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1

Oscillatory phenomena in solar and stellar atmospheres  

NASA Astrophysics Data System (ADS)

This thesis presents varying studies into the nature of intensity oscillations observed both on the Sun and two active cool stars. The first part concentrates on the detection of correlated oscillations occuring between differing heights in the solar atmosphere above quiet-Sun magnetic network bright points (NBPs), interpreted as signatures of energy propagation. This is achieved through correlating in time the wavelet power spectra of lightcurves from images obtained in several optical wavelengths. In four of the eleven NBPs studied, evidence is found for upwardly-propagating, low-frequency waves (1.4 mHz, 2.1 mHz) in the lower chromosphere, decreasing in oscillatory power with the onset, or increase in power, of higher-frequency waves (2.9 mHz, 4.0 mHz) within the upper chromosphere. Moving higher into the atmosphere two of the four cases of higher frequency waves also show a decrease in power. These observational detections are interpreted as transverse-mode magnetohydrodynamic (MHD) waves undergoing non-linear mode coupling to longitudinal-modes at double the frequency, which shock or otherwise dissipate in the high chromosphere. Evidence is also found for additional upward- and downward- directed waves within all the NBPs studied. The extension of wavelet power techniques into the analysis of phase difference and phase coherence is also presented, utilising UV intensities obtained from above a weak solar network element. The problems associated with the quantification of phase coherence values are outlined and a comparison of two differing methods is carried out. Changes observed in the evolution of phase difference between oscillations detected in the UV emission of the temperature minimum and low transition region are shown to be due to the alteration of the underlying magnetic topology, occuring when same polarity flux emerges nearby. The final part of this thesis concerns the differing situation of intensity variations during energetic flare phenomena on two active cool stars. Repeated fluctuations are analysed in broad-band optical flare emission from the RS CVn binary II Peg and the B component of binary star EQ Peg, yielding medium- (220 s) and short- (10 s) oscillation periods, respectively. These periods are discussed in terms of a simplified model of standing waves within a closed coronal loop. In both cases the observed decrease of oscillation period up to flare peak and subsequent increase during initial flare decay follows the inverse proportionality to loop temperature expected by the simple model.

Bloomfield, David Shaun

2

Effects of oceanic and atmospheric phenomena on precipitation and flooding in the Manafwa River Basin  

E-print Network

An investigation was performed to determine the relationship between certain oceanic and atmospheric phenomena and the precipitation patterns in the Manafwa River Basin of eastern Uganda. Such phenomena are the El Niño ...

Finney, William W., III (William Warner)

2014-01-01

3

Dynamics of pulse phenomena in helium dielectric-barrier atmospheric-pressure glow discharges  

E-print Network

. A relatively simple zero-dimensional model that treats only the Paschen breakdown mechanism in the dischargeDynamics of pulse phenomena in helium dielectric-barrier atmospheric-pressure glow discharges of pulse phenomena in conventional parallel-plate dielectric-barrier controlled atmospheric-pressure glow

Raja, Laxminarayan L.

4

Meteor phenomena in the planet's atmospheres. (Russian Title: ????????? ??????? ? ?????????? ??????)  

NASA Astrophysics Data System (ADS)

Ablation processes of meteor bodies in atmospheres of different planets are considered/ Lengths of meteors in atmospheres of giant planets much greater than in the Earth's atmosphere and the zenith attraction reaches 90 degrees.

Levin, B. Yu.; Simonenko, A. N.

1982-05-01

5

Double streamer phenomena in atmospheric pressure low frequency corona plasma  

SciTech Connect

Time-resolved images of an atmospheric pressure corona discharge, generated at 50 kHz in a single pin electrode source, show unique positive and negative corona discharge features: a streamer for the positive period and a glow for the negative period. However, unlike in previous reports of dc pulse and low frequency corona discharges, multistreamers were observed at the initial time stage of the positive corona. A possible physical mechanism for the multistreamers is suggested.

Kim, Dan Bee; Jung, H.; Gweon, B.; Choe, Wonho [Department of Physics, Korea Advanced Institute of Science and Technology, 335 Gwahangno, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

2010-07-15

6

Coupled ocean-atmosphere GCM simulation of Southern Oscillation phenomena  

SciTech Connect

The Oregon State University coupled upper ocean-atmosphere GCM has, been shown to qualitatively simulate the Southern Oscillation. A composite analysis of the warm and cold events simulated in this 23-year integration has been performed. During the low phase of the SO, when warm anomalies occur in the Eastern Pacific the model simulates for the Atlantic region during March--May (1) a deficit of precipitation over the tropical South American continent (2) Caribbean and Gulf of Mexico sea-level pressure and sea-surface temperature are in-phase with the Eastern Pacific anomalies, while those East of the Nordeste region are out-of-phase (3) northeast trade winds are anomalously weak and southwest trade winds are anomalously strong (as inferred from surface current anomalies). During the high phase of the simulated Southern Oscillation conditions in the atmosphere and ocean are essentially the reverse of the low phase. Thus the model produces a response in the South American region during the opposing phases of the Southern Oscillation which is in general agreement with observations.

Sperber, K.R. [Lawrence Livermore National Lab., CA (United States); Hameed, S. [State Univ. of New York, Stony Brook, NY (United States). Inst. for Terrestrial and Planetary Atmospheres

1992-07-01

7

Phenomena of oscillations in atmospheric pressure direct current glow discharges  

SciTech Connect

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.

Liu, Fu-cheng [College of Physics Science and Technology, Hebei University, Baoding 071002 (China)] [College of Physics Science and Technology, Hebei University, Baoding 071002 (China); Yan, Wen; Wang, De-zhen [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2013-12-15

8

PROPAGATING WAVE PHENOMENA DETECTED IN OBSERVATIONS AND SIMULATIONS OF THE LOWER SOLAR ATMOSPHERE  

SciTech Connect

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 A continuum formation heights of 100 km and 25 km, respectively. Detected magnetoacoustic oscillations exhibit a dominant phase delay of -8 Degree-Sign between the G-band and 4170 A 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.

Jess, D. B.; Shelyag, S.; Mathioudakis, M.; Keys, P. H.; Keenan, F. P. [Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN (United Kingdom); Christian, D. J., E-mail: d.jess@qub.ac.uk [Department of Physics and Astronomy, California State University Northridge, Northridge, CA 91330 (United States)

2012-02-20

9

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

NASA Technical Reports Server (NTRS)

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.

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

1977-01-01

10

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

NASA Astrophysics Data System (ADS)

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''.

Kokott, Wolfgang

11

Faint electric dynamic forces in atmosphere is a possible precursor for a Seismic events phenomena  

NASA Astrophysics Data System (ADS)

The objective of this paper is to monitor the propagation of faint electric forces (D.C. potentials) in Athens' atmosphere before an earthquake. Many authors refer to radio emissions (ELF,HF,VLF,UHF ) before an event. Several other researches have been done with ICE (Instrument Champ Electrique), measurement of quasi-continuous electric fields and electric components of waves, from DC up to 3.5 MHz, or IMSC (Measuring the magnetic components of waves), for measuring magnetic field from a few Hz up to 18 kHz. More studies, within the last twenty years are correlated also with monitoring underground electromagnetic fields from different countries, but few are dealing with D.C.field. The concept is that, the aerosols are injected into the lower atmosphere due to intensifying soil gas content during the increase of seismic activity. At our station in Athens, a continuous monitoring has been conducted by three D.C.detectors which follow the ionosphere variations of the electric field daily, for the years 2007-2008. Multiple antennas have been posted and tested up to the height of thirty meters above the ground. The faint electro potentials received, had been continuously registered by two electrometers. A cross over study of aerosols simulation has been simultaneously done with photo detectors. For this purpose an array of four photo diodes, posted in infrared and visible band in function, and was connected to electro meters too. Several approaches have been taken in past years by researchers attempting to correlate changes in geophysical parameters with earthquake phenomena. In particular, many works examine possible connections of Geoelectric Field (Long and Sort Term Geoelectric Potential) variations to seismic activity and their possible use as precursors of seismic events. Long Term Geoelectric Potential (LTGP) acquisition data consists of potential difference measured between pairs of electrodes placed in the ground at specific location and distance. The electric field is continuously monitored, usually in two perpendicular directions (e.g. N-S and E-W), by two pairs of electrodes, each corresponding to a separate channel. Here we examine such possible correlations between recorded Long Term Geoelectric Potential (LTGP) acquisition data and the seismic activity observed during the same period. In collaboration with the University of Athens, Laboratory of Climatology and Atmospheric Environment and according their given data, we avoided measurements during periods of rain, snow, storms, lightning or extreme variations of temperature and atmospheric pressure. During these observations we observed an enormous variation in the voltage signals and several potential peaks were registered before the quakes in both detectors and photodiodes. The variations noted before the events, become with an optimum peak between four hours to fourteen days. All cases are related with eight earthquakes, registered in the southern part of Greece. Our conclusions demonstrate that charged aerosol emissions in the atmosphere are possible to influence and increase electro potentials before an earthquake event, under certain atmospheric conditions.

Grigoropoulos, K. N.; Nastos, P. T.; Tselentis, G.; Saragas, E.; Ifantis, A.

2009-04-01

12

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

NASA Astrophysics Data System (ADS)

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.

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

2014-12-01

13

Absorption phenomena of solar XUV-radiation by upper Earth atmosphere in the numerical model of the neutral atmosphere WMA01  

NASA Astrophysics Data System (ADS)

The numerical model of a neutral Earth's atmosphere - working model of atmosphere 2001 (WMA01), designed in Institute of the Terrestrial Magnetism, Ionosphere and Radiovawe Propagation, was corrected on the basis of the data of atmospheric sounding in X-ray range. The absorption phenomena by a Earth's atmosphere of solar XUV-radiation observed in the Sun's images obtained by a telescope TEREK-K (Space Vehicle "Koronas-I") in May-June 1994 at low activity of the Sun and instrumentation SPIRIT (Space Vehicle "Koronas-F") in October - November 2001 in a maximum of activity are studied in this research. The images of the Sun were registered on orbit segments when satellites moving in a shadow of the Earth and en satellites moving out of a shadow. So the upper Earth's atmosphere was sounded at altitudes 100 - 500 kms. The telescope TEREK-K was tuning on spectrum range 175 A and 304 A. The scientific equipment SPIRIT were tuning on spectrum range 175, 304 and 8,42 A. Integral value of absorption, direction of a density gradient of atmosphere, the local variations of absorption on an altitude to scale 1 km can be obtained by using of this technique. This method can essential supplement traditional techniques of research of the upper atmosphere and ionospheres.

Boyarchuk, K. A.; Zhitnik, I. A.; Ivanov-Kholodny, G. S.; Karelin, A. V.; Kolomiitsev, O. P.; Kuzin, S. V.; Trushin, A. S.

14

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

NASA Astrophysics Data System (ADS)

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.

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

15

The atmosphere UV background phenomena measured by detector on-board ``Tatiana'' satellite  

NASA Astrophysics Data System (ADS)

Near UV detector on-board the “Universitetsky-Tatiana” satellite has observed the atmosphere glow at night side of the Earth. Digital oscilloscopes help to select transient luminous events and to measure their temporal profiles in time scale of 1-64 ms. Data from those detectors were analyzed for prediction the duty cycle of future space detectors of ultra high energy cosmic rays.

Klimov, P. A.; Garipov, G. K.; Khrenov, B. A.; et al.

16

Modeling of asymmetric pulsed phenomena in dielectric-barrier atmospheric-pressure glow discharges  

SciTech Connect

Asymmetric current pulses in dielectric-barrier atmospheric-pressure glow discharges are investigated by a self-consistent, one-dimensional fluid model. It is found that the glow mode and Townsend mode can coexist in the asymmetric discharge even though the gas gap is rather large. The reason for this phenomenon is that the residual space charge plays the role of anode and reduces the gap width, resulting in the formation of a Townsend discharge.

Ha Yan [College of Mathematics and Computer Science, Hebei University, Baoding 071002 (China); Wang Huijuan [School of Mathematics and Physics, North China Electric Power University, Baoding 071003 (China); Wang Xiaofei [College of Physics Science and Technology, Hebei University, Baoding 071002 (China)

2012-01-15

17

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

NASA Technical Reports Server (NTRS)

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

Hansteen, V. H.

1997-01-01

18

Modeling of ocean-atmosphere interaction phenomena during the breaking of modulated wave trains  

NASA Astrophysics Data System (ADS)

Air water interaction phenomena taking place during the breaking of ocean waves are investigated here. The study is carried out by exploiting the combination between a potential flow method, which is used to describe the evolution of the wave system up to the onset of the modulational instability, and a two-fluids Navier-Stokes solver which describes the strongly non-linear air-water interaction taking place during breaking events. The potential flow method is based on a fully non-linear mixed Eulerian-Lagrangian approach, whereas the two-fluid model uses a level-set method for the interface capturing. The method is applied to study the evolution of a modulated wave train composed by a fundamental wave component with two side band disturbances. It is shown that breaking occurs when the initial steepness exceed a threshold value. Once the breaking starts, it is not just a single event but it is recurrent with a period associated to the group velocity. Results are presented in terms of free surface shapes, velocity and vorticity fields, energy and viscous dissipation. The analysis reveals the formation of large vortex structures in the air domain which are originated by the separation of the air flow at the crest of the breaking wave. The form drag associated to the flow separation process significantly contributes to the dissipation of the energy content of the wave system. The energy fraction dissipated by each breaking event is distinguished.

Iafrati, A.; Babanin, A.; Onorato, M.

2014-08-01

19

Abnormal winter weather in Japan during 2012 controlled by large-scale atmospheric and small-scale oceanic phenomena  

NASA Astrophysics Data System (ADS)

Negative Arctic Oscillation (AO) and Western Pacific (WP) pattern indices persisted from October through December 2012. For the first time both the monthly AO and WP were negative for three consecutive months. Although negative AOs and WPs make Siberia, Eastern Asia, and Japan abnormally cold, Japan was warm in October 2012. The temperature of the Sea of Japan was a record-breaking high in October 2012. Heating by these very warm waters overwhelmed the cooling effect of the negative AO and WP in October, even though the Sea of Japan is small. Linear regression analyses showed that Japan tends to be warm in years when the Sea of Japan is warm. Consequently, the temperature over Japan is 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.

Ando, Yuta; Ogi, Masayo; Tachibana, Yoshihiro

2014-05-01

20

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

NASA Astrophysics Data System (ADS)

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.

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

2014-09-01

21

The TUS space fluorescence detector for study of UHECR and other phenomena of variable fluorescence light in the atmosphere  

NASA Astrophysics Data System (ADS)

The Tracking Ultraviolet Set Up (TUS) instrument has been designed to observe from space the fluorescence light in the atmosphere when Extensive Air Shower (EAS) or other phenomena such as meteors or dust grains traverse it. The TUS design concepts will allow us to construct the next generation of fluorescence detectors with increasing light collection power and higher resolution. The KLYPVE instrument with collection power 5 times larger of the TUS will be the next space detector. Light collection is obtained with the help of segmented “low frequency Fresnel type” mirrors. Photo receiver retina in the focal consists of modules of PM tubes. For stable performance in conditions of variable light noise and variable temperature the tube type with a multi-alcali cathode was chosen. Voltage supplies for PMT in one module were designed for keeping the performance of photo receiver retina uniform when the tube gain change. From every tube the signal amplitude is recorded in time bins of 400 ns. The digital data are kept and analyzed in the module FPGA connected to the central FPGA controlling all data. The RAM memory is large, capable to record events with different duration of the light signal (up to several seconds). The preliminary event data are analyzed in the triggering system of the central FPGA. The trigger criteria have several options for events of different origin (different pixel signal duration). The trigger integration time is controlled from the space mission center. The performances of the detector were simulated and zenith angle dependent trigger efficiencies were calculated. The TUS detector will be efficient in recording “horizontal” EAS (zenith angles more than 60°), developed to their maximum above the cloud cover. The EAS Cherenkov light, back scattered from the cloud cover, will be recorded and will improve data on the EAS direction and position of maximum. For better accuracy in physical parameters of the events and for the experimental check of this accuracy the performance of two TUS detectors at the space platform was recommended. The accommodation of 2 TUS detectors at space platform of the “RESURS O” type was tried and approved. The TUS prototypes are being tested in the Mexican mountains. The photo receiver of two PM tubes with the TUS electronics on-board of the MSU Tatiana satellite is measuring the atmosphere light background.

Abrashkin, V.; Alexandrov, V.; Arakcheev, Y.; Bitkin, E.; Cordero, A.; Eremin, S.; Finger, M.; Garipov, G.; Grebenyuk, V.; Kalmykov, N.; Khrenov, B.; Koval, V.; Martinez, O.; Matyushkin, A.; Moreno, E.; Naumov, D.; Olshevsky, A.; Panasyuk, M.; Park, I.; Robledo, C.; Rubinstein, I.; Sharakin, S.; Silaev, A.; Tkatchev, L.; Tulupov, V.; Tyukaev, R.; Sabirov, B.; Salazar, H.; Saprykin, O.; Syromyatnikov, V.; Urmantsev, F.; Villasenor, L.; Yashin, I.; Zaikin, N.; Zepeda, A.

22

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

NASA Astrophysics Data System (ADS)

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.

Gitle Hauge, Bjørn; Strand, Erling

2013-04-01

23

Atmospheric and ionospheric phenomena related to anomalous VHF-band radio wave transmissions beyond the line of sight  

NASA Astrophysics Data System (ADS)

We have monitored anomalous VHF-band radio wave transmissions received beyond the line of sight prior to earthquakes since 2003 in Hokkaido, northern Japan, to determine the relationship between anomalous transmission of VHF-band radio waves and impending earthquakes. Anomalous VHF-band radio waves were recorded before some medium and large earthquakes of magnitude 4 or higher. Radio waves transmitted from a specific FM radio station are considered to have been scattered in the atmosphere, allowing the radio waves to be received by an observation station beyond the line of sight of the transmitter. One hypothesis to explain the pre-earthquake anomalous radio transmissions is that radon gas emanates from the surface as a result of increasing fluid pressure during the preparation process of an earthquake. The radon release increases the density of small ions and the atmospheric conductivity and decreases the atmospheric electric field in the lower atmosphere. To confirm the process, we monitored the atmospheric electric field at the VHF radio wave monitoring site. Variations in the atmospheric electric field accompanied by anomalous radio wave transmissions were observed at times. Additionally, larger anomalous transmission may be caused by the sporadic E layer of the ionosphere in the early summer season. The sporadic E anomalies overlap anomalies associated with earthquakes and can be distinguished as a distinct feature.

Mogi, T.; Kakinami, Y.; Moriya, T.

2013-12-01

24

Energetic Particles Impacting the Upper Atmosphere in Connection with Transient Luminous Event Phenomena: Russian Space Experiment Programs  

NASA Astrophysics Data System (ADS)

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.

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

2009-04-01

25

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)

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.

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

1974-01-01

26

Paranormal phenomena  

NASA Astrophysics Data System (ADS)

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.

Gaina, Alex

1996-08-01

27

Empirical substantiation of possible connection between content radiocarbon in atmosphere and frequency of the catastrophic phenomena in Europe in last millennium (on the basis of historical records or annals)  

NASA Astrophysics Data System (ADS)

The method of research of frequency of the natural catastrophic phenomena and processes in territory of Ukraine, the Western Europe and Russian (East-Europe) plain in last millennium was worked out on the basis of the analysis of historical records or annals. Empirical time series of frequency of the catastrophic weather phenomena in territory of Ukraine for the period of 800-1800 (droughts, rainy summers, floods and high waters, cold winters, late springs, colds at the beginning of a summer, catastrophic thunderstorms, catastrophic storms, earthquakes etc.) are constructed. The anomalies of temperature of Europe for last millennium were also considered. Non-monotonic connection of frequency of catastrophic processes and the phenomena on territory of Ukraine with global anomalies of content of radiocarbon in atmosphere in last millennium is established. The basic result of this research is: frequency of catastrophic natural phenomena in the territory of Europe was higher, when the anomalies of content of radiocarbon in atmosphere deviated in this or that direction from some optimum level. A quantitative estimation of the established effect are obtained with help for a parabolic model of dependence of frequency of phenomena from of century anomalies of content of radiocarbon in atmosphere in Europe. Estimations of empirical constants of this mathematical model for all considered phenomena are received. It is known, that the content of radiocarbon in an atmosphere is one of indicators of long-term solar activity. The hypothesis earlier offered by another scientists concerning connections between century temperature anomalies in Europe and long-terms cycles of solar activity is considered. Unfortunately, the radiocarbon indicator of solar activity is essentially spoiled by anthropogenic influence (Suess's effect, bomb-effect) for last ~150 years. As a basic result of this research semi-empirical model of parabolic dependence of frequency of the catastrophic phenomena in Europe from index of solar and geophysical anomalies (content of radiocarbon) is obtained.

Boychenko, S. G.; Voloshchuk, V. M.

28

Atmosphere  

NSDL National Science Digital Library

What is this atmosphere that surrounds the Earth? This instructional tutorial, part of an interactive laboratory series for grades 8-12, introduces students to the structure, effects, and components of the atmosphere. Here students investigate the composition of the atmosphere; effects of temperature, pressure, and ozone; the greenhouse effect; and how Earth compares with other planets. Interactive activities present students with opportunities to explore ideas and answer questions about the atmosphere, including its structure, the making of ozone, rocket launching, and measuring the atmosphere. Pop-up boxes provide additional information on topics such as dust, rain, and atmospheric composition. Students complete a final written review of six questions about the atmosphere. Copyright 2005 Eisenhower National Clearinghouse

University of Utah. Astrophysics Science Project Integrating Research and Education (ASPIRE)

2003-01-01

29

Transport Phenomena.  

ERIC Educational Resources Information Center

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)

McCready, Mark J.; Leighton, David T.

1987-01-01

30

Atmospheres  

NASA Astrophysics Data System (ADS)

When high Al containing Fe alloys such as TRIP steels are exposed to atmospheres that contain N2 during re-heating, sub-surface nitrides form and these can be detrimental to mechanical properties. Nitride precipitation can be controlled by minimizing the access of the gaseous atmosphere to the metal surface, which can be achieved by a rapid growth of a continuous and adherent surface scale. This investigation utilizes a Au-image furnace attached to a confocal scanning microscope to simulate the annealing temperature vs time while Fe-Al alloys (with Al contents varying from 1 to 8 wt pct) are exposed to a O2-N2 atm with 10-6 atm O2. The heating times of 1, 10, and 100 minutes to the isothermal temperature of 1558 K (1285 °C) were used. It was found that fewer sub-surface nitride precipitates formed when the heating time was lowered and when Al content in the samples was increased. In the 8 wt pct samples, no internal nitride precipitates were present regardless of heating time. In the 3 and 5 wt pct samples, internal nitride precipitates were nearly more or less absent at heating times less than 10 minutes. The decrease in internal precipitates was governed by the evolving structure of the external oxide-scale. At low heating rates and/or low Al contents, significant Fe-oxide patches formed and these appeared to allow for ingress of gaseous N2. For the slow heating rates, ingress could have happened during the longer time spent in lower temperatures where non-protective alumina was present. As Al content in the alloy was increased, the external scale was Al2O3 and/or FeAl2O4 and more continuous and consequently hindered the N2 from accessing the metal surface. Increasing the Al content in the alloy had the effect of promoting the outward diffusion of Al in the alloy and thereby assisting the formation of the continuous external layer of Al2O3 and/or FeAl2O4.

Bott, June; Yin, Hongbin; Sridhar, Seetharaman

2014-12-01

31

Thermal Wave Phenomena  

NASA Technical Reports Server (NTRS)

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.

1999-01-01

32

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

33

Single event phenomena in atmospheric neutron environments  

Microsoft Academic Search

Describes 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 are presented, as well as measurements of charge collection in silicon test structures as a function of neutron energy.

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

1993-01-01

34

Empirical substantiation of possible connection between content radiocarbon in atmosphere and frequency of the catastrophic phenomena in Europe in last millennium (on the basis of historical records or annals)  

Microsoft Academic Search

The method of research of frequency of the natural catastrophic phenomena and processes in territory of Ukraine, the Western Europe and Russian (East-Europe) plain in last millennium was worked out on the basis of the analysis of historical records or annals. Empirical time series of frequency of the catastrophic weather phenomena in territory of Ukraine for the period of 800-1800

S. G. Boychenko; V. M. Voloshchuk

2004-01-01

35

Science and Paranormal Phenomena  

E-print Network

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 {\\it defined} as contradicting physics.

Noyes, H P

1999-01-01

36

Science and Paranormal Phenomena  

E-print Network

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 {\\it defined} as contradicting physics.

H. Pierre Noyes

1999-06-03

37

Science and Paranormal Phenomena  

SciTech Connect

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.

Noyes, H. Pierre

1999-06-03

38

Ion exchange phenomena  

SciTech Connect

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).

Bourg, I.C.; Sposito, G.

2011-05-01

39

Dynamic phenomena in sunspots  

NASA Technical Reports Server (NTRS)

A detailed summary of observed dynamic phenomena associated with sunspots is presented, together with a description of the observational techniques and available analytical formulations for the processes under study. The phenomena detected thus far are grouped into aperiodic events and oscillations and waves. Aperiodic phenomena comprise umbral flares, the superpenumbra, and inverse Evershed flow. Internal, aperiodic manifestations include penumbral grains, the photospheric penumbral dark fibrils, Evershed flow, umbral dots, the inhomogeneity of the umbral magnetic field, and umbral turbulence. Oscillations and flashes are seen in the umbra, while running waves and dark puffs have been detected in the penumbra, and oscillations are located in the photosphere. All the observed features are evidence of mass motion and change on time scales of less than an hour.

Moore, R. L.

1981-01-01

40

Flow phenomena in turbomachines  

NASA Astrophysics Data System (ADS)

This report describes work carried out at the Gas Turbine Laboratory at MIT during the period 10/20/89 - 10/19/92, as part of our multi-investigator effort on basic unsteady flow phenomena in turbomachines. Within the overall project four separate tasks are specified. These are, in brief: (1) The Influence of Inlet Temperature Nonuniformities on Turbine Heat Transfer and Dynamics; (2) Assessment of Unsteady Losses in Stator/ Rotor Interactions; (3) Unsteady Phenomena and Flowfield instabilities in Multistage Axial Compressors; (4) Vortex Wake-Compressor Blade Interaction in Cascades - A New Rapid Method for Unsteady Separation and Vorticity Flux Calculations.

Creitzer, E. M.; Epstein, A. H.; Giles, M. B.; McCune, J. E.; Tan, C. S.

1993-01-01

41

Imaging of snapping phenomena  

PubMed Central

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

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

2012-01-01

42

Meteor Phenomena and Bodies  

Microsoft Academic Search

Meteoroids can be observed at collision with the Earth's atmosphere as meteors. Different methods of observing meteors are\\u000a presented: besides the traditional counts of individual events, exact methods yield also data on the geometry of the atmospheric\\u000a trajectory; on the dynamics and ablation of the body in the atmosphere; on radiation; on the spectral distribution of radiation;\\u000a on ionization; on

Zden?k Ceplecha; Ji?Í Borovi?ka; W. Graham Elford; Douglas O. ReVelle; Robert L. Hawkes; VladimÍr Porub?an; Miloš Šimek

1998-01-01

43

Neutron Star Phenomena  

NASA Technical Reports Server (NTRS)

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.

