of physical systems using a special device named a ``quantum computer'' (QC). At the time it was known that deterministic simulations of quantum phenomena in classical computers required a number of resources that scaled exponentially with the number of degrees of freedom, and also that the probabilistic simulation of certain quantum problems were limited by the so-called sign or phase problem, a problem believed to be of exponential complexity. Such a QC was intended to mimick physical processes exactly the same as Nature. Certainly, remarks coming from such an influential figure generated widespread interest in these ideas, and today after 21 years there are still some open questions. What kind of physical phenomena can be simulated with a QC?, How?, and What are its limitations? Addressing and attempting to answer these questions is what this talk is about. Definitively, the goal of physics simulation using controllable quantum systems (``physics imitation'') is to exploit quantum laws to advantage, and thus accomplish efficient imitation. Fundamental is the connection between a quantum computational model and a physical system by transformations of operator algebras. This concept is a necessary one because in Quantum Mechanics each physical system is naturally associated with a language of operators and thus can be considered as a possible model of quantum computation. The remarkable result is that an arbitrary physical system is naturally simulatable by another physical system (or QC) whenever a ``dictionary'' between the two operator algebras exists. I will explain these concepts and address some of Feynman's concerns regarding the simulation of fermionic systems. Finally, I will illustrate the main ideas by imitating simple physical phenomena borrowed from condensed matter physics using quantum algorithms, and present experimental

  5. Rod Driven Frequency Entrainment and Resonance Phenomena.

    PubMed

    Salchow, Christina; Strohmeier, Daniel; Klee, Sascha; Jannek, Dunja; Schiecke, Karin; Witte, Herbert; Nehorai, Arye; Haueisen, Jens

    2016-01-01

    A controversy exists on photic driving in the human visual cortex evoked by intermittent photic stimulation. Frequency entrainment and resonance phenomena are reported for frequencies higher than 12 Hz in some studies while missing in others. We hypothesized that this might be due to different experimental conditions, since both high and low intensity light stimulation were used. However, most studies do not report radiometric measurements, which makes it impossible to categorize the stimulation according to photopic, mesopic, and scotopic vision. Low intensity light stimulation might lead to scotopic vision, where rod perception dominates. In this study, we investigated photic driving for rod-dominated visual input under scotopic conditions. Twelve healthy volunteers were stimulated with low intensity light flashes at 20 stimulation frequencies, leading to rod activation only. The frequencies were multiples of the individual alpha frequency (α) of each volunteer in the range from 0.40 to 2.30(∗)α. Three hundred and six-channel whole head magnetoencephalography recordings were analyzed in time, frequency, and spatiotemporal domains with the Topographic Matching Pursuit algorithm. We found resonance phenomena and frequency entrainment for stimulations at or close to the individual alpha frequency (0.90-1.10(∗)α) and half of the alpha frequency (0.40-0.55(∗)α). No signs of resonance and frequency entrainment phenomena were revealed around 2.00(∗)α. Instead, on-responses at the beginning and off-responses at the end of each stimulation train were observed for the first time in a photic driving experiment at frequencies of 1.30-2.30(∗)α, indicating that the flicker fusion threshold was reached. All results, the resonance and entrainment as well as the fusion effects, provide evidence for rod-dominated photic driving in the visual cortex. PMID:27588002

  6. Displacement phenomena in lectin affinity chromatography.

    PubMed

    Cho, Wonryeon

    2015-10-01

    The work described here examines displacement phenomena that play a role in lectin affinity chromatography and their potential to impact reproducibility. This was achieved using Lycopersicon esculentum lectin (LEL), a lectin widely used in monitoring cancer. Four small identical LEL columns were coupled in series to form a single affinity chromatography system with the last in the series connected to an absorbance detector. The serial affinity column set (SACS) was then loaded with human plasma proteins. At the completion of loading, the column set was disassembled, the four columns were eluted individually, the captured proteins were trypsin digested, the peptides were deglycosylated with PNGase F, and the parent proteins were identified through mass spectral analyses. Significantly different sets of glycoproteins were selected by each column, some proteins appearing to be exclusively bound to the first column while others were bound further along in the series. Clearly, sample displacement chromatography (SDC) occurs. Glycoproteins were bound at different places in the column train, identifying the presence of glycoforms with different affinity on a single glycoprotein. It is not possible to see these phenomena in the single column mode of chromatography. Moreover, low abundance proteins were enriched, which facilitates detection. The great advantage of this method is that it differentiates between glycoproteins on the basis of their binding affinity. Displacement phenomena are concluded to be a significant component of the separation mechanism in heavily loaded lectin affinity chromatography columns. This further suggests that care must be exercised in sample loading of lectin columns to prevent analyte displacement with nonretained proteins. PMID:26348026

  7. Rod Driven Frequency Entrainment and Resonance Phenomena

    PubMed Central

    Salchow, Christina; Strohmeier, Daniel; Klee, Sascha; Jannek, Dunja; Schiecke, Karin; Witte, Herbert; Nehorai, Arye; Haueisen, Jens

    2016-01-01

    A controversy exists on photic driving in the human visual cortex evoked by intermittent photic stimulation. Frequency entrainment and resonance phenomena are reported for frequencies higher than 12 Hz in some studies while missing in others. We hypothesized that this might be due to different experimental conditions, since both high and low intensity light stimulation were used. However, most studies do not report radiometric measurements, which makes it impossible to categorize the stimulation according to photopic, mesopic, and scotopic vision. Low intensity light stimulation might lead to scotopic vision, where rod perception dominates. In this study, we investigated photic driving for rod-dominated visual input under scotopic conditions. Twelve healthy volunteers were stimulated with low intensity light flashes at 20 stimulation frequencies, leading to rod activation only. The frequencies were multiples of the individual alpha frequency (α) of each volunteer in the range from 0.40 to 2.30∗α. Three hundred and six-channel whole head magnetoencephalography recordings were analyzed in time, frequency, and spatiotemporal domains with the Topographic Matching Pursuit algorithm. We found resonance phenomena and frequency entrainment for stimulations at or close to the individual alpha frequency (0.90–1.10∗α) and half of the alpha frequency (0.40–0.55∗α). No signs of resonance and frequency entrainment phenomena were revealed around 2.00∗α. Instead, on-responses at the beginning and off-responses at the end of each stimulation train were observed for the first time in a photic driving experiment at frequencies of 1.30–2.30∗α, indicating that the flicker fusion threshold was reached. All results, the resonance and entrainment as well as the fusion effects, provide evidence for rod-dominated photic driving in the visual cortex. PMID:27588002

  8. BWR core melt progression phenomena: Experimental analyses

    SciTech Connect

    Ott, L.J.

