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1

Critical phenomena in atmospheric precipitation  

E-print Network

LETTERS Critical phenomena in atmospheric precipitation OLE PETERS1,2,3 * AND J. DAVID NEELIN3 1 critical value, an order parameter increases as a power law. At criticality, order-parameter fluctuations and order parameter are coupled, the critical point can become an attractor, and self-organized criticality

Loss, Daniel

2

Atmospheric phenomena before and during sunset  

NASA Astrophysics Data System (ADS)

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

Menat, M.

3

Numerical analysis and modeling of atmospheric phenomena  

NASA Technical Reports Server (NTRS)

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

Stone, Peter H.

1994-01-01

4

Single event phenomena in atmospheric neutron environments  

SciTech Connect

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

Gossett, C.A.; Hughlock, B.W.; Katoozi, M.; LaRue, G.S. (Boeing Defense and Space Group, Seattle, WA (United States)); Wender, S.A. (Los Alamos National Lab., NM (United States))

1993-12-01

5

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

E-print Network

Twilight phenomena in the atmosphere of Venus during the 2004 inferior conjunction Paolo Tanga Laboratoire Cassiopée - Observatoire de la Côte d'Azur #12;Twilight phenomena in the atmosphere of Venus'Azur Abstract - Twilight phenomena of Venus are peculiar aspects visible in proximity of the inferior

Schneider, Glenn

6

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 Nio ...

Finney, William W., III (William Warner)

2014-01-01

7

A review of Titans atmospheric phenomena  

Microsoft Academic Search

Saturns satellite Titan is a particularly interesting body in our solar system. It is the only satellite with a dense atmosphere,\\u000a which is primarily made of nitrogen and methane. It harbours an intricate photochemistry, that populates the atmosphere with\\u000a aerosols, but that should deplete irreversibly the methane. The observation that methane is not depleted led to the study\\u000a of Titans

Mathieu Hirtzig; Tetsuya Tokano; Sbastien Rodriguez; Stphane le Moulic; Christophe Sotin

2009-01-01

8

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

9

Wave phenomena comparison between Mars and Titan upper atmospheres  

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

10

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

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

11

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

PubMed

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

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

2011-12-01

12

The Atmospheric Phenomena Laboratory: Connecting Electrical And Computer Engineering Through Undergraduate Research  

E-print Network

This paper describes the development of software tools for the automation of data collection, processing, display and storage of information for the Atmospheric Phenomena Laboratory at the University of Puerto Rico-Mayagez (UPRM). Undergraduate Electrical and Computer Engineering students have had a key role in the development of hardware and software tools for a lightning location system. Students developed software applications using Oracle, Access, Labview and Visual Basic. These applications completed the prototype network of the lightning location system, which consists of three remote stations, linked through the University of Puerto Rico's computer network. These software tools provide lightning detection and location capabilities that will contribute to the development of an isokeraunic map and a custom model to predict lightning occurrences. Students gained a meaningful research experience in which they learned and applied electrical and computer engineering concepts in the solution of complex software problems.

Efran O' Neill-Carrillo; Session Sc; Javier Arroyo; Jos Rosado; Julio Santiago; Ismael Jimnez

2002-01-01

13

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

NASA Astrophysics Data System (ADS)

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

Starik, Alexander M.

2013-11-01

14

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, Schrter, 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

15

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

16

Analytical Estimate of Atmospheric Newtonian Noise Generated by Acoustic and Turbulent Phenomena in Laser-Interferometric Gravitational Waves Detectors  

E-print Network

We present a theoretical estimate of the atmospheric Newtonian noise due to fluctuations of atmospheric mass densities generated by acoustic and turbulent phenomena and we determine the relevance of such noise in the laser-interferometric detection of gravitational waves. First, we consider the gravitational coupling of interferometer test-masses to fluctuations of atmospheric density due to the propagation of sound waves in a semispace occupied by an ideal fluid delimited by an infinitely rigid plane. We present an analytical expression of the spectrum of acceleration fluctuations of the test-masses of the interferometer in terms of the experimentally obtainable spectrum of pressure fluctuations. Second, we consider the gravitational coupling of interferometer test-masses to fluctuations of atmospheric density due to the propagation of sound waves generated in a turbulent Lighthill process. We present an analytical expression - in the Fourier space - of the spectrum of acceleration fluctuations of the test-masses of the interferometer. Finally, we discuss the relevance of these noise sources in the detection of gravitational waves by comparing the estimated spectral densities of Newtonian atmospheric noises considered here to the expected sensitivity curve of the VIRGO detector.

Carlo Cafaro; S. A. Ali

2009-06-26

17

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

PubMed

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

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

1995-03-01

18

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

Microsoft Academic Search

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

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

2010-01-01

19

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

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 role of heat and mass transfer phenomena in atmospheric freeze-drying of foods in a fluidised bed  

Microsoft Academic Search

Freeze-drying under atmospheric pressure in a fluidised bed of adsorbent fine particles is proposed for dehydrating food products at lower cost than the traditional freeze-drying process under vacuum. The aim of this paper is to evaluate the role of heat and mass transfer coefficients between the product and the bed during the process at atmospheric pressure and to analyse the

P. Di Matteo; G. Dons; G. Ferrari

2003-01-01

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, Bjrn; Strand, Erling

2013-04-01

23

Long-period fading in atmospherics during severe meteorological activity and associated solar geophysical phenomena at low latitudes  

E-print Network

interest in recent years. During the south-west monsoon season (June to September) the rainfall over large) suggested that the earth's magnetic ®eld may in¯uence the behaviour of the lower atmosphere through some the passage of the interplanetary magnetic sector structure (Wilcox and Scherrer, 1979). From the nature

Boyer, Edmond

24

Recreation of Natural Optical Phenomena  

NASA Astrophysics Data System (ADS)

This project was undertaken to study and fully understand optical atmospheric phenomena. Research was done on the structure and formation of colorful atmospheric phenomena including, but not limited to, primary, secondary, and supernumerary rainbows, halos, parhelia, and glories. This study also undertakes an attempt to create some of these phenomena. Using hand-made epoxy crystals for ice, a round bottom flask as a water droplet, and a high-powered halogen lamp for sunlight, primary, secondary, and supernumerary rainbows and halos were created and photographed.