Ruderman, Malvin

1998-01-01

44

Solar cosmic ray phenomena  

Microsoft Academic Search

This review attempts to present an integrated view of the several types of solar cosmic ray phenomena. The relevant large and small scale properties of the interplanetary medium are first surveyed, and their use in the development of a quantitative understanding of the cosmic ray propagation processes summarised. Solar cosmic ray events, in general, are classified into two phenomenological categories:

K. G. McCracken; U. R. Rao

1970-01-01

45

Monsoon circulation and atmospheric ozone  

NASA Astrophysics Data System (ADS)

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

Khrgian, A. Kh.; Nguyen, Van Thang

1991-01-01

46

Membrane Transport Phenomena (MTP)  

NASA Technical Reports Server (NTRS)

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.

Mason, Larry W.

1997-01-01

47

Electroosmotic Phenomena in Fractures  

Microsoft Academic Search

Electroosmotic phenomena in fractures have been investigated in the linear limit for various double-layer thicknesses. The effects of the geometrical parameters were systematically studied for deterministic sinusoidal and random self-affine fractures. The numerical results show a definite influence of the surface amplitude on electroosmotic processes. For self-affine fractures, the roughness or Hurst exponent has a much larger incidence than the

S. Marino; D. Coelho; S. Békri; P. M. Adler

2000-01-01

48

LABORATORY VIII NUCLEAR PHENOMENA  

E-print Network

. In addition the earth is bombarded by high energy protons which collide with the atmosphere and produce are more sensitive to radiation than others. After all, you may want to have children some day. To address

Minnesota, University of

49

MULTISCALE PHENOMENA IN MATERIALS  

SciTech Connect

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.

A. BISHOP

2000-09-01

50

Time-Variable Phenomena in the Jovian System  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

51

Weld pool phenomena  

SciTech Connect

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.

David, S.A.; Vitek, J.M.; Zacharia, T. [Oak Ridge National Lab., TN (United States); DebRoy, T. [Pennsylvania State Univ., University Park, PA (United States)

1994-09-01

52

PREFACE Integrability and nonlinear phenomena Integrability and nonlinear phenomena  

NASA Astrophysics Data System (ADS)

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

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

2010-10-01

53

Arcjet cathode phenomena  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

54

Arcjet Cathode Phenomena  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

55

ON DETECTING TRANSIENT PHENOMENA  

SciTech Connect

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.

Belanger, G., E-mail: gbelanger@sciops.esa.int [European Space Astronomy Centre (ESA/ESAC), Science Operations Department, Villanueva de la Canada (Madrid) (Spain)

2013-08-10

56

Hypervelocity impact phenomena  

SciTech Connect

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.

Chhabildas, L.C.

1995-07-01

57

Positron impact ionization phenomena  

NASA Astrophysics Data System (ADS)

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).

Murtagh, Daniel James

58

Teaching Optical Phenomena with Tracker  

ERIC Educational Resources Information Center

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…

Rodrigues, M.; Carvalho, P. Simeão

2014-01-01

59

Critical phenomena in complex networks  

E-print Network

The combination of the compactness of networks and their complex architectures results in a variety of critical effects dramatically different from those in cooperative systems on lattices. In the last few years, researchers have made important steps toward understanding the qualitatively new critical phenomena in complex networks. We review the results, concepts, and methods of this rapidly developing field. Here we mostly consider two closely related classes of these critical phenomena, namely structural phase transitions in the network architectures and transitions in cooperative models on networks as substrates. We also discuss systems where a network and interacting agents on it influence each other. We overview a wide range of critical phenomena in equilibrium and growing networks including the birth of the giant connected component, percolation, k-core percolation, phenomena near epidemic thresholds, condensation transitions, critical phenomena in spin models placed on networks, synchronisation, and se...

Dorogovtsev, S N; Mendes, J F F

2007-01-01

60

Misconceptions of Emergent Semiconductor Phenomena  

NASA Astrophysics Data System (ADS)

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

Nelson, Katherine G.

61

Teaching optical phenomena with Tracker  

NASA Astrophysics Data System (ADS)

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

Rodrigues, M.; Simeão Carvalho, P.

2014-11-01

62

Critical phenomena in complex networks  

E-print Network

The combination of the compactness of networks, featuring small diameters, and their complex architectures results in a variety of critical effects dramatically different from those in cooperative systems on lattices. In the last few years, researchers have made important steps toward understanding the qualitatively new critical phenomena in complex networks. We review the results, concepts, and methods of this rapidly developing field. Here we mostly consider two closely related classes of these critical phenomena, namely structural phase transitions in the network architectures and transitions in cooperative models on networks as substrates. We also discuss systems where a network and interacting agents on it influence each other. We overview a wide range of critical phenomena in equilibrium and growing networks including the birth of the giant connected component, percolation, k-core percolation, phenomena near epidemic thresholds, condensation transitions, critical phenomena in spin models placed on networks, synchronization, and self-organized criticality effects in interacting systems on networks. We also discuss strong finite size effects in these systems and highlight open problems and perspectives.

S. N. Dorogovtsev; A. V. Goltsev; J. F. F. Mendes

2007-11-16

63

Rendering Ghost Ships and Other Phenomena in Arctic Atmospheres  

E-print Network

ghost ship legends), the Fata Morgana or the Novaya-Zemlya effect. We present here an implementation Morgana or the Novaya-Zemlya remain mostly unknown. We present here our ray tracing method to reproduce

Gutierrez, Diego

64

HOT+COLD : physical and atmospheric phenomena in the Antarctic  

E-print Network

Utopias have historically been perceived as instruments of societal change, while prior manifestations have normally been attributed to emerging cultural conditions or evolving ethical views, however one of the most pertinent ...

Morris, Eric Randall

2014-01-01

65

Transport Phenomena and Materials Processing  

NASA Astrophysics Data System (ADS)

An extremely useful guide to the theory and applications of transport phenomena in materials processing This book defines the unique role that transport phenomena play in materials processing and offers a graphic, comprehensive treatment unlike any other book on the subject. The two parts of the text are, in fact, two useful books. Part I is a very readable introduction to fluid flow, heat transfer, and mass transfer for materials engineers and anyone not yet thoroughly familiar with the subject. It includes governing equations and boundary conditions particularly useful for studying materials processing. For mechanical and chemical engineers, and anyone already familiar with transport phenomena, Part II covers the many specific applications to materials processing, including a brief description of various materials processing technologies. Readable and unencumbered by mathematical manipulations (most of which are allocated to the appendixes), this book is also a useful text for upper-level undergraduate and graduate-level courses in materials, mechanical, and chemical engineering. It includes hundreds of photographs of materials processing in action, single and composite figures of computer simulation, handy charts for problem solving, and more. Transport Phenomena and Materials Processing: * Describes eight key materials processing technologies, including crystal growth, casting, welding, powder and fiber processing, bulk and surface heat treating, and semiconductor device fabrication * Covers the latest advances in the field, including recent results of computer simulation and flow visualization * Presents special boundary conditions for transport phenomena in materials processing * Includes charts that summarize commonly encountered boundary conditions and step-by-step procedures for problem solving * Offers a unique derivation of governing equations that leads to both overall and differential balance equations * Provides a list of publicly available computer programs and publications relevant to transport phenomena in materials processing

Kou, Sindo

1996-10-01

66

Scaling law in thermal phenomena  

E-print Network

In this paper the scaling law for the relaxation times in thermal phenomena is investigated. It is shown that dependent on the value of the parameter K=E/m(c\\alpha)^2,where E is the energy which is delivered to the system, m is the parton mass and \\alpha=1/137 for electromagnetic interaction and \\alpha=0.16 for strong interaction respectively, heat transport is diffusive, for K1. For the system with N partons the relaxation time is scaled as \\tau^N\\to N (\\hbar/(mc\\alpha)^2). Key words: Thermal phenomena, scaling

M. Kozlowski; J. Marciak-Kozlowska

2006-10-29

67

Abnormal pressures as hydrodynamic phenomena  

USGS Publications Warehouse

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

Neuzil, C.E.

1995-01-01

68

The Regional Atmospheric Modeling System (RAMS): Development for Parallel Processing Computer  

E-print Network

) of the planetary boundary layer. Its most frequent applications are to simulate atmospheric phenomenaThe Regional Atmospheric Modeling System (RAMS): Development for Parallel Processing Computer. Walko Department of Atmospheric Science, Colorado State University and Mission Research Corporation

Cirne, Walfredo

69

Graphene tests of Klein phenomena  

E-print Network

Graphene is characterized by chiral electronic excitations. As such it provides a perfect testing ground for the production of Klein pairs (electron/holes). If confirmed, the standard results for barrier phenomena must be reconsidered with, as a byproduct, the accumulation within the barrier of holes.

Stefano De Leo; Pietro Rotelli

2012-02-07

70

Virtual Physics Laboratory: Wave Phenomena  

NSDL National Science Digital Library

This site from Northwestern University discusses wave phenomena. The site features interactive applets of various wave types, including longitudinal, transverse, mixed, and sound waves. Also included are animations of superposition, beat frequencies, and the distinction between phase and group velocities, wave packets, and wave reflections.

The Department of Physics and Astronomy

71

Nuclear pairing: basic phenomena revisited  

E-print Network

I review the phenomena associated with pairing in nuclear physics, most prominently the ubiquitous presence of odd-even mass differences and the properties of the excitation spectra, very different for even-even and odd-A nuclei. There are also significant dynamical effects of pairing, visible in the inertias associated with nuclear rotation and large-amplitude shape deformation.

G. F. Bertsch

2012-03-25

72

Transport phenomena at metal surfaces  

Microsoft Academic Search

Previous theoretical treatments of the scattering of conduction electrons at surfaces are reviewed and it is found that a more complete theory is necessary if the effects of surface scattering in transport phenomena are to be adequately understood. The boundary condition for the distribution function is derived and analysed in terms of the angle-dependent scattering probability. The skin effect, cyclotron

L. A. Falkovsky

1983-01-01

73

Gravitational Anomaly and Transport Phenomena  

Microsoft Academic Search

Quantum anomalies give rise to new transport phenomena. In particular, a magnetic field can induce an anomalous current via the chiral magnetic effect and a vortex in the relativistic fluid can also induce a current via the chiral vortical effect. The related transport coefficients can be calculated via Kubo formulas. We evaluate the Kubo formula for the anomalous vortical conductivity

Karl Landsteiner; Eugenio Megías; Francisco Pena-Benitez

2011-01-01

74

Visualizing Chemical Phenomena in Microdroplets  

ERIC Educational Resources Information Center

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…

Lee, Sunghee; Wiener, Joseph

2011-01-01

75

Global atmospheric changes.  

PubMed Central

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

Piver, W T

1991-01-01

76

Middle Atmosphere Program. Handbook for MAP, Volume 10  

NASA Technical Reports Server (NTRS)

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.

Taubenheim, J. (editor)

1984-01-01

77

Undergraduates Understanding of Cardiovascular Phenomena  

NSDL National Science Digital Library

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

PhD Joel A. Michael (Rush Medical College Department of Molecular Biophysics and Physiology)

2002-06-01

78

Transport phenomena in nanoporous materials.  

PubMed

Diffusion, that is, the irregular movement of atoms and molecules, is a universal phenomenon of mass transfer occurring in all states of matter. It is of equal importance for fundamental research and technological applications. The present review deals with the challenges of the reliable observation of these phenomena in nanoporous materials. Starting with a survey of the different variants of diffusion measurement, it highlights the potentials of "microscopic" techniques, notably the pulsed field gradient (PFG) technique of NMR and the techniques of microimaging by interference microscopy (IFM) and IR microscopy (IRM). Considering ensembles of guest molecules, these techniques are able to directly record mass transfer phenomena over distances of typically micrometers. Their concerted application has given rise to the clarification of long-standing discrepancies, notably between microscopic equilibrium and macroscopic non-equilibrium measurements, and to a wealth of new information about molecular transport under confinement, hitherto often inaccessible and sometimes even unimaginable. PMID:25123096

Kärger, Jörg

2015-01-12

79

Emergent Phenomena via Molecular Dynamics  

NASA Astrophysics Data System (ADS)

Emergent phenomena are unusual because they are not obvious consequences of the design of the systems in which they appear, a feature no less relevant when they are being simulated. Several systems that exhibit surprisingly rich emergent behavior, each studied by molecular dynamics (MD) simulation, are described: (i) Modeling self-assembly processes associated with virus growth reveals the ability to achieve error-free assembly, where paradoxically, near-maximum yields are due to reversible bond formation. (ii) In fluids studied at the atomistic level, complex hydrodynamic phenomena in rotating and convecting fluids - the Taylor- Couette and Rayleigh-Bénard instabilities - can be reproduced, despite the limited length and time scales accessible by MD. (iii) Segregation studies of granular mixtures in a rotating drum reproduce the expected, but counterintuitive, axial and radial segregation, while for the case of a vertically vibrated layer a novel form of horizontal segregation is revealed.

Rapaport, D. C.

80

New phenomena searches at CDF  

SciTech Connect

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.

Soha, Aron; /UC, Davis

2006-04-01

81

Visualization of solidification front phenomena  

NASA Technical Reports Server (NTRS)

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.

Workman, Gary L.; Smith, Guy A.

1993-01-01

82

Mathematical Modeling of Diverse Phenomena  

NASA Technical Reports Server (NTRS)

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.

Howard, J. C.

1979-01-01

83

TRANSIENT LUNAR PHENOMENA: REGULARITY AND REALITY  

SciTech Connect

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.

Crotts, Arlin P. S. [Department of Astronomy, Columbia University, Columbia Astrophysics Laboratory, 550 West 120th Street, New York, NY 10027 (United States)

2009-05-20

84

Meteorological phenomena in Western classical orchestral music  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

85

Atmospheric anomalies in summer 1908: Water in the atmosphere  

Microsoft Academic Search

A gigantic noctilucent cloud field was formed and different solar halos were observed after the Tunguska catastrophe. To explain these anomalous phenomena, it is necessary to assume that a large quantity of water was carried into the atmosphere, which indicates that the Tunguska cosmic body was of a comet origin. According to rough estimates, the quantity of water that is

O. G. Gladysheva

2011-01-01

86

Astronomy and Atmospheric Optics  

NASA Astrophysics Data System (ADS)

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.

Cowley, Les; Gaina, Alex

2011-12-01

87

Jovian atmospheres  

SciTech Connect

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.

Allison, M.; Travis, L.D.

1986-10-01

88

Transport phenomena in porous media  

NASA Astrophysics Data System (ADS)

The Advanced Study Institute on Fundamentals of Transport Phenomena in Porous Media, held July 14-23, 1985 in Newark, Del. and directed by Jacob Bear (Israel Institute of Technology, Haifa) and M. Yavuz Corapcioglu (City College of New York), under the auspices of NATO, was a sequel to the NATO Advanced Study Institute (ASI) held in 1982 (proceedings published as Fundamentals of Transport Phenomena in Porous Media, J. Bear, and M.Y. Corapcioglu (Ed.), Martinus Nijhoff, Dordrecht, the Netherlands, 1984). The meeting was attended by 106 participants and lecturers from 21 countries.As in the first NATO/ASI, the objective of this meeting—which was a combination of a conference of experts and a teaching institute— was to present and discuss selected topics of transport in porous media. In selecting topics and lecturers, an attempt was made to bridge the gap that sometimes exists between research and practice. An effort was also made to demonstrate the unified approach to the transport of mass of a fluid phase, components of a fluid phase, momentum, and heat in a porous medium domain. The void space may be occupied by a single fluid phase or by a number of such phases; each fluid may constitute a multicomponent system; the solid matrix may be deformable; and the whole process of transport in the system may take place under nonisothermal conditions, with or without phase changes. Such phenomena are encountered in a variety of disciplines, e.g., petroleum engineering, civil engineering (in connection with groundwater flow and contamination), soil mechanics, and chemical engineering. One of the goals of the 1985 NATO/ASI, as in the 1982 institute, was to bring together experts from all these disciplines and enhance communication among them.

Bear, Jacob; Corapcioglu, M. Yavuz

89

Irradiation-induced phenomena in carbon  

E-print Network

Chapter 1 Irradiation-induced phenomena in carbon nanotubes To appear in "Chemistry of Carbon@acclab.helsinki.fi 1 #12;2CHAPTER 1. IRRADIATION-INDUCED PHENOMENA IN CARBON NANOTUBES #12;Contents 1 Irradiation-induced phenomena in carbon nanotubes 1 1.1 Introduction

Krasheninnikov, Arkady V.

90

Natural phenomena hazards, Hanford Site, Washington  

SciTech Connect

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.

Conrads, T.J.

1998-09-29

91

Phenomena and Diosignes of Aratous  

NASA Astrophysics Data System (ADS)

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)

Avgoloupis, S. I.

2013-01-01

92

Gravitational anomaly and transport phenomena.  

PubMed

Quantum anomalies give rise to new transport phenomena. In particular, a magnetic field can induce an anomalous current via the chiral magnetic effect and a vortex in the relativistic fluid can also induce a current via the chiral vortical effect. The related transport coefficients can be calculated via Kubo formulas. We evaluate the Kubo formula for the anomalous vortical conductivity at weak coupling and show that it receives contributions proportional to the gravitational anomaly coefficient. The gravitational anomaly gives rise to an anomalous vortical effect even for an uncharged fluid. PMID:21797593

Landsteiner, Karl; Megías, Eugenio; Pena-Benitez, Francisco

2011-07-01

93

Measurements design and phenomena discrimination  

E-print Network

The construction of measurements suitable for discriminating signal components produced by phenomena of different types is considered. The required measurements should be capable of cancelling out those signal components which are to be ignored when focusing on a phenomenon of interest. Under the hypothesis that the subspaces hosting the signal components produced by each phenomenon are complementary, their discrimination is accomplished by measurements giving rise to the appropriate oblique projector operator. The subspace onto which the operator should project is selected by nonlinear techniques in line with adaptive pursuit strategies.

Laura Rebollo-Neira

2009-08-05

94

Measurements of Atmospheric Electricity Aloft  

NASA Astrophysics Data System (ADS)

Measurements of the electrical characteristics of the atmosphere above the surface have been made for over 200 years, from a variety of different platforms, including kites, balloons, rockets and aircraft. From these measurements, a great deal of information about the electrical characteristics of the atmosphere has been gained, assisting our understanding of the global atmospheric electric circuit, thunderstorm electrification and lightning generation mechanisms, discovery of transient luminous events above thunderstorms and many other electrical phenomena. This paper surveys the history of atmospheric electrical measurements aloft, from the earliest manned balloon ascents to current day observations with free balloons and aircraft. Measurements of atmospheric electrical parameters in a range of meteorological conditions are described, including clear air conditions, polluted conditions, non-thunderstorm clouds, and thunderstorm clouds, spanning a range of atmospheric conditions, from fair weather to the most electrically active.

Nicoll, K. A.

2012-09-01

95

Undergraduate Atmospheric  

E-print Network

-Exploration Planetary Science-Observation Minor Programs Earth, Atmospheric, and Planetary Sciences AstronomyUndergraduate Handbook Earth, Atmospheric and Planetary Sciences #12;EAPS Undergraduate Program, atmospheric science, oceanography, climate, planetary science, and astronomy. The Department's flexible

Rothman, Daniel

96

Sea-surface signatures of the island mass effect phenomena around Madeira Island, Northeast Atlantic  

Microsoft Academic Search

This is an introductory work that describes the manifestation of the island mass effect phenomena in the atmosphere and at the sea surface for a region of the ocean depleted from oceanographic work—the Madeira Archipelago (33°N, 17°W). The use of remote sensing tools becomes essential in recognizing some of the sea-surface features that characterize the island mass effect phenomena. AVHRR,

R. M. A. Caldeira; S. Groom; P. Miller; D. Pilgrim; N. P. Nezlin

2002-01-01

97

Uranium Pyrophoricity Phenomena and Prediction  

SciTech Connect

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.

DUNCAN, D.R.

2000-04-20

98

Atmospheric propagation effects relevant to optical communications  

NASA Technical Reports Server (NTRS)

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.

Shaik, K. S.

1988-01-01

99

Atmospheric Propagation Effects Relevant to Optical Communications  

NASA Technical Reports Server (NTRS)

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.

Shaik, K. S.

1988-01-01

100

New atmospheric sensor analysis study  

NASA Technical Reports Server (NTRS)

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.

Parker, K. G.

1989-01-01

101

Ultraviolet observations of astronomical phenomena  

NASA Technical Reports Server (NTRS)

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).

Mullan, D. J.

1986-01-01

102

48 Optical Illusions & Visual Phenomena  

NSDL National Science Digital Library

Have you ever wondered how different optical illusions work? This fun, informative, and very cool website developed by ophthalmologist Dr. Michael Bach of the University of Freiburg's Medical School introduces 48 interactive visual illusions and phenomena. The illusions are animated and accompanied by explanations that help visitors make sense of their perceptual responses. Major illusion categories include: Motion & Time, Luminance & Contrast, Colour, Cognitive, and more. The site is still in progress, and Dr. Bach encourages both general feedback, and additional scientific information for improving the illusion explanations. The second site, also from Professor Bach, presents site users with an interactive, online Visual Acuity Test. Note: The Contrast component of the Test has yet to be implemented.

103

Weak Values are Interference Phenomena  

E-print Network

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.

Justin Dressel

2015-02-26

104

The quest for new phenomena  

SciTech Connect

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.

Hinchliffe, I.

1996-12-01

105

Relaxation phenomena in cryogenic electrolytes  

NASA Astrophysics Data System (ADS)

Proposed is a scenario for the development of observed relaxation phenomena in a cryogenic electrolyte with the structure of "liquid hydrogen + injected ions." Ions of one sign are generated in the bulk of liquid hydrogen in the presence of external field E? by a stationary radioactive source of ± ions at the bottom of a vessel. After accumulation near the free surface of the liquid with a finite density ns the ions can break its stability producing a pulse of ion current to the collector located above the liquid surface. The outlined process is periodically repeated. Its period contains information on the ion mobility and, which is most interesting, on dissociation (association) processes occurring in a system of charged particles placed in an external field. The cryogenic problem is a good model for dissociation in the presence of external field occurring in normal electrolytes without any external ion sources.

Shikin, V.; Chikina, I.; Nazin, S.

2013-06-01

106

Weak values as interference phenomena  

NASA Astrophysics Data System (ADS)

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.

Dressel, Justin

2015-03-01

107

Unidentified phenomena - Unusual plasma behavior?  

NASA Astrophysics Data System (ADS)

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.

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

1992-06-01

108

Emergent Phenomena at Oxide Interfaces  

SciTech Connect

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.

Hwang, H.Y.

2012-02-16

109

Nanoscale Phenomena in Oxide Heterostructures  

NASA Astrophysics Data System (ADS)

Recent advances in creating complex oxide heterostructures, interfaces formed between two different transition-metal oxides, have heralded a new era of materials and physics research, enabling a uniquely diverse set of coexisting physical properties to be combined with an ever-increasing degree of experimental control. These systems have exhibited varied phenomena such as superconductivity, magnetism, and ferroelasticity, all of which are gate tunable, demonstrating their promise for fundamental discovery and technological innovation. To fully exploit this richness, it is necessary to understand and control the physics on the smallest scales, making the use of nanoscale probes essential. Using the prototypical LaAlO3/SrTiO3 interface as a guide, we explore the exciting developments in the physics of oxide-based heterostructures, with a focus on nanostructures and the nanoscale probes employed to unravel their complex behavior.

Sulpizio, Joseph A.; Ilani, Shahal; Irvin, Patrick; Levy, Jeremy

2014-07-01

110

Solar Irradiance of the Earth's Atmosphere Sultana N. Nahar  

E-print Network

Solar Irradiance of the Earth's Atmosphere Sultana N. Nahar Department of Astronomy, The Ohio State of terrestrial atmospheric phenomena and energy source for the earth. It emits radiation over a large energy band and radiation fluxes. Variations in these emissions interact with all atmospheric layers down to the earth

Nahar, Sultana Nurun

111

Data acquisition and simulation of natural phenomena  

Microsoft Academic Search

Virtual natural phenomena obtained through mathematical-physical modeling and simulation as well as graphics emulation can\\u000a meet the user’s requirements for sensory experiences to a certain extent but they can hardly have the same accurate physical\\u000a consistency as real natural phenomena. The technology for data acquisition and natural phenomena simulation can enable us\\u000a to obtain multi-dimensional and multi-modal data directly from

QinPing Zhao

2011-01-01

112

Intrinsic interfacial phenomena in manganite heterostructures  

NASA Astrophysics Data System (ADS)

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

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

2015-04-01

113

Intrinsic interfacial phenomena in manganite heterostructures.  

PubMed

We review recent advances in our understanding of interfacial phenomena that emerge when dissimilar materials are brought together at atomically sharp and coherent interfaces. In particular, we focus on phenomena that are intrinsic to the interface and review recent work carried out on perovskite manganites interfaces, a class of complex oxides whose rich electronic properties have proven to be a useful playground for the discovery and prediction of novel phenomena. PMID:25721578

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

2015-04-01

114

Ordering Phenomena in Undercooled Alloys  

SciTech Connect

Much of the work performed under this grant was devoted to using modern ideas in kinetics to understand atom movements in metallic alloys far from thermodynamic equilibrium. Kinetics arguments were based explicitly on the vacancy mechanism for atom movements. The emphasis was on how individual atom movements are influenced by the local chemical environment of the moving atom, and how atom movements cause changes in the local chemical environments. The author formulated a kinetic master equation method to treat atom movements on a crystal lattice with a vacancy mechanism. Some of these analyses [3,10,16] are as detailed as any treatment of the statistical kinetics of atom movements in crystalline alloys. Three results came from this work. Chronologically they were (1) A recognition that tracking time dependencies is not necessarily the best way to study kinetic phenomena. If multiple order parameters can be measured in a material, the ''kinetic path'' through the space spanned by these order parameters maybe just as informative about the chemical factors that affect atom movements [2,3,5-7,9-11,14-16,18,19,21,23,24,26,36,37]. (2) Kinetic paths need not follow the steepest gradient of the free energy function (this should be well-known), and for alloys far from equilibrium the free energy function can be almost useless in describing kinetic behavior. This is why the third result surprised me. (3) In cluster approximations with multiple order parameters, saddle points are common features of free energy functions. Interestingly, kinetic processes stall or change time scale when the kinetic path approaches a state at a saddle point in the free energy function, even though these states exist far from thermodynamic equilibrium. The author calls such a state a ''pseudostable'' (falsely stable) state [6,21,26]. I have also studied these phenomena by more ''exact'' Monte Carlo simulations. The kinetic paths showed features similar to those found in analytical theories. The author found that a microstructure with interfaces arranged in space as a periodic minimal surface is a probably an alloy at a saddle point in its free energy function [21,26,37].

