Science.gov

Sample records for atmospheric phenomena

  1. Some atmospheric optical phenomena

    NASA Astrophysics Data System (ADS)

    Malherbe, Jean-Marie

    1988-10-01

    Atmospheric optical effects resulting from the interaction between extended light sources (the sun and moon) or point sources (planets and bright stars) and the heterogeneous atmosphere are discussed. It is noted that refraction is responsible for such phenomena as the oblateness of the sun and moon when rising or setting, mirages (the curving of light rays near the ground), nocturnal scintillation, rainbows, and halos. The diffusion of light by particles in the atmosphere is responsible for the blue color of the sky during the day and the red color of the sky at sunrise and sunset. Diffractive phenomena discussed include the colored ring surrounding the sun or moon when viewed through fog and the iridescent Bishop's ring.

  2. 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.

  3. Atmospheric phenomena before and during sunset.

    PubMed

    Menat, M

    1980-10-15

    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. PMID:20234641

  4. Luminous Phenomena - A Scientific Investigation of Anomalous Luminous Atmospheric Phenomena

    NASA Astrophysics Data System (ADS)

    Teodorani, M.

    2003-12-01

    Anomalous atmospheric luminous phenomena reoccur in several locations of Earth, in the form of multi-color light balls characterized by large dimensions, erratic motion, long duration and a correlated electromagnetic field. The author (an astrophysicist) of this book, which is organized as a selection of some of his technical and popularizing papers and seminars, describes and discusses all the efforts that have been done in 10 years, through several missions and a massive data analysis, in order to obtain some scientific explanation of this kind of anomalies, in particular the Hessdalen anomaly in Norway. The following topics are treated in the book: a) geographic archive of the areas of Earth where such phenomena are known to reoccur most often; b) observational techniques of astrophysical kind that have been used to acquire the data; c) main scientific results obtained so far; d) physical interpretation and natural hypothesis vs. ETV hypothesis; e) historical and chronological issues; f) the importance to brindle new energy sources; g) the importance to keep distance from any kind of "ufology". An unpublished chapter is entirely devoted to a detailed scientific investigation project of light phenomena reoccurring on the Ontario lake; the chosen new-generation multi-wavelength sensing instrumentation that is planned to be used in future missions in that specific area, is described together with scientific rationale and planned procedures. The main results, which were obtained in other areas of the world, such as the Arizona desert, USA and the Sibillini Mountains, Italy, are also briefly mentioned. One chapter is entirely dedicated to the presentation of extensive abstracts of technical papers by the author concerning this specific subject. The book is accompanied with a rich source of bibliographic references.

  5. 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.

  6. Single event phenomena in atmospheric neutron environments

    SciTech Connect

    Gossett, C.A.; Hughlock, B.W.; Katoozi, M.; LaRue, G.S. ); Wender, S.A. )

    1993-12-01

    As integrated circuit technology achieves higher density through smaller feature sizes and as the airplane manufacturing industry integrates more sophisticated electronic components into the design of new aircraft, it has become increasingly important to evaluate the contribution of single event effects, primarily Single Event Upset (SEU), to the safety and reliability of commercial aircraft. In contrast to the effects of radiation on electronic systems in space applications for which protons and heavy ions are of major concern, in commercial aircraft applications the interactions of high energy neutrons are the dominant cause of single event effects. These high energy neutrons are produced by the interaction of solar and galactic cosmic rays, principally protons and heavy ions, in the upper atmosphere. This paper will describe direct experimental measurements of neutron-induced Single Event Effect (SEE) rates in commercial high density static random access memories in a neutron environment characteristic of that at commercial airplane altitudes. The first experimental measurements testing current models for neutron-silicon burst generation rates will be presented, as well as measurements of charge collection in silicon test structures as a function of neutron energy. These are the first laboratory SEE and charge collection measurements using a particle beam having a continuum energy spectrum and with a shape nearly identical to that observed during flight.

  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. 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.

  9. 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]).

  10. 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.

  11. 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.

  12. On recently studied possible atmospheric and ionospheric earthquake precursors and proposed physical mechanisms causing these phenomena

    NASA Astrophysics Data System (ADS)

    Meister, C.-V.; Hoffmann, D. H. H.; Liperovsky, V. A.; Liperovskaya, E. V.

    2010-05-01

    About 20 years ago, a massive search for new, atmospheric and ionospheric precursors of earthquakes began. The aim was to improve the shorttime prediction of earthquakes, which seemed to be impossible using only traditional methods of prediction. Meanwhile, one knows a dozen of new presursors. One investigates thermodynamic parameters of the atmosphere, for instance temperature profiles and humidity, one studies the emanation of gases in seismo-active regions, considers biological and geochemical processes. A lot of work was performed to analyse electromagnetic phenomena occurring before earthquakes. The propagation of infrasound and seismo-gravity waves was investigated. Characteristic parameters of the atmosphere, for instance the foF2-, foE-, and fbEs-frequencies, were analysed, and Es-spread and F-spread on the ionogrammes of vertical sounding stations were studied. Further, also a lot of models appeared explaining different pre-earthquake phenomena, but unfortunately not all phenomena observed under special conditions. Thus here, various possible earthquake precursors are reviewed. It is discussed how different precursors might be connected. Special attention is payed on contributions by the authors to develop two mechanisms of the generation of electric field variations before earthquakes, to describe non-equilibrium thermodynamic effects, and to explain excitations of plasma turbulence before earthquakes at different altitudes. Also some first active experiments to predict earthquakes are shortly mentioned. It is concluded that only the simultaneous analysis of various earthquake precursors and the simultaneous application of different active methods of prediction using earth-based, atmospheric and satellite methods - but also further-developed 'traditional' seismic methods, will help to solve the earthquake-prediction problem.

  13. 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

  14. Propagating Wave Phenomena Detected in Observations and Simulations of the Lower Solar Atmosphere

    NASA Astrophysics Data System (ADS)

    Jess, D. B.; Shelyag, S.; Mathioudakis, M.; Keys, P. H.; Christian, D. J.; Keenan, F. P.

    2012-02-01

    We present high-cadence observations and simulations of the solar photosphere, obtained using the Rapid Oscillations in the Solar Atmosphere imaging system and the MuRAM magnetohydrodynamic (MHD) code, respectively. Each data set demonstrates a wealth of magnetoacoustic oscillatory behavior, visible as periodic intensity fluctuations with periods in the range 110-600 s. Almost no propagating waves with periods less than 140 s and 110 s are detected in the observational and simulated data sets, respectively. High concentrations of power are found in highly magnetized regions, such as magnetic bright points and intergranular lanes. Radiative diagnostics of the photospheric simulations replicate our observational results, confirming that the current breed of MHD simulations are able to accurately represent the lower solar atmosphere. All observed oscillations are generated as a result of naturally occurring magnetoconvective processes, with no specific input driver present. Using contribution functions extracted from our numerical simulations, we estimate minimum G-band and 4170 Å continuum formation heights of 100 km and 25 km, respectively. Detected magnetoacoustic oscillations exhibit a dominant phase delay of -8° between the G-band and 4170 Å continuum observations, suggesting the presence of upwardly propagating waves. More than 73% of MBPs (73% from observations and 96% from simulations) display upwardly propagating wave phenomena, suggesting the abundant nature of oscillatory behavior detected higher in the solar atmosphere may be traced back to magnetoconvective processes occurring in the upper layers of the Sun's convection zone.

  15. Feedbacks between Hydrological Processes in Tropical South America and Large-Scale Ocean-Atmospheric Phenomena.

    NASA Astrophysics Data System (ADS)

    Poveda, Germn; Mesa, Oscar J.

    1997-10-01

    The hydroclimatology of tropical South America is strongly coupled to low-frequency large-scale oceanicand atmospheric phenomena occurring over the Pacific and the Atlantic Oceans. In particular, El Nio-SouthernOscillation (ENSO) affects climatic and hydrologic conditions on timescales ranging from seasons to decades.With some regional differences in timing and amplitude, tropical South America exhibits negative rainfall andstreamflow anomalies in association with the low-warm phase of the Southern Oscillation (El Nio), and positiveanomalies with the high-cold phase. Such dependence is illustrated in the hydroclimatology of Colombia throughseveral empirical analyses: correlation, empirical orthogonal functions, principal component, and spectral analysis, and discussion of the major physical mechanisms. Observations show that ENSO's effect on river dischargesoccurs progressively later for rivers toward the east in Colombia and northern South America. Also, the impactsof La Nia are more pronounced than those of El Nio. Evidence is also presented to show that processes arisingfrom land-atmosphere interactions in tropical South America affect sea surface temperatures in the Caribbeanand the north tropical Atlantic. A hypothesis is formulated to explain these feedback mechanisms throughperturbations in precipitation, soil moisture, and evapotranspiration over the continent. To begin with, the occurrence of both phases of ENSO affects all those fields. The proposed mechanisms would constitute the `land-atmosphere' bridge connecting Pacific and Atlantic SST anomalies.

  16. Winter weather in Japan controlled by large-scale atmospheric and small-scale oceanic phenomena

    NASA Astrophysics Data System (ADS)

    Ando, Y.; Ogi, M.; Tachibana, Y.; Kodera, K.; Yamazaki, K.

    2014-12-01

    The important components of atmospheric circulation in the winter over the Northern Hemisphere are the Arctic Oscillation (AO) and Western Pacific (WP) pattern. Although in general negative AO and WP phases cause Siberia, East Asia, and Japan to be abnormally cold, Japan was relatively warm in October 2012 even though both the AO and WP were strongly negative. The temperature of the Sea of Japan reached a high in October 2012, and it was found that heating by these very warm waters, despite the small size of the Sea of Japan, overwhelmed the cooling effect of the strongly negative AO and WP in October. Linear regression analyses except the forcing of atmospheric circulations showed that Japan tends to be warm in years when the Sea of Japan is warm. Consequently, the temperature over Japan is statistically controlled by interannual variations of small-scale oceanic phenomena as well as by large-scale atmospheric patterns. Previous studies have ignored such small-scale oceanic influences on island temperatures.

  17. 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.

  18. Luminous Phenomena in the Atmosphere. A New Frontier of New Physics?

    NASA Astrophysics Data System (ADS)

    Teodorani, M.

    1999-03-01

    A main geographic list of anomalous atmospheric light phenomena which are reocurring in several areas of the world is presented. In particular, the Norwegian light-phenomenon occurring in Hessdalen, a prototypical event of this class, is described in great detail. Results obtained in 1984 by the Norwegian scientific organization named 'Project Hessdalen' are discussed. Moreover, the present status and future projects of this organization are presented. It is also shown how the philosophy of research of Project Hessdalen can be adapted to the quantitative investigation of similar light phenomena in other parts of the world. Subsequently, the numerical analysis carried out by the author on the Project Hessdalen 1984 data is shown in detail. After illustrating the several physical theories which have been proposed so far to explain the light phenomenon, a strong emphasis is given on the quantitative definition of instrumental prerequisites and measurable physical parameters. A strategy aimed at defining the investigation methodology and instrumented monitoring in Italian areas of recurrence of the light phenomenon, is presented. An introduction is also given on the documented effects of interaction of the electromagnetic field produced by the light phenomenon with the brain electrical activity of people, by suggesting possible biophysical causes.

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

    NASA Astrophysics Data System (ADS)

    Kokott, Wolfgang

    Lalande's account of his experiences at Gotha and on his journey back to France [AGE 2 (1798), 381-382] contains an interesting attempt to explain the extremely rainy September weather (``at a time of the year when it is raining more rarely in our countries'') by means of the Moon's southern declination. Actually, there are several other documents on the same subject; Lagrange was trying to prove his version of lunar influence against Lamarck who claimed exactly the opposite correlation to be true. In the light of Lalande's own work on oceanic tides, his interest in this meteorological problem is readily understood. While stringent limits for tidal variations of air pressure had already been established by d'Alembert (1747) and Toaldo (1779), no consistent theory of tidal mechanics was yet available. Theoretical and empirical investigations of alleged lunar influences on our weather did remain on the agenda well into the 19th century - the names of Olbers and Arago stand for many contemporaries. Moreover, the Earth's atmosphere was an object of fundamental interest to astronomers not only because of its influence on observational results, but also because it was the only accessible planetary atmosphere. Not only were sizeable gaseous envelopes of planetary bodies (with the apparent exception of only the Moon) considered as commonplace (Herschel, Schröter, etc.); the quest for understanding them was also an importent issue. As early as 1780, J.E. Bode tried (following Euler) to explain the blue colour of the sky by means of blue (scattering?) particles in the upper atmosphere; consequently, he raised the question of whether the red colour of Mars was due to this planet's surface materials or rather to a different atmospheric composition. In our time and age, a new and very successful branch of science called Comparative Planetology did emerge from apparently very modern roots; two centuries ago, its basic objectives were an undisputed part of everyday astronomical 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''.

  20. 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.

  1. HST imaging of atmospheric phenomena created by the impact of comet Shoemaker-Levy 9.

    PubMed

    Hammel, H B; Beebe, R F; Ingersoll, A P; Orton, G S; Mills, J R; Simon, A A; Chodas, P; Clarke, J T; De Jong, E; Dowling, T E

    1995-03-01

    Hubble Space Telescope (HST) images reveal major atmospheric changes created by the collision of comet Shoemaker-Levy 9 with Jupiter. Plumes rose to 3000 kilometers with ejection velocities on the order of 10 kilometers second-1; some plumes were visible in the shadow of Jupiter before rising into sunlight. During some impacts, the incoming bolide may have been detected. Impact times were on average about 8 minutes later than predicted. Atmospheric waves were seen with a wave front speed of 454 +/- 20 meters second-1. The HST images reveal impact site evolution and record the overall change in Jupiter's appearance as a result of the bombardment. PMID:7871425

  2. Transient luminous event phenomena and energetic particles impacting the upper atmosphere: Russian space experiment programs

    NASA Astrophysics Data System (ADS)

    Panasyuk, M. I.; Bogomolov, V. V.; Garipov, G. K.; Grigoryan, O. R.; Denisov, Y. I.; Khrenov, B. A.; Klimov, P. A.; Lazutin, L. L.; Svertilov, S. I.; Vedenkin, N. N.; Yashin, I. V.; Klimov, S. I.; Zeleny, L. M.; Makhmutov, V. S.; Stozkov, Y. I.; Svirzhevsky, N. S.; Klimenko, V. V.; Mareev, E. A.; Shlyugaev, Y. V.; Korepanov, V. E.; Park, I. H.; Salazar, H. I.; Rothkaehl, H.

    2010-06-01

    In Russia several space missions are now planned to study transient luminous events in the atmosphere and high-energy charged particles at satellite altitudes. The experimental goal is to investigate the origin of the high-energy electrons and gamma ray quanta for specific transient luminous events (TLEs) and their role in the ionosphere-magnetosphere system. Simultaneous measurements of electrons at the orbit of the satellite and TLE atmospheric radiation in many wavelength bands will be performed in two missions, Tatiana-2 and RELEC. In the TUS mission UV transient event detection will be accompanied by measurements of the weak UV emission from the seed electrons of extensive air showers of extremely high-primary energies.

  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 comparing two gaseous dry deposition models to determine the fluxes of gaseous elemental mercury and reactive gaseous mercury using the measured concentrations and calculated deposition velocities for each species. Results indicate a large dependence on coupled physical, chemical and biological interactions for atmospheric processes, signifying the need for interdisciplinary collaboration.

  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. Spectral derates phenomena of atmospheric components on multi-junction CPV technologies

    NASA Astrophysics Data System (ADS)

    Armijo, Kenneth M.; Harrison, Richard K.; King, Bruce H.; Martin, Jeffrey B.

    2014-09-01

    The solar spectrum varies with atmospheric conditions and composition, and can have significant impacts on the output power performance of each junction in a concentrating solar photovoltaic (CPV) system, with direct implications on the junction that is current-limiting. The effect of changing solar spectrum on CPV module power production has previously been characterized by various spectral performance parameters such as air mass (AM) for both single and multi-junction module technologies. However, examinations of outdoor test results have shown substantial uncertainty contributions by many of these parameters, including air mass, for the determination of projected power and energy production. Using spectral data obtained from outdoor spectrometers, with a spectral range of 336nm-1715nm, this investigation examines precipitable water (PW), aerosol and dust variability effects on incident spectral irradiance. This work then assesses air mass and other spectral performance parameters, including a new atmospheric component spectral factor (ACSF), to investigate iso-cell, stacked multijunction and single-junction c-Si module performance data directly with measured spectrum. This will then be used with MODTRAN5 to determine if spectral composition can account for daily and seasonal variability of the short-circuit current density Jsc and the maximum output power Pmp values. For precipitable water, current results show good correspondence between the modeled atmospheric component spectral factor and measured data with an average rms error of 0.013, for all three iso-cells tested during clear days over a one week time period. Results also suggest average variations in ACSF factors with respect to increasing precipitable water of 8.2%/cmH2O, 1.3%/cmH2O, 0.2%/cmH2O and 1.8%/cmH2O for GaInP, GaAs, Ge and c-Si cells, respectively at solar noon and an AM value of 1.0. For ozone, the GaInP cell had the greatest sensitivity to increasing ozone levels with an ACSF variation of 0.07%/cmO3. For the desert dust wind study, consistent ACSF behavior between all iso-cells and c-Si was found, with only significant reductions beyond 40mph.

  6. 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.

  7. 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 dividing itself into two light balls where the light-intensity increases and showing a continuous optical spectrum. Later on the light intensity decreases and the continuous optical spectrum is broken up and emission lines appearing, as if the phenomenon goes from a plasma to a gas state. The process ends up when two round light balls are formed, with low optical intensity and red colour, showing sign of a thermal process loosing energy. This observation is to be documented and analyzed.

  8. 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.

  9. 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.

  10. 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)

  11. 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)

  12. 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.

  13. 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.

  14. Rare halos, mirages, anomalous rainbows and related electromagnetic phenomena: A catalog of geophysical anomalies

    NASA Astrophysics Data System (ADS)

    Corliss, W. R.

    Atmospheric optical phenomena are cataloged and evaluated. Topics covered include rainbows and allied spectral phenomena, halo displays and coronas, observer-centered phenomena, low-sun phenomena, mirages, radio and radar anomalies, shadow phenomena, and anomalous geomagnetic disturbances. Also provided are five indexes: time-of-event, place-of-event, first-author, source, and subject.

  15. 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)

  16. Science and Paranormal Phenomena

    SciTech Connect

    Noyes, H. Pierre

    1999-06-03

    In order to ground my approach to the study of paranormal phenomena, I first explain my operational approach to physics, and to the ''historical'' sciences of cosmic, biological, human, social and political evolution. I then indicate why I believe that ''paranormal phenomena'' might-but need not- fit into this framework. I endorse the need for a new theoretical framework for the investigation of this field presented by Etter and Shoup at this meeting. I close with a short discussion of Ted Bastin's contention that paranormal phenomena should be defined as contradicting physics.

  17. Electromagnetic Phenomena in Superconductors

    NASA Astrophysics Data System (ADS)

    Matsushita, Teruo

    Electromagnetic phenomena in superconductors are reviewed. In superconductor in a transverse magnetic field, the electromagnetic phenomena are described by the critical state model assuming a balance between the Lorentz force and pinning force. In this case the Josephson equation for the induced electric field, E = B v, holds for the motion of flux lines with velocity v. On the other hand, the electromagnetic phenomena in a longitudinal magnetic field of current-carrying superconductor are quite different from those in the transverse magnetic field. For example, the Josephson relation does not hold and even a negative potential drop is locally observed in the resistive state above the critical current. In this review it is shown that these peculiar phenomena are explainable using the flux motion driven by a force-free torque, a restoring torque against rotationally shearing deformation of flux lines due to the force-free current parallel to flux lines.

  18. [Hidden electric phenomena].

    PubMed

    Brembilla-Perrot, B

    1995-01-01

    Concealed electrical phenomena are activations which penetrate the specialised tissue incompletely, which do not have a direct electrical effect but which usually affect the conduction of the following normal impulse. The phenomena are extremely common. They arise physiologically in the node of Aschoff Tawara and express the relationship between flutter waves and their propagation to the ventricle. Any extrasystole or ectopic rhythm may give rise to these phenomena and modify conduction in the anterograde or retrograde direction if the ectopic rhythm is ventricular, by slowing the rate but also, in some cases, by paradoxically improving it. In addition, some reciprocating nodal tachycardias are due to a concealed bundle of Kent invisible in sinus rhythm, the presence of which may be suspected by the ECG appearances of the reciprocating tachycardia (negative P wave in lead 1, phenomenon of delaying bundle branch block or simply the auriculogram after the ventriculogram. PMID:7786141

  19. 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).

  20. 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.

  1. 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

  2. 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)

  3. Neutron Star Phenomena

    NASA Technical Reports Server (NTRS)

    Ruderman, Malvin

    1998-01-01

    Various phenomena involving neutron stars are addressed. Electron-positron production in the near magnetosphere of gamma-ray pulsars is discussed along with magnetic field evolution in spun-up and spinning-down pulsars. Glitches and gamma-ray central engines are also discussed.

  4. 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.

  5. Paramutation phenomena in plants.

    PubMed

    Pilu, Roberto

    2015-08-01

    Paramutation is a particular epigenetic phenomenon discovered in Zea mays by Alexander Brink in the 1950s, and then also found in other plants and animals. Brink coined the term paramutation (from the Greek syllable "para" meaning beside, near, beyond, aside) in 1958, with the aim to differentiate paramutation from mutation. The peculiarity of paramutation with respect to other gene silencing phenomena consists in the ability of the silenced allele (named paramutagenic) to silence the other allele (paramutable) present in trans. The newly silenced (paramutated) allele remains stable in the next generations even after segregation from the paramutagenic allele and acquires paramutagenic ability itself. The inheritance behaviour of these epialleles permits a fast diffusion of a particular gene expression level/phenotype in a population even in the absence of other evolutionary influences, thus breaking the Hardy-Weinberg law. As with other gene silencing phenomena such as quelling in the fungus Neurospora crassa, transvection in Drosophila, co-suppression and virus-induced gene silencing (VIGS) described in transgenic plants and RNA interference (RNAi) in the nematode Caenorhabditis elegans, paramutation occurs without changes in the DNA sequence. So far the molecular basis of paramutation remains not fully understood, although many studies point to the involvement of RNA causing changes in DNA methylation and chromatin structure of the silenced genes. In this review I summarize all paramutation phenomena described in plants, focusing on the similarities and differences between them. PMID:26335267

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Hypervelocity impact phenomena

    SciTech Connect

    Chhabildas, L.C.

    1995-07-01

    There is a need to determine the equations of state of materials in regimes of extreme high pressures, temperatures and strain rates that are not attainable on current two-stage light-gas guns. Understanding high-pressure material behavior is crucial to address the physical processes associated with a variety of hypervelocity impact events related to space sciences-orbital-debris impact, debris-shield designs, high-speed plasma propagation, and impact lethality applications. At very high impact velocities material properties will be dominated by phase-changes, such as melting or vaporization, which cannot be achieved at lower impact velocities. Development of well-controlled and repeatable hypervelocity launch capabilities is the first step necessary to improve our understanding of material behavior at extreme pressures and temperatures not currently available using conventional two-stage light-gas gun techniques. In this paper, techniques that have been used to extend both the launch capabilities of a two-stage light gas gun to 16 km/s, and their use to determine the material properties at pressures and temperature states higher than those ever obtained in the laboratory are summarized. The newly developed hypervelocity launcher (HVL) can launch intact (macroscopic dimensions) plates to 16 km/s. Time-resolved interferometric techniques have been used to determine shock-loading/release characteristics of materials impacted by such fliers as well as shock-induced vaporization phenomena in fully vaporized states. High-speed photography or radiography has been used to evaluate the debris propagation characteristics resulting from disc impact of thin bumper sheets at hypervelocities in excess of 10 km/s using the HVL. Examples of these experiments are provided in this paper.

  15. Positron impact ionization phenomena

    NASA Astrophysics Data System (ADS)

    Murtagh, Daniel James

    In the present work, a beam of positrons, obtained from a radioactive source (MNa) in conjunction with a W moderator and guided by a magnetic field, has been used to investigate low energy positron-impact ionization phenomena from atomic and molecular targets. For He below threshold, the investigation discovered vacuum contaminants in creased with gas load and hence concluded that the high 7-ray/ion signal observed by Szluinska and Laricchia (2004a) in Ne could not be safely attributed to annihila tion. A detailed measurement of the total ionization cross-section for He has been performed from below threshold for Ps formation to high energy. Combined with previously measured data and previously measured direct ionization cross-sections (Moxom et al 1996, Ashley et al 1996), a new determination of the positronium formation cross-section has been achieved and compared to other available experi mental measurements and theoretical calculations. Measurements of the excited state (n > 1) positronium formation cross-section for He and Ar have been performed and compared to available theoretical calcu lations. This work has been motivated both for a direct comparison with theory and to test the hypothesis that structure observed in the total (all n) positron ium formation cross-sections for the heavier noble gases, is due to excited state positronium formation (Laricchia et al 2002). The present study is unable to verify fully this hypothesis due to the experimental methods insensitivity to positronium formation in to the 2S or n > 2 states. However, the present results are close to the most sophisticated theoretical calculation of positronium formation into the 2P state (Campbell et al 1998).

  16. Europan surface phenomena

    NASA Astrophysics Data System (ADS)

    Eviatar, A.; Bar-Nun, A.; Podolak, M.

    1985-02-01

    The interaction of corotating iogenic plasma with the surface of Europa in light of recent ice sputtering, experimental results, and published Voyager data has been examined. It has been found that the residual atmosphere of Europa is made up of sputtered molecular oxygen and is exospheric from the surface outwards. It was also found that if sputtering, redistribution, and escape are considered and the sulfur dioxide/water mixing ratio is held constant over a UV observing depth, the observed sulfur dioxide density on the trailing hemisphere lends support to the hypothesis that liquid water from the interior of Europa is boiling out and being deposited as a frost layer on the surface at the rate of about 0.04 ?m/year.

  17. Teaching Optical Phenomena with Tracker

    ERIC Educational Resources Information Center

    Rodrigues, M.; Carvalho, P. Simeo

    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

  18. 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…

  19. Visualizational study on nucleate pool boiling phenomena

    NASA Astrophysics Data System (ADS)

    Kamei, Shuya

    1993-01-01

    It is important to visualize the intricate bubble behavior and the strong agitation of liquid near the heating surface to clarify the details concerning boiling mechanism. The visualization of nucleate pool boiling phenomena was confirmed by means of shadowgraphy using a still- camera (Nikon Photomic Camera) with the speed of 2000 frames per second. Illumination was provided by a photo spotlight or a stroboscope. The photographs show that the boiling phenomena and bubbles' behavior are varied for the heat flux of nucleate pool boiling based on the experiments. By considering the effect of revolving angle and the influence of a space between a tube and a tube, experiments have been carried out to investigate the nucleate pool boiling phenomena on horizontal stainless-steel-multi-tube in saturated distilled water. These experiments were performed for atmospheric pressure, for a stainless-tube diameter of 1.0 mm for a length of 80 mm, for a region of natural convection to nucleate boiling near burnout. From these results, photographs show that the successive motion and shape of bubbles during their process of detachment on the heating tube surface varied with increasing heat flux.

  20. 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.

  1. Teaching optical phenomena with Tracker

    NASA Astrophysics Data System (ADS)

    Rodrigues, M.; Simeo 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, Snells 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.

  2. Attrition and elutriation phenomena in industrial atmospheric fluidized bed combustors

    SciTech Connect

    Wells, J.W.; Krishnan, R.P.

    1980-01-01

    Attrition and elutriation in large-scale AFBC systems depend on the design of the feed system, bed hydrodynamics and freeboard cooling. At present, no generalized correlation exists to predict these effects. It is suggested that routine solid samples for size analysis be taken before the solids enter the bed. In this way, correlations can be developed to predict the attrition in the feed system and in the bed separately. Secondly, data on the solids loading in the freeboard should be taken and related to bubble size, bubble velocity, bubble frequency and bed expansion. Such information can be obtained in a cold bed for lack of measuring techniques in hot beds. Accurate rate expressions for attrition and elutriation specific to coal ash, limestone, and char can then be developed to predict the performance of AFBC systems.

  3. Spectres of short time atmospheric light phenomena:meteors

    NASA Astrophysics Data System (ADS)

    Smirnov, V. A.

    The theory of radiation, the methods of processing (spectrophotometry) and the interpretation of the meteors spectra are given. The original observations as well and the processing of the spectrogrammes is discussed in the connection with influx of various elements to the Earth. The problems of the studiing of the meteoric plasma are outlined. The problems of the meteors explosions are discussed on the basis of the solutions of the kinetic equations. The book is designed for a wide cercle of readers, students and scientists as well. Tables: 14, Illustrations 43; Bibliography: 268

  4. 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

  5. Atmospheric Turbulence and Mesoscale Meteorology

    NASA Astrophysics Data System (ADS)

    Fedorovich, Evgeni; Rotunno, Richard; Stevens, Bjorn

    2004-11-01

    Bringing together leading researchers, this volume surveys recent developments in the fields of atmospheric turbulence and mesoscale meteorology, with particular emphasis on the areas pioneered by Douglas K. Lilly. Numerical simulation is an increasingly important tool for improving our understanding of a wide range of atmospheric phenomena, and this book looks at modern applications.

  6. 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

  7. 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…

  8. Quantum Phenomena Observed Using Electrons

    SciTech Connect

    Tonomura, Akira

    2011-05-06

    Electron phase microscopy based on the Aharonov-Bohm (AB) effect principle has been used to illuminate fundamental phenomena concerning magnetism and superconductivity by visualizing quantitative magnetic lines of force. This paper deals with confirmation experiments on the AB effect, the magnetization process of tiny magnetic heads for perpendicular recording, and vortex behaviors in high-Tc superconductors.

  9. Thermodynamic constraints on fluctuation phenomena

    NASA Astrophysics Data System (ADS)

    Maroney, O. J. E.

    2009-12-01

    The relationships among reversible Carnot cycles, the absence of perpetual motion machines, and the existence of a nondecreasing globally unique entropy function form the starting point of many textbook presentations of the foundations of thermodynamics. However, the thermal fluctuation phenomena associated with statistical mechanics has been argued to restrict the domain of validity of this basis of the second law of thermodynamics. Here we demonstrate that fluctuation phenomena can be incorporated into the traditional presentation, extending rather than restricting the domain of validity of the phenomenologically motivated second law. Consistency conditions lead to constraints upon the possible spectrum of thermal fluctuations. In a special case this uniquely selects the Gibbs canonical distribution and more generally incorporates the Tsallis distributions. No particular model of microscopic dynamics need be assumed.

  10. Thermodynamic constraints on fluctuation phenomena.

    PubMed

    Maroney, O J E

    2009-12-01

    The relationships among reversible Carnot cycles, the absence of perpetual motion machines, and the existence of a nondecreasing globally unique entropy function form the starting point of many textbook presentations of the foundations of thermodynamics. However, the thermal fluctuation phenomena associated with statistical mechanics has been argued to restrict the domain of validity of this basis of the second law of thermodynamics. Here we demonstrate that fluctuation phenomena can be incorporated into the traditional presentation, extending rather than restricting the domain of validity of the phenomenologically motivated second law. Consistency conditions lead to constraints upon the possible spectrum of thermal fluctuations. In a special case this uniquely selects the Gibbs canonical distribution and more generally incorporates the Tsallis distributions. No particular model of microscopic dynamics need be assumed. PMID:20365152

  11. 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.

  12. 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.

  13. 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.

  14. Bubbling phenomena of biharmonic maps

    NASA Astrophysics Data System (ADS)

    Nakauchi, Nobumitsu; Urakawa, Hajime

    2015-12-01

    In this paper, by using Moser's iteration technique, we will show that every sequence in the totality of biharmonic maps between two compact Riemannian manifolds (M, g) and (N, h) with m-energies (m = dim M ? 3) and L2-norm of the tension fields which are bounded above by any positive constant C, causes the bubbling phenomena, which is a generalization of the one for harmonic maps.

  15. Noise Induced Phenomena: a Sampler

    NASA Astrophysics Data System (ADS)

    Wio, Horacio S.; Lindenberg, Katja

    2003-03-01

    Fluctuations or noise have played a changing role in the history of science. Historically, we can identify three views of noise. In the first, up to the end of the 19th century, noise was considered a nuisance to be avoided or eliminated. This is still the implication of the definition of the word noise in any standard dictionary. A second stage dates from the beginning of the 20th century, when it became clear from the study of fluctuations via Onsager relations and fluctuation-dissipation relations that one can obtain useful information about a physical system from its fluctuations. The third stage started about three decades ago, and is marked by the realization that noise can actually play a central role in inducing new phenomena. Examples where noise leads to organized behavior include stochastic resonance, noise-induced phase transitions, noise-induced pattern formation, and noise-induced transport. In this minicourse we sample some such noise-induced phenomena. While many of these fluctuation-induced phenomena involve temporal fluctuations, spatial fluctuations (disorder) can also play a similar organizing role. We briefly illustrate this scenario as well.

  16. 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 according to the standards of the journal. The selection of papers in this issue aims to bring together recent developments and findings, even though it consists of only a fraction of the impressive developments in recent years which have affected a broad range of fields, including the theory of special functions, quantum integrable systems, numerical analysis, cellular automata, representations of quantum groups, symmetries of difference equations, discrete geometry, among others. The special issue begins with four review papers: Integrable models in nonlinear optics and soliton solutions Degasperis [1] reviews integrable models in nonlinear optics. He presents a number of approximate models which are integrable and illustrates the links between the mathematical and applicative aspects of the theory of integrable dynamical systems. In particular he discusses the recent impact of boomeronic-type wave equations on applications arising in the context of the resonant interaction of three waves. Hamiltonian PDEs: deformations, integrability, solutions Dubrovin [2] presents classification results for systems of nonlinear Hamiltonian partial differential equations (PDEs) in one spatial dimension. In particular he uses a perturbative approach to the theory of integrability of these systems and discusses their solutions. He conjectures universality of the critical behaviour for the solutions, where the notion of universality refers to asymptotic independence of the structure of solutions (at the point of gradient catastrophe) from the choice of generic initial data as well as from the choice of a generic PDE. KP solitons in shallow water Kodama [3] presents a survey of recent studies on soliton solutions of the Kadomtsev-Petviashvili (KP) equation. A large variety of exact soliton solutions of the KP equation are presented and classified. The study includes numerical analysis of the stability of the found solution as well as numerical simulations of the initial value problems which indicate that a certain class of initial waves approach asymptotically these exact solutions of the KP equation. The author discusses an application of the theory to the problem of the resonant interaction of solitary waves appearing in the reflection of an obliquely incident wave onto a vertical wall, known as the Mach reflection problem in shallow water. A beautiful explanation of the problem was presented in a swimming pool experiment during NEEDS 2009. Smooth and peaked solitons of the CH equation Holm and Ivanov [4] discuss the relations between smooth and peaked soliton solutions for the Camassa-Holm (CH) shallow water wave equation in one spatial dimension. They first present the derivation of the soliton solution for the CH equation by means of inverse scattering transform (IST); the solution is obtained in a form that admits the peakon limit. The canonical Hamiltonian formulation of the CH equation in action-angle variables is recovered using the scattering data. The authors review some of the geometric properties of the CH equation and conclude their review with the higher dimensional generalization of the dispersionless CH equation, known as EPDiff. They also consider the possible extensions of their approach in three open problems. Regular contributions to this issue cover a wide range of topics related to integrable systems. Let us briefly illustrate some of the topics covered by this issue. One of the main topics is the study of hierarchies of integrable equations. The multifaceted idea of integrability of a particular PDE includes an approach whose aim is to find an infinite set of independent conserved quantities, much in the spirit of Liouville integrability in classical mechanics. The existence of these conserved quantities in involution, or of the corresponding infinite set of commuting symmetries, leads to an infinite set of commuting flows; i.e., to the construction of a hierarchy of compatible PDEs with respect to an infinite set of times. Obviously one can generalize or adapt this construction to different settings like the integro-differential, discrete or super-symmetric ones. The emphasis is usually to find auxiliary linear systems defining an infinite set of linear commuting flows whose solutions, if some asymptotic conditions are imposed, are named wave or Baker-Akhiezer functions. These linear flows determine the so called Lax equations, another infinite set of commuting equations whose compatibility leads to the so called Zakharov-Shabat system. An alternative description of the hierarchies is achieved with the use of the bilinear equations directly linked with the tau-function description of the hierarchy. There are two paradigmatic integrable hierarchies, namely the KP and 2-dimensional Toda lattice (2DTL). These hierarchies are treated within this volume in three contributions. In particular, Takasaki [5] reconsiders the extended Toda hierarchy of Carlet, Dubrovin and Zhang in the light of Ogawa's 2 + 1D extension of the 1D Toda hierarchy. It turns out that the former may be thought of as some sort of dimensional reduction of the latter. This explains the structure of the bilinear formalism proposed by Milanov. Carlet and Manas [6] study the 2-component KP and 2D Toda hierarchies and solve explicitly several implicit constraints present in the usual Lax formulation of the hierarchy, thus identifying a set of free dependent variables for such hierarchies. Finally, the KP hierarchy is considered in the paper by Lin et al [7], which explores the extended flows of a q-deformed modified KP hierarchy leading to the introduction of self-consistent sources. By a combination of the dressing method and the method of variation of constants, the authors are able through a dressing approach to find a scheme for the construction of solutions of the corresponding integrable equations with self-consistent sources. The study of dispersionless integrable hierarchies is an active field of research, and this special issue includes two papers devoted to the subject. Konopelchenko et al [8] describe critical and degenerate critical points of a scalar function which obeys the Euler-Poisson-Darboux equation in terms of the hodograph solutions of the dispersionless coupled Korteweg-de Vries hierarchies. Finally, Bogdanov [9] considers 2-component integrable generalizations of the dispersionless 2D Toda lattice hierarchy connected with non-Hamiltonian vector fields, similar to the Manakov-Santini hierarchy generalizing the dKP hierarchy. He presents the simplest 2-component generalization of the dispersionless 2DTL equation, being its differential reduction analogous to the Dunajski interpolating system. Some papers in the issue are concerned with methods to construct solutions of integrable systems, while others place more emphasis on studying properties of specific solutions of applicative interest. Among the first approach, the paper by Kaup and van Gorder [10] describes perturbation theory applied to the Inverse Scattering Transform in 3x eigenvalue problems of Zakharov-Shabat's type. Schiebold [11] studies a projection method to construct solutions of the Ablowitz-Kaup-Newell-Segur (AKNS) system, which enables her to write explicit N-soliton solutions in closed form. An example of the second kind is the paper by Biondini and Wang [12], who study in detail the behaviour of line soliton solutions of the 2DTL, describing their directions and amplitudes and also the richness of their interactions, which include resonant soliton interactions and web structure. An important field of study in integrable systems relates to the singularity structure of the solutions to nonlinear equations. When all movable singularities are poles, the system is said to have the Painleve property. The solutions may be multivalued but they can be analytically continued to meromorphic functions on the universal cover of the punctured Riemann sphere (the punctures being the fixed singularities) and the spectral curve is an affine algebraic curve. Benes and Previato [13] study the connection between the Painleve property and algebras of differential operators, extending an approach initiated by Flaschka. Solutions to some integrable systems can be constructed in terms of analytic objects associated to a spectral algebraic curve. It is therefore of interest to study the Riemann surfaces of algebraic functions, a program illustrated in the paper by Braden and Northover [14], who have implemented some algorithms for this purpose in a popular symbolic computation software. In the paper by Zhilinski [15], the critical points of the energy momentum map in classical Hamiltonian problems with nontrivial monodromy are shown to form regular lattices. The quantum mechanical counterpart has similar lattices for the joint spectrum of the commuting observables. Some examples are given in which these points form special geometric patterns. Claeys [16] uses analytic techniques and Riemann-Hilbert problems to study the asymptotic behaviour when x and t tend to infinity of a solution to the second member of the Painleve I hierarchy, which arises in multicritical string model theory and random matrix theory. This solution is conjectured to describe the universal asymptotics for Hamiltonian perturbations of hyperbolic equations near the point of gradient catastrophe for the unperturbed equation. Darboux and Backlund transformations were born more than a century ago in the context of the geometric theory of surfaces. In the past few decades they have become a useful element in the theory of integrability, with applications in different guises. Typically, they appear in dressing methods that show how to construct new interesting solutions from known simple ones. A few of the contributed papers to the issue make use of these transformations as one of their fundamental objects. Liu et al [17] use iterated Darboux transformations to construct compact representations of the multi-soliton solutions to the derivative nonlinear Schroedinger (DNLS) equation. Ragnisco and Zullo [18] construct Backlund transformations for the trigonometric classical Gaudin magnet in the partially anisotropic (xxz) case, identifying the subcase of transformations that preserve the real character of the variables. The recently discovered exceptional polynomials are complete polynomial systems that satisfy Sturm-Liouville problems but differ from the classical families of Hermite, Laguerre and Jacobi. Gomez-Ullate et al [19] prove that the families of exceptional orthogonal polynomials known to date can be obtained from the classical ones via a Darboux transformation, which becomes a useful tool to derive some of their properties. Integrability in the context of classical mechanics is associated to the existence of a sufficient number of conserved quantities, which allows sometimes an explicit integration of the equations of motion. This is the case for the motion of the Chaplygin sleigh, a rigid body motion on a fluid with nonholonomic constraints studied in the paper by Fedorov and Garcia-Naranjo [20], who derive explicit solutions and study their asymptotic behaviour. In connection with classical mechanics, some techniques of KAM theory have been used by Procesi [21] to derive normal forms for the NLS equation in its Hamiltonian formulation and prove existence and stability of quasi-periodic solutions in the case of periodic boundary conditions. Algebraic and group theoretic aspects of integrability are covered in a number of papers in the issue. The quest for symmetries of a system of differential equations usually allows us to reduce the order or the number of equations or to find special solutions possesing that symmetry, but algebraic aspects of integrable systems encompass a wide and rich spectrum of techniques, as evidenced by the following contributions. Muriel and Romero [22] perform a systematic study of all second order nonlinear ODEs that are linearizable by generalized Sundman and point transformations, showing that the two classes are inequivalent and providing an explicit characterization thereof. Lie algebras are also prominent in the work of Gerdjikov et al [23], where a class of integrable PDEs associated to symmetric spaces is studied in detail. In their approach, systems of nonlinear integrable PDEs are obtained as reductions of generic integrable systems corresponding to Lax operators with matrix coefficients. The reduction here is carried out using a reduction group which reflects symmetries of the Lax operator. These symmetries allow also a characterization of the corresponding Riemann-Hilbert data. Habibullin [24] employs algebraic techniques to study discrete chains of differential-difference equations that are Darboux integrable, i.e. that admit a certain number of nontrivial first integrals. Musso [25] provides a unified algebraic framework for the rational, trigonometric and elliptic Gaudin models. The results are achieved using a generalization of the Gaudin algebras and of the so-called coproduct method. Odesskii and Sokolov [26] present a classification of all infinite (1+1)-dimensional hydrodynamic-type chains of shift one. They establish a one-to-one correspondence between integrable chains and infinite triangular Gibbons-Tsarev (GT) systems and thus reduce the classification problem to a description of all GT-systems. In Korff's paper [27] we find a study of various algebraic and combinatorial structures that emerge in the statistical vertex model with infinite spin, an integrable model associated to a certain quantum affine algebra. In the crystal limit, this model is connected with the WZNW model in conformal field theory. The motivation for some of the submitted contributions arises also from field theories in theoretical physics. Ferreira et al [28] construct soliton solutions with non-zero topological charges to the Skyrme-Faddeev model in Yang-Mills theory. Using techniques of differential geometry and complex analysis, Manton and Rink [29] explore vortex solutions on hyperbolic surfaces extending an approach by Witten. These solutions can be interpreted as self-dual SU(2) Yang-Mills fields on R4. Shah and Woodhouse [30] use the Penrose-Ward correspondence from twistor theory to relate generalized anti self-duality equations to certain isomonodromic problems whose solutions are expressed in terms of generalized hypergeometric functions. Applications of integrable systems and nonlinear phenomena in other fields are also present in some of the papers. Kanna et al [31] study the collision of soliton solutions to coherently coupled NLS equations using a variant of the Hirota bilinearization method. Their results have applications in pulse shaping in nonlinear optics. Calogero et al [32] present examples of systems of ODEs with quadratic nonlinearities that could describe rate equations in chemical dynamics. They derive explicit conditions on the parameters of the problem for which the solutions are periodic and isochronous. Ablowitz and Haut [33] study the motion of large amplitude water waves with surface tension using asymptotic expansions and providing a comparison with experimental results. This issue is the result of the collaboration of many individuals. We would like to thank the editors and staff of the Journal of Physics A: Mathematical and Theoretical for their enthusiastic support and efficient help during the preparation of this issue. A key factor has been the work of many anonymous referees who performed careful analysis and scrutiny of the research papers submitted to this issue, often making remarks which helped to improve their quality and readability. They carried out dedicated, altruistic work with a very high standard and this issue would not exist without their contribution. Finally, we would like to thank the authors who responded to our open call, sending us their most recent results and sharing with us the enthusiasm and interest for this fascinating field of research. We hope that this collection of papers will provide a good overview for anyone interested in recent developments in the field of integrability and nonlinear phenomena. [1] Integrable models in nonlinear optics and soliton solutions Degasperis A [2] Hamiltonian PDEs: deformations, integrability, solutions Dubrovin B [3] Smooth and peaked solitons of the CH equation Holm D D and Ivanov R I [4] KP solitons in shallow water Kodama Y [5] Two extensions of 1D Toda hierarchy Takasaki K [6] On the Lax representation of the 2-component KP and 2D Toda hierarchies Guido Carlet and Manuel Manas [7] The q-deformed mKP hierarchy with self-consistent sources, Wronskian solutions and solitons Lin R L, Peng H and Manas M [8] Hodograph solutions of the dispersionless coupled KdV hierarchies, critical points and the Euler-Poisson-Darboux equation Konopelchenko B, Martinez Alonso L and E Medina [9] Non-Hamiltonian generalizations of the dispersionless 2DTL hierarchy Bogdanov L V [10] Squared eigenfunctions and the perturbation theory for the nondegenerate N x N operator: a general outline Kaup D J and Van Gorder R A [11] The noncommutative AKNS system: projection to matrix systems, countable superposition and soliton-like solutions Schiebold C [12] On the soliton solutions of the two-dimensional Toda lattice Biondini G and Wang D [13] Differential algebra of the Painleve property Benes G N and Previato E [14] Klein's curve Braden H W and Northover T P [15] Quantum monodromy and pattern formation Zhilinskii B [16] A symptotics for a special solution to the second member of the Painleve I hierarchy Claeys T [17] Darboux transformation for a two-component derivative nonlinear Schroedinger equation Ling L and Liu Q P [18] Backlund transformations as exact integrable time discretizations for the trigonometric Gaudin model Ragnisco O and Zullo F [19] Exceptional orthogonal polynomials and the Darboux transformation Gomez-Ullate D, Kamran N and Milson R [20] The hydrodynamic Chaplygin sleigh Fedorov Y N and Garcia-Naranjo L C [21] A normal form for beam and non-local nonlinear Schroedinger equations Procesi M [22] Nonlocal transformations and linearization of second-order ordinary differential equations Muriel and Romero J L [23] Reductions of integrable equations on A.III-type symmetric spaces Gerdjikov V S, Mikhailov A V and Valchev T I [24] On Darboux-integrable semi-discrete chains Habibullin I, Zheltukhina N and Sakieva A [25] Loop coproducts, Gaudin models and Poisson coalgebras Musso F [26] Classification of integrable hydrodynamic chains Odesskii A V and Sokolov V V [27] Noncommutative Schur polynomials and the crystal limit of the Uq sl(2)-vertex model Korff C [28] Axially symmetric soliton solutions in a Skyrme-Faddeev-type model with Gies's extension Ferreira L A, Sawado N and Toda K [29] Vortices on hyperbolic surfaces Manton N S and Rink N A [30] Multivariate hypergeometric cascades, isomonodromy problems and Ward ansatze Shah M R and Woodhouse N J M [31] Coherently coupled bright optical solitons and their collisions Kanna T, Vijayajayanthi M and Lakshmanan M [32] Isochronous rate equations describing chemical reactions Calogero F, Leyvraz F and Sommacal M [33] Asymptotic expansions for solitary gravity-capillary waves in two and three dimensions Ablowitz M J and Haut T S

  17. 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.

  18. 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

  19. 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)

  20. 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.

  1. Earth, atmosphere

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.

    1991-01-01

    Present understanding of the earth's atmosphere is briefly reviewed. The structure and composition of the atmosphere are described. The origin of the atmosphere and the factors involved in global atmospheric change are addressed.

  2. 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.

  3. 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

  4. 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.

  5. 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).

  6. 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.

  7. 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.

  8. 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 ?4 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.

  9. Onset phenomena in MPD thrusters

    NASA Technical Reports Server (NTRS)

    Barnett, J. W.; Jahn, R. G.

    1985-01-01

    An experimental study has clarified some aspects of MPD thruster onset phenomena. The steep increase in terminal voltage that occurs as the onset current is approached may have different causes, depending on the propellant injection geometry. For propellant injection at the cathode radius, terminal voltage increase corresponds to a growing anode fall voltage; for injection at a larger radius, the increase is related to the back emf in the near-cathode plasma. The formation of the onset current pattern within the arc has been mapped experimentally as the thruster responds to an input current step which rises from below onset to the onset value. The appearance of terminal voltage hash at onset correlates with the extension into the exhaust region of a significant fraction of the arc current.

  10. The quest for new phenomena

    SciTech Connect

    Hinchliffe, I.

    1996-12-01

    The Standard Model of particle physics has been very successful in describing experimental data with great precision. With the exception of some neutrino anomalies, there is no data that is in disagreement with it. Nevertheless, the model is regarded as incomplete and unsatisfactory. There is no explanation of the pattern of quark and lepton masses and, possibly more important, no understanding of the scale of electroweak interactions. Electroweak symmetry breaking is implemented in the Standard Model from the presence of a scalar electroweak doublet, the Higgs field, that acquires a vacuum expectation value of order 250 GeV and leaves as a remnant one physical state, the electrically neutral Higgs boson whose mass is not predicted. In this talk, the author compares the techniques used at, and capabilities of, various facilities in searching for new phenomena. The author emphasizes the cases where information from more than one facility may be needed to fully explore the physics.