Paonessa, Tiffany; Sheldon, Peter

2009-03-01

25

Fluctuation phenomena  

SciTech Connect

Fluctuation phenomena are the ''tip of the iceberg'' revealing the existence, behind even the most quiescent appearing macroscopic states, of an underlying world of agitated, ever-changing microscopic processes. While the presence of these fluctuations can be ignored in some cases, e.g. if one is satisfied with purely thermostatic description of systems in equilibrium, they are central to the understanding of other phenomena, e.g. the nucleation of a new phase following the quenching of a system into the co-existence region. This volume contains a collection of review articles, written by experts in the field, on the subject of fluctuation phenomena. Some of the articles are of a very general nature discussing the modern mathematical formulation of the problems involved, while other articles deal with specific topics such as kinetics of phase transitions and conductivity in solids. The juxtaposition of the variety of physical situations in which fluctuation phenomena play an important role is novel and should give the reader an insight into this subject.

Montroll, E.W.; Lebowitz, J.L.

1986-01-01

26

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

27

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

28

Crystallization phenomena in slags  

NASA Astrophysics Data System (ADS)

The crystallization of the mold slag affects both the heat transfer and the lubrication between the mold and the strand in continuous casting of steel. In order for mold slag design to become an engineering science rather than an empirical exercise, a fundamental understanding of the melting and solidification behavior of a slag must be developed. Thus it is necessary to be able to quantify the phenomena that occur under the thermal conditions that are found in the mold of a continuous caster. The double hot thermocouple technique (DHTT) and the Confocal Laser Scanning Microscope used in this study are two novel techniques for investigating melting and solidification phenomena of transparent slags. Results from these techniques are useful in defining the phenomena that occur when the slag film infiltrates between the mold and the shell of the casting. TTT diagrams were obtained for various slags and indicated that the onset of crystallization is a function of cooling rate and slag chemistry. Crystal morphology was found to be dependent upon the experimental temperature and four different morphologies were classified based upon the degree of melt undercooling. Continuous cooling experiments were carried out to develop CCT diagrams and it was found that the amount and appearance of the crystalline fraction greatly depends on the cooling conditions. The DHTT can also be used to mimic the cooling profile encountered by the slag in the mold of a continuous caster. In this differential cooling mode (DCT), it was found that the details of the cooling rate determine the actual response of the slag to a thermal gradient and small changes can lead to significantly different results. Crystal growth rates were measured and found to be in the range between 0.11 mum/s to 11.73 mum/s depending on temperature and slag chemistry. Alumina particles were found to be effective innoculants in oxide melts reducing the incubation time for the onset of crystallization and also extending the temperature range of observed crystallization. The effect of changing the gas atmosphere surrounding the sample has been studied. The presence of water vapor increased the nucleation rate and crystal growth rate significantly when compared to experiments carried out in a dry atmosphere. With an atmosphere of Argon and Argon-3% Hydrogen mixture, the incubation time for crystallization was increased with several minutes. The crystal growth rate in these atmospheres was also drastically reduced compared to an atmosphere of normal air. Significant numbers of bubbles were formed during the initial melting of mold slag samples and the melting rate of the slag was found to be related to the rate of bubble generation and to the rate of heat transport.

Orrling, Carl Folke

2000-09-01

29

Phenomena of fault-arc propagation on cables and wires for space applications in vacuum and oxygen-enriched atmosphere and air  

Microsoft Academic Search

Investigations of fault arc propagation on spacecraft cables under spacecraft specific conditions, e.g. vacuum, normal and oxygen enriched atmosphere have been performed. Typical patterns of fault arc extinction have been identified and their consequences with respect to causes of damages are discussed. The results indicate that for a given test current and test voltage the behavior of the arc and

F. R. Frontzek; D. Koenig; M. D. Judd; H. J. Reher

1994-01-01

30

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; Lhr, Hermann

2014-12-01

31

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

32

Remote Sensing of Atmospheric Phenomena Using GPS  

E-print Network

and Chief Scientist Digital Authentication Technologies 4pm, Wed., Oct. 3, 2007 Auditorium of the Center for monitoring and forecasting space weather storms and issuing relevant alerts is limited by our sparse sensing work on weak signal detection techniques. He later joined IBM's Yorktown Heights Research division

Zanibbi, Richard

33

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

34

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

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

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? Borovi?ka; W. Graham Elford; Douglas O. ReVelle; Robert L. Hawkes; Vladimr Porub?an; Milo imek

1998-01-01

37

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

38

Wave Phenomena Simulations  

NSDL National Science Digital Library

This resource contains interactive wave motion simulations for students in introductory physics classes. The various simulations model phenomena such as wave superposition, reflection, and refraction, as well as the interference of waves, the Doppler effect, the superposition of sine waves, and the various intensities of spherical waves.

Taylor, Barney

2003-10-10

39

Transport phenomena in nanofluidics  

Microsoft Academic Search

The transport of fluid in and around nanometer-sized objects with at least one characteristic dimension below 100nm enables the occurrence of phenomena that are impossible at bigger length scales. This research field was only recently termed nanofluidics, but it has deep roots in science and technology. Nanofluidics has experienced considerable growth in recent years, as is confirmed by significant scientific

Reto B. Schoch; Jongyoon Han; Philippe Renaud

2008-01-01

40

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

41

Some nonlinear optical phenomena  

NASA Astrophysics Data System (ADS)

Some nonlinear optical phenomena are investigated, especially stimulated scattering, from the point of view of the kinetic theory of radiation (i.e., photon transport theory). Kinetic theory provides a perspective, different from Maxwell's wave theory, from which an examination of these complex matters may proceed with some advantages: (i) considerable mathematical simplication in some instances, (ii) clear and natural separation of microscopic versus macroscopic nonlinearities, (iii) kinetic theory couples the radition field nonlinearly to a formally exact description of the matter field, and (iv) it is believed that the mathematical model provided by kinetic theory is perhaps better suited for numerical studies of the effect of diverse nonlinear optical phenomena upon laser-fusion implosion dynamics than Maxwell's wave theory. Although the main emphasis is upon stimulated scattering, the incorporation of other nonlinearities into the kinetic model is discussed briefly.