Fultz, Brent

1997-07-17

115

Observation of Celestial Phenomena in Ancient China  

NASA Astrophysics Data System (ADS)

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.

Sun, Xiaochun

116

Macroscopic Modeling of Transport Phenomena in  

E-print Network

Technology Pontoppidanstræde 101 9220 Aalborg Denmark #12;Title: Macroscopic Modeling of Transport Phenomena applica- tions. This type of fuel cell directly generates electricity from a fuel mixture consisting

Berning, Torsten

117

Modeling Defect-Induced Phenomena  

NASA Astrophysics Data System (ADS)

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

Kuklja, Maija M.; Rashkeev, Sergey N.

118

Precursor films in wetting phenomena.  

PubMed

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

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

2012-06-20

119

Precursor films in wetting phenomena  

NASA Astrophysics Data System (ADS)

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

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

2012-06-01

120

WESF natural phenomena hazards survey  

SciTech Connect

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.

Wagenblast, G.R., Westinghouse Hanford

1996-07-01

121

Review - Axial compressor stall phenomena  

NASA Technical Reports Server (NTRS)

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

Greitzer, E. M.

1980-01-01

122

Monitoring of Transient Lunar Phenomena  

NASA Astrophysics Data System (ADS)

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

Barker, Timothy; Farber, Ryan; Ahrendts, Gary

2014-06-01

123

Understanding Atmospheric Catastrophes  

NASA Technical Reports Server (NTRS)

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.

Chao, Winston C.

2009-01-01

124

Unsteady flow phenomena in industrial centrifugal compressor stage  

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

125

Atmosphere control  

NASA Technical Reports Server (NTRS)

Atmospheric control studies emphasized the carbon dioxide problem. Trace contaminants are removed by solid adsorbents and by catalytic oxidation. Humidity control and storage systems for atmospheric constituents are briefly summarized.

Jones, W. L.; Ingelfinger, A. L.

1973-01-01

126

Analysis of atmospheric delays and asymmetric positioning errors in the global positioning system  

E-print Network

Abstract Errors in modeling atmospheric delays are one of the limiting factors in the accuracy of GPS position determination. In regions with uneven topography, atmospheric delay phenomena can be especially complicated. ...

Materna, Kathryn

2014-01-01

127

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

SciTech Connect

'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.

Morfill, Gregor E.; Ivlev, Alexei V.; Thomas, Hubertus M. [Max-Planck-Institut fuer Extraterrestrische Physik, D-85740 Garching (Germany)

2012-05-15

128

Modelling of Transient Phenomena in Gas Discharges  

E-print Network

Modelling of Transient Phenomena in Gas Discharges Wouter Brok #12;Copyright 2005 by W.J.M. Brok Johannes Maria Modelling of transient phenomena in gas discharges / by Woutherus Johannes Maria Brok Subject headings : plasma physics / gas discharges / light sources / Monte Carlo methods / fluid models

Eindhoven, Technische Universiteit

129

Repetitive speech phenomena in Parkinson's disease  

Microsoft Academic Search

OBJECTIVESRepetitive speech phenomena are morphologically heterogeneous iterations of speech which have been described in several neurological disorders such as vascular dementia, progressive supranuclear palsy, Wilson's disease, and Parkinson's disease, and which are presently only poorly understood. The present, prospective study investigated repetitive speech phenomena in Parkinson's disease to describe their morphology, assess their prevalence, and to establish their relation with

Th Benke; C Hohenstein; W Poewe; B Butterworth

2000-01-01

130

Convective storms in planetary atmospheres  

NASA Astrophysics Data System (ADS)

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

Hueso, R.; Sánchez-Lavega, A.

2013-05-01

131

Interactive atmosphere  

NSDL National Science Digital Library

Where is ozone located in the atmosphere? This informational activity, part of an interactive laboratory series for grades 8-12, explores the changes in ozone concentration with altitude. Students are introduced to layers of the atmosphere and the amount of ozone found at each layer of the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. The activity also discusses why the addition of ozone to the atmosphere at different levels determines the temperatures of those levels. Students can move up and down to different layers of the atmosphere. A temperature scale is shown that runs from the surface of the Earth to the outer most reaches of the atmosphere. Copyright 2005 Eisenhower National Clearinghouse

University of Utah. Astrophysics Science Project Integrating Research and Education (ASPIRE)

2003-01-01

132

Atmospheric gases  

NSDL National Science Digital Library

Which gases make up the atmosphere? This activity page, part of an interactive laboratory series for grades 8-12, introduces students to the gaseous components of the atmosphere. Students explore the main gases of the atmosphere using a pop-up pie chart. Descriptions of the gases and their percentages in the atmosphere are provided. Students read about water vapor in the atmosphere, and an animation shows a simplified process of precipitation. A pop-up window explains the effects of dust on the atmosphere, and a photograph shows how large amounts of dust in the atmosphere create the reds and oranges displayed in sunsets. Finally, ozone is introduced to students as a necessary component of human life on Earth. Copyright 2005 Eisenhower National Clearinghouse

University of Utah. Astrophysics Science Project Integrating Research and Education (ASPIRE)

2003-01-01

133

NASA/MSFC FY-81 Atmospheric Processes Research Review  

NASA Technical Reports Server (NTRS)

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.

Turner, R. E. (compiler)

1981-01-01

134

The Seismoacoustic Wavefield: A New Paradigm in Studying Geophysical Phenomena  

NASA Astrophysics Data System (ADS)

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.

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

2010-12-01

135

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

NASA Technical Reports Server (NTRS)

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.

Klimchuk, James

2010-01-01

136

Atmospheric emissions photometric imaging experiment  

NASA Technical Reports Server (NTRS)

The atmospheric emissions photometric imaging experiment was flown on Spacelab 1 to study faint natural and artificial atmospheric emission phenomena. The instrument imaged optical emission in the region 2000 to 7500 angstroms with a television system consisting of two optical channels, one wide-angle and one telephoto. A third optical channel imaged onto the photocathode of a microchannel plate photomultiplier tube that has 100 discrete anodes. A hand-held image intensifier camera with an objective grating permitted spectral analysis of the earth's airglow and the Shuttle glow. Preliminary data show magnesium ion emission features in the lower ionosphere as well as the spacecraft glow spectrum.

Mende, S. B.; Swenson, G. R.; Clifton, K. S.

1984-01-01

137

Atmospheric effects on laser propagation  

SciTech Connect

The linearized theory of thermal blooming instabilities is reviewed. The dispersion relation is derived for unstable modes with and without correction. Perfect phase-only correction is unstable at all spatial scales, while perfect field conjugation is stable at all scales. Various atmospheric phenomena such as turbulence, diffusion and wind shear may mitigate or dampen the instabilities. Full nonlinear time-dependent computer simulations of laser atmospheric propagation agree with the dispersion relation for small perturbations, and show saturation and nonlinear mode beating at long times. 2 refs., 7 figs.

Karr, T.J. (Lawrence Livermore National Lab., CA (USA))

1989-03-16

138

Atmospheric effects on laser propagation  

SciTech Connect

The linearized theory of thermal blooming instabilities is reviewed. The dispersion relation is derived for unstable modes with and without correction. Perfect phase-only correction is unstable at all spatial scales, while perfect field conjugation is stable at all scales. Various atmospheric phenomena, such as turbulence, diffusion and wind shear may mitigate or dampen the instabilities. Full nonlinear time-dependent computer simulations of laser atmospheric propagation agree with the dispersion relation for small perturbations, and show saturation and nonlinear mode beating at long times. 2 refs., 7 figs.

Karr, T.J.

1988-11-22

139

Infrared experiments for spaceborne planetary atmospheres research. Full report  

NASA Technical Reports Server (NTRS)

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.

1981-01-01

140

S-290 Unit 6: Atmospheric Stability  

NSDL National Science Digital Library

S-290 Unit 6: Atmospheric Stability introduces the processes related to stable and unstable atmospheric conditions and explains their impact on fire behavior. This Unit provides detailed information about how fire behavior is affected by stable and unstable atmospheric phenomena such as inversions and thunderstorms. The Unit also explains cloud formation and describes the usage of clouds and other visual indicators to recognize stable and unstable atmospheric conditions. The module is part of the Intermediate Wildland Fire Behavior Course "http://www.meted.ucar.edu/dl_courses/S290".

COMET

2010-03-02

141

Carbon dioxide opacity of the Venus' atmosphere  

NASA Astrophysics Data System (ADS)

Venus' atmosphere consists of about 95% of carbon dioxide, which accounts for most of the absorption of the radiation emitted by its hot surface. The large densities and high temperatures of Venus' atmosphere make the absorption much more complex than for low density atmospheres such as Earth or Mars. Available experimental data are at present insufficient and theoretical models inadequate to describe complex absorption line shapes and collision-induced phenomena. Here we present a survey of all absorption and scattering processes which influence the transparency of Venus' atmosphere for what concerns carbon dioxide.

Snels, Marcel; Stefani, Stefania; Grassi, Davide; Piccioni, Giuseppe; Adriani, Alberto

2014-11-01

142

Mathematics needed for Introduction to Transport Phenomena  

NSDL National Science Digital Library

A collection of math problems based on skills needed to successfully complete homework problems in an introductory course in Transport Phenomena. These problems do not introduce any new material for those who have taken Freshman Calculus classes and a sophomore level Differential Equations class. At Purdue University in the required Transport Phenomena course for MSE undergrads (MSE 340), I give a problem set like this the first day of classes in order to make clear the level of mathematical skill needed for the rest of the semester. I have found that it reduces difficulties with math later in the semester, allowing the students to focus on the transport phenomena.

Krane, Matthew J. M.

2007-10-12

143

Atmospheric dust  

NSDL National Science Digital Library

What is the purpose of dust in the atmosphere? On this activity page, part of an interactive laboratory series for grades 8-12, students read about the need for dust in the atmosphere as an agent for condensation. The addition of dust particles to the atmosphere by airplanes introduces students to the concept of cloud seeding and influencing the chance of rain in an area. Copyright 2005 Eisenhower National Clearinghouse

University of Utah. Astrophysics Science Project Integrating Research and Education (ASPIRE)

2003-01-01

144

Atmospheric neutrons  

NASA Technical Reports Server (NTRS)

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.

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

1979-01-01

145

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

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

146

A technique for creating new visual phenomena  

E-print Network

This paper outlines a technique for creating new visual phenomena by proposing a systematic method of using existing media in novel manners. The technique involve s the random and purposeful manipulation of person-media ...

Ritter, Donald

1988-01-01

147

Canister storage building natural phenomena design loads  

SciTech Connect

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.

Tallman, A.M.

1996-02-01

148

Bayesian nonparametric learning of complex dynamical phenomena  

E-print Network

The complexity of many dynamical phenomena precludes the use of linear models for which exact analytic techniques are available. However, inference on standard nonlinear models quickly becomes intractable. In some cases, ...

Fox, Emily Beth

2009-01-01

149

Reproductive phenomena of a sexual buffelgrass plant  

E-print Network

REPRODUCTIVE PHENOMENA OF A SEXUAL EUFFELGRASS PLANT A Thesis 3y Charles Millard Taliaferro . Submitted to the Graduate School of the A & M University of Texas in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... January 1964 Major Sub?'ect Agronomy REPRODUCTIVE PHENOMENA OF A SEXUAL BUFFELGRASS PLANT A Thesis Charles Millard Taliaferro Approved as to style and content by: (Chairman of Committee) (Head of Department) / ember) (Member) Memb er) January...

Taliaferro, Charles Millard

1965-01-01

150

The Atmosphere.  

ERIC Educational Resources Information Center

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)

Ingersoll, Andrew P.

1983-01-01

151

Atmospheric electricity  

Microsoft Academic Search

Owing to the somewhat explosive development of the science of atmospheric electricity during the past decade this article covers a broad field of activity. The article begins with a description and discussion of the work that has been performed to understand the electrical properties of the basic materials involved in generating processes in the atmosphere, namely ice, water, and sand

C D Stow

1969-01-01

152

Atmospheric Environment ] (  

E-print Network

of neutrally stratified atmospheric boundary layers over heterogeneous terrain. Water Resources Research 42, W (Atmospheric Environment Service, Canada) [Gong, W., Taylor, P.A., Do¨ rnbrack, A., 1996. Turbulent boundary-layer boundary-layer flow over a rough two-dimensional sinusoidal hill. Three different subgrid-scale (SGS

Stoll, Rob

153

Atmospheric chemistry  

SciTech Connect

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.

Sloane, C.S. (General Motors Research Labs., Warren, MI (United States)); Tesche, T.W. (Alpine Geophysics (US))

1991-01-01

154

Atmospheric ozone  

NASA Astrophysics Data System (ADS)

The book contains papers given during the All-Union Atmospheric Ozone Conference (Suzdal', October 1988). Papers are presented on the instruments and methodology for measuring atmospheric ozone; results of measurements of ozone, other atmospheric gases, and aerosol; measurements of ozone and of trace gases in the Antarctic; the chemistry and the radiation regime in the ozonosphere; and modeling the ozonosphere. Particular attention is given to reactions between ozone and heterogeneous components of the atmosphere and to changes in tropospheric ozone. It is shown that periods of seismic activity (in particular, earthquakes with values of M not less than 3.5) coincide with short-term (1-2-days long) increases in the atmospheric ozone content.

Kokin, G. A.

155

Atmospheric science encompasses meteorology and climatology, as well as fields such as atmospheric chemistry and remote sensing.Atmospheric  

E-print Network

the atmosphere well enough to make accurate predictions of important phenomena, such as weather, climate to study storm systems and severe weather is the Houston-area lightning network maintained by faculty the undergraduate course of study receive a Bachelor of Science degree in Meteorology.The B.S. in Meteorology

156

Solar Neutrons and Related Phenomena  

NASA Astrophysics Data System (ADS)

EAndersNGrevesse1989Abundances of the elements: meteoritic and solarGeochim Cosmochim Acta (UK)5311972141989GeCoA..53..197A10.1016/0016-7037(89)90286-XAnders E, Grevesse N (1989) Abundances of the elements: meteoritic and solar. Geochim Cosmochim Acta (UK) 53(1):197-214 Aschwanden MJ, Wills MJ, Hudson HS, Kosugi T, Schwartz RA (1996) Electron time-of-flight distances and flare loop geometries compared from CGRO and Yohkoh observations. Astrophys J (USA) 468(1, Part 1):398-417 EAslanidesPFassnachtGDellacasaMGallioJWNTuyn198112C(3He, 3He n)11C cross section at 910 MeVPhys Rev C Nucl Phys (USA)234182618281981PhRvC..23.1826A10.1103/PhysRevC.23.1826Aslanides E, Fassnacht P, Dellacasa G, Gallio M, Tuyn JWN (1981) 12C(3He, 3He n)11C cross section at 910 MeV. Phys Rev C Nucl Phys (USA) 23(4):1826-1828 Avrett EH (1981) Reference model atmosphere calculation - the Sunspot sunspot model. In: Cram LE, Thomas JH (eds) The physics of sunspots, Proceedings of the conference, Sunspot, New Mexico, 1981, conference sponsored by the Sacramento Peak Observatory, Sunspot, NM, pp 235-255, 257 Brekke P, Rottman GJ, Fontenla J, Judge PG (1996) The ultraviolet spectrum of a 3B class flare observed with SOLSTICE. Astrophys J (USA) 468(1, Part 1):418-432 ODBrill1965He3-light nucleus interaction cross sectionsSoviet J Nu

Dorman, Lev I.

157

The atmospheres of M dwarfs: Observations  

NASA Technical Reports Server (NTRS)

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.

Rodono, Marcello

1987-01-01

158

Extremes and Atmospheric Data Eric Gilleland  

E-print Network

for Atmospheric Research 2007-08 Program on Risk Analysis, Extreme Events and Decision Theory, opening workshop 16-19 September, North Carolina #12;Extremes · Interest in making inferences about large, rare, extreme phenomena sensing (e.g., satellite) ­ Model Output (e.g., Weather/Climate models) #12;Software · R: ­ statistical

Gilleland, Eric

159

Anomalous Light Phenomena vs. Bioelectric Brain Activity  

NASA Astrophysics Data System (ADS)

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.

Teodorani, M.; Nobili, G.

160

Thermodynamics and Transport Phenomena in High Temperature Steam Electrolysis Cells  

SciTech Connect

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.

James E. O'Brien

2012-03-01

161

Atmospheric tritium  

SciTech Connect

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)

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

1980-01-01

162

Exoplanet Atmospheres  

E-print Network

At the dawn of the first discovery of exoplanets orbiting Sun-like stars in the mid-1990s, few believed that observations of exoplanet atmospheres would ever be possible. After the 2002 Hubble Space Telescope detection of ...

Seager, Sara

163

Earth's Atmosphere  

NSDL National Science Digital Library

This problem set is about the methods scientists use to compare the abundance of the different elements in Earth's atmosphere. Answer key is provided. This is part of Earth Math: A Brief Mathematical Guide to Earth Science and Climate Change.

2012-08-03

164

Atmospheric Environment ] (  

E-print Network

Elsevier Ltd. All rights reserved. Keywords: 3-D CTM; Tropospheric ozone; Air quality; Ozone precursors 1 or hemispheric ozone background as an external influence on Europe's air quality in the light of the continuingAtmospheric Environment ] (

165

Corona in atmospheric air between negative point and plane electrodes  

Microsoft Academic Search

The phenomena of corona between negative point and plane electrodes in atmospheric air have been found to consist of Trichel pulses above onset. Results of experimental investigations on negative point plane corona in air at atmospheric pressure for DC voltage applications are reported in this paper. The diameter of the hemispherical tip used in these investigations varied from 1.0 mm

G. R. Gurumurthy; J. Amarnath; B. R. Natarajan

2004-01-01

166

Atmospheric Dust  

NSDL National Science Digital Library

Millions of tons of dust are lifted from deserts annually, suspended in the atmosphere, and released to fall on the oceans, but scientists are a long way from understanding the impact of atmospheric dust on the climate and weather systems of Earth or on marine organisms. This radio broadcast explains how the nitrogen, phosphorus and iron released from dust boosts the growth of phytoplankton, which also soak up carbon dioxide and release more gases into the atmosphere. Better monitoring and more sophisticated sensors are giving us a more accurate picture of the dust in the atmosphere; the broadcast reports on investigations of dust from ice cores and on computer simulations of the connections between dust and climate. But the unpredictable nature of dust events makes it extremely difficult to determine their impact on the natural systems of Earth. There are discussions with geographers, oceanographers, environmentalists and climate modelers about atmospheric dust, one of the least understood and most contradictory components of the atmosphere. The broadcast is 28 minutes in length.

167

Theories of dynamical phenomena in sunspots  

NASA Technical Reports Server (NTRS)

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

Thomas, J. H.

1981-01-01

168

The making of extraordinary psychological phenomena.  

PubMed

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

Lamont, Peter

2012-01-01

169

Static Friction Phenomena The following static friction phenomena have a direct dependency on velocity.  

E-print Network

Coulomb Friction Viscous Friction Stribeck Friction Static Friction Phenomena The following static friction phenomena have a direct dependency on velocity. Static Friction Model: Friction force opposes the direction of motion when the sliding velocity is zero. Coulomb Friction Model: Friction force

Simpkins, Alex

170

Abnormal mental phenomena in the prophets.  

PubMed

Abnormal mental phenomena of varying emotional depth are found frequently among the earlier, nonliterary, and literary prophets. Three levels are discerned: inspiration, i.e., a state of excitement with well-preserved reality controls; ecestasy, as a state in which reality control has been lost temporarily; and eidetic imagery characterized by dreams and visions. It is argued that the prophets were psychotics, or mystics, or poets, or endowed with psychic gifts. I have attempted to consider some of these phenomena from the psychiatric viewpoint, keeping in mind that such interpretations many centuries later must remain speculative. PMID:24408495

Nussbaum, K

1974-07-01

171

Fundamental investigation of duct/ESP phenomena  

SciTech Connect

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)

Brown, C.A. (Radian Corp., Austin, TX (United States)); Durham, M.D. (ADA Technologies, Inc., Englewood, CO (United States)); Sowa, W.A. (California Univ., Irvine, CA (United States). Combustion Lab.); Himes, R.M. (Fossil Energy Research Corp., Laguna Hills, CA (United States)); Mahaffey, W.A. (CHAM of North America, Inc., Huntsville, AL (United States))

1991-10-21

172

Incorporating interfacial phenomena in solidification models  

NASA Technical Reports Server (NTRS)

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.

Beckermann, Christoph; Wang, Chao Yang

1994-01-01

173

Modeling of fundamental phenomena in welds  

SciTech Connect

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.

Zacharia, T.; Vitek, J.M. [Oak Ridge National Lab., TN (United States); Goldak, J.A. [Carleton Univ., Ottawa, Ontario (Canada); DebRoy, T.A. [Pennsylvania State Univ., University Park, PA (United States); Rappaz, M. [Ecole Polytechnique Federale de Lausanne (Switzerland); Bhadeshia, H.K.D.H. [Cambridge Univ. (United Kingdom)

1993-12-31

174

High-energy photons connected to atmospheric precipitations  

NASA Astrophysics Data System (ADS)

Increases in intensity of X-radiation in the ground layer of the atmosphere observed during various atmospheric phenomena in two points: Apatity (Kola Peninsula) and Barentsburg (Spitsbergen) have been studied. A clear relationship between the increases and such atmospheric phenomena as rain and snowfall has been found. It is shown that these increases are not connected with any radionuclides. This research suggests that the principal cause of high-energy photons increase during precipitations are bremsstrahlung X-rays created by energetic electrons accelerated by electric fields in the clouds. A possible mechanism of generation of X-ray photons is discussed.

Germanenko, A. V.; Balabin, Yu. V.; Vashenyuk, E. V.; Gvozdevsky, B. B.; Schur, L. I.

2011-10-01

175

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...

176

Corporate strategy and the Social Networking phenomena  

Microsoft Academic Search

The Social Networking (SN) phenomena has developed relatively overnight and is continuing to develop at an exponential pace. It allows for innovative new methods of disseminating and collecting information in ways never before dreamed possible by corporate executives. The rise of Social Networking is becoming a disruptive technology for traditional marketing and advertising medium such as radio, television, web page,

Robert L. Johnson

2010-01-01

177

Quantization makes Relativity Compatible with Superluminal Phenomena  

E-print Network

By relativity we show that, although the superluminal motion of classical particles is forbidden, the superluminal transportation of quanta of any massive matter field is possible. Exact theoretical derivation and precise numerical computation are presented. To search the superluminal phenomena is therefore still meaningful.

Qi-Ren Zhang

2012-03-08

178

Sonoluminescence and other energy focusing phenomena  

Microsoft Academic Search

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

Seth Putterman

2005-01-01

179

Animal models of speech perception phenomena  

Microsoft Academic Search

Science, by tradition and foundational philosophy, is conservative. General theories that are broad in app lication and austere in constructs and variables are preferred to proliferation of specific explanations for individual phenomena. When general, simple accounts no longer suffice as explanations of the available data, novel constructs and theories become necessary. Fifty years ago, speech perception was considered to be

Andrew J. Lotto; Keith R. Kluender; Lori L. Holt

180

Gods, Heroes and Natural Phenomena Cosmologies  

Microsoft Academic Search

People have always been worried about the natural phenomena that have influenced their lives and the origin of these natural changes. That is why they have always tried to explain the creation of the world probably as a way to control it, protect them from it, or simply to understand it. It is always relevant to humankind to try to

Miguel Angel Alarcón

181

Photo-Galvano-Mechanical Phenomena in Nanotubes  

E-print Network

Photo-Galvano-Mechanical Phenomena in Nanotubes Petr KraI\\ E. J. Mele2 , David Tomanek3 and Moshe present new effects in nanotubes, as induced by light and friction with fluids. First, we show that atoms intercalated in C nanotubes can be driven by a dc electric current, generated optically by mixing one and two

182

Thermoelectric phenomena via an interacting particle system  

E-print Network

Thermoelectric phenomena via an interacting particle system Christian Maes and Maarten H. van transport in different but connected metallic substances. The electrons hop between energy-cells located alongside the spatial extension of the metal wire. When changing energy level, the system exchanges energy

Maes, Christian

183

Thermoelectric phenomena via an interacting particle system  

E-print Network

Thermoelectric phenomena via an interacting particle system Christian Maes and Maarten H. van transport in di#erent but connected metallic substances. The electrons hop between energy­cells located alongside the spatial extension of the metal wire. When changing energy level, the system exchanges energy

Maes, Christian

184

Superconductivity and other macroscopic quantum phenomena  

Microsoft Academic Search

A diverse class of macroscopic quantum phenomena including superconductors, superfluid helium, lasers, and quasi-one-dimensional conductors, exhibiting a common feature of macroscopic occupation of a single quantum state, is presented. Some of the features that are considered important in the design of structures of smaller scale are the following: the quantum states of macroscopic bodies are discrete; there can be macroscopic

John Bardeen

1990-01-01

185

Expanding Roles for Diverse Physical Phenomena During  

E-print Network

Expanding Roles for Diverse Physical Phenomena During the Origin of Life Itay Budin and Jack W, protocell Abstract Recent synthetic approaches to understanding the origin of life have yielded insights with implications for the origin of life, emphasizing the ability of unexpected physical processes to facilitate

Heller, Eric

186

Analysis of Electromagnetic Phenomena in HTc Superconductors  

Microsoft Academic Search

Unique electromagnetic properties, especially concerning recent observations of the giant remanent magnetic moment in HTc superconductors, require new approach to modeling these phenomena in the oxide ceramics. The present paper is devoted to the analysis of the influence of flux pinning on critical current and flux trapping in HTc superconductors. Modeling of the interaction between nanosized pinning centers and pancake

J. Sosnowski

2008-01-01

187

Displaying Computer Simulations Of Physical Phenomena  

NASA Technical Reports Server (NTRS)

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.

Watson, Val

1991-01-01

188

Unexplained Spectral Phenomena in the Interstellar Medium  

NASA Astrophysics Data System (ADS)

We present an overview of the present observational status of unexplained spectral phenomena in the ISM. The possibility of organic molecules and solids as the carrier of the DIB, 217 nm feature, ERE, UIR, and the 21 and 30 ?m features is discussed.

Kwok, Sun

2015-03-01

189

Sources of Magnetic Field Magnetic Phenomena  

E-print Network

push on currents Moving charges can make and feel magnetic forces. We don't understand how permanent will consider the last piece of the puzzle in electromagnetic - changing magnetic fields can make induction. 15Lecture 9 Sources of Magnetic Field 1 Magnetic Phenomena 1. Magnets can push on each other (and

Tobar, Michael

190

Time Fractional Formalism: Classical and Quantum Phenomena  

E-print Network

In this review, we present some fundamental classical and quantum phenomena in view of time fractional formalism. Time fractional formalism is a very useful tool in describing systems with memory and delay. We hope that this study can provide a deeper understanding of the physical interpretations of fractional derivative.