    1992-06-01

    In the BWR Core Melt in Progression Phenomena Program, experimental results concerning severe fuel damage and core melt progression in BWR core geometry are used to evaluate existing models of the governing phenomena. These include control blade eutectic liquefaction and the subsequent relocation and attack on the channel box structure; oxidation heating and hydrogen generation; Zircaloy melting and relocation; and the continuing oxidation of zirconium with metallic blockage formation. Integral data have been obtained from the BWR DF-4 experiment in the ACRR and from BWR tests in the German CORA exreactor fuel-damage test facility. Additional integral data will be obtained from new CORA BWR test, the full-length FLHT-6 BWR test in the NRU test reactor, and the new program of exreactor experiments at Sandia National Laboratories (SNL) on metallic melt relocation and blockage formation. an essential part of this activity is interpretation and use of the results of the BWR tests. The Oak Ridge National Laboratory (ORNL) has developed experiment-specific models for analysis of the BWR experiments; to date, these models have permitted far more precise analyses of the conditions in these experiments than has previously been available. These analyses have provided a basis for more accurate interpretation of the phenomena that the experiments are intended to investigate. The results of posttest analyses of BWR experiments are discussed and significant findings from these analyses are explained. The ORNL control blade/canister models with materials interaction, relocation and blockage models are currently being implemented in SCDAP/RELAP5 as an optional structural component.

  9. BWR core melt progression phenomena: Experimental analyses

    SciTech Connect

    Ott, L.J.

    1992-01-01

    In the BWR Core Melt in Progression Phenomena Program, experimental results concerning severe fuel damage and core melt progression in BWR core geometry are used to evaluate existing models of the governing phenomena. These include control blade eutectic liquefaction and the subsequent relocation and attack on the channel box structure; oxidation heating and hydrogen generation; Zircaloy melting and relocation; and the continuing oxidation of zirconium with metallic blockage formation. Integral data have been obtained from the BWR DF-4 experiment in the ACRR and from BWR tests in the German CORA exreactor fuel-damage test facility. Additional integral data will be obtained from new CORA BWR test, the full-length FLHT-6 BWR test in the NRU test reactor, and the new program of exreactor experiments at Sandia National Laboratories (SNL) on metallic melt relocation and blockage formation. an essential part of this activity is interpretation and use of the results of the BWR tests. The Oak Ridge National Laboratory (ORNL) has developed experiment-specific models for analysis of the BWR experiments; to date, these models have permitted far more precise analyses of the conditions in these experiments than has previously been available. These analyses have provided a basis for more accurate interpretation of the phenomena that the experiments are intended to investigate. The results of posttest analyses of BWR experiments are discussed and significant findings from these analyses are explained. The ORNL control blade/canister models with materials interaction, relocation and blockage models are currently being implemented in SCDAP/RELAP5 as an optional structural component.

  10. Fast Particle Methods for Multiscale Phenomena Simulations

    NASA Technical Reports Server (NTRS)

    Koumoutsakos, P.; Wray, A.; Shariff, K.; Pohorille, Andrew

    2000-01-01

    We are developing particle methods oriented at improving computational modeling capabilities of multiscale physical phenomena in : (i) high Reynolds number unsteady vortical flows, (ii) particle laden and interfacial flows, (iii)molecular dynamics studies of nanoscale droplets and studies of the structure, functions, and evolution of the earliest living cell. The unifying computational approach involves particle methods implemented in parallel computer architectures. The inherent adaptivity, robustness and efficiency of particle methods makes them a multidisciplinary computational tool capable of bridging the gap of micro-scale and continuum flow simulations. Using efficient tree data structures, multipole expansion algorithms, and improved particle-grid interpolation, particle methods allow for simulations using millions of computational elements, making possible the resolution of a wide range of length and time scales of these important physical phenomena.The current challenges in these simulations are in : [i] the proper formulation of particle methods in the molecular and continuous level for the discretization of the governing equations [ii] the resolution of the wide range of time and length scales governing the phenomena under investigation. [iii] the minimization of numerical artifacts that may interfere with the physics of the systems under consideration. [iv] the parallelization of processes such as tree traversal and grid-particle interpolations We are conducting simulations using vortex methods, molecular dynamics and smooth particle hydrodynamics, exploiting their unifying concepts such as : the solution of the N-body problem in parallel computers, highly accurate particle-particle and grid-particle interpolations, parallel FFT's and the formulation of processes such as diffusion in the context of particle methods. This approach enables us to transcend among seemingly unrelated areas of research.

  11. Paramagnetic Meissner effect and related dynamical phenomena

    NASA Astrophysics Data System (ADS)

    Li, Mai Suan

    2003-03-01

    The hallmark of superconductivity is the diamagnetic response to external magnetic field. In striking contrast to this behavior, a paramagnetic response or paramagnetic Meissner effect was observed in ceramic high- Tc and in conventional superconductors. The present review is given on this interesting effect and related phenomena. We begin with a detailed discussion of experimental results on the paramagnetic Meissner effect in both granular and conventional superconductors. There are two main mechanisms leading to the paramagnetic response: the so-called d-wave and the flux compression. In the first scenario, the Josephson critical current between two d-wave superconductors becomes negative or equivalently one has a π junction. The paramagnetic signal occurs due to the nonzero spontaneous supercurrent circulating in a loop consisting of odd number of π junctions. In addition to the d-wave mechanism we present the flux compression mechanism for the paramagnetic Meissner effect. The compression may be due to either an inhomogeneous superconducting transition or flux trap inside the giant vortex state. The flux trapping which acts like a total nonzero spontaneous magnetic moment causes the paramagnetic signal. The anisotropic pairing scenario is believed to be valid for granular materials while the flux trap one can be applied to both conventional and high- Tc superconductors. The study of different phenomena by a three-dimensional lattice model of randomly distributed π Josephson junctions with finite self-inductance occupies the main part of our review. By simulations one can show that the chiral glass phase in which chiralities are frozen in time and in space may occur in granular superconductors possessing d-wave pairing symmetry. Experimental attempts on the search for the chiral glass phase are analysed. Experiments on dynamical phenomena such as AC susceptibility, compensation effect, anomalous microwave absorption, aging effect, AC resistivity and

  12. General unifying features of controlled quantum phenomena

    SciTech Connect

    Pechen, Alexander; Brif, Constantin; Wu, Rebing; Chakrabarti, Raj; Rabitz, Herschel

    2010-09-15

    Many proposals have been put forth for controlling quantum phenomena, including open-loop, adaptive feedback, and real-time feedback control. Each of these approaches has been viewed as operationally, and even physically, distinct from the others. This work shows that all such scenarios inherently share the same fundamental control features residing in the topology of the landscape relating the target physical observable to the applied controls. This unified foundation may provide a basis for development of hybrid control schemes that would combine the advantages of the existing approaches to achieve the best overall performance.