  11. Weak values as interference phenomena

    NASA Astrophysics Data System (ADS)

    Dressel, Justin

    2015-03-01

    Weak values arise experimentally as conditioned averages of weak (noisy) observable measurements that minimally disturb an initial quantum state, and also as dynamical variables for reduced quantum state evolution even in the absence of measurement. These averages can exceed the eigenvalue range of the observable ostensibly being estimated, which has prompted considerable debate regarding their interpretation. Classical conditioned averages of noisy signals only show such anomalies if the quantity being measured is also disturbed prior to conditioning. This fact has recently been rediscovered, along with the question whether anomalous weak values are merely classical disturbance effects. Here we carefully review the role of the weak value as both a conditioned observable estimation and a dynamical variable, and clarify why classical disturbance models will be insufficient to explain the weak value unless they can also simulate other quantum interference phenomena.

  12. 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 operator changes sign with T-operation. (iii) Gauge symmetry (G), which is associated with a change in the phase of the wave-function as {Psi} {yields} e{sup i{theta}}{Psi}. Gauge symmetry is connected to the law of charge conservation, and broken G-symmetry corresponds to superconductivity/superfluidity. To summarize, the interplay among these electronic degrees of freedom produces various forms of symmetry breaking patterns of I, T, and G, leading to novel emergent phenomena, which can appear only by the collective behavior of electrons and cannot be expected from individual electrons. Figure 1 shows this schematically by means of several representative phenomena. From this viewpoint, the interfaces of TMOs offer a unique and important laboratory because I is already broken by the structure itself, and the detailed form of broken I-symmetry can often be designed. Also, two-dimensionality usually enhances the effects of electron correlations by reducing their kinetic energy. These two features of oxide interfaces produce many novel effects and functions that cannot be attained in bulk form. Given that the electromagnetic responses are a major source of the physical properties of solids, and new gauge structures often appear in correlated electronic systems, we put 'emergent electromagnetism' at the center of Fig. 1.

  13. 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.

  14. 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.

  15. 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.

  16. 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 measurements and calculations of the bulk electromechanical coefficients remain challenging. Much of the literature has focused on InGaN/GaN, AlGaN/GaN, ZnMgO/ZnO, and ZnCdO/ZnO quantum wells, and InAs/GaAs and AlGaN/AlN quantum dots for their optoelectronic properties; and work on the bending of nanowires have been mostly for GaN and ZnO nanowires. We hope the present review article will stimulate further research into the field of electromechanical phenomena and help in the development of applications.

  17. 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.

  18. 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 of quantum cellular automata, a new paradigm for computing as reported by Craig S Lent and colleagues (Lent C S, Tougaw P D, Porod W and Bernstein G H 1993 Nanotechnology 4 49-57). The increasingly sophisticated manipulation of spin has been an enduring theme of research throughout this decade, providing a number of interesting developments such as spin pumping (Cota E, Aguado R, Creffield C E and Platero G 2003 Nanotechnology 14 152-6). The idea of spin qubits, proposed by D Loss and D P DiVincenzo (1998 Phys. Rev. A 57 120), developed into an established option for advancing research in quantum computing and continues to drive fruitful avenues of research, such as the integrated superconductive magnetic nanosensor recently devised by researchers in Italy (Granata C, Esposito E, Vettoliere A, Petti L and Russo M 2008 Nanotechnology 19 275501). The device has a spin sensitivity in units of the Bohr magneton of 100 spin Hz-1/2 and has large potential for applications in the measurement of nanoscale magnetization and quantum computing. The advance of science and technology at the nanoscale is inextricably enmeshed with advances in our understanding of quantum effects. As Nanotechnology celebrates its 20th volume, research into fundamental quantum phenomena continues to be an active field of research, providing fertile pasture for developing nanotechnologies.

  19. Understanding empathy and related phenomena.

    PubMed

    Shamasundar, C

    1999-01-01

    Over a period of time, the author arrived at a few tentative postulates concerning empathy and related processes based on some of his experiences and observations. The central theme of these postulates is, firstly, that interpersonal interaction is an interaction of the personal-space fields. Secondly, empathy, therapeutic benefit, and the professional stress are all related to the same process of interpersonal interaction. This interaction takes place as an enmeshment of personal spaces of the interacting individuals, and involves transfer of a wide range of information in the affective, cognitive, and other areas. This is because the personal spaces have fieldlike qualities analogous to what Kurt Lewin described. Thus, such phenomena as empathy, therapeutic benefit, professional stress are all consequences of the same process. It is possible to substantiate these postulates by diverse evidences in the published literature. The natural consequences of such an interpersonal interaction are empathic understanding, transfer of mood states (like hope, distress or expectancy), affective states (like anxiety, sadness, anger or hostility), ideas, images and even attitudes and values, etc. This phenomenon of transfer can explain such processes as therapeutic benefit in individual and group settings, professional stress, shared delusions, and even experimenter bias. Whether one becomes aware of such transferred information or not depends upon the intent and sensitivity of the participants. PMID:10415993

  20. Conductance phenomena in microcrystalline cellulose

    NASA Astrophysics Data System (ADS)

    Nilsson, M.

    2006-02-01

    We have investigated the conduction phenomena in compacted tablets of cellulose with varying relative humidity (RH) with techniques such as Low Frequency Dielectric Spectroscopy (LFDS) and Transient Current (TC) at room temperature. Two exponential decaying regions in the transient current measurements indicate two ionic species contributing to the conduction mechanism. A high power-law exponent of 9 for the conductance with moisture content has been found. The mobility initially decreases with RH up to monolayer coverage, and further water vapor increases the mobility, indicating a blocking of available positions for the charge carrier ions. When the amount of water molecules present in the tablet increases one order of magnitude, the number of charge carriers increases 5-6 orders of magnitude, suggesting a transition from a power-law increase to a linear effective medium theory for the conduction. The charge carrier dependence on RH suggests that a percolating network of water molecules adsorbed to 6-OH units on the cellulose chain span through the sample. The conductivity mechanisms in cellulose are still not clear.

  1. Critical Phenomena in Population Coding

    NASA Astrophysics Data System (ADS)

    Berkowitz, John; Sharpee, Tatyana

    2014-03-01

    Populations of neurons that code for sensory stimuli are often modeled as having sigmoidal tuning curves where the midpoint and slope of the curve represent, respectively, an intrinsic firing threshold and noise level. Recent studies have shown for two subpopulations of neurons that states below a critical noise level are associated with symmetry breaking between the populations' thresholds. In this work we consider the case of up to seven distinct subpopulations encoding a common gaussian stimulus. We optimized the mutual information between output patterns and stimuli by adjusting the thresholds for a fixed noise level. In the high-noise regime the optimal thresholds are fully redundant whereas the low noise limit predicts distinct threshold values that achieve histogram equalization of the input signal. Between the two limits, the thresholds exhibit a complex branching process that occur at successive values of the noise level. Each branch corresponds to a critical point of a continuous phase transition. The behavior of the system in the limit of a large number of subpopulations is also investigated, and critical phenomena are also present in the distribution of thresholds in this limit.

  2. 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.

  3. Atmospheric electrification

    NASA Technical Reports Server (NTRS)

    Kasemir, H. W.

    1978-01-01

    Research areas of atmospheric electricity that could be explored from the shuttle or the tethered satellite are discussed. Emphasis is placed on atmospheric current flow and telluric currents. A model depicting the atmospheric electric global circuit is presented.

  4. 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.

  5. Galvanomagnetic phenomena in layered organic conductors (Review)

    NASA Astrophysics Data System (ADS)

    Kartson?k, M. V.; Peschansky, V. G.

    2005-03-01

    The experimental research on galvanomagnetic phenomena in layered organic conductors at high magnetic fields is discussed in terms of the theoretical ideas about charge transfer phenomena in conductors with a metallic type of conductivity and a quasi-two-dimensional electron energy spectrum of arbitrary form. Attention is devoted mainly to the problem of recovering the dispersion relation of the conduction electrons in layered organic charge-transfer complexes from experimental studies of their magnetoresistance and quantum oscillation phenomena at low temperatures.

  6. 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.

  7. Jump phenomena. [large amplitude responses of nonlinear systems

    NASA Technical Reports Server (NTRS)

    Reiss, E. L.

    1980-01-01

    The paper considers jump phenomena composed of large amplitude responses of nonlinear systems caused by small amplitude disturbances. Physical problems where large jumps in the solution amplitude are important features of the response are described, including snap buckling of elastic shells, chemical reactions leading to combustion and explosion, and long-term climatic changes of the earth's atmosphere. A new method of rational functions was then developed which consists of representing the solutions of the jump problems as rational functions of the small disturbance parameter; this method can solve jump problems explicitly.

  8. 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.

  9. 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.

  10. 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.

  11. Understanding of thermoacoustic phenomena and their applications

    NASA Astrophysics Data System (ADS)

    Biwa, Tetsushi

    2012-09-01

    The problem of acoustic wave propagation in a tube provides a starting point for the study of thermoacoustic phenomena, which can be analyzed in detail using hydrodynamics. A thermodynamic approach has elucidated various applications of thermoacoustic phenomena. The thermoacoustical perspective unifies these two approaches through acoustical energy flows and facilitates the development of thermoacoustic heat engines.

  12. Atmospheric effects on oblique impacts

    NASA Technical Reports Server (NTRS)

    Schultz, P. H.

    1991-01-01

    Laboratory experiments and theoretical calculations often use vertical impact angles (90 deg) in order to avoid the complicating effect of asymmetry. Nevertheless, oblique impacts represent the most likely starting condition for planetary cratering. Changing both impact angles and atmospheric pressure not only allows testing previous results for vertical impacts but also reveals phenomena whose signatures would otherwise be masked in the planetary cratering record. The laboratory studies were performed for investigating impact cratering processes. Impact angles can be increased from 0 to 90 deg in 15 deg increments while maintaining a flat target surface. Different atmospheres (nitrogen, argon, and helium) characterized the effects of both gas density and Mach number. Targets varied according to purpose. Because of the complexities in atmosphere-impactor-ejecta interactions, no single combination allows direct simulation of a planetary-scale (10-100 km) event. Nevertheless, fundamental processes and observed phenomena allow formulating first-order models at such broad scales.

  13. Understanding the Physics of changing mass phenomena

    NASA Astrophysics Data System (ADS)

    Ellermeijer, A. L.

    2008-05-01

    Changing mass phenomena, like a falling chain or a bungee jumper, might give surprising results, even for experienced physicists. They have resulted in hot discussions in journals, in which for instance Physics professors claim the impossibility of an acceleration larger then g in case of a bungee jumper. These phenomena are also interesting as topics for challenging student projects, and used as such by Dutch high school students. I will take these phenomena as the context in which I like to demonstrate the possibilities of ICT in the learning process of physics. Especially dynamical modeling enables us to describe these phenomena in an elegant way and with knowledge of high school mathematics. Furthermore tools for video-analysis and data from measurements with sensors allow us to study the phenomena in experiments. This example demonstrates the level of implementation of ICT in Physics Education in The Netherlands [1].

  14. 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.

  15. The Seismoacoustic Wavefield: A New Paradigm in Studying Geophysical Phenomena

    NASA Astrophysics Data System (ADS)

    Arrowsmith, Stephen J.; Johnson, Jeffrey B.; Drob, Douglas P.; Hedlin, Michael A. H.

    2010-12-01

    The field of seismoacoustics is emerging as an important discipline in its own right, owing to the value of colocated seismic and infrasound arrays that sample elastic energy propagating in both the solid Earth and the atmosphere. The fusion of seismic and infrasonic data provides unique constraints for studying a broad range of topics including the source physics of natural and man-made events, interaction of mechanical waves in Earth's crust and atmosphere, source location and characterization, and inversion of atmospheric and shallow subsurface properties. This review article traces the seismoacoustic wavefield from source to receiver. Beginning at the source, we review the latest insights into the physics of natural and anthropogenic sources that have arisen from the analysis of seismoacoustic data. Next, a comparative review of 3-D models of the atmosphere and solid Earth and the latest algorithms for modeling the propagation of mechanical waves through these media provides the framework for a discussion of the seismoacoustic path. The optimal measurement of seismic and acoustic waves, including a discussion of instrumentation, as well as of array configurations and regional networks, is then outlined. Finally, we focus on broad research applications where the analysis of seismoacoustic data is starting to yield important new results, such as in the field of nuclear explosion monitoring. This review is intended to provide a primer on the field of seismoacoustics for seismologists or acousticians, while also providing a more general review of what constraints seismoacoustics can uniquely provide for understanding geophysical phenomena.

  16. Electromagnetic charges in aggregation phenomena.

    NASA Astrophysics Data System (ADS)

    Rioux, Claude; Slobodrian, R. J.

    Introduction The mechanism of fine particles aggregation is of great importance in many areas of research, in particular environment sciences where the state of aggregation defines the removal speed of dust from the atmosphere. The study of this mechanism is also important to understand the first stage of planet formation from the solar nebula. The aggregates formed are generally fractals and, as mentioned in the literature [1], the fractal dimensions and the site growth probability measures of the resulting fractal structures strongly depend on the properties of the forces that cause the aggregation. Theory and experimental apparatus We began this study by the aggregation between two charged particles and we are now consid-ering the aggregation between two magnetized particles. The aggregations are produced in a gas at a pressure between 10 and 1000 mbar and by using the applicable simplifications; we find that the distance (r) between the particles as a function of time (t) is given by the following equations: r=Ce(tf -t)1/3 for the electrical attraction r=Cm(tf -t)1/5 for the magnetic dipoles aligned in an external magnetic field. The apparatus built for these measurements consists of an experimental cell from which two perpendicular views are combined via an optical system in one image recorded by a video camera. From the video, we can then measure the distance between the particles as a function of time and reconstruct the trajectories in 3-D. The horizontal and vertical resolutions are respectively 0.86 and 0.92 microns per pixel. With a depth of field of 250 microns, the usable volume for 3-D observation in then 250 microns x 250 microns x 443 microns. Results and discussion A first version of the apparatus was tested on an electrical force aggregation and the results [2] show that the corresponding equation is a good representation of the phenomenon. Preliminary results, from an experiment using iron particles, show that the magnetic force can be seen in the aggregations. From these results, we believe that we can discriminate between the two forces and knowing the constants, it will be possible to obtain the product of the charges (or of the magnetic moments) without disturbing the aggregation process. This will result in a powerful diagnostic instrument to further the study of the fine powder aggregation mechanism. [1] A. Block, W. von Bloh and H.J. Schellnhuber, J. Phys. A 24, L1037 (1991). [2] C. Rioux, L. Potvin and R.J. Slobodrian, Phys. Rev. E, vol. 52, p. 2099 (1995).

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. Atmosphere-Ionosphere Electrodynamic Coupling

    NASA Astrophysics Data System (ADS)

    Sorokin, V. M.; Chmyrev, V. M.

    Numerous phenomena that occur in the mesosphere, ionosphere, and the magnetosphere of the Earth are caused by the sources located in the lower atmosphere and on the ground. We describe the effects produced by lightning activity and by ground-based transmitters operated in high frequency (HF) and very low frequency (VLF) ranges. Among these phenomena are the ionosphere heating and the formation of plasma density inhomogeneities, the excitation of gamma ray bursts and atmospheric emissions in different spectral bands, the generation of ULF/ELF/VLF electromagnetic waves and plasma turbulence in the ionosphere, the stimulation of radiation belt electron precipitations and the acceleration of ions in the upper ionosphere. The most interesting results of experimental and theoretical studies of these phenomena are discussed below. The ionosphere is subject to the action of the conductive electric current flowing in the atmosphere-ionosphere circuit. We present a physical model of DC electric field and current formation in this circuit. The key element of this model is an external current, which is formed with the occurrence of convective upward transport of charged aerosols and their gravitational sedimentation in the atmosphere. An increase in the level of atmospheric radioactivity results in the appearance of additional ionization and change of electrical conductivity. Variation of conductivity and external current in the lower atmosphere leads to perturbation of the electric current flowing in the global atmosphere-ionosphere circuit and to the associated DC electric field perturbation both on the Earth's surface and in the ionosphere. Description of these processes and some results of the electric field and current calculations are presented below. The seismic-induced electric field perturbations produce noticeable effects in the ionosphere by generating the electromagnetic field and plasma disturbances. We describe the generation mechanisms of such experimentally observed effects as excitation of plasma density inhomogeneities, field-aligned currents, and ULF/ELF emissions and the modification of electron and ion altitude profiles in the upper ionosphere. The electrodynamic model of the ionosphere modification under the influence of some natural and man-made processes in the atmosphere is also discussed. The model is based on the satellite and ground measurements of electromagnetic field and plasma perturbations and on the data on atmospheric radioactivity and soil gas injection into the atmosphere.

  10. Self field electromagnetism and quantum phenomena

    NASA Astrophysics Data System (ADS)

    Schatten, Kenneth H.

    1994-07-01

    Quantum Electrodynamics (QED) has been extremely successful inits predictive capability for atomic phenomena. Thus the greatest hope for any alternative view is solely to mimic the predictive capability of quantum mechanics (QM), and perhaps its usefulness will lie in gaining a better understanding of microscopic phenomena. Many ?paradoxes? and problematic situations emerge in QED. To combat the QED problems, the field of Stochastics Electrodynamics (SE) emerged, wherein a random ?zero point radiation? is assumed to fill all of space in an attmept to explain quantum phenomena, without some of the paradoxical concerns. SE, however, has greater failings. One is that the electromagnetic field energy must be infinit eto work. We have examined a deterministic side branch of SE, ?self field? electrodynamics, which may overcome the probelms of SE. Self field electrodynamics (SFE) utilizes the chaotic nature of electromagnetic emissions, as charges lose energy near atomic dimensions, to try to understand and mimic quantum phenomena. These fields and charges can ?interact with themselves? in a non-linear fashion, and may thereby explain many quantum phenomena from a semi-classical viewpoint. Referred to as self fields, they have gone by other names in the literature: ?evanesccent radiation?, ?virtual photons?, and ?vacuum fluctuations?. Using self fields, we discuss the uncertainty principles, the Casimir effects, and the black-body radiation spectrum, diffraction and interference effects, Schrodinger's equation, Planck's constant, and the nature of the electron and how they might be understood in the present framework. No new theory could ever replace QED. The self field view (if correct) would, at best, only serve to provide some understanding of the processes by which strange quantum phenomena occur at the atomic level. We discuss possible areas where experiments might be employed to test SFE, and areas where future work may lie.

  11. 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.

  12. A new asymptotic method for jump phenomena

    NASA Technical Reports Server (NTRS)

    Reiss, E. L.

    1980-01-01

    Physical phenomena involving rapid and sudden transitions, such as snap buckling of elastic shells, explosions, and earthquakes, are characterized mathematically as a small disturbance causing a large-amplitude response. Because of this, standard asymptotic and perturbation methods are ill-suited to these problems. In the present paper, a new method of analyzing jump phenomena is proposed. The principal feature of the method is the representation of the response in terms of rational functions. For illustration, the method is applied to the snap buckling of an elastic arch and to a simple combustion problem.

  13. 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)

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Shock phenomena in dusty plasmas of the Solar System

    NASA Astrophysics Data System (ADS)

    Popel, S. I.

    The results on shock phenomena in dusty plasmas of the Solar System are reviewed. The emphasis is given to the problems of dust ion acoustic bow shock in interaction of the solar wind with dusty cometary coma and formation of transient atmospheres of atmosphereless cosmic bodies such as Moon, Mercury, asteroids and comets. The latter assumes the evolution of meteoroid impact plumes and production of charged dust grains due to the condensation of both the plume substance and the vapor thrown from the crater and the surrounding regolith layer. Active rocket experiments, which involve the release of some gaseous substance in near-Earth space, are described. These experiments model physical phenomena occurring during large meteoroid impacts. New vistas in investigation of shock processes in space dusty plasmas are determined. This work was carried out within the Program of Fundamental Investigations of the Division of Earth Sciences of the Russian Academy of Sciences "Nanoparticles in Natural and Technogenic Systems" and was supported by the Russian Foundation for Basic Research, project no. 06-05-64826-a. One of the authors (S.I.P.) would like to thank the Russian Science Support Foundation for the grant in the nomination "Doctors of Science of the Russian Academy of Sciences".

  19. 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)

  20. 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.

  1. Displaying Computer Simulations Of Physical Phenomena

    NASA Technical Reports Server (NTRS)

    Watson, Val

    1991-01-01

    Paper discusses computer simulation as means of experiencing and learning to understand physical phenomena. Covers both present simulation capabilities and major advances expected in near future. Visual, aural, tactile, and kinesthetic effects used to teach such physical sciences as dynamics of fluids. Recommends classrooms in universities, government, and industry be linked to advanced computing centers so computer simulations integrated into education process.

  2. 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.

  3. 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

  4. 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...

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. Exoplanetary Atmospheres

    NASA Astrophysics Data System (ADS)

    Madhusudhan, N.; Knutson, H.; Fortney, J. J.; Barman, T.

    The study of exoplanetary atmospheres is one of the most exciting and dynamic frontiers in astronomy. Over the past two decades ongoing surveys have revealed an astonishing diversity in the planetary masses, radii, temperatures, orbital parameters, and host stellar properties of exoplanetary systems. We are now moving into an era where we can begin to address fundamental questions concerning the diversity of exoplanetary compositions, atmospheric and interior processes, and formation histories, just as have been pursued for solar system planets over the past century. Exoplanetary atmospheres provide a direct means to address these questions via their observable spectral signatures. In the last decade, and particularly in the last five years, tremendous progress has been made in detecting atmospheric signatures of exoplanets through photometric and spectroscopic methods using a variety of spaceborne and/or groundbased observational facilities. These observations are beginning to provide important constraints on a wide gamut of atmospheric properties, including pressure-temperature profiles, chemical compositions, energy circulation, presence of clouds, and nonequilibrium processes. The latest studies are also beginning to connect the inferred chemical compositions to exoplanetary formation conditions. In the present chapter, we review the most recent developments in the area of exoplanetary atmospheres. Our review covers advances in both observations and theory of exoplanetary atmospheres, and spans a broad range of exoplanet types (gas giants, ice giants, and super-Earths) and detection methods (transiting planets, direct imaging, and radial velocity). A number of upcoming planet-finding surveys will focus on detecting exoplanets orbiting nearby bright stars, which are the best targets for detailed atmospheric characterization. We close with a discussion of the bright prospects for future studies of exoplanetary atmospheres.

  11. 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)

  12. Atmospheric composition

    NASA Technical Reports Server (NTRS)

    Daniels, G. E.

    1973-01-01

    The earth's atmosphere is made up of a number of gases in different relative amounts. Near sea level and up to about 90 km, the amount of these atmospheric gases in clean, relatively dry air is practically constant. Four of these gases, nitrogen, oxygen, argon, and carbon dioxide, make up 99.99 percent by volume of the atmosphere. Two gases, ozone and water vapor, change in relative amounts, but the total amount of these two is very small compared to the amount of the other gases. The atmospheric composition shown in a table can be considered valid up to 90 km geometric altitude. Above 90 km, mainly because of molecular dissociation and diffusive separation, the composition changes.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Photoionization related phenomena in doped insulators

    NASA Astrophysics Data System (ADS)

    Kaplyanski, A. A.; Basun, S. A.; Happek, U.; Meltzer, R. S.; Salley, G. M.

    The light induced ionization of impurity centers and defects in insulating crystals results in many phenomena such as charge transfer optical transitions in absorption spectra, photoconductivity, the photovoltaic effect, optical bleaching, and photochemical persistent spectral hole burning. This paper considers specific effects in photoionization related phenomena which are closely connected with inversion symmetry of impurity centers. These recently observed effects include (a) the drastic dependence of the photoionization energy on impurity sites lacking inversion symmetry (Li2Ge7O15:Cr3+), (b) the direct dependence of the sign of the photovoltaic effect on the polarity of impurity sites in doped pyroelectric crystals (LiNbO3:Cr3+), and (c) the anomalous broadening of photochemical persistent spectral holes in zero-phonon spectra of inversionless impurity centers (CaS:Eu).

  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. Vector analysis of postcardiotomy behavioral phenomena.

    PubMed

    Caston, J C; Miller, W C; Felber, W J

    1975-04-01

    The classification of postcardiotomy behavioral phenomena in Figure 1 is proposed for use as a clinical instrument to analyze etiological determinants. The utilization of a vector analysis analogy inherently denies absolutism. Classifications A-P are presented as prototypes of certain ratio imbalances of the metabolic, hemodynamic, environmental, and psychic vectors. Such a system allows for change from one type to another according to the individuality of the patient and the highly specific changes in his clinical presentation. A vector analysis also allows for infinite intermediary ratio imbalances between classification types as a function of time. Thus, postcardiotomy behavioral phenomena could be viewed as the vector summation of hemodynamic, metabolic, environmental, and psychic processes at a given point in time. Elaboration of unknown determinants in this complex syndrome appears to be task for the future. PMID:1090426

  1. 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.

  2. 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

  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. Multiscale Phenomena in Biology and Scientific Perspectivism

    NASA Astrophysics Data System (ADS)

    Callebaut, Werner

    2009-09-01

    This paper is a plea for considering scientific perspectivism as the appropriate philosophical stance to deal with a number of epistemological, methodological, and ontological challenges modelers of complex, multi-scale phenomena are facing. Broadly speaking, perspectivism is the philosophical position that one's access to the world through perception, experience, and reason is possible only through one's own perspective and interpretation. Scientific perspectivism extends this position to scientific.

  5. 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.

  6. 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.

  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. 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.

  9. 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...

  10. 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.

  11. 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-Visl 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.

  12. Antarctic atmosphere

    NASA Astrophysics Data System (ADS)

    Lanzerotti, Louis J.

    The January 1983 issue of the Bulletin of the Scientific Committee on Antarctic Research (SCAR) contains information on the activities of the Working Group on Upper Atmosphere Physics that are of interest to U.S. scientists. This working group met during the 17th Meeting of SCAR held in Leningrad in July 1982. The working group noted that the southern polar region is uniquely significant in relation to the structure and dynamics of the middle atmosphere and therefore SCAR endorsed the coordinated, international Middle Atmosphere Program (MAP) in Antarctica.With regard to Antarctic data obtained during the International Magnetospheric Study (IMS), SCAR urged scientists to initiate international, bilateral, collaborative programs to extract important new results relevant to the IMS. The Secretary of the IAGA Interdivisional Commission on Antarctic Research (T. Hirasawa, National Institute for Polar Research, Tokyo) has available tabular information on IMS Antarctic data and programs. Similar information is contained on the 1982 IMS Source Book, published by AGU.

  13. Submarine atmospheres.

    PubMed

    Knight, D R; Tappan, D V; Bowman, J S; O'Neill, H J; Gordon, S M

    1989-12-01

    Nuclear submariners live and work in an atmosphere composed of approximately 80% naturally occurring nitrogen, 19% oxygen (manufactured aboard ship), and a complex mixture of inorganic and organic contaminants. The concentrations of contaminants exist as a balance between the rates of production from human and operational activities and the rate of removal by engineering systems. The biological effects of inorganic gases, particularly carbon dioxide, have been extensively studied. Investigators are now attempting to define the composition and concentration of volatile organic compounds that accumulate during 90-day submergences. Medical studies have not conclusively shown that crewmembers incur adverse health effects from continuous exposures to the sealed atmospheres of nuclear submarines. PMID:2574918

  14. Submarine atmospheres

    SciTech Connect

    Knight, D.R.; Tappan, D.V.; Bowman, J.S.; O'Neill, H.J.; Gordon, S.M.

    1990-07-01

    Nuclear submariners live and work in an atmosphere composed of approximately 80% naturally occurring nitrogen, 19% oxygen (manufactured aboard ship), and a complex mixture of inorganic and organic contaminants. The concentrations of contaminants exist as a balance between the rates of production from human and operational activities and the rate of removal by engineering systems. The biological effects of inorganic gases, particularly carbon dioxide, have been extensively studied. Investigators are now attempting to define the composition and concentration of volatile organic compounds that accumulate during 9O-day submergences. Medical studies have not conclusively shown that crewmembers incur adverse health effects from continuous exposures to the sealed atmospheres of nuclear submarines.

  15. 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.

  16. 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 of constant cross sectional area, and to facilitate fluid filling and draining operations in microgravity. The fluid cells may be used singly for bulk solutions, or in a Stokes diaphragm configuration to investigate membrane mediated phenomena. Thermal and electrical driving potentials are applied to the experiment fluids through boundary plates located at the ends of the fluid cells. In the ground based instrument, two constant temperature baths circulate through reservoirs adjacent to the boundary plates, and establish the thermal environment within the fluid cells. The boundary plates also serve as electrodes for measurement and application of electrical potentials. The Fluid Manipulation System associated with the MTA is a computer controlled system that enables storage and transfer of experiment fluids during on orbit operations. The system is used to automatically initiate experiments and manipulate fluids by orchestrating pump and valve operations through scripted sequences. Unique technologies are incorporated in the MTA for measurement of fluid properties. Volumetric Flow Sensors have been developed for precision measurement of total fluid volume contained within the fluid cells over time. This data is most useful for measuring the kinetics of osmosis, where fluid is transported from one fluid cell to another through a semipermeable membrane. The MicroSensor Array has been designed to perform in situ measurement of several important fluid parameters, providing simultaneous measurement of solution composition at multiple locations within the experiment fluids. Micromachined sensors and interface electronics have been developed to measure temperature, electrical conductivity, pH, cation activity, and anion activity. The Profile Refractometer uses a laser optical system to directly image the fluid Index of Refraction profile that exists along the MTA fluid cell axis. A video system acquires images of the RI profile over time, and records the transport kinetics that occur upon application of chemical, thermal, or electrical driving potentials. Image proces

  17. 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 electron has been among central topics of contempary condensed matter physics. Ultrfast phase transitions accompanied by switching of conductivity or magnetization in stronly correlated materials are believed to be promising in developing next generation of transistors. Our work on layered ruthenates has remarkably advanced our understanding of how the exotic phenomena of correlated electrons is governed by the complex interplay between charge, spin, lattice and orbital degrees of freedom. In addition to studies on ruthenates, we have also expanded our research to the emerging field of Fe-based superconductors, focusing on the iron chalcogenide Fe1+y(Te1-xSex) superconductor system. We first studied the superconductivity of this alloy system following the discovery of superconductivity in FeSe using polycrystalline samples. Later, we successfuly grew high-quality single crystals of these materials. Using these single crystals, we have determined the magnetic structure of the parent compound Fe1+yTe, observed spin resonance of superconducting state in optimally doped samples, and established a phase diagram. Our work has produced an important impact in this burgeoning field. The PI presented an invited talk on this topic at APS March meeting in 2010. We have published 19 papers in these two areas (one in Nature materials, five in Physical Review Letters, and nine in Physical Review B) and submitted two (see the list of publications attached below).

  18. Space Weather Phenomena at the Galilean Satellites

    NASA Astrophysics Data System (ADS)

    Cessateur, Gal; 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.

  19. Shock Tunnel Studies of Scramjet Phenomena

    NASA Technical Reports Server (NTRS)

    Stalker, R. J.

    1996-01-01

    Work focussed on a large number of preliminary studies of supersonic combustion in a simple combustion duct - thrust nozzle combination, investigating effects of Mach number, equivalence ratio, combustor divergence, fuel injecting angle and other parameters with an influence on the combustion process. This phase lasted for some three or four years, during which strongest emphasis was placed on responding to the request for preliminary experimental information on high enthalpy effects, to support the technology maturation activities of the NASP program. As the need for preliminary data became less urgent, it was possible to conduct more systematic studies of high enthalpy combustion phenomena, and to initiate other projects aimed at improving the facilities and instrumentation used for studying scramjet phenomena at high enthalpies. The combustion studies were particularly directed towards hypersonic combustion, and to the effects of injecting fuel along the combustion chamber wall. A substantial effort was directed towards a study of the effect of scale on the supersonic combustion process. The influence of wave phenomena (both compression waves and expansion waves) on the realization of thrust from a supersonic combustion process was also investigated. The effect of chemical kinetics was looked into, particularly as it affected the composition of the test flow provided by a ground facility. The effect of injection of the fuel through wall orifices was compared with injection from a strut spanning the stream, and the effect of heating the fuel prior to injection was investigated. Studies of fuel-air mixing by shock impingement were also done, as well as mass spectrometer surveys of a combustion wake. The use of hypersonic nozzles with an expansion tube was investigated. A new method was developed for measuring the forces acting of a model in less than one millisecond. Also included in this report are listings of published journal papers and conference presentations.

  20. 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.

  1. 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.

  2. 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.

  3. 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 quantum simulations performed in a liquid NMR QC.

  4. 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

  5. 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.

  6. BEAM COUPLING PHENOMENA IN FAST KICKER SYSTEMS.

    SciTech Connect

    ZHANG,W.; AHRENS,L.A.; GLENN,J.; SANDBERG,J.; TSOUPAS,N.

    2001-06-18

    Beam coupling phenomena have been observed in most fast kicker systems through out Brookhaven Collider-Accelerator complex. With ever-higher beam intensity, the signature of the beam becomes increasingly recognizable. The beam coupling at high intensity produced additional heat dissipation in high voltage modulator, thyratron grids, thyratron driver circuit sufficient to damage some components, and causes trigger instability. In this paper, we will present our observations, basic coupling mode analysis, relevance to the magnet structures, issues related to the existing high voltage modulators, and considerations of the future design of the fast kicker systems.

  7. 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.

  8. Generalized Bloch theorem and chiral transport phenomena

    NASA Astrophysics Data System (ADS)

    Yamamoto, Naoki

    2015-10-01

    Bloch theorem states the impossibility of persistent electric currents in the ground state of nonrelativistic fermion systems. We extend this theorem to generic systems based on the gauged particle number symmetry and study its consequences on the example of chiral transport phenomena. We show that the chiral magnetic effect can be understood as a generalization of the Bloch theorem to a nonequilibrium steady state, similarly to the integer quantum Hall effect. On the other hand, persistent axial currents are not prohibited by the Bloch theorem and they can be regarded as Pauli paramagnetism of relativistic matter. An application of the generalized Bloch theorem to quantum time crystals is also discussed.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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 Principal Component Analysis, PCA and Lomb-Scargle periodograms, LSP).

  15. Induction Phenomena in Laser-Sustained Scramjets

    SciTech Connect

    Ohkawa, Yoko; Tamada, Kazunobu; Horisawa, Hideyuki; Kimura, Itsuro

    2005-04-27

    A preliminary study on induction phenomena in a laser-sustained scramjet was conducted. The induction processes include absorption process of a laser pulse by a reactive mixture, plasma formation, diffusion of active species, shock formation, thermalization process of ambient mixture, induction of local turbulence, etc. For observation of the initial phenomena, an experimental study on effects of a focused laser pulse (Nd:YAG, 335mJ/pulse, pulse width 5nsec) into a hydrogen-air mixture was conducted. Temporal evolutions of typical line spectrum of a laser-induced plasma of the mixture were measured with the photodiode or the photo-multiplier-tube through specific band-pass filters for each spectrum for OH, O+, N+, H, and O. It was shown that the emission from O abruptly increased at 2 nsec, peaked at about 5 nsec, followed by an abrupt drop at 6 nsec. The emission from H atoms secondly increased. Other emissions of N+, O+, and OH peaked at about 17 nsec and continued for about 1 msec.

  16. Short pulse phenomena produced with long pulses

    NASA Astrophysics Data System (ADS)

    Hernndez, J. V.; Esry, B. D.

    2011-05-01

    We have found a way to produce to phenomena usually associated with ultrashort laser pulses using surprisingly long pulses. For example, the spatial asymmetry of a dissociating molecule has been observed to vary with the CEP for very short intense pulses. By using chirped pulses with large bandwidths, however, our calculations show large, CEP-dependent asymmetry in dissociating H2+even for 100 fs long pulses. This effect is also shown in the spatial asymmetry of an ionized atomic target. We also find varying the bandwidth and the direction of the chirp of the pulse can affect another multi-photon process, zero-photon dissociation of H2+.While it is not obvious how these unexpected phenomena can be explained in the usual time-dependent, field-based picture, their explanation in terms of a photon picture is rather straightforward, underscoring its utility even in the strong field regime. Supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy.

  17. Sonoluminescence and other energy focusing phenomena

    NASA Astrophysics Data System (ADS)

    Putterman, Seth

    2005-03-01

    Fluids and solids that are driven off equilibrium do not return smoothly to the equilibrium state. Instead they can display a wide range of energy focusing phenomena. In sonoluminescence a sound wave passing through a fluid has its energy concentrated by 12 orders of magnitude to create ultraviolet picosecond flashes of light. For 30KHz sound waves the spectrum is a blackbody yet its size is so small as to confound theory. At the very low frequencies achieved with a water hammer the strength of a single flash can be up-scaled by 6 orders of magnitude so as to be visible to this audience, in a real time demonstration. In a ferroelectric crystal such as Lithium Tantalate the application of heat leads to the expulsion of electrons with energies that can exceed 100KeV. Upon striking a target x-rays are emitted. A crucial question relates to whether there exist experimental configurations in which these processes can be used to generate nuclear fusion. Energy focusing also plays a role in turbulence, where intermittency leads to the formation of unexpected structures. Static electricity generated by friction is another striking example of an energy focusing effect. In the 'barometer light' dragging glass through mercury at a speed of 1mm/sec leads to picosecond electrical discharges where the electrons are accelerated to over 1% the speed of light. Experiments indicate that this effect is related to phenomena encompassed by everyday friction.

  18. 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.

  19. 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.

  20. Emergent Magnetic Phenomena at Manganite Interfaces

    NASA Astrophysics Data System (ADS)

    Suzuki, Yuri

    2015-03-01

    Emergent phenomena at transition metal oxide interfaces have been the focus of recent intense study since the discovery of metallicity at the interface of LaAlO3 and SrTiO3 a decade ago. Emergent magnetic phenomena at transition metal oxide interfaces had been studied even earlier. However there have been surprisingly few systems demonstrating interfacial ferromagnetism especially combined with metallicity. Recently, we have developed a general picture describing the origin of interfacial ferromagnetism in CaMnO3 based systems. Density functional theory attributed the interfacial ferromagnetism to a double exchange interaction among interfacial Mn ions (just in the first single unit cell of CaMnO3) mediated by conduction electrons from the neighboring itinerant layer. We have demonstrated interfacial ferromagnetism in superlattices composed of the antiferromagnetic insulator CaMnO3 and an itinerant metal (CaRuO3 or LaNiO3). Through polarized neutron spectrometry, x-ray magnetic circular dichroism and bulk magmetometry, we have shown that the ferromagnetism originates from Mn ions in a single unit cell of the CaMnO3 at the interfaces as theoretically predicted. The modulation of interfacial ferromagnetic moment as a function of constituent layer thicknesses as well as long-range antiferromagnetic correlations in the CaMnO3, observed by neutron diffraction, are indicative of the competing magnetic interactions at play.

  1. 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.

  2. Transition Phenomena in Networks of Quantum Systems

    NASA Astrophysics Data System (ADS)

    Kraus, B.; Trm, P.

    The advances in experimental manipulation and theoretical understanding of single quantum systems has fed the interest in quantum networks: quantum computers, quantum communication networks and multimode interferometers. According to statistical physics, a set of probabilistically behaving individual systems can exhibit critical behaviour when connected. In this paper we show that transition phenomena exist also in networks which behave probabilistically not because of finite temperature but due to their quantum nature1. We define a model which carries in its structure a formal analogy to the two-dimensional Ising-model. Such networks can be experimentally realized by various active (non-unitary) and passive (unitary) components. We give physical meaning to the transitions found. In the case of active components, such as amplifiers, the transition point coincides with the fundamental cloning limit given by quantum mechanics. We indicate how the transition phenomena could be observed, and discuss their significance and connection to quantum information related issues such as quantum computation and quantum cellular automata.

  3. 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 reactions in stars. In the most active galaxies known, the radiating accretion disc of the central SMBH engine easily outshines the stellar light of the entire galaxy (Blandford 1995). In addition to the light, plasma streams can emerge from the innermost regions at relativistic velocities, returning energy to the host galaxy (host) and creating jets and lobes with strong observational signatures, especially at radio and X-ray wavelengths (Wilson 2003). New insights in the wide field of SMBH/host interaction are often related to the development of new, more sensitive instruments and telescopes. For example the idea, that a high luminosity AGN may result from a merger event between two galaxies, could only develop with the upcoming high resolution and sensitive imaging capabilities needed to detect the highly distorted host galaxy morphologies of (post-)merger galaxies (Heckman et al. 1986). Furthermore multi-wavelength approaches, which combine the results of measurements at different wavelengths, often lead to new conclusions or confirm unsecured hypotheses. Thus developing a new instrument can be as valuable as combining different datasets. I follow both approaches and developed projects which (i) deal with new instrumentation and telescope technology, (ii) combine datasets from different wavelengths and resolutions, and (iii) incorporate recent theoretical models and predictions, which can be verified empirically. While some projects are more focused on investigating the power of new observational techniques, others incorporate acknowledged instruments to probe predictions based on previous observations and models and trace special phenomena of SMBH/host interaction. But in most cases aspects of all three items appear. The SMBH/host interaction results in phenomena at all linear size scales of the system, from the direct accretion of matter onto the central black hole up to radio jets crossing the entire galaxy. Thus interaction effects do not simply concentrate on the innermost region of a galaxy. Furthermore an increasing number of apparently totally distinct phenomena and properties of the SMBH/host system appear to be related to each other, provoking unifying ideas and models to explain the galaxy formation and evolution. For example several different types of AGN are understood as projection or orientation effects, claiming that the same AGN looks totally different as viewed from different sides (e.g. Antonucci & Miller 1985). The thesis is structured to reflect this general perception. All scales of size, AGN luminosity, and nuclear activity appear. The thesis consists of six chapters. The first two compile astrophysical and technical background of the individual projects, which themselves are presented in the following four chapters. While the first project (Chapter 3) deals with observations of the innermost parsec of our Galaxy, Chapter 4 presents data of the inner kpc of an active galaxy. The subjects of Chapters 5 and 6 are very luminous AGN/host systems, so-called QSOs. Whereas Chapter 5 presents global, spatially unresolved properties of SMBH/host systems, the radio jet, analyzed in the final Chapter 6, combines all size scales. It is investigated from close to its origin out to several kpc. The accretion onto the black hole of the Milky Way (Chapter 3) is extremely inefficient (Genzel et al. 2003a) and the SMBH possibly interacts dominantly via tidal forces only. The next discussed system (Chapter 4) is the prototype of moderately luminous Seyfert 2 AGN, NGC 1068. Here a strong local influence of the nuclear X-ray radiation is observed (Usero et al. 2004). Chapter 5 deals with the possible global importance of radiative interaction between highly luminous QSO AGN and the host. The radio jet in Chapter 6 definitely shows signs of interaction with the matter of its host several kpc away from the nucleus. Chapters 3-6 include a dedicated introductory and a conclusive section, which put the results obtained in the larger astrophysical context of the observation. The observational techniques chosen vary in dependence of the observed phenomenon. One major goal of especially Chapters 3 and 4 is to prove by successful explorative observations the scientific perspectives of the new instruments. Chapter 3 deals with the pioneering interferometric infrared study of stellar sources and their surroundings in the immediate vicinity of the SMBH at the center of the Milky Way. I was able to use the resolving power of an optical large baseline interferometer (OLBI) to investigate for the first time the different structures and excitation conditions of interstellar and circumstellar dust in 200 mpc distance to the SMBH. It is unknown whether the standard models for star and dust formation, which themselves dominate the infrared appearance of an inactive galaxy as the Milky Way, still apply under the strong tidal forces of gravity, exerted by the central SMBH. During the course of my doctoral research, I worked 2.5 years within the VLT Interferometry (VLTI) group of the European Southern Observatory (ESO) in M"unchen and Chile. I obtained the very first infrared fringes on GC sources and investigated the different instrument capabilities at the current sensitivity limit of the VLTI. The VLTI is the world leading stellar interferometric facility providing the infrastructure to combine the light of up to four 8m-class Adaptive Optics corrected telescopes, which themselves represent the state-of-the-art of optical-infrared telescope technology. The accomplished work includes the investigation of different data reduction techniques with respect to maximum accuracy and signal-to-noise ratios. The VLTI is right in the process of construction. While first modes are already open to the astronomical community, several advanced modes and instruments are still at different preliminary stages, ranging from early design studies to advanced instrument commissioning. The experiences of my VLTI observations, fully exploiting the currently available observing modes, and the data reduction were fed back via close collaboration to the Paranal Observatory and to the European science institutes of the instrument developing consortia1 . I contributed to improve the observing process (in particular to the infrared-based target acquisition of the instrument, and to the clarification of the chopping parameters) and the standard data reduction package (wavelength calibration, software debugging). The most recent NIR three-baseline observations of the GCIRS 7 helped to uncover imperfections in the numerical delay line model, which is needed to track the fringes during the observations. The smaller coherence lengths of these wide band observations were an ideal case to optimize the detector integration times for reaching highest signal-to-noise-ratios (SNR). The VLTI observations, described in Chapter 3, are the first observations of stellar interferometry in the infrared, which target objects through the 25 magnitudes of optical extinction along the line of sight toward the GC. One motivation for these observations, in addition to the direct scientific intention, was to create a showcase for advanced optical interferometry applications at the GC. An important part of the thesis is the detailed analysis of the achievable accuracy of the interferometric measurements. Such a precision study under the challenging conditions of off-axis optical AO guiding and faint target brightnesses close to the system limits has not been published before. Most of the interferometric observations were executed in the mid-infrared (MIR) wavelength regime at 10 μm (N -band), a natural starting point, because the optical requirements to the accuracy of the VLTI infrastructure are lower at these longer infrared wavelengths. The observed GCIRS 3 is an outstanding source at 10 μm being the most compact, brightest and isolated source at the GC. It bears significat signs of dust formation and will play a major role in understanding the dust formation and chemical properties of the local interstellar dust in the central parsec. The interferometric data of two observing seasons were interpreted together with different single telescope datasets. GCIRS 3 is known to be a very red luminous source, but no stellar spectrum could give away more detailed properties of the underlying source. I use a one-dimensional radiative transfer model to investigate the resolved dust shell properties, as observed with the 20 mas resolution of the VLTI at 10 μm. For the first time I can present results that show that the direct zone of dust formation around the deeply embedded star is observable. The temperature, derived from the spectral properties, and the spatial size, as derived from the high resolution interferometric dataset, show the cool star nature of the object. Earlier spatially unresolved N -band spectroscopic observations found a significant increase of oxygen rich silicate absorption towards GCIRS 3, deeper than towards the neighboring stars. The spectral properties of the VLTI data show that the immediate dust shell, formed by IRS 3 is not responsible for this strong absorption and might be devoid of a significant amount of silicate, favoring GCIRS 3 being a cool supergiant of ˜ 3000 K stellar temperature, forming more carbon-rich dust. The main impact of this result on GC science is, that the silicate-poor dust formation of GCIRS 3 and its silicate-rich surroundings appear to be the best place to study the extraordinary enrichment of the GC dust with interstellar amorphous silicate molecules (Roche & Aitken 1985). The dust formation in the nucleus of a galaxy is important, since only a detailed understanding of its composition helps to interpret the observed spectra and spectral energy distribution of spatially unresolved dusty nuclei of other galaxies. Furthermore the confirmed existence of a second massive red supergiant so close to GCIRS 7, which is already known to be a red supergiant, challenges the theories of star formation in galactic nuclei. Further currently possible VLTI-GC observations are presented in the following sections of Chapter 3. The dimensions of stellar bow-shocks are analyzed for the first time in the MIR to add information to the understanding of the kinematic features, which arise if massive stars with strong stellar winds ram into dense interstellar material. Such shock fronts can excite molecular hydrogen and add to the understanding of the excitation mechanisms in galactic nuclei (Pineau des Forêts et al. 2001). I show that such stellar bow-shocks are observable with the VLTI, and derive lower limits for their extension. Another set of first GC fringes was achieved in the near-infrared (NIR) at 2 μm on GCIRS 7. In one section of this chapter I describe the special importance of this star for future interferometric phase-referencing experiments. Despite of the technical problems occurred, fringes were found on one of the observed baseline, proving the feasibility of a detailed interferometric study of this putative phase calibrator in the near future. Phase referencing will significantly increase the number of observable targets, as soon as the respective hardware will be implemented. The following Chapter 4 reports on the first extragalactic sub-mm spectra of the innermost region in the Seyfert 2 prototype NGC 1068 with the new APEX telescope facility. The emission of the molecular rotational excitation lines CO(J=3-2) and HCN(J=4-3) were observed during the instrument testing phase. While the observations served for debugging the telescope operation, I prove that with dedicated data reduction already the current limited receiver capabilities are sufficient to measure broad extragalactic molecular line transitions in the sub-mm atmospheric transmission window. The observed lines are indispensable tracers of the warm and dense molecular gas (Papadopoulos & Seaquist 1999). The molecular gas is the major reservoir of matter in a galaxy, which supplies star formation and mass accretion onto the central SMBH. In Chapter 5, I present the results of the search for rotational line transitions at 80 GHz, in particular the 1-0 transition of the HCN molecule. It traces gas densities larger than 10e4/cm3 and is therefore a better quantitative tracers of the regions where star formation actually occurs than the stronger CO(1-0) transition, which correlates to the total amount of molecular gas which could be transformed into stars (Gao & Solomon 2004). The observed galaxies host a luminous quasar in their core. In nearby low luminosity AGN a relatively enhanced excitation of the HCN transition close to the central engine is observed (Usero et al. 2004). I investigate the hypothesis of an amplification and extension of this effect in high luminosity AGN from local nuclear to global galactic scales. Moreover the infrared luminosity ratios is used to trace global AGN dominance efficiently Then the detectability of enhanced HCN intensities due to intense nuclear X-ray irradiation and ionization is investigated. The measured upper limits are consistent with both normal and relatively enhanced HCN excitation. Quantitatively my results show that the detection of the expected HCN intensities in a statistically valuable sample of quasar host galaxies is within reach. In the last chapter, I analyze the physical properties of the radio jet in the radio loud quasar J1101+7225, which shows exceptionally far away from its nuclear origin (4 kpc) high relativistic motions. After a reanalysis of the cm-VLBI data, presented by Pott (2003), I include higher frequency data to follow the jet down to the hundred pc scale. The full analysis of the radio properties reveals an exemplary radio jet, which shows a complex inner structure including a possibly helical morphology. Far outside the nuclear region the jet rams into the host galaxy, which leads to a bending of the direction of propagation. Consequences for the galactic evolution of such interaction between the innermost accretion phenomenon and the surrounding host galaxy, which is typical for radio loud quasars, are not known yet. The diversity of the observations and results obtained gives an impression of the wide range of possible interactions between supermassive black holes and their host galaxies as well as of the many ways to observe them. Most of the presented results are published in peer-reviewed journals and presented at several conferences.

  4. 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.

  5. 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.