Hammouda, Boualem; Osborn, Richard K.

1981-09-01

42

Lunar transient phenomena  

NASA Astrophysics Data System (ADS)

Lunar transient phenomena (LTP) sightings are classified into five categories: brightenings, darkenings, reddish colorations, bluish colorations, and obscurations. There is evidence that the remaining LTP's are of lunar origin. A substantial number of sightings are independently confirmed. They have been recorded on film and spectrograms, as well as with photoelectric photometers and polarization equipment. It suggested that the LTP's may be gentle outgassings of less-than-volcanic proportions.

Cameron, W. S.

1991-03-01

43

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

44

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

45

Shock wave reflection phenomena  

NASA Astrophysics Data System (ADS)

The present publication encompasses shock-wave reflection phenomena in a review of their phenomenological aspects in a range of flow types. Oblique shock-wave reflections are analyzed by means of expressions from the two- and three-shock theories with illustrations of the transition boundaries from regular and Mach reflection. Shock-wave reflection is further reviewed for such cases as unsteady, steady, and pseudosteady flows with criteria for the formation and termination of these reflection cases. Experimental results are compared to analytical predictions, and the governing equations are treated with additional expressions and modifications that describe viscous and real gas effects. It is expected that the work in this volume can lead to the development of numerical codes for the prediction of regular reflection as well as single- and double-Mach reflection.

Ben-Dor, Gabi

46

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

47

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

Gmez-Ullate, David; Lombardo, Sara; Maas, Manuel; Mazzocco, Marta; Nijhoff, Frank; Sommacal, Matteo

2010-10-01

48

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

49

Teaching undergraduate nurses nursing phenomena.  

PubMed

Nursing phenomena, complex and dynamic conceptual building blocks, are the basis of our nursing language. Students have difficulty understanding what nursing phenomena are and how to link them to practice and research. The authors describe incremental experiential learning strategies that were used to help students learn and apply the basic concepts of their nursing language. PMID:20010266

Hemman, Eileen A; Fought, Sharon Gavin

2010-01-01

50

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.

51

International Workshop on Time-Variable Phenomena in the Jovian System. (Abstract Only),  

National Technical Information Service (NTIS)

Many of the scientifically interesting phenomena that occur in the Jovian system are strongly time variable. Some are episodic (e.g., Io volcanism); some are periodic (wave transport in Jupiter's atmosphere); and some are exceedingly complex (magnetospher...

M. J. S. Belton, R. A. West

1988-01-01

52

Critical velocity phenomena and the LTP. [Lunar Transient Phenomena  

NASA Technical Reports Server (NTRS)

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

Srnka, L. J.

1977-01-01

53

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, Snells laws, focal distances in lenses and mirrors, and diffraction phenomena, which we hope will motivate teachers to implement it in their own classes and schools.

Rodrigues, M.; Simeo Carvalho, P.

2014-11-01

54

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

2007-04-30

55

Spectres of short time atmospheric light phenomena:meteors  

Microsoft Academic Search

The theory of radiation, the methods of processing (spectrophotometry) and the interpretation of the meteors spectra are given. The original observations as well and the processing of the spectrogrammes is discussed in the connection with influx of various elements to the Earth. The problems of the studiing of the meteoric plasma are outlined. The problems of the meteors explosions are

V. A. Smirnov

1994-01-01

56

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

57

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

58

Spectres of short time atmospheric light phenomena:meteors  

NASA Astrophysics Data System (ADS)

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

Smirnov, V. A.

59

Attrition and elutriation phenomena in industrial atmospheric fluidized bed combustors  

SciTech Connect

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

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

1980-01-01

60

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

61

Discovery Potential for New Phenomena  

E-print Network

We examine the ability of future facilities to discover and interpret non-supersymmetric new phenomena. We first explore explicit manifestations of new physics, including extended gauge sectors, leptoquarks, exotic fermions, and technicolor models. We then take a more general approach where new physics only reveals itself through the existence of effective interactions at lower energy scales. [Summary Report of the New Phenomena Working Group. To appear in the Proceedings of the 1996 DPF/DPB Summer Study on New Directions for High Energy Physics - Snowmass96, Snowmass, CO, 25 June - 12 July 1996.

Stephen Godfrey; JoAnne L. Hewett; Lawrence E. Price

1997-04-10

62

Theory of dynamic critical phenomena  

Microsoft Academic Search

An introductory review of the central ideas in the modern theory of dynamic critical phenomena is followed by a more detailed account of recent developments in the field. The concepts of the conventional theory, mode-coupling, scaling, universality, and the renormalization group are introduced and are illustrated in the context of a simple example-the phase separation of a symmetric binary fluid.

P. C. Hohenberg; B. I. Halperin

1977-01-01

63

Discovery potential for new phenomena  

SciTech Connect

The authors examine the ability of future facilities to discover and interpret non-supersymmetric new phenomena. The authors first explore explicit manifestations of new physics, including extended gauge sectors, leptoquarks, exotic fermions, and technicolor models. They then take a more general approach where new physics only reveals itself through the existence of effective interactions at lower energy scales.

Godfrey, S. [Carleton Univ., Ottawa, Ontario (Canada). Ottawa Carleton Inst. for Physics; Hewett, J.L. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Price, L.E. [Argonne National Lab., IL (United States). High Energy Physics Div.