Hosein Nasrolahpour

2012-03-18

191

Exploratorium Exhibit and Phenomena Cross Reference  

NSDL National Science Digital Library

This alphabetical list of links explains a variety of scientific phenomena. Clicking on the name of a particular phenomenon will provide the user with a written definition or description and a list of links to exhibits (another part of the site) which illustrate it.

192

Geophysical phenomena classification by artificial neural networks  

NASA Technical Reports Server (NTRS)

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.

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

1995-01-01

193

Geophysical phenomena classification by artificial neural networks  

SciTech Connect

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.

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

1995-01-01

194

Interfacial phenomena and the ocular surface.  

PubMed

Ocular surface disorders, such as dry eye disease, ocular rosacea, and allergic conjunctivitis, are a heterogeneous group of diseases that require an interdisciplinary approach to establish underlying causes and develop effective therapeutic strategies. These diverse disorders share a common thread in that they involve direct changes in ocular surface chemistry as well as the rheological properties of the tear film and topographical attributes of the cellular elements of the ocular surface. Knowledge of these properties is crucial to understand the formation and stability of the preocular tear film. The study of interfacial phenomena of the ocular surface flourished during the 1970s and 1980s, but after a series of lively debates in the literature concerning distinctions between the epithelial and the glandular origin of ocular surface disorders during the 1990s, research into this important topic has declined. In the meantime, new tools and techniques for the characterization and functionalization of biological surfaces have been developed. This review summarizes the available literature regarding the physicochemical attributes of the ocular surface, analyzes the role of interfacial phenomena in the pathobiology of ocular surface disease, identifies critical knowledge gaps concerning interfacial phenomena of the ocular surface, and discusses the opportunities for the exploitation of these phenomena to develop improved therapeutics for the treatment of ocular surface disorders. PMID:24999101

Yañez-Soto, Bernardo; Mannis, Mark J; Schwab, Ivan R; Li, Jennifer Y; Leonard, Brian C; Abbott, Nicholas L; Murphy, Christopher J

2014-07-01

195

Classification of Gas-Dust Structures in the Upper Atmosphere Associated with the Exhausts of Rocket-Engine Combustion Products  

Microsoft Academic Search

This paper presents the results of investigating optical phenomena in the upper atmosphere that accompany rocket launches and are associated with specific features of the structure and dynamics of gas-dust formations in the upper atmosphere. The most intense, large-scale, and dynamic phenomena are induced by specific operation modes of rocket engines, in particular, by the staging and thrust cutoff in

Yu. V. Platov; G. N. Kulikova; S. A. Chernouss

2003-01-01

196

Atmospheric continuum absorption models  

NASA Astrophysics Data System (ADS)

Accurate models are needed to represent both the local lines and the continuum absorption in spectral ranges of interest. Additionally, accurate experimental data are needed, under different conditions of pressure and temperature, to test the validity of various models. Experimental data are obtained from a BOMEM fourier transform spectrometer (FTS) with a high pressure-high temperature cell and a 10-m white cell. Absorption coefficients are determined for gas mixtures (H2O, CO2, N2, O2) for pressure up to 60 atm and temperatures up to 600 K. At high pressure, the Lorentzian approach fails, and semi- empirical models are used to represent local line and far wing phenomena. The far wing nature of the line shape theory of Birnbaum is used to represent the water vapor continuum. Comparisons are made between our experimental data and synthetic spectra based on the HITRAN data base and Birnbaum's line shape for several atmospheric transmission window regions. Implications concerning atmospheric propagation are emphasized.

Delaye, Corinne T.; Thomas, Michael E.

1991-07-01

197

Crystal Melting and Wall Crossing Phenomena  

NASA Astrophysics Data System (ADS)

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.

Yamazaki, Masahito

2010-02-01

198

Seasonal Variability of Saturn's Atmosphere  

NASA Technical Reports Server (NTRS)

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).

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

2012-01-01

199

ATMOSPHERIC ~ ~ RESEARCH  

E-print Network

. 1. Introduction Air pollution and acid rain have become the subject of (not only) scientific within the troposphere and the transport of pollutants as well as acid rain even in rural regions the atmosphere by wet deposition. Moreover, the ambient temperature is influ- enced by the phase transitions

Moelders, Nicole

200

Atmospheric Chemistry  

NSDL National Science Digital Library

This set of links provides access to resources on atmospheric chemistry, especially acid deposition, air pollution, and air quality. The sites include personal and government pages, universities and research groups, non-governmental organizations and meetings, and products and services. There are also links to related search topics.

201

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

PubMed

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

O'brien, B J

1965-04-23

202

Atmospheric anomalies in summer 1908: Water in the atmosphere  

NASA Astrophysics Data System (ADS)

A gigantic noctilucent cloud field was formed and different solar halos were observed after the Tunguska catastrophe. To explain these anomalous phenomena, it is necessary to assume that a large quantity of water was carried into the atmosphere, which indicates that the Tunguska cosmic body was of a comet origin. According to rough estimates, the quantity of water that is released into the atmosphere as a result of a cosmic body's destruction is more than 1010 kg. The observation of a flying object in an area with a radius of ?700 km makes it possible to state that the Tunguska cosmic body looked like a luminous coma with a diameter not smaller than ?10 km and became visible at heights of >500 km. The assumption that the Tunguska cosmic body started disintegrating at a height of ˜1000 km explains the formation of an area where its mater diffused and formed a luminous area above Europe.

Gladysheva, O. G.

2011-10-01

203

A review of impulsive phase phenomena  

NASA Technical Reports Server (NTRS)

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.

Dejager, C.

1986-01-01

204

How Might You Investigate Scientific Phenomena?  

NSDL National Science Digital Library

This site, part of Exploring Earth Investigation by McDougal Littell and TERC, examines how to investigate scientific phenomena. The investigations "were designed to build students' knowledge of Earth Science conceptsâ?¦and to raise student awareness of Earth as a system of interconnected components and processes." Here, visitors will learn about the steps that allow scientists to create valid investigations of phenomena: forming a hypothesis, determining the appropriate method of investigation, collecting and graphing data, and hypothesis testing. Many sections have illustrative images and interactive features which help students understand the topics presented, and the final section ends with questions for students to further explore as well as a link to some NASA datasets. This is an excellent site for any Earth Science classroom as an introductory lecture to the scientific method or as an out-of-class exploration for students.

2008-09-05

205

Transport Phenomena During Equiaxed Solidification of Alloys  

NASA Technical Reports Server (NTRS)

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.

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

1997-01-01

206

Neisseria sicca endocarditis with embolic phenomena.  

PubMed

Two patients with poor oral hygiene developed Neisseria sicca endocarditis, one after probable intravenous drug abuse and Staphylococcus aureus endocarditis and the other after a periodontal surgical procedure. Both experienced significant embolic phenomena and both required 6 or more weeks of intravenous antibiotic therapy. The diagnosis of N. sicca endocarditis must be considered when this organism is isolated from blood cultures in patients with emboli. PMID:1572142

Vernaleo, J R; Mathew, A; Cleri, D J; D'Amato, R F; Joachim, G R; Papa, T M; Mastellone, A J; Wallman, A A; Perlman, J

1992-02-01

207

Quantum statistical theory of optical phenomena  

PubMed Central

The purpose of this paper is to develop a density matrix formulation for optical phenomena that can be applied to both steady and transient states and to both resonance and off-resonance regions. To demonstrate the application, this theory has been applied to the steady-state one-photon and two-photon processes. We have found that, in the resonance region, the conventional equation used is incomplete; other terms that are comparable in importance have been ignored. PMID:16592424

Lin, S. H.; Eyring, H.

1977-01-01

208

Topological phenomena in ultracold atomic gases  

E-print Network

happiness. Most of all, my deepest love and thanks go to my parents and my brother for their constant support and encouragement. iii Summary Topological phenomena arise in a wide range of systems, with fascinating phys- ical consequences. There is great... geometrical properties of topological energy bands. Lastly, we study theoretically the dynamics of two-component Bose-Einstein condensates in two dimensions, which admit topological excitations related to the skyrmions of nuclear physics. We explore a branch...

Price, Hannah

2013-10-08

209

Observations of Cometary Plasma Wave Phenomena  

Microsoft Academic Search

The ICE plasma wave investigation utilized very long electric antennas (90 meters tip-to-tip) and a very high sensitivity magnetic search coil to obtain: (1) significant local information on plasma physics phenomena occurring in the distant pickup regions of comet Giacobini-Zinner and comet P\\/Halley, and (2) information on the processes that developed in the coma and tail of Giacobini-Zinner. Since ICE

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

1987-01-01

210

Phenomena and Parameters Important to Burnup Credit  

Microsoft Academic Search

Since the mid-1980s, a significant number of studies have been directed at understanding the phenomena and parameters important to implementation of burnup credit in out-of-reactor applications involving pressurized-water-reactor (PWR) spent fuel. The efforts directed at burnup credit involving boiling-water-reactor (BWR) spent fuel have been more limited. This paper reviews the knowledge and experience gained from work performed in the US

C. V. Parks; M. D. DeHart; J. C. Wagner

2001-01-01

211

Breakdown phenomena in high power klystrons  

SciTech Connect

In the course of developing new high peak power klystrons at SLAC, high electric fields in several regions of these devices have become an important source of vacuum breakdown phenomena. In addition, a renewed interest in breakdown phenomena for nanosecond pulse, multi-megavolt per centimeter fields has been sparked by recent R and D work in the area of gigawatt RF sources. The most important regions of electrical breakdown are in the output cavity gap area, the RF ceramic windows, and the gun ceramic insulator. The details of the observed breakdown in these regions, experiments performed to understand the phenomena and solutions found to alleviate the problems will be discussed. Recently experiments have been performed on a new prototype R and D klystron. Peak electric fields across the output cavity gaps of this klystron exceed 2 MV/cm. The effect of peak field duration (i.e. pulse width) on the onset of breakdown have been measured. The pulse widths varied from tens of nanoseconds to microseconds. Results from these experiments will be presented. The failure of ceramic RF windows due to multipactor and puncturing was an important problem to overcome in order that our high power klystrons would have a useful life expectancy. Consequently many studies and tests were made to understand and alleviate window breakdown phenomena. Some of the results in this area, especially the effects of surface coatings, window materials and processing techniques and their effects on breakdown will be discussed. Another important source of klystron failure in the recent past at SLAC has been the puncturing of the high voltage ceramic insulator in the gun region. A way of alleviating this problem has been found although the actual cause of the puncturing is not yet clear. The ''practical'' solution to this breakdown process will be described and a possible mechanism for the puncturing will be presented. 9 refs., 5 figs., 3 tabs.

Vlieks, A.E.; Allen, M.A.; Callin, R.S.; Fowkes, W.R.; Hoyt, E.W.; Lebacqz, J.V.; Lee, T.G.

1988-03-01

212

Natural phenomena hazards site characterization criteria  

SciTech Connect

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.

Not Available

1994-03-01

213

Electrokinetic Phenomena in Homogeneous Cylindrical Pores  

Microsoft Academic Search

The electrokinetic phenomena occurring in homogeneous cylindrical pores containing symmetric electrolytes are studied. The local relations for flow in the pores (Nernst–Planck and Navier–Stokes equations) are developed. The analysis includes a numerical solution of the nonlinear Poisson–Boltzmann equation. The integral expressions of the phenomenological coefficients coupling the solvent flow and the electrical current with the hydrostatic pressure and the electrical

Anthony Szymczyk; Boujemaa Aoubiza; Patrick Fievet; Jacques Pagetti

1999-01-01

214

Further investigations of oblique hypervelocity impact phenomena  

NASA Technical Reports Server (NTRS)

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

Schonberg, William P.

1988-01-01

215

Search for collective phenomena in hadron interactions  

SciTech Connect

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.

Kokoulina, E. S., E-mail: kokoulin@sunse.jinr.ru; Nikitin, V. A., E-mail: nikitin@sunse.jinr.ru; Petukhov, Y. P., E-mail: Yuri.Petukhov@ihep.r [LHEP, JINR (Russian Federation); Karpov, A. V., E-mail: karpov@dm.komisc.ru; Kutov, A. Ya., E-mail: kutov@dm.komisc.r [Komi SC UrD RAS, Department of Mathematics (Russian Federation)

2010-12-15

216

Physical mechanism of membrane osmotic phenomena  

SciTech Connect

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.

Guell, D.C. [Los Alamos National Lab., NM (United States)] [Los Alamos National Lab., NM (United States); Brenner, H. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Chemical Engineering] [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Chemical Engineering

1996-09-01

217

Pseudogap phenomena in ultracold atomic Fermi gases  

NASA Astrophysics Data System (ADS)

The pairing and superfluid phenomena in a two-component ultracold atomic Fermi gas is an analogue of Cooper pairing and superconductivity in an electron system, in particular, the high T c superconductors. Owing to the various tunable parameters that have been made accessible experimentally in recent years, atomic Fermi gases can be explored as a prototype or quantum simulator of superconductors. It is hoped that, utilizing such an analogy, the study of atomic Fermi gases may shed light to the mysteries of high T c superconductivity. One obstacle to the ultimate understanding of high T c superconductivity, from day one of its discovery, is the anomalous yet widespread pseudogap phenomena, for which a consensus is yet to be reached within the physics community, after over 27 years of intensive research efforts. In this article, we shall review the progress in the study of pseudogap phenomena in atomic Fermi gases in terms of both theoretical understanding and experimental observations. We show that there is strong, unambiguous evidence for the existence of a pseudogap in strongly interacting Fermi gases. In this context, we shall present a pairing fluctuation theory of the pseudogap physics and show that it is indeed a strong candidate theory for high T c superconductivity.

Chen, Qijin; Wang, Jibiao

2014-10-01

218

Bion and Tustin: the autistic phenomena.  

PubMed

This article examines the implications of the proposal of autistic transformations within the general context of Bion's theory of Transformations. The aim is to confirm the coherence of this proposal of autistic transformations within the overall structure of Bion's theory of Transformations. She examines the relation between emotional links and their negatives, particularly -K. She questions in which of the dimensions of the mind the autistic phenomena are located, the relation between autistic phenomena and beta elements, and where to place them in the Grid. The author tries to form metapsychological support for the incorporation of the autistic area in Bion's theory of Transformations. She argues that, despite the incongruence and imprecision of this incorporation, such autistic phenomena cannot be excluded from the complexus of the human mind and should therefore be accounted for in Bion's transformations. She discusses the idea that the theory of transformations includes the field of the neurosis and psychosis and deals with emotions, whereas the autistic area is dominated by sensations. The author asks how to add the autistic area to Bion's theory. Clinical material of a child for whom the non-psychotic part of the personality predominates and who presents autistic nuclei provides material for the discussion. PMID:23924328

Korbivcher, Celia Fix

2013-08-01

219

Stability and restoration phenomena in competitive systems  

NASA Astrophysics Data System (ADS)

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.

Uechi, Lisa; Akutsu, Tatsuya

2013-10-01

220

Atmospheric Dust  

NSDL National Science Digital Library

Atmospheric dust storms are common in many of the world's semi-arid and arid regions and can impact local, regional, and even global weather, agriculture, public health, transportation, industry, and ocean health. This module takes a multifaceted approach to studying atmospheric dust storms. The first chapter examines the impacts of dust storms, the physical processes involved in their life cycle, their source regions, and their climatology. The second chapter explores satellite products (notably dust RGBs) and dust models used for dust detection and monitoring, and presents a process for forecasting dust storms. The third and final chapter of the module examines the major types of dust storms: those that are synoptically forced, such as pre- and post-frontal dust storms and those induced by large-scale trade winds; and those caused by mesoscale systems such as downslope winds, gap flow, convection, and inversion downburst storms.

2014-09-14

221

Atmospheric Modeling  

Microsoft Academic Search

\\u000a Air quality models simulate the atmospheric concentrations and deposition fluxes to the Earth’s surface of air pollutants\\u000a by solving the mass conservation equations that represent the emissions, transport, dispersion, transformations and removal\\u000a of those air pollutants and associated chemical species. Contemporary air quality models can be grouped into two major categories:\\u000a (1) models that calculate the concentrations of air pollutants

Christian Seigneur; Robin Dennis

222

The Atmosphere  

NSDL National Science Digital Library

The lessons at this website were prepared to introduce 5th-8th grade students to the fundamental principles of the earth's atmosphere: history, composition, and structure. Includes three pages of information and features to allow for exploration and expansion of current knowledge. In addition, there are four activities to develop performance skills, not only in science, but in math and language arts as well. Links to external sites also included.

223

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...

224

Work on Planetary Atmospheres and Planetary Atmosphere Probes  

NASA Technical Reports Server (NTRS)

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

Lester, Peter

1999-01-01

225

Natural phenomena and the senses : linking memory and corporeal experience  

E-print Network

How could the experience of our rituals be made more meaningful? Our experience of ritual exists as an exchange between our memory and natural phenomena in a place over time. These place specific phenomena are filtered by ...

Pitts, William Edward, 1976-

2002-01-01

226

Transport Phenomena in Polymer Electrolyte Membranes I. Modeling Framework  

E-print Network

Transport Phenomena in Polymer Electrolyte Membranes I. Modeling Framework J. Fimrite, H and recently proposed models for transport phenomena in polymer electrolyte membranes. Key experimental manuscript received March 18, 2005. Available electronically July 25, 2005. Polymer electrolyte membrane fuel

Struchtrup, Henning

227

Atmospheric control systems  

NASA Technical Reports Server (NTRS)

Viewgraphs on atmospheric control systems are presented. Techniques to maintain atmospheric control parameters are identified. Fuzzy logic control law is mentioned for application to atmospheric control.

Mankamyer, Melanie

1990-01-01

228

Atmospheric science  

NASA Technical Reports Server (NTRS)

The following types of experiments for a proposed Space Station Microgravity Particle Research Facility are described: (1) growth of liquid water drop populations; (2) coalescence; (3) drop breakup; (4) breakup of freezing drops; (5) ice nucleation for large aerosols or bacteria; (6) scavenging of gases, for example, SO2 oxidation; (7) phoretic forces, i.e., thermophoresis versus diffusiophoresis; (8) Rayleigh bursting of drops; (9) charge separation due to collisions of rimed and unrimed ice; (10) charged drop dynamics; (11) growth of particles in other planetary atmospheres; and (12) freezing and liquid-liquid evaporation. The required capabilities and desired hardware for the facility are detailed.

Hamill, Patrick; Ackerman, Thomas; Clarke, Antony; Goodman, Jindra; Levin, Zev; Tomasko, Martin; Toon, O. Brian; Whitten, Robert

1987-01-01

229

Studies of Novel Quantum Phenomena in Ruthenates  

SciTech Connect

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).

Mao, Zhiqiang

2011-04-08

230

Temporal Variations in Jupiter's Atmosphere  

NASA Technical Reports Server (NTRS)

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.

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

231

Enforced Development Of The Earth's Atmosphere  

E-print Network

We review some basic issues of the life-prescribed development of the Earth's system and the Earth's atmosphere and discourse the unity of Earth's type of life in physical and transcendental divisions. In physical division, we exemplify and substantiate the origin of atmospheric phenomena in the metabolic pathways acquired by the Earth's life forms. We are especially concerned with emergence of pro-life superficial environments under elaboration of the energy transformations. Analysis of the coupling phenomena of elaborated ozone-oxygen transformation and Arctic bromine explosion is provided. Sensing is a foundation of life and the Earth's life. We offer our explanation of human-like perception, reasoning and creativity. We suggest a number of propositions about association of transcendental and physical divisions and the purpose of existence. The study relates to the tradition of natural philosophy which it follows. The paper is suitable for the popular reading.

M. Iudin

2010-07-28

232

Fast Particle Methods for Multiscale Phenomena Simulations  

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

233

Depicting Fire and Other Gaseous Phenomena Using Diffusion Processes  

E-print Network

Depicting Fire and Other Gaseous Phenomena Using Diffusion Processes Jos Stam Eugene Fiume significant innovation is the reformulation and solution of the advection­diffusion equation for densities the evolution of gaseous phenomena. Keywords: fire, smoke, gaseous phenomena, diffusion, advec­ tion, warped

Toronto, University of

234

Hidden Threshold Phenomena for Fixed-Density SAT-formulae  

Microsoft Academic Search

Experimental evidence is presented that hidden threshold phenomena exist for fixed density random 3-SAT formulae. At such fixed densities the (sub-optimal) average Horn fraction (computed with a spe- cially designed algorithm) appears to be a parameter with respect to which these phenomena can be measured. This paper investigates the eects of density and size on the observed phenomena.

Hans Van Maaren; Linda Van Norden

2003-01-01

235

Signal cancellation phenomena in adaptive antennas: Causes and cures  

Microsoft Academic Search

Conventional adaptive beamformers utilizing some form of automatic minimization of mean square error exhibit signal can- cellation phenomena when adapting rapidly. These effects result from adaptive interaction between signal and interference, when signal and interference are received simultaneously. Similar phenomena have been observed and analyzed in relatively simple adaptive noise can- celling systems. A study of these phenomena in the

BERNARD WIDROW; KENNETH M. DUVALL; RICHARD P. GOOCH; WILLIAM C. NEWMAN

1982-01-01

236

Petrovay: Solar physics Activity phenomena 1 Overall structure: umbra + penumbra.  

E-print Network

Petrovay: Solar physics Activity phenomena 1 SUNSPOTS Overall structure: umbra + penumbra in decaying spots (hysteresis-like behaviour). #12;Petrovay: Solar physics Activity phenomena 1 Temperature: the effect is probably not real. #12;Petrovay: Solar physics Activity phenomena 1 Magnetic field: B0 2500

Petrovay, Kristóf

237

Petrovay: Solar physics Activity phenomena 2 SOLAR PROMINENCES  

E-print Network

Petrovay: Solar physics Activity phenomena 2 SOLAR PROMINENCES History: 12th­18th century: sporadic (Zirin & Severny) #12;Petrovay: Solar physics Activity phenomena 2 Classification Eruptive prominence in a sunspot. From their end matter flows into spot. #12;Petrovay: Solar physics Activity phenomena 2 Filaments

Petrovay, Kristóf

238

ISOTROPIC DAMAGE PHENOMENA IN SATURATED POROUS MEDIA: A BEM FORMULATION  

E-print Network

ISOTROPIC DAMAGE PHENOMENA IN SATURATED POROUS MEDIA: A BEM FORMULATION EDUARDO TOLEDO DE LIMA PHENOMENA IN SATURATED POROUS MEDIA: A BEM FORMULATION A thesis submitted in partial satisfaction Toledo L732i Isotropic damage phenomena in saturated porous media: a bem formulation / Eduardo Toledo

239

High-temperature phenomena in flares  

SciTech Connect

High temperature phenomena occurring in solar flares are reviewed based on hard X-ray images and spectral analyses of highly ionized iron lines observed aboard the Hinotori spacecraft. Five basic flare components are proposed, i.e., impulsive (I); gradual hard (GH); thermal (T); quasi thermal (QT); and hot thermal (HT) components. Every flare showed some combination of the five components. It is pointed out that data for energy release and transport for each component would give a lot of variety to the hard X-ray image, spectrum and time history of X-rays. 26 references.

Takakura, T.; Tanaka, K.

1984-01-01

240

Complex Synchronization Phenomena in Ecological Systems  

NASA Astrophysics Data System (ADS)

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.

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

2002-07-01

241

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

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

242

Research on atmospheric volcanic emissions - An overview  

NASA Technical Reports Server (NTRS)

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.

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

243

Short pulse phenomena produced with long pulses  

NASA Astrophysics Data System (ADS)

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 [1-3]. 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^+ [4]. 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. [1] M. F. Kling et al., Science 312, 246 (2006). [2] M. Kremer et al., Phys. Rev. Lett. 103, 213003 (2009). [3] V. Roudnev, B. D. Esry, and I. Ben-Itzhak, Phys. Rev. Lett. 93, 163601 (2004). [4] J. H. Posthumus et al. J. Phys. B: At. Mol. Opt. Phys. 28, 623 (2004).

Hernández, J. V.; Esry, B. D.

2011-06-01

244

Animal network phenomena: insights from triadic games  

NASA Astrophysics Data System (ADS)

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.

Mesterton-Gibbons, Mike; Sherratt, Tom N.

245

Physical phenomena and the microgravity response  

NASA Technical Reports Server (NTRS)

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.

Todd, Paul

1989-01-01

246

WHC natural phenomena hazards mitigation implementation plan  

SciTech Connect

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.

Conrads, T.J.

1996-09-11

247

TSDC spectroscopy of relaxational and interfacial phenomena.  

PubMed

Applications of thermally stimulated depolarisation current (TSDC) technique to a variety of systems with different dispersion phases such as disperse and porous metal oxides, polymers, liquid crystals, amorphous and crystalline solids, composites, solid solutions, biomacromolecules, cells, tissues, etc. in gaseous or liquid dispersion media are analysed. The effects of dipolar, direct current (dc) and space charge relaxations are linked to the temperature dependent mobility of molecules, their fragments, protons, anions, and electrons and depend on thermal treatment, temperature and field intensity of polarisation, heating rate on depolarisation or cooling rate on polarisation. Features of the relaxation mechanisms are affected not only by the mentioned factors but also by morphological, structural and chemical characteristics of materials. The interfacial phenomena, especially the role of interfacial water, received significant attention on analysis of the TSDC data. Comparison of the data of TSDC and dielectric relaxation spectroscopy (DRS), differential scanning calorimetry (DSC), 1H NMR spectroscopy with layer-by-layer freezing-out of bulk and interfacial water, adsorption/desorption of nitrogen, water and dissolved organics demonstrates high sensitivity and information content of the TSDC technique, allowing a deeper understanding of interfacial phenomena. PMID:17188637

Gun'ko, V M; Zarko, V I; Goncharuk, E V; Andriyko, L S; Turov, V V; Nychiporuk, Y M; Leboda, R; Skubiszewska-Zieba, J; Gabchak, A L; Osovskii, V D; Ptushinskii, Y G; Yurchenko, G R; Mishchuk, O A; Gorbik, P P; Pissis, P; Blitz, J P

2007-02-28

248

Uncommon corrosion phenomena of archaeological bronze alloys  

NASA Astrophysics Data System (ADS)

In the framework of the EFESTUS project (funded by the European Commission, contract No. ICA3-CT-2002-10030) the corrosion products of a large number of archaeological bronze artefacts are investigated by means of the combined use of scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD) and optical microscopy (OM) and tentative correlation of their nature with the chemical composition of the artefacts and the burial context is proposed. The results provide good insight into the corrosion layers and evidence in some bronze Roman coins and artefacts; the occurrence of uncommon corrosion phenomena that give rise to the formation of a yellowish-green complex chlorine-phosphate of lead (pyromorphite, (PbCl)Pb4(PO4)3) and of a gold-like thick layer of an iron and copper sulphide (chalcopyrite, CuFeS2). The micro-chemical and micro-structural results show that the coins were buried in a soil enriched in phosphorus for the accidental presence of a large amount of decomposing fragments of bones or in an anaerobic and humus rich soil where the chalcopyrite layer has been produced via the interaction between the iron of the soil, the copper of the coin and the sulphur produced by the decomposition of organic matter in an almost oxygen free environment. Finally, some unusual periodic corrosion phenomena occurring in high tin bronze mirrors found at Zama (Tunisia) are described.