  6. 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 quantum states. In the tomographic picture of quantum mechanics, the states are identified with fair conditional probability distributions, which contain the same information on the states as the wave function or the density matrix. The mathematical methods of the tomographic approach are based on studying the star-product (associative product) quantization scheme. The tomographic star-product technique provides an additional understanding of the associative product, which is connected with the existence of specific pairs of operators called quantizers and dequantizers. These operators code information on the kernels of all the star-product schemes, including the traditional phase-space Weyl-Wigner-Moyal picture describing the quantum-system evolution. The new equation to find quantizers, if the kernel of the star product of functions is given, is presented in this CAMOP section. For studying classical systems, the mathematical methods developed in quantum mechanics can also be used. The case of paraxial-radiation beams propagating in waveguides is a known example of describing a purely classical phenomenon by means of quantum-like equations. Thus, some quantum phenomenon like the entanglement can be mimicked by the properties of classical beams, for example, Gaussian modes. The mathematical structures and relations to the symplectic symmetry group are analogous for both classical and quantum phenomena. Such analogies of the mathematical classical and quantum methods used in research on quantum-like communication channels provide new tools for constructing a theoretical basis of the new information-transmission technologies. The conventional quantum mechanics and its relation to classical mechanics contain mathematical recipes of the correspondence principle and quantization rules. Attempts to find rules for deriving the quantum-mechanical formalism starting from the classical field theory, taking into account the influence of classical fluctuations of the field, is considered in these papers. The methods to solve quantum equations and formulate the boundary conditions in the problems with singular potentials are connected with the mathematical problems of self-adjointness of the Hamiltonians. The progress and some new results in this direction are reflected in this CAMOP section. The Gaussian states of the photons play an important role in quantum optics. The multimode electromagnetic field and quantum correlations in the Gaussian states are considered in this section. The new results in the statistical properties of the laser radiation discussed here are based on applications of mathematical methods in this traditional domain of physics. It is worth stressing that the universality of the mathematical procedures permitted to consider the physical phenomena in the ocean is on the same footing as the phenomena in the microworld. In this CAMOP section, there are also papers devoted to traditional problems of solving the Schrödinger equation for interesting quantum systems. Recently obtained results related to different domains of theoretical physics are united by applying mathematical methods and tools, that provide new possibilities to better understand the theoretical foundations needed to develop new quantum technologies like quantum computing and quantum communications. The papers are arranged alphabetically by the name of the first author. We are grateful to all authors who accepted our invitation to contribute to this CAMOP section.

  7. 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 of constant cross sectional area, and to facilitate fluid filling and draining operations in microgravity. The fluid cells may be used singly for bulk solutions, or in a Stokes diaphragm configuration to investigate membrane mediated phenomena. Thermal and electrical driving potentials are applied to the experiment fluids through boundary plates located at the ends of the fluid cells. In the ground based instrument, two constant temperature baths circulate through reservoirs adjacent to the boundary plates, and establish the thermal environment within the fluid cells. The boundary plates also serve as electrodes for measurement and application of electrical potentials. The Fluid Manipulation System associated with the MTA is a computer controlled system that enables storage and transfer of experiment fluids during on orbit operations. The system is used to automatically initiate experiments and manipulate fluids by orchestrating pump and valve operations through scripted sequences. Unique technologies are incorporated in the MTA for measurement of fluid properties. Volumetric Flow Sensors have been developed for precision measurement of total fluid volume contained within the fluid cells over time. This data is most useful for measuring the kinetics of osmosis, where fluid is transported from one fluid cell to another through a semipermeable membrane. The MicroSensor Array has been designed to perform in situ measurement of several important fluid parameters, providing simultaneous measurement of solution composition at multiple locations within the experiment fluids. Micromachined sensors and interface electronics have been developed to measure temperature, electrical conductivity, pH, cation activity, and anion activity. The Profile Refractometer uses a laser optical system to directly image the fluid Index of Refraction profile that exists along the MTA fluid cell axis. A video system acquires images of the RI profile over time, and records the transport kinetics that occur upon application of chemical, thermal, or electrical driving potentials. Image processing algorithms have been developed to analyze the refractometer images on a pixel by pixel basis, calibrating and scaling the measured Index of Refraction profile to correlated solution properties of interest such as density, concentration, and temperature. Additional software has been developed to compile the processed images into a three dimensional matrix that contains fluid composition data as a function of experiment time and position in the fluid cell. These data are combined with data from the other sensor systems, and analyzed in the context of transport coefficients associated with the various transport phenomena. Analysis protocols have been developed to measure the transient kinetics, and steady state distribution of fluid components that occur in response to the applied driving potentials. The results are expressed in terms of effective transport coefficients. Experiments have been performed using a variety of solutes, and results generated are that are in agreement with published transport coefficient values.

  8. 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.

  9. [Phenomena and signaling mechanisms of macrophage reprogramming].

    PubMed

    Malyshev, I Yu

    2015-01-01

    The process of changing the phenotype of macrophages is called . Reprogramming plays a central role in the immune response. Reprogrammed macrophages are characterized by four phenomena: the phenomenon of the gain response of macrophages on the reprogramming factor (direct gain), and the other factor (cross-gain); phenomenon of reciprocal suppression of alternative phenotypes; phenomenon of cascade activation for mechanisms of reprogramming and the phenomenon of positive and negative feedbacks. The formation of these phenomena provide the intracellular signaling pathways, such as INK-; PI3K/Akt-; Notch-; JAK/STAT-; TGF-β-; TLR/NF-κB- and hypoxia-dependent signaling pathways. Analysis of the signaling mechanisms of reprogramming led to several conclusions: 1. There is a relative specialization of signaling pathways in macrophages reprogramming on action of different components of the microenvironment; 2. signaling pathways that are involved in reprogramming of macrophages can be divided in the way that program M1 phenotype and the way that program M2 phenotype; 3. Understanding the signaling pathways helps to explain the basic phenomena of reprogramming. Thus, the phenomenon of the gain response of reprogrammed macrophages is provided by convergence signaling pathways at specific protein; phenomenon of reciprocal suppression alternative macrophage phenotype is provided by that the formation of one phenotype is accompanied by increased synthesis of molecules that inhibit an alternative phenotype; at the heart of the phenomenon of cascade activation of signaling pathways is the ability one way to transmit signals over a different path and the basis for the phenomenon of positive and negative feedback is the ability to increase the synthesis of the activators and inhibitors of this pathway. 4. Signalling pathways that transmit the signal from the proinflammatory factors and programm proinflammatory M1 phenotype of macrophages are often branching, which, when activated, may increase the production of anti-inflammatory M2 cytokines; and vice versa. Since the violation reprogramming of macrophages plays an important role in the development of many diseases, understanding the signaling mechanisms of reprogramming, will assist in the selection of effective therapeutic targets to develop new ways of correction of impaired immunity. PMID:26571814

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. Hadronic and nuclear phenomena in quantum chromodynamics

    SciTech Connect

    Brodsky, S.J.

    1987-06-01

    Many of the key issues in understanding quantum chromodynamics involves processes at intermediate energies. We discuss a range of hadronic and nuclear phenomena - exclusive processes, color transparency, hidden color degrees of freedom in nuclei, reduced nuclear amplitudes, jet coalescence, formation zone effects, hadron helicity selection rules, spin correlations, higher twist effects, and nuclear diffraction - as tools for probing hadron structure and the propagation of quark and gluon jets in nuclei. Many of these processes can be studied in electroproduction, utilizing internal targets in storage rings. We also review several areas where there has been significant theoretical progress in determining the form of hadron and nuclear wavefunctions, including QCD sum rules, lattice gauge theory, and discretized light-cone quantization. 98 refs., 40 figs., 2 tabs.

  16. New biological phenomena associated with laser radiation

    SciTech Connect

    Belkin, M.; Schwartz, M.

    1989-05-01

    Low-energy laser irradiation produces significant bioeffects. These effects are manifested in biochemical, physiological and proliferative phenomena in various enzymes, cells, tissues, organs and organisms. Examples are given of the effect of He-Ne laser irradiation in preventing the post-traumatic degeneration of peripheral nerves and the postponement of degeneration of the central nervous system. The damage produced by similar radiant exposures to the corneal epithelium and endothelium is also described. It is suggested that the mechanism of laser/tissue interaction at these low levels of radiant exposure is photochemical in nature, explaining most of the characteristics of these effects. These low-energy laser bioeffects are of importance on a basic scientific level, from a laser safety aspect and as a medical therapeutic modality. 25 references.

  17. Critical phenomena in N=2* plasma

    SciTech Connect

    Buchel, Alex; Pagnutti, Chris

    2011-02-15

    We use gauge theory/string theory correspondence to study finite temperature critical behavior of mass-deformed N=4 SU(N) supersymmetric Yang-Mills theory at strong coupling, also known as N=2* gauge theory. For a certain range of the mass parameters, N=2* plasma undergoes a second-order phase transition. We compute all the static critical exponents of the model and demonstrate that the transition is of the mean-field theory type. We show that the dynamical critical exponent of the model is z=0, with multiple hydrodynamic relaxation rates at criticality. We point out that the dynamical critical phenomena in N=2* plasma is outside the dynamical universality classes established by Hohenberg and Halperin.

  18. 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.

  19. Surfactant-based critical phenomena in microgravity

    NASA Technical Reports Server (NTRS)

    Kaler, Eric W.; Paulaitis, Michael E.

    1994-01-01

    The objective of this research project is to characterize by experiment and theoretically both the kinetics of phase separation and the metastable structures produced during phase separation in a microgravity environment. The particular systems we are currently studying are mixtures of water, nonionic surfactants, and compressible supercritical fluids at temperatures and pressures where the coexisting liquid phases have equal densities (isopycnic phases). In this report, we describe experiments to locate equilibrium isopycnic phases and to determine the 'local' phase behavior and critical phenomena at nearby conditions of temperature, pressure, and composition. In addition, we report the results of preliminary small angle neutron scattering (SANS) experiments to characterize microstructures that exist in these mixtures at different fluid densities.

  20. 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.

  1. Superconductivity and superfluidity as universal emergent phenomena

    NASA Astrophysics Data System (ADS)

    Guidry, Mike; Sun, Yang

    2015-08-01

    Superconductivity (SC) or superfluidity (SF) is observed across a remarkably broad range of fermionic systems: in BCS, cuprate, iron-based, organic, and heavy-fermion superconductors, and in superfluid helium-3 in condensed matter; in a variety of SC/SF phenomena in low-energy nuclear physics; in ultracold, trapped atomic gases; and in various exotic possibilities in neutron stars. The range of physical conditions and differences in microscopic physics defy all attempts to unify this behavior in any conventional picture. Here we propose a unification through the shared symmetry properties of the emergent condensed states, with microscopic differences absorbed into parameters. This, in turn, forces a rethinking of specific occurrences of SC/SF such as high- T c SC in cuprates, which becomes far less mysterious when seen as part of a continuum of behavior shared by a variety of other systems.

  2. Physical Simulation: Testing the PHYSICALITY of Phenomena

    NASA Astrophysics Data System (ADS)

    Srivastava, Jagdish

    2004-05-01

    Theories of Quantum Mechanics in which `consciousness' plays a role have been around for decades. For example, Wheeler maintains that no phenomenon is a real phenomenon unless it has been observed. Also, the von Neumann chain, where the wave function is said to collapse when the chain reaches the mind of a conscious observer, is well known. The author's theory of Quantum Reality (denoted by TK) goes a bit further, saying that at the fundamental levels, all phenomena are logical-mathematical objects only, and the experience of their `physicality' is due to the consciousness of the observer. This paper addresses the question, as to how TK (and, the other related theories) could be tested. A procedure for this, termed `Physical Simulation' is proposed. The idea is to create logical-mathematical objects through a computer. Various aspects of this methodology are discussed.

  3. Simple phenomena, slow motion, surprising physics

    NASA Astrophysics Data System (ADS)

    Koupil, Jan; Vcha, Vladimr

    2011-07-01

    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 high-speed videos were taken using a Casio Exilim EX-F1 camera that can produce slow motion videos recorded at a rate of 1200 FPS (frames per second). When played back at the standard rate of 30 FPS, the motion is slowed down 40 times. The videos described in this article are accessible via http://bit.ly/slow-motion-physics.

  4. Density-functional theory of thermoelectric phenomena.

    PubMed

    Eich, F G; Di Ventra, M; Vignale, G

    2014-05-16

    We introduce a nonequilibrium density-functional theory of local temperature and associated local energy density that is suited for the study of thermoelectric phenomena. The theory rests on a local temperature field coupled to the energy-density operator. We identify the excess-energy density, in addition to the particle density, as the basic variable, which is reproduced by an effective noninteracting Kohn-Sham system. A novel Kohn-Sham equation emerges featuring a time-dependent and spatially varying mass which represents local temperature variations. The adiabatic contribution to the Kohn-Sham potentials is related to the entropy viewed as a functional of the particle and energy density. Dissipation can be taken into account by employing linear response theory and the thermoelectric transport coefficients of the electron gas. PMID:24877951

  5. 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.

  6. Novel nuclear phenomena in quantum chromodynamics

    SciTech Connect

    Brodsky, S.J.

    1987-08-01

    Many of the key issues in understanding quantum chromodynamics involve processes in nuclear targets at intermediate energies. A range of hadronic and nuclear phenomena-exclusive processes, color transparency, hidden color degrees of freedom in nuclei, reduced nuclear amplitudes, jet coalescence, formation zone effects, hadron helicity selection rules, spin correlations, higher twist effects, and nuclear diffraction were discussed as tools for probing hadron structure and the propagation of quark and gluon jets in nuclei. Several areas were also reviewed where there has been significant theoretical progress determining the form of hadron and nuclear wave functions, including QCD sum rules, lattice gauge theory, and discretized light-cone quantization. A possible interpretation was also discussed of the large spin correlation A/sub NN/ in proton-proton scattering, and how relate this effect to an energy and angular dependence of color transparency in nuclei. 76 refs., 24 figs.

  7. Boundary quantum critical phenomena with entanglement renormalization

    SciTech Connect

    Evenbly, G.; Pfeifer, R. N. C.; Tagliacozzo, L.; McCulloch, I. P.; Vidal, G.; Pico, V.; Iblisdir, S.

    2010-10-15

    We propose the use of entanglement renormalization techniques to study boundary critical phenomena on a lattice system. The multiscale entanglement renormalization ansatz (MERA), in its scale invariant version, offers a very compact approximation to quantum critical ground states. Here we show that, by adding a boundary to the MERA, an accurate approximation to the ground state of a semi-infinite critical chain with an open boundary is obtained, from which one can extract boundary scaling operators and their scaling dimensions. As in Wilson's renormalization-group formulation of the Kondo problem, our construction produces, as a side result, an effective chain displaying explicit separation of energy scales. We present benchmark results for the quantum Ising and quantum XX models with free and fixed boundary conditions.

  8. Psychic phenomena and early emotional states.

    PubMed

    Reiner, Annie

    2004-06-01

    This paper examines the relationship between severe early trauma and the development of psychic intuition. A case presentation with extensive dream work helps to illustrate this connection by exploring the psychological meaning of one patient's acute receptivity to unconscious communications. The paper includes a historical overview of Freud's attitudes toward occultism, as distinct from later psychoanalytic views, including those of Wilfred Bion. Many of Bion's views have more in common with Jung's perspective than with Freud's, with particular reference made to spiritual and religious differences. Bion clearly states that Freud and psychoanalysts have focused on phenomena, not on noumena, which Bion considers to be the essence of the psychoanalytic point of view. PMID:15149443

  9. Different atmospheric effects causing FSO link attenuation: experimental results and modelling in Czech Republic

    NASA Astrophysics Data System (ADS)

    Fiser, Ondrej; Brazda, Vladimir; Wilfert, Otakar

    2015-10-01

    The four year FSO link attenuation measurement concurrently with most important meteorological parameters was performed at our mountain observatory Milesovka. In this contribution we summarize and classify different atmospheric phenomena after the FSO link attenuation quantity. For all particular phenomena the CD curves, typical events and simple dependences on relevant atmospheric parameter(s) are presented. We consider the following phenomena (approximate specific attenuation in dB/km in brackets): 1. Fog and cloud (hundreds dB/km) 2. Rain and snow (tens dB/km) 3. Atmospheric turbulence (unit dB) 4. Clear air attenuation due to water vapour (unit dB or less)

  10. Can Observed Seismo-Electromagnetic Phenomena Be Explained By Known Mechano-Electromagnetic Mechanisms?

    NASA Astrophysics Data System (ADS)

    Gershenzon, Naum; Bambakidis, Gust

    2014-05-01

    Seismo-electromagnetism (SEM), in general, and lithospheric-atmospheric-ionospheric coupling in particular, continue to attract attention as possible earthquake precursors. Do these phenomena in fact exist? Currently there are no models which can explain a variety of electromagnetic observations before and after seismic events ranging from atmospheric light to electromagnetic field to ionosphere disturbances. Most existing models are qualitative, and quantitative estimates are usually superficial. Here we present the results of calculation of electromagnetic signals generated by modeled mechanical disturbances in the earth's crust. The major known SEM phenomena, namely, tectonomagnetic variations, electrotelluric anomalies, geomagnetic variations in the ultra-low frequency range and electromagnetic emission in the radio frequency range, have been considered. We discuss the conditions under which electro-kinetic, piezo-magnetic and piezo-electric effects could be responsible for SEM. A comparison of estimated values of SEMs with reported field measurements leads to the conclusion that, although these mechanisms may explain some of the observations, the sources of most anomalous SEM phenomena should be relatively close to the detector. In other words, the source of the signal is local, although the source of the mechanical disturbance which activates it, e.g. the epicenter of an earthquake, may be far away.

  11. Mesoscale modeling of the atmosphere

    NASA Astrophysics Data System (ADS)

    Pearce, R. P.

    1993-03-01

    The Naval Research Laboratory (NRL) is presently developing a non-hydrostatic mesoscale model which is suitable for forecasting meso-Beta and gamma scale phenomena over complex terrain. The model will be delivered to the Army in 1997. However, until the non-hydrostatic model becomes operational, HOTMAC (Higher Order Turbulence Model for Atmospheric Circulation) will be used as an operational model in the U.S. Army's IMETS (Integrated METeorological System) to make a short-range (up to 24 hours) forecast of battlescale atmospheric phenomena. The U.S. Army is mainly concerned with meteorological conditions spatially within the area of 500 km x 500 km x 10 km or less and temporally within the period of 24 hours or less. The Army Research Laboratory's (ARL) prototype IMETS is currently receiving the forecast and analysis fields of meteorological variables produced from the U.S. Air Force Global Spectral Model (GSM) through the Automated Weather Distribution System (AWDS). In the near future, the Relocatable Window Model (RWM) output is expected to become available. The RWM is the Air Force's regional meso-alpha model similar to the Navy Operational Regional Atmospheric Prediction System (NORAPS). The U.S. Army is planning to use the output of GSM (or RWM) to initialize and assimilate into HOTMAC. HOTMAC has been used extensively at the ARL (formerly Atmospheric Sciences Laboratory), and simulate the evolution of locally forced circulations due to surface heating and cooling over meso-Beta and gamma scale areas. HOTMAC is numerically stable and easy to use and thus, suitable for operational use.

  12. Atmospheric Illusion

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Believe it or not, this extreme close-up of Saturn's swirling clouds was acquired from more than one million kilometers (621,370 miles) from the gas giant planet. The rings' image is severely bent by atmospheric refraction as they pass behind the planet.

    The dark region in the rings is the 4,800-kilometer-wide (2,980 mile) Cassini Division.

    The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 25, 2005, at a distance of approximately 1 million kilometers (600,000 miles) from Saturn. The image scale is 6 kilometers (4 miles) per pixel.

  13. Very Low Frequency (VLF) studies of Ionospheric/Magnetospheric Electromagnetic phenomena in Indian Low Latitude Region using AWESOME Receivers

    NASA Astrophysics Data System (ADS)

    Singh, R.; Veenadhari, B.; Alex, S.

    2006-11-01

    Ground based observations of whistler mode ELF/VLF (300 Hz 30 kHz) waves are considered as an important remote sensing tool for the investigation of upper atmosphere and magnetosphere. These VLF waves find their origin in various natural and artificial phenomena, the natural sources include thunderstorms, lightning and associated phenomena. Despite of the fact that conjugate region of India having less lightning activity as it lies in Indian Ocean and also the height of the magnetic field lines connecting the conjugate regions lies in the ionosphere/atmosphere, lot of interesting VLF activity through the magnetosphere is observed in Indian low latitude region. Sub-ionospheric VLF transmissions propagating inside the Earth-ionosphere wave-guide is also being widely used for investigating sudden ionospheric perturbations in lower part of the ionosphere. For this purpose we propose to monitor VLF signals continuously at several locations in Indian sector with the help of AWESOME VLF receivers from Stanford University. AWESOME receivers are capable of collecting both broadband (used for the study of natural signals) and narrowband (sub-ionospheric VLF signals corresponding to VLF transmitters) data. The obtained data will enable us to understand the generation and propagation mechanism of radio atmospherics from lightning flashes, magnetospheric whistlers, VLF emissions and other naturally occurring phenomena. Narrowband sub- ionospheric VLF signals and ground based geomagnetic data in Indian low latitude region will help us to study sudden ionospheric disturbances associated with transient phenomena like solar flares, geomagnetic storms, cosmic gamma-ray flares, etc.

  14. Living matter: the "lunar eclipse" phenomena.

    PubMed

    Korpan, Nikolai N

    2010-01-01

    The present investigations describe a unique phenomenon, namely the phenomenon of the "lunar eclipse", which has been observed and discovered by the author in living substance during the freeze-thawing processes in vivo using temperatures of various intensities and its cryosurgical response in animal experiment. Similar phenomena author has observed in nature, namely the total lunar eclipse and total solar eclipse. In this experimental study 76 animals (mongrel dogs) were investigated. A disc cryogenic probe was placed on the pancreas after the laparotomy. For cryosurgical exposure a temperature range of -40 degrees C, -80 degrees C, -120 degrees C and -180 degrees C was selected in contact with pancreas parenchyma. The freeze-thaw cycle was monitored by intraoperative ultrasound before, during and after cryosurgery. Each cryolesion was observed for one hour after thawing intraoperatively. Immediately after freezing, during the thawing process, the snow-white pancreas parenchyma, frozen hard to an ice block and resembling a full moon with a sharp demarcation line, gradually assumed a ruby-red shade and a hemispherical shape as it grew in size depend on reconstruction vascular circulation from the periphery to the center. This snow-white cryogenic lesion dissolved in the same manner in all animal tissues. The "lunar eclipse" phenomenon contributes to a fundamental understanding of the mechanisms of biological tissue damage during low temperature exposure in cryoscience and cryomedicine. Properties of the pancreas parenchyma response during the phenomenon of the "lunar eclipse" provide important insights into the mechanisms of damage and the formation of cryogenic lesion immediately after thawing in cryosurgery. Vascular changes and circulatory stagnation are commonly considered to be the main mechanism of biological tissue injury during low temperature exposure. The phenomenon of the "lunar eclipse" suggests that cryosurgery is the first surgical technique to use anti-angiogenesis with an immediately following cryoaponecrosis and cryoapoptosis in the treatment of malignant tumor. Both the "lunar eclipse" in vivo as well as the similar phenomena, namely the total moon and total solar lunar eclipses, are is part of living nature. PMID:21485756

  15. Pathways toward understanding Macroscopic Quantum Phenomena

    NASA Astrophysics Data System (ADS)

    Hu, B. L.; Suba?i, Y.

    2013-06-01

    Macroscopic quantum phenomena refer to quantum features in objects of 'large' sizes, systems with many components or degrees of freedom, organized in some ways where they can be identified as macroscopic objects. This emerging field is ushered in by several categories of definitive experiments in superconductivity, electromechanical systems, Bose-Einstein condensates and others. Yet this new field which is rich in open issues at the foundation of quantum and statistical physics remains little explored theoretically (with the important exception of the work of A J Leggett [1], while touched upon or implied by several groups of authors represented in this conference. Our attitude differs in that we believe in the full validity of quantum mechanics stretching from the testable micro to meso scales, with no need for the introduction of new laws of physics.) This talk summarizes our thoughts in attempting a systematic investigation into some key foundational issues of quantum macroscopic phenomena, with the goal of ultimately revealing or building a viable theoretical framework. Three major themes discussed in three intended essays are the large N expansion [2], the correlation hierarchy [3] and quantum entanglement [4]. We give a sketch of the first two themes and then discuss several key issues in the consideration of macro and quantum, namely, a) recognition that there exist many levels of structure in a composite body and only by judicious choice of an appropriate set of collective variables can one give the best description of the dynamics of a specific level of structure. Capturing the quantum features of a macroscopic object is greatly facilitated by the existence and functioning of these collective variables; b) quantum entanglement, an exclusively quantum feature [5], is known to persist to high temperatures [6] and large scales [7] under certain conditions, and may actually decrease with increased connectivity in a quantum network [8]. We use entanglement as a measure of quantumness here and pick out these somewhat counter-intuitive examples to show that there are blind spots worthy of our attention and issues which we need to analyze closer. Our purpose is to try to remove the stigma that quantum only pertains to micro, in order to make way for deeper probes into the conditions whereby quantum features of macroscopic systems manifest.

  16. Temporal Variations in Jupiter's Atmosphere

    NASA Technical Reports Server (NTRS)

    Simon-Miller, Amy A.; Chanover, N. J.; Yanamandra-Fisher, P.; Hammel, H. B.; dePater, I.; Noll, K.; Wong, M.; Clarke, J.; Sanchez-Levega, A.; Orton, G. S.; Gonzaga, S.

    2009-01-01

    In recent years, Jupiter has undergone many atmospheric changes from storms turning red to global. cloud upheavals, and most recently, a cornet or asteroid impact. Yet, on top of these seemingly random changes events there are also periodic phenomena, analogous to observed Earth and Saturn atmospheric oscillations. We will present 15 years of Hubble data, from 1994 to 2009, to show how the equatorial tropospheric cloud deck and winds have varied over that time, focusing on the F953N, F41 ON and F255W filters. These filters give leverage on wind speeds plus cloud opacity, cloud height and tropospheric haze thickness, and stratospheric haze, respectively. The wind data consistently show a periodic oscillation near 7-8 S latitude. We will discuss the potential for variations with longitude and cloud height, within the calibration limits of those filters. Finally, we will discuss the role that large atmospheric events, such as the impacts in 1994 and 2009, and the global upheaval of 2007, have on temporal studies, This work was supported by a grant from the NASA Planetary Atmospheres Program. HST observational support was provided by NASA through grants from Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under contract NAS5-26555.

  17. International workshop on Time-Variable Phenomena in the Jovian System

    NASA Technical Reports Server (NTRS)

    Belton, Michael J. S.; West, R. A.

    1988-01-01

    Many of the scientifically interesting phenomena that occur in the Jovian system are strongly time variable. Some are episodic (e.g., Io volcanism); some are periodic (wave transport in Jupiters atmosphere); and some are exceedingly complex (magnetosphere - Io - Torus-Auroral interactions) and possibly unstable. To investigate this class of phenomena utilizing Voyager data and, in the future, Galileo results, a coherent program of ground based and earth-orbital observations, and of theory that spans the time between the missions, is required. To stimulate and help define the basis of such a scientific program researchers organized an International Workshop on the subject with the intent of publishing the proceedings which would represent the state of knowledge in 1987.

  18. Nonlinear phenomena in mechanical system dynamics

    NASA Astrophysics Data System (ADS)

    Warminski, J.; Kecik, K.; Mitura, A.; Bochenski, M.

    2012-08-01

    The goal of the paper is to present selected, untypical, and intuitively unexpected phenomena from nonlinear mechanics. Particular attention is paid to the dynamics of self-, parametric and external excited systems. Interactions between these various vibration types lead mainly to quasi-periodic responses. However, in the selected domains of system parameters, the effect of frequency locking is observed. Furthermore, external harmonic force imposed on such a system produces a specific internal loop inside a resonance zone. As an example of nonlinear autoparametric systems, a structure (oscillator) with an attached pendulum is presented. The nonlinear terms introduced by pendulum motion cause instabilities in the resonance region. This instability transits the pendulum to rotation or chaotic motion. An application of nonlinear couplings for the reduction of unwanted vibrations is also studied. In order to reduce vibrations, the main structure is coupled to an electrical oscillator by a quadratic term. It has been shown that such a coupling leads to the amplitude saturation phenomenon which can then be used to design a nonlinear control strategy.

  19. Rheological Properties and Transfer Phenomena of Nanofluids

    NASA Astrophysics Data System (ADS)

    Jung, Kang-min; Kim, Sung Hyun

    2008-07-01

    This study focused on the synthesis of stable nanofluids and investigation of their rhelogical properties and transfer phenomena. Nanofluids of diamond/ethylene glycol, alumina/transformer oil and silica/water were made to use in this study. Rheological properties of diamond nanofluids were determined at constant temperature (25 C) using a viscometer. For the convective heat transfer experiment, alumina nanofluid passed through the plate heat exchanger. CO2 absorption experiment was conducted in a bubble type absorber containing silica nanofluid. Diamond nanofluid showed non-Newtonian behaviors under a steady-shear flow except the case of very low concentration of solid nanoparticles. The heat transfer coefficient of alumina nanofluid was higher than that of base fluid. One possible reason is that concentration of nanoparticles at the wall side is higher than that of microparticles. Silica nanofluid showed that both average CO2 absorption rate and total absorption amount enhanced than those of base fluid. The stably suspended nanoparticles create a mesh-like structure. That structure arrangement cracks the gas bubble and increases the surface area.

  20. Half collision resonance phenomena in molecules

    SciTech Connect

    Maximo Garcia-Sucre ); Raseev, G. ); Ross, S.C. )

    1991-01-01

    The Escuela Latinoamericana de Fisica (ELAF) is a series of meeting s that for 28 years has played an important role in research-level teaching of physics in Latin America. This book contains the proceedings of ELAF 90 which was held at the Instituto Venezolano de Investigaciones Cientificas (IVIC) in Caracas, Venezuela from July 23 to August 3, 1990, as part of the commemoration of the 30th anniversary of IVIC. In contrast to previous ELAF's that were of general scope, ELAF 90 centered on a particular subject matter: Half Collisional Resonance Phenomena in Molecules, Experimental and Theoretical Approaches. The term Half Collision'' refers to the fragmentation of a molecular system following is excitation by light. The lack of an incident fragmentation of a molecular system following is excitation by light. The lack of an incident particle (other than the photon) in the fragmentation process is what leads to the term. The purpose of this volume is to present current results in the experimental and theoretical study of half collisions and also to include pedagogical papers at an introductory or intermediate level. The contributions are grouped into several sections; light sources; ionization; dissociation-experimental; dissociation-theory; competition between ionization and dissociation; and particle-molecule collisions.

  1. Phantom black holes and critical phenomena

    SciTech Connect

    Azreg-Aïnou, Mustapha; Marques, Glauber T.

    2014-07-01

    We consider the two classes cosh and sinh of normal and phantom black holes of Einstein-Maxwell-dilaton theory. The thermodynamics of these holes is characterized by heat capacities that may have both signs depending on the parameters of the theory. Leaving aside the normal Reissner-Nordström black hole, it is shown that only some phantom black holes of both classes exhibit critical phenomena. The two classes share a nonextremality, but special, critical point where the transition is continuous and the heat capacity, at constant charge, changes sign with an infinite discontinuity. This point yields a classification scheme for critical points. It is concluded that the two unstable and stable phases coexist on one side of the criticality state and disappear on the other side, that is, there is no configuration where only one phase exists. The sinh class has an extremality critical point where the entropy diverges. The transition from extremality to nonextremality with the charge held constant is accompanied by a loss of mass and an increase in the temperature. A special case of this transition is when the hole is isolated (microcanonical ensemble), it will evolve by emission of energy, which results in a decrease of its mass, to the final state of minimum mass and vanishing heat capacity. The Ehrenfest scheme of classification is inaccurate in this case but the generalized one due to Hilfer leads to conclude that the transition is of order less than unity. Fluctuations near criticality are also investigated.

  2. Efferent feedback can explain many hearing phenomena

    NASA Astrophysics Data System (ADS)

    Holmes, W. Harvey; Flax, Matthew R.

    2015-12-01

    The mixed mode cochlear amplifier (MMCA) model was presented at the last Mechanics of Hearing workshop [4]. The MMCA consists principally of a nonlinear feedback loop formed when an efferent-controlled outer hair cell (OHC) is combined with the cochlear mechanics and the rest of the relevant neurobiology. Essential elements of this model are efferent control of the OHC motility and a delay in the feedback to the OHC. The input to the MMCA is the passive travelling wave. In the MMCA amplification is localized where both the neural and tuned mechanical systems meet in the Organ of Corti (OoC). The simplest model based on this idea is a nonlinear delay line resonator (DLR), which is mathematically described by a nonlinear delay-differential equation (DDE). This model predicts possible Hopf bifurcations and exhibits its most interesting behaviour when operating near a bifurcation. This contribution presents some simulation results using the DLR model. These show that various observed hearing phenomena can be accounted for by this model, at least qualitatively, including compression effects, two-tone suppression and some forms of otoacoustic emissions (OAEs).

  3. Computational modelling of microfluidic capillary breakup phenomena

    NASA Astrophysics Data System (ADS)

    Li, Yuan; Sprittles, James; Oliver, Jim

    2013-11-01

    Capillary breakup phenomena occur in microfluidic flows when liquid volumes divide. The fundamental process of breakup is a key factor in the functioning of a number of microfluidic devices such as 3D-Printers or Lab-on-Chip biomedical technologies. It is well known that the conventional model of breakup is singular as pinch-off is approached, but, despite this, theoretical predictions of the global flow on the millimetre-scale appear to agree well with experimental data, at least until the topological change. However, as one approaches smaller scales, where interfacial effects become more dominant, it is likely that such unphysical singularities will influence the global dynamics of the drop formation process. In this talk we develop a computational framework based on the finite element method capable of resolving diverse spatio-temporal scales for the axisymmetric breakup of a liquid jet, so that the pinch-off dynamics can be accurately captured. As well as the conventional model, we discuss the application of the interface formation model to this problem, which allows the pinch-off to be resolved singularity-free, and has already been shown to produce improved flow predictions for related ``singular'' capillary flows.

  4. Rotary kilns - transport phenomena and transport processes

    SciTech Connect

    Boateng, A.

    2008-01-15

    Rotary kilns and rotating industrial drying ovens are used for a wide variety of applications including processing raw minerals and feedstocks as well as heat-treating hazardous wastes. They are particularly critical in the manufacture of Portland cement. Their design and operation is critical to their efficient usage, which if done incorrectly can result in improperly treated materials and excessive, high fuel costs. This book treats all engineering aspects of rotary kilns, including thermal and fluid principles involved in their operation, as well as how to properly design an engineering process that uses rotary kilns. Chapter 1: The Rotary Kiln Evolution and Phenomenon Chapter 2: Basic Description of Rotary Kiln Operation Chapter 3: Freeboard Aerodynamic Phenomena Chapter 4: Granular Flows in Rotary Kilns Chapter 5: Mixing and Segregation Chapter 6: Combustion and Flame - includes section on types of fuels used in rotary kilns, coal types, ranking and analysis, petroleum coke combustion, scrap tire combustion, pulverized fuel (coal/coke) firing in kilns, pulverized fuel delivery and firing systems. Chapter 7: Freeboard Heat Transfer Chapter 8: Heat Transfer Processes in the Rotary Kiln Bed Chapter 9: Mass and Energy Balance Chapter 10: Rotary Kiln Minerals Process Applications.

  5. Thermomechanical phenomena in high speed rubbing

    NASA Technical Reports Server (NTRS)

    Kennedy, F. E.

    1980-01-01

    An analytical approach is presented for the modeling of the thermomechanical interactions which occur in high speed sliding situations. These sliding contact problems which are characterized by active and interrelated thermal and mechanical phenomena could be called 'rub energetics' problems. Analytical models were developed to simulate two different rub situations: high energy braking of disk brakes and high speed rubs of gas path seals in turbine engines. The models proved to be particularly useful in predicting the severe temperatures and deformations near hot contact patches on the rubbing surfaces. The size of the hot patches is generally determined by normal load and the properties of the contacting materials. Temperatures at the contact patches can approach the melting point of the materials, especially at high sliding velocities. These high temperatures can lead to large amounts of near-surface deformation and high wear rates. Decreased contact temperatures can result from using materials with increased thermal conductivity and increased heat capacity or choosing mechanical properties (decreased stiffness, yield stress or coefficient of thermal expansion) which give larger hot spot size.

  6. Ultrashort Phenomena in Biochemistry and Biological Signaling

    NASA Astrophysics Data System (ADS)

    Splinter, Robert

    2014-11-01

    In biological phenomena there are indications that within the long pulse-length of the action potential on millisecond scale, there is additional ultrashort perturbation encoding that provides the brain with detailed information about the origin (location) and physiological characteristics. The objective is to identify the mechanism-of-action providing the potential for encoding in biological signal propagation. The actual molecular processes involved in the initiation of the action potential have been identified to be in the femtosecond and pico-second scale. The depolarization process of the cellular membrane itself, leading to the onset of the actionpotential that is transmitted to the brain, however is in the millisecond timeframe. One example of the femtosecond chemical interaction is the photoresponse of bacteriorhodopsin. No clear indication for the spatial encoding has so far been verified. Further research will be required on a cellular signal analysis level to confirm or deny the spatial and physiological encoding in the signal wave-trains of intercellular communications and sensory stimuli. The pathological encoding process for cardiac depolarization is however very pronounced and validated, however this electro-chemical process is in the millisecond amplitude and frequency modulation spectrum.

  7. Chemically Tunable Transport Phenomena of Functionalized Graphene

    NASA Astrophysics Data System (ADS)

    Leconte, Nicolas; Lherbier, Aurlien; Varchon, Francois; Charlier, Jean-Christophe; Palacios, Juan Jose; Soriano, David; Ordejon, Pablo; Roche, Stephan

    2012-02-01

    We present an ab initio multiscale study and quantum transport simulations using the Kubo formalism [1] of chemically modified graphene based materials, whose properties are tuned by changing the density and nature of grafted molecular units. Depending on the nature of the introduced molecular bonding different conduction mechanism are obtained, including transition from weak to strong Anderson localization [2,3], as well as spin-dependent phenomena [4] and magnetoresistive fingerprints [5]. [4pt] References: [1] H. Ishii, F. Triozon, N. Kobayashi, K. Hirose, and S. Roche, C. R. Physique 10, 283 (2009) [2] N. Leconte, J. Moser, P. Ordejon, H. Tao, A. Lherbier, A. Bachtold, F. Alsina, C.M. Sotomayor Torres, J.-C. Charlier, and S. Roche, ACS Nano 4, 7, 4033-4038 (2010) [3] N. Leconte, A. Lherbier, F. Varchon, P. Ordejon, S. Roche, and J.-C. Charlier (accepted in PRB) [4] N. Leconte, D. Soriano, S. Roche, P. Ordejon, J.-C. Charlier, and J.J. Palacios, ACS Nano 5, 5, 3987-3992 (2011) [5] D. Soriano, N. Leconte, P. Ordejon, J.-C. Charlier, J.J. Palacios, and S. Roche, Phys. Rev. Lett. 107, 016602 (2011)

  8. Some novel phenomena at high density

    NASA Astrophysics Data System (ADS)

    Berkowitz, Evan Scott

    Astrophysical environments probe matter in ways impossible on Earth. In particular, matter in compact objects are extraordinarily dense. In this thesis we discuss two phenomena that may occur at high density. First, we study toroidal topological solitons called vortons, which can occur in the kaon-condensed color-flavor-locked phase of high-density quark matter, a candidate phase for the core of some neutron stars. We show that vortons have a large radius compared to their thickness if their electrical charge is on the order of 104 times the fundamental charge. We show that shielding of electric fields by electrons dramatically reduces the size of a vorton. Second, we study an unusual phase of degenerate electrons and nonrelativistic Bose-condensed helium nuclei that may exist in helium white dwarfs. We show that this phase supports a previously-unknown gapless mode, known as the half-sound, that radically alters the material's specific heat, and can annihilate into neutrinos. We provide evidence that this neutrino radiation is negligible compared to the star's surface photoemission.

  9. The Monitoring of Transient Lunar Phenomena

    NASA Astrophysics Data System (ADS)

    Doorn, Jarrel; Eaton, M.; Ahrendts, G.; Barker, T.

    2011-05-01

    Transient Lunar Phenomena (TLP's) are described as short-lived changes in the brightness of areas on the face of the Moon. TLP activity has a higher number of reports, though unsubstantiated, in specific areas of the Moon such as the Aristarchus plateau. Our current research includes the division of lunar images taken through multiple filters using a Santa-Barbara Instrument Group (SBIG) ST8-E CCD camera mounted on a 0.45m Centurion telescope. We are also taking spectra of regions such as Aristarchus and the crater Ina, which shows evidence of recent activity (Schultz, P., Staid, M., Pieters, C. Nature, Volume 444, Issue 7116, pp. 184-186, 2006) using an SBIG DSS-7 spectrometer mounted on a 0.30m Schmidt-Cassegrain optical tube assembly on a Software Bisque Paramount drive system. Future research will include infrared imaging of the lunar surface. We are grateful for the support provided by the NASA Rhode Island Space Grant Consortium and the National Geographic Society.

  10. Interfacial critical phenomena in fluid mixtures

    NASA Astrophysics Data System (ADS)

    Peach, Sarah Elizabeth

    1997-06-01

    The slow dynamics of high molecular weight polymers have prevented extensive experimental testing of theoretical predictions for these systems. Critical phenomena of polymer solutions is one field in which, due to the lengthy requirements for attaining equilibrium, experiments are particularly scarce. A nonequilibrium method for the measurement of the interfacial tension of a phase-separated polymer solution was developed, and critical interfacial tension values were deduced without the need for long equilibration periods. Estimates of the timescales associated with the various equilibration processes were also obtained from nonequilibrium observations. In a separate series of reflectivity experiments, the wetting and adsorption behavior of a lightweight binary liquid mixture at a solid substrate were observed. By varying the strength of substrate-liquid interactions, via the chemical modification of the substrate, the adsorption properties were altered. In particular, the wetting transition temperatures were shifted and regimes of 'unsaturated' adsorption were observed. The unsaturated adsorption results were surprising enough to warrant an independent characterization of the substrate properties. Octadecyl-trichlorosilane was used to produce a uniform substrate with improved stability, allowing more precise adsorption measurements to be made. The characterization incorporated contact angle measurements and a combination of atomic and frictional force microscopy. The microscopy technique was specifically designed for the characterization of chemically and topographically heterogeneous substrates, and is therefore potentially useful for the analysis of a wide variety of surfaces.

  11. Basic ablation phenomena during laser thrombolysis

    NASA Astrophysics Data System (ADS)

    Sathyam, Ujwal S.; Shearin, Alan; Prahl, Scott A.

    1997-05-01

    This paper presents studies of microsecond ablation phenomena that take place during laser thrombolysis. The main goals were to optimize laser parameters for efficient ablation, and to investigate the ablation mechanism. Gelatin containing an absorbing dye was used as the clot model. A parametric study was performed to identify the optimal wavelength, spot size, pulse energies, and repetition rate for maximum material removal. The minimum radiant exposures to achieve ablation at any wavelength were measured. The results suggest that most visible wavelengths were equally efficient at removing material at radiant exposures above threshold. Ablation was initiated at surface temperatures just above 100 degrees Celsius. A vapor bubble was formed during ablation. Less than 5% of the total pulse energy is coupled into the bubble energy. A large part of the delivered energy is unaccounted for and is likely released partly as acoustic transients from the vapor expansion and partly wasted as heat. The current laser and delivery systems may not be able to completely remove large clot burden that is sometimes encountered in heart attacks. However, laser thrombolysis may emerge as a favored treatment for strokes where the occlusion is generally smaller and rapid recanalization is of paramount importance. A final hypothesis is that laser thrombolysis should be done at radiant exposures close to threshold to minimize any damaging effects of the bubble dynamics on the vessel wall.

  12. Two-Stage Modelling Of Random Phenomena

    NASA Astrophysics Data System (ADS)

    Bara?ska, Anna

    2015-12-01

    The main objective of this publication was to present a two-stage algorithm of modelling random phenomena, based on multidimensional function modelling, on the example of modelling the real estate market for the purpose of real estate valuation and estimation of model parameters of foundations vertical displacements. The first stage of the presented algorithm includes a selection of a suitable form of the function model. In the classical algorithms, based on function modelling, prediction of the dependent variable is its value obtained directly from the model. The better the model reflects a relationship between the independent variables and their effect on the dependent variable, the more reliable is the model value. In this paper, an algorithm has been proposed which comprises adjustment of the value obtained from the model with a random correction determined from the residuals of the model for these cases which, in a separate analysis, were considered to be the most similar to the object for which we want to model the dependent variable. The effect of applying the developed quantitative procedures for calculating the corrections and qualitative methods to assess the similarity on the final outcome of the prediction and its accuracy, was examined by statistical methods, mainly using appropriate parametric tests of significance. The idea of the presented algorithm has been designed so as to approximate the value of the dependent variable of the studied phenomenon to its value in reality and, at the same time, to have it "smoothed out" by a well fitted modelling function.

  13. Anomalous Magnetoresistance Phenomena in Organic Semiconductors

    NASA Astrophysics Data System (ADS)

    Bergeson, Jeremy D.; Lincoln, Derek M.; Shima Edelstein, Ruth; Prigodin, Vladimir N.; Epstein, Arthur J.

    2006-03-01

    We report magnetoresistance (MR) phenomena with temperature and bias dependence in organic semiconductor thin films with either nonmagnetic or magnetic contacts through high field reaching 9T. For nonmagnetic organic thin films such as Alq3 we find a low field MR up to 15%. A similar magnetic field effect has been reported earlier^1 but, as noted, the mechanism remains unclear. We propose a model of the anomalous MR where charge transport is space-charge limited. The current is determined by the e-h recombination rate. The recombination rate is field dependent, analogous to the chemical yield for radical pairs^2. Using an organic- based magnetic semiconductor^3, V[TCNE]x, and Co as magnetic contacts, with a nonmagnetic organic semiconductor (?-6T) leads to an order-of-magnitude broader zero-centered MR peak superimposed on a spin-valve effect. Possible origins of this broader MR will be discussed. 1. Francis, et al., New J. Phys. 6 185 (2004); Frankevich, et al., Phys. Rev. B 53 4498 (1996) 2. Steiner and Ulrich, Chem. Rev. 89 51 (1989) 3. Pokhodnya, et al., Adv. Mater. 12 410 (2000); Prigodin, et al., Adv. Mater. 14 1230 (2002); Shima Edelstein, et al., Mater. Res. Soc. Symp. Proc. 871E I7.3 (2005)

  14. Dynamical magnetoelectric phenomena of multiferroic skyrmions.

    PubMed

    Mochizuki, Masahito; Seki, Shinichiro

    2015-12-23

    Magnetic skyrmions, vortex-like swirling spin textures characterized by a quantized topological invariant, realized in chiral-lattice magnets are currently attracting intense research interest. In particular, their dynamics under external fields is an issue of vital importance both for fundamental science and for technical application. Whereas observations of magnetic skyrmions has been limited to metallic magnets so far, their realization was also discovered in a chiral-lattice insulating magnet Cu2OSeO3 in 2012. Skyrmions in the insulator turned out to exhibit multiferroic nature with spin-induced ferroelectricity. Strong magnetoelectric coupling between noncollinear skyrmion spins and electric polarizations mediated by relativistic spin-orbit interaction enables us to drive motion and oscillation of magnetic skyrmions by application of electric fields instead of injection of electric currents. Insulating materials also provide an environment suitable for detection of pure spin dynamics through spectroscopic measurements owing to the absence of appreciable charge excitations. In this article, we review recent theoretical and experimental studies on multiferroic properties and dynamical magnetoelectric phenomena of magnetic skyrmions in insulators. We argue that multiferroic skyrmions show unique coupled oscillation modes of magnetizations and polarizations, so-called electromagnon excitations, which are both magnetically and electrically active, and interference between the electric and magnetic activation processes leads to peculiar magnetoelectric effects in a microwave frequency regime. PMID:26624202

  15. Dynamical magnetoelectric phenomena of multiferroic skyrmions

    NASA Astrophysics Data System (ADS)

    Mochizuki, Masahito; Seki, Shinichiro

    2015-12-01

    Magnetic skyrmions, vortex-like swirling spin textures characterized by a quantized topological invariant, realized in chiral-lattice magnets are currently attracting intense research interest. In particular, their dynamics under external fields is an issue of vital importance both for fundamental science and for technical application. Whereas observations of magnetic skyrmions has been limited to metallic magnets so far, their realization was also discovered in a chiral-lattice insulating magnet Cu2OSeO3 in 2012. Skyrmions in the insulator turned out to exhibit multiferroic nature with spin-induced ferroelectricity. Strong magnetoelectric coupling between noncollinear skyrmion spins and electric polarizations mediated by relativistic spin–orbit interaction enables us to drive motion and oscillation of magnetic skyrmions by application of electric fields instead of injection of electric currents. Insulating materials also provide an environment suitable for detection of pure spin dynamics through spectroscopic measurements owing to the absence of appreciable charge excitations. In this article, we review recent theoretical and experimental studies on multiferroic properties and dynamical magnetoelectric phenomena of magnetic skyrmions in insulators. We argue that multiferroic skyrmions show unique coupled oscillation modes of magnetizations and polarizations, so-called electromagnon excitations, which are both magnetically and electrically active, and interference between the electric and magnetic activation processes leads to peculiar magnetoelectric effects in a microwave frequency regime.

  16. Further shock tunnel studies of scramjet phenomena

    NASA Technical Reports Server (NTRS)

    Morgan, R. G.; Paull, A.; Morris, N. A.; Stalker, R. J.

    1986-01-01

    Scramjet phenomena were studied using the shock tunnel T3 at the Australian National University. Simple two dimensional models were used with a combination of wall and central injectors. Silane as an additive to hydrogen fuel was studied over a range of temperatures and pressures to evaluate its effect as an ignition aid. The film cooling effect of surface injected hydrogen was measured over a wide range of equivalence. Heat transfer measurements without injection were repeated to confirm previous indications of heating rates lower than simple flat plate predictions for laminar boundary layers in equilibrium flow. The previous results were reproduced and the discrepancies are discussed in terms of the model geometry and departures of the flow from equilibrium. In the thrust producing mode, attempts were made to increase specific impulse with wall injection. Some preliminary tests were also performed on shock induced ignition, to investigate the possibility in flight of injecting fuel upstream of the combustion chamber, where it could mix but not burn.