1997-03-01

64

Burst phenomena in solar flares  

Microsoft Academic Search

Solar flares are rapid dissipative processes in which the energy accumulated in the magnetic field is released in the forms of plasma heating, explosive plasma flows with flare shock generations, particle accelerations, and emissions in a very broad range of frequencies ranging from radio waves up to gamma-rays. As solar flares and related phenomena influence not only the processes in

P. Kotrc; Yu. A. Kupryakov; J. Jurck

2002-01-01

65

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

66

URANIUM PYROPHORICITY PHENOMENA AND PREDICTION  

Microsoft Academic Search

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

Martin G. Plys; Michael Epstein; Boro Malinovic

67

Affective phenomena - descriptive and theoretical  

Microsoft Academic Search

Reviews the work of 15 researchers (1910-1911), in the field of affective phenomena. The topics covered include a critical review of work in the field of affective psychology in the past 10 years, the theory of pleasure, the theory of empirical \\

H. N. Gardiner

1911-01-01

68

Transport phenomena in material processing  

Microsoft Academic Search

Research activity related to material processing and manufacturing has been substantially increased in recent years. This increase is largely motivated by the growing sophistication in the nature of modern processes and the continuing quest for better productivity and less cost in the industry. Researchers in the heat transfer community have contributed significantly to gaining fundamental understanding of the transport phenomena

M. Charmichi; M. K. Chyu; Y. Joshi; S. M. Walsh

1990-01-01

69

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

70

Visible Earth: Atmosphere  

NSDL National Science Digital Library

This site is part of Visible Earth, which is hosted by the National Aeronautics and Space Administration (NASA), and contains a searchable directory of images, visualizations, and animations of the Earth. This section contains images of the Earth's atmosphere, which includes aerosols, air quality, atmospheric phenomena, pressure, radiation, temperature, water, winds, clouds, precipitation, and earth's radiation bidget. Each image is available in a variety of resolutions and sizes, with a brief description, credit, date, and the name of the spacecraft or instrument that captured the image.

71

Accretion Disks and Eruptive Phenomena  

E-print Network

This paper describes eruptive phenomena in pre-main sequence stars. The eruptions of FU Orionis stars have much in common with outbursts in other accreting systems, such as dwarf novae and some symbiotic stars. These common features are best understood as increases in the rate material flows through an accretion disk. The spectroscopic properties, decay of the light curves, and outflow phenomena suggest that these outbursts arise from thermal instabilities in the disk. Available data and estimates for recurrence times indicate that young stars can accrete much, perhaps all, of their mass in FU Ori accretion events. Future observations can test this notion and place better constraints on the importance of eruptive events in the early life of a low mass star.

Scott J. Kenyon

1999-04-02

72

Statistical phenomena in particle beams  

SciTech Connect

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

Bisognano, J.J.

1984-09-01

73

Dynamic critical phenomena in fractals  

NASA Astrophysics Data System (ADS)

Dynamic critical phenomena are investigated, via the spin-flip kinetic Ising model, on two finitely ramified fractals: the Sierpinski gasket (SG) and the Koch curve. We show, using the Kawasaki inequality, that the dynamic critical exponent of the SG satisfies z>=df, the lower bound forming the conventional value. We also formulate a lower bound for the characteristic decay time. For the Koch curve we show exactly that z=2df=dw, where dw is the random-walk dimension.

Luscombe, James H.; Desai, Rashmi C.

1985-07-01

74

Coherent phenomena in photonic crystals  

Microsoft Academic Search

We study the spontaneous emission, the absorption and dispersion properties\\u000aof a ${\\\\bf \\\\Lambda}$-type atom where one transition interacts near resonantly\\u000awith a double-band photonic crystal. Assuming an isotropic dispersion relation\\u000anear the band edges, we show that two distinct coherent phenomena can occur.\\u000aFirst, the spontaneous emission spectrum of the adjacent free space transition\\u000aobtains `dark lines' (zeroes in

D. G. Angelakis; E. Paspalakis; P. L. Knight

2001-01-01

75

Coherent phenomena in photonic crystals  

Microsoft Academic Search

We study the spontaneous emission, absorption, and dispersion properties of a Lambda-type atom where one transition interacts near resonantly with a double-band photonic crystal. Assuming an isotropic dispersion relation near the band edges, we show that two distinct coherent phenomena can occur. First the spontaneous emission spectrum of the adjacent free-space transition obtains ``dark lines'' (zeros in the spectrum). Second,

D. G. Angelakis; E. Paspalakis; P. L. Knight

2001-01-01

76

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

77

Functional imaging of mucociliary phenomena  

Microsoft Academic Search

We present a technique for the investigation of mucociliary phenomena on trachea explants under conditions resembling those\\u000a in the respiratory tract. Using an enhanced reflection contrast, we detect simultaneously the wave-like modulation of the\\u000a mucus surface by the underlying ciliary activity and the transport of particles embedded in the mucus layer. Digital recordings\\u000a taken at a speed of 500 frames

M. Ryser; A. Burn; Th. Wessel; M. Frenz; J. Ri?ka

2007-01-01

78

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

79

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

80

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

81

Coherent Phenomena in Photonic Crystals  

E-print Network

We study the spontaneous emission, the absorption and dispersion properties of a ${\\bf \\Lambda}$-type atom where one transition interacts near resonantly with a double-band photonic crystal. Assuming an isotropic dispersion relation near the band edges, we show that two distinct coherent phenomena can occur. First, the spontaneous emission spectrum of the adjacent free space transition obtains `dark lines' (zeroes in the spectrum). Second, the atom can become transparent to a probe laser field coupling to the adjacent free space transition.

Angelakis, D G; Knight, P L

2001-01-01

82

Coherent Phenomena in Photonic Crystals  

E-print Network

We study the spontaneous emission, the absorption and dispersion properties of a ${\\bf \\Lambda}$-type atom where one transition interacts near resonantly with a double-band photonic crystal. Assuming an isotropic dispersion relation near the band edges, we show that two distinct coherent phenomena can occur. First, the spontaneous emission spectrum of the adjacent free space transition obtains `dark lines' (zeroes in the spectrum). Second, the atom can become transparent to a probe laser field coupling to the adjacent free space transition.