Ingo, G. M.; de Caro, T.; Riccucci, C.; Khosroff, S.

2006-06-01

249

University of Oxford: Atmospheric, Oceanic, and Planetary Physics  

NSDL National Science Digital Library

The University of Oxford's Atmospheric, Oceanic, and Planetary Physics group "focuses on the study of physical processes in the atmospheres and oceans of the Earth and other planets, using experimental and theoretical techniques." Users can discover the group's innumerable projects and research tools in the areas involving the development of instruments and carrying out experiments mostly on satellites; analyses of data; and modeling and theoretical work related primarily to climate change, the middle atmosphere, planetary atmospheres, and to laboratory experiments on fluids. Individuals can find informational materials about its facilities and capabilities. The website answers a host of questions related to climate change, the ozone, and planetary phenomena.

250

Mathematical methods of studying physical phenomena  

NASA Astrophysics Data System (ADS)

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 co

Man'ko, Margarita A.

2013-03-01

251

Establishment of the New Ecuadorian Solar Physics Phenomena Division  

NASA Astrophysics Data System (ADS)

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

Lopez, E. D.

2014-02-01

252

Ultra-enhanced spring branch growth in CO 2-enriched trees: can it alter the phase of the atmosphere’s seasonal CO 2 cycle?  

Microsoft Academic Search

Since the early 1960s, the declining phase of the atmosphere’s seasonal CO2 cycle has advanced by approximately 7 days in northern temperate latitudes, possibly as a result of increasing temperatures that may be advancing the time of occurrence of what may be called ‘climatological spring.’ However, just as several different phenomena are thought to have been responsible for the concomitant

Craig D Idso; Sherwood B Idso; Bruce A Kimball; Hyoung-Shin Park; J. Kenneth Hoober; Robert C Balling

2000-01-01

253

Lunar orbital photography of astronomical phenomena.  

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

254

On the physical origin of fatigue phenomena  

E-print Network

The fractional power-law material behavior has been investigated within the framework of a modified mean field theory, in which high-temperature structure precursors in a crystalline or polycrystalline material are treated as a partially ordered liquid over a wide range of temperature. By doing so, the relaxation behavior of the material can be studied via a modified Landau-Khalatnikov equation. It then becomes clear that, as the special cases of the fractional power-law behavior, seemingly quite different fatigue phenomena and physical deterioration are governed by a fundamental physical phenomenon, i.e., the competition between ordered structures and partially ordered high-temperature structure precursors during a series of atomic relaxation processes.

John Y. Fu

2012-11-17

255

Threshold Phenomena in a Throbbing Complex Plasma  

SciTech Connect

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

Mikikian, Maxime; Coueedel, Lenaiec; Cavarroc, Marjorie; Tessier, Yves; Boufendi, Laiefa [GREMI, Groupe de Recherches sur l'Energetique des Milieux Ionises, UMR6606, CNRS/Universite d'Orleans, 14 rue d'Issoudun, BP6744, 45067 Orleans Cedex 2 (France)

2010-08-13

256

Critical phenomena in N=2* plasma  

E-print Network

We use gauge theory/string theory correspondence to study finite temperature critical behaviour of mass deformed N=4 SU(N) supersymmetric Yang-Mills theory at strong coupling, also known as N=2* gauge theory. For 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.

A. Buchel; C. Pagnutti

2010-10-16

257

Novel complex phenomena in ferroelectric nanocomposites.  

PubMed

A first-principles-based effective Hamiltonian is used to investigate finite-temperature properties of ferroelectric nanocomposites made of periodic arrays of ferroelectric nanowires embedded in a matrix formed by another ferroelectric material. Novel transitions and features related to flux-closure configurations are found. Examples include (i) a vortex core transition, that is characterized by the change of the vortex cores from being axisymmetric to exhibiting a 'broken symmetry'; (ii) translational mode of the vortex cores; (iii) striking zigzag dipolar chains along the vortex core axis; and (iv) phase-locking of ferroelectric vortices accompanied by ferroelectric antivortices. These complex phenomena are all found to coexist with a spontaneous electrical polarization aligned along the normal of the plane containing the vortices. PMID:22968903

Louis, Lydie; Kornev, Igor; Geneste, Grégory; Dkhil, Brahim; Bellaiche, L

2012-10-10

258

Novel nuclear phenomena in quantum chromodynamics  

SciTech Connect

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.

Brodsky, S.J.

1987-08-01

259

Geometrical-numerical approach to diffraction phenomena.  

PubMed

The calculation of diffracted fields is considered by means of a geometrical analysis of the incoming wave into semiperiodic zones in the aperture plane, followed by a numerical process for addition of the contributions corresponding to the semiperiodic zones. This general approach constitutes a novel interpretation of diffraction phenomena that permits exact evaluation of the mathematical expressions of diffraction theory and overcomes the limitations of any approximation. The method is illustrated by analysis of two important configuration in optics: the pinhole camera, for which we deduce the optimum radius for imaging, and the diffraction of a spherical converging wave through a circular aperture, from which we determine the limit of the validity of the Fraunhofer approximation (i.e., of the Airy pattern) and the influence of the obliquity factor. PMID:18033540

Bosch, S; Ferré-Borrull, J

2001-02-15

260

Hadronic and nuclear phenomena in quantum chromodynamics  

SciTech Connect

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.

Brodsky, S.J.

1987-06-01

261

Single event phenomena: Testing and prediction  

NASA Technical Reports Server (NTRS)

Highly integrated microelectronic devices are often used to increase the performance of satellite systems while reducing the system power dissipation, size, and weight. However, these devices are usually more susceptible to radiation than less integrated devices. In particular, the problem of sensitivity to single event upset and latchup is greatly increased as the integration level is increased. Therefore, a method for accurately evaluating the susceptibility of new devices to single event phenomena is critical to qualifying new components for use in space systems. This evaluation includes testing devices for upset or latchup and extrapolating the results of these tests to the orbital environment. Current methods for testing devices for single event effects are reviewed, and methods for upset rate prediction, including a new technique based on Monte Carlo simulation, are presented.

Kinnison, James D.

1992-01-01

262

Boundary quantum critical phenomena with entanglement renormalization  

SciTech Connect

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.

Evenbly, G.; Pfeifer, R. N. C.; Tagliacozzo, L.; McCulloch, I. P.; Vidal, G. [School of Physical Sciences, University of Queensland, Queensland 4072 (Australia); Pico, V.; Iblisdir, S. [Depto. Estructura i Constituents de la Materia, Universitat Barcelona, 08028 Barcelona (Spain)

2010-10-15

263

Critical phenomena in N=2* plasma  

SciTech Connect

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.

Buchel, Alex [Department of Applied Mathematics University of Western Ontario London, Ontario N6A 5B7 (Canada); Perimeter Institute for Theoretical Physics Waterloo, Ontario N2J 2W9 (Canada); Pagnutti, Chris [Department of Applied Mathematics University of Western Ontario London, Ontario N6A 5B7 (Canada)

2011-02-15

264

Psychic phenomena and early emotional states.  

PubMed

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

Reiner, Annie

2004-06-01

265

Correlated Spin Phenomena in Molecular Systems  

NASA Astrophysics Data System (ADS)

While a great deal of work has been carried out on molecular magnets, the spatial distribution of the spin wave function and the many body interactions between the delocalized molecular spin and its surrounding electrons can now be obtained with atomic scale resolution with the scanning tunneling microscope (STM). The combination of surface science, self-assembly, and STM enables correlated spin phenomena, such as the Kondo state, to be probed in a wide range of well characterized systems from single molecules to a two-dimensional lattice of interacting spins. Nonlocality, Kondo gap, and the Kondo lattice in correlated electron physics are revealed by the atomic-scale spatial resolution and high energy resolution spectroscopy and imaging with the STM from oxygen to porphyrins and phthalocyanine molecules adsorbed on metal and oxide surfaces.

Ho, Wilson

2012-02-01

266

Real time animation of space plasma phenomena  

NASA Technical Reports Server (NTRS)

In pursuit of real time animation of computer simulated space plasma phenomena, the code was rewritten for the Massively Parallel Processor (MPP). The program creates a dynamic representation of the global bowshock which is based on actual spacecraft data and designed for three dimensional graphic output. This output consists of time slice sequences which make up the frames of the animation. With the MPP, 16384, 512 or 4 frames can be calculated simultaneously depending upon which characteristic is being computed. The run time was greatly reduced which promotes the rapid sequence of images and makes real time animation a foreseeable goal. The addition of more complex phenomenology in the constructed computer images is now possible and work proceeds to generate these images.

Jordan, K. F.; Greenstadt, E. W.

1987-01-01

267

Stokes Phenomena in Discrete Painlevé I  

E-print Network

In this study, we consider the asymptotic behaviour of the first discrete Painlev\\{e} equation in the limit as the independent variable becomes large. Using an asymptotic series expansion, we identify two types of solutions which are pole-free within some sector of the complex plane containing the positive real axis. Using exponential asymptotic techniques, we determine the Stokes Phenomena effects present within these solutions, and hence the regions in which the asymptotic series expression is valid. From a careful analysis of the switching behaviour across Stokes lines, we find that the first type of solution is uniquely defined, while the second type contains two free parameters, and that the region of validity may be extended for appropriate choice of these parameters.

N. Joshi; C. J. Lustri

2015-03-04

268

Transient Phenomena: Opportunities for New Discoveries  

NASA Technical Reports Server (NTRS)

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

Lazio, T. Joseph W.

2010-01-01

269

Surfactant-based critical phenomena in microgravity  

NASA Technical Reports Server (NTRS)

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.

Kaler, Eric W.; Paulaitis, Michael E.

1994-01-01

270

Critical Phenomena in Liquid-Liquid Mixtures  

NASA Astrophysics Data System (ADS)

Critical phenomena provide intriguing and essential insight into many issues in condensed matter physics because of the many length scales involved. Large density or concentration fluctuations near a system's critical point effectively mask the identity of the system and produce universal phenomena that have been well studied in simple liquid-vapor and liquid-liquid systems. Such systems have provided useful model systems to test theoretical predictions which can then be extended to more complicated systems. Along various thermodynamic paths, several quantities exhibit a simple power-law dependence close to the critical point. The critical exponents describing these relationships are universal and should depend only on a universality class determined by the order-parameter and spatial dimensionality of the system. Liquid gas, binary fluid mixtures, uniaxial ferromagnetism, polymer-solvent, and protein solutions all belong to the same (Ising model) universality class. The diversity of critical systems that can be described by universal relations indicates that experimental measurements on one system should yield the same information as on another. Our experimental investigations have tested existing theory and also extended universal behavior into new areas. By measuring the coexistence curve, heat capacity, thermal expansion and static light scattering (turbidity) in various liquid-liquid and polymer-solvent systems, we have determined critical exponents and amplitudes that have sometimes confirmed and other times challenged current theory. Recent experiments investigating the heat capacity and light scattering in a liquid-liquid mixture very close to the critical point will be discussed. This research is currently supported by The Petroleum Research Fund and by NASA grant NAG8-1433 with some student support from NSF-DMR 9619406.

Jacobs, D. T.

2000-04-01

271

Atmospheric electricity  

NASA Technical Reports Server (NTRS)

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.

1987-01-01

272

Atmospheres of the Giant Planets  

NASA Technical Reports Server (NTRS)

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.

Ingersoll, Andrew P.

2002-01-01

273

Electrical cycle in the Earth's atmosphere  

NASA Astrophysics Data System (ADS)

A qualitative physical picture of atmospheric electricity as a secondary phenomenon of atmospheric water circulation is presented using the key electrical atmospheric processes, their average observed parameters, and a detailed analysis of separate processes as the basis. The electrical processes begin with the charging of aerosols at kilometer altitudes due to aerosols of different aggregate states colliding with one another. Atmospheric electric currents arise from the fall speed difference (in cumulus clouds) between mass-different positively and negatively charged aerosols, resulting in aerosols with a negative charge of, on average, (25-30)e at the lower edge of a cloud. This creates an electric field between Earth and the cloud, and the subsequent penetration of streams of warm wet air into the cloud causes the atmosphere to electrically break down, thus producing lightning flashes. At the same time, these processes cause aerosols to grow and to fall as rain onto Earth. Processes in atmospheric air, including those involving aerosols, electrons, and ions, provide a unified physical picture of electric phenomena in the terrestrial atmosphere.

Smirnov, B. M.

2014-11-01

274

The Role of Family Phenomena in Posttraumatic Stress in Youth  

PubMed Central

Topic Youth face trauma that can cause posttraumatic stress (PTS). Purpose 1). To identify the family phenomena used in youth PTS research; and 2). Critically examine the research findings regarding the relationship between family phenomena and youth PTS. Sources Systematic literature review in PsycInfo, PILOTS, CINAHL, and MEDLINE. Twenty-six empirical articles met inclusion criteria. Conclusion Measurement of family phenomena included family functioning, support, environment, expressiveness, relationships, cohesion, communication, satisfaction, life events related to family, parental style of influence, and parental bonding. Few studies gave clear conceptualization of family or family phenomena. Empirical findings from the 26 studies indicate inconsistent empirical relationships between family phenomena and youth PTS, though a majority of the prospective studies support a relationship between family phenomena and youth PTS. Future directions for leadership by psychiatric nurses in this area of research and practice are recommended. PMID:21344778

Deatrick, Janet A.

2010-01-01

275

Astrophysical phenomena related to supermassive black holes  

NASA Astrophysics Data System (ADS)

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 tota

Pott, Jörg-Uwe

2006-12-01

276

The Jovian Atmospheres  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

277

Investigations of atmospheric dynamics using a CW Doppler sounder array  

NASA Technical Reports Server (NTRS)

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.

Rao, G. L.

1974-01-01

278

Spherical formations in the atmosphere as a physical phenomenon  

Microsoft Academic Search

This paper presents an attempt to elucidate the physical nature of the stable luminous spherical formations that are sometimes observed in the atmosphere. It is suggested that there may be a connection between some of these natural formations and Unidentified Flying Objects. Properties common to spherical formations and ball lightnings have been found. A mathematical model describing such natural phenomena

A. I. Mesenyashin

1995-01-01

279

University Corporation for Atmospheric Research: Digital Image Library  

NSDL National Science Digital Library

This site provides access to weather and climate imagery, including unique visuals of atmospheric and solar phenomena, pollution, clouds, research instruments, field projects, landscapes, and educational settings. It also contains links to other digital image sites and a place to store personally selected images for later viewing.

280

Spatially multiplexed optical MIMO imaging system in cloudy turbulent atmosphere  

Microsoft Academic Search

Active optical imaging is preferred over Radio Frequency (RF) counterparts due to its higher resolution, faster area search rate, and relatively easier interpretation by a human observer. However, in imaging through atmosphere one should consider dispersive effects of multiple scatterings and turbulence-induced wave perturbations, which give rise to intensity fluctuations, and wave-front distortions. All these phenomena broaden and distort the

M. Kavehrad; Z. Hajjarian; J. Fadlullah

2009-01-01

281

Living matter: the "lunar eclipse" phenomena.  

PubMed

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

Korpan, Nikolai N

2010-01-01

282

Pathways toward understanding Macroscopic Quantum Phenomena  

NASA Astrophysics Data System (ADS)

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.

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

2013-06-01

283

Data Processing for Atmospheric Phase Interferometers  

NASA Technical Reports Server (NTRS)

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.

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

2009-01-01

284

Half collision resonance phenomena in molecules  

SciTech Connect

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.

Maximo Garcia-Sucre (Universidad Central de Venezuela, Caracas (Venezuela)); Raseev, G. (Paris-11 Univ., 91 - Orsay (France)); Ross, S.C. (New Brunswick Univ., Fredericton, NB (Canada)) (eds.)

1991-01-01

285

Fluctuation phenomena in neurological local field potentials  

NASA Astrophysics Data System (ADS)

The study of noise and fluctuations has proven useful in a wide variety of disordered systems, from disordered condensed matter systems to noisy biological systems. Neurological signals termed local field potentials are characterized by apparently random fluctuations interspersed with periods of clear oscillatory activity. Numerous mathematical theories have been developed that describe the power spectrum that results from different fluctuation phenomena. Several of these theories are presented with discussions of how they may apply to local field potentials in the brain. Experiments and simulations are proposed that could help to clarify specific aspects of the fluctuation origins of local field potentials. Given long time series of neurological voltage fluctuations, it can be difficult to detect the occurrence of oscillatory activity. An analytical method is presented to identify the presence of oscillations within a signal. This method is verified through simulations and experiments on signals with known oscillations. Using this method, a previously unknown oscillation is detected, termed gamma50, that is recorded in the striatum of awake, behaving rats. The gamma50 signal is characterized by short bursts of coherent 50 Hz oscillations, and is found to be correlated with the initiation of movement. Preliminary experiments were conducted to identify the origin of gamma50 events. Data from these experiments is discussed along with remaining open research questions and future directions.

Masimore, Beth

2008-10-01

286

The Monitoring of Transient Lunar Phenomena  

NASA Astrophysics Data System (ADS)

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.

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

2011-05-01

287

Thermomechanical phenomena in high speed rubbing  

NASA Technical Reports Server (NTRS)

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.

Kennedy, F. E.

1980-01-01

288

Fractal properties of medium and seismoelectric phenomena  

NASA Astrophysics Data System (ADS)

Electrokinetic phenomena in a water-porous medium with a fractal structure above percolation threshold are theoretically investigated. Fracture zone with space-variable porosity is considered as a model of an earthquake hypocenter zone in which the electrokinetic current results from fluid filtration in a fractal pore network. A critical exponent of the streaming potential coefficient is found to depend on both the transport critical exponent and correlation length critical exponent. In this model, logarithmic dependence of electric field amplitude E on the earthquake magnitude M is derived which is compatible with the one observed by the VAN group. Without fractal properties, this form of dependence contradicts the empirical data. The electromagnetic field far from the hypocenter is calculated, which leads to the prediction of weak magnetic field variations. To explain the observed amplitude of VAN's Seismic Electric Signals (SES), the electric source must be at a distance of about 10 km from the registration point if the medium is homogeneous. Therefore, some conductive channel(s) are needed to explain the long distance selective SES transmission.

Surkov, V. V.; Uyeda, S.; Tanaka, H.; Hayakawa, M.

2002-07-01

289

High-Field Phenomena of Qubits.  

PubMed

Electron and nuclear spins are very promising candidates to serve as quantum bits (qubits) for proposed quantum computers, as the spin degrees of freedom are relatively isolated from their surroundings and can be coherently manipulated, e.g., through pulsed electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR). For solid-state spin systems, impurities in crystals based on carbon and silicon in various forms have been suggested as qubits, and very long relaxation rates have been observed in such systems. We have investigated a variety of these systems at high magnetic fields in our multifrequency pulsed EPR/ENDOR (electron nuclear double resonance) spectrometer. A high magnetic field leads to large electron spin polarizations at helium temperatures, giving rise to various phenomena that are of interest with respect to quantum computing. For example, it allows the initialization of both the electron spin as well as hyperfine-coupled nuclear spins in a well-defined state by combining millimeter and radio-frequency radiation. It can increase the T(2) relaxation times by eliminating decoherence due to dipolar interaction and lead to new mechanisms for the coherent electrical readout of electron spins. We will show some examples of these and other effects in Si:P, SiC:N and nitrogen-related centers in diamond. PMID:19946596

van Tol, Johan; Morley, G W; Takahashi, S; McCamey, D R; Boehme, C; Zvanut, M E

2009-12-01

290

Phantom black holes and critical phenomena  

E-print Network

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-Nordstr\\"om 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.

Mustapha Azreg-Aïnou; Glauber T. Marques; Manuel E. Rodrigues

2014-06-24

291

Basic ablation phenomena during laser thrombolysis  

NASA Astrophysics Data System (ADS)

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.

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

1997-05-01

292

Further shock tunnel studies of scramjet phenomena  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

293

Fingering phenomena at high surfactant concentrations  

NASA Astrophysics Data System (ADS)

The spreading of a soluble surfactant droplet on a pre-existing thin liquid layer is considered at concentrations beyond the critical micelle concentration (CMC). Lubrication theory is used to derive a coupled system of four two-dimensional nonlinear evolution equations for the film thickness, monomer interface and bulk concentrations and micellar concentration. These equations are closed by a nonlinear surfactant equation of state. Our numerical results for the base state indicate that increasing the mass of surfactant deposited leads to the development of a protuberance that appears at the edge of the drop. For a sufficiently large mass, this feature separates from the drop to form a distinct secondary front that lies behind a leading front, which usually accompanies the spreading process. The results of our transient growth analysis and transient numerical simulations indicate that these features are vulnerable to transverse perturbations leading to the formation of fingers. The results obtained in the present work appear to capture phenomena recently observed experimentally.

Matar, Omar K.

2005-11-01

294

Nanoscale phenomena in synthetic functional oxide heterostructures.  

PubMed

This paper reviews nanoscale phenomena such as polarization relaxation dynamics and piezoelectric characterization in model ferroelectric thin films and nanostructures using voltage-modulated scanning force microscopy. Using this technique we show the three-dimensional reconstruction of the polarization vector in lead zirconate titanate (PZT) thin films. Second, the time-dependent relaxation of remanent polarization in epitaxial PZT ferroelectric thin films, containing a uniform two-dimensional grid of 90 degrees domains (c-axis in the plane of the film), has been investigated extensively. The 90 degrees domain walls preferentially nucleate the 180 degrees reverse domains during relaxation. Relaxation occurs through the nucleation and growth of reverse 180 degrees domains, which subsequently coalesce and consume the entire region as a function of relaxation time. In addition we also present results on investigation of the relaxation phenomenon on a very local scale, where pinning and bowing of domain walls has been observed. We also show how this technique is used for obtaining quantitative information on piezoelectric constants and by engineering special structures, and how we realize ultrahigh values of piezoconstants. Last, we also show direct hysteresis measurements on nanoscale capacitors, where there is no observable loss of polarization in capacitors as small as 0.16 microm2 in area. PMID:12533230

Nagarajan, V; Ganpule, C S; Stanishevsky, A; Liu, B T; Ramesh, R

2002-08-01

295

On the Nature of Quantum Phenomena  

E-print Network

It is shown that a coherent understanding of all quantized phenomena, including those governed by unitary evolution equations as well as those related to irreversible quantum measurements, can be achieved in a scenario of successive nonequilibrium phase transitions, with the lowest hierarchy of these phase transitions occurring in a ``resonant cavity'' formed by the entire matter and energy content of the universe. In this formalism, the physical laws themselves are resonantly-selected and ordered in the universe cavity in a hierarchical manner, and the values of fundamental constants are determined through a Generalized Mach's Principle. The existence of a preferred reference frame in this scenario is shown to be consistent with the relational nature of the origin of physical laws. Covariant unitary evolution is shown to connect smoothly with the reduction of wavefunction in the preferred frame during quantum measurement. The superluminal nature of quantum processes in the lowest hierarchy coexists with the universal speed limit obeyed by processes in higher hierarchies. A natural quantum-to-classical transition is also obtained which is stable against the diffusive tendency of the unitary quantum evolution processes. In this formalism a realistic quasi-classical ontology is established for the foundations of quantum mechanics.

Xiaolei Zhang

2007-12-28

296

Rotary kilns - transport phenomena and transport processes  

SciTech Connect

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.

Boateng, A.

2008-01-15

297

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

NASA Technical Reports Server (NTRS)

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.

Bertani, A.

1982-01-01

298

Scientific Inquiry on Anomalous Atmospheric Light Phenomena: Past Research Gaps and New Methodological Goals  

NASA Astrophysics Data System (ADS)

On the basis of the experience of this author, a decade of scientific research on earthlights is amply discussed and pondered from the point of view of instrumental measurements. After an introduction that shows a brief synthesis of what has been done so far, all the different measurement techniques and tactical/strategic procedures that have been used so far or that are planned for the near future are discussed in detail. Constructive criticism on the gaps that emerged from this research is punctually pointed out. New procedural ideas are widely proposed and scientifically motivated in order to improve this research and to stimulate researchers on this field in order to search for an optimum common protocol.

Teodorani, M.

2009-12-01

299

Infrared characteristic radiation of water condensation and freezing in connection with atmospheric phenomena  

Microsoft Academic Search

This paper considers the emission of infrared characteristic radiation during the first order phase transitions of water (condensation and crystallization). Experimental results are analyzed in terms of their correspondence to the theoretical models. These models are based on the assumption that the particle's (atom, molecule, or cluster) transition from the higher energetic level (vapor or liquid) to a lower one

Vitali A. Tatartchenko

2010-01-01

300

RAMOS: A Space Mission With Real-Time Stereoscopy of Atmospheric Phenomena  

NASA Astrophysics Data System (ADS)

RAMOS (Russian American Observational Satellites), scheduled for launch in 2009, is a joint mission of the Russian Federation and the United States of America. Two low earth-orbit satellites with complementary instrument suites will fly in tandem orbits at an altitude of ˜ 500 km and a variable mean separation of ˜ 300 km. The satellites will be capable of simultaneous viewing of the same location on or above the earth's surface, allowing for real-time stereoscopic imaging of the earth's environment. The sensors suite is composed of pointable multifiltered infrared (1.5 - 7.5 ? m), visible, and ultraviolet imaging radiometers. The nominal spatial footprints are ˜ 100 m at the earth's surface. One satellite will have polarization capability, and the other will have an infrared spectrometer built into the radiometer. During its projected two-year lifetime, RAMOS will be used as a testbed for a variety of space-based measurements of the terrestrial environment that require real-time stereoscopy. These experiments will include: (1) simultaneous measurements of the altitudes and temperatures, to accuracies of ± 100 m and ± 2 K, respectively, of the cloud tops in the eyewalls of tropical cyclones, in order to test theoretical predictions that such measurements can provide, via remote sensing, an accurate determination of the intensity of a tropical cyclone; (2) simultaneous measurements of the altitudes and velocities of cloud fragments, to accuracies of ± 100;m and ± 10;m s-1, respectively, to determine the practicality and usefulness of such measurements for the purpose of numerical weather prediction; and (3) time-dependent tomography of volcanic plumes and of smoke clouds from forest fires and anthropogenic sources.

Joss, P. C.; Stair, A. T.; Humpherys, T.; Sinelshchikov, V.; Misnik, V.

2004-05-01

301

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

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

302

Twilight phenomena in the atmosphere of Venus during the 2004 inferior conjunction  

E-print Network

. A value f=0 correspond to the planet entirely projected on the Sun, tangent to its border. When f=0 passage from the black drop to a luminescent arc beyond the limb of the Sun is represented. The arc

Schneider, Glenn

303

Minicomets in the Solar System and in the Earth's Atmosphere and Related Phenomena  

NASA Astrophysics Data System (ADS)

We consider the history of discovery and justify the existence in the Solar system of a new class of bodies-minicomets, i.e., bodies of cometary nature and composition but of low mass. Two classes of minicomets are distinguished: icy ones similar to the Tunguska meteorite, and snow ones, which break up at high altitudes.