  17. Atmosphere Analyzer

    NASA Technical Reports Server (NTRS)

    1982-01-01

    California Measurements, Inc.'s model PC-2 Aerosol Particle Analyzer is produced in both airborne and ground-use versions. Originating from NASA technology, it is a quick and accurate method of detecting minute amounts of mass loadings on a quartz crystal -- offers utility as highly sensitive detector of fine particles suspended in air. When combined with suitable air delivery system, it provides immediate information on the size distribution and mass concentrations of aerosols. William Chiang, obtained a NASA license for multiple crystal oscillator technology, and initially developed a particle analyzer for NASA use with Langley Research Center assistance. Later his company produced the modified PC-2 for commercial applications Brunswick Corporation uses the device for atmospheric research and in studies of smoke particles in Fires. PC-2 is used by pharmaceutical and chemical companies in research on inhalation toxicology and environmental health. Also useful in testing various filters for safety masks and nuclear installations.

  18. Natural phenomena hazards, Hanford Site, south central Washington

    SciTech Connect

    Tallman, A.M.

    1996-04-16

    This document presents the natural phenomena hazard (NPH) loads for use in implementing DOE Order 5480.28, Natural Phenomena Hazards Mitigation, at the Hanford Site in south-central Washington State. The purpose of this document is twofold: (1) summarize the NPH that are important to the design and evaluation of structures, systems, and components at the Hanford Site; (2) develop the appropriate natural phenomena loads for use in the implementation of DOE Order 5480.28. The supporting standards, DOE-STD-1020-94, Natural Phenomena Hazards Design and Evaluation Criteria for Department of Energy Facilities (DOE 1994a); DOE-STD-1022-94, Natural Phenomena Hazards Site Characteristics Criteria (DOE 1994b); and DOE-STD-1023-95, Natural Phenomena Hazards Assessment Criteria (DOE 1995) are the basis for developing the NPH loads.

  19. Research on atmospheric volcanic emissions - An overview

    NASA Technical Reports Server (NTRS)

    Friend, J. P.; Bandy, A. R.; Moyers, J. L.; Zoller, W. H.; Stoiber, R. E.; Torres, A. L.; Rose, W. I., Jr.; Mccormick, M. P.; Woods, D. C.

    1982-01-01

    Atmospheric abundances and the geochemical cycle of certain volatile compounds and elements may be largely influenced or entirely controlled by magmatic sources. However, better estimates of the magnitude and variability of volcanic emissions are required if the importance of this natural source of atmospheric constituents and the resulting effect on atmospheric chemistry are to be elucidated. The project 'Research on Atmospheric Volcanic Emissions' (RAVE) is concerned with the improvement of knowledge of both geological and chemical phenomena attending these emissions by means of comprehensive instrumentation on board a research aircraft making simultaneous measurements of plume constituents. A description is presented of the equipment and the procedures used in the RAVE field study of Mt. St. Helens' plume. An overview of the results is also provided.

  20. Magnetic Flux Emergence in the Solar Atmosphere

    NASA Astrophysics Data System (ADS)

    Cheung, Mark

    2015-08-01

    The emergence of magnetic flux from the solar interior into the atmosphere drives a diverse range of dynamic phenomena. In this talk, we review physical concepts important for understanding the flux emergence process and discuss advances drawn from a synthesis of observations and magnetohydrodynamics simulations. The development of data-driven models promises to bring the two approaches ever closer. Recent results and possibilities for future studies enabled by data-driven models will be discussed.

  1. Elucidating the underlying role of electron-driven processes in atmospheric phenomena

    NASA Astrophysics Data System (ADS)

    Brunger, Michael

    2005-05-01

    Electron-impact excitation plays an important role in emission from aurora and a less significant but nonetheless crucial role in the dayglow and nightglow. For some molecules, such as N2, O2 and NO, electron-impact excitation can be followed by radiative cascade through many different sets of energy levels, producing emission with a rich number of lines. We review the application of our enhanced statistical equilibrium program to predict this rich spectrum of radiation, and we compare results we have obtained against available independent measurements. Specific examples, including fundamental IR emission in NO, the 0.76?m O2 line and VUV emission in N2, will be chosen to highlight the underlying role of electron processes in their origin. Collaborators: L. Campbell and P.J.O. Teubner.

  2. FGK stars and T Tauri stars: Monograph series on nonthermal phenomena in stellar atmospheres

    NASA Technical Reports Server (NTRS)

    Cram, Lawrence E. (Editor); Kuhi, Leonard V. (Editor)

    1989-01-01

    The purpose of this book, FGK Stars and T Tauri Stars, like all other volumes of this series, is to exhibit and describe the best space data and ground based data currently available, and also to describe and critically evaluate the status of current theoretical models and physical mechanisms that have been proposed to interpret these data. The method for obtaining this book was to collect manuscripts from competent volunteer authors, and then to collate and edit these contributions to form a well structured book, which will be distributed to an international community of research astronomers by NASA and by the French CNRS.

  3. Study of phenomena related to the sintering process of silicon nitride at atmospheric pressure

    NASA Technical Reports Server (NTRS)

    Bertani, A.

    1982-01-01

    A procedure was perfected for the production of components used in engineering applications of silicon nitride. Particles of complex geometry that combine remarkable mechanical properties with a high density are obtained. The process developed, in contrast to the "hot pressing" method, does not use external pressures, and in contrast to the reaction bonding method, final densities close to the theoretical value are obtained.

  4. Investigation of collective phenomena in dusty plasmas

    NASA Astrophysics Data System (ADS)

    Ruhunusiri, Wellalage Don Suranga

    I study dusty plasma produced by electrostatically confining melamine formaldehyde microparticles in a radio-frequency glow discharge plasma. Dusty plasma is a mixture of particles of solid matter (dust), electrons, ions, and neutral gas atoms. The dust particles have a very high charge and a mass compared to the electrons and ions in the ambient plasma. As a consequence, a dusty plasma exhibits collective phenomena such as dust acoustic waves, crystallization, and melting. The discrete nature of dust particles gives rise to compressibility. In this thesis I report findings of four tasks that were performed to investigate dust acoustic waves, compressibility, and melting. First, the nonlinear phenomenon of synchronization was characterized experimentally for the dust acoustic wave propagating in a dust cloud with many layers. I find four synchronized states, with frequencies that are multiples of 1, 2, 3, and 1/2 of the driving frequency. Comparing to phenomena that are typical of the van der Pol paradigm, I find that synchronization of the dust acoustic wave exhibits the signature of the suppression mechanism but not that of the phaselocking mechanism. Additionally, I find that the synchronization of the dust acoustic wave exhibits three characteristics that differ from the van der Pol paradigm: a threshold amplitude that can be seen in the Arnold tongue diagram, a branching of the 1:1 harmonic tongue at its lower extremity, and a nonharmonic state. Second, to assess which physical processes are important for a dust acoustic instability, I derived dispersion relations that encompass more physical processes than commonly done. I investigated how various physical processes affect a dust acoustic wave by solving these dispersion relations using parameters from a typical dust acoustic wave experiment. I find that the growth rate diminishes for large ion currents. I also find that the compressibility, a measure of the coupling between the dust particles, have a strong effect on the wave propagation. Comparing the kinetic vs. hydrodynamic descriptions for ions, I find that under typical laboratory conditions the inverse Landau damping and the ion-neutral collisions contribute about equally to the dust acoustic instability. Third, I performed dust acoustic wave experiments to resolve a previously unremarked discrepancy in the literature regarding the sign of the compressibility of a strongly-coupled dust component in a dusty plasma. According to theories compressibility is negative, whereas experiments suggest that it is positive. I find that the compressibility is positive. This conclusion was reached after allowing for a wide range of experimental uncertainties and model dependent systematic errors. Finally, the polygon construction method of Glaser and Clark was used to characterize crystallization and melting in a single-layer dusty plasma. Using particle positions measured in a previous dusty plasma experiment, I identified geometrical defects, which are polygons with four or more sides. These geometrical defects are found to proliferate during melting. I also identify a possibility of latent heat involvement in melting and crystallization processes of a dusty plasma.

  5. Relaxation phenomena in human erythrocyte suspensions.

    PubMed Central

    Tsong, T Y; Tsong, T T; Kingsley, E; Siliciano, R

    1976-01-01

    Previous work has shown that the application of the Joule heating temperature jump technique of Eigen and de Maeyer to an istonic suspension of human erythrocytes induced an interiorization of [3H-A1glucose and a hemolysis of the red cells (Tsong, T.Y., and E. Kingsley, J. Biol. Chem. 250:786 [1975]). The result was interpreted as due to the thermal osmosis effect. Further considerations of the various effects of the Joule heating technique indicate that the hemolysis of the red cells may also be caused by the rapid dielectric perturbation of the cell membranes. By means of turbidity measurements of the suspensions we have detected at least four relaxation times. Two of the faster ones (tau1 approximately 20 mus and tau2 approximately 5 ms) are tentatively attributed to water relaxations in the membrane structures. The other two are attributed to membrane ruptures (tlag approximately 0.1s) and the hemolysis reaction (tau3 approximately 0.5 s). Studies with the erythrocytes from different hematological disorders indicate that whereas the two slower relaxations are sensitive to the overall physical property of the red cell membranes the two faster relaxations are not. These observations are consistent with the above assignment of the relaxation processes. The apparent activation energies are, above assignment of the relaxation processes. The apparent activation energies are, respectively, 8.4, 12.0, and 11.8 kcal/mol for the tau1, tau2, and tau3 reactions. Experiments with erythrocyte ghosts indicate a single relaxation for the water permeation, and biphasic kinetics for the membrane rupture and resealing reactions. The phenomena reported here may contribute to our understanding of water transport and molecular release in cellular systems. Images FIGURE 5 FIGURE 6 PMID:963205

  6. Three transport phenomena in molecular crystals

    NASA Astrophysics Data System (ADS)

    Dernis, Mitchell Stephen

    1997-07-01

    Modern spectroscopic techniques have moved beyond static structure determination, to studying the dynamics of molecular systems. I explore three areas of investigation into the transport phenomena in molecular crystals. The first section deals with a hydrogen tunneling reaction in the fluorene/acridine photosystem. A simple quantum mechanical model is developed that accurately models the main kinetic features of the reaction. This model relies on calculating Franck-Condon factors between normal modes of fluorene (including phonon modes), and a fictitious acceptor state which is chosen to appropriately represent an acceptor state with proper exothermicity. Both the temperature and pressure dependence are well fit. One area where the model fails is in predicting an increased kinetic sensitivity to pressure with increasing temperature. Instead, a simple and intuitive explanation is offered: the compressibility is most likely a function of temperature. The second section deals with spin diffusion in a deep trap excited triplet state spin system. Isotopic effects on the decay rates of two and three pulse echoes are systematically studied in benzene doped with pyrimidine. Upon full deuteration seven fold and four fold increases in echo decay time are observed for two pulse and three pulse echoes, respectively. When fit to the Hu Hartman model, the three pulse echo data yields anomalously low spin flip rates (tens of Hz) for the bulk nuclei. Typical bulk nuclei flip at tens of kHz. These data are interpreted as being characteristic of nuclear spins within the detuned sphere. Based on this assumption, reasonable hyperfine coupling constants are calculated for these near spins. The final section is a small step on a work in progress. We set out to measure the dispersion of TCB's vibron bands under pressure. Building on a technique developed by J. Schmidt, we attempt to measure the phosphorescence emission of the exciton after singlet to triplet absorption. Our lack of success is attributed to the high vulnerability of TCB crystals to strain induced defects.

  7. CFD Analysis of Core Bypass Phenomena

    SciTech Connect

    Richard W. Johnson; Hiroyuki Sato; Richard R. Schultz

    2010-03-01

    The U.S. Department of Energy is exploring the potential for the VHTR which will be either of a prismatic or a pebble-bed type. One important design consideration for the reactor core of a prismatic VHTR is coolant bypass flow which occurs in the interstitial regions between fuel blocks. Such gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The existence of the gaps induces a flow bias in the fuel blocks and results in unexpected increase of maximum fuel temperature. Traditionally, simplified methods such as flow network calculations employing experimental correlations are used to estimate flow and temperature distributions in the core design. However, the distribution of temperature in the fuel pins and graphite blocks as well as coolant outlet temperatures are strongly coupled with the local heat generation rate within fuel blocks which is not uniformly distributed in the core. Hence, it is crucial to establish mechanistic based methods which can be applied to the reactor core thermal hydraulic design and safety analysis. Computational Fluid Dynamics (CFD) codes, which have a capability of local physics based simulation, are widely used in various industrial fields. This study investigates core bypass flow phenomena with the assistance of commercial CFD codes and establishes a baseline for evaluation methods. A one-twelfth sector of the hexagonal block surface is modeled and extruded down to whole core length of 10.704m. The computational domain is divided vertically with an upper reflector, a fuel section and a lower reflector. Each side of the sector grid can be set as a symmetry boundary

  8. CFD Analysis of Core Bypass Phenomena

    SciTech Connect

    Richard W. Johnson; Hiroyuki Sato; Richard R. Schultz

    2009-11-01

    The U.S. Department of Energy is exploring the potential for the VHTR which will be either of a prismatic or a pebble-bed type. One important design consideration for the reactor core of a prismatic VHTR is coolant bypass flow which occurs in the interstitial regions between fuel blocks. Such gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The existence of the gaps induces a flow bias in the fuel blocks and results in unexpected increase of maximum fuel temperature. Traditionally, simplified methods such as flow network calculations employing experimental correlations are used to estimate flow and temperature distributions in the core design. However, the distribution of temperature in the fuel pins and graphite blocks as well as coolant outlet temperatures are strongly coupled with the local heat generation rate within fuel blocks which is not uniformly distributed in the core. Hence, it is crucial to establish mechanistic based methods which can be applied to the reactor core thermal hydraulic design and safety analysis. Computational Fluid Dynamics (CFD) codes, which have a capability of local physics based simulation, are widely used in various industrial fields. This study investigates core bypass flow phenomena with the assistance of commercial CFD codes and establishes a baseline for evaluation methods. A one-twelfth sector of the hexagonal block surface is modeled and extruded down to whole core length of 10.704m. The computational domain is divided vertically with an upper reflector, a fuel section and a lower reflector. Each side of the one-twelfth grid can be set as a symmetry boundary

  9. Impact vaporization: Late time phenomena from experiments

    NASA Technical Reports Server (NTRS)

    Schultz, P. H.; Gault, D. E.

    1987-01-01

    While simple airflow produced by the outward movement of the ejecta curtain can be scaled to large dimensions, the interaction between an impact-vaporized component and the ejecta curtain is more complicated. The goal of these experiments was to examine such interaction in a real system involving crater growth, ejection of material, two phased mixtures of gas and dust, and strong pressure gradients. The results will be complemented by theoretical studies at laboratory scales in order to separate the various parameters for planetary scale processes. These experiments prompt, however, the following conclusions that may have relevance at broader scales. First, under near vacuum or low atmospheric pressures, an expanding vapor cloud scours the surrounding surface in advance of arriving ejecta. Second, the effect of early-time vaporization is relatively unimportant at late-times. Third, the overpressure created within the crater cavity by significant vaporization results in increased cratering efficiency and larger aspect ratios.

  10. Atmospheric electricity

    NASA Technical Reports Server (NTRS)

    1987-01-01

    In the last three years the focus was on the information contained in the lightning measurement, which is independent of other meteorological measurements that can be made from space. The characteristics of lightning activity in mesoscale convective systems were quantified. A strong relationship was found between lightning activity and surface rainfall. It is shown that lightning provides a precursor signature for wet microbursts (the strong downdrafts that produce windshears hazardous to aircraft) and that the lightning signature is a direct consequence of storm evolution. The Universities Space Research Association (USRA) collaborated with NASA scientists in the preliminary analysis and scientific justification for the design and deployment of an optical instrument which can detect lightning from geostationary orbit. Science proposals for the NASA mesoscale science program and for the Tethered Satellite System were reviewed. The weather forecasting research and unmanned space vehicles. Software was written to ingest and analyze the lightning ground strike data on the MSFC McIDAS system. The capabilities which were developed have a wide application to a number of problems associated with the operational impacts of electrical discharge within the atmosphere.

  11. Solidification phenomena in metal matrix nanocomposites

    NASA Astrophysics Data System (ADS)

    de Cicco, Michael Peter

    2009-12-01

    Nanoparticles in metal matrix nanocomposites (MMNCs) were shown to act as catalysts for nucleation of solidification of the matrix alloy, as well as to alter the intermetallic phase formation. These phenomena were studied in zinc, aluminum, and magnesium alloys. In all alloys studied, a refinement of the microstructure was seen with the addition of the nanoparticles. Various types of nanoparticles were used and had varying degrees of refinement. In a zinc alloy, AC43A, SiC, TiC, and Al2O3 gamma nanoparticles were all found to refine the alloy. Thermal analysis of bulk samples showed the onset of solidification at reduced undercoolings, indicating nucleation catalysis. Nucleation of the primary phase was also observed by employing the droplet emulsion technique (DET). DET results showed that the secondary phase nucleation was also catalyzed by the nanoparticles. Exploiting the nucleation catalysis of the nanoparticles and the associated grain refinement, a semi-solid casting (SSC) process was demonstrated in AC43A + SiC nanocomposites. This novel process successfully incorporated the strength enhancement of MMNCs and the casting quality benefits of SSC. This process required no additional processing steps or material handling typical of existing SSC processes. The nucleation catalysis of the nanoparticles was sufficient to create semi-solid slurries appropriate for SSC. Nanoparticle induced nucleation catalysis was also examined in a common aluminum alloy, A356, using the DET. All nanoparticles catalyzed nucleation of the primary Al phase. However, undercoolings varied depending on the nanoparticle identity and average diameter. The variation in undercoolings generally agreed with a modified lattice disregistry theory and the free growth theory. For nanoparticles with a small lattice spacing mismatch with the Al phase, undercoolings approached the size dependent free growth limit. Binary alloys of magnesium and zinc showed significant strength and ductility enhancements with the addition of 1.5 weight % SiC nanoparticles. Transmission electron microscope (TEM) study of the nanocomposite showed the MgZn2 phase among the nanoparticles and a reduction of the Mg 7Zn3 and Mg2Zn3 phases that were common in the monolithic samples. Thermal analysis supported this observed phase selection. The demonstrated nucleation catalysis and phase selection resulted in processing and property enhancement in the MMNCs.

  12. Saving the Phenomena in Medieval Astronomy

    NASA Astrophysics Data System (ADS)

    Seeskin, K.

    2011-06-01

    Aristotle's theory of motion is based on two principles: (1) all motion to either from the midpoint of the Earth, toward it, or around it, and (2) circular motion must proceed around an immovable point. On this view, the heavenly bodies are individual points of light carried around by a series of concentric spheres rotating at a constant pace around the midpoint of the Earth. But even in Aristotle's day, it was known that this theory had a great deal of difficulty accounting for planetary motion. Ptolemy's alternative was to introduce epicycles and eccentric orbits, thus denying Aristotle's view of natural motion. There was no doubt that Ptolemy's predictions were far better than Aristotle's. But for the medievals, Aristotle's theory made better intuitive sense. Moreover, Ptolemy's theory raised the question of how one sphere could pass through another. What to do? The solution of Moses Maimonides (1138-1204) was to say that it is not the job of the astronomer to tell us how things actually are but merely to propose a series of hypotheses that allow us to explain the relevant data. This view had obvious theological implications. If astronomy could explain planetary motion in an acceptable way, there was reason to believe that the order or structure of the heavens is what it is by necessity. This suggests that God did not exercise any degree of choice in making it that way. But if astronomy cannot explain planetary motion, the most reasonable explanation is that we are dealing with contingent phenomena rather than necessary ones. If there is contingency, there is reason to think God did exercise a degree of choice in making the heavens the way they are. A God who exercises choice is much closer to the God of Scripture. Although Galileo changed all of this, and paved the way for a vastly different view of astronomy, the answer to one set of questions raises a whole different set. In short, the heavenly motion still poses ultimate questions about God, existence, and the origin of the universe.

  13. Investigations of Induced Charge Electrokinetic Phenomena

    NASA Astrophysics Data System (ADS)

    Pascall, Andrew James

    Recent developments in microfluidics have highlighted the importance of efficiently transporting fluids at the micron scale. This has lead to a resurgence of interest in utilizing electrokinetic phenomena, which scale favorably with the small channel dimensions encountered in microfluidics, to drive fluid flows. This dissertation focuses on induced charge electro-osmosis (ICEO), a nonlinear electrokinetic effect in which an applied electric field both induces and drives a layer of charged fluid near an electrically conductive surface. ICEO has been shown to produce time-averaged flows with AC electric fields and may provide an on-chip means of generating high pressure flows with low applied voltages. Experimental studies of ICEO have shown that standard theories generally overpredict the observed slip velocity, frequently by orders of magnitude. This discrepancy could be explained by the presence of a thin coating of an adventitious dielectric over the conductive surface. In this work, I develop a modified theory of ICEO that incorporates the effects of a dielectric coating and its surface chemistry, both of which act to decrease the slip velocity relative to a clean metal. This theory shows that a layer of dielectric contaminant of only nanometer thickness can lead to significantly suppressed ICEO flows. In order to test this theory, I developed a novel experimental apparatus, the details of which are presented herein, that allows for the observation of ICEO flows over planar surfaces coated with dielectrics of controlled physical properties. Data for over 8000 combinations of parameters over both an oxide dielectric and alkanethiol self-assembled monolayer show unprecedented quantitative agreement with this modified theory. The goal for engineering practical microfluidic devices is to generate the fastest flows possible for a given set of conditions. I end the dissertation with a discussion of how to generate flows that are orders of magnitude faster than those over a solid surface by using thin liquid films. This result follows from the fact that the electrical stress in the electrolyte drives the electrolyte/thin film interface itself into motion.

  14. Optical studies of critical phenomena in fluids

    NASA Astrophysics Data System (ADS)

    Fameli, Nicola

    2000-11-01

    Accurate optical techniques were employed to study the behaviour of the binary liquid mixture n-heptane+nitrobenzene (C 7H16 + C6 H5NO2) and of the pure fluid 1,1-difluoroethylene (C2H 2F2) near their respective critical regions. It is found that, in the region of reduced temperature, t = (Tc -- T)/T c < 3 x 10--4, the order parameter Deltaφ H for the binary mixture follows a power law Deltaφ H ≈ tbeta, with a leading exponent beta = 0.367 +/- 0.006, which is higher than the predicted theoretical value of beta = 0.326 +/- 0.002. A careful study of the effect of refractive index gradients caused by the Earth's gravitational field, potential variation of the optical thickness of the sample cells due to wetting of the cell walls by one the phases, and the long thermal equilibration times of binary mixtures has failed to resolve the disagreement between beta measured on n-heptane+nitrobenzene and its theoretical value. A significant feature of this investigation is the novel application of an optical technique (the image plane technique) for studying critical phenomena in transparent binary liquids. The Lorentz-Lorenz function, £, of 1,1-difluoroethylene was measured in order to determine the fluid's density from its refractive index. The quantity £ is found to vary by about 1.4% with density of the fluid, rho, with a gentle maximum at a density slightly higher than the critical density, rho c. The density measurements were then used to construct the coexistence curve for this material. The coexistence curve of C2H 2F2 was measured with the 'Lorentz-Lorenz' experiment and with a new apparatus combining two complementary optical methods, the prism cell technique and the focal plane technique, into one. The measurements carried out on C2H2 F2 in this thesis serve as a test of this apparatus. The order parameter data of C2H 2F2 are described accurately by a scaling power law in terms of the reduced temperature t, with the critical exponents at their theoretical values. The coexistence curve data taken simultaneously with the two combined techniques agree well with each over the whole range of temperature investigated.

  15. Interlayer interaction phenomena in novel materials

    NASA Astrophysics Data System (ADS)

    Pershoguba, Sergii

    Recently, there has been a considerable interest in various novel two-dimensional (2D) materials, such as graphene, topological insulators, etc. These materials host a plethora of exotic phenomena owing to their unconventional electronic structure. Physics of these 2D materials is understood fairly well, so a natural generalization is to assemble these materials into three-dimensional (3D) stacks. In this thesis, we study a number of multilayer systems, where the interlayer interaction plays a salient role. We commence with studying graphene multilayers coupled via interlayer tunneling amplitude. We calculate the energy spectrum of the system in magnetic field B parallel to the layers. The parallel magnetic field leads to a relative gauge shift of the momentum spaces of the individual 2D layers. When the interlayer tunneling is introduced, we find the Landau levels. We observe two qualitatively distinct domains in the Landau spectrum and analyze them using semiclassical arguments. Then, we include electric field E perpendicular to the layers, and analyze the spectrum in the crossed-field geometry. If the fields are in resonance E = upsilon B, where upsilon is the velocity of carriers in graphene, the wave-functions delocalize in the direction along the field E. We compare this prediction to a tunneling spectroscopy study of a graphite mesa in the parallel magnetic field. Indeed, the tunneling spectrum displays a peak, which grows linearly with the applied magnetic field B, and is, thus, consistent with our theoretical analysis. Then, we move on to a discussion of Z2 topological insulators within the Shockley model. We generalize the one dimensional (1D) Shockley model by replacing atomic sites of the original model by the 2D Rashba spin-orbit layers. We analyze surface states of a topological insulator using a construction of vortex lines in the 3D momentum space. We also study a topological insulator in a thin film geometry, where the opposite surface states are coupled by the tunneling amplitude. We calculate the tunneling current between the opposite surfaces and a spin polarization of the current as a function of the in-plane magnetic field. We conclude with studying a novel chiral order in cuprates. We construct a helical interlayer pattern of loop-currents. The interlayer magnetic coupling and magnetoelectric effect lead to optical gyrotropy.

  16. Pendulum Phenomena and the Assessment of Scientific Inquiry Capabilities

    ERIC Educational Resources Information Center

    Zachos, Paul

    2004-01-01

    Phenomena associated with the "pendulum" present numerous opportunities for assessing higher order human capabilities related to "scientific inquiry" and the "discovery" of natural law. This paper illustrates how systematic "assessment of scientific inquiry capabilities", using "pendulum" phenomena, can provide a useful tool for classroom teachers

  17. Low energy electron collision parameters for modeling auroral/dayglow phenomena

    NASA Astrophysics Data System (ADS)

    Malone, Charles P.

    2011-10-01

    From the tenuous atmospheres of Pluto and Triton to the higher pressure atmospheres of Earth and Titan, electron-collisions with molecular nitrogen continue to warrant attention. The airglow emissions of N2 from the atmospheres of Earth and planetary satellites have been extensively observed. Accurate, consistent cross section data is a necessity for accurate models of how upper atmospheres behave. This enables determinations of solar energy inputs and atmospheric expansion and contraction, which influences satellite orbits for instance. Recent work by Lean et al., Stevens et al., and Kato et al. appear to substantiate our e-+N2 excitation and emission work (e.g., Johnson et al., Malone et al., Young et al. and references therein). Recently, we have focused on the near-threshold-to-peak region of N2 with the goal of providing low energy collision parameters of the X1?g+ and E3?g+ transitions for modeling auroral and dayglow phenomena in these N2-rich atmospheres. The Lyman-Birge-Hopfield (LBH) emissions, from A3?u+ transitions, are `bellwether' measurements for diurnal Terrestrial Space Weather variations. However, near-threshold cross section data is still lacking for the a1?g state, as well as the `slow-cascade' a'1?u- and w1?u contributors to LBH emissions. In addition, Vegard-Kaplan (VK) emissions, from the B3?g transitions, recently observed in Titan's thermosphere, require further improved monoenergetic laboratory measurements. New electron energy-loss measurements, along with direct excitation (integral) cross sections, are presented for excitation of the lower states of N2, with finely-spaced impact energy increments in the threshold-to-peak region. Our recent work, including vibrationally resolved excitation, addresses these atmospheric data needs. Support from NASA's PATM, NSF-RUI, and NSF-Aeronomy programs are gratefully acknowledged.

  18. Conceptual Framework to Enable Early Warning of Relevant Phenomena (Emerging Phenomena and Big Data)

    SciTech Connect

    Schlicher, Bob G; Abercrombie, Robert K; Hively, Lee M

    2013-01-01

    Graphs are commonly used to represent natural and man-made dynamic systems such as food webs, economic and social networks, gene regulation, and the internet. We describe a conceptual framework to enable early warning of relevant phenomena that is based on an artificial time-based, evolving network graph that can give rise to one or more recognizable structures. We propose to quantify the dynamics using the method of delays through Takens Theorem to produce another graph we call the Phase Graph. The Phase Graph enables us to quantify changes of the system that form a topology in phase space. Our proposed method is unique because it is based on dynamic system analysis that incorporates Takens Theorem, Graph Theory, and Franzosi-Pettini (F-P) theorem about topology and phase transitions. The F-P Theorem states that the necessary condition for phase transition is a change in the topology. By detecting a change in the topology that we represent as a set of M-order Phase Graphs, we conclude a corresponding change in the phase of the system. The onset of this phase change enables early warning of emerging relevant phenomena.

  19. Intense phenomena during the winter of 1998/1999 in the northwestern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Hong, X.; Hodur, R. M.; Pascual, A.; Cummings, J. A.; Martin, P. J.

    2003-04-01

    The Northwestern Mediterranean Sea was characterized by intense weather and ocean phenomena during the winter of 1998/1999. This winter season exhibited very strong and prolonged periods of northwesterly winds (Mistral) with associated large losses of heat from the ocean due to enhanced surface buoyancy fluxes. Dense water formation occurred in the Gulf of Lion as the surface layer temperature dropped to 12 oC and the salinity increased to 38.2 psu. Hydrological and current data collected in 1999 revealed the spreading of newly formed deep water with unusual characteristics over the whole Algero-Provencal basin (Bethoux et al. 2002) and provided evidence of deep-water formation during the intense weather phenomenon. Sea surface topography from the TOPEX/Poseidon and ERS satellites, SST images derived from advanced very high resolution radiometer (AVHRR) sensors, and conductivity-temperature-depth (CTD) data collected during an oceanographic survey showed the presence of an intense anticyclonic eddy in the Balearic Sea from September 1998 to March 1999. The formation of this eddy is believed to be related to the transmission of anticyclonic vorticity from the shear of the strong Mistral (Pascual et al. 2002). To investigate these intense phenomena during the winter of 1998/1999, high-resolution (6-km) numerical simulations are conducted for the Mediterranean Sea using the US Navy Coastal Ocean Model (NCOM). The surface atmospheric forcing fields used in NCOM are from atmospheric reanalyses of the Mediterranean Sea area produced by the US Navy's Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPSTM). The reanalyzed fields include 10-m surface wind, surface wind stress, surface sensible and latent heat fluxes, solar and long-wave radiation at the surface, and accumulated precipitation. The temporal resolution of the atmospheric forcing fields is 1 hr and the horizontal resolution is 27 km. The simulations of these events are compared against all available observations. The mechanisms for the formation and development of the intense ocean phenomena during the winter of 1998/1999 are also investigated and discussed with sensitivity experiments under different atmospheric forcing.

  20. Atmospheres of the Giant Planets

    NASA Technical Reports Server (NTRS)

    Ingersoll, Andrew P.

    2002-01-01

    The giant planets, Jupiter, Saturn, Uranus, and Neptune, are fluid objects. They have no solid surfaces because the light elements constituting them do not condense at solar-system temperatures. Instead, their deep atmospheres grade downward until the distinction between gas and liquid becomes meaningless. The preceding chapter delved into the hot, dark interiors of the Jovian planets. This one focuses on their atmospheres, especially the observable layers from the base of the clouds to the edge of space. These veneers arc only a few hundred kilometers thick, less than one percent of each planet's radius, but they exhibit an incredible variety of dynamic phenomena. The mixtures of elements in these outer layers resemble a cooled-down piece of the Sun. Clouds precipitate out of this gaseous soup in a variety of colors. The cloud patterns are organized by winds, which are powered by heat derived from sunlight (as on Earth) and by internal heat left over from planetary formation. Thus the atmospheres of the Jovian planets are distinctly different both compositionally and dynamically from those of the terrestrial planets. Such differences make them fascinating objects for study, providing clues about the origin and evolution of the planets and the formation of the solar system.

  1. The Jovian Atmospheres

    NASA Technical Reports Server (NTRS)

    Allison, Michael (Editor); Travis, Larry D. (Editor)

    1986-01-01

    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.

  2. Experiments to investigate direct containment heating phenomena with scaled models of the Surry Nuclear Power Plant

    SciTech Connect

    Blanchat, T.K.; Allen, M.D.; Pilch, M.M.; Nichols, R.T.

    1994-06-01

    The Containment Technology Test Facility (CTTF) and the Surtsey Test Facility at Sandia National Laboratories are used to perform scaled experiments that simulate High Pressure Melt Ejection accidents in a nuclear power plant (NPP). These experiments are designed to investigate the effects of direct containment heating (DCH) phenomena on the containment load. High-temperature, chemically reactive melt (thermite) is ejected by high-pressure steam into a scale model of a reactor cavity. Debris is entrained by the steam blowdown into a containment model where specific phenomena, such as the effect of subcompartment structures, prototypic air/steam/hydrogen atmospheres, and hydrogen generation and combustion, can be studied. Four Integral Effects Tests (IETs) have been performed with scale models of the Surry NPP to investigate DCH phenomena. The 1/61{sup th} scale Integral Effects Tests (IET-9, IET-10, and IET-11) were conducted in CTRF, which is a 1/6{sup th} scale model of the Surry reactor containment building (RCB). The 1/10{sup th} scale IET test (IET-12) was performed in the Surtsey vessel, which had been configured as a 1/10{sup th} scale Surry RCB. Scale models were constructed in each of the facilities of the Surry structures, including the reactor pressure vessel, reactor support skirt, control rod drive missile shield, biological shield wall, cavity, instrument tunnel, residual heat removal platform and heat exchangers, seal table room and seal table, operating deck, and crane wall. This report describes these experiments and gives the results.

  3. Individualization of the anisotropic phenomena of the imbalanced Nature

    NASA Astrophysics Data System (ADS)

    Shlafman, L. M.; Kontar, V. A.

    2013-05-01

    What is an individual phenomenon of Nature? Where are the boundaries? Why it is considered as an individual phenomenon? etc. People cannot directly detect the "something isotropic." Sometimes we notice that there is a "black box." But on closer inspection, especially with new methods, the "black box" began to lighten. It seems that his "blackness" is the result of imperfect human sensors and interpretations, but not a phenomenon of Nature. Really people can identify only the anisotropic phenomena of Nature, but with the significant errors. Let's take a look at our home planet Earth. Where are the borders of our planet? It is may seem as the very simple question. People walk on the land and swim on the seas. This is the border on the surface of land and water. But what is about the dust? The dust is a part of the land, which is in the air. Weight of dust is very small compared to the weight of the planet. But it is the dust has formed valleys. Dust can rise very high above the planet's surface and even fly into the space. A similar situation is with the water. The bulk of the liquid water is in surface and underground waters. Water vapor is in the atmosphere. Atmospheric water is much less than on the earth and under the earth. But atmospheric water plays a huge role in the world and even extends into the space. Without a full accounting of dust and water impossible correctly describe the planet. But with considering the dust and water the planet is not solid-liquid ball. It is like "fuzzy blowball" with the boundaries that go to infinity. This "fuzziness" refers to gravity. The gravitational field does not end in the Lagrange points. This "fuzziness" illustrated by the electro-magnetic fields, etc. Our planet can be seen as a multidimensional anisotropic phenomenon of Nature. The anisotropy precisely is, and therefore is the gradient and movement. This phenomenon is clearly imbalanced because nothing ever repeats itself exactly, etc. The borders of any anisotropic imbalanced natural phenomenon can be determined with the precision which allow the sensors and methods of interpretation. The desire to identify the separate object in the imbalanced continuous Nature is the consequence of personalized thinking of people. In Nature is not exists any separate and independent phenomenon. In Nature are exist only the more or less concentrated anisotropy, which are constantly changing in the infinite continuity. Some references: Vladimir A Kontar, Federal GEOS Funding, US: 1. What is Imbalance of Nature? 2. What is the Imbalance of Water in Nature? 3. The Imbalance of Water in Nature as System 4. Axiomatic of the Imbalance of Nature and the Imbalance of Water in Nature 5. Water Management on the Verge of the Imbalanced Revolution 6. Control the Imbalance in Nature for Humanity Survival 7. Proof of the Imbalance of Nature in the Universe 8. Imbalanced Logic as the next level development of science Vladimir A. Kontar, Lyubov M. Shlafman, Federal GEOS Funding, US: 1. The relativity theory of the imbalance of water in nature 2. Redeployment as a Parameter to Measure the Imbalance of Water in Nature 4. Imbalance's Hypothesis for the Origin and Dynamics of Water on the Terrestrial Planets 5. Imbalance of Water and Carbon as Factors of the Global Climate Changes

  4. Certain relativistic phenomena in crystal optics

    NASA Astrophysics Data System (ADS)

    Chee-Seng, Lim

    1980-01-01

    Relativistic unsteady phenomena are established for a crystalline medium with unaligned sets of permittivity and permeability principal axes, but incorporating a compounded uniaxiality about some nonprincipal direction. All effects originate from a suddenly activated, arbitrarily oriented, maintained line current conducted with a finite velocity v. Integral representations studied in another paper (Chee-Seng) are applied. The original coordinate system is subjected to a series of rotational and translational, scaled and unscaled transformations. No specific coordinate frame is strictly adhered to. Instead, it is often expedient and advantageous to exploit several reference frames simultaneously in the course of the analysis and interpretations. The electric field is directly related to a net scalar field ? involving another scalar ? and its complement ? which can be deduced from ?; ? and ? are associated with two expanding, inclined ellipsoidal wavefronts ? and ?; these are cocentered at the current origin and touch each other twice along the uniaxis. Elsewhere, ? leads ?. For a source current faster than ?:vt ? ext?, ??0 within a finite but growing ''ice-cream cone'' domain, its nontrivial composition being ?-1/2 inside ? and 2?-1/2 inside part of a tangent cone from the advancing current edge vt to, and terminating at, ?; the function ? vanishes along such a tangent cone. Alternatively, for a source current slower than ?:vt? int?, if vt is avoided, ??0 everywhere, while ?=?-1/2 inside ? but vanishes identically outside ?. However, the crucial scalar field ? depends on three separate current-velocity regimes. Over a slow regime: vt? int?, ? is nontrivial inside ? wherein it is discontinuous across ?. Over an intermediate regime: vt ? int? ext?, ? takes four distinct forms on 12 adjacent domains bounded by ?, ? and a double-conical tangent surface linking vt to ?. But for a fast regime: vt? ext?, ? assumes six distinct forms on 18 adjacent domains bounded by ?, ? plus two double-conical tangent surfaces, convertexed at vt, to both ? and ?. Singularities are normally confined to these boundaries. Relative to a moving frame, ? is time-independent. Nevertheless, ? and, consequently, ? evolve unsteadily, principally because of transitions across the expanding ellipsoids ? and ? which also acquire a relative retreat from the current edge vt. An evolution scheme is discussed in detail. This produces, among other things, a steady state corollary which, in turn, covers ?erenkov radiation. A quadrical symmetry exists with respect to a family {Q?} of constant ?-surfaces. These are quadric surfaces cocentered at vt and having principal axes inclined to those of ? (and ?). Their interactions with ? are closely examined. If vt ? ext?, each Q? is a hyperboloid of two sheets which are asymptotic to the double-conical tangent surface connecting ? to vt; ? can become nontrivial on only one sheet, viz., that which is approached by ? as the latter retreats from vt; eventually, two permanent intersections, one following the other, occur along two expanding and travelling parallel plane circuits. But if vt ? int?, each Q? is an ellipsoid inside which ? initially evolves until an encounter occurs, first as a point contact which immediately grows into a plane circuit; as this traverses Q?, it expands and then contracts to a diametrically opposite point where contact breaks off. Finally, an elliptical axisymmetry about a principal direction of {Q?} is demonstrated. Corresponding behaviors hold in relation to ?.

  5. Seepage phenomena on Mars at subzero temperature

    NASA Astrophysics Data System (ADS)

    Kereszturi, Akos; Möhlmann, Diedrich; Berczi, Szaniszlo; Ganti, Tibor; Horvath, Andras; Kuti, Adrienn; Pocs, Tamas; Sik, Andras; Szathmary, Eors

    At the southern hemisphere of Mars seasonal slope structures emanating from Dark Dune Spots are visible on MGS MOC, and MRO HiRISE images. Based on their analysis two groups of streaks could be identified: diffuse and fan shaped ones forming in an earlier phase of local spring, probably by CO2 gas jets, and confined streaks forming only on steep slopes during a later seasonal phase. The dark color of the streaks may arise from the dark color of the dune grains where surface frost disappeared above them, or caused by the phase change of the water ice to liquid-like water, or even it may be influenced by the solutes of salts in the undercooled interfacial water The second group's morphology (meandering style, ponds at their end), morphometry, and related theoretical modelling suggest they may form by undercooled water that remains in liquid phase in a thin layer around solid grains. We analyzed sequence of images, temperature and topographic data of Russel (54S 12E), Richardson (72S 180E) and an unnamed crater (68S 2E) during southern spring. The dark streaks here show slow motion, with an average speed of meter/day, when the maximal daytime temperature is between 190 and 220 K. Based on thermophysical considerations a thin layer of interfacial water is inevitable on mineral surfaces under the present conditions of Mars. With 10 precipitable micrometer of atmospheric water vapor, liquid phase can be present down about 190 K. Under such conditions dark streaks may form by the movement of grains lubricatred by interfacial water. This possibility have various consequences on chemical, mechanical or even possible astrobiological processes on Mars. Acknowledgment: This work was supported by the ESA ECS-project No. 98004 and the Pro Renovanda Cultura Hungariae Foundation.

  6. Synchro-ballistic recording of detonation phenomena

    SciTech Connect

    Critchfield, R.R.; Asay, B.W.; Bdzil, J.B.; Davis, W.C.; Ferm, E.N.; Idar, D.J.

    1997-09-01

    Synchro-ballistic use of rotating-mirror streak cameras allows for detailed recording of high-speed events of known velocity and direction. After an introduction to the synchro-ballistic technique, this paper details two diverse applications of the technique as applied in the field of high-explosives research. In the first series of experiments detonation-front shape is recorded as the arriving detonation shock wave tilts an obliquely mounted mirror, causing reflected light to be deflected from the imaging lens. These tests were conducted for the purpose of calibrating and confirming the asymptotic Detonation Shock Dynamics (DSD) theory of Bdzil and Stewart. The phase velocities of the events range from ten to thirty millimeters per microsecond. Optical magnification is set for optimal use of the film`s spatial dimension and the phase velocity is adjusted to provide synchronization at the camera`s maximum writing speed. Initial calibration of the technique is undertaken using a cylindrical HE geometry over a range of charge diameters and of sufficient length-to-diameter ratio to insure a stable detonation wave. The final experiment utilizes an arc-shaped explosive charge, resulting in an asymmetric detonation-front record. The second series of experiments consists of photographing a shaped-charge jet having a velocity range of two to nine millimeters per microsecond. To accommodate the range of velocities it is necessary to fire several tests, each synchronized to a different section of the jet. The experimental apparatus consists of a vacuum chamber to preclude atmospheric ablation of the jet tip with shocked-argon back lighting to produce a shadow-graph image.

  7. Meteorological phenomena affecting the presence of solid particles suspended in the air during winter

    NASA Astrophysics Data System (ADS)

    Cariñanos, P.; Galán, C.; Alcázar, P.; Dominguez, E.

    Winter is not traditionally considered to be a risky season for people who suffer from pollen allergies. However, increasing numbers of people are showing symptoms in winter. This prompted our investigation into the levels of solid material in the air, and some of the meteorological phenomena that allow their accumulation. This study showed a possible relationship between the phenomenon of thermal inversion, which occurs when very low temperatures, cloudless skies and atmospheric calms coincide, and an increase in the concentration of solid material in the atmosphere. Frequently, this situation is associated with other predictable phenomena such as fog, dew and frost. This may allow a warning system to be derived for urban pollution episodes. The effect caused by parameters such as wind and rainfall was also analysed. Solid material was differentiated into non-biological material from natural and non-natural sources (e.g. soot, dust, sand, diesel exhaust particles, partially burnt residues) and biological material. The latter mainly comprises pollen grains and fungal spores. Owing to its abundance and importance as a causal agent of winter allergies, Cupressaceae pollen was considered separately.

  8. Laboratory experiments in atmospheric optics

    NASA Astrophysics Data System (ADS)

    Vollmer, Michael; Tammer, Robert

    1999-08-01

    Old and new laboratory experiments on atmospheric optics with a focus on mirages, rainbows, and halos are presented. Some qualitative demonstrations serve primarily didactical purposes, e.g., by proving the existence of curved light rays in media with a gradient of the index of refraction, by directly visualizing the minimum-deviation curve for rainbow paths in water droplets, or by helping to elucidate the ray classes in hexagons that contribute to a specific halo. In addition, quantitative experiments allow a direct comparison of angular positions and intensities with analytical computations or Monte Carlo simulations of light scattering from small water droplets or ice hexagons. In particular, the latter can help us to understand complex halo phenomena.

  9. Laboratory Experiments in Atmospheric Optics

    NASA Astrophysics Data System (ADS)

    Vollmer, Michael; Tammer, Robert

    1998-03-01

    Old and new laboratory experiments on atmospheric optics with a focus on mirages, rainbows, and halos are presented. Some qualitative demonstrations serve primarily didactical purposes, e.g., by proving the existence of curved light rays in media with a gradient of the index of refraction, by directly visualizing the minimum-deviation curve for rainbow paths in water droplets, or by helping to elucidate the ray classes in hexagons that contribute to a specific halo. In addition, quantitative experiments allow a direct comparison of angular positions and intensities with analytical computations or Monte Carlo simulations of light scattering from small water droplets or ice hexagons. In particular, the latter can help us to understand complex halo phenomena.

  10. Investigations of atmospheric dynamics using a CW Doppler sounder array

    NASA Technical Reports Server (NTRS)

    Rao, G. L.

    1974-01-01

    A three-dimensional CW Doppler sounding system currently under operation at the NASA-Marshall Space Flight Center, Alabama is described. The properties of the neutral atmosphere are discussed along with the theory of Doppler sounding technique. Methods of data analyses used to investigate the dynamical phenomena at the ionospheric heights are presented and suggestions for future investigations provided.

  11. Numerical simulation of anomalous wave phenomena in hot nuclear matter

    NASA Astrophysics Data System (ADS)

    Konyukhov, A. V.; Likhachev, A. P.

    2015-11-01

    The collective dynamic phenomena accompanying the collision of high-energy heavy ions are suggested to be approximately described in the framework of ideal relativistic hydrodynamics. If the transition from hadron state to quark-gluon plasma is the first-order phase transition (presently this view is prevailing), the hydrodynamic description of the nuclear matter must demonstrate several anomalous wave phenomenasuch as the shock splitting and the formation of rarefaction shock and composite waves, which may be indicative of this transition. The present work is devoted to numerical study of these phenomena.

  12. Realistic generation of natural phenomena based on video synthesis

    NASA Astrophysics Data System (ADS)

    Wang, Changbo; Quan, Hongyan; Li, Chenhui; Xiao, Zhao; Chen, Xiao; Li, Peng; Shen, Liuwei

    2009-10-01

    Research on the generation of natural phenomena has many applications in special effects of movie, battlefield simulation and virtual reality, etc. Based on video synthesis technique, a new approach is proposed for the synthesis of natural phenomena, including flowing water and fire flame. From the fire and flow video, the seamless video of arbitrary length is generated. Then, the interaction between wind and fire flame is achieved through the skeleton of flame. Later, the flow is also synthesized by extending the video textures using an edge resample method. Finally, we can integrate the synthesized natural phenomena into a virtual scene.

  13. Analytical investigation of critical phenomena in MHD power generators

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Critical phenomena in the Arnold Engineering Development Center (AEDC) High Performance Demonstration Experiment (HPDE) and the U.S. U-25 Experiment, are analyzed. The performance of a NASA specified 500 MW(th) flow train is analyzed. Critical phenomena analyzed include: Hall voltage overshoots; optimal load schedules; parametric dependence of the electrode voltage drops; boundary layer behavior; near electrode phenomena with finite electrode segmentation; current distribution in the end regions; scale up rules; optimum Mach number distribution; and the effects of alternative cross sectional shapes.

  14. Data Processing for Atmospheric Phase Interferometers

    NASA Technical Reports Server (NTRS)

    Acosta, Roberto J.; Nessel, James A.; Morabito, David D.

    2009-01-01

    This paper presents a detailed discussion of calibration procedures used to analyze data recorded from a two-element atmospheric phase interferometer (API) deployed at Goldstone, California. In addition, we describe the data products derived from those measurements that can be used for site intercomparison and atmospheric modeling. Simulated data is used to demonstrate the effectiveness of the proposed algorithm and as a means for validating our procedure. A study of the effect of block size filtering is presented to justify our process for isolating atmospheric fluctuation phenomena from other system-induced effects (e.g., satellite motion, thermal drift). A simulated 24 hr interferometer phase data time series is analyzed to illustrate the step-by-step calibration procedure and desired data products.

  15. Lithosphere - Atmosphere - Ionosphere Circuit Model

    NASA Astrophysics Data System (ADS)

    Kereselidze, Z.; Kachakhidze, N.; Kachakhidze, M.

    2012-04-01

    There are offered possibilities of original LAI circuit model. The problem concerns of existence of self-generated electromagnetic oscillations in the segment of LAI system, which are results of tectonic stress developing in the focus area of expected earthquake. By this model the main (lowest) frequency of these electromagnetic oscillations frequency spectrum is expressed analytically by following formula: ? = ? c l where ?(?) is the coefficient depended on the frequency and geological characteristics of the medium and approximate to one, c-is the speed of light, and l- the length of the fault in the focus of the expected earthquake. On the base of relevant diagnosis of experimental data, the model gives us possibility to discuss the problem about location, time of occurrence and intensity of an expected earthquake with certain accuracy. In addition to it, considered model does not block the fall-unstable model of earthquake preparing and electromagnetic phenomena accompanied earthquake preparing process. On the contrary, the imagination of physical picture may be simplified in the separate stage of earthquakes preparing. Namely, it is possible to reliably separate series of foreshocks and aftershocks. By this point of view, the certain optimism about using of EM emission as earthquake precursor of full value may be expressed. The base of such optimism is developing of various phenomena connected to VLF emission many times fixed in the surroundings of epicentral area and cosmic space (changing of intensity of electro-telluric current, perturbations of geomagnetic field in forms of irregular pulsations or regular short-period pulsations, perturbations of atmospheric electric field, perturbations of ionosphere critical frequency and TEC, variations of height of lower ionosphere, parameters of ionospheric medium: changing of specific dielectric conductivity and spectrum of MGD waves in it, atmospheric-ionospheric discharging and etc.).