D. G. Angelakis; E. Paspalakis; P. L. Knight

2000-09-26

83

Vapor explosion phenomena: Scaling considerations  

SciTech Connect

Past safety analyses considered the hazard from vapor explosions in a conservative manner where engineering judgment and conservative analyses were used to estimate the likelihood of nuclear reactor containment failure from explosion-induced missile generation [alpha-mode failure]. However, recent safety analyses may require less conservative methods to determine the hazard from vapor explosions; thus one may need to consider more detailed scaling of vapor explosion phenomena. This paper proposes particular scaling considerations for vapor explosions based on recent experimental results and that vapor explosions with prototypic reactor fuel material may be less of a hazard.

Corradini, M.L. [Univ. of Wisconsin, Madison, WI (United States)

1996-08-01

84

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; Megas, Eugenio; Pena-Benitez, Francisco

2011-07-01

85

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

86

Percolation phenomena by computer simulation  

SciTech Connect

The microstructure of cement-based materials is determined by the chemical nature and amounts of the original constituents, and the succeeding chemical hydration process. An aspect of the microstructure that is important in determining properties is how these products are arranged topologically in space. In particular, how each product phase becomes connected or disconnected (percolation threshold) plays a large role in such important properties of these porous materials as ionic diffusion, electrical conductivity, and fluid permeability. We use computer models to determine the important percolation thresholds in portland cement-based materials, covering connectivity phenomena from length scales of micrometers to meters. We show how the overall behavior of this material, from processing to final use, may be described by its percolation thresholds.

Garboczi, E.J.; Bentz, D.P. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

1995-12-31

87

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

88

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.

89

Superfluid analogies of cosmological phenomena  

E-print Network

Superfluid 3He-A gives example of how chirality, Weyl fermions, gauge fields and gravity appear in low emergy corner together with corresponding symmetries, including Lorentz symmetry and local SU(N). This supports idea that quantum field theory (Standard Model or GUT) is effective theory describing low-energy phenomena. * Momentum space topology of fermionic vacuum provides topological stability of universality class of systems, where above properties appear. * BCS scheme for 3He-A incorporates both ``relativistic'' infrared regime and ultraviolet ``transplanckian'' range: subtle issues of cut-off in quantum field theory and anomalies can be resolved on physical grounds. This allows to separate ``renormalizable'' terms in action, treated by effective theory, from those obtained only in ``transPlanckian'' physics. * Energy density of superfluid vacuum within effective theory is ~ E_{Planck}^4. Stability analysis of ground state beyond effective theory leads to exact nullification of vacuum energy: equilibrium...

Volovik, G E

2001-01-01

90

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

91

Electromechanical phenomena in semiconductor nanostructures  

NASA Astrophysics Data System (ADS)

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

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

2011-02-01

92

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

93

Optical phenomena in the open air  

NASA Astrophysics Data System (ADS)

Objects readily observed by everyone in the open air constitute fascinating phenomena. However, details on the origin of such phenomena like rainbows, halos, glories, lightning and northern lights often stay in the background whereas the combination of both observation and background knowledge will open an even more fascinating view. This article summarises the underlying physical principles of these phenomena and addresses the characteristics they have in common as well as their main differences.

Fantz, U.

2004-02-01

94

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 users 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

95

Bleed Hole Flow Phenomena Studied  

NASA Technical Reports Server (NTRS)

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

1997-01-01

96

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

97

Heavy ion beam induced phenomena in polytetrafluoroethylene  

NASA Astrophysics Data System (ADS)

This paper describes the results on thermal and chemical analysis of polytetrafluoroethylene (PTFE) film stack after high-energy heavy ion beam irradiation under atmospheric fields at room temperature. After high-energy C 6+ ion beam irradiation, the PTFE film stack was separated one by one, and then the various measurements such as differential scanning calorimetric (DSC) analysis and solid-state 19F magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy were performed to get information of the chemical reaction and structural change at the localized positions. By ion beam irradiation for PTFE at room temperature, it is suggested that the abnormal phenomena due to the change of morphology could be observed by DSC analysis. In the solid-state 19F-MAS-NMR spectroscopy of ion irradiated PTFE film including Bragg peak region, several new signals were observed besides the intense peak of -CF 2- at -124 ppm. The detected new signals in ion irradiated PTFE should be due to the changed chemical structures. The signals, which are assigned, to the tertiary carbon group with branching site (Y-type crosslinking site), perfluoro-propylene site and chain end methyl site were directly detected, though it was under the oxidation condition. Thus, although it was under the oxidation condition, the branching or crosslinking reaction was taken place with the chain scission in the matrix. Moreover, the branched chain length would become short, compared with EB-crosslinked PTFE. Hence, it could be suggested that the irradiation of heavy ion beam induced large amounts of intermediate species, compared with EB or ?-ray irradiation, and then, those would be reacted with each other in the localized area. Especially, in region of the Bragg peak, the ion beam induced more large amounts of intermediate species than in the other region.

Oshima, Akihiro; Murata, Katsuyoshi; Oka, Toshitaka; Miyoshi, Nozomi; Matsuura, Akio; Kudo, Hisaaki; Murakami, Takeshi; Katoh, Etsuko; Washio, Masakazu; Hama, Yoshimasa

2007-12-01

98

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

99

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

100

Modeling direct containment heating phenomena with CONTAIN 1. 12  

SciTech Connect

CONTAIN is a detailed mechanistic computer code developed at Sandia National Laboratories for the integrated analysis of light water reactor severe accident containment phenomena. The most recent version of the code, CONTAIN 1.12, incorporates models for the phenomena of high pressure melt ejection (HPME) and the subsequent processes collectively known as Direct Containment Heating (DCH). CONTAIN 1.12 was used to model the Limited Flight Path 8A (LFP8A) experiment conducted at the Surtsey test facility at Sandia National Laboratories. In the experiment, 50 kg of molten thermite was injected into a scale model of the Surry cavity and then blown into the Surtsey vessel by high pressure steam. A seven-cell best-estimate CONTAIN model, using only a minimum of measured data, was used to simulate the LFP8A experiment. A comparison of the experimental and calculated results indicated that CONTAIN 1.12 was accurately modeling the physical processes involved in DCH phenomena, but the method of injecting the molten debris into the cavity in the CONTAIN model was causing the code to overpredict the chemical reaction and heat transfer rates between the molten debris and the system atmosphere. CONTAIN 1.12 predicted the peak vessel pressure to within less than 2% of the experimental value, but missed the timing on the pressure peak by approximately 1.75 s over the course of a 10 s calculation. 6 refs., 6 figs.