  13. Electronic phenomena in adsorption and catalysis

    SciTech Connect

    Kiselev, V.F.; Krylov, O.V.

    1987-01-01

    This book is the second of a three-volume treatment prepared by a physicist and a chemist, who took a common standpoint in considering the close relationship between the electronic processes taking place on the semiconductor-dielectric interface on the one hand, and the adsorptive and catalytic phenomena on the other. This volume brings together, and generalizes, a vast bulk of knowledge on the nature of surface and interface states, on the mechanism of surface electronic processes in semiconductors, as well as considers ways of controlling these processes. In addition, the authors discuss plausible mechanisms of elementary acts in surface charging during adsorption and catalysis.

  14. Phenomena and Parameters Important to Burnup Credit

    SciTech Connect

    Parks, C.V.

    2001-01-10

    Since the mid-1980s, a significant number of studies have been directed at understanding the phenomena and parameters important to implementation of burnup credit in out-of-reactor applications involving pressurized-water-reactor (PWR) spent fuel. The efforts directed at burnup credit involving boiling-water-reactor (BWR) spent fuel have been more limited. This paper reviews the knowledge and experience gained from work performed in the US and other countries in the study of burnup credit. Relevant physics and analysis phenomenon are identified, and an assessment of their importance to burnup credit implementation for transport and dry cask storage is given.

  15. Complex Synchronization Phenomena in Ecological Systems

    NASA Astrophysics Data System (ADS)

    Stone, Lewi; Olinky, Ronen; Blasius, Bernd; Huppert, Amit; Cazelles, Bernard

    2002-07-01

    Ecological and biological systems provide us with many striking examples of synchronization phenomena. Here we discuss a number of intriguing cases and attempt to explain them taking advantage of a modelling framework. One main focus will concern synchronized ecological end epidemiological cycles which have Uniform Phase growth associated with their regular recurrence, and Chaotic Amplitudes - a feature we term UPCA. Examples come from different areas and include decadal cycles of small mammals, recurrent viral epidemics such as childhood infections (eg., measles), and seasonally driven phytoplankton blooms observed in lakes and the oceans. A more detailed theoretical analysis of seasonally synchronized chaotic population cycles is presented.

  16. Quenching phenomena in natural circulation loop

    SciTech Connect

    Umekawa, Hisashi; Ozawa, Mamoru; Ishida, Naoki

    1995-09-01

    Quenching phenomena has been investigated experimentally using circulation loop of liquid nitrogen. During the quenching under natural circulation, the heat transfer mode changes from film boiling to nucleate boiling, and at the same time flux changes with time depending on the vapor generation rate and related two-phase flow characteristics. Moreover, density wave oscillations occur under a certain operating condition, which is closely related to the dynamic behavior of the cooling curve. The experimental results indicates that the occurrence of the density wave oscillation induces the deterioration of effective cooling of the heat surface in the film and the transition boiling regions, which results in the decrease in the quenching velocity.

  17. Advances in modelling of condensation phenomena

    SciTech Connect

    Liu, W.S.; Zaltsgendler, E.; Hanna, B.

    1997-07-01

    The physical parameters in the modelling of condensation phenomena in the CANDU reactor system codes are discussed. The experimental programs used for thermal-hydraulic code validation in the Canadian nuclear industry are briefly described. The modelling of vapour generation and in particular condensation plays a key role in modelling of postulated reactor transients. The condensation models adopted in the current state-of-the-art two-fluid CANDU reactor thermal-hydraulic system codes (CATHENA and TUF) are described. As examples of the modelling challenges faced, the simulation of a cold water injection experiment by CATHENA and the simulation of a condensation induced water hammer experiment by TUF are described.

  18. Monte Carlo analysis of magnetic aftereffect phenomena

    NASA Astrophysics Data System (ADS)

    Andrei, Petru; Stancu, Alexandru

    2006-04-01

    Magnetic aftereffect phenomena are analyzed by using the Monte Carlo technique. This technique has the advantage that it can be applied to any model of hysteresis. It is shown that a log t-type dependence of the magnetization can be qualitatively predicted even in the framework of hysteresis models with local history, such as the Jiles-Atherton model. These models are computationally much more efficient than the models with global history such as the Preisach model. Numerical results related to the decay of the magnetization as of function of time, as well as to the viscosity coefficient, are presented.

  19. On periodicity of solar wind phenomena

    NASA Technical Reports Server (NTRS)

    Verma, V. K.; Joshi, G. C.

    1995-01-01

    We have investigated the rate of occurrence of solar wind phenomena observed between 1972-1984 using power spectrum analysis. The data have been taken from the high speed solar wind (HSSW) streams catalogue published by Mavromichalaki et al. (1988). The power spectrum analysis of HSSW events indicate that HSSW stream events have a periodicity of 9 days. This periodicity of HSSW events is 1/3 of the 27 days period of coronal holes which are the major source of solar wind events. In our opinion the 9 days period may be the energy build up time to produce the HSSW stream events.

  20. Observations of cometary plasma wave phenomena

    NASA Technical Reports Server (NTRS)

    Scarf, F. L.; Coroniti, F. V.; Kennel, C. F.; Gurnett, D. A.; Ip, W.-H.; Smith, E. J.

    1986-01-01

    The ICE plasma wave investigation utilized very long electric antennas (100 m tip-to-tip) and a very high sensitivity magnetic search coil to obtain significant local information on plasma physics phenomena occurring in the distant pickup regions of Comet Giacobini-Zinner and Comet Halley; and information on the processes that developed in the coma and tail of Giacobini-Zinner. The ICE plasma wave measurements associated with both comet encounters are summarized, and high sensitivity ICE observations are related to corresponding measurements from the other Halley spacecraft.