  16. ldentifying Episodes of Earth Science Phenomena Using a Big-Data Technology

    NASA Technical Reports Server (NTRS)

    Kuo, Kwo-Sen; Oloso, Amidu; Rushing, John; Lin, Amy; Fekete, Gyorgy; Ramachandran, Rahul; Clune, Thomas; Dunny, Daniel

    2014-01-01

    A significant portion of Earth Science investigations is phenomenon- (or event-) based, such as the studies of Rossby waves, volcano eruptions, tsunamis, mesoscale convective systems, and tropical cyclones. However, except for a few high-impact phenomena, e.g. tropical cyclones, comprehensive records are absent for the occurrences or events of these phenomena. Phenomenon-based studies therefore often focus on a few prominent cases while the lesser ones are overlooked. Without an automated means to gather the events, comprehensive investigation of a phenomenon is at least time-consuming if not impossible. We have constructed a prototype Automated Event Service (AES) system that is used to methodically mine custom-defined events in the reanalysis data sets of atmospheric general circulation models. Our AES will enable researchers to specify their custom, numeric event criteria using a user-friendly web interface to search the reanalysis data sets. Moreover, we have included a social component to enable dynamic formation of collaboration groups for researchers to cooperate on event definitions of common interest and for the analysis of these events. An Earth Science event (ES event) is defined here as an episode of an Earth Science phenomenon (ES phenomenon). A cumulus cloud, a thunderstorm shower, a rogue wave, a tornado, an earthquake, a tsunami, a hurricane, or an El Nino, is each an episode of a named ES phenomenon, and, from the small and insignificant to the large and potent, all are examples of ES events. An ES event has a duration (often finite) and an associated geo-location as a function of time; it's therefore an entity embedded in four-dimensional (4D) spatiotemporal space. Earth Science phenomena with the potential to cause massive economic disruption or loss of life often rivet the attention of researchers. But, broader scientific curiosity also drives the study of phenomena that pose no immediate danger, such as land/sea breezes. Due to Earth System's intricate dynamics, we are continuously discovering novel ES phenomena. We generally gain understanding of a given phenomenon by observing and studying individual events. This process usually begins by identifying the occurrences of these events. Once representative events are identified or found, we must locate associated observed or simulated data prior to commencing analysis and concerted studies of the phenomenon. Knowledge concerning the phenomenon can accumulate only after analysis has started. However, as mentioned previously, comprehensive records only exist for a very limited set of high-impact phenomena; aside from these, finding events and locating associated data currently may take a prohibitive amount of time and effort on the part of an individual investigator. The reason for the lack of comprehensive records for most of the ES phenomena is mainly due to the perception that they do not pose immediate and/or severe threat to life and property. Thus they are not consistently tracked, monitored, and catalogued. Many phenomena even lack precise and/or commonly accepted criteria for definitions. Moreover, various Earth Science observations and data have accumulated to a previously unfathomable volume; NASA Earth Observing System Data Information System (EOSDIS) alone archives several petabytes (PB) of satellite remote sensing data, which are steadily increasing. All of these factors contribute to the difficulty of methodically identifying events corresponding to a given phenomenon and significantly impede systematic investigations. We have not only envisioned AES as an environment for identifying customdefined events but also aspired for it to be an interactive environment with quick turnaround time for revisions of query criteria and results, as well as a collaborative environment where geographically distributed experts may work together on the same phenomena. A Big Data technology is thus required for the realization of such a system. In the following, we first introduce the technology selected for AES in the next section. We then demonstrate the utility of AES using a use case, Blizzard, before we conclude.

  17. INVESTIGATION INTO BIOFOULING PHENOMENA IN FINE PORE AERATION DEVICES

    EPA Science Inventory

    Microbiologically-based procedures were used to describe biofouling phenomena on fine pore aeration devices and to determine whether biofilm characteristics could be related to diffuser process performance parameters. ine pore diffusers were obtained from five municipal wastewate...

  18. INVESTIGATIONS INTO BIOFOULING PHENOMENA IN FINE PORE AERATION DEVICES

    EPA Science Inventory

    Microbiologically-based procedures were used to describe biofouling phenomena on fine pore aeration devices and to determine whether biofilm characteristics could be related to diffuser process performance parameters. Fine pore diffusers were obtained from five municipal wastewa...

  19. Probing Cytological and Reproductive Phenomena by Means of Bryophytes.

    ERIC Educational Resources Information Center

    Newton, M. E.

    1985-01-01

    Describes procedures (recommended for both secondary and college levels) to study mitosis, Giemsa C-banding, reproductive phenomena (including alternation of generations), and phototropism in mosses and liverworts. (JN)

  20. Microbiology and atmospheric processes: research challenges concerning the impact of airborne micro-organisms on the atmosphere and climate

    NASA Astrophysics Data System (ADS)

    Morris, C. E.; Sands, D. C.; Bardin, M.; Jaenicke, R.; Vogel, B.; Leyronas, C.; Ariya, P. A.; Psenner, R.

    2011-01-01

    For the past 200 years, the field of aerobiology has explored the abundance, diversity, survival and transport of micro-organisms in the atmosphere. Micro-organisms have been explored as passive and severely stressed riders of atmospheric transport systems. Recently, an interest in the active roles of these micro-organisms has emerged along with proposals that the atmosphere is a global biome for microbial metabolic activity and perhaps even multiplication. As part of a series of papers on the sources, distribution and roles in atmospheric processes of biological particles in the atmosphere, here we describe the pertinence of questions relating to the potential roles that air-borne micro-organisms might play in meteorological phenomena. For the upcoming era of research on the role of air-borne micro-organisms in meteorological phenomena, one important challenge is to go beyond descriptions of abundance of micro-organisms in the atmosphere toward an understanding of their dynamics in terms of both biological and physico-chemical properties and of the relevant transport processes at different scales. Another challenge is to develop this understanding under contexts pertinent to their potential role in processes related to atmospheric chemistry, the formation of clouds, precipitation and radiative forcing. This will require truly interdisciplinary approaches involving collaborators from the biological and physical sciences, from disciplines as disparate as agronomy, microbial genetics and atmosphere physics, for example.

  1. Department of Energy Natural Phenomena Hazards Mitigation Program

    SciTech Connect

    Murray, R.C.

    1993-09-01

    This paper will present a summary of past and present accomplishments of the Natural Phenomena Hazards Program that has been ongoing at Lawrence Livermore National Laboratory since 1975. The Natural Phenomena covered includes earthquake; winds, hurricanes, and tornadoes; flooding and precipitation; lightning; and volcanic events. The work is organized into four major areas (1) Policy, requirements, standards, and guidance (2) Technical support, research development, (3) Technology transfer, and (4) Oversight.

  2. Deep Inelastic Scattering and Related Phenomena

    NASA Astrophysics Data System (ADS)

    D'Agostini, G.; Nigro, A.

    1997-03-01

    The Table of Contents for the book is as follows: * Organization * Foreword * Welcome Address * PLENARY SESSION: "From Paris to Rome" * Deep Inelastic Physics with H1 * Recent Results from ZEUS * Overview of the Status of Polarised Structure Functions * Quarks and Gluons at Hadron Colliders * Deep Inelastic Scattering - Theory and Phenomenology * WORKING GROUP 1: Structure Functions * Inclusive Jet Cross Section Measurement at CDF * Measurement of Direct Photons by the DØ Experiment * MRS Parton Distributions * Global QCD Analysis, the Gluon Distribution, and High Et Inclusive Jet Data * F2 Measurement and QCD Analysis on 94 H1 Data * The ZEUS 1994 F2 Measurement * Measurement of the Total γ*p Cross Section at very Low x and Q2 at HERA * New Results on F2 Structure Functions * Proton Structure Function and Gluon Distribution Functions from Fermilab Experiment E665 * The Transition from the Photoproduction to the DIS Region * The BFKL Pomeron: Can It Be Detected? * BFKL/CCFM Phenomenology * Physics and Mathematics of Dynamical Partons * k⊥-Factorization and Perturbative Invariants at Small x * Double Scaling Violations * On the Asymptotic Behaviour of F2(x, Q2) * Double Logarithmic Scaling of F2 * Differential Charged Current Cross-Sections at HERA * Neutral Current ep Deep Inelastic Scattering at High Q2 and Limits on New Physics * Charm Production in Charged-Current DIS and Extraction of the Strange Sea Density * Extraction of the Gluon Density * On Problems in Extracting the Gluon Density from the Nucleon Structure Function Measurements * Inclusive Measurement of the Strong Coupling at HERA * A Measurement of R = σL/σT in Deep Inelastic Neutrino-Nucleon Scattering at the Tevatron * A Measurement of R = σL/σT in Deep Inelastic μ - p and μ - d Scattering * A Determination of the Longitudinal Proton Structure Function FL(x, Q2) at Low x at HERA * Prospects for Measuring R = σL/σT at HERA in 1966 Low-Energy Running * A Leading Order, in ln(1/x) as well as αs(Q2), Calculation of Structure Functions * The Longitudinal Structure Function FL at Small x * Hard Diffractive Scattering: Partons and QCD * Diffractive Factorization - A Simple Field Theory Model for Fdiff2 (βxℙ, Q2; xℙ, t) * Proton Structure Functions in the Dipole Picture of BFKL Dynamics * DIS Diffractive Dissociation * Constraining the Proton's Gluon Density by Inclusive Charm Electroproduction at HERA * D*(2010) Production in Deep Inelastic Scattering at HERA * First Results on Open Charm Production in Deep Inelastic Scattering from H1 * WORKING GROUP 2: Photoproduction * Tagged Dilepton Production in γγ Interactions at LEP with the L3 Detector * Jets at Low Q2 and Virtual Photon Structure * Direct and Resolved Photoproduction at HERA with Virtual and Quasi-Real Photons * Isolated Prompt Photon Production at HERA * Observation of Isolated High-ET Photons in Hard Photoproduction at HERA * Photoproduction of Jets at HERA * Recent ZEUS Results on Dijet Cross-sections in Photoproduction at HERA * Multiple Parton Interactions and Initial State Parton Radiation in Photoproduction * Inclusive Hadron Production in ee and ep Collisions * Inclusive Charged Particle Spectra in Photoproduction at H1 * K0 Production in γp Interactions at HERA * The Transverse Momentum Evolution of the W2 Dependence of Inclusive Charged Particle Photoproduction at HERA * Heavy Quarks Photoproduction * Photoproduction of D*± Mesons in Electron-Proton Collisions at HERA * D* Photoproduction at HERA * Some Comments on the Photoproduction of Charm * J/ψ Production at HERA * Heavy Quark and Quarkonium Photoproduction in the Semi-Hard Approach of QCD at HERA * WORKING GROUP 3: Diffraction * The Soft Pomeron * Inclusive Measurements of Diffraction in Deep-Inelastic Scattering and Photoproduction at HERA * Measurement of the Diffractive Cross-Section in Deep Inelastic Scattering * Deep Inelastic Diffractive Results with the ZEUS Leading Proton Spectrometer * Diffractive DIS from the Color Dipole BFKL pomeron * Recent Results on Diffractive Scattering in Muon-Proton Interactions from the E665 Experiment * Jets in Diffractive ep Interactions * Energy Flow and Open Charm Production in Diffractive Deep Inelastic Scattering * Photoproduction of ρ0, ω and ∫ Mesons at ZEUS * Diffractive Photoproduction of ρ and ∫ at Large |t| * Photoproduction of Vector Mesons at H1 * Vector Meson Production at High Q2 * Diffractive Production of coverline c Systems at HERA * Diffractive Light Vector Meson Production at Large Momentum Transfer * Observation of High Energy Forward Neutrons in Deep Inelastic Scattering at HERA * Diffractive Hard Scattering - Report from the HERA Workshop * Monte Carlo Generators for Diffractive Processes * Thrust Jet Analysis of Diffractive Deep Inelastic Scattering Events at HERA * Diffractive Deep Inelastic Scattering with a Logarithmic Pomeron Trajectory * Odd C Parity Effects in Diffraction * Fracture Functions * WORKING GROUP 4: Final States * Confronting QCD Models with DIS Events at HERA * The Measurement of Fragmentation Functions in the Breit Frame * Thrust Analysis in Deep Inelastic Scattering * NLO Corrections to Jet Cross-sections in DIS * Measurement of αs from Jet Rates in Deep Inelastic Scattering at HERA * Dijet Production in Neutral Current Deep Inelastic Scattering and Determination of the Gluon Density * A Direct Determination of αs (Q2) and fg/p (ξ, Q2) in Next-to-leading-order from (2+1)-jet Rates in the H1-Experiment * A Measurement of αs from Differential Jet Rates * QCD Jet Calculations in DIS Based on the Subtraction Method and Dipole Formalism * Jet Production at DØ * Rapidity Gaps in Hard Photoproduction with ZEUS * Diffraction in Charged Current DIS * Diquark Jets in DIS Diffraction Dissociation * Large Rapidity Gaps between Jets at HERA and at the Tevatron * Jet Production with Double Pomeron Exchange * Rapidity Gaps in Hard Processes at DØ * Onium Production * Tracing QCD-Instantons in Deep Inelastic Scattering * Instantons and Forward Jets at HERA * Forward Jets at HERA and at the Tevatron * Distinguishing the DGLAP and BFKL Evolutions with Transverse Momentum Spectra * The Properties of Hadrons in Neutrino-Neon Interactions * Transverse Energy Flow Distributions in Deep Inelastic Scattering at HERA * WORKING GROUP 5: Polarized Structure Functions * A New Measurement of the Spin Dependent Structure Functions gp1 and gd1 * Spin Asymmetry in Muon-deuteron Deep Inelastic Scattering on a Transversely Polarized Target * Polarization of Valence and Light Sea Quarks in the Nucleon * Results from SLAC * Inclusive Spin-Dependent DIS from the Nucleon with HERMES * Semi-Inclusive Data from HERMES * Future Measurements of the g1 Spin Structure function with Polarized e - p Collisions and Determination of Δg * A Future Measurement of ΔG at CERN * The Polarized Two-Loop Splitting Functions * Polarized Parton Distributions from a Global NLO-QCD Analysis * Polarized Partons at Next-to-leading Order * Small-x Behaviour of the Structure Function g1 * On Small-x Resummations for the Evolution of Unpolarized and Polarized Non-Singlet and singlet Structure Functions * Parton Model Prediction for g2 * On the Twist-2 Contributions to Polarized Structure Functions and New Sum Rules * Some Aspects of the Polarized Structure Functions * Inclusive Production of Hadrons in l↑p↑ → h↑X and Spin Measurements * Polarized Structure Functions and QPMSR * Polarization Phenomena and Photon Dissociation in Deep-Inelastic Lepton-Nucleon Scattering * Prospects for Measuring Δg from Jets at HERA with Polarized Protons * On the Q2 Dependence of Asymmetry A1 * WORKING GROUP 6: Special Theoretical Topics * Coherence and Final States in DIS at Small x * Unitarity and Saturation in the Dipole Formulation * Radiative Corrections to the Leading log(1/x) Approximation for Structure Functions * Effective Action Approach for Small-x Physics in QCD * Unitarization of BFKL Pomeron * The Role of the Running Coupling in DIS and Some Very Peculiar Events * Pion Structure Functions in a Constituent Model * Fixed Points and Power Corrections * Unitarity, Regge Poles and R.G. in DIS * Hadronic Production of Heavy Mesons in Perturbative QCD * Soft Pomeron Physics on the Lattice * Lattice DIS Structure Functions * PLENARY SESSION: Reports from Working Groups * Structure Functions * Summary of Working Group 2: Photoproduction * Diffractive Interactions * Summary of Special Theoretical Session * Hadronic Final States * The Spin Structure of Nucleons. Prospects to Measure the Gluon Polarization ΔG * Spin Effects in Lepton-Nucleon Scattering: A Theoretical Overview * Summary * List of Participants

  3. Light flash phenomena induced by HzE particles

    NASA Technical Reports Server (NTRS)

    Mcnulty, P. J.; Pease, V. P.

    1980-01-01

    Astronauts and Apollo and Skylab missions have reported observing a variety of visual phenomena when their eyes are closed and adapted to darkness. These phenomena have been collectively labelled as light flashes. Visual phenomena which are similar in appearance to those observed in space have been demonstrated at the number of accelerator facilities by expressing the eyes of human subjects to beams of various types of radiation. In some laboratory experiments Cerenkov radiation was found to be the basis for the flashes observed while in other experiments Cerenkov radiation could apparently be ruled out. Experiments that differentiate between Cerenkov radiation and other possible mechanisms for inducing visual phenomena was then compared. The phenomena obtained in the presence and absence of Cerenkov radiation were designed and conducted. A new mechanism proposed to explain the visual phenomena observed by Skylab astronauts as they passed through the South Atlantic Anomaly, namely nuclear interactions in and near the sensitive layer of the retina, is covered. Also some studies to search for similar transient effects of space radiation on sensors and microcomputer memories are described.

  4. Encoding continuous spatial phenomena in GML

    NASA Astrophysics Data System (ADS)

    de Vries, M. E.; Ledoux, H.

    2009-04-01

    In the discussion about how to model and encode geographic information two meta-models of space exist: the 'object' view and the 'field' view. This difference in conceptual view is also reflected in different data models and encoding formats. Among GIS practitioners, fields' (or coverages') are being used almost exclusively in 2D, while in the geoscience community 3D and higher-dimensional fields are widely used. (Note that the dimensions in oceanographic/atmospheric coverages are not necessarily spatial dimensions, as any parameters (e.g. temperature of the air, or density of water) can be considered a dimension.) While standardisation work in ISO and OGC has led to agreement on how to best encode discrete spatial objects, for the modelling and encoding of continuous fields' there are still a number of open issues. In the presentation we will shortly discuss the current standards related to fields, and look at their shortcomings and potential. In ISO 19123 for example a distinction is made between discrete and continuous coverages, but the difference is not very clear and hard to capture for implementers. As far as encoding is concerned: GML 3.x (ISO 19136) has a discrete coverage data type, but no continuous coverage type. We will then present an alternative solution to model fields, and show how it can be implemented using some parts of GML, but not the ISO/GML coverage type. This alternative data model for fields permits us to represent fields in 2D and 3D, although conceptually it can be easily extended to higher dimensions. Unlike current standards where there is a distinction between discrete and continuous fields/coverages, we argue that a field should always have one - and only one! - value for a given attribute at every location in the spatial domain (be this domain the surface of the Earth, a 3D volume, or even a 4D spatio-temporal hypercube). The principal idea behind the proposed model is that two things are needed to have a coverage: 1. a set of samples of the phenomenon; 2. an interpolation function to reconstruct the continuity of the phenomenon studied. The samples can be any data that was collected to study the phenomenon: a set of scattered points in 2D or 3D; a set of lines (e.g. contour lines coming from a topographic map); a raster image coming from remote sensing or photogrammetry where the value of each pixel represents the temperature of the sea for instance; a triangulated irregular network or its counterpart in 3D; etc. For the interpolation function one must think of the usual interpolation methods (Piecewise, IDW, Kriging, NearestNeighbour, RST, GridInterpolation (Bilinear, Trilinear) etc.), but the list can easily be extended. The proposed conceptual model has the following advantages: - it respects the scientific definition of a field; - it is simple from a theoretical point of view, and thus easy to understand for users. A field is always something continuous; if you only have a dataset of scattered points, this is not a field. - it permits us to model every situation (and that in 2D and in 3D). Thus, no sub-types are necessary. - it uses types already defined in current implementation standards (i.e. GML). - it is extensible. Users can "plug" their own interpolation methods. - more importantly, it is more adapted than raster structures to the kind of datasets found in GIS related applications, because it permits us to always keep the original data that were collected to study a phenomenon, and simply generate new representations that are adapted to a particular use and application. - it is implementable. As a proof of concept a GML application schema was created, and some datasets were made as examples. We have called this prototype encoding language FieldGML, because as much as possible existing elements from the GML specification have been used (but not the coverage type itself). At the workshop we will go deeper into the 'why' and 'how' of the proposed conceptual model for fields, look at the implementation with parts of GML, and discuss how our approach fits in the broader picture: the relation with CSML, ncML-GML and WCS (response to a GetCoverage request), and - at the conceptual model side - the Common Data Model (Unidata, GALEON).

  5. Work on Planetary Atmospheres and Planetary Atmosphere Probes

    NASA Technical Reports Server (NTRS)

    Lester, Peter

    1999-01-01

    A summary final report of work accomplished is presented. Work was performed in the following areas: (1) Galileo Probe science analysis, (2) Galileo probe Atmosphere Structure Instrument, (3) Mars Pathfinder Atmosphere Structure/Meteorology instrument, (4) Mars Pathfinder data analysis, (5) Science Definition for future Mars missions, (6) Viking Lander data analysis, (7) winds in Mars atmosphere Venus atmospheric dynamics, (8) Pioneer Venus Probe data analysis, (9) Pioneer Venus anomaly analysis, (10) Discovery Venus Probe Titan probe instrument design, and (11) laboratory studies of Titan probe impact phenomena. The work has resulted in more than 10 articles published in archive journals, 2 encyclopedia articles, and many working papers. This final report is organized around the four planets on which there was activity, Jupiter, Mars, Venus, and Titan, with a closing section on Miscellaneous Activities. A major objective was to complete the fabrication, test, and evaluation of the atmosphere structure experiment on the Galileo probe, and to receive, analyze and interpret data received from the spacecraft. The instrument was launched on April 14, 1989. Calibration data were taken for all experiment sensors. The data were analyzed, fitted with algorithms, and summarized in a calibration report for use in analyzing and interpreting data returned from Jupiter's atmosphere. The sensors included were the primary science pressure, temperature and acceleration sensors, and the supporting engineering temperature sensors. Computer programs were written to decode the Experiment Data Record and convert the digital numbers to physical quantities, i.e., temperatures, pressures, and accelerations. The project office agreed to obtain telemetry of checkout data from the probe. Work to extend programs written for use on the Pioneer Venus project included: (1) massive heat shield ablation leading to important mass loss during entry; and (2) rapid planet rotation, which introduced terms of motion not needed on Venus. When the Galileo Probe encountered Jupiter, analysis and interpretation of data commenced. The early contributions of the experiment were to define (1) the basic structure of the deep atmosphere, (2) the stability of the atmosphere, (3) the upper atmospheric profiles of density, pressure, and temperature. The next major task in the Galileo Probe project was to refine, verify and extend the analysis of the data. It was the verified, and corrected data, which indicated a dry abiabatic atmosphere within measurement accuracy. Temperature in the thermosphere was measured at 900 K. Participation in the Mars atmospheric research included: (1) work as a team member of the Mars Atmosphere Working Group, (2) contribution to the Mars Exobiology Instrument workshop, (3) asssistance in planning the Mars global network and (4) assitance in planning the Soviet-French Mars mission in 1994. This included a return to the Viking Lander parachute data to refine and improve the definition of winds between 1.5 and 4 kilometer altitude at the two entry sites. The variability of the structure of Mars atmosphere was addressed, which is known to vary with season, latitude, hemisphere and dust loading of the atmosphere. This led to work on the Pathfinder project. The probe had a deployable meteorology mast that had three temperature sensors, and a wind sensor at the tip of the mast. Work on the Titan atmospheric probe was also accomplished. This included developing an experiment proposal to the European Space Agency (ESA), which was not selected. However, as an advisor in the design and preparation of the selected experiment the researcher interacted with scientist on the Huygens Probe Atmosphere Structure Experiment. The researcher also participated in the planning for the Venus Chemical Probe. The science objectives of the probe were to resolve unanswered questions concerning the minor species chemistry of Venus' atmosphere that control cloud formation, greenhouse effectiveness, and the thermal structure. The researcher also reviewed problems with the Pioneer Venus Probe, that caused anomalies which occurred on the Probes at and below 12.5 km level of the Venus' atmosphere. He convened and participated in a workshop that concluded the most likely hardware cause was insulation failure in the electrical harness outside the Probes' pressure vessels. It was discovered that the shrink tubing material failed at 600K. This failure could explain the anomalies experienced by the probes. The descent data of the Pioneer probes, and the Soviet Vega Lander was analyzed to evaluate the presence of small scale gravity waves in and below the Venus cloud layer.

  6. Atmospheric and Space Sciences: Neutral Atmospheres

    NASA Astrophysics Data System (ADS)

    Yi?it, Erdal

    2015-09-01

    The SpringerBriefs on Atmospheric and Space Sciences in two volumes presents a concise and interdisciplinary introduction to the basic theory, observation & modeling of atmospheric and ionospheric coupling processes on Earth. The goal is to contribute toward bridging the gap between meteorology, aeronomy, and planetary science. In addition recent progress in several related research topics, such atmospheric wave coupling and variability, is discussed. Volume 1 will focus on the atmosphere, while Volume 2 will present the ionosphere?? the plasma environment. Volume 1 is aimed primarily at (research) students and researchers that would like to gain quick insight in atmospheric sciences and current research. It also is a useful tool for professors who would like to develop a course in atmospheric physics.

  7. Rainbows, water droplets, and seeing--slow motion analysis of experiments in atmospheric optics.

    PubMed

    Vollmer, Michael; Möllmann, Klaus-Peter

    2011-10-01

    Many physics processes underlying phenomena in atmospheric optics happen on a rather short time scale such that neither the human eye nor video cameras are able to analyze the details. We report applications of high-speed imaging of laboratory experiments in atmospheric optics with subsequent slow motion analysis. The potential to study respective transient effects is investigated in general and for a few phenomena in detail, in particular for rainbow scattering due to single oscillating droplets during free fall, and for light propagation effects through atmospheric paths with turbulences, leading, e.g., to scintillation of stars or shimmering of mirage images. PMID:22016242

  8. Studies of extended planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Hunten, Donald M.

    1988-01-01

    Spectroscopic observations of gases and plasmas in the Jupiter system, and related phenomena such as the recently-discovered sodium atmospheres of Mercury and the Moon were made. Cunningham's work on Jupiter spectroscopy is complete. The optical thickness of the ammonia cloud increases from about 3 in the morning to 6 at sunset. This effect seems to be due to the combination of internal heat flow and a convective region heated at the top, giving strong convection at night and none during the day. Near-simultaneous methane data are of poor quality, but are consistent with this picture. Schneider's work on the sodium environment of Io is also complete. The eclipse data extend to nearly 10 Io radii and nicely match the densities in the outer regions (to 100 Io radii) obtained from the intensity scattered in the D lines. Other data show very fast jets of sodium (up to 100 km/sec), frequently tilted out of the orbital plane. Researchers seem to be seeing neutralized ions, not from the torus itself but from atmospheric sodium ionized and then quickly neutralized. The data set on Mercurian sodium has been augmented, and supplemented by IR reflectance spectra.

  9. Atmospheric corrosion of lithium electrodes

    SciTech Connect

    Johnson, C.J.

    1981-10-01

    Atmospheric corrosion of lithium during lithium-cell assembly and the dry storage of cells prior to electrolyte fill has been found to initiate lithium corrosion pits and to form corrosion products. Scanning Electron Microscopy (SEM) was used to investigate lithium pitting and the white floccullent corrosion products. Electron Spectroscopy for Chemical Analysis (ESCA) and Auger spectroscopy in combination with X-ray diffraction were used to characterize lithium surfaces. Lithium surfaces with corrosion products were found to be high in carbonate content indicating the presence of lithium carbonate. Lithium electrodes dry stored in unfilled batteries were found to contain high concentration of lithium flouride a possible corrosion product from gaseous materials from the carbon monofluoride cathode. Future investigations of the corrosion phenomena will emphasize the effect of the corrosion products on the electrolyte and ultimate battery performance. The need to protect lithium electrodes from atmospheric exposure is commonly recognized to minimize corrosion induced by reaction with water, oxygen, carbon dioxide or nitrogen (1). Manufacturing facilities customarily limit the relative humidity to less than two percent. Electrodes that have been manufactured for use in lithium cells are typically stored in dry-argon containers. In spite of these precautions, lithium has been found to corrode over a long time period due to residual gases or slow diffusion of the same into storage containers. The purpose of this investigation was to determine the nature of the lithium corrosion.

  10. Atmospheric discharges and particle fluxes

    NASA Astrophysics Data System (ADS)

    Chilingarian, A.; Chilingaryan, S.; Reymers, A.

    2015-07-01

    Fluxes of the electrons, gamma rays, and neutrons observed by particle detectors located on the Earth's surface during thunderstorms originate so-called Thunderstorm Ground Enhancements (TGEs). The relativistic runaway electron avalanches giving rise to TGEs originate in the thundercloud's lower dipole between the main negatively charged region in the middle of the thundercloud and transient lower positively charged region. Acceleration of electrons in the upper dipole between main negative and main positive charge regions leads to initiation of the terrestrial gamma flashes (TGFs) intensive researched during the last two decades by orbiting gamma ray observatories. TGFs are exceptionally intense, submillisecond bursts of electromagnetic radiation directed to the open space from the thunderstorm atmosphere. Unlike visible lightning, TGF beams do not create a hot plasma channel and optical flash; hence, in the literature they got name "dark lightning." We investigate the TGEs development in 1 min and 1 s time series of particle detector count rates. Synchronized time series of the near-surface electric field and lightning occurrences allows interconnecting two atmospheric phenomena. Registration of the Extensive Air Showers allows approaching problems of relation of the lightning occurrences and particle fluxes.

  11. Atmospheric Chemistry and Global Change

    NASA Astrophysics Data System (ADS)

    Wofsy, Steven C.

    Atmospheric Chemistry and Global Change is the result of the collective efforts of scientists at the National Center for Atmospheric Research (NCAR) to provide a comprehensive textbook for students at the graduate level and a reference book for teachers and scientists.There are 16 chapters, each authored by two or more NCAR scientists with contributions from many others, followed by a 2-page essay by a non- NCAR scientist reflecting on the subject matter.The book succeeds well beyond what one might expect from such a large group effort, with several chapters being true gems. For example, one is accustomed to reading chapters on dynamics and transport either written for dynamicists, thus incomprehensible to chemists, or simplified treatments or summaries written by chemists and lacking in real substance. Here the long chapter by Rolando Garcia et al. is outstanding in its clarity, completeness, and careful attention to both transport and the underlying principles and phenomena of geophysical fluid dynamics. It's not for the faint of heart (there are 162 equations and 32 figures), but the reader's effort is handsomely rewarded.

  12. Comprehending emergent systems phenomena through direct-manipulation animation

    NASA Astrophysics Data System (ADS)

    Aguirre, Priscilla Abel

    This study seeks to understand the type of interaction mode that best supports learning and comprehension of emergent systems phenomena. Given that the literature has established that students hold robust misconceptions of such phenomena, this study investigates the influence of using three types of interaction; speed-manipulation animation (SMN), post-manipulation animation (PMA) and direct-manipulation animation (DMA) for increasing comprehension and testing transfer of the phenomena, by looking at the effect of simultaneous interaction of haptic and visual channels on long term and working memories when seeking to comprehend emergent phenomena. The questions asked were: (1) Does the teaching of emergent phenomena, with the aid of a dynamic interactive modeling tool (i.e., SMA, PMA or DMA), improve students' mental model construction of systems, thus increasing comprehension of this scientific concept? And (2) does the teaching of emergent phenomena, with the aid of a dynamic interactive modeling tool, give the students the necessary complex cognitive skill which can then be applied to similar (near transfer) and/or novel, but different, (far transfer) scenarios? In an empirical study undergraduate and graduate students were asked to participate in one of three experimental conditions: SMA, PMA, or DMA. The results of the study found that it was the participants of the SMA treatment condition that had the most improvement in post-test scores. Students' understanding of the phenomena increased most when they used a dynamic model with few interactive elements (i.e., start, stop, and speed) that allowed for real time visualization of one's interaction on the phenomena. Furthermore, no indication was found that the learning of emergent phenomena, with the aid of a dynamic interactive modeling tool, gave the students the necessary complex cognitive skill which could then be applied to similar (near transfer) and/or novel, but different, (far transfer) scenarios. Finally, besides treatment condition, gender and age were also shown to be predictors of score differences; overall, males did better than females, and younger students did better than older students.

  13. PREFACE: Transport phenomena in proton conducting media Transport phenomena in proton conducting media

    NASA Astrophysics Data System (ADS)

    Eikerling, Michael

    2011-06-01

    Proton transport phenomena are of paramount importance for acid-base chemistry, energy transduction in biological organisms, corrosion processes, and energy conversion in electrochemical systems such as polymer electrolyte fuel cells. The relevance for such a plethora of materials and systems, and the ever-lasting fascination with the highly concerted nature of underlying processes drive research across disciplines in chemistry, biology, physics and chemical engineering. A proton never travels alone. Proton motion is strongly correlated with its environment, usually comprised of an electrolyte and a solid or soft host material. For the transport in nature's most benign proton solvent and shuttle, water that is, insights from ab initio simulations, matured over the last 15 years, have furnished molecular details of the structural diffusion mechanism of protons. Excess proton movement in water consists of sequences of Eigen-Zundel-Eigen transitions, triggered by hydrogen bond breaking and making in the surrounding water network. Nowadays, there is little debate about the validity of this mechanism in water, which bears a stunning resemblance to the basic mechanistic picture put forward by de Grotthuss in 1806. While strong coupling of an excess proton with degrees of freedom of solvent and host materials facilitates proton motion, this coupling also creates negative synergies. In general, proton mobility in biomaterials and electrochemical proton conducting media is highly sensitive to the abundance and structure of the proton solvent. In polymer electrolyte membranes, in which protons are bound to move in nano-sized water-channels, evaporation of water or local membrane dehydration due to electro-osmotic coupling are well-known phenomena that could dramatically diminish proton conductivity. Contributions in this special issue address various vital aspects of the concerted nature of proton motion and they elucidate important structural and dynamic effects of solvent, charge-bearing species at interfaces and porous host materials on proton transport properties. As a common thread, articles in this special issue contribute to understanding the functionality provided by complex materials, beyond hydrogen bond fluctuations in water. The first group of articles (Smirnov et al, Henry et al, Medvedev and Stuchebrukhov) elucidates various aspects of the impact of local structural fluctuations, hydrogen bonding and long-range electrostatic forces on proton transfer across and at the surface of mitochondrial membranes. The second group of articles (Ilhan and Spohr, Allahyarov et al and Idupulapati et al) employ molecular dynamics simulations to rationalize vital dependencies of proton transport mechanisms in aqueous-based polymer electrolyte membranes on the nanoporous, phase-separated ionomer morphology, and on the level of hydration. The articles by Gebel et al, Boillat et al, and Aleksandrova et al employ small angle neutron scattering, neutron radiography, and electrochemical atomic force microscopy, respectively, to obtain detailed insights into the kinetics of water sorption, water distribution, water transport properties, as well as spatial maps of proton conductivity in fuel cell membranes. The contribution of Paschos et al provides a comprehensive review of phosphate-based solid state protonic conductors for intermediate temperature fuel cells. The topic of proton conductive materials for high-temperature, water-free operation of fuel cells is continued in the article of Verbraeken et al which addresses synthesis and characterization of a proton conducting perovskite. The guest editor wishes to acknowledge and thank all contributing authors for their commitment to this special issue. Moreover, I would like to thank the staff at IOP Publishing for coordinating submission and refereeing processes. Finally, for the readers, I hope that this special issue will be a valuable and stimulating source of insights into the versatile and eminently important field of transport phenomena in proton conducting media. Complex dynamics of fluids in disordered and crowded environments contents Electrostatic models of electron-driven proton transfer across a lipid membrane Anatoly Yu Smirnov, Lev G Mourokh and Franco Nori Molecular basis of proton uptake in single and double mutants of cytochrome c oxidase Rowan M Henry, David Caplan, Elisa Fadda and Régis Pomès Proton diffusion along biological membranes E S Medvedev and A A Stuchebrukhov Ab initio molecular dynamics of proton networks in narrow polymer electrolyte pores Mehmet A Ilhan and Eckhard Spohr A simulation study of field-induced proton-conduction pathways in dry ionomers Elshad Allahyarov, Philip L Taylor and Hartmut Löwen Molecular structure and transport dynamics in perfluoro sulfonyl imide membranes Nagesh Idupulapati, Ram Devanathan and Michel Dupuis The kinetics of water sorption in Nafion membranes: a small-angle neutron scattering study Gérard Gebel, Sandrine Lyonnard, Hakima Mendil-Jakani and Arnaud Morin Using 2H labeling with neutron radiography for the study of solid polymer electrolyte water transport properties P Boillat, P Oberholzer, B C Seyfang, A Kästner, R Perego, G G Scherer, E H Lehmann and A Wokaun Spatial distribution and dynamics of proton conductivity in fuel cell membranes: potential and limitations of electrochemical atomic force microscopy measurements E Aleksandrova, S Hink, R Hiesgen and E Roduner A review on phosphate based, solid state, protonic conductors for intermediate temperature fuel cells O Paschos, J Kunze, U Stimming and F Maglia A structural study of the proton conducting B-site ordered perovskite Ba3Ca1.18Ta1.82O8.73 Maarten C Verbraeken, Hermenegildo A L Viana, Philip Wormald and John T S Irvine

  14. Atmospheric Pressure Indicator.

    ERIC Educational Resources Information Center

    Salzsieder, John C.

    1995-01-01

    Discusses observable phenomena related to air pressure. Describes a simple, unobtrusive, semiquantitative device to monitor the changes in air pressure that are associated with altitude, using a soft-drink bottle and a balloon. (JRH)

  15. Solid State Laser Technology Development for Atmospheric Sensing Applications

    NASA Technical Reports Server (NTRS)

    Barnes, James C.

    1998-01-01

    NASA atmospheric scientists are currently planning active remote sensing missions that will enable global monitoring of atmospheric ozone, water vapor, aerosols and clouds as well as global wind velocity. The measurements of these elements and parameters are important because of the effects they have on climate change, atmospheric chemistry and dynamics, atmospheric transport and, in general, the health of the planet. NASA will make use of Differential Absorption Lidar (DIAL) and backscatter lidar techniques for active remote sensing of molecular constituents and atmospheric phenomena from advanced high-altitude aircraft and space platforms. This paper provides an overview of NASA Langley Research Center's (LaRC's) development of advanced solid state lasers, harmonic generators, and wave mixing techniques aimed at providing the broad range of wavelengths necessary to meet measurement goals of NASA's Earth Science Enterprise.

  16. Present state of knowledge of the upper atmosphere: An assessment report

    NASA Technical Reports Server (NTRS)

    1984-01-01

    A program of research, technology, and monitoring of the phenomena of the upper atmosphere, to provide for an understanding of and to maintain the chemical and physical integrity of the Earth's upper atmosphere was developed. NASA implemented a long-range upper atmospheric science program aimed at developing an organized, solid body of knowledge of upper atmospheric processes while providing, in the near term, assessments of potential effects of human activities on the atmosphere. The effects of chlorofluorocarbon (CFC) releases on stratospheric ozone were reported. Issues relating the current understanding of ozone predictions and trends and highlights recent and future anticipated developments that will improve our understanding of the system are summarized.

  17. The Center for Natural Phenomena Engineering (CNPE), 1990--1991

    SciTech Connect

    1992-07-01

    The Center for Natural Phenomena Engineering (CNPE) was established to provide a natural phenomena (NP) engineering oversight role within Martin Marietta Energy Systems, Inc. (MMES). In this oversight role CNPE`s goals are to provide coordination and direction of activities related to earthquake and other natural phenomena engineering, including development of hazard definition, development of design criteria, conducting new facility design, development and conducting of testing, performance of analysis and vulnerability studies, development of analysis methodology, and provision of support for preparation of safety analysis reports for the five MMES sites. In conducting these activities it is CNPE`s goal to implement the elements of Total Quality Management (TQM) in a cost-effective manner, providing its customers with a quality product. This report describes 1990--1991 activities.

  18. Direct observation of thitherto unobservable quantum phenomena by using electrons

    PubMed Central

    Tonomura, Akira

    2005-01-01

    Fundamental aspects of quantum mechanics, which were discussed only theoretically as thought experiments in the 1920s and 1930s, have begun to frequently show up in nanoscopic regions owing to recent rapid progress in advanced technologies. Quantum phenomena were once regarded as the ultimate factors limiting further miniaturization trends of microstructured electronic devices, but now they have begun to be actively used as the principles for new devices such as quantum computers. To directly observe what had been unobservable quantum phenomena, we have tried to develop bright and monochromatic electron beams for the last 35 years. Every time the brightness of an electron beam improved, fundamental experiments in quantum mechanics became possible, and quantum phenomena became observable by using the wave nature of electrons. PMID:16150719

  19. Phenomena Identification and Ranking Technique (PIRT) Panel Meeting Summary Report

    SciTech Connect

    Mark Holbrook

    2007-07-01

    Phenomena Identification and Ranking Technique (PIRT) is a systematic way of gathering information from experts on a specific subject and ranking the importance of the information. NRC, in collaboration with DOE and the working group, conducted the PIRT exercises to identify safety-relevant phenomena for NGNP, and to assess and rank the importance and knowledge base for each phenomenon. The overall objective was to provide NRC with an expert assessment of the safety-relevant NGNP phenomena, and an overall assessment of R and D needs for NGNP licensing. The PIRT process was applied to five major topical areas relevant to NGNP safety and licensing: (1) thermofluids and accident analysis (including neutronics), (2) fission product transport, (3) high temperature materials, (4) graphite, and (5) process heat for hydrogen cogeneration.

  20. Modified Phenomena Identification and Ranking Table (PIRT) for Uncertainty Analysis

    SciTech Connect

    Gol-Mohamad, Mohammad P.; Modarres, Mohammad; Mosleh, Ali

    2006-07-01

    This paper describes a methodology of characterizing important phenomena, which is also part of a broader research by the authors called 'Modified PIRT'. The methodology provides robust process of phenomena identification and ranking process for more precise quantification of uncertainty. It is a two-step process of identifying and ranking methodology based on thermal-hydraulics (TH) importance as well as uncertainty importance. Analytical Hierarchical Process (AHP) has been used for as a formal approach for TH identification and ranking. Formal uncertainty importance technique is used to estimate the degree of credibility of the TH model(s) used to represent the important phenomena. This part uses subjective justification by evaluating available information and data from experiments, and code predictions. The proposed methodology was demonstrated by developing a PIRT for large break loss of coolant accident LBLOCA for the LOFT integral facility with highest core power (test LB-1). (authors)

  1. Modeling and simulation of transport phenomena in ionic gels

    NASA Astrophysics Data System (ADS)

    Leichsenring, Peter; Wallmersperger, Thomas

    2015-04-01

    Ionic hydrogels belong to the class of polyelectrolyte gels or ionic gels. Their ability to swell or shrink under different environmental conditions such as change of pH, ion concentration or temperature make them promising materials, e.g. for microsensoric or microactuatoric devices. The hydrogel swelling exhibits nonlinear effects due to the occurrence of different interacting transport phenomena. Numerical simulations are an essential part in the ongoing development of microsensors and microactuators. In order to determine transport effects due to diffusion, migration and convection a multiphase mesoscale model based on the Theory of Porous Media is applied. The governing field equations are solved in the transient regime by applying the Finite Element Method. By means of the derived numerical framework a detailed investigation of the different transport phenomena is carried out. Numerical experiments are performed to characterize the dominating transfer phenomena for ionic gels under chemical stimulation.

  2. An assessment of Gallistel's (2012) rationalistic account of extinction phenomena.

    PubMed

    Miller, Ralph R

    2012-05-01

    Gallistel (2012) asserts that animals use rationalistic reasoning (i.e., information theory and Bayesian inference) to make decisions that underlie select extinction phenomena. Rational processes are presumed to lead to evolutionarily optimal behavior. Thus, Gallistel's model is a type of optimality theory. But optimality theory is only a theory, a theory about an ideal organism, and its predictions frequently deviate appreciably from observed behavior of animals in the laboratory and the real world. That is, behavior of animals is often far from optimal, as is evident in many behavioral phenomena. Hence, appeals to optimality theory to explain, rather than illuminate, actual behavior are misguided. PMID:22421221

  3. Quantum Simulator for Transport Phenomena in Fluid Flows.

    PubMed

    Mezzacapo, A; Sanz, M; Lamata, L; Egusquiza, I L; Succi, S; Solano, E

    2015-01-01

    Transport phenomena still stand as one of the most challenging problems in computational physics. By exploiting the analogies between Dirac and lattice Boltzmann equations, we develop a quantum simulator based on pseudospin-boson quantum systems, which is suitable for encoding fluid dynamics transport phenomena within a lattice kinetic formalism. It is shown that both the streaming and collision processes of lattice Boltzmann dynamics can be implemented with controlled quantum operations, using a heralded quantum protocol to encode non-unitary scattering processes. The proposed simulator is amenable to realization in controlled quantum platforms, such as ion-trap quantum computers or circuit quantum electrodynamics processors. PMID:26278968

  4. Quantum Simulator for Transport Phenomena in Fluid Flows

    NASA Astrophysics Data System (ADS)

    Mezzacapo, A.; Sanz, M.; Lamata, L.; Egusquiza, I. L.; Succi, S.; Solano, E.

    2015-08-01

    Transport phenomena still stand as one of the most challenging problems in computational physics. By exploiting the analogies between Dirac and lattice Boltzmann equations, we develop a quantum simulator based on pseudospin-boson quantum systems, which is suitable for encoding fluid dynamics transport phenomena within a lattice kinetic formalism. It is shown that both the streaming and collision processes of lattice Boltzmann dynamics can be implemented with controlled quantum operations, using a heralded quantum protocol to encode non-unitary scattering processes. The proposed simulator is amenable to realization in controlled quantum platforms, such as ion-trap quantum computers or circuit quantum electrodynamics processors.

  5. Efficient Attosecond Phenomena in the Relativistic {lambda}3 Regime

    SciTech Connect

    Naumova, Natalia; Mourou, Gerard; Nees, John

    2006-04-07

    Particle-in-cell simulations of relativistically strong laser pulses interacting with overdense plasma targets predict that coherent motion of electrons leads to the efficient generation of strong attosecond electromagnetic pulses and dense attosecond electron bunches. The optimal conditions for these attosecond phenomena are achieved in the {lambda}3 regime, when few-cycle laser pulses are focused to a wavelength-limited spot, producing maximal intensity and maximal gradients with a given energy. The natural synchronism of these attosecond phenomena should enable a kind of relativistic attosecond optoelectronics.

  6. Fundamental investigation of duct/ESP phenomena. Final report

    SciTech Connect

    Brown, C.A.; Durham, M.D.; Sowa, W.A.; 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)

  7. Quantum Simulator for Transport Phenomena in Fluid Flows

    PubMed Central

    Mezzacapo, A.; Sanz, M.; Lamata, L.; Egusquiza, I. L.; Succi, S.; Solano, E.

    2015-01-01

    Transport phenomena still stand as one of the most challenging problems in computational physics. By exploiting the analogies between Dirac and lattice Boltzmann equations, we develop a quantum simulator based on pseudospin-boson quantum systems, which is suitable for encoding fluid dynamics transport phenomena within a lattice kinetic formalism. It is shown that both the streaming and collision processes of lattice Boltzmann dynamics can be implemented with controlled quantum operations, using a heralded quantum protocol to encode non-unitary scattering processes. The proposed simulator is amenable to realization in controlled quantum platforms, such as ion-trap quantum computers or circuit quantum electrodynamics processors. PMID:26278968

  8. SNFP detonation phenomena of hydrogen/oxygen in spent fuel containers

    SciTech Connect

    Cooper, T.D.

    1996-05-30

    Movement of spent nuclear fuels from the Hanford K Basins near the Columbia River to dry interim storage facility on the Hanford plateau will require repackaging the fuel in the basin into multi-canister overpacks (MCOs), drying of the fuel, transporting the contained fuel, hot conditioning, and finally interim storage. Each of these functions will be accomplished while the fuel is contained in the MCOs. Hydrogen and oxygen can be generated within the MCOs by several mechanisms. The principal source of hydrogen and oxygen within the MCOs is residual water from the vacuum drying and hot conditioning operations. This document assesses the detonation phenomena of hydrogen and oxygen in the spent fuel containers. Several process scenarios have been identified that could generate detonation pressures that exceed the nominal 10 atmosphere design limit of the MCOs. Only 42 grams of radiolized water are required to establish this condition.

  9. Spent nuclear fuel project detonation phenomena of hydrogen/oxygen in spent fuel containers

    SciTech Connect

    Cooper, T.D.

    1996-09-30

    Movement of Spent N Reactor fuels from the Hanford K Basins near the Columbia River to Dry interim storage facility on the Hanford plateau will require repackaging the fuel in the basins into multi-canister overpacks (MCOs), drying of the fuel, transporting the contained fuel, hot conditioning, and finally interim storage. Each of these functions will be accomplished while the fuel is contained in the MCOs by several mechanisms. The principal source of hydrogenand oxygen within the MCOs is residual water from the vacuum drying and hot conditioning operations. This document assesses the detonation phenomena of hydrogen and oxygen in the spent fuel containers. Several process scenarios have been identified that could generate detonation pressures that exceed the nominal 10 atmosphere design limit ofthe MCOS. Only 42 grams of radiolized water are required to establish this condition.

  10. Our shared atmosphere

    EPA Science Inventory

    Our atmosphere is a precious and fascinating resource, providing air to breath, shielding us from harmful ultraviolet radiation (UV), and maintaining a comfortable climate. Since the industrial revolution, people have significantly altered the composition of the atmosphere throu...

  11. The Atmosphere of Venus

    NASA Technical Reports Server (NTRS)

    Hansen, J. E. (Editor)

    1975-01-01

    Topics considered at the conference included the dynamics, structure, chemistry, and evolution of the Venus atmosphere, as well as cloud physics and motion. Infrared, ultraviolet, and radio occultation methods of analysis are discussed, and atmospheric models are described.

  12. Stellar atmospheric structural patterns

    NASA Technical Reports Server (NTRS)

    Thomas, R. N.

    1983-01-01

    The thermodynamics of stellar atmospheres is discussed. Particular attention is given to the relation between theoretical modeling and empirical evidence. The characteristics of distinctive atmospheric regions and their radical structures are discussed.

  13. The corrosion phenomena in the coin cell BR2325 of the ``superstoichiometric fluorocarbon-lithium'' system

    SciTech Connect

    Mitkin, V.N.; Galkin, P.S.; Denisova, T.N.

    1998-07-01

    It was noted at the earlier study and at the longer observations of the novel various types of superstoichiometric fluorocarbon materials CF{sub 1+x}, where x = 0.1--0.33 (FCM) and their behavior, that despite of their known hygroscopity during a storage of samples in laboratory and technological utensils nevertheless occurs an appreciable sorption of atmospheric moisture. The color of samples does not change but sometimes there appears a smell of hydrogen fluoride and even corrosion of glasswares at a long storage. On the basis of these facts was assumed that at a long storage the slow reactions of HF producing with a sorption moisture can proceed. This phenomena is necessary to take into account for successful manufacturing of long life lithium cells based on superstoichiometric fluorocarbon composite cathodes (FCC). The chemistry of such slow hydrolytic process and especially of processes which can proceed at manufacturing of FCC earlier was not investigated also of any data in the literature in this occasion is not present. Just for this reason the authors undertook a study of the corrosion phenomena which can proceed in industrial sources of a current at a long storage under influence of slow hydrolysis of C-F bonds by moisture. The goal of the study was to search long term damages in the slightly wet FCM and based on these materials cathodic composites for fluorocarbon-lithium cells. As a model for corrosion process investigation they have chosen a standard coin lithium battery of a type BR2325.