Griffith, R.O.; Russell, N.A.; Washington, K.E.

1991-01-01

101

EMERGENT PHENOMENA IN GENETIC PROGRAMMING LEE ALTENBERG  

E-print Network

1 EMERGENT PHENOMENA IN GENETIC PROGRAMMING LEE ALTENBERG Institute of Statistics and Decision and algorith- mic properties of the tree-structured representation, both the genetics and representation can various emergent phenomena, pri- mary of which is adaptation. In genetic programming, because of the inde

Fernandez, Thomas

102

Thermoelectric phenomena via an interacting particle system  

E-print Network

Thermoelectric phenomena via an interacting particle system Christian Maes and Maarten H. van for thermoelectric phenomena in terms of an interacting particle system, a lattice electron gas dynamics, a standard reference is [1]. We present an interacting particle system for the standard thermoelectric

Maes, Christian

103

Jump phenomena of current in PZT-vibrators due to nonlinear damping of surrounding media  

Microsoft Academic Search

In some applications, surrounding media influence oscillating behavior of PZT vibrators by non-linear damping. This usually results in current jump phenomena of the supply. Such effects have been studied in detail under both atmospheric air pressure and vacuum. For a rate estimation about the influence of nonlinear crystal properties and of nonlinear damping the media influence has been minimized by

P Drgmller; G Gerlach

2001-01-01

104

Applications of speckle phenomena; Proceedings of the Seminar, San Diego, CA, July 29, 30, 1980  

Microsoft Academic Search

Topics discussed include the basic properties of speckle phenomena in imaging, in information processing, and in wavelength diversity, stellar speckle interferometry, and speckle metrology. Papers are presented on speckle propagation through the turbulent atmosphere, digital processing of images in speckle noise, observational speckle interferometry, and astronomical imaging by processing stellar speckle interferometry data. Attention is also given to speckle in

W. H. Carter

1980-01-01

105

Understanding the Physics of changing mass phenomena  

NASA Astrophysics Data System (ADS)

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

Ellermeijer, A. L.

2008-05-01

106

Disciplines Atmosphere  

E-print Network

#12;#12;Disciplines · Ecology · Atmosphere · Landscape · Geology · Hydrology · Oceanography · Study Agriculture Humidity NOAA Atmospheric Circulation Environment Urban planning Erosion Pedogenesis Morphogenesis

Laurini, Robert

107

The Atmosphere  

NSDL National Science Digital Library

This exercise is intended to reinforce the importance of Earth's atmosphere to living organisms. Topics include our bodies' interactions with the atmosphere; its composition and structure; and natural changes in the atmosphere (weather). Students will perform an actvity in which they are asked to observe and record weather conditions for four days, answer questions about their observations, and respond to a series of questions on general atmospheric characteristics. They will also learn how to convert temperature values from degrees Celsius to Fahrenheit.

Fox, Chris

108

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

109

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

110

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

111

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

112

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

NASA Astrophysics Data System (ADS)

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 observations 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 Alfvn waves and particle precipitation related to solar and magnetospheric processes. We review ionospheric processes as well as surface and space weather phenomena that drive the coupling between the troposphere and the ionosphere. Effects of aerosols, water vapor distribution, thermodynamic parameters, and cloud charge separation and electrification processes on atmospheric electricity and electromagnetic waves are reviewed. 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 perturbations 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 to solve inverse problems and outline in a final section a few challenging subjects that are important to advance our understanding of tropospheric-ionospheric coupling.

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

2012-06-01

113

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.

2007-10-12

114

Synchronization Phenomena and Epoch Filter of Electroencephalogram  

NASA Astrophysics Data System (ADS)

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

Matani, Ayumu

115

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

116

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

117

Coupled Ocean-Atmosphere Simulations  

Microsoft Academic Search

\\u000a Climate modelling for the prediction of anthropogenic global change requires to take into account the coupling phenomena between\\u000a the ocean and the atmosphere. Several approaches, ranging from simple dynamical systems studies to full size coupled General\\u000a Circulation Models (GCM) are necessary to apprehend the basic physical processes underlying the climate mean state and its\\u000a seasonal and interannual variability. In this

L. Terray; O. Thual

118

Measurement of Ions Penetration Pattern in Point to Grid Atmospheric Corona Discharge  

Microsoft Academic Search

Atmospheric plasma which has many scientific and engineering applications is a complicated phenomena because of interaction between ions, fields and neutrals. For more accurate modeling and better use of corona phenomena which is a kind of atmospheric plasma, some experimental measurements have been done in the case of point to grid corona problem and relative ion penetration pattern behind the

Ali Haghdel; Habibollah Abiri; Mohammad Reza Eskandari; Hasan Zibaeinejad

2011-01-01

119

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

120

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

121

Classifying prion and prion-like phenomena.  

PubMed

The universe of prion and prion-like phenomena has expanded significantly in the past several years. Here, we overview the challenges in classifying this data informatically, given that terms such as "prion-like", "prion-related" or "prion-forming" do not have a stable meaning in the scientific literature. We examine the spectrum of proteins that have been described in the literature as forming prions, and discuss how "prion" can have a range of meaning, with a strict definition being for demonstration of infection with in vitro-derived recombinant prions. We suggest that although prion/prion-like phenomena can largely be apportioned into a small number of broad groups dependent on the type of transmissibility evidence for them, as new phenomena are discovered in the coming years, a detailed ontological approach might be necessary that allows for subtle definition of different "flavors" of prion / prion-like phenomena. PMID:24549098

Harbi, Djamel; Harrison, Paul M

2014-01-01

122

Ambroise August Libeault and psychic phenomena.  