  1. AIRS - the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Lambrigsten, Bjorn H.; Fetzer, Eric; Fishbein, Evan; Lee, Sung-Yung; Paganao, Thomas

    2004-01-01

    The Atmospheric Infrared Sounder (AIRS) was launched in 2002, along with two companion microwave sounders. This AIRS sounding suite is the most advanced atmospheric sounding system to date, with measurement accuracies far surpassing those of current weather satellites. From its sun synchronous polar orbit, the AIRS system provides more than 90% of the globe every 24 hours. Much of the post-launch period has been devoted to optimizing the 'retrieval' system used to derive atmospheric and other parameters from the observations and to validate those parameters. The geophysical parameters have been produced since the beginning of 2003 - the first data were released to the public in mid-2003, and future improved versions will be released periodically. The ongoing calibration/validation effort has confirmed that the system is very accurate and stable. There are a number of applications for the AIRS products, ranging from numerical weather prediction - where positive impact on forecast accuracy has already been demonstrated, to atmospheric research - where the AIRS water vapor products near the surface and in the mid and upper troposphere as well as in the stratosphere promise to make it possible to characterize and model phenomena that are key for short-term atmospheric processes, from weather patterns to long-term processes, such as interannual variability and climate change.

  2. WHC natural phenomena hazards mitigation implementation plan

    SciTech Connect

    Conrads, T.J.

    1996-09-11

    Natural phenomena hazards (NPH) are unexpected acts of nature which pose a threat or danger to workers, the public or to the environment. Earthquakes, extreme winds (hurricane and tornado),snow, flooding, volcanic ashfall, and lightning strike are examples of NPH at Hanford. It is the policy of U.S. Department of Energy (DOE) to design, construct and operate DOE facilitiesso that workers, the public and the environment are protected from NPH and other hazards. During 1993 DOE, Richland Operations Office (RL) transmitted DOE Order 5480.28, ``Natural Phenomena Hazards Mitigation,`` to Westinghouse Hanford COmpany (WHC) for compliance. The Order includes rigorous new NPH criteria for the design of new DOE facilities as well as for the evaluation and upgrade of existing DOE facilities. In 1995 DOE issued Order 420.1, ``Facility Safety`` which contains the same NPH requirements and invokes the same applicable standards as Order 5480.28. It will supersede Order 5480.28 when an in-force date for Order 420.1 is established through contract revision. Activities will be planned and accomplished in four phases: Mobilization; Prioritization; Evaluation; and Upgrade. The basis for the graded approach is the designation of facilities/structures into one of five performance categories based upon safety function, mission and cost. This Implementation Plan develops the program for the Prioritization Phase, as well as an overall strategy for the implemention of DOE Order 5480.2B.

  3. Animal network phenomena: insights from triadic games

    NASA Astrophysics Data System (ADS)

    Mesterton-Gibbons, Mike; Sherratt, Tom N.

    Games of animal conflict in networks rely heavily on computer simulation because analysis is difficult, the degree of difficulty increasing sharply with the size of the network. For this reason, virtually the entire analytical literature on evolutionary game theory has assumed either dyadic interaction or a high degree of symmetry, or both. Yet we cannot rely exclusively on computer simulation in the study of any complex system. So the study of triadic interactions has an important role to play, because triads are both the simplest groups in which asymmetric network phenomena can be studied and the groups beyond dyads in which analysis of population games is most likely to be tractable, especially when allowing for intrinsic variation. Here we demonstrate how such analyses can illuminate a variety of behavioral phenomena within networks, including coalition formation, eavesdropping (the strategic observation of contests between neighbors) and victory displays (which are performed by the winners of contests but not by the losers). In particular, we show that eavesdropping acts to lower aggression thresholds compared to games without it, and that victory displays to bystanders will be most intense when there is little difference in payoff between dominating an opponent and not subordinating.

  4. Quantum Phenomena Tested By Neutron Interferometry

    SciTech Connect

    Rauch, Helmut

    2005-02-15

    Entanglement of two photons, or atoms is a complementary situation to a double slit situation of a single photon, neutron or atom. With neutrons single particle interference phenomena can be observed and the 'entanglement of degrees of freedom', i.e. contextuality can be verified. In this respect, neutrons are proper tools for testing quantum mechanics because they are massive, they couple to electromagnetic fields due to their magnetic moment and they are subject to all basic interactions, and they are sensitive to topological effects, as well. Related experiments will be discussed. Deterministic and stochastic partial absorption experiments can be described by Bell-type inequalities. Recent neutron interferometry experiments based on postselection methods renewed the discussion about quantum nonlocality and the quantum measuring process. It has been shown that interference phenomena can be revived even when the overall interference pattern has lost its contrast. This indicates a persisting coupling in phase space even in cases of spatially separated Schroedinger cat-like situations. These states are extremely fragile and sensitive against any kind of fluctuations and other decoherence processes. More complete quantum experiments also show that a complete retrieval of quantum states behind an interaction volume becomes impossible in principle.

  5. Effects of electrostatic correlations on electrokinetic phenomena.

    PubMed

    Storey, Brian D; Bazant, Martin Z

    2012-11-01

    The classical theory of electrokinetic phenomena is based on the mean-field approximation that the electric field acting on an individual ion is self-consistently determined by the local mean charge density. This paper considers situations, such as concentrated electrolytes, multivalent electrolytes, or solvent-free ionic liquids, where the mean-field approximation breaks down. A fourth-order modified Poisson equation is developed that captures the essential features in a simple continuum framework. The model is derived as a gradient approximation for nonlocal electrostatics of interacting effective charges, where the permittivity becomes a differential operator, scaled by a correlation length. The theory is able to capture subtle aspects of molecular simulations and allows for simple calculations of electrokinetic flows in correlated ionic fluids. Charge-density oscillations tend to reduce electro-osmotic flow and streaming current, and overscreening of surface charge can lead to flow reversal. These effects also help to explain the suppression of induced-charge electrokinetic phenomena at high salt concentrations. PMID:23214872

  6. Physical phenomena and the microgravity response

    NASA Technical Reports Server (NTRS)

    Todd, Paul

    1989-01-01

    The living biological cell is not a sack of Newtonian fluid containing systems of chemical reactions at equilibrium. It is a kinetically driven system, not a thermodynamically driven system. While the cell as a whole might be considered isothermal, at the scale of individual macromolecular events there is heat generated, and presumably sharp thermal gradients exist at the submicron level. Basic physical phenomena to be considered when exploring the cell's response to inertial acceleration include particle sedimentation, solutal convection, motility electrokinetics, cytoskeletal work, and hydrostatic pressure. Protein crystal growth experiments, for example, illustrate the profound effects of convection currents on macromolecular assembly. Reaction kinetics in the cell vary all the way from diffusion-limited to life-time limited. Transport processes vary from free diffusion, to facilitated and active transmembrane transport, to contractile-protein-driven motility, to crystalline immobilization. At least four physical states of matter exist in the cell: aqueous, non-aqueous, immiscible-aqueous, and solid. Levels of order vary from crystalline to free solution. The relative volumes of these states profoundly influence the cell's response to inertial acceleration. Such subcellular phenomena as stretch-receptor activation, microtubule re-assembly, synaptic junction formation, chemotactic receptor activation, and statolith sedimentation were studied recently with respect to both their basic mechanisms and their responsiveness to inertial acceleration. From such studies a widespread role of cytoskeletal organization is becoming apparent.