  14. Ground-based Optical Observations of Geophysical Phenomena: Aurora Borealis and Meteors

    NASA Astrophysics Data System (ADS)

    Samara, Marilia

    2010-10-01

    Advances in low-light level imaging technology have enabled significant improvements in the ground based study of geophysical phenomena. In this talk we focus on two such phenomena that occur in the Earth's ionosphere: aurorae and meteors. Imaging the aurora which is created by the interplay of the Earth's magnetosphere, ionosphere and atmosphere, provides a tool for remote sensing physical processes that are otherwise very difficult to study. By quantifying the intensities, scale sizes and lifetimes of auroral structures, we can gain significant insight into the physics behind the generation of the aurora and the interaction of the magnetosphere with the solar wind. Additionally, the combination of imaging with radars provides complimentary data and therefore more information than either method on its own. Meteor observations are a perfect example of this because the radar can accurately determine only the line-of-sight component of velocity, while imaging provides the direction of motion, the perpendicular velocity and brightness (a proxy for mass), therefore enabling a much more accurate determination of the full velocity vector and mass.

  15. Characterization of Microwave-Induced Electric Discharge Phenomena in Metal–Solvent Mixtures

    PubMed Central

    Chen, Wen; Gutmann, Bernhard; Kappe, C Oliver

    2012-01-01

    Electric discharge phenomena in metal–solvent mixtures are investigated utilizing a high field density, sealed-vessel, single-mode 2.45 GHz microwave reactor with a built-in camera. Particular emphasis is placed on studying the discharges exhibited by different metals (Mg, Zn, Cu, Fe, Ni) of varying particle sizes and morphologies in organic solvents (e.g., benzene) at different electric field strengths. Discharge phenomena for diamagnetic and paramagnetic metals (Mg, Zn, Cu) depend strongly on the size of the used particles. With small particles, short-lived corona discharges are observed that do not lead to a complete breakdown. Under high microwave power conditions or with large particles, however, bright sparks and arcs are experienced, often accompanied by solvent decomposition and formation of considerable amounts of graphitized material. Small ferromagnetic Fe and Ni powders (<40 μm) are heated very rapidly in benzene suspensions and start to glow in the microwave field, whereas larger particles exhibit extremely strong discharges. Electric discharges were also observed when Cu metal or other conductive materials such as silicon carbide were exposed to the microwave field in the absence of a solvent in an argon or nitrogen atmosphere. PMID:24551491

  16. In Situ Visualization of Impacting Phenomena of Plasma-Sprayed Zirconia: From Single Splat to Coating Formation

    NASA Astrophysics Data System (ADS)

    Shinoda, Kentaro; Murakami, Hideyuki; Kuroda, Seiji; Takehara, Kohsei; Oki, Sachio

    2008-12-01

    The authors have developed an in situ monitoring system for particle impacts under atmospheric dc plasma spraying conditions. This system utilized a high-speed video camera coupled with a long-distance microscope, and was capable of capturing the particle-impinging phenomena at one million frames per second. To understand the coating formation mechanism, two approaches were attempted, i.e., observation of the single splat formation and the subsequent coating formation. In the former case, the deformation and cooling processes of yttria-stabilized zirconia (YSZ) droplets impinging on substrates were successfully captured. In the latter case, multiple-droplet-impacting phenomena were observed as an ensemble treatment. Representing the coating process, the tower formation (0-dimensional) and bead formation (1-dimensional) were observed under typical plasma spray conditions for thermal barrier coatings using a triggering system coupled with the motion of a robot. The obtained images clearly showed the coating formation resulting from the integration of single splats.

  17. Atmospheric Nitrogen Fluorescence Yield

    NASA Technical Reports Server (NTRS)

    Adams, J. H., Jr.; Christl, M. J.; Fountain, W. F.; Gregory, J. C.; Martens, K. U.; Sokolsky, Pierre; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Several existing and planned experiments estimate the energies of ultra-high energy cosmic rays from air showers using the atmospheric nitrogen fluorescence. The nitrogen fluorescence yield from air shower electrons depends on the atmospheric composition. We will discuss the uncertainties in the fluorescence yield form electrons in the real atmosphere and describe a concept for a small balloon payload to measure the atmospheric fluorescence yield as a function of attitude.

  18. Physics of the Sun and its Atmosphere

    NASA Astrophysics Data System (ADS)

    Dwivedi, B. N.; Narain, U.

    ch. 1. Recent advances in solar physics / B. N. Dwivedi -- ch. 2. Overview of the Sun / S. S. Hasan -- ch. 3. Seismic view of the Sun / S. M. Chitre and B. N. Dwivedi -- ch. 4. Solar magnetism / P. Venkatakrishnan and S. Gosain -- ch. 5. Waves and oscillations in the solar atmosphere / R. Erdlyi -- ch. 6. VUV spectroscopy of solar plasma / A. Mohan -- ch. 7. Active region diagnostics / H. E. Mason and D. Tripathi -- ch. 8. Hall effect and ambipolar diffusion in the lower solar atmosphere / V. Krishan -- ch. 9. On solar coronal heating mechanisms / K. Pandey and U. Narain -- ch. 10. Coronal mass ejections (CMEs) and associated phenomena / N. Srivastava -- ch. 11. The radio Sun / P. K. Manoharan -- ch. 12. The solar wind / P. K. Manoharan -- ch. 13. The Sun-Earth system: our home in space / J. L. Lean.

  19. Sub-photosphere to Solar Atmosphere Connection

    NASA Astrophysics Data System (ADS)

    Komm, Rudolf; De Moortel, Ineke; Fan, Yuhong; Ilonidis, Stathis; Steiner, Oskar

    2015-12-01

    Magnetic fields extend from the solar interior through the atmosphere. The formation and evolution of active regions can be studied by measuring subsurface flows with local helioseismology. The emergence of magnetic flux from the solar convection zone is associated with acoustic perturbation signatures. In near-surface layers, the average dynamics can be determined for emerging regions. MHD simulations of the emergence of a twisted flux tube show how magnetic twist and free energy are transported from the interior into the corona and the dynamic signatures associated with such transport in the photospheric and sub-photospheric layers. The subsurface twisted flux tube does not emerge into the corona as a whole in emerging active regions. Shear flows at the polarity inversion line and coherent vortical motions in the subsurface flux tubes are the major means by which twist is transported into the corona, leading to the formation of sigmoid-shaped coronal magnetic fields capable of driving solar eruptions. The transport of twist can be followed from the interior by using the kinetic helicity of subsurface flows as a proxy of magnetic helicity; this quantity holds great promise for improving the understanding of eruptive phenomena. Waves are not only vital for studying the link between the solar interior and the surface but for linking the photosphere with the corona as well. Acoustic waves that propagate from the surface into the magnetically structured, dynamic atmosphere undergo mode conversion and refraction. These effects enable atmospheric seismology to determine the topography of magnetic canopies in the solar atmosphere. Inclined magnetic fields lower the cut-off frequency so that low frequency waves can leak into the outer atmosphere. Recent high resolution, high cadence observations of waves and oscillations in the solar atmosphere, have lead to a renewed interest in the potential role of waves as a heating mechanism. In light of their potential contribution to the heating of the solar atmosphere, some of the recent observations of waves and oscillations and ongoing modelling efforts are reviewed.

  20. Beyond a Dichotomic Approach, the Case of Colour Phenomena

    ERIC Educational Resources Information Center

    Viennot, L.; de Hosson, C.

    2012-01-01

    This research documents the aims and the impact of a teaching experiment concerning colour phenomena. This teaching experiment is designed in order to make students consider not only the spectral composition of light but also its intensity, and to consider the absorption of light by a pigment as relative, instead of as total or zero. Eight

  1. An Initial Investigation of the Psychedelic Drug Flashback Phenomena

    ERIC Educational Resources Information Center

    Matefy, Robert E.; Krall, Roger G.

    1974-01-01

    This study investigated some characteristics of persons experiencing "flashbacks," and provides systematic descriptions of the flashback phenomena. The drug user showed no significant differences in psychopathological characteristics as measured by the MMPI, nor significant differences in attentional processes as measured by the Embedded Figures

  2. A Detailed Analysis of a Child's Conception of Physical Phenomena.

    ERIC Educational Resources Information Center

    Golshan, Mahtash Esfandiari

    Reported is a method of investigating thought processes of an 11-year-old girl concerning physical phenomena such as those underlying the operations of scientific apparatus--platform balance, the spring balance, the magnet, and the pendulum. It was discovered during a period of interviews that the subject's thought processes developed in such a

  3. A Curriculum Framework Based on Archetypal Phenomena and Technologies.

    ERIC Educational Resources Information Center

    Zubrowski, Bernie

    2002-01-01

    Presents an alternative paradigm of curriculum development based on the theory of situated cognition. This approach starts with context rather than concept, gives greater weight to students' interpretative frameworks, and provides for a more holistic development. Presents a grade 1-8 framework that uses archetypal phenomena and technologies as the…

  4. Linguistic Studies on English Pronominalization: Syntactic, Discourse and Pragmatic Phenomena.

    ERIC Educational Resources Information Center

    Barnitz, John G.

    To integrate many of the theoretical linguistic studies examining pronoun reference, this paper focuses on tracing the shift from purely transformational syntactic studies of intrasentential phenomena to the wider orientations of discourse and pragmatic studies. The first section describes the classic studies of pronominalization within the…

  5. Beyond a Dichotomic Approach, the Case of Colour Phenomena

    ERIC Educational Resources Information Center

    Viennot, L.; de Hosson, C.

    2012-01-01

    This research documents the aims and the impact of a teaching experiment concerning colour phenomena. This teaching experiment is designed in order to make students consider not only the spectral composition of light but also its intensity, and to consider the absorption of light by a pigment as relative, instead of as total or zero. Eight…

  6. New Phenomena in NC Field Theory and Emergent Spacetime Geometry

    NASA Astrophysics Data System (ADS)

    Ydri, Badis

    2010-10-01

    We give a brief review of two nonperturbative phenomena typical of noncommutative field theory which are known to lead to the perturbative instability known as the UV-IR mixing. The first phenomena concerns the emergence/evaporation of spacetime geometry in matrix models which describe perturbative noncommutative gauge theory on fuzzy backgrounds. In particular we show that the transition from a geometrical background to a matrix phase makes the description of noncommutative gauge theory in terms of fields via the Weyl map only valid below a critical value g*. The second phenomena concerns the appearance of a nonuniform ordered phase in noncommutative scalar ?4 field theory and the spontaneous symmetry breaking of translational/rotational invariance which happens even in two dimensions. We argue that this phenomena also originates in the underlying matrix degrees of freedom of the noncommutative field theory. Furthermore it is conjectured that in addition to the usual WF fixed point at ? = 0 there must exist a novel fixed point at ? = ? corresponding to the quartic hermitian matrix model.

  7. Development of Understanding of Selected Science Phenomena in Young Children.

    ERIC Educational Resources Information Center

    Donaldson, Marcia Jackson

    The major purpose of this study was to investigate developmental patterns of understandings of four types of selected phenomena possessed by economically and racially different boys and girls. A total of 64 boys and girls, 32 blacks and 32 whites, were selected from Head Start, kindergarten, nursery, and primary schooling environments and then

  8. Binding Phenomena within a Reductionist Theory of Grammatical Dependencies

    ERIC Educational Resources Information Center

    Drummond, Alex

    2011-01-01

    This thesis investigates the implications of binding phenomena for the development of a reductionist theory of grammatical dependencies. The starting point is the analysis of binding and control in Hornstein (2001, 2009). A number of revisions are made to this framework in order to develop a simpler and empirically more successful account of

  9. Undergraduate Laboratory Experiment Modules for Probing Gold Nanoparticle Interfacial Phenomena

    ERIC Educational Resources Information Center

    Karunanayake, Akila G.; Gunatilake, Sameera R.; Ameer, Fathima S.; Gadogbe, Manuel; Smith, Laura; Mlsna, Deb; Zhang, Dongmao

    2015-01-01

    Three gold-nanoparticle (AuNP) undergraduate experiment modules that are focused on nanoparticles interfacial phenomena have been developed. Modules 1 and 2 explore the synthesis and characterization of AuNPs of different sizes but with the same total gold mass. These experiments enable students to determine how particle size affects the AuNP…

  10. Many-body phenomena in QED-cavity arrays [Invited

    SciTech Connect

    Tomadin, A.; Fazio, Rosario

    2010-06-15

    Coupled quantum electrodynamics (QED) cavities have been recently proposed as new systems to simulate a variety of equilibrium and nonequilibrium many-body phenomena. We present a brief review of their main properties together with a survey of the latest developments of the field and some perspectives concerning their experimental realizations and possible new theoretical directions.

  11. The Effects of Globalization Phenomena on Educational Concepts

    ERIC Educational Resources Information Center

    Schrottner, Barbara Theresia

    2010-01-01

    It is becoming more and more apparent that globalization processes represent, theoretically as well as practically, a challenge for educational sciences and therefore, it must be addressed within the sphere of education. Accordingly, educational conceptions have to adapt to globalization phenomena and focus more on alternative and innovative

  12. Developing Critical Thinking through the Study of Paranormal Phenomena.

    ERIC Educational Resources Information Center

    Wesp, Richard; Montgomery, Kathleen

    1998-01-01

    Argues that accounts of paranormal phenomena can serve as an ideal medium in which to encourage students to develop critical-thinking skills. Describes a cooperative-learning approach used to teach critical thinking in a course on paranormal events. Reports that critical-thinking skills increased and that the course received favorable student…

  13. Unipolar arcing phenomena observed in laboratory and nature

    SciTech Connect

    Sanduloviciu, M.

    1995-12-31

    Unipolar arcing phenomena observed as coherent {open_quotes}plasma{close_quotes} balls operating on a surface of constant potential are explained in the frame of a new already proposed self-organisation mechanism considered at the origin of the formation and stability of extended coherent structures observed in plasma devices.

  14. The Discovery of Transient Phenomena by NASA's K2 Mission

    NASA Astrophysics Data System (ADS)

    Colón, Knicole D.

    2016-01-01

    The NASA K2 space mission is photometrically monitoring fields along the ecliptic to achieve a variety of science goals. These goals involve time variable observations of Solar System objects, extrasolar planets, star clusters, supernovae, and more. Because K2 observes each of its fields for just ~80 days, it has a finite baseline over which to acquire observations of photometrically varying astrophysical objects. Thanks to their extended baseline of observations, wide-field ground-based photometric and spectroscopic surveys that have been monitoring the sky for years can provide robust constraints on transiting planets, supernova events, or other transient phenomena that have been newly identified in K2 data. I will discuss the opportunities for synergistic activities between the K2 space mission and such long-running ground-based surveys as HATNet, KELT, SuperWASP, and APOGEE that will maximize the scientific output from these surveys. In particular, I will present results from a search for transient phenomena in K2 data and will use ground-based survey data to aid the characterization of these phenomena. Examples of these phenomena include single planetary transit events and stars with long-duration dimmings caused by an eclipse of a protoplanetary disk. I will also discuss the benefits that upcoming surveys like the NASA Transiting Exoplanet Survey Satellite (TESS) mission and the Large Synoptic Survey Telescope (LSST) will gain from long-term ground-based surveys.

  15. Undergraduate Laboratory Experiment Modules for Probing Gold Nanoparticle Interfacial Phenomena

    ERIC Educational Resources Information Center

    Karunanayake, Akila G.; Gunatilake, Sameera R.; Ameer, Fathima S.; Gadogbe, Manuel; Smith, Laura; Mlsna, Deb; Zhang, Dongmao

    2015-01-01

    Three gold-nanoparticle (AuNP) undergraduate experiment modules that are focused on nanoparticles interfacial phenomena have been developed. Modules 1 and 2 explore the synthesis and characterization of AuNPs of different sizes but with the same total gold mass. These experiments enable students to determine how particle size affects the AuNP

  16. Developing Critical Thinking through the Study of Paranormal Phenomena.

    ERIC Educational Resources Information Center

    Wesp, Richard; Montgomery, Kathleen

    1998-01-01

    Argues that accounts of paranormal phenomena can serve as an ideal medium in which to encourage students to develop critical-thinking skills. Describes a cooperative-learning approach used to teach critical thinking in a course on paranormal events. Reports that critical-thinking skills increased and that the course received favorable student

  17. Coastal Sand Dune Plant Ecology: Field Phenomena and Interpretation

    ERIC Educational Resources Information Center

    McDonald, K.

    1973-01-01

    Discusses the advantages and disadvantages of selecting coastal sand dunes as the location for field ecology studies. Presents a descriptive zonal model for seaboard sand dune plant communities, suggestions concerning possible observations and activities relevant to interpreting phenomena associated with these forms of vegetation, and additional

  18. The Simulation Of Residual Tidal Phenomena In The White Sea

    NASA Astrophysics Data System (ADS)

    May, R. I.

    2004-12-01

    Residual tidal phenomena (residual tidal circulation and residual tidal level) in the White Sea play a significant role in energy contribution to the formation of the hydrological regime. Non-linear residual tidal currents and sea level due to energy exchanges from the basic harmonics to the high frequency part of the spectrum have been poorly investigated in the White Sea until now. But residual tidal phenomena play an important role in the general circulation, which affects the temperature distribution and the drift of ice, plankton, pollution and other conservative tracers. We carried out numerical experiments with a non-linear hydrodynamic model to estimate the contributions of (shallow, friction and convective) nonlinearities to the residual tidal phenomena of White Sea's, using a `consecutive realisation' technique. The model grid's spatio-temporal resolution is more detailed than before: the Earth's geoid is approximated by the Krasovskiy rotation ellipsoid. A residual tidal level is observed in the low frequency part of spectrum of model results. In the linear approximation, the spectral density has a dominant peak at the frequencies of the basic harmonics in all parts of the sea, and the residual level was absent; overtones were not expressed. The experiments revealed that the residual circulation was defined by the convective non-linearity. The Earth's rotation does not change the current structure: only the circulation intensity decreases. These results will enhance the knowledge of tidal phenomena in the White Sea, and can be used for navigation, ecology and fisheries research.

  19. Nuclear phenomena in low-energy nuclear reaction research

    NASA Astrophysics Data System (ADS)

    Krivit, Steven B.

    2013-09-01

    This is a comment on Storms (Naturwissenschaften 97:861-881, 2010) Status of Cold Fusion, Naturwissenschaften, 97:861-881. This comment provides the following corrections: other nuclear phenomena observed in low-energy nuclear reactions aside from helium-4 make significant contributions to the overall energy balance; and normal hydrogen, not just heavy hydrogen, produces excess heat.

  20. Nuclear phenomena in low-energy nuclear reaction research.

    PubMed

    Krivit, Steven B

    2013-09-01

    This is a comment on Storms E (2010) Status of Cold Fusion, Naturwissenschaften 97:861-881. This comment provides the following remarks to other nuclear phenomena observed in low-energy nuclear reactions aside from helium-4 make significant contributions to the overall energy balance; and normal hydrogen, not just heavy hydrogen, produces excess heat. PMID:23949247

  1. New Phenomena in NC Field Theory and Emergent Spacetime Geometry

    SciTech Connect

    Ydri, Badis

    2010-10-31

    We give a brief review of two nonperturbative phenomena typical of noncommutative field theory which are known to lead to the perturbative instability known as the UV-IR mixing. The first phenomena concerns the emergence/evaporation of spacetime geometry in matrix models which describe perturbative noncommutative gauge theory on fuzzy backgrounds. In particular we show that the transition from a geometrical background to a matrix phase makes the description of noncommutative gauge theory in terms of fields via the Weyl map only valid below a critical value g*. The second phenomena concerns the appearance of a nonuniform ordered phase in noncommutative scalar {phi}{sup 4} field theory and the spontaneous symmetry breaking of translational/rotational invariance which happens even in two dimensions. We argue that this phenomena also originates in the underlying matrix degrees of freedom of the noncommutative field theory. Furthermore it is conjectured that in addition to the usual WF fixed point at {theta} = 0 there must exist a novel fixed point at {theta} = {infinity} corresponding to the quartic hermitian matrix model.

  2. Eighty phenomena about the self: representation, evaluation, regulation, and change

    PubMed Central

    Thagard, Paul; Wood, Joanne V.

    2015-01-01

    We propose a new approach for examining self-related aspects and phenomena. The approach includes (1) a taxonomy and (2) an emphasis on multiple levels of mechanisms. The taxonomy categorizes approximately eighty self-related phenomena according to three primary functions involving the self: representing, effecting, and changing. The representing self encompasses the ways in which people depict themselves, either to themselves or to others (e.g., self-concepts, self-presentation). The effecting self concerns ways in which people facilitate or limit their own traits and behaviors (e.g., self-enhancement, self-regulation). The changing self is less time-limited than the effecting self; it concerns phenomena that involve lasting alterations in how people represent and control themselves (e.g., self-expansion, self-development). Each self-related phenomenon within these three categories may be examined at four levels of interacting mechanisms (social, individual, neural, and molecular). We illustrate our approach by focusing on seven self-related phenomena. PMID:25870574

  3. Nonisothermal Pluto atmosphere models

    SciTech Connect

    Hubbard, W.B.; Yelle, R.V.; Lunine, J.I. )

    1990-03-01

    The present thermal profile calculation for a Pluto atmosphere model characterized by a high number fraction of CH4 molecules encompasses atmospheric heating by solar UV flux absorption and conductive transport cooling to the surface of Pluto. The stellar occultation curve predicted for an atmosphere of several-microbar surface pressures (which entail the existence of a substantial temperature gradient close to the surface) agrees with observations and implies that the normal and tangential optical depth of the atmosphere is almost negligible. The minimum period for atmospheric methane depletion is calculated to be 30 years. 29 refs.

  4. Planetary Atmospheres, Basic Thermodynamics and Regimes

    NASA Astrophysics Data System (ADS)

    Smith, Arthur

    1997-05-01

    In Sessions 2 to 4 we shall revue some of the basic phenomena relevant to capsule aerothermodynamics prior to the more detailed Sessions later in the course. Much of the material in these first Sessions is undergraduate material and refers to simple methods in order to introduce the student to the subject with the emphasis on understanding the phenomena rather than a briefing on state of the art techniques. However understanding aerothermodynamics requires understanding of basic mathematics, physics and chemistry which is assumed for this course. A short list of references is given to each section which has deliberately been kept small such that the student should aim to read all of these in detail. Some of the classic works have been included which although early give good detailed explanations of the subject phenomena. Session 2 Begins with the atmosphere structure followed by some basic thermodynamics used in aerothermodynamics, and ends with a revue of the classical aerodynamic and aerothermal regimes encountered by a capsule during entry.

  5. Therapeutic potential of atmospheric neutrons

    PubMed Central

    Voyant, Cyril; Roustit, Rudy; Tatje, Jennifer; Biffi, Katia; Leschi, Delphine; Briançon, Jérome; Marcovici, Céline Lantieri

    2010-01-01

    Background Glioblastoma multiform (GBM) is the most common and most aggressive type of primary brain tumour in humans. It has a very poor prognosis despite multi-modality treatments consisting of open craniotomy with surgical resection, followed by chemotherapy and/or radiotherapy. Recently, a new treatment has been proposed – Boron Neutron Capture Therapy (BNCT) – which exploits the interaction between Boron-10 atoms (introduced by vector molecules) and low energy neutrons produced by giant accelerators or nuclear reactors. Methods The objective of the present study is to compute the deposited dose using a natural source of neutrons (atmospheric neutrons). For this purpose, Monte Carlo computer simulations were carried out to estimate the dosimetric effects of a natural source of neutrons in the matter, to establish if atmospheric neutrons interact with vector molecules containing Boron-10. Results The doses produced (an average of 1 μGy in a 1 g tumour) are not sufficient for therapeutic treatment of in situ tumours. However, the non-localised yet specific dosimetric properties of 10B vector molecules could prove interesting for the treatment of micro-metastases or as (neo)adjuvant treatment. On a cellular scale, the deposited dose is approximately 0.5 Gy/neutron impact. Conclusion It has been shown that BNCT may be used with a natural source of neutrons, and may potentially be useful for the treatment of micro-metastases. The atmospheric neutron flux is much lower than that utilized during standard NBCT. However the purpose of the proposed study is not to replace the ordinary NBCT but to test if naturally occurring atmospheric neutrons, considered to be an ionizing pollution at the Earth's surface, can be used in the treatment of a disease such as cancer. To finalize this study, it is necessary to quantify the biological effects of the physically deposited dose, taking into account the characteristics of the incident particles (alpha particle and Lithium atom) and radio-induced effects (by-stander and low dose effect). One of the aims of the presented paper is to propose to experimental teams (which would be interested in studying the phenomena) a simple way to calculate the dose deposition (allometric fit of free path, transmission factor of brain). PMID:24669300

  6. Seasonality of alcohol-related phenomena in Estonia

    NASA Astrophysics Data System (ADS)

    Silm, Siiri; Ahas, Rein

    2005-03-01

    We studied alcohol consumption and its consequences as a seasonal phenomenon in Estonia and analysed the social and environmental factors that may cause its seasonal rhythm. There are two important questions when researching the seasonality of human activities: (1) whether it is caused by natural or social factors, and (2) whether the impact of the factors is direct or indirect. Often the seasonality of social phenomena is caused by social factors, but the triggering mechanisms are related to environmental factors like temperature, precipitation, and radiation via the circannual calendar. The indicators of alcohol consumption in the current paper are grouped as: (1) pre-consumption phenomena, i.e. production, tax and excise, sales (beer, wine and vodka are analysed separately), and (2) post-consumption phenomena, i.e. alcohol-related crime and traffic accidents and the number of people detained in lockups and admitted to alcohol treatment clinics. In addition, seasonal variability in the amount of alcohol advertising has been studied, and a survey has been carried out among 87 students of Tartu University. The analysis shows that different phenomena related to alcohol have a clear seasonal rhythm in Estonia. The peak period of phenomena related to beer is in the summer, from June to August and the low point is during the first months of the year. Beer consumption correlates well with air temperature. The consumption of vodka increases sharply at the end of the year and in June; the production of vodka does not have a significant correlation with negative temperatures. The consumption of wine increases during summer and in December. The consequences of alcohol consumption, expressed as the rate of traffic accidents or the frequency of medical treatment, also show seasonal variability. Seasonal variability of alcohol consumption in Estonia is influenced by natural factors (temperature, humidity, etc.) and by social factors (celebrations, vacations, etc.). However, distinguishing between impacts of direct and indirect relationships is complicated, as they are interlinked.

  7. Resistive switching phenomena: A review of statistical physics approaches

    NASA Astrophysics Data System (ADS)

    Lee, Jae Sung; Lee, Shinbuhm; Noh, Tae Won

    2015-09-01

    Resistive switching (RS) phenomena are reversible changes in the metastable resistance state induced by external electric fields. After discovery 50 years ago, RS phenomena have attracted great attention due to their potential application in next-generation electrical devices. Considerable research has been performed to understand the physical mechanisms of RS and explore the feasibility and limits of such devices. There have also been several reviews on RS that attempt to explain the microscopic origins of how regions that were originally insulators can change into conductors. However, little attention has been paid to the most important factor in determining resistance: how conducting local regions are interconnected. Here, we provide an overview of the underlying physics behind connectivity changes in highly conductive regions under an electric field. We first classify RS phenomena according to their characteristic current-voltage curves: unipolar, bipolar, and threshold switchings. Second, we outline the microscopic origins of RS in oxides, focusing on the roles of oxygen vacancies: the effect of concentration, the mechanisms of channel formation and rupture, and the driving forces of oxygen vacancies. Third, we review RS studies from the perspective of statistical physics to understand connectivity change in RS phenomena. We discuss percolation model approaches and the theory for the scaling behaviors of numerous transport properties observed in RS. Fourth, we review various switching-type conversion phenomena in RS: bipolar-unipolar, memory-threshold, figure-of-eight, and counter-figure-of-eight conversions. Finally, we review several related technological issues, such as improvement in high resistance fluctuations, sneak-path problems, and multilevel switching problems.

  8. Multipoint observations of plasma phenomena made in space by Cluster

    NASA Astrophysics Data System (ADS)

    Goldstein, M. L.; Escoubet, P.; Hwang, K.-Joo; Wendel, D. E.; Viñas, A.-F.; Fung, S. F.; Perri, S.; Servidio, S.; Pickett, J. S.; Parks, G. K.; Sahraoui, F.; Gurgiolo, C.; Matthaeus, W.; Weygand, J. M.

    2015-06-01

    Plasmas are ubiquitous in nature, surround our local geospace environment, and permeate the universe. Plasma phenomena in space give rise to energetic particles, the aurora, solar flares and coronal mass ejections, as well as many energetic phenomena in interstellar space. Although plasmas can be studied in laboratory settings, it is often difficult, if not impossible, to replicate the conditions (density, temperature, magnetic and electric fields, etc.) of space. Single-point space missions too numerous to list have described many properties of near-Earth and heliospheric plasmas as measured both in situ and remotely (see http://www.nasa.gov/missions/#.U1mcVmeweRY for a list of NASA-related missions). However, a full description of our plasma environment requires three-dimensional spatial measurements. Cluster is the first, and until data begin flowing from the Magnetospheric Multiscale Mission (MMS), the only mission designed to describe the three-dimensional spatial structure of plasma phenomena in geospace. In this paper, we concentrate on some of the many plasma phenomena that have been studied using data from Cluster. To date, there have been more than 2000 refereed papers published using Cluster data but in this paper we will, of necessity, refer to only a small fraction of the published work. We have focused on a few basic plasma phenomena, but, for example, have not dealt with most of the vast body of work describing dynamical phenomena in Earth's magnetosphere, including the dynamics of current sheets in Earth's magnetotail and the morphology of the dayside high latitude cusp. Several review articles and special publications are available that describe aspects of that research in detail and interested readers are referred to them (see for example, Escoubet et al. 2005 Multiscale Coupling of Sun-Earth Processes, p. 459, Keith et al. 2005 Sur. Geophys. 26, 307-339, Paschmann et al. 2005 Outer Magnetospheric Boundaries: Cluster Results, Space Sciences Series of ISSI. Berlin: Springer, Goldstein et al. 2006 Adv. Space Res. 38, 21-36, Taylor et al. 2010 The Cluster Mission: Space Plasma in Three Dimensions, Springer, pp. 309-330 and Escoubet et al. 2013 Ann. Geophys. 31, 1045-1059).

  9. Delusions, illusions and hallucinations in epilepsy: 1. Elementary phenomena.

    PubMed

    Elliott, Brent; Joyce, Eileen; Shorvon, Simon

    2009-08-01

    The purpose of this paper and its pair is to provide a comprehensive review, from the different perspectives of neurology and neuropsychiatry, of the phenomenology and mechanisms of hallucinatory experience in epilepsy. We emphasise the clinical and electrophysiological features, and make comparisons with the primary psychoses. In this paper, we consider definitions and elementary hallucinatory phenomena. Regarding definition, there is a clearly divergent evolution in meaning of the terms delusion, illusion and hallucination in the separate traditions of neurology and psychiatry. Psychiatry makes clear distinctions between the terms and has focussed on the empirical use of descriptive psychopathology in order to delineate the various psychiatric syndromes, including those in epilepsy. These distinctions in psychiatry have stood the test of time and are useful in clinical descriptive terms, but do not help to understand the basic mechanisms. The focus of neurology has been to regard delusions, illusions and hallucinations in epilepsy as a result of localised or network based neuronal epileptic activity that can be investigated especially using intracranial stereoelectroencephalography (SEEG). The neurological approach leads to a more synoptical definition of 'hallucination' than in psychiatry and to the conclusion that there is little point in differentiating hallucination from illusion or delusion in view of the overlap in the physiological bases of the phenomena. The semiologically derived differentiation of these terms in psychiatry is not supported by similarly discrete electrophysiological signatures. However, as discussed in the second paper, some psychotic states are associated with similar electrophysiological changes. The wide range of hallucinatory symptoms occurring during epileptic seizures recorded during intracranial SEEG and brain stimulation are reviewed here, including: experiential and interpretive phenomena, affective symptoms, as well as auditory, olfactory, gustatory, somatic and visual hallucinatory phenomena. Several conclusions can be drawn. First, it is clear that there is only limited anatomical specificity of many hallucinatory states. Repeated seizures or stimulation of a single area, even within the same patient can produce different psychic responses, whilst stimulation of widely distinct areas (especially in the limbic system) within the same individual can produce remarkably similar phenomena. This lack of specificity applies particularly to psychic symptoms, including experiential phenomena, and complex hallucinatory states. The most anatomically specific areas from this point of view are the elementary hallucinations arising from primary visual and auditory cortices. Involvement of the limbic cortex is a pre-requisite for the occurrence of complex hallucinatory states. It is clear that on the basis of these findings, as has been recognised at least since the 1960s, that even apparently focal epileptic seizures, (especially in the mesial temporal lobe, insula and limbic cortices), must involve widely distributed neuronal networks. PMID:19423297

  10. Cosmic dust in the earth's atmosphere.

    PubMed

    Plane, John M C

    2012-10-01

    This review discusses the magnitude of the cosmic dust input into the earth's atmosphere, and the resulting impacts from around 100 km to the earth's surface. Zodiacal cloud observations and measurements made with a spaceborne dust detector indicate a daily mass input of interplanetary dust particles ranging from 100 to 300 tonnes, which is in agreement with the accumulation rates of cosmic-enriched elements (Ir, Pt, Os and super-paramagnetic Fe) in polar ice cores and deep-sea sediments. In contrast, measurements in the middle atmosphere - by radar, lidar, high-flying aircraft and satellite remote sensing - indicate that the input is between 5 and 50 tonnes per day. There are two reasons why this huge discrepancy matters. First, if the upper range of estimates is correct, then vertical transport in the middle atmosphere must be considerably faster than generally believed; whereas if the lower range is correct, then our understanding of dust evolution in the solar system, and transport from the middle atmosphere to the surface, will need substantial revision. Second, cosmic dust particles enter the atmosphere at high speeds and undergo significant ablation. The resulting metals injected into the atmosphere are involved in a diverse range of phenomena, including: the formation of layers of metal atoms and ions; the nucleation of noctilucent clouds, which are a sensitive marker of climate change; impacts on stratospheric aerosols and O(3) chemistry, which need to be considered against the background of a cooling stratosphere and geo-engineering plans to increase sulphate aerosol; and fertilization of the ocean with bio-available Fe, which has potential climate feedbacks. PMID:22678029

  11. Cosmic dust in the earth's atmosphere

    NASA Astrophysics Data System (ADS)

    Plane, John M. C.

    2012-04-01

    This review discusses the magnitude of the cosmic dust input into the earth's atmosphere, and the resulting impacts from around 100 km to the earth's surface. Zodiacal cloud observations and measurements made with a spaceborne dust detector indicate a daily mass input of interplanetary dust particles ranging from 100 to 300 tonnes, which is in agreement with the accumulation rates of cosmic-enriched elements (Ir, Pt, Os and super-paramagnetic Fe) in polar ice cores and deep-sea sediments. In contrast, measurements in the middle atmosphere - by radar, lidar, high-flying aircraft and satellite remote sensing - indicate that the input is between 5 and 50 tonnes per day. There are two reasons why this huge discrepancy matters. First, if the upper range of estimates is correct, then vertical transport in the middle atmosphere must be considerably faster than generally believed; whereas if the lower range is correct, then our understanding of dust evolution in the solar system, and transport from the middle atmosphere to the surface, will need substantial revision. Second, cosmic dust particles enter the atmosphere at high speeds and undergo significant ablation. The resulting metals injected into the atmosphere are involved in a diverse range of phenomena, including: the formation of layers of metal atoms and ions; the nucleation of noctilucent clouds, which are a sensitive marker of climate change; impacts on stratospheric aerosols and O3 chemistry, which need to be considered against the background of a cooling stratosphere and geo-engineering plans to increase sulphate aerosol; and fertilization of the ocean with bio-available Fe, which has potential climate feedbacks.

  12. An Atmospheric Science Observing System Simulation Experiment (OSSE) Environment

    NASA Technical Reports Server (NTRS)

    Lee, Meemong; Weidner, Richard; Qu, Zheng; Bowman, Kevin; Eldering, Annmarie

    2010-01-01

    An atmospheric sounding mission starts with a wide range of concept designs involving measurement technologies, observing platforms, and observation scenarios. Observing system simulation experiment (OSSE) is a technical approach to evaluate the relative merits of mission and instrument concepts. At Jet Propulsion Laboratory (JPL), the OSSE team has developed an OSSE environment that allows atmospheric scientists to systematically explore a wide range of mission and instrument concepts and formulate a science traceability matrix with a quantitative science impact analysis. The OSSE environment virtually creates a multi-platform atmospheric sounding testbed (MAST) by integrating atmospheric phenomena models, forward modeling methods, and inverse modeling methods. The MAST performs OSSEs in four loosely coupled processes, observation scenario exploration, measurement quality exploration, measurement quality evaluation, and science impact analysis.

  13. Relativistic breakdown in planetary atmospheres

    NASA Astrophysics Data System (ADS)

    Dwyer, J. R.

    2007-04-01

    In 2003, a new electrical breakdown mechanism involving the production of runaway avalanches by positive feedback from runaway positrons and energetic photons was introduced. This mechanism, which shall be referred to as ``relativistic feedback,'' allows runaway discharges in gases to become self-sustaining, dramatically increasing the flux of runaway electrons, the accompanying high-energy radiation, and resulting ionization. Using detailed Monte Carlo calculations, properties of relativistic feedback are investigated. It is found that once relativistic feedback fully commences, electrical breakdown will occur and the ambient electric field, extending over cubic kilometers, will be discharged in as little as 2×10-5 s. Furthermore, it is found that the flux of energetic electrons and x rays generated by this mechanism can exceed the flux generated by the standard relativistic runaway electron model by a factor of 1013, making relativistic feedback a good candidate for explaining terrestrial gamma-ray flashes and other high-energy phenomena observed in the Earth's atmosphere.

  14. Relativistic breakdown in planetary atmospheres

    SciTech Connect

    Dwyer, J. R.

    2007-04-15

    In 2003, a new electrical breakdown mechanism involving the production of runaway avalanches by positive feedback from runaway positrons and energetic photons was introduced. This mechanism, which shall be referred to as 'relativistic feedback', allows runaway discharges in gases to become self-sustaining, dramatically increasing the flux of runaway electrons, the accompanying high-energy radiation, and resulting ionization. Using detailed Monte Carlo calculations, properties of relativistic feedback are investigated. It is found that once relativistic feedback fully commences, electrical breakdown will occur and the ambient electric field, extending over cubic kilometers, will be discharged in as little as 2x10{sup -5} s. Furthermore, it is found that the flux of energetic electrons and x rays generated by this mechanism can exceed the flux generated by the standard relativistic runaway electron model by a factor of 10{sup 13}, making relativistic feedback a good candidate for explaining terrestrial gamma-ray flashes and other high-energy phenomena observed in the Earth's atmosphere.

  15. Community Atmosphere Model

    Energy Science and Technology Software Center (ESTSC)

    2004-10-18

    The Community Atmosphere Model (CAM) is an atmospheric general circulation model that solves equations for atmospheric dynamics and physics. CAM is an outgrowth of the Community Climate Model at the National Center for Atmospheric Research (NCAR) and was developed as a joint collaborative effort between NCAR and several DOE laboratories, including LLNL. CAM contains several alternative approaches for advancing the atmospheric dynamics. One of these approaches uses a finite-volume method originally developed by personnel atmore » NASNGSFC, We have developed a scalable version of the finite-volume solver for massively parallel computing systems. FV-CAM is meant to be used in conjunction with the Community Atmosphere Model. It is not stand-alone.« less

  16. Pluto's atmosphere near perihelion

    SciTech Connect

    Trafton, L.M. )

    1989-11-01

    A recent stellar occultation has confirmed predictions that Pluto has an atmosphere which is sufficiently thick to uniformly envelope the planet and to extend far above the surface. Pluto's atmosphere consists of methane and perhaps other volatile gases at temperatures below their freezing points; it should regulate the surface temperature of its volatile ices to a globally uniform value. As Pluto approaches and passes through perihelion, a seasonal maximum in the atmospheric bulk and a corresponding minimum in the exposed volatile ice abundance is expected to occur. The lag in maximum atmospheric bulk relative to perihelion will be diagnostic of the surface thermal properties. An estimate of Pluto's atmospheric bulk may result if a global darkening (resulting from the disappearance of the seasonally deposited frosts) occurs before the time of maximum atmospheric bulk. The ice deposited shortly after perihelion may be diagnostic of the composition of Pluto's volatile reservoir.

  17. Waveguide beam splitters and recombiners based on multimode propagation phenomena

    NASA Astrophysics Data System (ADS)

    Jenkins, R. M.; Devereux, R. W. J.; Heaton, J. M.

    1992-07-01

    Novel waveguide beam splitters and recombiners based on multimode propagation phenomena in hollow step-index waveguides are predicted and demonstrated. The splitter designs are based on symmetrically feeding the fundamental-mode field from a square cross-section waveguide, 2a x 2a, into a multimode rectangular guide, 2a x 2b (b greater than a). As a result of multimode superposition phenomena, unique transverse-field patterns representing different-order multiway splitting of the input field occur at predictable positions along the rectangular-guide axis. The predictions are verified experimentally at 10.6 microns with hollow dielectric waveguides but are considered to be more widely applicable.

  18. Observation of microwave superfluid phenomena of multiple phase magnetic fluid

    NASA Astrophysics Data System (ADS)

    Kono, Kazuhito; Kono, Buhei

    2015-05-01

    We observe superfluid phenomena by microwaves irradiation to multiple phase magnetic fluid in room temperature or room pressure. Ferromagnetism transformation of diamagnetic or paramagnetic particles in multiple phase magnetic fluid containing constant rate of ferromagnetic particles, diamagnetic or paramagnetic particles mixing organic polyphenol and irradiation of microwaves is, observed by superexchange interaction. Superfluid phenomena are observed by irradiation of microwaves to aforementioned multiple phase of magnetic fluid containing ferromagnetism transformed diamagnetic or paramagnetic particles with ferromagnetic particles. Mixing semiconductor pigments amplifying superfluid energy by photosensitivity is observed. Visible light LED selecting wavelength is irradiated to superfluid condition of aforementioned multiple phase magnetic fluid thus magnetic field and energy of superfluid is enhanced by light quantum amplification effect.

  19. A universal mechanism of extreme events and critical phenomena

    PubMed Central

    Wu, J. H.; Jia, Q.

    2016-01-01

    The occurrence of extreme events and critical phenomena is of importance because they can have inquisitive scientific impact and profound socio-economic consequences. Here we show a universal mechanism describing extreme events along with critical phenomena and derive a general expression of the probability distribution without concerning the physical details of individual events or critical properties. The general probability distribution unifies most important distributions in the field and demonstrates improved performance. The shape and symmetry of the general distribution is determined by the parameters of the fluctuations. Our work sheds judicious insights into the dynamical processes of complex systems with practical significance and provides a general approach of studying extreme and critical episodes in a combined and multidisciplinary scheme. PMID:26880219

  20. Information modeling of fundamental phenomena in digital electronic imaging systems

    NASA Astrophysics Data System (ADS)

    Jakubik, Petr; Pospisil, Jaroslav

    2003-11-01

    This article contains basic theoretical results of mathematical interpretations of some fundamental phenomena in the modern digital electronic imaging systems with pixel photodetection structure mainly from the standpoint of the mean mutual information. For such a purpose, the mentioned systems are approximated by a suitable linear and isoplanatic signal transfer model of a two-dimensional stationary and ergodic continuous stochastic distribution of the object scene- light intensity which is limited in size by the input field of view. The treated mathematical modelling of the presented phenomena is based on utilizing the continuous linear signal transfer theory and the extended modem communication and information theory for the spectral domain of spatial frequencies, especially. The presented equations are acceptable for an analysis and optimal synthesis of digital electronic imaging systems fidfilling the proposed signal transfer model. These systems give conventionally a better information efficiency and image quality in comparison with the older analog imaging systems.

  1. Purcell effect and Lamb shift as interference phenomena.

    PubMed

    Rybin, Mikhail V; Mingaleev, Sergei F; Limonov, Mikhail F; Kivshar, Yuri S

    2016-01-01

    The Purcell effect and Lamb shift are two well-known physical phenomena which are usually discussed in the context of quantum electrodynamics, with the zero-point vibrations as a driving force of those effects in the quantum approach. Here we discuss the classical counterparts of these quantum effects in photonics, and explain their physics trough interference wave phenomena. As an example, we consider a waveguide in a planar photonic crystal with a side-coupled defect, and demonstrate a perfect agreement between the results obtained on the basis of quantum and classic approaches and reveal their link to the Fano resonance. We find that in such a waveguide-cavity geometry the Purcell effect can modify the lifetime by at least 25 times, and the Lamb shift can exceed 3 half-widths of the cavity spectral line. PMID:26860195

  2. A review of anode phenomena in vacuum arces

    SciTech Connect

    Miller, H.C.

    1988-09-01

    This report discusses arc modes at the anode, experimental results pertinent to anode phenomena, and theoretical explanations of anode phenomena. The dominant mechanism controlling the formation of an anode spot appears to depend upon the electrode geometry, the electrode material, and the current waveforms of the particular vacuum arc being considered. In specific experimental conditions, either magnetic constriction in the gap plasma or gross anode melting or local anode evaporation can trigger the transition. However, the most probable explanation of anode spot formation is a combination theory, which considers magnetic constriction in the plasma together with the fluxes of material from the anode and cathode as well as the thermal, electrical, and geometric effects of the anode in analyzing the behavior of the anode and the nearby plasma. 88 refs., 6 figs., 8 tabs.

  3. Concepts and methods for describing critical phenomena in fluids

    NASA Technical Reports Server (NTRS)

    Sengers, J. V.; Sengers, J. M. H. L.

    1977-01-01

    The predictions of theoretical models for a critical-point phase transistion in fluids, namely the classical equation with third-degree critical isotherm, that with fifth-degree critical isotherm, and the lattice gas, are reviewed. The renormalization group theory of critical phenomena and the hypothesis of universality of critical behavior supported by this theory are discussed as well as the nature of gravity effects and how they affect cricital-region experimentation in fluids. The behavior of the thermodynamic properties and the correlation function is formulated in terms of scaling laws. The predictions of these scaling laws and of the hypothesis of universality of critical behavior are compared with experimental data for one-component fluids and it is indicated how the methods can be extended to describe critical phenomena in fluid mixtures.

  4. Phenomena associated with magma expansion into a drift

    SciTech Connect

    Gaffney, E. S.

    2002-01-01

    One of the significant threats to the proposed Yucca Mountain nuclear waste repository has been identified as the possibility of intersection of the underground structure by a basaltic intrusion. Based on the geology of the region, it is assumed that such an intrusion would consist of an alkali basalt similar to the nearby Lathrop Wells cone, which has been dated at about 78 ka. The threat of radioactive release may be either from eruption through the surface above the repository of basalt that had been contaminated or from migration through ground water of radionucleides released as a result of damage to waste packages that interact with the magma. As part of our study of these threats, we are analyzing the phenomena associated with magma expansion into drifts in tuff. The early phenomena of the encounter of volatile-rich basaltic magma with a drift are discussed here.

  5. Scaling relations and multicritical phenomena from functional renormalization.

    PubMed

    Boettcher, Igor

    2015-06-01

    We investigate multicritical phenomena in O(N)+O(M) models by means of nonperturbative renormalization group equations. This constitutes an elementary building block for the study of competing orders in a variety of physical systems. To identify possible multicritical points in phase diagrams with two ordered phases, we compute the stability of isotropic and decoupled fixed point solutions from scaling potentials of single-field models. We verify the validity of Aharony's scaling relation within the scale-dependent derivative expansion of the effective average action. We discuss implications for the analysis of multicritical phenomena with truncated flow equations. These findings are an important step towards studies of competing orders and multicritical quantum phase transitions within the framework of functional renormalization. PMID:26172666

  6. Small Is Different: Emergent Phenomena at the Nonscalable Size Regime

    NASA Astrophysics Data System (ADS)

    Landman, Uzi

    2009-11-01

    When the scale of materials structures is reduced to the nanoscale, emergent physical and chemical behavior often occurs, that is not commonly expected, or deduced, from knowledge learned at larger sizes. Such new behavior may be found when the size of the interrogated physical system becomes comparable to a phenomena-dependent characteristic length-scale; for example, the width of a quantum wire approaches the Fermi wave- length of the conducting electrons, or the dimensions of a liquid bridge, or a nanojet, approach the wave-length of a hydrodynamical instability underlying collapse or droplet ejection. Using computer-based simulations we highlight and discuss such emergent phenomena. Systems that we discuss include: electrons in 2D semiconductor quantum dots, nanoscale junctions, liquid bridges and jets, and interfacial control of the chemical catalytic properties of surface-supported gold nanoclusters.

  7. Scaling relations and multicritical phenomena from functional renormalization

    NASA Astrophysics Data System (ADS)

    Boettcher, Igor

    2015-06-01

    We investigate multicritical phenomena in O (N )+O (M ) models by means of nonperturbative renormalization group equations. This constitutes an elementary building block for the study of competing orders in a variety of physical systems. To identify possible multicritical points in phase diagrams with two ordered phases, we compute the stability of isotropic and decoupled fixed point solutions from scaling potentials of single-field models. We verify the validity of Aharony's scaling relation within the scale-dependent derivative expansion of the effective average action. We discuss implications for the analysis of multicritical phenomena with truncated flow equations. These findings are an important step towards studies of competing orders and multicritical quantum phase transitions within the framework of functional renormalization.