PubMed

Some nineteenth-century hypnosis researchers did not limit their interest to the study of the conventional psychological and behavioral aspects of hypnosis, but also studied and wrote about psychic phenomena such as mental suggestion and clairvoyance. One example, and the topic of this paper, was French physician Ambroise August Libeault (1823-1904), who influenced the Nancy school of hypnosis. Libeault wrote about mental suggestion, clairvoyance, mediumship, and even so-called poltergeists. Some of his writings provide conventional explanations of the phenomena. Still of interest today, Libeault's writings about psychic phenomena illustrate the overlap that existed during the nineteenth-century between hypnosis and psychic phenomena--an overlap related to the potentials of the mind and its subconscious activity. PMID:19862897

Alvarado, Carlos S

2009-10-01

123

Fractal Geometry and Spatial Phenomena A Bibliography  

E-print Network

Fractal Geometry and Spatial Phenomena A Bibliography January 1991 Mark MacLennan, A. Stewart. MEASUREMENT ISSUES........................................................... 8 II.1 ESTIMATION OF FRACTAL DIMENSION - GENERAL ISSUES .......... 8 II.2 ESTIMATION OF FRACTAL DIMENSION FOR CURVES/PROFILES ... 9 II.3

California at Santa Barbara, University of

124

A Multiagent Approach to Modelling Complex Phenomena  

Microsoft Academic Search

Designing models of complex phenomena is a difficult task in engineering that can be tackled by composing a number of partial\\u000a models to produce a global model of the phenomena. We propose to embed the partial models in software agents and to implement\\u000a their composition as a cooperative negotiation between the agents. The resulting multiagent system provides a global model

Francesco Amigoni; Viola Schiaffonati

2008-01-01

125

Reproductive phenomena of a sexual buffelgrass plant  

E-print Network

lines apomictic lines. 21 22 REPRODUCTIVE PHENOMENA OF A SEXUAL BUFFELGRASS PLANT INTRODUCTION Buffelgrass, Pennisetum ciliare (L. ) Link, is a polymorphic, perennial, warm-season, bunch grass with a native range extending from Africa to India... lines apomictic lines. 21 22 REPRODUCTIVE PHENOMENA OF A SEXUAL BUFFELGRASS PLANT INTRODUCTION Buffelgrass, Pennisetum ciliare (L. ) Link, is a polymorphic, perennial, warm-season, bunch grass with a native range extending from Africa to India...

Taliaferro, Charles Millard

2012-06-07

126

Clustering and other exotic phenomena in nuclei  

Microsoft Academic Search

. Nuclei feature a rich variety of many-body phenomena. Especially the clustering of nucleons, which leads to molecule like\\u000a structures, and halos formed by weakly bound nucleons are regarded as exotic phenomena that standard many-body methods like\\u000a the shell\\u000a model have difficulties to describe. On the other hand cluster models that build in such structures explicitly use very simplistic\\u000a effective

T. Neff; H. Feldmeier

2008-01-01

127

An Econophysics Model for the Migration Phenomena  

E-print Network

Knowing and modelling the migration phenomena and especially the social and economic consequences have a theoretical and practical importance, being related to their consequences for development, economic progress (or as appropriate, regression), environmental influences etc. One of the causes of migration, especially of the interregional and why not intercontinental, is that resources are unevenly distributed, and from the human perspective there are differences in culture, education, mentality, collective aspirations etc. This study proposes a new econophysics model for the migration phenomena.

Gheorghiu, Anca

2012-01-01

128

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.

129

The Atmosphere  

Microsoft Academic Search

\\u000a The atmosphere is closely related to hydrology in a fundamental manner. It will, therefore, be appropriate to make a brief\\u000a introduction to the subject of atmosphere. As pointed out in chapter 1, atmosphere is a thin shell of gases, which is held\\u000a close to the earth by the gravitational attraction and is commonly called the air. These gases seem to

Pukh Raj Rakhecha; Vijay P. Singh

130

ActivePassive radiolocation of dangerous natural phenomena  

NASA Astrophysics Data System (ADS)

In nature one observes strong deviations from thermodynamic equilibrium. The most dangerous natural phenomena proceeding in a thermodynamically irreversible way, are accompanied by the initiation of nonthermal impulse radio and optical radiation, the intensity and amplitude-frequency characteristics of which may serve as a measure of irreversibility while making the passive radiolocation and simultaneously as an information characteristic of the degree of the phenomenon's approach to the stage of maximum development. The active radiolocation of natural phenomena at the stage of thermodynamic irreversibility has a number of distinct features caused by the high speed of their progress and anomalies of the dielectric properties and accordingly, effective scattering area of natural radio targets. The above is the physical basis of the method proposed by the author, that of the active-passive radiolocation of dangerous natural phenomena such as thunderstorms-both naturally developing and provoked by flying vehicles or other modifying means, avalanches, landslides, catastrophic atmospheric eddies and showers, sudden destruction of sea, river and lake ice and so on. Active-passive radar sounding of cloudiness presumes radical changes in the air traffic control in thunderous situations in the take-off and landing areas of flying vehicles as well as along the airways. Thermodynamic irreversibility turns out to be an important factor in the process of the interaction of ice with heavy-duty icebreakers (nuclear-powered vessels) causing their anomalous corrosion. The non-thermal radio radiation arising at the deformation of ice cover under the pressure of an icebreaker or under the action of wind load, may be used while choosing the route and tactics of the ice-breaker's progress, for the hydrometeorological service of other sea and coastal operations. The completed investigations of the thermodynamically irreversible natural phenomena have found practical application, but their wide utilization is still ahead. The experiments of active-passive radiolocation have been carried out at the experimental proving grounds, in laboratories, in weather planes, on board an atomic-powered icebreaker. Simultaneously there have been developing the theory of thermodynamically irreversible phase transitions, in particular deformation-crystallization processes. So far, there is no generally accepted term denoting the proposed method of the active-passive radiolocation of dangerous natural phenomena (using thermodynamic irreversibility).