  7. Mathematical methods of studying physical phenomena

    NASA Astrophysics Data System (ADS)

    Man'ko, Margarita A.

    2013-03-01

    In recent decades, substantial theoretical and experimental progress was achieved in understanding the quantum nature of physical phenomena that serves as the foundation of present and future quantum technologies. Quantum correlations like the entanglement of the states of composite systems, the phenomenon of quantum discord, which captures other aspects of quantum correlations, quantum contextuality and, connected with these phenomena, uncertainty relations for conjugate variables and entropies, like Shannon and Rényi entropies, and the inequalities for spin states, like Bell inequalities, reflect the recently understood quantum properties of micro and macro systems. The mathematical methods needed to describe all quantum phenomena mentioned above were also the subject of intense studies in the end of the last, and beginning of the new, century. In this section of CAMOP 'Mathematical Methods of Studying Physical Phenomena' new results and new trends in the rapidly developing domain of quantum (and classical) physics are presented. Among the particular topics under discussion there are some reviews on the problems of dynamical invariants and their relations with symmetries of the physical systems. In fact, this is a very old problem of both classical and quantum systems, e.g. the systems of parametric oscillators with time-dependent parameters, like Ermakov systems, which have specific constants of motion depending linearly or quadratically on the oscillator positions and momenta. Such dynamical invariants play an important role in studying the dynamical Casimir effect, the essence of the effect being the creation of photons from the vacuum in a cavity with moving boundaries due to the presence of purely quantum fluctuations of the electromagnetic field in the vacuum. It is remarkable that this effect was recently observed experimentally. The other new direction in developing the mathematical approach in physics is quantum tomography that provides a new vision of

  8. Atmospheric Dynamics

    NASA Astrophysics Data System (ADS)

    Green, John

    2004-12-01

    In his book, John Green presents a unique personal insight into the fundamentals of fluid mechanics and atmospheric dynamics. Generations of students have benefited from his lectures, and this book, many years in the making, is the result of his wide teaching and research experience. The theory of fluid flow has developed to such an extent that very complex mathematics and models are currently used to describe it, but many of the fundamental results follow from relatively simple considerations: these classic principles are derived here in a novel, distinctive, and at times even idiosyncratic, way. The book is an introduction to fluid mechanics in the atmosphere for students and researchers that are already familiar with the subject, but who wish to extend their knowledge and philosophy beyond the currently popular development of conventional undergraduate instruction.

  9. Atmospheric neutrinos

    NASA Astrophysics Data System (ADS)

    Gaisser, Thomas K.

    2016-05-01

    In view of the observation by IceCube of high-energy astrophysical neutrinos, it is important to quantify the uncertainty in the background of atmospheric neutrinos. There are two sources of uncertainty, the imperfect knowledge of the spectrum and composition of the primary cosmic rays that produce the neutrinos and the limited understanding of hadron production, including charm, at high energy. This paper is an overview of both aspects.

  10. Atmospheric Aerosols

    NASA Technical Reports Server (NTRS)

    Pueschel, R. F.; Lawless, James G. (Technical Monitor)

    1994-01-01

    Aerosols, defined as particles and droplets suspended in air, are always present in the atmosphere. They are part of the earth-atmosphere climate system, because they interact with both incoming solar and outgoing terrestrial radiation. They do this directly through scattering and absorption, and indirectly through effects on clouds. Submicrometer aerosols usually predominate in terms of number of particles per unit volume of air. They have dimensions close to the wavelengths of visible light, and thus scatter radiation from the sun very effectively. They are produced in the atmosphere by chemical reactions of sulfur-, nitrogen- and carbon-containing gases of both natural and anthropogenic origins. Light absorption is dominated by particles containing elemental carbon (soot), produced by incomplete combustion of fossil fuels and by biomass burning. Light-scattering dominates globally, although absorption can be significant at high latitudes, particularly over highly reflective snow- or ice-covered surfaces. Other aerosol substances that may be locally important are those from volcanic eruptions, wildfires and windblown dust.

  11. Collective Phenomena In Volume And Surface Barrier Discharges

    NASA Astrophysics Data System (ADS)

    Kogelschatz, U.

    2010-07-01

    Barrier discharges are increasingly used as a cost-effective means to produce non-equilibrium plasmas at atmospheric pressure. This way, copious amounts of electrons, ions, free radicals and excited species can be generated without appreciable gas heating. In most applications the barrier is made of dielectric material. In laboratory experiments also the use of resistive, ferroelectric and semiconducting materials has been investigated, also porous ceramic layers and dielectric barriers with controlled surface conductivity. Major applications utilizing mainly dielectric barriers include ozone generation, surface cleaning and modification, polymer and textile treatment, sterilization, pollution control, CO2 lasers, excimer lamps, plasma display panels (flat TV screens). More recent research efforts are also devoted to biomedical applications and to plasma actuators for flow control. Sinu- soidal feeding voltages at various frequencies as well as pulsed excitation schemes are used. Volume as well as surface barrier discharges can exist in the form of filamentary, regularly patterned or laterally homogeneous discharges. Reviews of the subject and the older literature on barrier discharges were published by Kogelschatz (2002, 2003), by Wagner et al. (2003) and by Fridman et al. (2005). A detailed discussion of various properties of barrier discharges can also be found in the recent book "Non-Equilibrium Air Plasmas at Atmospheric Pressure" by Becker et al. (2005). The physical effects leading to collective phenomena in volume and surface barrier discharges will be discussed in detail. Special attention will be given to self-organization of current filaments. Main similarities and differences of the two types of barrier discharges will be elaborated.