  8. Autoscopic phenomena and one's own body representation in dreams.

    PubMed

    Occhionero, Miranda; Cicogna, Piera Carla

    2011-12-01

    Autoscopic phenomena (AP) are complex experiences that include the visual illusory reduplication of one's own body. From a phenomenological point of view, we can distinguish three conditions: autoscopic hallucinations, heautoscopy, and out-of-body experiences. The dysfunctional pattern involves multisensory disintegration of personal and extrapersonal space perception. The etiology, generally either neurological or psychiatric, is different. Also, the hallucination of Self and own body image is present during dreams and differs according to sleep stage. Specifically, the representation of the Self in REM dreams is frequently similar to the perception of Self in wakefulness, whereas in NREM dreams, a greater polymorphism of Self and own body representation is observed. The parallels between autoscopic phenomena in pathological cases and the Self-hallucination in dreams will be discussed to further the understanding of the particular states of self awareness, especially the complex integration of different memory sources in Self and body representation. PMID:21316265

  9. A universal mechanism of extreme events and critical phenomena.

    PubMed

    Wu, J H; Jia, Q

    2016-01-01

    The occurrence of extreme events and critical phenomena is of importance because they can have inquisitive scientific impact and profound socio-economic consequences. Here we show a universal mechanism describing extreme events along with critical phenomena and derive a general expression of the probability distribution without concerning the physical details of individual events or critical properties. The general probability distribution unifies most important distributions in the field and demonstrates improved performance. The shape and symmetry of the general distribution is determined by the parameters of the fluctuations. Our work sheds judicious insights into the dynamical processes of complex systems with practical significance and provides a general approach of studying extreme and critical episodes in a combined and multidisciplinary scheme. PMID:26880219

  10. ESM of Ionic and Electrochemical Phenomena on the Nanoscale

    SciTech Connect

    Kalinin, Sergei V; Kumar, Amit; Balke, Nina; McCorkle, Morgan L; Guo, Senli; Arruda, Thomas M; Jesse, Stephen

    2011-01-01

    Operation of energy storage and conversion devices is ultimately controlled by series of intertwined ionic and electronic transport processes and electrochemical reactions at surfaces and interfaces, strongly mediated by strain and mechanical processes [1-4]. In a typical fuel cell, these include chemical species transport in porous cathode and anode materials, gas-solid electrochemical reactions at grains and triple-phase boundaries (TPBs), ionic and electronic flows in multicomponent electrodes, and chemical and electronic potential drops at internal interfaces in electrodes and electrolytes. All these phenomena are sensitively affected by the microstructure of materials from device level to the atomic scales as illustrated in Fig. 1. Similar spectrum of length scales and phenomena underpin operation of other energy systems including primary and secondary batteries, as well as hybrid systems such flow and metal-air/water batteries.

  11. Sixth Microgravity Fluid Physics and Transport Phenomena Conference Abstracts

    NASA Technical Reports Server (NTRS)

    Singh, Bhim (Compiler)

    2002-01-01

    The Sixth Microgravity Fluid Physics and Transport Phenomena Conference provides the scientific community the opportunity to view the current scope of the Microgravity Fluid Physics and Transport Phenomena Program, current research opportunities, and plans for the near future. The conference focuses not only on fundamental research but also on applications of this knowledge towards enabling future space exploration missions. A whole session dedicated to biological fluid physics shows increased emphasis that the program has placed on interdisciplinary research. The conference includes invited plenary talks, technical paper presentations, poster presentations, and exhibits. This TM is a compilation of abstracts of the papers and the posters presented at the conference. Web-based proceedings, including the charts used by the presenters, will be posted on the web shortly after the conference.

  12. Properties of satellite orbits - Ephemerides, dynamical constants, and satellite phenomena

    NASA Technical Reports Server (NTRS)

    Aksnes, K.

    1977-01-01

    A short account is given of the history of the observation of the Galilean satellites, with an emphasis on early orbital work and practical applications thereof to world mapping and navigation. The general character of satellite motion is described from a geometric and physical point of view without reference to mathematics. This is followed by a similar discussion of ordinary and mutual satellite phenomena. The accuracies of published ephemerides are discussed on the basis of the observations and theories available for the various satellites. The ephemeris tables need to be revised and, perhaps, partly replaced by well-documented computer programs. The determination of physical parameters (planetary masses and oblatenesses; masses, sizes, and albedo maps of satellites) from positional observations of satellites and photometric observations of ordinary and mutual satellite phenomena is discussed.

  13. Protein Crystallization: Specific Phenomena and General Insights on Crystallization Kinetics

    NASA Technical Reports Server (NTRS)

    Rosenberger, F.

    1998-01-01

    Experimental and simulation studies of the nucleation and growth kinetics of proteins have revealed phenomena that are specific for macromolecular crystallization, and others that provide a more detailed understanding of solution crystallization in general. The more specific phenomena, which include metastable liquid-liquid phase separations and gelation prior to solid nucleation, are due to the small ratio of the intermolecular interaction-range to the size of molecules involved. The apparently more generally applicable mechanisms include the cascade-like formation of macrosteps, as an intrinsic morphological instability that roots in the coupled bulk transport and nonlinear interface kinetics in systems with mixed growth rate control. Analyses of this nonlinear response provide (a) criteria for the choice of bulk transport conditions to minimize structural defect formation, and (b) indications that the "slow" protein crystallization kinetics stems from the mutual retardation of growth steps.

  14. Stochastic Car-Following Model for Explaining Nonlinear Traffic Phenomena

    NASA Astrophysics Data System (ADS)

    Meng, Jianping; Song, Tao; Dong, Liyun; Dai, Shiqiang

    There is a common time parameter for representing the sensitivity or the lag (response) time of drivers in many car-following models. In the viewpoint of traffic psychology, this parameter could be considered as the perception-response time (PRT). Generally, this parameter is set to be a constant in previous models. However, PRT is actually not a constant but a random variable described by the lognormal distribution. Thus the probability can be naturally introduced into car-following models by recovering the probability of PRT. For demonstrating this idea, a specific stochastic model is constructed based on the optimal velocity model. By conducting simulations under periodic boundary conditions, it is found that some important traffic phenomena, such as the hysteresis and phantom traffic jams phenomena, can be reproduced more realistically. Especially, an interesting experimental feature of traffic jams, i.e., two moving jams propagating in parallel with constant speed stably and sustainably, is successfully captured by the present model.

  15. High spatial resolution measurements of ram accelerator gas dynamic phenomena

    NASA Technical Reports Server (NTRS)

    Hinkey, J. B.; Burnham, E. A.; Bruckner, A. P.

    1992-01-01

    High spatial resolution experimental tube wall pressure measurements of ram accelerator gas dynamic phenomena are presented. The projectile resembles the centerbody of a ramjet and travels supersonically through a tube filled with a combustible gaseous mixture, with the tube acting as the outer cowling. Pressure data are recorded as the projectile passes by sensors mounted in the tube wall at various locations along the tube. Data obtained by using a special highly instrumented section of tube has allowed the recording of gas dynamic phenomena with a spatial resolution on the order of one tenth the projectile length. High spatial resolution tube wall pressure data from the three regimes of propulsion studied to date (subdetonative, transdetonative, and superdetonative) are presented and reveal the 3D character of the flowfield induced by projectile fins and the canting of the projectile body relative to the tube wall. Also presented for comparison to the experimental data are calculations made with an inviscid, 3D CFD code.

  16. The function of nonlinear phenomena in meerkat alarm calls.

    PubMed

    Townsend, Simon W; Manser, Marta B

    2011-02-23

    Nonlinear vocal phenomena are a ubiquitous feature of human and non-human animal vocalizations. Although we understand how these complex acoustic intrusions are generated, it is not clear whether they function adaptively for the animals producing them. One explanation is that nonlinearities make calls more unpredictable, increasing behavioural responses and ultimately reducing the chances of habituation to these call types. Meerkats (Suricata suricatta) exhibit nonlinear subharmonics in their predator alarm calls. We specifically tested the 'unpredictability hypothesis' by playing back naturally occurring nonlinear and linear medium-urgency alarm call bouts. Results indicate that subjects responded more strongly and foraged less after hearing nonlinear alarm calls. We argue that these findings support the unpredictability hypothesis and suggest this is the first study in animals or humans to show that nonlinear vocal phenomena function adaptively. PMID:20659926

  17. Tank Pressure Control Experiment/thermal Phenomena (TPCE/TP)

    NASA Technical Reports Server (NTRS)

    Hasan, M. M.; Knoll, R. H.

    1992-01-01

    The 'Tank Pressure Control Experiment/Thermal Phenomena (TPCE/TP)' is a reflight of the tank pressure control experiment (TPCE), flown on STS-43 in a standard Get-Away Special (GAS) container in August 1991. The TPCE obtained extensive video and digital data of the jet induced mixing process in a partially filled tank in low gravity environments. It also provided limited data on the thermal processes involved. The primary objective of the reflight of TPCE is to investigate experimentally the phenomena of liquid superheating and pool nucleate boiling at very low heat fluxes in a long duration low gravity environment. The findings of this experiment will be of direct relevance to space based subcritical cryogenic fluid system design and operation. Experiment hardware and results from the first TPCE are described in outline and graphic form.

  18. Purcell effect and Lamb shift as interference phenomena

    PubMed Central

    Rybin, Mikhail V.; Mingaleev, Sergei F.; Limonov, Mikhail F.; Kivshar, Yuri S.

    2016-01-01

    The Purcell effect and Lamb shift are two well-known physical phenomena which are usually discussed in the context of quantum electrodynamics, with the zero-point vibrations as a driving force of those effects in the quantum approach. Here we discuss the classical counterparts of these quantum effects in photonics, and explain their physics trough interference wave phenomena. As an example, we consider a waveguide in a planar photonic crystal with a side-coupled defect, and demonstrate a perfect agreement between the results obtained on the basis of quantum and classic approaches and reveal their link to the Fano resonance. We find that in such a waveguide-cavity geometry the Purcell effect can modify the lifetime by at least 25 times, and the Lamb shift can exceed 3 half-widths of the cavity spectral line. PMID:26860195

  19. Aviation Safety Program Atmospheric Environment Safety Technologies (AEST) Project

    NASA Technical Reports Server (NTRS)

    Colantonio, Ron

    2011-01-01

    Engine Icing: Characterization and Simulation Capability: Develop knowledge bases, analysis methods, and simulation tools needed to address the problem of engine icing; in particular, ice-crystal icing Airframe Icing Simulation and Engineering Tool Capability: Develop and demonstrate 3-D capability to simulate and model airframe ice accretion and related aerodynamic performance degradation for current and future aircraft configurations in an expanded icing environment that includes freezing drizzle/rain Atmospheric Hazard Sensing and Mitigation Technology Capability: Improve and expand remote sensing and mitigation of hazardous atmospheric environments and phenomena

  20. Lower Atmospheric Boundary Layer Experiment (LABLE) Final Campaign Report

    SciTech Connect

    Klein, P; Bonin, TA; Newman, JF; Turner, DD; Chilson, P; Blumberg, WG; Mishra, S; Wainwright, CE; Carney, M; Jacobsen, EP; Wharton, S

    2015-11-01

    The Lower Atmospheric Boundary Layer Experiment (LABLE) included two measurement campaigns conducted at the Atmospheric Radiation Measurement (ARM) Southern Great Plains site in Oklahoma during 2012 and 2013. LABLE was designed as a multi-phase, low-cost collaboration among the University of Oklahoma, the National Severe Storms Laboratory, Lawrence Livermore National Laboratory, and the ARM program. A unique aspect was the role of graduate students in LABLE. They served as principal investigators and took the lead in designing and conducting experiments using different sampling strategies to best resolve boundary-layer phenomena.

  1. The effects of meteoroids on the Earth atmosphere

    NASA Astrophysics Data System (ADS)

    Popova, Olga

    Each year 108 kg of extraterrestrial material is intercepted by the Earth. The fate of entering meteoroids in atmosphere is determined by their size, velocity and material properties. The range of meteoroids entering the Earth is extremely large; their masses varying from about 10-18 g up to asteroid-class impactors ( 1015 kg). Cosmic bodies entering the Earth' atmosphere lose a part of their mass or even the total mass during the interaction with the atmosphere. Material from ablation of small-sized meteors (roughly 0.01-1 cm) is mostly deposited between 130 and 70 km altitudes. Larger bodies (up to meter sizes) penetrate deeper into the atmosphere (down to 20 km altitude). Meteoroids larger about Tunguska-sized ( 100 m, 109 kg) ones lose only small part of their mass and energy during their passage through the Earth's atmosphere. The chemistry, composition and thermal structure of the atmosphere can be modified by an influx of material from outside. Ionized and luminous areas appear due to meteoroid interaction with the atmosphere. Meteor spectra confirm appearance of Fe, Si, Mg, H, Na, Ca, Ni, Mn, Cr, Al, Ti, CN, FeO, AlO, MgO, OH due to ablation. Meteors are sometimes considered as the source of organic material deposited into the atmosphere during ablation. Meteor phenomena can contribute as a source of nitric oxides in the mesosphere. Meteoric material is involved into the atmospheric chemistry. The ablation of meteoroids in the Earth's atmosphere gives rise to layers of metal atoms between 80 and 110 km that are global in extent. Dust particles in the atmosphere can originate from meteoroid fragmentation, from the recondensation of ablated meteor vapor and from ablated remnants. Small mineral grains provide the major source of condensation nuclei of stratospheric aerosol formation and may be also a constitutent of the global stratospheric aerosol layer. The evidence for extraplanetary material in the atmosphere will be reviewed.

  2. Oscillations in stellar atmospheres

    NASA Technical Reports Server (NTRS)

    Costa, A.; Ringuelet, A. E.; Fontenla, J. M.

    1989-01-01

    Atmospheric excitation and propagation of oscillations are analyzed for typical pulsating stars. The linear, plane-parallel approach for the pulsating atmosphere gives a local description of the phenomenon. From the local analysis of oscillations, the minimum frequencies are obtained for radially propagating waves. The comparison of the minimum frequencies obtained for a variety of stellar types is in good agreement with the observed periods of the oscillations. The role of the atmosphere in the globar stellar pulsations is thus emphasized.

  3. Global Atmospheric Aerosol Modeling

    NASA Technical Reports Server (NTRS)

    Hendricks, Johannes; Aquila, Valentina; Righi, Mattia

    2012-01-01

    Global aerosol models are used to study the distribution and properties of atmospheric aerosol particles as well as their effects on clouds, atmospheric chemistry, radiation, and climate. The present article provides an overview of the basic concepts of global atmospheric aerosol modeling and shows some examples from a global aerosol simulation. Particular emphasis is placed on the simulation of aerosol particles and their effects within global climate models.

  4. Atmospheres from Within

    NASA Technical Reports Server (NTRS)

    Morgan, Thomas; Abshire, James; Clancy, Todd; Fry, Ghee; Gustafson, Bo; Hecht, Michael; Kostiuk, Theodor; Rall, Jonathan; Reuter, Dennis; Sheldon, Robert

    1996-01-01

    In this review of atmospheric investigations from planetary surfaces, a wide variety of measurement and instrument techniques relevant to atmospheric studies from future planetary lander missions are discussed. The diversity of planetary surface environments within the solar system precludes complete or highly specific coverage, but lander investigations for Mars and cometary missions are presented as specific cases that represent the broad range of atmospheric-surface boundaries and that also correspond to high priority goals for future national and international lander missions.

  5. Heliospheric Consecuences of Solar Activity In Several Interplanetary Phenomena

    NASA Astrophysics Data System (ADS)

    Valds-Galicia, J. F.; Mendoza, B.; Lara, A.; Maravilla, D.

    We have done an analysis of several phenomena related to solar activity such as the total magnetic flux, coronal hole area and sunspots, investigated its long trend evolu- tion over several solar cycles and its possible relationships with interplanetary shocks, sudden storm commencements at earth and cosmic ray variations. Our results stress the physical connection between the solar magnetic flux emergence and the interplan- etary medium dynamics, in particular the importance of coronal hole evolution in the structuring of the heliosphere.

  6. Fourth DOE Natural Phenomena Hazards Mitigation Conference: Proceedings. Volume 1

    SciTech Connect

    Not Available

    1993-12-31

    This conference allowed an interchange in the natural phenomena area among designers, safety professionals, and managers. The papers presented in Volume I of the proceedings are from sessions I - VIII which cover the general topics of: DOE standards, lessons learned and walkdowns, wind, waste tanks, ground motion, testing and materials, probabilistic seismic hazards, risk assessment, base isolation and energy dissipation, and lifelines and floods. Individual papers are indexed separately. (GH)

  7. Recent Applications of the Volterra Theory to Aeroelastic Phenomena

    NASA Technical Reports Server (NTRS)

    Silva, Walter A.; Haji, Muhammad R; Prazenica, Richard J.

    2005-01-01

    The identification of nonlinear aeroelastic systems based on the Volterra theory of nonlinear systems is presented. Recent applications of the theory to problems in experimental aeroelasticity are reviewed. These results include the identification of aerodynamic impulse responses, the application of higher-order spectra (HOS) to wind-tunnel flutter data, and the identification of nonlinear aeroelastic phenomena from flight flutter test data of the Active Aeroelastic Wing (AAW) aircraft.

  8. Nonlinear phenomena in the constant electric field in insulation pressboard

    NASA Astrophysics Data System (ADS)

    Rogalski, Przemys?aw

    2015-09-01

    The paper presents the results of DC conductivity dependence of a transformer oil impregnated pressboard, with moisture content of 2.9% by weight, measured for temperature from 20 C to 80 C and a field strength from 10 kV/m to 1000 kV/m. It was found that the non-linear phenomena, which presence cannot be explained by the theory of ion conduction of oil-paper insulation, is intensifying with increase of the electric field strength.

  9. Search for Higgs and new phenomena at colliders

    SciTech Connect

    Lammel, Stephan; /Fermilab

    2006-01-01

    The present status of searches for the Higgs boson(s) and new phenomena is reviewed. The focus is on analyses and results from the current runs of the HERA and Tevatron experiments. The LEP experiments have released their final combined MSSM Higgs results for this conference. Also included are results from sensitivity studies of the LHC experiments and lepton flavor violating searches from the B factories, KEKB and PEP-II.

  10. Possible relationships between solar activity and meteorological phenomena

    NASA Technical Reports Server (NTRS)

    Bandeen, W. R. (Editor); Maran, S. P. (Editor)

    1975-01-01

    A symposium was conducted in which the following questions were discussed: (1) the evidence concerning possible relationships between solar activity and meteorological phenomena; (2) plausible physical mechanisms to explain these relationships; and (3) kinds of critical measurements needed to determine the nature of solar/meteorological relationships and/or the mechanisms to explain them, and which of these measurements can be accomplished best from space.

  11. Interfacial Phenomena: Linking Atomistic and Molecular Level Processes

    SciTech Connect

    Jay A Brandes

    2009-09-23

    This was a grant to support travel for scientists to present data and interact with others in their field. Specifically, speakers presented their data in a session entitled Interfacial Phenomena: Linking Atomistic and Macroscopic Properties: Theoretical and Experimental Studies of the Structure and Reactivity of Mineral Surfaces. The session ran across three day periods, March 30-31 2004. The sessions organizers were David J. Wesolowski andGordon E. Brown Jr. There were a total of 30 talks presented.

  12. Seismically-induced sloshing phenomena in LMFBR reactor tanks

    SciTech Connect

    Ma, D.C.; Liu, W.K.; Gvildys, J.; Chang, Y.W.

    1982-01-01

    A coupled fluid-structure interaction solution procedure for analyzing seismically-induced sloshing phenomena in fluid-tank systems is presented. Both rigid and flexible tanks are considered. Surface-wave effects are also included. Results demonstrate that tank flexibility could affect the free surface-wave amplitude and the sloshing pressuare if the natural frequency of the fluid-structure system is below 5 Hz. Furthermore, the presence of higher sloshing modes do enhance the post-earthquake sloshing response.

  13. Pain phenomena and possible mechanisms in patients with painful polyneuropathy.

    PubMed

    Otto, Marit; Bak, Sren; Bach, Flemming W; Jensen, Troels S; Sindrup, Sren H

    2003-01-01

    Painful polyneuropathy is a common neuropathic pain condition characterized by different typical pain phenomena and symptoms. The present study determined the frequency of pain phenomena and signs in painful polyneuropathy, and compared the symptomatology in patients with signs of increased small fiber response with that in patients with signs of deafferentation. Eighty-one consecutive patients with painful polyneuropathy were studied. The most common pain phenomena were deep aching pain (88%) and pain on pressure (69%), followed by pain paroxysms (59%) and less frequently pain on light touch (31%). Patients with increased cold and heat detection thresholds were more likely to have pain paroxysms (odds ratio (OR) 2.5 and 5.2) and patients with pain summation on repetitive mechanical stimulation more often had touch-evoked pain (OR=4.0) than patients without these phenomena. Findings compatible with increased small fiber response were found in six patients (7.4%), in 41 (50.6%) unequivocal signs of deafferentation were found, and 34 patients (42%) could not be classified. There was no significant difference in presenting symptoms between these groups. In conclusion, in painful polyneuropathy, (1). deep aching pain is the most frequently reported pain symptom; (2). the association between pain paroxysms with decreased small fiber function and touch-evoked pain with abnormal pain summation on mechanical stimulation indicate that central nervous system mechanisms are responsible for these symptoms; (3). sensitized small fibers as the single mechanism of pain is rare; and (4). pain symptomatology cannot predict pain mechanisms as being mainly deafferentation or sensitized small fibers. PMID:12507713

  14. Analysis of phase distribution phenomena in microgravity environments

    NASA Technical Reports Server (NTRS)

    Lahey, Richard T., Jr.; Bonetto, F.

    1994-01-01

    The purpose of the research presented in this paper is to demonstrate the ability of multidimensional two-fluid models for bubbly two-phase flow to accurately predict lateral phase distribution phenomena in microgravity environments. If successful, this research should provide NASA with mechanistically-based analytical methods which can be used for multiphase space system design and evaluation, and should be the basis for future shuttle experiments for model verification.

  15. Reduced Order Models for Fluid-Structure Interaction Phenomena

    NASA Astrophysics Data System (ADS)

    Gallardo, Daniele

    With the advent of active flow control devices for regulating the structural responses of systems involving fluid-structure interaction phenomena, there is a growing need of efficient models that can be used to control the system. The first step is then to be able to model the system in an efficient way based on reduced-order models. This is needed so that accurate predictions of the system evolution could be performed in a fast manner, ideally in real time. However, existing reduced-order models of fluid-structure interaction phenomena that provide closed-form solutions are applicable to only a limited set of scenarios while for real applications high-fidelity experiments or numerical simulations are required, which are unsuitable as efficient or reduced-order models. This thesis proposes a novel reduced-order and efficient model for fluid-structure interaction phenomena. The model structure employed is such that it is generic for different fluid-structure interaction problems. Based on this structure, the model is first built for a given fluid-structure interaction problem based on a database generated through high-fidelity numerical simulations while it can subsequently be used to predict the structural response over a wide set of flow conditions for the fluid-structure interaction problem at hand. The model is tested on two cases: a cylinder suspended in a low Reynolds number flow that includes the lock-in region and an airfoil subjected to plunge oscillations in a high Reynolds number regime. For each case, in addition to training profile we also present validation profiles that are used to determine the performance of the reduced-order model. The reduced-order model devised in this study proved to be an effective and efficient modeling method for fluid-structure interaction phenomena and it shown its applicability in very different kind of scenarios.

  16. Dynamic critical phenomena in the AdS/CFT duality

    SciTech Connect

    Maeda, Kengo; Natsuume, Makoto; Okamura, Takashi

    2008-11-15

    In critical phenomena, singular behaviors arise not only for thermodynamic quantities but also for transport coefficients. We study this dynamic critical phenomenon in the AdS/CFT duality. We consider black holes with a single R-charge in various dimensions and compute the R-charge diffusion in the linear perturbations. In this case, the black holes belong to model B according to the classification of Hohenberg and Halperin.

  17. The role of spinning electrons in paramagnetic phenomena

    NASA Technical Reports Server (NTRS)

    Bose, D. M.

    1986-01-01

    An attempt is made to explain paramagnetic phenomena without assuming the orientation of a molecule or ion in a magnetic field. Only the spin angular momentum is assumed to be responsible. A derivative of the Gurie-Langevin law and the magnetic moments of ions are given as a function of the number of electrons in an inner, incomplete shell. An explanation of Gerlach's experiments with iron and nickel vapors is attempted. An explanation of magnetomechanical experiments with ferromagne elements is given.

  18. Draft tube flow phenomena across the bulb turbine hill chart

    NASA Astrophysics Data System (ADS)

    Duquesne, P.; Fraser, R.; Maciel, Y.; Aeschlimann, V.; Deschênes, C.

    2014-03-01

    In the framework of the BulbT project launched by the Consortium on Hydraulic Machines and the LAMH (Hydraulic Machine Laboratory of Laval University) in 2011, an intensive campaign to identify flow phenomena in the draft tube of a model bulb turbine has been done. A special focus was put on the draft tube component since it has a particular importance for recuperation in low head turbines. Particular operating points were chosen to analyse flow phenomena in this component. For each of these operating points, power, efficiency and pressure were measured following the IEC 60193 standard. Visualizations, unsteady wall pressure and efficiency measurements were performed in this component. The unsteady wall pressure was monitored at seven locations in the draft tube. The frequency content of each pressure signal was analyzed in order to characterize the flow phenomena across the efficiency hill chart. Visualizations were recorded with a high speed camera using tufts and cavitation bubbles as markers. The predominant detected phenomena were mapped and categorized in relation to the efficiency hill charts obtained for three runner blade openings. At partial load, the vortex rope was detected and characterized. An inflection in the partial load efficiency curves was found to be related to complex vortex rope instabilities. For overload conditions, the efficiency curves present a sharp drop after the best efficiency point, corresponding to an inflection on the power curves. This break off is more severe towards the highest blade openings. It is correlated to a flow separation at the wall of the draft tube. Also, due to the separation occurring in these conditions, a hysteresis effect was observed on the efficiency curves.

  19. Dynamical system analysis of unstable flow phenomena in centrifugal blower

    NASA Astrophysics Data System (ADS)

    Garcia, David; Stickland, Matthew; Li?kiewicz, Grzegorz

    2015-09-01

    Methods of dynamical system analysis were employed to analyze unsteady phenomena in a centrifugal blower. Pressure signals gathered at different control points were decomposed into their Principal Components (PCs) by means of Singular Spectrum Analysis (SSA). Certain number of PCs was considered in the analysis based on their statistical correlation. Projection of the original signal onto its PCs allowed to draw the phase trajectory that clearly separated non-stable blower working conditions from its regular operation.

  20. The hard start phenomena in hypergolic engines. Volume 1: Bibliography

    NASA Technical Reports Server (NTRS)

    Miron, Y.; Perlee, H. E.

    1974-01-01

    A bibliography of reports pertaining to the hard start phenomenon in attitude control rocket engines on Apollo spacecraft is presented. Some of the subjects discussed are; (1) combustion of hydrazine, (2) one dimensional theory of liquid fuel rocket combustion, (3) preignition phenomena in small pulsed rocket engines, (4) experimental and theoretical investigation of the fluid dynamics of rocket combustion, and (5) nonequilibrium combustion and nozzle flow in propellant performance.

  1. Obsessional phenomena and the development of imaginative competence.

    PubMed

    Holmes, J

    1982-06-01

    Obsessional phenomena are discussed in the light of anxieties arising around the ages 8-12. Three cases of the disappearance of obsessional symptoms are then described. In one remarkable sequence of dreams preceded recovery; in another it was the establishment of a secure therapeutic bond; in the third it was falling in love. The capacity securely to differentiate between fantasy and reality is seen as an essential development element in the recovery from obsessionality. PMID:7104245

  2. Superfluous neuroscience information makes explanations of psychological phenomena more appealing.

    PubMed

    Fernandez-Duque, Diego; Evans, Jessica; Christian, Colton; Hodges, Sara D

    2015-05-01

    Does the presence of irrelevant neuroscience information make explanations of psychological phenomena more appealing? Do fMRI pictures further increase that allure? To help answer these questions, 385 college students in four experiments read brief descriptions of psychological phenomena, each one accompanied by an explanation of varying quality (good vs. circular) and followed by superfluous information of various types. Ancillary measures assessed participants' analytical thinking, beliefs on dualism and free will, and admiration for different sciences. In Experiment 1, superfluous neuroscience information increased the judged quality of the argument for both good and bad explanations, whereas accompanying fMRI pictures had no impact above and beyond the neuroscience text, suggesting a bias that is conceptual rather than pictorial. Superfluous neuroscience information was more alluring than social science information (Experiment 2) and more alluring than information from prestigious "hard sciences" (Experiments 3 and 4). Analytical thinking did not protect against the neuroscience bias, nor did a belief in dualism or free will. We conclude that the "allure of neuroscience" bias is conceptual, specific to neuroscience, and not easily accounted for by the prestige of the discipline. It may stem from the lay belief that the brain is the best explanans for mental phenomena. PMID:25390208

  3. Assessing Decreased Sensation and Increased Sensory Phenomena in Diabetic Polyneuropathies

    PubMed Central

    Herrmann, David N.; Staff, Nathan P.; Dyck, P. James B.

    2013-01-01

    Loss of sensation and increased sensory phenomena are major expressions of varieties of diabetic polyneuropathies needing improved assessments for clinical and research purposes. We provide a neurobiological explanation for the apparent paradox between decreased sensation and increased sensory phenomena. Strongly endorsed is the use of the 10-g monofilaments for screening of feet to detect sensation loss, with the goal of improving diabetic management and prevention of foot ulcers and neurogenic arthropathy. We describe improved methods to assess for the kind, severity, and distribution of both large- and small-fiber sensory loss and which approaches and techniques may be useful for conducting therapeutic trials. The abnormality of attributes of nerve conduction may be used to validate the dysfunction of large sensory fibers. The abnormality of epidermal nerve fibers/1 mm may be used as a surrogate measure of small-fiber sensory loss but appear not to correlate closely with severity of pain. Increased sensory phenomena are recognized by the characteristic words patients use to describe them and by the severity and persistence of these symptoms. Tests of tactile and thermal hyperalgesia are additional markers of neural hyperactivity that are useful for diagnosis and disease management. PMID:24158999

  4. Shumann resonances and electromagnetic transparence in the atmosphere of Titan

    NASA Astrophysics Data System (ADS)

    Molina-Cuberos, G. J.; Porti, J.; Besser, B. P.; Morente, J. A.; Margineda, J.; Lichtenegger, H. I. M.; Salinas, A.; Schwingenschuh, K.; Eichelberger, H. U.

    2004-01-01

    Among the multiple questions that the CASSINI/HUYGENS mission tries to answer is the likelihood of electric discharges in Titan's atmosphere. The instruments ``Huygens Atmospheric Structure Instrument'' and ``Radio and Plasma Wave Science'' will probe the electromagnetic emissions during the Huygens descent and Cassini flybys, respectively. Although no lightning was observed during Voyager's encounters with Titan in 1980 and 1981, this does not exclude the existence of lightning phenomena. Recent investigations show that lightning discharges could occur in the lower atmosphere, such as the detection of methane condensation clouds in the troposphere and the theoretical prediction of an electric field that would be sufficient enough to cause lightning. We present a numerical model of Titan's atmosphere with the aim of calculating the resonance frequencies and the atmospheric transparency to electromagnetic waves. The detection and measurement of these resonances, Schumann frequencies, by the Huygens probe, would show the existence of electric activity connected with lightning discharges in the atmosphere. As it happens with the Schumann frequencies of Earth, losses associated with the electric conductivity will make these frequencies to be lower than the theoretically predicted, the fundamental one being located between 11 and 15 Hz. An analytical study shows that the strong losses associated with the high conductivity make it impossible that an electromagnetic wave generated near the surface with a frequency of 10 MHz or lower reaches the outer part of Titan's atmosphere. Therefore the detection of electromagnetic waves coming from Titan's lower atmosphere by the RPWS instrument is very unlikely.

  5. Spatial reorganization of SST anomalies by stationary atmospheric waves

    NASA Astrophysics Data System (ADS)

    Nilsson, Johan

    2001-08-01

    The dynamics of sea surface temperature (SST) anomalies that force stationary atmospheric waves, which in turn, feed back on the SST field is addressed. The phenomena is isolated by analyzing the dynamics of a slab ocean that is thermally coupled to an atmospheric model. Particular emphasis is put on identifying SST structures that are weakly damped by the joint effect of air-sea heat transfer and atmospheric wave dynamics. A frame work is presented that singles out long-lived SST features in a slab ocean coupled to an arbitrary linear atmospheric model. It is demonstrated that an SST anomaly eventually disintegrates into a number of propagating wave packets. The wave packets are confined in a Gaussian envelope, and each packet is tied to a stationary wave of a particular wavelength. These structures are a manifestation of coupled SST-atmosphere mode, for which the atmosphere and the ocean nearly are in thermal equilibrium. However, a small disequilibrium causes the wave packet to propagate and to broaden in an apparent diffusive manner. Central ideas pertaining to the mid-latitude SST dynamics are illustrated by analyzing the thermal feedback between a two-level atmospheric model (on a β-plane) and a dynamically passive slab ocean. The relevance of the present idealized coupled-modes to the SST variability in the mid-latitudes and in atmospheric GCMs coupled to slab oceans is discussed.

  6. The Mars atmosphere as seen from Curiosity

    NASA Astrophysics Data System (ADS)

    Mischna, Michael

    Study of the Mars atmosphere by the Mars Science Laboratory (MSL) has been ongoing since immediately after landing on August 6, 2012 (UTC) at the bottom of Gale Crater. The MSL Rover Environmental Monitoring Station (REMS) has been the primary payload for atmospheric monitoring, while additional observations from the ChemCam, Mastcam, Navcam and Sample Analysis at Mars (SAM) instruments have augmented our understanding of the local martian environment at Gale. The REMS instrument consists of six separate sensor types, observing air and ground temperature, near-surface winds, relative humidity, surface pressure and UV radiation. The standard cadence of REMS observations consists of five-minute observations of 1 Hz frequency at the top of each hour, augmented by several one-hour extended blocks each sol, also at 1 Hz frequency, together yielding one of the most richly diverse and detailed samplings of the martian atmosphere. Among the intriguing atmospheric phenomena observed during the first 359 sols of the mission is a substantially greater (12% of the diurnal mean) diurnal pressure cycle than found in previous surface measurements by Viking at a similar season (3-4%), likely due to the topography of the crater environment. Measurements of air and ground temperature by REMS are seen to reflect both changes in atmospheric opacity as well as transitions in the surface geology (and surface thermal properties) along the rovers traverse. The REMS UV sensor has provided the first measurements of ultraviolet flux at the martian surface, and identified dust events that reduce solar insolation at the surface. The REMS RH sensor has observed a seasonal change in humidity in addition to the expected diurnal variations in relative humidity; however, no surface frost has been detected through the first 360 sols of the mission. With a weekly cadence, Navcam images the local zenith for purposes of tracking cloud motion and wind direction, and likewise observes the horizon to search (thus far unsuccessfully) for visible dust devil activity. The Mastcam operates with a similar observing frequency for quantifying atmospheric opacity, while ChemCam is used in its passive mode, while pointed at the sky, to measure atmospheric water vapor abundance. Lastly, the SAM suite has provided information about atmospheric composition, including trace species abundances and isotopic ratios, which may be used to infer the history and evolution of the martian atmosphere.

  7. Photochemistry of planetary atmospheres. [Mars atmospheric composition

    NASA Technical Reports Server (NTRS)

    Stief, L. J.

    1973-01-01

    The atmospheric composition of Mars is presented, and the applicability of laboratory data on CO2 absorption cross sections and quantum yields of dissociation is discussed. A summary and critical evaluation are presented on the various mechanisms proposed for converting the photodissociation products CO and O2 back to CO2.

  8. Lithosphere-Atmosphere coupling: Spectral element modeling of the evolution of acoustic waves in the atmosphere from an underground source.

    NASA Astrophysics Data System (ADS)

    Averbuch, Gil; Price, Colin

    2015-04-01

    Lithosphere-Atmosphere coupling: Spectral element modeling of the evolution of acoustic waves in the atmosphere from an underground source. G. Averbuch, C. Price Department of Geosciences, Tel Aviv University, Israel Infrasound is one of the four Comprehensive Nuclear-Test Ban Treaty technologies for monitoring nuclear explosions. This technology measures the acoustic waves generated by the explosions followed by their propagation through the atmosphere. There are also natural phenomena that can act as an infrasound sources like sprites, volcanic eruptions and earthquakes. The infrasound waves generated from theses phenomena can also be detected by the infrasound arrays. In order to study the behavior of these waves, i.e. the physics of wave propagation in the atmosphere, their evolution and their trajectories, numerical methods are required. This presentation will deal with the evolution of acoustic waves generated by underground sources (earthquakes and underground explosions). A 2D Spectral elements formulation for lithosphere-atmosphere coupling will be presented. The formulation includes the elastic wave equation for the seismic waves and the momentum, mass and state equations for the acoustic waves in a moving stratified atmosphere. The coupling of the two media is made by boundary conditions that ensures the continuity of traction and velocity (displacement) in the normal component to the interface. This work has several objectives. The first is to study the evolution of acoustic waves in the atmosphere from an underground source. The second is to derive transmission coefficients for the energy flux with respect to the seismic magnitude and earth density. The third will be the generation of seismic waves from acoustic waves in the atmosphere. Is it possible?

  9. Clouds in Planetary Atmospheres

    NASA Astrophysics Data System (ADS)

    West, R.; Murdin, P.

    2000-11-01

    What are clouds? The answer to that question is both obvious and subtle. In the terrestrial atmosphere clouds are familiar as vast collections of small water drops or ice crystals suspended in the air. In the atmospheres of Venus, Mars, Jupiter, Saturn, Saturn's moon Titan, Uranus, Neptune, and possibly Pluto, they are composed of several other substances including sulfuric acid, ammonia, hydroge...

  10. Exploring Hot Neptune Atmospheres

    NASA Astrophysics Data System (ADS)

    Fortney, Jonathan; Marley, Mark; Saumon, Didier

    2008-03-01

    The first transiting 'hot Neptune'' GJ 436b inhabits an entirely new region of phase space for extrasolar planetary atmospheres. This relatively cool, low-mass object should be the first transiting extrasolar planet to sport a methane-rich atmosphere. Like Uranus and Neptune it may also have an atmosphere highly enriched in heavy elements. Our experience with the complex atmospheres of the known hot-Jupiters has demonstrated that insights are best gained through the combination of Spitzer observations and atmospheric modeling . However, no models have investigated the atmospheres of Neptune-class exoplanets, which may well be super metal-enriched, and span a wider range in stellar insolation and atmospheric composition than we have previously encountered. GJ 436b the coldest transiting planet, is in entirely new irradiation and mass regimes and is also the target of a barrage of planned Spitzer observations. Here we propose a new generation of atmospheric modeling to understand Spitzer observations of this new planet and others like it.

  11. MODIS Atmospheric Data Handler

    NASA Technical Reports Server (NTRS)

    Anantharaj, Valentine; Fitzpatrick, Patrick

    2008-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) Atmosphere Data Handler software converts the HDF data to ASCII format, and outputs: (1) atmospheric profiles of temperature and dew point and (2) total precipitable water. Quality-control data are also considered in the export procedure.

  12. GSFC Venus atmosphere simulator

    NASA Technical Reports Server (NTRS)

    Cridlin, M. S.; Munford, J. A.

    1974-01-01

    The design and preliminary testing of a Venus Atmosphere Simulation System are described. The system was designed for testing a quadrupole mass spectrometer proposed for the Pioneer-Venus Experiment. The system is capable of providing programmed temperature cycles up to 550 C, and manually controlled pressure up to 100 atmospheres.

  13. Atmospheric Forum Release

    Atmospheric Science Data Center

    2016-02-24

    ... ASDC is pleased to announce the release of the Atmospheric Science User Forum. The purpose of this forum is to improve user service, quality, and efficiency of NASA atmospheric science data by providing a quick and easy way to facilitate scientific ...

  14. Atmospheric Fluorescence Yield

    NASA Technical Reports Server (NTRS)

    Adams, James H., Jr.; Christl, M. J.; Fountain, W. F.; Gregory, J. C.; Martens, K.; Sokolsky, P.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Several existing and planned experiments estimate the energies of ultra-high energy cosmic rays from air showers using the atmospheric fluorescence from these showers. Accurate knowledge of the conversion from atmospheric fluorescence to energy loss by ionizing particles in the atmosphere is key to this technique. In this paper we discuss a small balloon-borne instrument to make the first in situ measurements versus altitude of the atmospheric fluorescence yield. The instrument can also be used in the lab to investigate the dependence of the fluorescence yield in air on temperature, pressure and the concentrations of other gases that present in the atmosphere. The results can be used to explore environmental effects on and improve the accuracy of cosmic ray energy measurements for existing ground-based experiments and future space-based experiments.

  15. Titan's Lower Atmosphere

    NASA Astrophysics Data System (ADS)

    Griffith, Caitlin Ann

    2007-09-01

    Saturn's largest moon, Titan, sports an atmosphere 10 times thicker than Earth's. Like Earth, the moon's atmosphere is N2 based and possesses a rich organic chemistry. In addition, similar to the terrestrial hydrological cycle, Titan has a methane cycle, with methane clouds, rain and seas. Presently, there is a revolution in our understanding of the moon, as data flows in and is analyzed from the NASA and ESA Cassini-Huygens mission. For example, seas were detected only this year. Here I will discuss the evolution of our understanding of Titan's atmosphere, its composition, chemistry, dynamics and origin. Current open questions will also be presented. Studies of Titan's atmosphere began and evolved to the present state in less time than that of a single scientist's career. This short interlude of activity demonstrates the rigors of the scientific method, and raises enticing questions about the workings and evolution of an atmosphere.

  16. The atmosphere below. (Videotape)

    SciTech Connect

    1992-12-31

    In this educational `Liftoff to Learning` video series, astronauts from the STS-45 Space Shuttle Mission (Kathy Sullivan, Byron Lichtenberg, Brian Duffy, Mike Foale, David Leestma, Charlie Bolden, and Dirk Frimont) explain and discuss the Earths atmosphere, its needs, the changes occurring within it, the importance of ozone, and some of the reasons behind the ozone depletion in the Earths atmosphere. The questions of: (1) what is ozone; (2) what has happened to the ozone layer in the atmosphere; and (3) what exactly does ozone do in the atmosphere, are answered. Different chemicals and their reactions with ozone are discussed. Computer animation and graphics show how these chemical reactions affect the atmosphere and how the ozone hole looks and develops at the south pole during its winter season appearance.

  17. Atmospheric distribution model

    NASA Astrophysics Data System (ADS)

    Zhang, Han-Wei; Li, Bin-Hua; Yang, Lei; Tie, Qiong-Xian; Mao, Wei

    2005-12-01

    Atmospheric vertical distributions and high altitude surveying techniques are described briefly. The reason why the atmospheric spherically symmetric distribution models are only adopted at present is analyzed. It is demonstrated that astronomical refraction measured models varied with change in observing stations and observation directions already have characteristics of non-spherically symmetric distribution of the real atmosphere over the observing stations so that there is no need to find or build atmospheric distribution models varied with change in topography and seasons. With the measured models, influences of ill selection of atmospheric distribution models can be avoided. All these from one side will ensure success in improving accuracies of the astronomical refraction correction and the radio wave refraction correction and the radio wave refraction delay correction.

  18. Update on atmospheric neutrinos

    SciTech Connect

    Gonzalez-Garcia, M.C.; Nunokawa, H.; Peres, O.L.; Valle, J.W.; Gonzalez-Garcia, M.C.; Stanev, T.

    1998-08-01

    We discuss the impact of recent experimental results on the determination of atmospheric neutrino oscillation parameters. We use all published results on atmospheric neutrinos, including the preliminary large statistics data of Super-Kamiokande. We reanalyze the data in terms of both {nu}{sub {mu}}{r_arrow}{nu}{sub {tau}} and {nu}{sub {mu}}{r_arrow}{nu}{sub e} channels using new improved calculations of the atmospheric neutrino flux. We compare the sensitivity attained in atmospheric neutrino experiments with those of accelerator and reactor neutrino oscillation searches, including the recent CHOOZ experiment. We briefly comment on the implications of atmospheric neutrino data in relation to future searches for neutrino oscillations with long baselines, such as the K2K, MINOS, ICARUS, and NOE experiments. {copyright} {ital 1998} {ital The American Physical Society}

  19. Geochemical cycles of atmospheric gases

    NASA Technical Reports Server (NTRS)

    Walker, J. C. G.; Drever, J. I.

    1988-01-01

    The processes that control the atmosphere and atmospheric changes are reviewed. The geochemical cycles of water vapor, nitrogen, carbon dioxide, oxygen, and minor atmospheric constituents are examined. Changes in atmospheric chemistry with time are discussed using evidence from the rock record and analysis of the present atmosphere. The role of biological evolution in the history of the atmosphere and projected changes in the future atmosphere are considered.

  20. Geospatial Predictive Modelling for Climate Mapping of Selected Severe Weather Phenomena Over Poland: A Methodological Approach

    NASA Astrophysics Data System (ADS)

    Walawender, Ewelina; Walawender, Jakub P.; Ustrnul, Zbigniew

    2016-02-01

    The main purpose of the study is to introduce methods for mapping the spatial distribution of the occurrence of selected atmospheric phenomena (thunderstorms, fog, glaze and rime) over Poland from 1966 to 2010 (45 years). Limited in situ observations as well the discontinuous and location-dependent nature of these phenomena make traditional interpolation inappropriate. Spatially continuous maps were created with the use of geospatial predictive modelling techniques. For each given phenomenon, an algorithm identifying its favourable meteorological and environmental conditions was created on the basis of observations recorded at 61 weather stations in Poland. Annual frequency maps presenting the probability of a day with a thunderstorm, fog, glaze or rime were created with the use of a modelled, gridded dataset by implementing predefined algorithms. Relevant explanatory variables were derived from NCEP/NCAR reanalysis and downscaled with the use of a Regional Climate Model. The resulting maps of favourable meteorological conditions were found to be valuable and representative on the country scale but at different correlation (r) strength against in situ data (from r = 0.84 for thunderstorms to r = 0.15 for fog). A weak correlation between gridded estimates of fog occurrence and observations data indicated the very local nature of this phenomenon. For this reason, additional environmental predictors of fog occurrence were also examined. Topographic parameters derived from the SRTM elevation model and reclassified CORINE Land Cover data were used as the external, explanatory variables for the multiple linear regression kriging used to obtain the final map. The regression model explained 89 % of annual frequency of fog variability in the study area. Regression residuals were interpolated via simple kriging.

  1. Origin and evolution of planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Lewis, John S.

    1992-01-01

    This report concerns several research tasks related to the origin and evolution of planetary atmospheres and the large-scale distribution of volatile elements in the Solar System. These tasks and their present status are as follows: (1) we have conducted an analysis of the volatility and condensation behavior of compounds of iron, aluminum, and phosphorus in the atmosphere of Venus in response to publish interpretations of the Soviet Venera probe XRF experiment data, to investigate the chemistry of volcanic gases, injection of volatiles by cometary and asteroidal impactors, and reactions in the troposphere; (2) we have completed and are now writing up our research on condensation-accretion modeling of the terrestrial planets; (3) we have laid the groundwork for a detailed study of the effects of water transport in the solar nebula on the bulk composition, oxidation state, and volatile content of preplanetary solids; (4) we have completed an extensive laboratory study of cryovolcanic materials in the outer solar system; (5) we have begun to study the impact erosion and shock alteration of the atmosphere of Mars resulting from cometary and asteroidal bombardment; and (6) we have developed a new Monte Carlo model of the cometary and asteroidal bombardment flux on the terrestrial planets, including all relevant chemical and physical processes associated with atmospheric entry and impact, to assess both the hazards posed by this bombardment to life on Earth and the degree of cross-correlation between the various phenomena (NO(x) production, explosive yield, crater production, iridium signature, etc.) that characterize this bombardment. The purpose of these investigations has been to contribute to the developing understanding of both the dynamics of long-term planetary atmosphere evolution and the short-term stability of planetary surface environments.

  2. Modelling transport phenomena in a multi-physics context

    SciTech Connect

    Marra, Francesco

    2015-01-22

    Innovative heating research on cooking, pasteurization/sterilization, defrosting, thawing and drying, often focuses on areas which include the assessment of processing time, evaluation of heating uniformity, studying the impact on quality attributes of the final product as well as considering the energy efficiency of these heating processes. During the last twenty years, so-called electro-heating-processes (radio-frequency - RF, microwaves - MW and ohmic - OH) gained a wide interest in industrial food processing and many applications using the above mentioned technologies have been developed with the aim of reducing processing time, improving process efficiency and, in many cases, the heating uniformity. In the area of innovative heating, electro-heating accounts for a considerable portion of both the scientific literature and commercial applications, which can be subdivided into either direct electro-heating (as in the case of OH heating) where electrical current is applied directly to the food or indirect electro-heating (e.g. MW and RF heating) where the electrical energy is firstly converted to electromagnetic radiation which subsequently generates heat within a product. New software packages, which make easier solution of PDEs based mathematical models, and new computers, capable of larger RAM and more efficient CPU performances, allowed an increasing interest about modelling transport phenomena in systems and processes - as the ones encountered in food processing - that can be complex in terms of geometry, composition, boundary conditions but also - as in the case of electro-heating assisted applications - in terms of interaction with other physical phenomena such as displacement of electric or magnetic field. This paper deals with the description of approaches used in modelling transport phenomena in a multi-physics context such as RF, MW and OH assisted heating.

  3. Switching Phenomena in a System with No Switches

    NASA Astrophysics Data System (ADS)

    Preis, Tobias; Stanley, H. Eugene

    2010-02-01

    It is widely believed that switching phenomena require switches, but this is actually not true. For an intriguing variety of switching phenomena in nature, the underlying complex system abruptly changes from one state to another in a highly discontinuous fashion. For example, financial market fluctuations are characterized by many abrupt switchings creating increasing trends ("bubble formation") and decreasing trends ("financial collapse"). Such switching occurs on time scales ranging from macroscopic bubbles persisting for hundreds of days to microscopic bubbles persisting only for a few seconds. We analyze a database containing 13,991,275 German DAX Future transactions recorded with a time resolution of 10 msec. For comparison, a database providing 2,592,531 of all S&P500 daily closing prices is used. We ask whether these ubiquitous switching phenomena have quantifiable features independent of the time horizon studied. We find striking scale-free behavior of the volatility after each switching occurs. We interpret our findings as being consistent with time-dependent collective behavior of financial market participants. We test the possible universality of our result by performing a parallel analysis of fluctuations in transaction volume and time intervals between trades. We show that these financial market switching processes have properties similar to those of phase transitions. We suggest that the well-known catastrophic bubbles that occur on large time scalessuch as the most recent financial crisisare no outliers but single dramatic representatives caused by the switching between upward and downward trends on time scales varying over nine orders of magnitude from very large (?102 days) down to very small (?10 ms).

  4. Space Commercial Opportunities for Fluid Physics and Transport Phenomena Applications

    NASA Technical Reports Server (NTRS)

    Gavert, R.