Bronshten, V. A.

2000-05-01

304

ABSTRACT A review of the research literature concerning the environmental consequences of increased levels of atmospheric  

E-print Network

; by the greenhouse effect, largely caused by atmospheric water vapor (H2O); and by other phenomena that are more levels of atmospheric carbon dioxide leads to the conclusion that increases during the 20th and early 21 carbon diox- ide has, however, markedly increased plant growth. Predictions of harmful climatic effects

Jacob, Bruce

305

On the Acceleration of the Secondary Cosmic Ray Component in Low Atmosphere by Thunderstorms  

NASA Astrophysics Data System (ADS)

During atmospheric stormy events, variations in the gamma ray intensities in the energy range from 50 keV to a few MeV have been observed. These phenomena can be attributed to variations of the electrical potential gradient in the lower atmosphere that can affect the cosmic ray charged particle energies. Some examples of the effect will be shown and discussed.

Cecchini, S.; Cattani, D.; Galli, M.; Giovannini, G.; Pagliarin, A.

2003-07-01

306

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

NASA Astrophysics Data System (ADS)

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.

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

2011-01-01

307

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

SciTech Connect

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.

Blanchat, T.K.; Allen, M.D.; Pilch, M.M. [Sandia National Labs., Albuquerque, NM (United States); Nichols, R.T. [Ktech Corp., Albuquerque, NM (United States)

1994-06-01

308

Investigation of collective phenomena in dusty plasmas  

NASA Astrophysics Data System (ADS)

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.

Ruhunusiri, Wellalage Don Suranga

309

CFD Analysis of Core Bypass Phenomena  

SciTech Connect

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

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

2009-11-01

310

CFD Analysis of Core Bypass Phenomena  

SciTech Connect

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

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

2010-03-01

311

Magnetoacoustic Phenomena in Saturated Porous Media  

NASA Astrophysics Data System (ADS)

This work deals with dynamic interaction between electromagnetic and hydrodynamic types of motions in a porous medium, saturated with electrolyte. The system of equations is a coupling of equations of the two-velocity continuous filtration theory and Maxwell equations in quasi-stationary approximation. The method of separation by the physical processes is used for numerical solution, and the hyperbolic system is approximated by the explicit expanded Godunov scheme, and the parabolic system is approximated by the inexplicit Crank-Nicolson scheme. Generation of the magnetic field was modeled in the process of 2D electrolyte filtration in a porous medium, which is considered to be conducing because of a double electric layer. An entrainment in the external magnetic field over the electrolyte flow into a porous medium is observed, and the location of magnetic field maximum relative to the inlet boundary is determined by the ratio of kinematic viscosity to magnetic viscosity. A rise of this ratio provides more intensive drag of a filtered liquid and increasing magnetic field, reached in a porous medium. Downward the flow the field decreases because of magnetic field diffusion. The problem with simultaneous excitation of acoustic and electromagnetic perturbations at the boundary of saturated porous medium was also considered, and this allows us to obtain additional knowledge about accompanying effects and phenomena, what is the main scientific and practical goal of geophysics and oil survey. This research was supported by the Russian Foundation for Basic Research grant 06-05-65110, by the President's grants NSh-1573.2003.5, and by the Russian Ministry Science and Education grant RNP.2.1.1.702.

Perepechko, Y.

2007-12-01

312

CHAPTER 1. COLLECTIVE PLASMA PHENOMENA 1 Collective Plasma  

E-print Network

CHAPTER 1. COLLECTIVE PLASMA PHENOMENA 1 Chapter 1 Collective Plasma Phenomena The properties of a medium are determined by the microscopic processes in it. In a plasma the microscopic processes is actually limited to a distance of order the Debye length in a plasma. On length scales longer than

Callen, James D.

313

Migraine aura and related phenomena: beyond scotomata and scintillations  

E-print Network

Migraine aura and related phenomena: beyond scotomata and scintillations MB Vincent1 & N Hadjikhani MB & Hadjikhani N. Migraine aura and related phenomena: beyond scotomata and scintillations. Cephalalgia 2007. London. ISSN 0333-1024 Migraine affects the cortical physiology and may induce dysfunction

Hadjikhani, Nouchine

314

Pendulum Phenomena and the Assessment of Scientific Inquiry Capabilities  

ERIC Educational Resources Information Center

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…

Zachos, Paul

2004-01-01

315

Field dependence, suggestibility and belief in paranormal phenomena  

Microsoft Academic Search

This paper examines the relationships between field dependence, suggestibility and belief in paranormal phenomena. In Experiment 1, 91 subjects underwent an hypnosis session to determine their suggestibility. They also completed a paranormal belief scale and a computer test of field dependence. It was shown that suggestibility and field dependence had positive and significant correlations with the belief in paranormal phenomena.

Andreas Hergovich

2003-01-01

316

Transport Phenomena in Polymer Electrolyte Membranes Jeffrey Anders Fimrite  

E-print Network

Transport Phenomena in Polymer Electrolyte Membranes by Jeffrey Anders Fimrite B.Eng., University a thorough review of the available literature on issues relevant to transport phenomena in polymer electrolyte membranes. The insight gained in the literature review is used in the development of a transport

Victoria, University of

317

Thermal and thermomechanical phenomena in laser material interaction  

Microsoft Academic Search

In recent years, laser technology has been widely used in materials processing, non-destructive detecting and characterizing. Knowledge of thermal and thermomechanical phenomena in laser material interaction is of great importance in terms of understanding and optimizing these processes. In this thesis, several aspects of these thermal and thermomechanical phenomena are studied. ^ First, the photoacoustic (PA) wave induced by periodical

Xinwei Wang

2001-01-01

318

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

NASA Astrophysics Data System (ADS)

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.

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

319

Interlayer interaction phenomena in novel materials  

NASA Astrophysics Data System (ADS)

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.

Pershoguba, Sergii

320

Role of defects in the supersolid phenomena  

NASA Astrophysics Data System (ADS)

We investigate the role of topological defects, particularly dislocations, in the observed phenomena of supersolidity---a state of matter with simultaneous long range crystalline order and superfluid behavior. First, we determine bound state solutions of the 2D Schrodinger equation with a dipole potential originating from the elastic effects of a single edge dislocation. Along with a variational estimate of the ground state energy, we numerically solve the eigenvalue problem and calculate the energy spectrum using methods of exact diagonalization and basis expansion. A comparison of the behavior of the calculated energy spectrum and that obtained from semiclassical considerations is briefly discussed. The quantum mechanics of the inverse square screw dislocation potential is briefly discussed and the ground state energy values calculated for different cut-offs to the potential. We next propose an explanation for the heat capacity peak observed by Lin et al. [Nature 449, 1025 (2007)], by developing a lattice gas model of desorption (absorption) of 3He impurities from dislocations in solid 4He. The thermodynamics of the model is discussed and the associated heat capacity is calculated. We find that for various 3He concentrations and suitable dislocation densities the heat capacity shows quantitative agreement with the experiment, suggesting that the specific heat peak observed in the experiments may be due to a Schottky anomaly. Finally, within a phenomenological Landau theory, we study the effect of an edge dislocation in promoting superfluidity in a Bose crystal. We couple the elastic strain field of the dislocation to the superfluid density, and use a linear analysis to show that superfluidity nucleates on the dislocation before occurring in the bulk of the solid. Moving beyond the linear analysis, we develop a systematic perturbation theory in the weakly nonlinear regime, and use this method to integrate out transverse degrees of freedom and derive a one-dimensional Landau equation for the superfluid order parameter. We then extend our analysis to a network of dislocation lines, and derive an XY model for the dislocation network by integrating over fluctuations in the order parameter. Our results show that the ordering temperature for the network has a sensitive dependence on the dislocation density, consistent with numerous experiments that find a clear connection between the sample quality and the supersolid response.

Goswami, Debajit

321

Saving the Phenomena in Medieval Astronomy  

NASA Astrophysics Data System (ADS)

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.

Seeskin, K.

2011-06-01

322

Optical studies of critical phenomena in fluids  

NASA Astrophysics Data System (ADS)

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 Delta? H for the binary mixture follows a power law Delta? 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.

Fameli, Nicola

2000-11-01

323

Solidification phenomena in metal matrix nanocomposites  

NASA Astrophysics Data System (ADS)

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.

de Cicco, Michael Peter

2009-12-01

324

Karstic Phenomena Susceptibility Map of MÉXICO  

NASA Astrophysics Data System (ADS)

Approximately 20% of the territory of México is underlain by karstifiable rocks, mostly limestones and in lesser proportions gypsum. The majority of these rocks are distributed along the eastern and southern Sierra Madre, the state of Chiapas and the Yucatán peninsula. Differences in geological structure, climate and geomorphic history have resulted in a great variety of karstic landscapes and types of forms. Several important population centers, including large cities with several million inhabitants and numerous smaller towns are built on karstic terrains and obtain their water supplies from karstic aquifers and/or dispose of their waste products on this type of terrain. Severe problems of waste disposal and aquifer contamination have occurred. Additionally, numerous instances of catastrophic collapse and formation of karstic sinkholes have been registered in the Mexican territory, which have affected many communities, roads and other infrastructure, and have even cost several lives. Lack of knowledge of the special characteristics of karstic terrains and their distribution has compounded these problems. As a first approach to these issues, the existing map of Mexican karst (Espinasa-Pereña, 2007) was modified according to the geotechnical classification proposed by Waltham & Fookes (2003). An important consideration taken into account is the difference in speed of development of karstic features depending on lithology, which makes karst developed in gypsum much more hazardous than limestone karst, and also the degree of soil coverage and the types of sinkholes developed on the cover. Also taken in consideration are the differences between karst developed in the Sierra Madre, with rocks highly deformed and fractured, and karst developed on the Yucatán peninsula with almost negligible deformation of the rocks. The resulting map will be useful to Civil Protection authorities as a tool in prognosticating possible affectations due to karstic phenomena. References: ESPINASA-PEREÑA, R., 2007, "El Karst de México", Mapa NA III 3, in Coll-Hurtado, A., Coord., "Nuevo Atlas Nacional de México", Instituto de Geografía, Universidad Nacional Autónoma de México. WALTHAM, A.C. and FOOKES, P.G., 2003, Engineering classification of karst ground conditions, Quarterly Journal of Engineering Geology and Hydrology, Vol. 36, pp. 101-118.

Espinasa-Pereña, R.

2013-05-01

325

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

SciTech Connect

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.

Schlicher, Bob G [ORNL] [ORNL; Abercrombie, Robert K [ORNL] [ORNL; Hively, Lee M [ORNL] [ORNL

2013-01-01

326

Individualization of the anisotropic phenomena of the imbalanced Nature  

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

327

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

NASA Technical Reports Server (NTRS)

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 uti

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

2014-01-01

328

Ball lightning and other meteorological phenomena  

NASA Astrophysics Data System (ADS)

The properties of ball lightning can all be explained on the basis of an approximate thermodynamic assessment of the chemical processes which must be occurring. Detailed explanations involve rather complex interactions between the various electrical, chemical and physical effects. There is no thermodynamic reason why high temperatures are needed to start the most crucial component - thermochemical refrigeration. Thus related chemical processes could have a wider application. After considering how the various forces combine in ball lightning and its close relatives, the possibility is explored that evidence already exists for similar, but simpler, combinations of forces. Such evidence is found both in the meteorological literature and in many of the early studies on condensation and steam phase electrochemistry. Chemical processes which can lead to charging of the earth and to thunderstorm electricity are considered, as are some very relevant properties of tornadoes. Related effects may also be responsible for the unexpectedly high temperature gradient found near the inner coma of Halley's Comet. The reported change in direction of the Tunguska bolide as well as its explosion in the atmosphere may also result from processes like those which occur in ball lightning. The physical chemistry of ions in saturated water vapour is not understood quantitatively and this ignorance is part of the reason ball lightning has seemed so strange. The same lack of information has also inhibited any follow-up of important laboratory findings related to droplet condensation. Suggestions for future work are made and some of the problems discussed.

Turner, D. J.

1998-01-01

329

DEMETER Observations of Equatorial Plasma Depletions and Related Ionospheric Phenomena  

NASA Astrophysics Data System (ADS)

DEMETER, the first micro-satellite of the CNES MYRIAD program, was launched from Baikonour on June 29, 2004 on a nearly circular, quasi helio-synchronous polar orbit at ~ 715 km altitude. The DEMETER mission focuses primarily on the search for a possible coupling between seismic activity and ionospheric disturbances as well as on the effects of natural phenomena such as tropospheric thunderstorms and man-made activities on the ionosphere. The scientific payload provides fairly complete measurements of the ionospheric plasma, energetic particles above ~ 70 keV, and plasma waves, up to 20 kHz for the magnetic and 3.3 MHz for the electric components. Several studies related to space weather and ionospheric physics have been conducted over the past years. Following a brief description of the payload and the satellite modes of operation, this presentation will focus on a set of results that provide a new insight into the physics of instabilities in the night-time equatorial ionosphere. The observations were performed during the major magnetic storm of November 2004. Deep plasma depletions were observed on several night-time passes at low latitudes characterized by the decrease of the plasma density by nearly 3 orders of magnitude relative to the undisturbed plasma, and a significant abundance of molecular ions. These features can be best interpreted as resulting from the rise of the F-layer above the satellite altitude over an extended region of the ionosphere. In one of the passes, DEMETER was operated in the Burst mode and the corresponding high resolution data allowed for the discovery of two unexpected phenomena. The first one is the existence of high intensity monochromatic wave packets at the LH frequency that develop during the decay phase of intense bursts of broadband LH turbulence. The broadband LH turbulence is triggered by whistlers emitted by lightning from atmospheric thunderstorms beneath the satellite. The second unexpected feature is the detection of a population of super-thermal ionospheric ions with a density of about 2-3% of the thermal ion population. The super- thermal ions appeared to be heated to temperatures of a few eV at times when LH turbulence and monochromatic wave packets are observed while the temperature of the core ion population is not affected. High time resolution plasma density measurements show the presence of strong small scale plasma irregularities in the depletions that scatter the high amplitude whistler waves and may lead to the development of strong LH turbulence and of monochromatic wave packets. The ensuing interaction between these waves and the ambient ions may lead to the formation of a super-thermal tail in the ion distribution function. Ion acceleration by LH turbulence and solitary waves is a commonly observed phenomenon along auroral magnetic field lines but, to our knowledge, this is the first time that a similar process has been observed in the equatorial ionosphere. These findings exemplify a novel coupling mechanism between the troposphere and the ionosphere: Under highly disturbed conditions at times of magnetic storms, part of the energy released by lightning and radiated as whistlers can dissipate in the equatorial ionosphere and produce super-thermal ion populations.

Berthelier, J.; Malingre, M.; Pfaff, R.; Jasperse, J.; Parrot, M.

2008-12-01

330

Analytical investigation of critical phenomena in MHD power generators  

NASA Technical Reports Server (NTRS)

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.

1980-01-01

331

Analytical investigation of critical phenomena in MHD power generators  

NASA Astrophysics Data System (ADS)

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.

1980-07-01

332

Middle atmospheric electrodynamics at low lattitude over India  

NASA Astrophysics Data System (ADS)

Low latitude middle atmospheric electrodynamics has a number of interesting features such as low flux of cosmic rays due to high cut-off rigidities, higher solar electromagnetic radiation intensities and mesospheric ionisation, large scale convection and wide-spread lightning phenomena, higher tropopause level and special characteristics associated with the equatorial electrojet. These special features play a vital role in governing the electrodynamics of the global middle atmosphere. In India, a well coordinated multi-institutional campaign was organised under MAP (Middle Atmosphere Programme) to carry out balloon and rocket borne experiments to measure electrical parameters of the middle atmosphere. The measured parameters include electron/ion densities and mobilities, polar ion conductivities and electric fields. The experiments were carried out during different seasons and solar activity epochs. The results obtained from these investigations are discussed and compared with similar measurements over the middle latitude stations to assess the integrated effect of the global atmospheric electrodynamic phenomenon.

Chakravarty, S. C.; Gupta, S. P.; Chandrasekaran, S.

1997-01-01

333

Models for aurora and airglow emissions from other planetary atmospheres  

NASA Technical Reports Server (NTRS)

Models for aurora and airglow emissions from planetary atmospheres other than the earth are surveyed, with emphasis on accomplishments of the last seven years. The goals of modeling the terrestrial planets and modeling the outer planets are very different. Because less is known about the atmospheres of the outer planets, models of their luminosity seek to provide information about the basic structure of the atmospheres and to identify the major production mechanisms. Models of the terrestrial planets have recently begun to address more complex questions about the abundances of trace and minor constituents, about transport phenomena, and about spatial and temporal variations in the atmosphere and in the processes that produce the emissions. In addition, there are a few instances in which models have been used to elucidate atomic and molecular processes that are difficult to study either in the terrestrial atmosphere or in the laboratory.

Fox, J. L.

1986-01-01

334

Irreducible imprecision in atmospheric and oceanic simulations  

PubMed Central

Atmospheric and oceanic computational simulation models often successfully depict chaotic space–time patterns, flow phenomena, dynamical balances, and equilibrium distributions that mimic nature. This success is accomplished through necessary but nonunique choices for discrete algorithms, parameterizations, and coupled contributing processes that introduce structural instability into the model. Therefore, we should expect a degree of irreducible imprecision in quantitative correspondences with nature, even with plausibly formulated models and careful calibration (tuning) to several empirical measures. Where precision is an issue (e.g., in a climate forecast), only simulation ensembles made across systematically designed model families allow an estimate of the level of relevant irreducible imprecision. PMID:17502623

McWilliams, James C.

2007-01-01

335

Certain relativistic phenomena in crystal optics  

NASA Astrophysics Data System (ADS)

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 ?¯.

Chee-Seng, Lim

1980-01-01

336

Synchro-ballistic recording of detonation phenomena  

SciTech Connect

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.

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

1997-09-01

337

Non-equilibrium fluctuation induced-phenomena in quantum electrodynamics  

E-print Network

We study fluctuation-induced phenomena in systems out of thermal equilibrium, resulting from the stochastic nature of quantum and thermal fluctuations of electromagnetic currents and waves. Specifically, we study radiative ...

Golyk, Vladyslav Alexander

2014-01-01

338

Depicting fire and other gaseous phenomena using diffusion processes  

Microsoft Academic Search

Developing a visually convincing model of fire, smoke, and othergaseousphenomenaisamongthemostdifficult andattractive problems in computer graphics. We have created new methods of animating a wide range of gaseous phenomena, including the particularlysubtleproblemofmodelling\\

Jos Stam; Eugene Fiume

1995-01-01

339

High speed imaging of transient non-Newtonian fluid phenomena  

E-print Network

In this thesis, I investigate the utility of high speed imaging for gaining scientific insight into the nature of short-duration transient fluid phenomena, specifically applied to the Kaye effect. The Kaye effect, noted ...

Gallup, Benjamin H. (Benjamin Hodsdon), 1982-

2004-01-01

340

Infrared thermometry study of nanofluid pool boiling phenomena  

E-print Network

Abstract Infrared thermometry was used to obtain first-of-a-kind, time- and space-resolved data for pool boiling phenomena in water-based nanofluids with diamond and silica nanoparticles at low concentration (<0.1 vol.%). ...

Gerardi, Craig

341

Novel resonant and light-guiding phenomena in photonics  

E-print Network

We investigate theoretically five novel resonant and light-guiding photonics phenomena. First, we develop a universal coupled mode theory (CMT) treatment of the freespace scattering of waves from resonant objects. This ...

Hamam, Rafif E. (Rafif Ezzat)

2010-01-01

342

Probing Cytological and Reproductive Phenomena by Means of Bryophytes.  

ERIC Educational Resources Information Center

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)

Newton, M. E.

1985-01-01

343

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...

344

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...

345

Simulation and design optimization for linear wave phenomena on metamaterials  

E-print Network

Periodicity can change materials properties in a very unintuitive way. Many wave propagation phenomena, such as waveguides, light bending structures or frequency filters can be modeled through finite periodic structures ...

Saà-Seoane, Joel

2011-01-01

346

Justifying Beliefs About Seance Phenomena in 19th Century Britain   

E-print Network

This study aims to discover how people in 19th century Britain justified their beliefs about séance phenomena, with a view to understanding how expressions of belief about the paranormal are constructed. Paranormal beliefs have been studied...

Stubbs, Harriet

2012-11-28

347

Novel applications of Maxwell's equations to quantum and thermal phenomena  

E-print Network

This thesis is concerned with the extension of Maxwell's equations to situations far removed from standard electromagnetism, in order to discover novel phenomena. We discuss our contributions to the efforts to describe ...

McCauley, Alexander P. (Alexander Patrick)

2011-01-01

348

Department of Energy Natural Phenomena Hazards Mitigation Program  

SciTech Connect

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.

Murray, R.C.

1993-09-01

349

Light flash phenomena induced by HzE particles  

NASA Technical Reports Server (NTRS)

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.

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

1980-01-01

350

Physics of the Sun and its Atmosphere  

NASA Astrophysics Data System (ADS)

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. Erdélyi -- 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.

Dwivedi, B. N.; Narain, U.

351

Atmospheric deposition to high-elevation forests  

SciTech Connect

Three important phenomena characterize atmospheric deposition to high-elevation forests: (1) multiple deposition mechanisms (wet, dry, and cloud deposition), (2) high rates of deposition, and (3) high spatial variability. The high rates of deposition are caused by changes in meteorological conditions with elevation, especially increasing wind speed and cloud immersion frequency. The high spatial variability of deposition is a result of the regulation of cloud and dry deposition rates by microclimatic and canopy structure conditions, which can be extremely heterogeneous in mountain landscapes. Spruce-fir forests are often [open quotes]hot spots[close quotes] of deposition when viewed in a landscape or regional context because of their elevation, exposure, and evergreen canopy. In this talk we will consider atmospheric depositions to high-elevation forests in both the northeastern and southeastern U.S., using field data and geographic information systems to illustrate deposition patterns.

Lovett, G.M.; Weathers, K.C.; Lindberg, S.E. (Institute of Ecosystem Studies, Millbrook, NY (United States) Oak Ridge National Lab., TN (United States))

1994-06-01

352

National Oceanic and Atmospheric Administration : Research Homepage  

NSDL National Science Digital Library

National Oceanic and Atmospheric Administration (NOAA) Research, conducted primarily through the NOAA Office of Oceanic and Atmospheric Research, drives the NOAA environmental products and services that protect life and property and promote sustainable economic growth. Research, conducted by in-house laboratories and by extramural programs, focuses on enhancing understanding of the environmental phenomena such as tornadoes, hurricanes, climate variability, solar flares, changes in the ozone, El Nino/La Nina events, fisheries productivity, ocean currents, deep sea thermal vents, and coastal ecosystem health. NOAA research also develops innovative technologies and observing systems. This clearinghouse website contains an explanation of various types of research conducted by NOAA. Users can access hot research topics, NOAA products and research organizations. This site also contains image galleries and photo albums chronicling NOAA research.

2003-01-01

353

Stellar atmospheric structural patterns  

NASA Technical Reports Server (NTRS)

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.

Thomas, R. N.

1983-01-01

354

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...

355

Atmospheric Science Experiment for Mars: ATMIS for the Netlander 2005 Mission  

NASA Technical Reports Server (NTRS)

ATMIS (Atmospheric and Meteorological Instrumentation System) is a versatile suite of atmospheric instrumentation to be accommodated onboard the Netlander Mission slated for launch in 2005. Four Netlanders are planned to form a geophysical measurement network on the surface of Mars. The atmospheric sciences are among the scientific disciplines benefiting most of the network concept. The goal of the ATMIS instrument is to provide new data on the atmospheric vertical structure, regional and global circulation phenomena, the Martian Planetary Boundary Layer (PBL) and atmosphere-surface interactions, dust storm triggering mechanisms, as well as the climatological cycles of H2O, dust and CO2. To reach the goal of characterization of a number of phenomena exhibiting both spatial and temporal variations, simultaneous observations of multiple variables at spatially displaced sites Deforming a network D are required. The in situ observations made by the ATMIS sensors will be supported by extensive modeling efforts. Additional information is contained in the original extended abstract.

Harri, A.-M.; Siili, T.; Angrilli, A.; Calcutt, S.; Crisp, D.; Larsen, S.; Polkko, J.; Pommereau, J.-P.; Malique, C.; Tillman, J. E.

1999-01-01

356

Atmospheric Nitrogen Fluorescence Yield  

NASA Technical Reports Server (NTRS)

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.

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

357

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

NASA Astrophysics Data System (ADS)

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 f

Eikerling, Michael

2011-06-01

358

Photochemistry in planetary atmospheres  

Microsoft Academic Search

Widely varying paths of evolutionary history, atmospheric processes, solar fluxes, and temperatures have produced vastly different planetary atmospheres. The similarities and differences between the earth atmosphere and those of the terrestrial planets (Venus and Mars) and of the Jovian planets are discussed in detail; consideration is also given to the photochemistry of Saturn, Uranus, Pluto, Neptune, Titan, and Triton. Changes

J. S. Levine; T. E. Graedel

1981-01-01

359

Computational Atmospheric Science  

NSDL National Science Digital Library

The goal of this online instructional workshop is to introduce participants to the theories and applications of atmospheric science computer modeling, specifically ozone formation and reactions in the atmosphere. Upon completion of the course, participants should understand the fundamental principles of ozone formation in the atmosphere and be able to understand and use numerical and computational science methods to study ozone science.

The Shodor Education Foundation, Inc.

360

Aircraft Performance: Atmospheric Pressure  

E-print Network

Aircraft Performance: Atmospheric Pressure FAA Handbook of Aeronautical Knowledge Chap 10 #12 ­ 21% Oxygen ­ 1% other gases (argon, helium, etc) · Most oxygen Atmospheric Pressure;High Density Altitude (worse performance) · High elevations · Low atmospheric pressures · High

361

Atmospheric Turbulence (METR 6103)  

E-print Network

: A First Course in Turbulence, The MIT Press, 300 pp; Garratt, J. R., 1992: The Atmospheric Boundary Layer in the atmospheric boundary and surface layers. Similarity and scaling techniques. Monin-Obukhov similarity theory of turbulence closures. Large eddy simulation of atmospheric boundary layer flows. Note: Any student

Fedorovich, Evgeni

362

Therapeutic potential of atmospheric neutrons  

PubMed Central

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 ?Gy 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

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

2010-01-01

363

Nonisothermal Pluto atmosphere models  

NASA Astrophysics Data System (ADS)

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.

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

1990-03-01

364

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

PubMed Central

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 ?m) 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

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

2012-01-01

365

Cosmic dust in the earth's atmosphere.  

PubMed

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

Plane, John M C

2012-10-01

366

Parameterized rotating convection for core and planetary atmosphere dynamics  

NASA Astrophysics Data System (ADS)

New types of convective instability and associated nonlinear phenomena in rapidly rotating spherical systems have been discovered through numerical simulations. The Prandtl number, defined as the ratio of the viscous and thermal diffusivities of a fluid, Pr = nu/kappa, plays a crucial role in determining the fundamental features of both the instabilities and the corresponding nonlinear convection. The results shed new light on regimes of convection in the earth's core and the atmospheres of the major planets.