  12. Astrophysical phenomena related to supermassive black holes

    NASA Astrophysics Data System (ADS)

    Pott, Jörg-Uwe

    2006-12-01

    The thesis contains the results of my recent projects in astrophysical research. All projects aim at pushing the limits of our knowledge about the interaction between a galaxy, the fundamental building block of today's universe, and a supermassive black hole (SMBH) at its center. Over the past years a lot of observational evidence has been gathered for the current understanding, that at least a major part of the galaxies with a stellar bulge contain central SMBHs. The typical extragalactic approach consists of searching for the spectroscopic pattern of Keplerian rotation, produced by stars and gas, when orbiting a central dark mass (Kormendy & Richstone 1995). It suggests that a significant fraction of large galaxies host in their very nucleus a SMBH of millions to billions of solar masses (Kormendy & Gebhardt 2001). In the closest case, the center of our Milky Way, the most central stars, which can be imaged, were shown to move on orbits with circulation times of a few decades only, evidencing a mass and compactness of the dark counter part of the Keplerian motion, which can only be explained by a SMBH (Eckart & Genzel 1996; Ghez et al. 2000; Schödel et al. 2002). Having acknowledged the widespread existence of SMBHs the obvious next step is investigating the interaction with their environment. Although the basic property of a SMBH, which is concentrating a huge amount of mass in a ludicrously small volume defined by the Schwarzschild radius, only creates a deep gravitational trough, its existence evokes much more phenomena than simply attracting the surrounding matter. It can trigger or exacerbate star formation via tidal forces (Morris 1993). It shapes the distribution of its surrounding matter to accretion discs, which themselves release gravitational potential energy as radiation, possibly due to magnetic friction (Blandford 1995). The radiation efficiency of such active galactic nuclei (AGN) can become roughly 100 times more efficient than atomic nuclear

  13. Microgravity Transport Phenomena Experiment (MTPE) Overview

    NASA Technical Reports Server (NTRS)

    Mason, Larry W.

    1999-01-01

    The Microgravity Transport Phenomena Experiment (MTPE) is a fluids experiment supported by the Fundamentals in Biotechnology program in association with the Human Exploration and Development of Space (BEDS) initiative. The MTP Experiment will investigate fluid transport phenomena both in ground based experiments and in the microgravity environment. Many fluid transport processes are affected by gravity. Osmotic flux kinetics in planar membrane systems have been shown to be influenced by gravimetric orientation, either through convective mixing caused by unstably stratified fluid layers, or through a stable fluid boundary layer structure that forms in association with the membrane. Coupled transport phenomena also show gravity related effects. Coefficients associated with coupled transport processes are defined in terms of a steady state condition. Buoyancy (gravity) driven convection interferes with the attainment of steady state, and the measurement of coupled processes. The MTP Experiment measures the kinetics of molecular migration that occurs in fluids, in response to the application of various driving potentials. Three separate driving potentials may be applied to the MTP Experiment fluids, either singly or in combination. The driving potentials include chemical potential, thermal potential, and electrical potential. Two separate fluid arrangements are used to study membrane mediated and bulk fluid transport phenomena. Transport processes of interest in membrane mediated systems include diffusion, osmosis, and streaming potential. Bulk fluid processes of interest include coupled phenomena such as the Soret Effect, Dufour Effect, Donnan Effect, and thermal diffusion potential. MTP Experiments are performed in the Microgravity Transport Apparatus (MTA), an instrument that has been developed specifically for precision measurement of transport processes. Experiment fluids are contained within the MTA fluid cells, designed to create a one dimensional flow geometry

  14. Electrical breakdown caused by dust motion in low-pressure atmospheres: considerations for Mars.

    PubMed

    Eden, H F; Vonnegut, B

    1973-06-01

    Electrification of agitated dust can cause visible breakdown in a carbon dioxide atmosphere at low pressure in a laboratory experiment. Dust storms on earth become electrified, with accompanying breakdown phenomena. Martian dust storms may reduce the atmospheric conductivity by capturing fast ions on particles, and, by electrifying, may cause discharges in the relatively low pressure atmosphere. PMID:17735929

  15. Features of optical phenomena connected with launches of solid-propellant ballistic rockets

    NASA Astrophysics Data System (ADS)

    Platov, Yu. V.; Chernouss, S. A.; Alpatov, V. V.

    2013-04-01

    Specific optical phenomena observed in the upper atmosphere layers and connected with launches of powerful solid-propellant rockets are considered: the development of spherically symmetric gas-dust formations having the shape of an extending torus in the image plane and the formation of regions with intense blue-green (turquoise) glow observed under twilight conditions along a rocket's flight path. The development of clouds can be represented by the model of a strong explosion occurring at the stage separation of solid-propellant rockets in the upper atmosphere. A turquoise glow arises as a result of resonance scattering of solar radiation on AlO molecules that are formed when metallic aluminum in the composition of fuel interacts with atmosphere components and combustion products.

  16. EZ lidar dust transit phenomena observations in Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Lolli, S.; Sauvage, L.; Loaec, S.

    2009-09-01

    Duststorms and sandstorms regularly devastate Northeast Asia and cause considerable damage to transportation system and public health; further, these events are conceived to be one of the very important indices for estimating the global warming and desertification. Previously, yellow sand events were considered natural phenomena that originate in deserts and arid areas. However, the greater scale and frequency of these events in recent years are considered to be the result of human activities such as overgrazing and over-cultivation. Japan, Korea, Cina and Mongolia are directly concerned to prevent and control these storms and have been able to some extent to provide forecasts and early warnings. In this framework, to improve the accuracy of forecasting , a compact and rugged eye safe lidar, the EZ LIDATM, developed together by Laboratoire des Sciences du Climat et l'Environnement (LSCE) (CEA-CNRS) and LEOSPHERE, France) to study and investigate structural and optical properties of clouds and aerosols, thanks to the strong know-how of CEA and CNRS in the field of air quality measurements and cloud observation and analysis, was deployed in Seoul, Korea in order to detect and study yellow sand events, thanks to its depolarization channel and scan capabilities. The preliminary results, showed in this paper, of this measurement campaign put in evidence that EZ Lidar, for its capabilities of operating unattended day and night under each atmospheric condition, is mature to be deployed in a global network to study long-range transport, crucial in the forecasting model.

  17. Collective phenomena in volume and surface barrier discharges

    NASA Astrophysics Data System (ADS)

    Kogelschatz, U.