    2000-01-01

    Microgravity research at NASA has been an undertaking that has included both science and commercial approaches since the late 80s and early 90s. The Fluid Physics and Transport Phenomena community has been developed, through NASA's science grants, into a valuable base of expertise in microgravity science. This was achieved through both ground and flight scientific research. Commercial microgravity research has been primarily promoted thorough NASA sponsored Centers for Space Commercialization which develop cost sharing partnerships with industry. As an example, the Center for Advanced Microgravity Materials Processing (CAMMP)at Northeastern University has been working with cost sharing industry partners in developing Zeolites and zeo-type materials as an efficient storage medium for hydrogen fuel. Greater commercial interest is emerging. The U.S. Congress has passed the Commercial Space Act of 1998 to encourage the development of a commercial space industry in the United States. The Act has provisions for the commercialization of the International Space Station (ISS). Increased efforts have been made by NASA to enable industrial ventures on-board the ISS. A Web site has been established at http://commercial/nasa/gov which includes two important special announcements. One is an open request for entrepreneurial offers related to the commercial development and use of the ISS. The second is a price structure and schedule for U.S. resources and accommodations. The purpose of the presentation is to make the Fluid Physics and Transport Phenomena community, which understands the importance of microgravity experimentation, aware of important aspects of ISS commercial development. It is a desire that this awareness will be translated into a recognition of Fluid Physics and Transport Phenomena application opportunities coordinated through the broad contacts of this community with industry.

  5. Modelling transport phenomena in a multi-physics context

    NASA Astrophysics Data System (ADS)

    Marra, Francesco

    2015-01-01

    Innovative heating research on cooking, pasteurization/sterilization, defrosting, thawing and drying, often focuses on areas which include the assessment of processing time, evaluation of heating uniformity, studying the impact on quality attributes of the final product as well as considering the energy efficiency of these heating processes. During the last twenty years, so-called electro-heating-processes (radio-frequency - RF, microwaves - MW and ohmic - OH) gained a wide interest in industrial food processing and many applications using the above mentioned technologies have been developed with the aim of reducing processing time, improving process efficiency and, in many cases, the heating uniformity. In the area of innovative heating, electro-heating accounts for a considerable portion of both the scientific literature and commercial applications, which can be subdivided into either direct electro-heating (as in the case of OH heating) where electrical current is applied directly to the food or indirect electro-heating (e.g. MW and RF heating) where the electrical energy is firstly converted to electromagnetic radiation which subsequently generates heat within a product. New software packages, which make easier solution of PDEs based mathematical models, and new computers, capable of larger RAM and more efficient CPU performances, allowed an increasing interest about modelling transport phenomena in systems and processes - as the ones encountered in food processing - that can be complex in terms of geometry, composition, boundary conditions but also - as in the case of electro-heating assisted applications - in terms of interaction with other physical phenomena such as displacement of electric or magnetic field. This paper deals with the description of approaches used in modelling transport phenomena in a multi-physics context such as RF, MW and OH assisted heating.

  6. Thermomagnetic phenomena in the mixed state of high temperature superconductors

    NASA Technical Reports Server (NTRS)

    Meilikhov, E. Z.

    1995-01-01

    Galvano- and thermomagnetic-phenomena in high temperature superconductors, based on kinetic coefficients, are discussed, along with a connection between the electric field and the heat flow in superconductor mixed state. The relationship that determines the transport coefficients of high temperature superconductors in the mixed state based on Seebeck and Nernst effects is developed. It is shown that this relationship is true for a whole transition region of the resistive mixed state of a superconductor. Peltier, Ettingshausen and Righi-Leduc effects associated with heat conductivity as related to high temperature superconductors are also addressed.

  7. Strong-randomness phenomena in quantum Ashkin-Teller models

    NASA Astrophysics Data System (ADS)

    Barghathi, Hatem; Hrahsheh, Fawaz; Hoyos, Jos A.; Narayanan, Rajesh; Vojta, Thomas

    2015-10-01

    The N-color quantum Ashkin-Teller spin chain is a prototypical model for the study of strong-randomness phenomena at first-order and continuous quantum phase transitions. In this paper, we first review the existing strong-disorder renormalization group approaches to the random quantum Ashkin-Teller chain in the weak-coupling as well as the strong-coupling regimes. We then introduce a novel general variable transformation that unifies the treatment of the strong-coupling regime. This allows us to determine the phase diagram for all color numbers N, and the critical behavior for all N\

  8. Analysis of interaction phenomena between liquid jets and materials [preprint

    SciTech Connect

    Kang, S-W.; Reitter, T.; Carlson, G.

    1995-04-01

    The interaction phenomena of high-velocity liquid jets impinging on a material surface have been investigated theoretically and experimentally to understand the physics of material removal by jet-machining processes. Experiments were performed to delineate conditions under which liquid jet impacts will cause mass removal and to determine optimum jet-cutting conditions. Theoretical analyses have also been carried out to study the effects of multiple jet-droplet impacts on a target surface as a material deformation mechanism. The calculated target response and spallation behavior following droplet impacts and their physical implications are also discussed.

  9. Interference phenomena at backscattering by ice crystals of irregular shape

    NASA Astrophysics Data System (ADS)

    Konoshonkin, Alexander V.; Kustova, Natalia V.; Borovoi, Anatoli G.

    2015-11-01

    It is shown that light backscattering by hexagonal ice crystals of cirrus clouds is formed by both diffraction and interference phenomena. Diffraction determines the angular width of the backscattering peak and interference produces the interference rings inside the peak. By use of a simplest model for distortion of the pristine hexagonal shape, we show that the shape distortion leads to both oscillations of the scattering (Mueller) matrix within the backscattering peak and to a strong increase of the depolarization, color, and lidar ratios needed for interpretation of lidar signals.

  10. Interference phenomena at backscattering by ice crystals of cirrus clouds.

    PubMed

    Borovoi, Anatoli; Kustova, Natalia; Konoshonkin, Alexander

    2015-09-21

    It is shown that light backscattering by hexagonal ice crystals of cirrus clouds is formed within the physical-optics approximation by both diffraction and interference phenomena. Diffraction determines the angular width of the backscattering peak and interference produces the interference rings inside the peak. By use of a simple model for distortion of the pristine hexagonal shape, we show that the shape distortion leads to both oscillations of the scattering (Mueller) matrix within the backscattering peak and to a strong increase of the depolarization, color, and lidar ratios needed for interpretation of lidar signals. PMID:26406659

  11. Mutual phenomena involving J5 Amalthea in 2002-2003

    NASA Astrophysics Data System (ADS)

    Vachier, F.; Arlot, J. E.; Thuillot, W.

    2002-10-01

    Every six years mutual eclipses and occultations occur among the Jovian system of satellites. Very accurate astrometric measurements and several physical characteristics of the surfaces can be infered from their observation. This paper is provide predictions of this type of events involving the fifth satellite J5 Amalthea, spanning from November 2002 to June 2003 and to urge astronomers to observe them. Only the predictions of the eclipses of Amalthea by Io are presented, when the distance between Amalthea-Io and Amalthea-Jutpiter is large enough for photometric purposes. A full list of phenomena is available on the server http://www.imcce.fr/Phemu03/phemu03_eng.html

  12. Transport phenomena of aluminium oxide in metal halide lamps

    NASA Astrophysics Data System (ADS)

    Fischer, S.; Niemann, U.; Markus, T.

    2008-07-01

    A better understanding of the transport phenomena observed in metal halide lamps can be achieved using computer-based model calculations. The chemical transport of aluminium oxide in advanced high-pressure discharge vessels was calculated as a function of temperature and composition of the salt mixture relevant to the lamp. Below 1773 K chemical transport is the prevailing process; above this temperature the vaporization and condensation of the envelope materialaluminium oxidebecome more important. The results of the calculations show that the amount of transported alumina increases linearly with the number of iteration cycles and exponentially with the temperature gradient.

  13. Visualization of In-Flight Flow Phenomena Using Infrared Thermography

    NASA Technical Reports Server (NTRS)

    Banks, D. W.; vanDam, C. P.; Shiu, H. J.; Miller, G. M.

    2000-01-01

    Infrared thermography was used to obtain data on the state of the boundary layer of a natural laminar flow airfoil in supersonic flight. In addition to the laminar-to-turbulent transition boundary, the infrared camera was able to detect shock waves and present a time dependent view of the flow field. A time dependent heat transfer code was developed to predict temperature distributions on the test subject and any necessary surface treatment. A commercially available infrared camera was adapted for airborne use in this application. Readily available infrared technology has the capability to provide detailed visualization of various flow phenomena in subsonic to hypersonic flight regimes.

  14. Correlation between solar neutrino flux and other solar phenomena

    NASA Technical Reports Server (NTRS)

    Lal, S.; Subramanian, A.

    1985-01-01

    A study was made of the solar neutrino data with a tank of CC14 located 4800 mwe underground for the period 1970 to 83. These observations are on the production rates of Ar37 atoms via the reaction upsilon sub e + Cl37 yields Ar37 plus e(-) in the tank caused presumably by a flux of neutrinos from the Sun. The idea of possible time variations in the data shown is discussed and an attempt is made to correlate the variations to two other phenomena of solar origin-the sunspot number and the geomagnetic Ap index.

  15. Management of spasticity, pain, and paroxysmal phenomena in multiple sclerosis.

    PubMed

    Schapiro, R T

    2001-05-01

    Multiple sclerosis (MS) is a disease with tremendous variability and innumerable symptoms. Among the more common symptoms is spasticity. Despite a lack of full knowledge of the physiology causing this phenomenon, successful treatments have been developed. Many of these have had a recent introduction. Pain and paroxysmal phenomena are surprisingly common in MS, but have not had the recognition their frequency deserves. It is not unusual to hear that they are rare in MS, but surprisingly they are all too common. Their management is changing as newer treatments are developed. PMID:11898533

  16. An investigation of the damping phenomena in wire rope isolators

    NASA Technical Reports Server (NTRS)

    Cutchins, M. A.; Cochran, J. E., Jr.; Guest, S.; Fitz-Coy, N. G.; Tinker, M. L.

    1987-01-01

    Early investigations into analytically modeling the dynamics of wire rope vibration isolators are described. Results from both very simple and very complex models are shown. The dynamic model which has the best agreement to date with simple one-dimensional experiments is one which includes a Coulomb friction force which varies with frequency. There are many yet unexplained phenomena, however. The fundamentals which underly multistrand NASTRAN models are given, and some early results are shown. An application simulation is briefly described, as is ongoing research.

  17. Damping phenomena in a wire rope vibration isolation system

    NASA Technical Reports Server (NTRS)

    Tinker, Michael L.; Cutchins, Malcolm A.

    1990-01-01

    A study of the dynamic characteristics of a wire rope vibration isolation system constructed with helical isolators is presented. Emphasis is placed on the analytical modeling of damping mechanisms in the system. An experimental investigation is described in which the static stiffness curve, hysteresis curves, phase trajectories, and frequency response curves were obtained. A semi-empirical model having nonlinear stiffness, nth-power velocity damping, and variable Coulomb friction damping is developed and results are compared to experimental data. Conclusions about dynamic phenomena in the wire rope system are made based on the experimental and semi-empirical results.

  18. Damping phenomena in a wire rope vibration isolation system

    NASA Technical Reports Server (NTRS)

    Tinker, M. L.; Cutchins, M. A.

    1992-01-01

    A study is presented of the dynamic characteristics of a wire rope vibration isolation system constructed with helical isolators, with emphasis placed on the analytical modeling of damping mechanisms in the system. An experimental investigation is described in which the static stiffness curve, hysteresis curves, phase plane trajectories, and frequency response curves are obtained. A semiempirical model having nonlinear stiffness, nth-power velocity damping, and variable Coulomb friction damping is developed, and the results are compared to experimental data. Several observations and conclusions are made about the dynamic phenomena in a typical wire rope vibration isolation system based on the experimental and semiempirical results.

  19. Traditional and alert hypnotic phenomena: development through anteriorization.

    PubMed

    Wark, David M

    2015-01-01

    Modern research techniques show that hypnotic induction involves behavioral and cognitive inhibition as components of many hypnotic phenomena. One standard laboratory technique for measuring cognitive inhibition is the Go/NoGo procedure. The procedure moves the average, or centroid, of electroencephalography signals toward the frontal, or anterior, part of the brain. This process, called anteriorization, produces a shift in the emotional and cognitive signals from the anterior cingulate cortex. This has implications for both the scientific understanding and clinical use of hypnosis. PMID:25928678

  20. Investigation of surface tension phenomena using the KC-135 aircraft

    NASA Technical Reports Server (NTRS)

    Alter, W. S.

    1982-01-01

    The microgravity environment of the KC-135 aircraft was utilized in three experiments designed to determine the following: (1) the feasibility of measuring critical wetting temperatures; (2) the effectiveness of surface tension as a means of keeping the cushioning heat transfer liquid in the furnace during ampoule translation; and (3) whether a non-wetting fluid would separate from the ampoule wall under low gravity conditions. This trio of investigations concerning surface phenomena demonstrates the effectiveness of the KC-135 as a microgravity research environment for small-scale, hand-held experiments.

  1. Applications for nuclear phenomena generated by ultra-intense lasers.

    PubMed

    Ledingham, K W D; McKenna, P; Singhal, R P

    2003-05-16

    The amplification of laser light to generate powers large enough to affect the nucleus has been the desire of scientists since the invention of the laser 40 years ago. Many lasers, including tabletop varieties, now have pulse powers greater than the electrical power generated by all the world's power plants combined. When this power is focused to dimensions of a few microns, laser-driven nuclear phenomena can occur. Here we review the developments in this research field and describe the potential of laser produced proton, neutron, and heavy ion beams, together with isotope and isomer production. PMID:12750510

  2. Critical phenomena of dynamical delocalization in a quantum Anderson map

    NASA Astrophysics Data System (ADS)

    Yamada, Hiroaki S.; Matsui, Fumihiro; Ikeda, Kensuke S.

    2015-12-01

    Using a quantum map version of the one-dimensional Anderson model, the localization-delocalization transition of quantum diffusion induced by coherent dynamical perturbation is investigated in comparison with the quantum standard map. Existence of critical phenomena, which depends on the number of frequency component M , is demonstrated. Diffusion exponents agree with theoretical prediction for the transition, but the critical exponent of the localization length deviates from it with increase in the M . The critical power ɛc of the normalized perturbation at the transition point remarkably decreases as ɛc˜(M-1 ) -1 .

  3. Damping phenomena in a wire rope vibration isolation system

    NASA Astrophysics Data System (ADS)

    Tinker, Michael L.; Cutchins, Malcolm A.

    A study of the dynamic characteristics of a wire rope vibration isolation system constructed with helical isolators is presented. Emphasis is placed on the analytical modeling of damping mechanisms in the system. An experimental investigation is described in which the static stiffness curve, hysteresis curves, phase trajectories, and frequency response curves were obtained. A semi-empirical model having nonlinear stiffness, nth-power velocity damping, and variable Coulomb friction damping is developed and results are compared to experimental data. Conclusions about dynamic phenomena in the wire rope system are made based on the experimental and semi-empirical results.

  4. Damping phenomena in a wire rope vibration isolation system

    NASA Astrophysics Data System (ADS)

    Tinker, M. L.; Cutchins, M. A.

    1992-08-01

    A study is presented of the dynamic characteristics of a wire rope vibration isolation system constructed with helical isolators, with emphasis placed on the analytical modeling of damping mechanisms in the system. An experimental investigation is described in which the static stiffness curve, hysteresis curves, phase plane trajectories, and frequency response curves are obtained. A semiempirical model having nonlinear stiffness, nth-power velocity damping, and variable Coulomb friction damping is developed, and the results are compared to experimental data. Several observations and conclusions are made about the dynamic phenomena in a typical wire rope vibration isolation system based on the experimental and semiempirical results.

  5. Analyzing simple pendulum phenomena with a smartphone acceleration sensor

    NASA Astrophysics Data System (ADS)

    Vogt, Patrik; Kuhn, Jochen

    2012-10-01

    This paper describes a further experiment using the acceleration sensor of a smartphone. For a previous column on this topic, including the description of the operation and use of the acceleration sensor, see Ref. 1. In this contribution we focus on analyzing simple pendulum phenomena. A smartphone is used as a pendulum bob, and SPARKvue2 software is used in conjunction with an iPhone or an iPod touch, or the Accelogger3 app for an Android device. As described in Ref. 1, the values measured by the smartphone are subsequently exported to a spreadsheet application (e.g., MS Excel) for analysis.

  6. A review of experimental investigations on thermal phenomena in nanofluids

    PubMed Central

    2011-01-01

    Nanoparticle suspensions (nanofluids) have been recommended as a promising option for various engineering applications, due to the observed enhancement of thermophysical properties and improvement in the effectiveness of thermal phenomena. A number of investigations have been reported in the recent past, in order to quantify the thermo-fluidic behavior of nanofluids. This review is focused on examining and comparing the measurements of convective heat transfer and phase change in nanofluids, with an emphasis on the experimental techniques employed to measure the effective thermal conductivity, as well as to characterize the thermal performance of systems involving nanofluids. PMID:21711918

  7. Generality of hydrophobic phenomena for aqueous solutions of amphiphiles

    NASA Astrophysics Data System (ADS)

    Zemnkov, Katerina; Troncoso, Jacobo; Cerdeiria, Claudio A.; Roman, Luis

    2015-11-01

    With the temperature and composition dependence of the isobaric heat capacity as our experimental probe, previously reported anomalous behaviors for tert-butanol and 2-butoxyethanol in water are shown to belong to a general scheme for aqueous solutions of amphiphiles. As opposed to a pretransitional scenario, our results point towards aggregation of the hydrophobic moieties of solute molecules as the origin of the phenomenology. The locus in the mole fraction-temperature plane that maps anomalies for 1-pentylamine solutions extends to quite small concentrations and 330 K, thereby raising questions on the roles of hydration and aggregation in phenomena involving so-called 'molecular hydrophobic interfaces'.

  8. Comparative analyses of observations of lunar transient phenomena.

    NASA Technical Reports Server (NTRS)

    Cameron, W. S.

    1972-01-01

    From the author's collection of more than 900 reports of lunar transient phenomena (LTP) covering the period 1540-1970, 771 positive plus 112 negative observations (several times more than any previously published analyses) with sufficient ancillary data were analyzed for five hypotheses of causes. Treated as two groups they were divided into four categories (gaseous, reddish, bluish, and brightenings) and were analyzed separately and combined with respect to the hypotheses. The five hypotheses involved effects of tides, sunrise, low-angle illumination, earth's magnetic tail, and solar particles.

  9. Measurement of Flow Phenomena in a VHTR Lower Plenum Model

    SciTech Connect

    Hugh M. McIlroy Jr.; Donald M. McEligot; Robert J. Pink

    2007-06-01

    Mean velocity and turbulence data that measure turbulent flow phenomena in an approximately 1:7 scale model of a region of the lower plenum of a typical prismatic gas-cooled reactor are presented as a follow-up to summaries presented at the 2006 Annual Meeting and the 2006 Winter Meeting. The experiments were designed to develop benchmark databases to support the first Standard Problem endorsed by the Generation IV International Forum to validate the heat transfer and fluid flow software that will be used to study the behavior of the VHTR system.

  10. An assessment of transient hydraulics phenomena and its characterization

    NASA Technical Reports Server (NTRS)

    Mortimer, R. W.

    1974-01-01

    A systematic search of the open literature was performed with the purpose of identifying the causes, effects, and characterization (modelling and solution techniques) of transient hydraulics phenomena. The governing partial differential equations are presented which were found to be used most often in the literature. Detail survey sheets are shown which contain the type of hydraulics problem, the cause, the modelling, the solution technique utilized, and experimental verification used for each paper. References and source documents are listed and a discussion of the purpose and accomplishments of the study is presented.

  11. Complex Phenomena in Orchestras - Metaphors for Leadership and Enterprise

    NASA Astrophysics Data System (ADS)

    Beautement, Patrick; Brönner, Christine

    This paper recognises that comparisons have been made between the role of the conductor of an orchestra and leaders of enterprises, but that little note has been taken of how the complex dynamics of orchestras can provide metaphors for transformational and / or evolutionary behaviour in complex enterprises. The paper intends to identify some of the dynamic musical patterns and phenomena that exist in orchestras and show how these can provide insights for other domains where similar complex federated structures emerge ’on-the-fly’ by providing and using a complexity-inspired framework.

  12. Lattice analysis for the energy scale of QCD phenomena.

    PubMed

    Yamamoto, Arata; Suganuma, Hideo

    2008-12-12

    We formulate a new framework in lattice QCD to study the relevant energy scale of QCD phenomena. By considering the Fourier transformation of link variable, we can investigate the intrinsic energy scale of a physical quantity nonperturbatively. This framework is broadly available for all lattice QCD calculations. We apply this framework for the quark-antiquark potential and meson masses in quenched lattice QCD. The gluonic energy scale relevant for the confinement is found to be less than 1 GeV in the Landau or Coulomb gauge. PMID:19113611

  13. Theory of quantum coherence phenomena in semiconductor quantum dots.

    SciTech Connect

    Chow, Weng Wah; Phillips, Mark Christopher; Schneider, Hans Christian

    2003-06-01

    This paper explores quantum-coherence phenomena in a semiconductor quantum-dot structure. The calculations predict the occurrence of inversionless gain, electromagnetically induced transparency, and refractive-index enhancement in the transient regime for dephasing rates typical under room temperature and high excitation conditions. They also indicate deviations from atomic systems because of strong many-body effects. Specifically, Coulomb interaction involving states of the quantum dots and the continuum belonging to the surrounding quantum well leads to collision-induced population redistribution and many-body energy and field renormalizations that modify the magnitude, spectral shape, and time dependence of quantum-coherence effects.

  14. Reference Atmosphere for Mercury

    NASA Technical Reports Server (NTRS)

    Killen, Rosemary M.

    2002-01-01

    We propose that Ar-40 measured in the lunar atmosphere and that in Mercury's atmosphere is due to current diffusion into connected pore space within the crust. Higher temperatures at Mercury, along with more rapid loss from the atmosphere will lead to a smaller column abundance of argon at Mercury than at the Moon, given the same crustal abundance of potassium. Because the noble gas abundance in the Hermean atmosphere represents current effusion, it is a direct measure of the crustal potassium abundance. Ar-40 in the atmospheres of the planets is a measure of potassium abundance in the interiors, since Ar-40 is a product of radiogenic decay of K-40 by electron capture with the subsequent emission of a 1.46 eV gamma-ray. Although the Ar-40 in the Earth's atmosphere is expected to have accumulated since the late bombardment, Ar-40 in the atmospheres of Mercury and the Moon is eroded quickly by photoionization and electron impact ionization. Thus, the argon content in the exospheres of the Moon and Mercury is representative of current effusion rather than accumulation over the lifetime of the planet.

  15. Simulation of atmospheric temperature effects on cosmic ray muon flux

    NASA Astrophysics Data System (ADS)

    Tognini, Stefano Castro; Gomes, Ricardo Avelino

    2015-05-01

    The collision between a cosmic ray and an atmosphere nucleus produces a set of secondary particles, which will decay or interact with other atmosphere elements. This set of events produced a primary particle is known as an extensive air shower (EAS) and is composed by a muonic, a hadronic and an electromagnetic component. The muonic flux, produced mainly by pions and kaons decays, has a dependency with the atmosphere's effective temperature: an increase in the effective temperature results in a lower density profile, which decreases the probability of pions and kaons to interact with the atmosphere and, consequently, resulting in a major number of meson decays. Such correlation between the muon flux and the atmosphere's effective temperature was measured by a set of experiments, such as AMANDA, Borexino, MACRO and MINOS. This phenomena can be investigated by simulating the final muon flux produced by two different parameterizations of the isothermal atmospheric model in CORSIKA, where each parameterization is described by a depth function which can be related to the muon flux in the same way that the muon flux is related to the temperature. This research checks the agreement among different high energy hadronic interactions models and the physical expected behavior of the atmosphere temperature effect by analyzing a set of variables, such as the height of the primary interaction and the difference in the muon flux.

  16. Calibrating Atmospheric Transmission

    NASA Astrophysics Data System (ADS)

    Zimmer, Peter C.; McGraw, J. T.; Vorobiev, D. M.; Zirzow, D. C.; Karle, J. C.; Lykke, K. R.; Woodward, J. T.; Cramer, C. E.

    2012-01-01

    Earth's atmosphere is a wavelength-, directionally- and time-dependent turbid refractive element for every ground-based telescope. Changes in atmospheric transmission are the most significant systematic error limiting photometric measurement precision and accuracy. While considerable resources have been devoted to correcting the effects of the atmosphere on angular resolution, the effects on precision photometry have largely been ignored. To correct photometric measurements for the transmission of the atmosphere requires direct measurements of the wavelength-dependent transmission in the same direction and at the same time that the supported photometric telescope is acquiring its data. We describe the multi-wavelength lidar, the Facility Lidar for Astronomical Measurement of Extinction (FLAME) that observes the stable stratosphere, and a spectrophotometer (the Astronomical Extinction Spectrophotometer - AESoP) that creates and maintains NIST absolute standard stars, the combination of which enables fundamentally statistically limited photometric precision of both the stellar spectra and atmospheric transmission. The throughput of both FLAME and AESoP are calibrated to NIST radiometric standards. This inexpensive and replicable instrument suite provides the lidar-determined monochromatic transmission of Earth's atmosphere at visible and near-infrared wavelengths to 0.25% per airmass and the wavelength-dependent transparency to less than 1% uncertainty per nanometer per minute of time. These atmospheric data are merged to create a metadata stream that allows throughput corrections from data acquired at the time of the scientific observations to be applied to broadband and spectrophotometric scientific data. This new technique replaces the classical use of nightly mean atmospheric extinction coefficients, which invoke a stationary and plane-parallel atmosphere and ultimately limit ground-based all-sky photometry to 1% - 2% precision. This research is supported by NIST Award 60NANB9D9121 and NSF Grant AST-1009878.

  17. Atmospheric ionisation in Snowdonia

    NASA Astrophysics Data System (ADS)

    Aplin, K. L.; Williams, J. H.

    2011-06-01

    Atmospheric ionisation from natural radioactivity and cosmic rays has been measured at several sites in Snowdonia from 2005-present. The motivation for this project was a combination of public engagement with science, and research into the effects of ionisation on climate. A four-component atmospheric radiometer instrument is co-located with the ionisation detectors and the data is remotely logged and displayed on the Web. Atmospheric ionisation from natural radioactivity varies with local geology, and the cosmic ray ionisation component is modulated by solar activity and altitude. Variations due to all these effects have been identified and are described.

  18. Evolution of Atmospheres

    SciTech Connect

    Hanson, B.

    1993-02-12

    An atmosphere is the dynamic gaseous boundary layer between a planet and space. Many complex interactions affect the composition and time evolution of an atmosphere and control the environment - or climate - at a planet's surface. These include both reactions within the atmosphere as well as exchange of energy, gases, and dust with the planet below and the solar system above; for Earth today, interactions with the biosphere and oceans are paramount. In view of the large changes in inputs of energy and gases that have occurred since planets began to form and the complexity of the chemistry, it is not surprising that planetary climates have changed greatly and are continuing to change.

  19. Middle atmosphere tides

    NASA Technical Reports Server (NTRS)

    Forbes, J. M.

    1985-01-01

    The recent direction of theoretical and observational research in middle atmosphere tides is reviewed. The diurnal tide has received considerable emphasis, including observations of evanescent components at high latitudes, numerical simulations of nonmigrating propagating components due to longitudinally varying water vapor insolation absorption in the troposphere, and implications and origins of unsteadiness in tidal oscillations over periods of days. Recent analyses of Nimbus 7 LIMS temperatures and partial reflection drift measurements of neutral winds in the tropical mesosphere have also emphasized the diurnal propagating tide. A description of the Atmospheric Tides Middle Atmosphere Program (ATMAP) and an overview of ATMAP campaign results are also presented.

  20. Triton's Distorted Atmosphere

    NASA Technical Reports Server (NTRS)

    Elliot, J. L.; Stansberry, J. A.; Olkin, C. B.; Agner, M. A.; Davies, M. E.

    1998-01-01

    A stellar-occultation light curve for Triton shows asymmetry that can be understood if Triton's middle atmosphere is distorted from spherical symmetry. Although a globally oblate model can explain the data, the inferred atmospheric flattening is so large that it could be caused only by an unrealistic internal mass distribution or highly supersonic zonal winds. Cyclostrophic winds confined to a jet near Triton's northern or southern limbs (or both) could also be responsible for the details of the light curve, but such winds are required to be slightly supersonic. Hazes and clouds in the atmosphere are unlikely to have caused the asymmetry in the light curve.

  1. Atmospheric refraction: a history

    NASA Astrophysics Data System (ADS)

    Lehn, Waldemar H.; van der Werf, Siebren

    2005-09-01

    We trace the history of atmospheric refraction from the ancient Greeks up to the time of Kepler. The concept that the atmosphere could refract light entered Western science in the second century B.C. Ptolemy, 300 years later, produced the first clearly defined atmospheric model, containing air of uniform density up to a sharp upper transition to the ether, at which the refraction occurred. Alhazen and Witelo transmitted his knowledge to medieval Europe. The first accurate measurements were made by Tycho Brahe in the 16th century. Finally, Kepler, who was aware of unusually strong refractions, used the Ptolemaic model to explain the first documented and recognized mirage (the Novaya Zemlya effect).

  2. Ensemble Atmospheric Dispersion Modeling

    SciTech Connect

    Addis, R.P.

    2002-06-24

    Prognostic atmospheric dispersion models are used to generate consequence assessments, which assist decision-makers in the event of a release from a nuclear facility. Differences in the forecast wind fields generated by various meteorological agencies, differences in the transport and diffusion models, as well as differences in the way these models treat the release source term, result in differences in the resulting plumes. Even dispersion models using the same wind fields may produce substantially different plumes. This talk will address how ensemble techniques may be used to enable atmospheric modelers to provide decision-makers with a more realistic understanding of how both the atmosphere and the models behave.

  3. Atmospheric Mercury Deposition Monitoring National Atmospheric Deposition Program (NADP)

    EPA Science Inventory

    The National Atmospheric Deposition Program (NADP) developed and operates a collaborative network of atmospheric mercury monitoring sites based in North America the Atmospheric Mercury Network (AMNet). The justification for the network was growing interest and demand from many ...

  4. The Transfer Function Model (TFM) as a Tool for Simulating Gravity Wave Phenomena in the Mesosphere

    NASA Astrophysics Data System (ADS)

    Porter, H.; Mayr, H.; Moore, J.; Wilson, S.; Armaly, A.

    2008-12-01

    The Transfer Function Model (TFM) is semi-analytical and linear, and it is designed to describe the acoustic gravity waves (GW) propagating over the globe and from the ground to 600 km under the influence of vertical temperature variations. Wave interactions with the flow are not accounted for. With an expansion in terms of frequency-dependent spherical harmonics, the time consuming vertical integration of the conservation equations is reduced to computing the transfer function (TF). (The applied lower and upper boundary conditions assure that spurious wave reflections will not occur.) The TF describes the dynamical properties of the medium divorced from the complexities of the temporal and horizontal variations of the excitation source. Given the TF, the atmospheric response to a chosen source is then obtained in short order to simulate the GW propagating through the atmosphere over the globe. In the past, this model has been applied to study auroral processes, which produce distinct wave phenomena such as: (1) standing lamb modes that propagate horizontally in the viscous medium of the thermosphere, (2) waves generated in the auroral oval that experience geometric amplification propagating to the pole where constructive interference generates secondary waves that propagate equatorward, (3) ducted modes propagating through the middle atmosphere that leak back into the thermosphere, and (4) GWs reflected from the Earth's surface that reach the thermosphere in a narrow propagation cone. Well-defined spectral features characterize these wave modes in the TF to provide analytical understanding. We propose the TFM as a tool for simulating GW in the mesosphere and in particular the features observed in Polar Mesospheric Clouds (PMC). With present-day computers, it takes less than one hour to compute the TF, so that there is virtually no practical limitation on the source configurations that can be applied and tested in the lower atmosphere. And there is no limitation on the temporal and spatial resolutions the model simulations can provide. We shall discuss the concept and organization of the TFM and present samples of GW simulations that illustrate the capabilities of the model and its user interface. We shall discuss in particular the waves that leak into the mesopause from the thermosphere above and propagate into the region from tropospheric weather systems below.

  5. Investigation of transient earth resources phenomena: Continuation study

    NASA Technical Reports Server (NTRS)

    Goldman, G. C.

    1974-01-01

    Calculated sensitivity requirements for an earth resource satellite in a geostationary orbit are reported. Radiance levels at the satellite sensor were computed for twenty top-priority Synchronous Earth Observatory Satellite (SEOS) applications. The observation requirements were reviewed and re-evaluated in terms of spectral band definition, spectral signatures of targets and backgrounds, observation time, and site location. With these data and an atmospheric attenuation and scattering model, the total radiances observed by the SEOS sensor were calculated as were the individual components contributed by the target, target variations, and the atmosphere.

  6. Simple Experiments to Help Students Understand Magnetic Phenomena

    NASA Astrophysics Data System (ADS)

    Browne, Kerry; Jackson, David P.

    2007-10-01

    The principles of magnetism are a common topic in most introductory physics courses, yet curricular materials exploring the behavior of permanent magnets and magnetic materials are surprisingly rare in the literature. We reviewed the literature to see how magnetism is typically covered in introductory textbooks and curricula. We found that while most texts contain a relatively complete description of magnetism and its relation to current-carrying wires, few devote much space to the development of a model that explains the magnetic phenomena students are most familiar with, e.g., the interaction between permanent magnets and ferromagnetic materials. We also found that while there are a wide variety of published articles exploring the various principles of magnetic induction, only a few of these explore the basic interactions between common magnets, ferromagnetic materials, and current-carrying wires.2,3 The activities described in this paper were designed to provide a structured series of simple experiments to help students develop a model of magnetism capable of explaining these phenomena.

  7. Surface electroluminescence phenomena correlated with trapping parameters of insulating polymers

    NASA Astrophysics Data System (ADS)

    Zhang, Guan-Jun; Yang, Kai; Dong, Ming; Zhao, Wen-Bin; Yan, Zhang

    2007-12-01

    Electroluminescence (EL) phenomena are closely linked to the space charge and degradation in insulating polymers, and dominated by the luminescence and trap centers. EL emission has been promising in defining the onset of electrical aging and in the investigation of dissipation mechanisms. Generally, polymeric degradation reveals the increment of the density of luminescence and trap centers, so a fundamental study is proposed to correlate the EL emission of insulating polymers and their trapping parameters. A sensitive photon counting system is constructed to detect the weak EL. The time- and phase-resolved EL characteristics from different polymers (LDPE, PP and PTFE) are investigated with a planar electrode configuration under stepped ac voltage in vacuum. In succession, each sample is charged with exposing to multi-needle corona discharge, and then its surface potential decay is continuously recorded at a constant temperature. Based on the isothermal relaxation current theory, the energy level and density of both electron and hole trap distribution in the surface layer of each polymer is obtained. It is preliminarily concluded that EL phenomena are strongly affected by the trap properties, and for different polymers, its EL intensity is in direct contrast to its surface trap density, and this can be qualitatively explained by the trapping and detrapping sequence of charge carriers in trap centers with different energy level.

  8. Investigations of fundamental phenomena in quantum mechanics with neutrons

    NASA Astrophysics Data System (ADS)

    Hasegawa, Yuji

    2014-04-01

    Neutron interferometer and polarimeter are used for the experimental investigations of quantum mechanical phenomena. Interferometry exhibits clear evidence of quantum-contextuality and polarimetry demonstrates conflicts of a contextual model of quantum mechanics la Leggett. In these experiments, entanglements are achieved between degrees of freedom in a single-particle: spin, path and energy degrees of freedom are manipulated coherently and entangled. Both experiments manifest the fact that quantum contextuality is valid for phenomena with matter waves with high precision. In addition, another experiment is described which deals with error-disturbance uncertainty relation: we have experimentally tested error-disturbance uncertainty relations, one is derived by Heisenberg and the other by Ozawa. Experimental results confirm the fact that the Heisenberg's uncertainty relation is often violated and that the new relation by Ozawa is always larger than the limit. At last, as an example of a counterfactual phenomenon of quantum mechanics, observation of so-called quantum Cheshire Cat is carried out by using neutron interferometer. Experimental results suggest that pre- and post-selected neutrons travel through one of the arms of the interferometer while their magnetic moment is located in the other arm.

  9. Different Selection Pressures Give Rise to Distinct Ethnic Phenomena

    PubMed Central

    Moya, Cristina; Boyd, Robert

    2015-01-01

    Many accounts of ethnic phenomena imply that processes such as stereotyping, essentialism, ethnocentrism, and intergroup hostility stem from a unitary adaptation for reasoning about groups. This is partly justified by the phenomena’s co-occurrence in correlational studies. Here we argue that these behaviors are better modeled as functionally independent adaptations that arose in response to different selection pressures throughout human evolution. As such, different mechanisms may be triggered by different group boundaries within a single society. We illustrate this functionalist framework using ethnographic work from the Quechua-Aymara language boundary in the Peruvian Altiplano. We show that different group boundaries motivate different ethnic phenomena. For example, people have strong stereotypes about socioeconomic categories, which are not cooperative units, whereas they hold fewer stereotypes about communities, which are the primary focus of cooperative activity. We also show that, despite the cross-cultural importance of ethnolinguistic boundaries, the Quechua-Aymara linguistic distinction does not strongly motivate any of these intergroup processes. PMID:25731969

  10. Scaling of Quench Front and Entrainment-Related Phenomena

    SciTech Connect

    Aumiller, D. L.; Hourser, R. J.; Holowach, M. J.; Hochreiter, L. E.; Cheung, F-B.

    2002-04-01

    The scaling of thermal hydraulic systems is of great importance in the development of experiments in laboratory-scale test facilities that are used to replicate the response of full-size prototypical designs. One particular phenomenon that is of interest in experimental modeling is the quench front that develops during the reflood phase in a PWR (Pressurized Water Reactor) following a large-break LOCA (Loss of Coolant Accident). The purpose of this study is to develop a scaling methodology such that the prototypical quench front related phenomena can be preserved in a laboratory-scale test facility which may have material, geometrical, fluid, and flow differences as compared to the prototypical case. A mass and energy balance on a Lagrangian quench front control volume along with temporal scaling methods are utilized in developing the quench front scaling groups for a phenomena-specific second-tier scaling analysis. A sample calculation is presented comparing the quench front scaling groups calculated for a prototypical Westinghouse 17 x 17 PWR fuel design and that of the geometry and material configuration used in the FLECHT SEASET series of experiments.

  11. Nonextensive Statistical Mechanics: Some Links with Astronomical Phenomena

    NASA Astrophysics Data System (ADS)

    Tsallis, Constantino; Tsallis, Constantino; Prato, Domingo; Plastino, Angel R.; Plastino, Angel R.

    2004-04-01

    A variety of astronomical phenomena appear to not satisfy the ergodic hypothesis in the relevant stationary state, if any. As such, there is no reason for expecting the applicability of Boltzmann Gibbs (BG) statistical mechanics. Some of these phenomena appear to follow, instead, nonextensive statistical mechanics. In the same manner that the BG formalism is based on the entropy S BG=-k? i p i ln p i, the nonextensive one is based on the form S q=k(1 -? i p i q)/(q- 1) (with S 1=S BG). The stationary states of the former are characterized by an exponential dependence on the energy, whereas those of the latter are characterized by an (asymptotic) power law. A brief review of this theory is given here, as well as of some of its applications, such as the solar neutrino problem, polytropic self-gravitating systems, galactic peculiar velocities, cosmic rays and some cosmological aspects. In addition to these, an analogy with the Keplerian elliptic orbits versus the Ptolemaic epicycles is developed, where we show that optimizing S q with a few constraints is equivalent to optimizing S BG with an infinite number of constraints.

  12. Fundamental radar properties. II. Coherent phenomena in space-time.

    PubMed

    Gabriel, Andrew K

    2008-01-01

    A previous publication [J. Opt. Soc. Am. A19, 946-956 (2002)] presented a general formulation of radiative systems based on special relativity, and properties of imaging radar were derived as examples. Complex and diverse properties of radar images were shown to have a simple and unified origin when viewed as lower-dimensional (temporal) projections of the space-time structure of a radar observation. A diagram was developed that could be manipulated for a simple, intuitive view of the underlying structure of radar observations and phenomena. That treatment is here extended to include coherent phenomena as they appear in the lower time dimensions of the image. Various known coherent properties of imaging radar and interferometry are derived. The formulation is shown to be a generalization of a conventional echo correlation and is extended to a second spatial dimension. From this perspective, coherent properties also have a surprisingly simple and unified structure; their observed complexity is somewhat illusory, also a consequence of projection onto the lower temporal dimension of the receiver. While this formulation and the rules governing it are quite different from the standard treatments, they have the considerable advantage of providing a much simpler, intuitive, and unified description of radiative (radar and optical) systems that is rooted in fundamental physics. PMID:18157218

  13. Ionospheric Phenomena and Low-Frequency Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Herne, D.; Kennewell, J.; Lynch, M.; Carrano, C.

    2014-05-01

    The Murchison Widefield Array radio telescope (MWA), situated on the Murchison Radio Observatory (MRO) in Western Australia, has recently commenced operations. This instrument operates over the frequency range 80-300 MHz. Further, the MRO is also the site chosen to host the low-frequency component of the Square Kilometre Array, radio telescope (SKA). Each instrument is susceptible to scintillation caused by fluctuations in ionospheric plasma density and Faraday rotation of incoming signals caused by the interaction of low-frequency radio waves with dissociated electrons in the ionosphere. Observations of these parameters over several years, across periods of both subdued and elevated solar activity have demonstrated markedly differing regimes. High-precision GPS systems, combined with purpose-written data acquisition software (SCINDA), have enabled investigation of various phenomena including the effect of solar storms on the ionosphere at highly resolved time-scales. We report on aspects of phenomena observed and their significance to low-frequency radio astronomy and note that conditions of very low scintillation encountered support the decision to site world-leading instruments on the MRO.

  14. Primary resistance phenomena to oncolytic measles vaccine viruses.

    PubMed

    Noll, Markus; Berchtold, Susanne; Lampe, Johanna; Malek, Nisar P; Bitzer, Michael; Lauer, Ulrich M

    2013-07-01

    Measles vaccine virus (MeV) has been shown to possess profound oncolytic capabilities. However, tumor cell resistance to MeV may endanger broad clinical success. Here, this hypothesis is underlined by our analysis of the NCI-60 tumor cell panel infected with a suicide gene-armed MeV vector (MeV-SCD). Quantification of the MeV-SCD-induced oncolytic effect exhibited a 50% rate of NCI-60 solid tumor cell lines being susceptible to MeV-SCD induced oncolysis. In contrast, nearly 40% of the NCI-60 tumor cell lines had to be categorized as partially resistant (exhibiting 50-75% remnant tumor cells) and six tumor cell lines even showed high resistance to MeV-SCD-induced oncolysis with remnant tumor cell masses >75%. According to our further analysis, these high-grade resistant tumor cell lines i) exhibited a high variation in primary infectability rates and also different patterns of alterations ii) in virus replication and iii) in interferon response. This diversity of virotherapy resistance phenomena seems to go along with the diversity of genetic and epigenetic changes accompanying malignant transformation. Of paramount clinical importance, this plethora of resistance phenomena was shown to be overcome in vitro by employment of an increased MOI together with addition of the prodrug 5-FC, thus exploiting the highly efficient suicide gene function of vector MeV-SCD used in this study. PMID:23612727

  15. Free-energy calculation methods for collective phenomena in membranes

    NASA Astrophysics Data System (ADS)

    Smirnova, Yuliya G.; Fuhrmans, Marc; Barragan Vidal, Israel A.; Müller, Marcus

    2015-09-01

    Collective phenomena in membranes are those which involve the co-operative reorganization of many molecules. Examples of these are membrane fusion, pore formation, bending, adhesion or fission. The time and length scales, on which these processes occur, pose a challenge for atomistic simulations. Therefore, in order to solve the length scale problem it is popular to introduce a coarse-grained representation. To facilitate sampling of the relevant states additional computational techniques, which encourage the system to explore the free-energy landscape far from equilibrium and visit transition states, are needed. These computational techniques provide insights about the free-energy changes involved in collective transformations of membranes, yielding information about the rate limiting states, the transformation mechanism and the influence of architectural, compositional and interaction parameters. A common approach is to identify an order parameter (or reaction coordinate), which characterizes the pathway of membrane reorganization. However, no general strategy exists to define such an order parameter that can properly describe cooperative reorganizations in membranes. Recently developed methods can overcome this problem of the order-parameter choice and allow us to study collective phenomena in membranes. We will discuss such methods as thermodynamic integration, umbrella sampling, and the string method and results provided by their applications to particle-based simulations, particularly focusing on membrane fusion and pore formation.

  16. PREFACE: Physics and Mathematics of Nonlinear Phenomena 2013 (PMNP2013)

    NASA Astrophysics Data System (ADS)

    Konopelchenko, B. G.; Landolfi, G.; Martina, L.; Vitolo, R.

    2014-03-01

    Modern theory of nonlinear integrable equations is nowdays an important and effective tool of study for numerous nonlinear phenomena in various branches of physics from hydrodynamics and optics to quantum filed theory and gravity. It includes the study of nonlinear partial differential and discrete equations, regular and singular behaviour of their solutions, Hamitonian and bi- Hamitonian structures, their symmetries, associated deformations of algebraic and geometrical structures with applications to various models in physics and mathematics. The PMNP 2013 conference focused on recent advances and developments in Continuous and discrete, classical and quantum integrable systems Hamiltonian, critical and geometric structures of nonlinear integrable equations Integrable systems in quantum field theory and matrix models Models of nonlinear phenomena in physics Applications of nonlinear integrable systems in physics The Scientific Committee of the conference was formed by Francesco Calogero (University of Rome `La Sapienza', Italy) Boris A Dubrovin (SISSA, Italy) Yuji Kodama (Ohio State University, USA) Franco Magri (University of Milan `Bicocca', Italy) Vladimir E Zakharov (University of Arizona, USA, and Landau Institute for Theoretical Physics, Russia) The Organizing Committee: Boris G Konopelchenko, Giulio Landolfi, Luigi Martina, Department of Mathematics and Physics `E De Giorgi' and the Istituto Nazionale di Fisica Nucleare, and Raffaele Vitolo, Department of Mathematics and Physics `E De Giorgi'. A list of sponsors, speakers, talks, participants and the conference photograph are given in the PDF. Conference photograph

  17. The Lattice-boltzmann method for simulating gaseous phenomena.

    PubMed

    Wei, Xiaoming; Li, Wei; Mueller, Klaus; Kaufman, Arie E

    2004-01-01

    We present a physically-based, yet fast and simple method to simulate gaseous phenomena. In our approach, the incompressible Navier-Stokes (NS) equations governing fluid motion have been modeled in a novel way to achieve a realistic animation. We introduce the Lattice Boltzmann Model (LBM), which simulates the microscopic movement of fluid particles by linear and local rules on a grid of cells so that the macroscopic averaged properties obey the desired NS equations. The LBM is defined on a 2D or 3D discrete lattice, which is used to solve fluid animation based on different boundary conditions. The LBM simulation generates, in real-time, an accurate velocity field and can incorporate an optional temperature field to account for the buoyancy force of hot gas. Because of the linear and regular operations in each local cell of the LBM grid, we implement the computation in commodity texture hardware, further improving the simulation speed. Finally, textured splats are used to add small scale turbulent details, achieving high-quality real-time rendering. Our method can also simulate the physically correct action of stationary or mobile obstacles on gaseous phenomena in real-time, while still maintaining highly plausible visual details. PMID:15384641

  18. Initiating Young Children into Basic Astronomical Concepts and Phenomena

    NASA Astrophysics Data System (ADS)

    Kallery, M.

    2010-07-01

    In the present study we developed and implemented three units of activities aiming at acquainting very young children with basic astronomical concepts and phenomena such as the sphericity of the earth, the earths movements and the day/night cycle. The activities were developed by a group composed of a researcher/facilitator and six early-years teachers. In the activities children were presented with appropriate for their age scientific information along with conceptual tools such as a globe and an instructional video. Action research processes were used to optimize classroom practices and to gather useful information for the final shaping of the activities and the instruction materials. In these activities the adopted approach to learning can be characterized as socially constructed. The results indicated awareness of concepts and phenomena that the activities dealt with in high percentages of children, storage of the new knowledge in the long term memory and easy retrieval of it, and childrens enthusiasm for the subject.

  19. Initial aging phenomena in copper-chromium alloys

    NASA Technical Reports Server (NTRS)

    Suzuki, H.; Motohiro, K.

    1985-01-01

    The effects of quenching and aging temperatures on the initial aging curves of Cu-Cr alloy were examined mainly by means of electrical resistivity measurements. Three Cu-Cr alloy specimens having 0.24, 0.74, and 1.0% Cr were solution-treated at 950-1050 C, quenched into ice-water, and subsequently aged at 300-500 C. The results were as follows: (1) At the very early stage of aging (within about 30 sec), an abrupt decrease of resistivity with lowering aging tempratures. (T sub A) and rising solution temperatures (T sub S) was observed at (T sub A) up to about 400 C. In contrast, a transient increase of resistivity with rising T sub A and lowering T sub S was observed at T sub A from about 450 to 500 C. These phenomena seem to be caused by a rapid formation of solute clusters and the reversion of clusters formed during quenching, which are enhanced by quenched-in vacancies, respectively. (2) The amount of precipitation increased at the latter stage of aging with rising T sub S and T sub A as generally expected, where T sub S was not so high as to form secondary defects. (3) As a result, the initial aging phenomena in Cr-Cr alloy were revealed to be complicated against expectations. This was considered to be due to the migration energy of vacancies so larger in Cu-base.

  20. Emergent Topological Phenomena in Thin Films of Pyrochlore Iridates

    NASA Astrophysics Data System (ADS)

    Yang, Bohm-Jung; Nagaosa, Naoto

    2014-06-01

    Because of the recent development of thin film and artificial superstructure growth techniques, it is possible to control the dimensionality of the system, smoothly between two and three dimensions. In this Letter we unveil the dimensional crossover of emergent topological phenomena in correlated topological materials. In particular, by focusing on the thin film of pyrochlore iridate antiferromagnets grown along the [111] direction, we demonstrate that the thin film can have a giant anomalous Hall conductance, proportional to the thickness of the film, even though there is no Hall effect in 3D bulk material. Moreover, in the case of ultrathin films, a quantized anomalous Hall conductance can be observed, despite the fact that the system is an antiferromagnet. In addition, we uncover the emergence of a new topological phase, the nontrivial topological properties of which are hidden in the bulk insulator and manifest only in thin films. This shows that the thin film of correlated topological materials is a new platform to search for unexplored novel topological phenomena.