Zhang, K.

1991-04-01

367

Directional Observations of Radio Noise from the Outer Atmosphere  

Microsoft Academic Search

ALTHOUGH many observations have been made in the past of the spectra of the radio emissions of the Earth's outer atmosphere in the frequency band 2-40 Kc.\\/s.1,2, it is only recently that a technique has been developed for continuously monitoring the occurrence of these phenomena3. This has revealed that radio noise bursts lasting some hours are normally associated with disturbances

G. R. A. Ellis; D. G. Cartwright

1959-01-01

368

On the Physics of the Critical Ionization Velocity Phenomena  

NASA Astrophysics Data System (ADS)

The interplay of collisional and collisionless phenomena in the interaction of a magnetoplasma streaming through neutral gas produces some of the most fascinating plasma physics phenomena. A key notion controlling such interactions is the existence of a "critical velocity" effect postulated in an ad hoc fashion by Alfvén, in his model of the formation of the solar system. Guided by recent laboratory and space experiments and plasma physics theory the author presents the basic plasma physics underlying the interaction. This is followed by a discussion of its relevance to the formation of the solar system and cometary tails, its controlling effect on plasma centrifuges and homopolar generators, and the fascinating possibility that critical velocity phenomena are controlling the space shuttle environment, transforming it into an artificial comet.

Papadopoulos, K.

369

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

SciTech Connect

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.

Mark Holbrook

2007-07-01

370

Direct observation of thitherto unobservable quantum phenomena by using electrons  

PubMed Central

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

Tonomura, Akira

2005-01-01

371

Bifurcation Phenomena in Two-Dimensional Piecewise Smooth Discontinuous Maps  

E-print Network

In recent years the theory of border collision bifurcations has been developed for piecewise smooth maps that are continuous across the border, and has been successfully applied to explain nonsmooth bifurcation phenomena in physical systems. However, many switching dynamical systems have been found to yield two-dimensional piecewise smooth maps that are discontinuous across the border. The theory for understanding the bifurcation phenomena in such systems is not available yet. In this paper we present the first approach to the problem of analysing and classifying the bifurcation phenomena in two-dimensional discontinuous maps, based on a piecewise linear approximation in the neighborhood of the border. We explain the bifurcations occurring in the static VAR compensator used in electrical power systems, using the theory developed in this paper. This theory may be applied similarly to other systems that yield two-dimensional discontinuous maps.

Biswambhar Rakshit; Manjul Apratim; Parag Jain; Soumitro Banerjee

2008-09-18

372

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

SciTech Connect

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.

none,

1992-07-01

373

Relativistic breakdown in planetary atmospheres  

SciTech Connect

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.

Dwyer, J. R. [Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, Florida 32901 (United States)

2007-04-15

374

RELAP5-3D code validation for RBMK phenomena  

SciTech Connect

The RELAP5-3D thermal-hydraulic code was assessed against Japanese Safety Experiment Loop (SEL) and Heat Transfer Loop (HTL) tests. These tests were chosen because the phenomena present are applicable to analyses of Russian RBMK reactor designs. The assessment cases included parallel channel flow fluctuation tests at reduced and normal water levels, a channel inlet pipe rupture test, and a high power, density wave oscillation test. The results showed that RELAP5-3D has the capability to adequately represent these RBMK-related phenomena.

Fisher, J.E.

1999-09-01

375

RELAP5-3D Code Validation for RBMK Phenomena  

SciTech Connect

The RELAP5-3D thermal-hydraulic code was assessed against Japanese Safety Experiment Loop (SEL) and Heat Transfer Loop (HTL) tests. These tests were chosen because the phenomena present are applicable to analyses of Russian RBMK reactor designs. The assessment cases included parallel channel flow fluctuation tests at reduced and normal water levels, a channel inlet pipe rupture test, and a high power, density wave oscillation test. The results showed that RELAP5-3D has the capability to adequately represent these RBMK-related phenomena.

Fisher, James Ebberly

1999-09-01

376

Risk in nuclear power plants due to natural hazard phenomena  

SciTech Connect

For the safety of nuclear power plants, it is important to identify potential areas of vulnerabilities to internal as well as external events to which nuclear power plants are exposed. This paper summarizes the risk in nuclear power plants due to natural hazard phenomena such as earthquakes, winds and tornadoes, floods, etc. The reported results are based on a limited number of probabilistic risk assessments (PRAS) performed for a few of the operating nuclear power plants within the United States. The summary includes an importance ranking of various natural hazard phenomena based on their contribution to the plant risk along with insights observed from the PRA studies.

Lu, S.C. [Lawrence Livermore National Lab., CA (United States)

1995-12-01

377

Fundamental investigation of duct/ESP phenomena. Final report  

SciTech Connect

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)

Brown, C.A. [Radian Corp., Austin, TX (United States); Durham, M.D. [ADA Technologies, Inc., Englewood, CO (United States); Sowa, W.A. [California Univ., Irvine, CA (United States). Combustion Lab.; Himes, R.M. [Fossil Energy Research Corp., Laguna Hills, CA (United States); Mahaffey, W.A. [CHAM of North America, Inc., Huntsville, AL (United States)

1991-10-21

378

Critical phenomena in the AdS/CFT duality  

E-print Network

We review black holes with second-order phase transition in string theory (R-charged black holes and holographic superconductors) and review their static and dynamic critical phenomena. Holographic superconductors have conventional mean-field values for static critical exponents, but R-charged black holes have unconventional ones. For dynamic universality class, holographic superconductors belong to model A, and R-charged black holes belong to model B in the classification of Hohenberg and Halperin. The analysis suggests that some black holes do obey the theory of critical phenomena in condensed matter physics.

Makoto Natsuume

2010-06-25

379

Theoretical interpretation of Traveling Interplanetary Phenomena and their solar origins  

NASA Technical Reports Server (NTRS)

A review is made of recent theoretical studies on Traveling Interplanetary Phenomena (TIP) and their possible solar origins in the context of mathematical methods and physical processes. Flare-generated interplanetary shocks are used as examples to illustrate the following set of contrasting approaches to the phenomena: analytical vs numerical, hydrodynamic vs magnetohydrodynamic, dissipative vs non-dissipative, continuum/macroscopic vs kinetic/microscopic. It is suggested in conclusion that future research should emphasize continuum/macroscopic physical processes together with the kinetic approach to deepen understanding of microscopic interactions.

Wu, S. T.

1980-01-01

380

Highly Evolved Exoplanet Atmospheres  

NASA Astrophysics Data System (ADS)

It has been found that sub-Neptune-sized planets, although not existing in our Solar System, are ubiquitous in our interstellar neighborhood. This revelation is profound because, due to their special sizes and proximity to their host stars, Neptune- and sub-Neptune-sized exoplanets may have highly-evolved atmospheres. I will discuss helium-dominated atmospheres as one of the outcomes of extensive atmospheric evolution on warm Neptune- and sub-Neptune-sized exoplanets. The spectral characteristics, and the formation conditions of the helium atmosphere, as applied to GJ 436 b, will be discussed. As the observations to obtain the spectra of these planets continue to flourish, we will have the opportunity to study unconventional atmospheric chemical processes and test atmosphere evolution theories.

Hu, Renyu

2015-01-01

381

Fair weather atmospheric electricity  

NASA Astrophysics Data System (ADS)

Not long after Franklin's iconic studies, an atmospheric electric field was discovered in "fair weather" regions, well away from thunderstorms. The origin of the fair weather field was sought by Lord Kelvin, through development of electrostatic instrumentation and early data logging techniques, but was ultimately explained through the global circuit model of C.T.R. Wilson. In Wilson's model, charge exchanged by disturbed weather electrifies the ionosphere, and returns via a small vertical current density in fair weather regions. New insights into the relevance of fair weather atmospheric electricity to terrestrial and planetary atmospheres are now emerging. For example, there is a possible role of the global circuit current density in atmospheric processes, such as cloud formation. Beyond natural atmospheric processes, a novel practical application is the use of early atmospheric electrostatic investigations to provide quantitative information on past urban air pollution.

Harrison, R. G.

2011-06-01

382

Atmospheric Electricity on Mars  

NASA Astrophysics Data System (ADS)

The atmosphere of Mars is one compelling example in our solar system that should possess active electrical processes, where dust storms are known to occur on local, regional, and global scales. Laboratory experiments and simulations all indicate that these events are expected to generate substantial quasi-static electric fields via triboelectric (i.e., frictional) charging, perhaps up to the breakdown potential of the Martian atmosphere. However current observations of potential electrical activity on Mars from both ground-based and orbital platforms have yielded conflicting results. If present, significant atmospheric electricity could be an important source of atmospheric chemistry on Mars, and thus impact our understanding of the evolution of the atmosphere and its past or present astrobiological potential. Here we review the current state of understanding regarding atmospheric electricity on Mars, and discuss its implications pending the results of future measurements.

Delory, G.; Farrell, W.

2011-10-01

383

Global Atmospheric Aerosol Modeling  

NASA Technical Reports Server (NTRS)

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.

Hendricks, Johannes; Aquila, Valentina; Righi, Mattia

2012-01-01

384

Nucleation in the atmosphere  

NASA Astrophysics Data System (ADS)

Small particles play major roles in modulating radiative and hydrological fluxes in the atmosphere and thus they impact both climate (IPCC 2007) and weather. Most atmospheric particles outside clouds are created in situ through nucleation from gas phase precursors and most ice particles within clouds are formed by nucleation, usually from the liquid. Thus, the nucleation process is of great significance in the Earth's atmosphere. The theoretical examination of nucleation in the atmosphere has been based mostly on classical nucleation theory. While diagnostically very useful, the prognostic skill demonstrated by this approach has been marginal. Microscopic approaches such as molecular dynamics and density functional theory have also proven useful in elucidating various aspects of the process but are not yet sufficiently refined to offer a significant prognostic advantage to the classical approach, due primarily to the heteromolecular nature of atmospheric nucleation. An important aspect of the nucleation process in the atmosphere is that the degree of metastability of the parent phase for the nucleation is modulated by a number of atmospheric processes such as condensation onto pre-existing particles, updraft velocities that are the main driving force for supersaturation of water (a major factor in all atmospheric nucleation), and photochemical production rates of nucleation precursors. Hence, atmospheric nucleation is both temporally and spatially inhomogeneous.

Hegg, D. A.; Baker, M. B.

2009-05-01

385

Interactive atmosphere lab  

NSDL National Science Digital Library

The ozone layer makes up an important part of our atmosphere. This informational activity, part of an interactive laboratory series for grades 8-12, explores changes in ozone concentration with altitude. Students view a diagram that shows the layers of the atmosphere with a temperature scale running from the surface of the Earth to the outermost reaches of the atmosphere. After reading introductory material, students are presented with nine questions about the layers of the atmosphere and interactions with ozone. Copyright 2005 Eisenhower National Clearinghouse

University of Utah. Astrophysics Science Project Integrating Research and Education (ASPIRE)

2003-01-01

386

Volcanism and the atmosphere  

NASA Astrophysics Data System (ADS)

AGU Chapman Conference on Volcanism and the Earth's Atmosphere; Selfoss, Iceland, 10-16 June 2012 Volcanic eruptions release volcanic ash and gases into the atmosphere that alter atmospheric chemistry and climate, and represent a hazard to aviation, particularly for modern jet aircraft. At the AGU Chapman Conference on Volcanism and the Earth's Atmosphere, 124 scientists gathered to discuss the effects of volcanism on the atmosphere at timescales ranging from billions of years, over which volcanic emissions have changed the composition of the atmosphere, to the Icelandic Eyjafjallajökull eruption in 2010, which caused a 10-day-long shutdown of North Atlantic air traffic. This was the third Chapman Conference on Volcanism and the Atmosphere, following those held in Hilo, Hawaii, in 1992 and in Santorini, Greece, in 2002, all of which were organized under the auspices of the Commission on Volcanism and the Earth's Atmosphere of the International Association of Volcanism and Chemistry of the Earth's Interior (IAVCEI) and the International Association for Meteorology and Atmospheric Sciences.

Robock, Alan; Rampino, Michael R.; Thordarson, Thorvaldur; Self, Stephen

2012-12-01

387

Optical features of rocket exhaust products interaction with the upper atmosphere  

NASA Astrophysics Data System (ADS)

The launch of powerful rockets and exhaust of space-vehicle engines are accompanied by injection of combustion products with complex structure into the atmosphere. These products contain both gas and dispersed solid components that result in development of gas-dust clouds having certain geometric and dynamic features. The development of such artificial formations in the upper atmosphere is accompanied by rather unusual optical phenomena caused by the scattering of sunlight from the combustion products as well as their interaction with constituents of the upper atmosphere. Investigation of these optical phenomena permits studies of anthropogenic pollution of near-Earth space, interaction processes of pollution with the environment and dynamic processes in the upper atmosphere. The report demonstrates and evaluates experimental data obtained by all-sky photo and TV cameras and by spectral camera S-180-S in the North of Russia.

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

2005-08-01

388

NUMERICAL STUDY OF DEFROSTING PHENOMENA OF AUTOMOTIVE WINDSHIELD GLASS  

Microsoft Academic Search

The present work was undertaken to analyze numerically the defrosting phenomena of automobile windshield glass. In order to analyze the phase change from frost to water on windshield glass by discharging hot air from a defroster nozzle, the flow and the temperature field of the cabin interior, the heat transfer through the windshield glass, and the phase change of frost

W. G. Park; M. S. Park; Y. R. Jung; K. L. Jang

2005-01-01

389

MODELING COUPLED FLUID FLOW AND GEOMECHANICAL AND GEOPHYSICAL PHENOMENA WITHIN  

E-print Network

finite element software package. Several representative numerical simulations are presented to illustrateMODELING COUPLED FLUID FLOW AND GEOMECHANICAL AND GEOPHYSICAL PHENOMENA WITHIN A FINITE ELEMENT FRAMEWORK by Matthew M. Silbernagel #12;#12;iii ABSTRACT A fully coupled finite-element approach is taken

390

The Effects of Globalization Phenomena on Educational Concepts  

ERIC Educational Resources Information Center

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…

Schrottner, Barbara Theresia

2010-01-01

391

Nuclear phenomena in low-energy nuclear reaction research  

NASA Astrophysics Data System (ADS)

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.

Krivit, Steven B.

2013-09-01

392

Nuclear phenomena in low-energy nuclear reaction research.  

PubMed

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

Krivit, Steven B

2013-09-01

393

Beyond a Dichotomic Approach, the Case of Colour Phenomena  

ERIC Educational Resources Information Center

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…

Viennot, L.; de Hosson, C.

2012-01-01

394

The Role of Linguistic Phenomena in Retrieval Performance.  

ERIC Educational Resources Information Center

This progress report presents findings from a failure analysis of two full-text computer-assisted legal research systems, Lexis and Westlaw. Linguistic analyses of unretrieved documents and false drops are discussed, and examples of natural language phenomena that affect Boolean retrieval system performance are examined. (Author/LRW)

Gillaspie, Deborah L.

1995-01-01

395

Discussion about sliding mode algorithms, Zeno phenomena and observability  

E-print Network

the relations between first and high order sliding mode algorithms and both types of Zeno (Chattering and Gen on this mani- fold by means of permanent switches at an infinite frequency between two system structures. Commutations at infinite frequency between two subsystems is named as Zeno1 phenomena in the hybrid dynamical

Paris-Sud XI, Université de

396

Partial discharges in solid dielectrics and corona discharge phenomena  

Microsoft Academic Search

By using techniques developed by many workers to study streamer mechanism in air between metallic electrodes, the phenomena of partial discharges in insulating walls were studied. It is shown that the luminous evolution of partial discharges consisted of the development of a primary and a secondary streamer, for positive pulses. The velocity of propagation of the primary streamer was about

C. Mayoux; M. Goldman

1973-01-01

397

A model for transfer phenomena in structured populations  

E-print Network

, CIRM Luminy, France, June 19, 2008 Peter Hinow et al. Transfer phenomena #12;Overview of the talk therapy, oncolytic viruses . . . combinations of these Chemotherapy is the treatment of choice for 50 of multidrug resistance (MDR) minimizes the effectiveness of such therapy in a large number of patients. Peter

Hinow, Peter

398

Investigation of Transient Phenomena of Proton Exchange Membrane Fuel Cells  

E-print Network

Investigation of Transient Phenomena of Proton Exchange Membrane Fuel Cells by Roongrojana of Proton Exchange Membrane Fuel Cells by Roongrojana Songprakorp BSc, Prince of Songkhla University to the modeling and under- standing of the dynamic behavior of proton exchange membrane fuel cells (PEMFCs

Victoria, University of

399

Chemical Soil Physics Phenomena for Chemical Sensing of Buried UXO  

Microsoft Academic Search

Technology development efforts are under way to apply chemical sensors to discriminate inert ordnance and clutter from live munitions that remain a threat to reutilization of military ranges. However, the chemical signature is affected by multiple environmental phenomena that can enhance or reduce its presence and transport behavior, and can affect the distribution of the chemical signature in the environment.

James Phelan; Stephen W. Webb

1999-01-01

400

Pinning phenomena in the GinzburgLandau Model of Superconductivity  

E-print Network

Pinning phenomena in the Ginzburg­Landau Model of Superconductivity Amandine Aftalion Laboratoire d a homogenized medium in the material. 1 #12; I Introduction Superconducting materials have the property of expelling an applied magnetic field. In fact, the behaviour of a superconducting sample varies according

Serfaty, Sylvia

401

Development of Understanding of Selected Science Phenomena in Young Children.  

ERIC Educational Resources Information Center

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…

Donaldson, Marcia Jackson

402

Fundamental phenomena of quantum mechanics explored with neutron interferometers  

E-print Network

Ongoing fascination with quantum mechanics keeps driving the development of the wide field of quantum-optics, including its neutron-optics branch. Application of neutron-optical methods and, especially, neutron interferometry and polarimetry has a long-standing tradition for experimental investigations of fundamental quantum phenomena. We give an overview of related experimental efforts made in recent years.

J. Klepp; S. Sponar; Y. Hasegawa

2014-07-11

403

Electromagnetically and Thermally Driven Flow Phenomena in Electroslag Welding  

E-print Network

. Electroslag welding has been shown to produce rela- tively defect-free joints at fast deposition rates, with, that the size and shape of the weld pool are the controlling factors in the production of sound welds. While) Electromagnetically and Thermally Driven Flow Phenomena in Electroslag Welding A. H. DILAWARI, J

Eagar, Thomas W.

404

Natural phenomena risk assessment at Rocky Flats Plant  

SciTech Connect

A realistic approach is currently being used at the Rocky Flats Plant to assess the risks of natural phenomena events. The methodology addresses frequency of occurrence estimates, damage stress on the facility and vital equipment, material-at-risk, release fractions and source terms, leakpath, dispersion and dosimetric models, risk curves, and an uncertainty analysis. 28 refs.

Foppe, T.L.

1985-01-01

405

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

PubMed Central

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

Thagard, Paul; Wood, Joanne V.

2015-01-01

406

Search for Resonance Phenomena in SILICON28 + SILICON28 Reactions  

Microsoft Academic Search

('28)Si + ('28)Si reactions have been studied in a search for resonance phenomena similar to those observed in reactions involving lighter nuclei, especially lighter alpha-particle nuclei. Charged particle detection of the evaporation residues at a fixed laboratory angle provides weak evidence for the existence of small (2%) structures in the fusion excitation function. Measurements of the characteristic gamma rays of

Stephanie Beth Dicenzo

1980-01-01

407

Investigations of Basic Ablation Phenomena During Laser Thrombolysis  

Microsoft Academic Search

This paper presents studies of microsecond ablation phenomena that take place during during laser thrombolysis. The main goals were to optimize laser parameters for e-cient 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

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

408

Binding Phenomena within a Reductionist Theory of Grammatical Dependencies  

ERIC Educational Resources Information Center

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…

Drummond, Alex

2011-01-01

409

Discrimination of geophysical phenomena in satellite radar interferograms  

Microsoft Academic Search

Various geophysical phenomena are recorded in the interference patterns formed by differencing two synthetic aperture radar (SAR) images. The fringes generated by the topographic relief can be removed using a digital elevation model (DEM). The remaining fringes map the change in satellite-to-ground range which occurred between the acquisition times of the two images. By comparing different pairs of images spanning

Didier Massonnet; Kurt L. Feigl

1995-01-01

410

DESCRIBING LOW LEVEL PSYCHOLOGICAL PHENOMENA THROUGH CELL ASSEMBLIES  

E-print Network

, there might be a line detector or a `cuteness' detector. 2.1 Why are Cell Assemblies Important It is widelyDESCRIBING LOW LEVEL PSYCHOLOGICAL PHENOMENA THROUGH CELL ASSEMBLIES CHRISTIAN R. HUYCK Middlesex University The Burroughs Hendon, London NW4 4BT, UK E­mail: c.huyck@mdx.ac.uk This paper describes how Cell

Huyck, Chris

411

SELF-PERCEPTION: AN ALTERNATIVE INTERPRETATION OF COGNITIVE DISSONANCE PHENOMENA  

Microsoft Academic Search

A THEORY OF SELF-PERCEPTION IS PROPOSED TO PROVIDE AN ALTERNATIVE INTERPRETATION FOR SEVERAL OF THE MAJOR PHENOMENA EMBRACED BY FESTINGER'S THEORY OF COGNITIVE DISSONANCE AND TO EXPLICATE SOME OF THE SECONDARY PATTERNS OF DATA THAT HAVE APPEARED IN DISSONANCE EXPERIMENTS. IT IS SUGGESTED THAT THE ATTITUDE STATEMENTS WHICH COMPRISE THE MAJOR DEPENDENT VARIABLES IN DISSONANCE EXPERIMENTS MAY BE REGARDED AS

DARYL J. BEM

1967-01-01

412

Cooperative and concentrative phenomena of swimming micro-organisms  

Microsoft Academic Search

This paper describes linear and co-operative phenomena based on the dynamics of the trajectories of swimming cells. The swimming direction of algal cells can be guided so as to focus the cells into a concentrated beam. This directed locomotion, or taxis, results from the orientation of the cells' axes by compensating gravitational and viscous torques. It is named gyrotaxis because

John O. Kessler

1985-01-01

413

Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions  

E-print Network

Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions SANUM Conference (UMN) Eduard Siebrits (SLB) #12;2 Outline · Examples of hydraulic fractures · Governing equations well stimulation Fracturing Fluid Proppant #12;5 Quarries #12;6 Magma flow Tarkastad #12;7 Model EQ 1

Peirce, Anthony

414

Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions  

E-print Network

Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions CSIRO CSS TCP Detournay (UMN) Eduard Siebrits (SLB) #12;2 Outline · Examples of hydraulic fractures · Governing equations well stimulation Fracturing Fluid Proppant #12;5 Quarries #12;6 Magma flow Tarkastad #12;7 Model EQ 1

Peirce, Anthony

415

Single heartbeat cardiac tagging for the evaluation of transient phenomena  

Microsoft Academic Search

Many cardiac abnormalities are of a transient nature, creating a beat-to-beat variation in myocardial function. This work pre- sents the cardiac imaging technique for the measurement of regional function during transient cardiac phenomena. All infor- mation necessary for the reconstruction of a cine loop is ac- quired within a single heartbeat, avoiding the temporal blurring introduced by segmented imaging due

Daniel A. Herzka; J. Andrew Derbyshire; Peter Kellman; Elliot R. McVeigh

2005-01-01

416

Time dependent crack tip phenomena in gas turbine disk alloys  

Microsoft Academic Search

In the continuous quest for improved thrust-to-weight ratio and higher efficiency and power output, designers of aircraft engines and land based power systems subject gas turbine alloys to increasing service temperatures and stresses in aggressive environments. Under these conditions, the determination of component life increasingly requires a detailed understanding of time dependent crack tip phenomena and their ability to degrade

Paul Frederick Browning

1998-01-01

417

Coastal Sand Dune Plant Ecology: Field Phenomena and Interpretation  

ERIC Educational Resources Information Center

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…

McDonald, K.

1973-01-01

418

Many-body phenomena in QED-cavity arrays [Invited  

SciTech Connect

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.

Tomadin, A. [Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck (Austria); Fazio, Rosario [NEST, Scuola Normale Superiore and INFM-CNR, Piazza dei Cavalieri 7, I-56126 Pisa (Italy)

2010-06-15

419

North Atlantic climate variability: phenomena, impacts and mechanisms  

Microsoft Academic Search

Variability of the North Atlantic Oscillation and the Tropical Atlantic dominate the climate of the North Atlantic sector, the underlying ocean and surrounding continents on interannual to decadal time scales. Here we review these phenomena, their climatic impacts and our present state of understanding of their underlying cause.

John Marshall; Yochanan Kushnir; David Battisti; Ping Chang; Arnaud Czaja; Robert Dickson; James Hurrell; Michael McCartney; R. Saravanan; Martin Visbeck

2001-01-01

420

Geosimulation: object-based modeling of urban phenomena  

E-print Network

Editorial Geosimulation: object-based modeling of urban phenomena 1. Introduction Urban simulation an ``evolutionary'' phase, which has spanned the last two decades. A ``new wave'' of urban models have begun to take as collectives of numer- ous elements acting in the city. These ``new wave'' urban models are more likely

Tesfatsion, Leigh

421

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

ERIC Educational Resources Information Center

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…

Barnitz, John G.

422

Developing Critical Thinking through the Study of Paranormal Phenomena.  

ERIC Educational Resources Information Center

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…

Wesp, Richard; Montgomery, Kathleen

1998-01-01

423

MATERIALS, INTERFACES, AND ELECTROCHEMICAL PHENOMENA Hydrophilic Zeolite Coatings for Improved  

E-print Network

MATERIALS, INTERFACES, AND ELECTROCHEMICAL PHENOMENA Hydrophilic Zeolite Coatings for Improved Heat on the surface of a bare, ZSM-5 coated, and Zeolite-A coated stainless steel 304 substrate at different initial surface temperatures was experimentally studied. ZSM-5 and Zeolite-A coated SS-304 are more much more

Aguilar, Guillermo

424

Bacteria, Biofilms and Fluid Dynamics: Elementary Flows and Unexpected Phenomena  

E-print Network

Bacteria, Biofilms and Fluid Dynamics: Elementary Flows and Unexpected Phenomena Wednesday February the migration of bacteria along surfaces when exposed to a shear flow. In particular, we identify an unusual response where flow produces a directed motion of twitching bacteria in the upstream direction. (ii) We

Fisher, Frank

425

Advanced studies on Simulation Methodologies for very Complicated Fracture Phenomena  

NASA Astrophysics Data System (ADS)

Although nowadays, computational techniques are well developed, for Extremely Complicated Fracture Phenomena, they are still very difficult to simulate, for general engineers, researchers. To overcome many difficulties in those simulations, we have developed not only Simulation Methodologies but also theoretical basis and concepts. We sometimes observe extremely complicated fracture patterns, especially in dynamic fracture phenomena such as dynamic crack branching, kinking, curving, etc. For examples, although the humankind, from primitive men to modern scientists such as Albert Einstein had watched the post-mortem patterns of dynamic crack branching, the governing condition for the onset of the phenomena had been unsolved until our experimental study. From in these studies, we found the governing condition of dynamic crack bifurcation, as follows. When the total energy flux per unit time into a propagating crack tip reaches the material crack resistance, the crack braches into two cracks [total energy flux criterion]. The crack branches many times whenever the criterion is satisfied. Furthermore, the complexities also arise due to their time-dependence and/or their-deformation dependence. In order to make it possible to simulate such extremely complicated fracture phenomena, we developed many original advanced computational methods and technologies. These are (i)moving finite element method based on Delaunay automatic triangulation (MFEMBOAT), path independent,(ii) equivalent domain integral expression of the dynamic J integral associated with a continuous auxiliary function,(iii) Mixed phase path-prediction mode simulation, (iv) implicit path prediction criterion. In this paper, these advanced computational methods are thoroughly explained together with successful comparison with the experimental results. Since multiple dynamic crack branching phenomena may be most complicated fracture due to complicated fracture paths, and its time dependence (transient), this simulation and numerical results are mainly explained.