    2010-11-01

    Barrier discharges are increasingly used as a cost-effective configuration to produce non-equilibrium plasmas at atmospheric pressure. This way, copious amounts of electrons, ions, free radicals and excited species can be generated without significant heating of the background gas. In most applications the barrier is made of dielectric material. Major applications utilizing mainly dielectric barriers include ozone generation, surface cleaning and modification, polymer and textile treatment, sterilization, pollution control, CO2 lasers, excimer lamps, plasma display panels (flat TV screens). More recent research efforts are devoted to biomedical applications and to plasma actuators for flow control. Sinusoidal feeding voltages at various frequencies as well as pulsed excitation schemes are used. Volume as well as surface barrier discharges can exist in the form of filamentary, regularly patterned or diffuse, laterally homogeneous discharges. The physical effects leading to collective phenomena in volume and surface barrier discharges are discussed in detail. Special attention is paid to self-organization of current filaments and pattern formation. Major similarities of the two types of barrier discharges are elaborated.

  18. Establishment of the New Ecuadorian Solar Physics Phenomena Division

    NASA Astrophysics Data System (ADS)

    Lopez, E. D.

    2014-02-01

    Crucial physical phenomena occur in the equatorial atmosphere and ionosphere, which are currently understudied and poorly understood. Thus, scientific campaigns for monitoring the equatorial region are required in order to provide the necessary data for the physical models. Ecuador is located in strategic geographical position where these studies can be performed, providing quality data for the scientific community working in understanding the nature of these physical systems. The Quito Astronomical Observatory of National Polytechnic School is moving in this direction by promoting research in space sciences for the study of the equatorial zone. With the participation and the valuable collaboration of international initiatives such us AWESOME, MAGDAS, SAVNET and CALLISTO, the Quito Observatory is establishing a new space physics division on the basis of the International Space Weather Initiative. In this contribution, the above initiative is presented by inviting leaders of other scientific projects to deploy its instruments and to work with us providing the necessary support to the creation of this new strategic research center

  19. Visualization of Boiling Phenomena in Inclined Rectangular Gap

    SciTech Connect

    J. L. Rempe

    2005-05-01

    An experimental study was performed to investigate the pool boiling critical heat flux (CHF) in one-dimensional inclined rectangular channels by changing the orientation of a copper test heater assembly. In a pool of saturated water under the atmospheric pressure, the test parameters include the gap sizes of 1, 2, 5, and 10 mm, and the surface orientation angles from the downward-facing position (1800) to the vertical position (90º), respectively. Tests were conducted on the basis of the visualization of boiling phenomena in the narrowly confined channel and open periphery utilizing a high-speed digital camera. To prevent the heat loss from the water pool and copper test heater, a state-of-the-art vacuum pumping technique was introduced. It was observed that the CHF generally decreases as the surface inclination angle increases and as the gap size decreases. In the downward-facing position (180o), however, the vapor movement was enhanced by the gap structure, which produced the opposing result, say, the CHF increases as the gap size decreases. Phenomenological characteristics regarding the interfacial instability of vapor layer were addressed in terms of visualization approaching the CHF. It was found that there exists a transition angle, around which the CHF changes with a rapid slope.

  20. Threshold Phenomena in a Throbbing Complex Plasma

    SciTech Connect

    Mikikian, Maxime; Coueedel, Lenaiec; Cavarroc, Marjorie; Tessier, Yves; Boufendi, Laiefa

    2010-08-13

    In complex plasmas, the trapped dust particle cloud is often characterized by a central dust-free region ('void'). The void induces a spatial inhomogeneity of the dust particle distribution and is at the origin of many intricate unstable phenomena. One type of this kind of behavior is the so-called heartbeat instability consisting of successive contractions and expansions of the void. This instability is characterized by a strong nonlinear dynamics which can reveal the occurrence of incomplete sequences corresponding to failed contractions. Experimental results based on high-speed imaging are presented for the first time and underline this threshold effect in both the dust cloud motion and the evolution of the plasma light emission.

  1. Electron Acceleration by Transient Ion Foreshock Phenomena

    NASA Astrophysics Data System (ADS)

    Wilson, L. B., III; Turner, D. L.

    2015-12-01

    Particle acceleration is a topic of considerable interest in space, laboratory, and astrophysical plasmas as it is a fundamental physical process to all areas of physics. Recent THEMIS [e.g., Turner et al., 2014] and Wind [e.g., Wilson et al., 2013] observations have found evidence for strong particle acceleration at macro- and meso-scale structures and/or pulsations called transient ion foreshock phenomena (TIFP). Ion acceleration has been extensively studied, but electron acceleration has received less attention. Electron acceleration can arise from fundamentally different processes than those affecting ions due to differences in their gyroradii. Electron acceleration is ubiquitous, occurring in the solar corona (e.g., solar flares), magnetic reconnection, at shocks, astrophysical plasmas, etc. We present new results analyzing the dependencies of electron acceleration on the properties of TIFP observed by the THEMIS spacecraft.

  2. Teaching wave phenomena via biophysical applications

    NASA Astrophysics Data System (ADS)

    Reich, Daniel; Robbins, Mark; Leheny, Robert; Wonnell, Steven

    2014-03-01

    Over the past several years we have developed a two-semester second-year physics course sequence for students in the biosciences, tailored in part to the needs of undergraduate biophysics majors. One semester, ``Biological Physics,'' is based on the book of that name by P. Nelson. This talk will focus largely on the other semester, ``Wave Phenomena with Biophysical Applications,'' where we provide a novel introduction to the physics of waves, primarily through the study of experimental probes used in the biosciences that depend on the interaction of electromagnetic radiation with matter. Topic covered include: Fourier analysis, sound and hearing, diffraction - culminating in an analysis of x-ray fiber diffraction and its use in the determination of the structure of DNA - geometrical and physical optics, the physics of modern light microscopy, NMR and MRI. Laboratory exercises tailored to this course will also be described.

  3. Critical and resonance phenomena in neural networks

    NASA Astrophysics Data System (ADS)

    Goltsev, A. V.; Lopes, M. A.; Lee, K.-E.; Mendes, J. F. F.

    2013-01-01

    Brain rhythms contribute to every aspect of brain function. Here, we study critical and resonance phenomena that precede the emergence of brain rhythms. Using an analytical approach and simulations of a cortical circuit model of neural networks with stochastic neurons in the presence of noise, we show that spontaneous appearance of network oscillations occurs as a dynamical (non-equilibrium) phase transition at a critical point determined by the noise level, network structure, the balance between excitatory and inhibitory neurons, and other parameters. We find that the relaxation time of neural activity to a steady state, response to periodic stimuli at the frequency of the oscillations, amplitude of damped oscillations, and stochastic fluctuations of neural activity are dramatically increased when approaching the critical point of the transition.

  4. Equatorial phenomena in neutral thermospheric composition.

    NASA Technical Reports Server (NTRS)

    Reber, C. A.; Hedin, A. E.; Chandra, S.

    1973-01-01

    Several interesting phenomena relating to the equatorial ionosphere have been observed in the data from the OGO-6 mass spectrometer. The diurnal variations during equinox at an altitude of 450 km show the N2 and O densities peaking near 1500 hr while He peaks near 1000 hr. The latitudinal variation in N2 during the day is very similar to the F-region electron density exhibiting the well known features of the ionospheric anomaly. During periods of intense geomagnetic disturbance (e.g. the large storm of 8 March 1970), the low latitude thermospheric temperature increases on the order of 50-150 K, while at mid latitudes, increases of more than 1000 K are observed.

  5. Topological Spintronics: Materials, Phenomena and Devices

    NASA Astrophysics Data System (ADS)

    Samarth, Nitin

    2015-03-01

    The two-dimensional surface states of three-dimensional topological insulators such as Bi2Se3and(Bi,Sb)2Te3 possess a spin texture that can potentially be exploited for spintronics applications. We provide a perspective on the emergence of ``topological spintronics,'' demonstrating how this spin texture can be engineered using either quantum tunneling between surfaces or by breaking time-reversal symmetry. We then discuss recent experiments that show striking spintronic phenomena useful for proof-of-concept devices, including a spin-orbit torque of record efficiency at room temperature and an electrically-gated ``giant anisotropic magnetoresistance'' at low temperature. This work was carried out in collaboration with A. Richardella, S.-Y. Xu, M. Neupane, A. Mellnik, A. Kandala, J. S. Lee, D. M. Zhang, M. Z. Hasan and D. C. Ralph. We acknowledge funding from the DARPA Meso program, ONR and C-SPIN (under sponsorship of MARCO and DARPA).

  6. Transient Phenomena: Opportunities for New Discoveries

    NASA Astrophysics Data System (ADS)

    Lazio, T. Joseph W.

    Known classes of radio wavelength transients range from the nearby (stellar flares and radio pulsars) to the distant Universe (γ-ray burst afterglows). Hypothesized classes of radio transients include analogs of known objects, such as extrasolar planets emitting Jovian-like radio bursts and giant-pulse emitting pulsars in other galaxies, to the exotic, such as prompt emission from γ-ray bursts, evaporating black holes and transmitters from other civilizations. Time domain astronomy has been recognized internationally as a means of addressing key scientific questions in astronomy and physics, and pathfinders and Precursors to the Square Kilometre Array (SKA) are beginning to offer a combination of wider fields of view and more wavelength agility than has been possible in the past. These improvements will continue when the SKA itself becomes operational. I illustrate the range of transient phenomena and discuss how the detection and study of radio transients will improve immensely.

  7. Transient Phenomena: Opportunities for New Discoveries

    NASA Technical Reports Server (NTRS)

    Lazio, T. Joseph W.

    2010-01-01

    Known classes of radio wavelength transients range from the nearby (stellar flares and radio pulsars) to the distant Universe (gamma-ray burst afterglows). Hypothesized classes of radio transients include analogs of known objects, such as extrasolar planets emitting Jovian-like radio bursts and giant-pulse emitting pulsars in other galaxies, to the exotic, such as prompt emission from gamma-ray bursts, evaporating black holes and transmitters from other civilizations. Time domain astronomy has been recognized internationally as a means of addressing key scientific questions in astronomy and physics, and pathfinders and Precursors to the Square Kilometre Array (SKA) are beginning to offer a combination of wider fields of view and more wavelength agility than has been possible in the past. These improvements will continue when the SKA itself becomes operational. I illustrate the range of transient phenomena and discuss how the detection and study of radio transients will improve immensely.

  8. Pump instability phenomena generated by fluid forces

    NASA Technical Reports Server (NTRS)

    Gopalakrishnan, S.

    1985-01-01

    Rotor dynamic behavior of high energy centrifugal pumps is significantly affected by two types of fluid forces; one due to the hydraulic interaction of the impeller with the surrounding volute or diffuser and the other due to the effect of the wear rings. The available data on these forces is first reviewed. A simple one degree-of-freedom system containing these forces is analytically solved to exhibit the rotor dynamic effects. To illustrate the relative magnitude of these phenomena, an example of a multistage boiler feed pump is worked out. It is shown that the wear ring effects tend to suppress critical speed and postpone instability onset. But the volute-impeller forces tend to lower the critical speed and the instability onset speed. However, for typical boiler feed pumps under normal running clearances, the wear ring effects are much more significant than the destabilizing hydraulic interaction effects.

  9. Using Spatial Gradients to Model Localization Phenomena

    SciTech Connect

    D.J.Bammann; D.Mosher; D.A.Hughes; N.R.Moody; P.R.Dawson

    1999-07-01

    We present the final report on a Laboratory-Directed Research and Development project, Using Spatial Gradients to Model Localization Phenomena, performed during the fiscal years 1996 through 1998. The project focused on including spatial gradients in the temporal evolution equations of the state variables that describe hardening in metal plasticity models. The motivation was to investigate the numerical aspects associated with post-bifurcation mesh dependent finite element solutions in problems involving damage or crack propagation as well as problems in which strain Localizations occur. The addition of the spatial gradients introduces a mathematical length scale that eliminates the mesh dependency of the solution. In addition, new experimental techniques were developed to identify the physical mechanism associated with the numerical length scale.

  10. Lunar orbital photography of astronomical phenomena.

    NASA Technical Reports Server (NTRS)

    Mercer, R. D.; Dunkelman, L.; Ross, C. L.; Worden, A.

    1972-01-01

    This paper reports further progress on photography of faint astronomical and geophysical phenomena accomplished during the recent Apollo missions. Command module pilots have been able to photograph such astronomical objects as the solar corona, zodiacal light-corona transition region, lunar libration region, and portions of the Milky Way. The methods utilized for calibration of the film by adaptation of the High Altitude Observatory sensitometer are discussed. Kodak 2485 high-speed recording film was used in both 35-mm and 70-mm formats. The cameras used were Nikon f/1.2 55-mm focal length and Hasselblad f/2.8 80-mm focal length. Preflight and postflight calibration exposures were included on both the flight and control films, corresponding to luminances extending from the inner solar corona to as faint as 1/10 of the luminance of the light of the night sky. The photographs obtained from unique vantage points available during lunar orbit are discussed.