Nishioka, Toshihisa

2010-06-01

426

Seasonality of alcohol-related phenomena in Estonia  

NASA Astrophysics Data System (ADS)

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.

Silm, Siiri; Ahas, Rein

2005-03-01

427

Surface Ocean-Lower Atmosphere Studies: SOLAS  

NASA Astrophysics Data System (ADS)

The US Surface Ocean - Lower Atmosphere Study (US SOLAS) is a component of an international program (SOLAS) with an overall goal: to achieve a quantitative understanding of the key biogeochemical-physical interactions between the ocean and atmosphere, and of how this coupled system affects and is affected by climateand environmental change. There is increasing evidence that the biogeochemical cycles containing the building blocks of life such as carbon, nitrogen, and sulfur have been perturbed. These changes result in appreciable impacts and feedbacks in the SOLA region. The exact nature of the impacts and feedbacks are poorly constrained because of sparse observations, in particular relating to the connectivity and interrelationships between the major biogeochemical cycles and their interaction with physical forcing. It is in these areas that the research and the interdisciplinary research approaches advocated in US SOLAS will provide high returns. The research in US SOLAS will be heavily focused on process studies of the natural variability of key processes, anthropogenic perturbation of the processes, and the positive and negative feedbacks the processes will have on the biogeochemical cycles in the SOLA region. A major objective is to integrate the process study findings with the results from large-scale observations and with small and large- scale modeling and remote sensing efforts to improve our mechanistic understanding of large scale biogeochemical and physical phenomena and feedbacks. US SOLAS held an open workshop in May 2001 to lay the groundwork for the SOLAS program in the United States. Resulting highlights and issues will be summarized around 4 major themes: (1) Boundary-layer Physics, (2) Dynamics of long-lived climate relevant compounds, (3) Dynamics of short-lived climate relevant compounds, and (4) Atmospheric effects on marine biogeochemical processes. Comprehensive reports from the working groups of U.S. SOLAS, and the international science plan which served as overall guidance, can be found at We will explore possible dedicated, interdisciplinary ocean-atmosphere projects as examples of the critical interconnectivity of atmospheric, interfacial, and upper ocean processes to study phenomena of critical importance in understanding the earth's system.

Wanninkhof, R.; Dickerson, R.; Barber, R.; Capone, D. G.; Duce, R.; Erickson, D.; Keene, W. C.; Lenschow, D.; Matrai, P. A.; McGillis, W.; McGillicuddy, D.; Penner, J.; Pszenny, A.

2002-05-01

428

Standard model atmospheres for A-type stars and non-LTE effects  

NASA Astrophysics Data System (ADS)

Analyzing the long-term evolution of active regions (ARs) permits to quantify the link between their atmospheric emission (from optical to X-rays) and the magnetic field. Multi-wavelength studies provide the full story, and not just a snapshot, of the phenomena and they allow us analyze how the atmosphere changes as the field strength decreases (with the dispersion of the AR).

Kubát, Jirí; Korcáková, Daniela

2004-12-01

429

Atmospheric circulation climate changes  

Microsoft Academic Search

The role of the atmospheric circulation in climate change is examined. A review is given of the information available in the past record on the atmosheric circulation and its role in climate change, firstly at the surface via sea level pressure in both the northern and southern hemispheres and secondly for the free atmosphere. As with most climate information, the

Kevin E. Trenberth

1995-01-01

430

Atmosphere and Ocean  

NSDL National Science Digital Library

This site contains 23 questions on the topic of atmosphere and oceans, which covers tides, currents, layers of the atmosphere (troposphere, stratosphere, mesosphere, thermosphere, exosphere) and weather. This is part of the Principles of Earth Science course at the University of South Dakota. Users submit their answers and are provided immediate feedback.

Timothy Heaton

431

Atmosphere Composition Model  

NSDL National Science Digital Library

In this activity, learners create a model using metric measuring tapes and atmosphere composition data. Learners will investigate the major components of the atmosphere (nitrogen and oxygen) as well as the minor components which raise questions about global warming and greenhouse gases.

Lori Lambertson

2007-01-01

432

The Earth's Atmosphere  

NSDL National Science Digital Library

This site contains 12 questions on the topic of the atmosphere, which covers electromagnetic radiation and layers of the Earth's atmosphere (exosphere, thermosphere, and more). This is part of the Principles of Earth Science course at the University of South Dakota. Users submit an answer and are provided immediate verification.

Timothy Heaton

433

Stacking up the Atmosphere  

NSDL National Science Digital Library

In this hands-on activity, participants learn the characteristics of the five layers of the atmosphere and make illustrations to represent them. They roll the drawings and place them in clear plastic cylinders, and then stack the cylinders to make a model column of the atmosphere.

Betsy Youngman

434

Oceanography and Atmospheric Sciences  

E-print Network

Oceanography and Atmospheric Sciences 1959­2009 WayneBurt. #12;Oceanography and Atmospheric in Oceanography (TENOC). Wayne Burt immediately responds with proposal to President Strand of Oregon State College to start a graduate Department of Oceanography. 1959 Oregon State Board of Higher Education approves

435

Geochemical cycles of atmospheric gases  

NASA Technical Reports Server (NTRS)

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.

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

1988-01-01

436

Introduction to Atmospheric Chemistry  

NASA Astrophysics Data System (ADS)

In thirty years of university teaching, Peter Hobbs of the Atmospheric Sciences Department at the University of Washington, has seen atmospheric chemistry grow from a relatively small branch of geosciences into one with which every student of atmospheric sciences needs familiarity Some students are captivated in their first course and make atmospheric chemistry a field of further study or a lifelong career. At the same time, courses of “global change” and emerging curricula in scientific policy require students from diverse backgrounds to develop sufficient knowledge to become well-informed policy-makers. A number of practicing atmospheric chemists are retrained on the job from other scientific backgrounds and need selfeducation in the basics of the field.

Thompson, Anne M.

437

The atmosphere below. (Videotape)  

SciTech Connect

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.

NONE

1992-12-31

438

Atmospheric Fluorescence Yield  

NASA Technical Reports Server (NTRS)

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.

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

439

Earth's Atmosphere Wind Dance  

NSDL National Science Digital Library

This lesson introduces the expanding and condensing properties of air masses and the unequal heating of Earth as the force behind the wind, it also displays the structure of the earth's atmosphere and the science concepts of layering, air density, and particles by using dance concepts such as level and shape. Students use previously learned movement skills to relay information about winds and the structure of the atmosphere. Hello Students! In class we have been learning about the atmosphere, to review some of what we've learned please follow the directions below! To read about the five layers that make up the earth's atmosphere click on this link: 5 Layers of the Atmosphere To learn about the properties of wind click on this link: Wind To learn ...

Miss Magnuson

2009-12-07

440

Modelling extrasolar planetary atmospheres  

NASA Astrophysics Data System (ADS)

The atmospheres of close-in Extrasolar Giant Planets (EGPs) experience important stellar radiation, raising the question of the heat redistribution around the planetary surface and of the importance of photochemistry effects for their spectral properties. They experience mass loss via quasi-thermal escape of their lightest elements. They rotate and experience tidal effects. Model atmospheres struggle to include even part of this complexity. Some address the dynamics of the atmospheres as a whole (3D) as subjected to rotation, or as patches of the surface (wind studies), compromising on the details of the composition and radiative/convective properties. Others solve the composition and radiative/convective properties, compromising on dynamical effects such as rotation. In this paper, we review existing model atmospheres for EGPs, and present the first high spatial resolution local (as opposed to global) 2/3D radiation hydrodynamic simulations of EGP atmospheres including dust cloud formation.

Allard, France

2010-11-01

441

Search for Periodic Trends in Saturn's Atmosphere  

NASA Astrophysics Data System (ADS)

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 fully understood. Additionally, variations of Saturn's radiance at 5.2 microns, a spectral region that is dominated by thermal emisison in an atmospheric window containing only weak gaseous absorption, contain a strong axisymmetric component as well as large discrete features at low and mid-latitutdes that are several degrees colder than the planetary average and uncorrelated with features at shorter wavelengths that are dominated by reflected sunlight. The characterization of several fundamental atmospheric properties and processes 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? What is the tropospheric cloud inventory? What is the relation between the fine-scale cloud structure identified at 5 microns and the distribution of condensates, such as ammonia? 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

Yanamandra-Fisher, Padma

2012-07-01

442

Atmospheric Dispersion Lecture Atmospheric Local-Scale Dispersion Modelling.  

E-print Network

pressure centers (its the opposite on the #12;Southern Hemisphere.) Atmospheric boundary layer The Atmospheric Boundary Layer (ABL) may be characterized, as the part of the atmosphere, which is in closeAtmospheric Dispersion Lecture Atmospheric Local-Scale Dispersion Modelling. Lecturer: Dr Torben

443

Characteristics of aerosol at a lower atmospheric layer in DRAGON field campaign  

NASA Astrophysics Data System (ADS)

Air pollution arises severely over East Asia with the rapid economic development nowadays. Monitoring the atmospheric environment, as one of the purposes, an intensive field campaign, Distributed Regional Aerosol Gridded Observation Networks (DRAGON), was carried out in the spring of year 2012, led by National Aeronautics and Space Administration (NASA). At that time, atmospheric phenomena such as Yellow sand and haze events were observed at Nara in the western part of Japan, as one of the DRAGON observation sites. The atmospheric events were characterized with the AErosol RObotic NETwork (AERONET) data. As a result of the data analysis, it was found that more light-absorbing and smaller particles dominated at the lower than upper atmospheric layer for the Kosa event in particular. A backward trajectory analysis suggested that the Yellow sand event traveled over the East Asian industrial cities, which could lead to a mixture of sand and air pollutants with moderate particle size and light-absorptivity. In addition, visibility observation was evaluated quantitatively with AERONET data in the DRAGON campaign since eye observation was inherently semi-quantitative. The extinction coefficient estimated from visibility was compared to that from AERONET. As a result, it was found that the extinction coefficients were generally consistent to each other. But there were some discrepancies, which could be caused with the atmospheric phenomena or aerosol types. It is confirmed that visibility is strongly influenced with aerosols in the case of severe atmospheric phenomena in particular.

KUJI, M.; Azuma, Y.; Kitakoga, S.; Sano, I.; Holben, B. N.

2013-12-01

444

Seasonal-scale Observational Data Analysis and Atmospheric Phenomenology for the Cold Land Processes Experiment  

NASA Technical Reports Server (NTRS)

The Cold Land Processes Experiment (CLPX) experiment emphasized the development of a strong synergism between process-oriented understanding, land surface models and microwave remote sensing. Our work sought to investigate which topographically- generated atmospheric phenomena are most relevant to the CLPX MSA's for the purpose of evaluating their climatic importance to net local moisture fluxes and snow transport through the use of high-resolution data assimilation/atmospheric numerical modeling techniques. Our task was to create three long-term, scientific quality atmospheric datasets for quantitative analysis (for all CLPX researchers) and provide a summary of the meteorologically-relevant phenomena of the three MSAs (see Figure) over northern Colorado. Our efforts required the ingest of a variety of CLPX datasets and the execution an atmospheric and land surface data assimilation system based on the Navier-Stokes equations (the Local Analysis and Prediction System, LAPS, and an atmospheric numerical weather prediction model, as required) at topographically- relevant grid spacing (approx. 500 m). The resulting dataset will be analyzed by the CLPX community as a part of their larger research goals to determine the relative influence of various atmospheric phenomena on processes relevant to CLPX scientific goals.

Poulos, Gregory S.; Stamus, Peter A.; Snook, John S.

2005-01-01

445

Reference Atmosphere for Mercury  

NASA Technical Reports Server (NTRS)

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.

Killen, Rosemary M.

2002-01-01

446

Atmospheric and adaptive optics  

NASA Astrophysics Data System (ADS)

Atmospheric optics is the study of optical effects induced by the atmosphere on light propagating from distant sources. Of particular concern to astronomers is atmospheric turbulence, which limits the performance of ground-based telescopes. The past two decades have seen remarkable growth in the capabilities and performance of adaptive optics (AO) systems. These opto-mechanical systems actively compensate for the blurring effect of the Earth's turbulent atmosphere. By sensing, and correcting, wavefront distortion introduced by atmospheric index-of-refraction variations, AO systems can produce images with resolution approaching the diffraction limit of the telescope at near-infrared wavelengths. This review highlights the physical processes and fundamental relations of atmospheric optics that are most relevant to astronomy, and discusses the techniques used to characterize atmospheric turbulence. The fundamentals of AO are then introduced and the many types of advanced AO systems that have been developed are described. The principles of each are outlined, and the performance and limitations are examined. Aspects of photometric and astrometric measurements of AO-corrected images are considered. The paper concludes with a discussion of some of the challenges related to current and future AO systems, particularly those that will equip the next generation of large, ground-based optical and infrared telescopes.

Hickson, Paul

2014-11-01

447

Internal Waves in the Atmosphere from High-Resolution Radar Measurements  

Microsoft Academic Search

A radar sounding system developed by Richter has a height resolution (about I meter) capable of resolving the detailed structure of small features in the atmosphere that were never before seen. Two distinctly different types of wave phenomena characterize many of the records. One type is a long-period internal wave. The mechanism of generation is discussed, and waves observed on

E. E. Gossard; J. H. Richter; D. Atlas

1970-01-01

448

Modelling the Entire Atmosphere of Betelgeuse with 3D Simulations Bernd Freytag & Michelle MizunoWiedner  

E-print Network

to a fixed value (3:25 #2; 10 9 erg K 1 g 1 ). This replaces the energy production by nuclear fusion of observational data on Betelgeuse points to a highly dynamical atmosphere with phenomena that have not yet been for Betelgeuse and lies at the lower end of the allowed range in surface gravity. Analysis We have begun

Freytag, Bernd

449

Exploring NASA and ESA Atmospheric Data Using GIOVANNI, the Online Visualization and Analysis Tool  

NASA Technical Reports Server (NTRS)

Giovanni, the NASA Goddard online visualization and analysis tool (http://giovanni.gsfc.nasa.gov) allows users explore various atmospheric phenomena without learning remote sensing data formats and downloading voluminous data. Using NASA MODIS (Terra and Aqua) and ESA MERIS (ENVISAT) aerosol data as an example, we demonstrate Giovanni usage for online multi-sensor remote sensing data comparison and analysis.

Leptoukh, Gregory

2007-01-01

450

Measurements of solar flare enhancements to the single event upset environment in the upper atmosphere [avionics  

Microsoft Academic Search

The Cosmic Radiation Environment Monitor has flown regularly on a supersonic airliner over a period of 18 months in order to explore the extent of single-event phenomena in the upper atmosphere. Data presented are from flights occurring between November 1988 and May 1990. The detector system used is briefly described. Quiet-time data now have good statistical precision and are compared

C. S. Dyer; A. J. Sims; J. Farren; J. Stephen

1990-01-01

451

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 ...

452

Photochemistry of Planetary Atmospheres  

NASA Astrophysics Data System (ADS)

The Space Age started half a century ago. Today, with the completion of a fairly detailed study of the planets of the Solar System, we have begun studying exoplanets (or extrasolar planets). The overriding question in is to ask whether an exoplanet is habitable and harbors life, and if so, what the biosignatures ought to be. This forces us to confront the fundamental question of what controls the composition of an atmosphere. The composition of a planetary atmosphere reflects a balance between thermodynamic equilibrium chemistry (as in the interior of giant planets) and photochemistry (as in the atmosphere of Mars). The terrestrial atmosphere has additional influence from life (biochemistry). The bulk of photochemistry in planetary atmospheres is driven by UV radiation. Photosynthesis may be considered an extension of photochemistry by inventing a molecule (chlorophyll) that can harvest visible light. Perhaps the most remarkable feature of photochemistry is catalytic chemistry, the ability of trace amounts of gases to profoundly affect the composition of the atmosphere. Notable examples include HOx (H, OH and HO2) chemistry on Mars and chlorine chemistry on Earth and Venus. Another remarkable feature of photochemistry is organic synthesis in the outer solar system. The best example is the atmosphere of Titan. Photolysis of methane results in the synthesis of more complex hydrocarbons. The hydrocarbon chemistry inevitably leads to the formation of high molecular weight products, giving rise to aerosols when the ambient atmosphere is cool enough for them to condense. These results are supported by the findings of the recent Cassini mission. Lastly, photochemistry leaves a distinctive isotopic signature that can be used to trace back the evolutionary history of the atmosphere. Examples include nitrogen isotopes on Mars and sulfur isotopes on Earth. Returning to the question of biosignatures on an exoplanet, our Solar System experience tells us to look for speciation that reveals the reaction pathways, disequilibrium forcing (what portion of the irradiance of the central star is harvested?) and isotopic signatures that are fingerprints of photochemistry and biochemistry.

Yung, Y. L.

2005-12-01

453

The Mercury atmosphere  

NASA Technical Reports Server (NTRS)

Data available on the composition of Mercury's atmosphere are reviewed, and the sources of these atmospheric components are considered. The known gaseous components in Mercury's atmosphere are H, He, O, Na, and K; among other gases likely to be present are H2 and H2O. Probable sources of these components are the solar wind for hydrogen and helium. The alkalis and water are considered to come from the evaporation of meteoroidal material, with a possible contribution to the former by sputtering and photosputtering.

Hunten, D. M.; Shemansky, D. E.; Morgan, T. H.

1988-01-01

454

Heterogeneous Atmospheric Chemistry  

NASA Astrophysics Data System (ADS)

In the past few years it has become increasingly clear that heterogeneous, or multiphase, processes play an important role in the atmosphere. Unfortunately the literature on the subject, although now fairly extensive, is still rather dispersed. Furthermore, much of the expertise regarding heterogeneous processes lies in fields not directly related to atmospheric science. Therefore, it seemed desirable to bring together for an exchange of ideas, information, and methodologies the various atmospheric scientists who are actively studying heterogeneous processes as well as other researchers studying similar processes in the context of other fields.

Schryer, David R.

455

Atmospheric Visualization Collection (AVC)  

NSDL National Science Digital Library

The AVC collection provides materials that facilitate research and learning about the atmosphere through visualization of atmospheric data. The collection provides access to an archive of data from the Atmospheric Radiation Measurement (ARM) program's Southern Great Plains (SGP), North Slope of Alaska (NSA), and Tropic West Pacific (TWP) sites. Educational material such as lesson plans and conceptual models based on these data are part of the collection. The data archive focuses on remote sensing related to the effects and interactions of sunlight, radiant energy, clouds, temperature, weather and climate. The collection website is translated into French, German, Japanese, Korean, Italian, Spanish, Chinese and Portuguese.

456

Triton's Distorted Atmosphere  

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

457

Introduction to the Atmosphere  

NSDL National Science Digital Library

This site provides a brief overview of the properties associated with the atmosphere, the thin envelope of air that surrounds our planet and is a mixture of gases, each with its own physical properties. It will help students to recognize that while ninety nine percent of the atmosphere is made up of nitrogen and oxygen, the rest is made up of trace gases that can have a large impact on atmospheric processes. The site serves as a reference for and includes links to seven classroom activities.

458

Video detection and analysis techniques of transient astronomical phenomena  

NASA Technical Reports Server (NTRS)

Low-light-level television systems have been utilized to gain information on meteors, aurorae, and other faint, transient astronomical phenomena. Such phenomena change not only their position as a function of time, but also their photometric and spectral characteristics in as little as 1/60 second, thus requiring unique methods of analysis. Data observed with television systems and recorded on video tape have been analyzed with a system utilizing both analog and digital techniques. Both off-the-shelf equipment and inhouse developments are used to isolate sequences of moving images and to store them in a form suitable for photometric and spectral reduction. Current emphasis of the analysis effort is directed at the measurement of the first-order emission lines of meteor spectra, the results of which will yield important compositional information concerning the nature of the impinging meteoroid.

Clifton, K. S.; Reese, R., Jr.; Davis, C. W.

1979-01-01

459

Nonlinear dynamic phenomena in the space shuttle thermal protection system  

NASA Technical Reports Server (NTRS)

The development of an analysis for examining the nonlinear dynamic phenomena arising in the space shuttle orbiter tile/pad thermal protection system is presented. The tile/pad system consists of ceramic tiles bonded to the aluminum skin of the orbiter through a thin nylon felt pad. The pads are a soft nonlinear material which permits large strains and displays both hysteretic and nonlinear viscous damping. Application of the analysis to a square tile subjected to transverse sinusoidal motion of the orbiter skin is presented and the following nonlinear dynamic phenomena are considered: highly distorted wave forms, amplitude-dependent resonant frequencies which initially decrease and then increase with increasing amplitude of motion, magnification of substrate motion which is higher than would be expected in a similarly highly damped linear system, and classical parametric resonance instability.

Housner, J. M.; Edighoffer, H. H.; Park, K. C.

1981-01-01

460

Charge compensation phenomena for polarization discontinuities in ferroelectric superlattices  

NASA Astrophysics Data System (ADS)

Based on the Landau-Ginzburg theory, the screening charge compensation phenomena for polarization discontinuities at interface in ferroelectric superlattices are investigated. Interface mixing leads to polarization continuity or discontinuity in superlattices. Free charge with equal but of opposite sign for alternate interface, driven by internal electric field, builds up to counteract the depolarization effect in superlattices. The charge density depends on the degree of interface mixing, and it approaches a saturated value when the mismatch of internal field or polarization at interface vanishes. Using PbTiO3/SrTiO3 (PT/ST) as a model system, the charge compensation phenomena for polarization discontinuities in superlattices is investigated by examining the polarization and internal electric field profiles. Dependence of local polarization and internal field at the interfaces on screening charge density is also examined in detail.

Lim, K.-G.; Chew, K.-H.; Wang, D. Y.; Ong, L.-H.; Iwata, M.

2014-12-01

461

An introduction to breakdown phenomena in disordered systems  

NASA Astrophysics Data System (ADS)

The rupture of a medium under stress typifies breakdown phenomena. More generally, the latter encompass the dynamics of systems of many interacting elements governed by the interplay of a driving force with a pinning disorder, resulting in a macroscopic transition. A simple mean-field formalism incorporating these features is presented and applied to systems representative of fracture phenomena, social dilemmas, and magnets out of equilibrium. The similarities and differences in the corresponding mathematical structures are emphasized. The solutions are best obtained from a graphical method, from which very general conclusions may be drawn. In particular, the various classes of disorder distribution are treated without reference to a particular analytical or numerical form, and are found to lead to qualitatively different transitions. Finally, the notion of effective (or phenomenological) theory is introduced and illustrated for nonequilibrium disordered magnets.

da Silveira, Rava

1999-12-01

462

Phenomena associated with magma expansion into a drift  

SciTech Connect

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.

Gaffney, E. S. (Edward S.)

2002-01-01

463

ESM of Ionic and Electrochemical Phenomena on the Nanoscale  

SciTech Connect

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.

Kalinin, Sergei V [ORNL; Kumar, Amit [Pennsylvania State University; Balke, Nina [ORNL; McCorkle, Morgan L [ORNL; Guo, Senli [ORNL; Arruda, Thomas M [ORNL; Jesse, Stephen [ORNL

2011-01-01

464

ESM of Ionic and Electrochemical Phenomena on the Nanoscale  

SciTech Connect

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. 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. 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.

Kalinin, Sergei V. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Kumar, Amit [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Balke, Nina [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); McCorkle, Morgan [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Guo, Senli [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Arruda, Thomas M. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Jesse, Stephen [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

2011-11-01

465

Autoscopic phenomena: case report and review of literature  

PubMed Central

Background Autoscopic phenomena are psychic illusory visual experiences consisting of the perception of the image of one's own body or face within space, either from an internal point of view, as in a mirror or from an external point of view. Descriptions based on phenomenological criteria distinguish six types of autoscopic experiences: autoscopic hallucination, he-autoscopy or heautoscopic proper, feeling of a presence, out of body experience, negative and inner forms of autoscopy. Methods and results We report a case of a patient with he-autoscopic seizures. EEG recordings during the autoscopic experience showed a right parietal epileptic focus. This finding confirms the involvement of the temporo-parietal junction in the abnormal body perception during autoscopic phenomena. We discuss and review previous literature on the topic, as different localization of cortical areas are reported suggesting that out of body experience is generated in the right hemisphere while he-autoscopy involves left hemisphere structures. PMID:21219608

2011-01-01

466

Sixth Microgravity Fluid Physics and Transport Phenomena Conference Abstracts  

NASA Technical Reports Server (NTRS)

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.

Singh, Bhim (Compiler)

2002-01-01

467

The function of nonlinear phenomena in meerkat alarm calls.  

PubMed

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

Townsend, Simon W; Manser, Marta B

2011-02-23

468

Concepts and methods for describing critical phenomena in fluids  

NASA Technical Reports Server (NTRS)

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.

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

1977-01-01

469

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

PubMed

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

Occhionero, Miranda; Cicogna, Piera Carla

2011-12-01

470

Molecular dynamics simulations: insight into molecular phenomena at interfaces.  

PubMed

Molecular dynamics simulations, when aptly devised, can enhance our fundamental understanding of a system, set up a platform for testing theoretical predictions, and provide insight and a framework for further experimental studies. This feature article highlights the importance of molecular dynamics simulations in understanding interfacial phenomena using three case studies involving liquid-liquid and solid-liquid interfaces. After briefly reviewing molecular dynamics methods, we discuss velocity slip at a liquid-liquid interface, the coalescence of liquid drops in suspension and in free space, and the behavior of colloidal nanoparticles at a liquid-liquid interface. We emphasize the utility of simple intermolecular potentials and generic liquids. The case studies exemplify the significant insight gained through the molecular modeling approach regarding the interfacial phenomena studied. We conclude the highlight with a brief discussion illustrating potential shortcomings and pitfalls of molecular dynamics simulations. PMID:24684531

Razavi, Sepideh; Koplik, Joel; Kretzschmar, Ilona

2014-09-30

471

Scaling relations and multicritical phenomena from Functional Renormalization  

E-print Network

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