Kachurin, L. G.

1990-05-01

131

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

132

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.

133

Processing and display of atmospheric phenomenaa data  

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

134

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

135

Critical phenomena in gravitational collapse - Living Reviews  

E-print Network

As first discovered by Choptuik, the black hole threshold in the space of initial data for general relativity shows both surprising structure and surprising simplicity. Universality, power-law scaling of the black hole mass, and scale echoing have given rise to the term ``critical phenomena''. They are explained by the existence of exact solutions which are attractors within the black hole threshold, that is, attractors of codimension one in phase space, and which are typically self-similar. This review gives an introduction to the phenomena, tries to summarize the essential features of what is happening, and then presents extensions and applications of this basic scenario. Critical phenomena are of interest particularly for creating surprising structure from simple equations, and for the light they throw on cosmic censorship and the generic dynamics of general relativity.

C. Gundlach

2000-01-17

136

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

137

Atmospheric Optics  

NSDL National Science Digital Library

Les Cowley, a physicist and expert in atmospheric optics, developed this website to share his knowledge about the visual spectacles produced by light connecting with water drops, dust, and ice crystals. Students can discover how and where the amazing displays are formed. The site is divided into five main categories: Rays and Shadows, Water Droplets, Rainbows, Ice Halos, and High Atmosphere. Within each topic, users can find an abundance of information and amazing images of the particular spectacle. By downloading the HaloSim3 Software in the Ice Halo link, users can view simulations of common and rare halos. Visitors will learn a lot about the atmosphere through this remarkable website.

Cowley, Les

138

Planetary Atmospheres  

NASA Astrophysics Data System (ADS)

Observation, characterization, and understanding the atmospheres of our neighboring planets and moons in the solar system provide essential inputs for addressing broad science goals. These goals include identifying the conditions that are favorable for producing and supporting biological activity, managing the effects of human activity on the Earth's atmosphere, and planning and evaluating observations of extra-solar planets. Here we review the current state of knowledge, pose key science questions, recommend enhancements in the research infrastructure for investigation of planetary atmospheres, and propose new space missions with specific science objectives.

Huestis, D. L.; Adams, N. G.; Atreya, S. K.; Baines, K. H.; Beebe, R. F.; Bolton, S. J.; Bougher, S. W.; Coustenis, A.; Edgington, S. G.; Friedson, A. J.; Galand, M.; Griffith, C. A.; Guberman, S. L.; Hammel, H. B.; Hofstadter, M. D.; Ingersoll, A. P.; Lunine, J. I.; Mendillo, M.; Moses, J.; Mueller-Wodarg, I.; Orton, G. S.; Rages, K. A.; Slanger, T. G.; Titov, D. V.; Vasavada, A. R.; Wong, A.-S.; Yelle, R.

2002-08-01

139

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

140

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.

141

Possible new wave phenomena in the brain  

E-print Network

We propose to search for new wave phenomena in the brain by using interference effects in analogy to the well-known double slit (Young) experiment. This method is able to extend the range of oscillation frequencies to much higher values than currently accessible. It is argued that such experiments may test the hypothesis of the wave nature of information coding.

Jerzy Szwed

2009-06-15

142

Prediction of dynamic phenomena in massed explosions  

Microsoft Academic Search

bumps. Based on the nature of shock bumps and the nature of their occurrence, the method devised for predicting dynamic phenomena includes the following: an analysis of the geological, mine-engineering, and geomechanical situation at the deposit; the identification of dynamically active geological structures; determination of the volume of the excavated space and goal; evaluation of the seismic energy of the

M. V. Kurlenya; A. Ao Eremenko; S. P. Usol'tsev; N. I. Sklyar; V. A. Eremenko

1996-01-01

143

Wave Phenomena in an Acoustic Resonant Chamber  

ERIC Educational Resources Information Center

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

Smith, Mary E.; And Others

1974-01-01

144

Conference on Transport Phenomena with Moving Boundaries  

E-print Network

Conference on Transport Phenomena with Moving Boundaries 9th -10th October, Berlin, Germany VOF-of-Fluid (VOF) method. For the examination of mass transfer, single bubbles are held in counter require numerical methods that resolve the free phase boundary. Based on the VOF-method, mass transfer

Bothe, Dieter

145

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

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

2014-07-01

146

Observations of Nonlinear Phenomena in Rotordynamics  

Microsoft Academic Search

Observations, analysis and understanding of nonlinear rotordynamic phenomena observed in aircraft gas turbine engines and other high-speed rotating machinery over the course of the author's career are described. Included are observations of sum-and-difference frequency response; effects of roller bearing clearance; relaxation oscillations; subharmonic response; chaotic response; and other generic nonlinear responses such as superharmonic and ultra-subharmonic response.

Fredric F. Ehrich

2008-01-01

147

Cooperative phenomena in strongly correlated electron systems  

Microsoft Academic Search

In this review we present results of our theoretical study of cooperative phenomena in strongly correlated electron systems obtained within various generalizations of the Falicov-Kimball model. The primary goal of this study was to identify crucial interactions that lead to the stabilization of the specific cooperative phenomenon, and then try to elaborate its comprehensive microscopic description. The main attention is

Pavol Farkasovsk

2010-01-01

148

Analysis Of Plunging Phenomena In Water Reservoirs  

Microsoft Academic Search

Two analyses of plunging phenomena in reservoirs are presented, one based upon a simple energy conserving flow and the other upon a gradually varied two-layer system. The various types of interfacial profiles are described and the depth at the plunge point is determined. The predicted plunge depth agrees reasonably well with the laboratory measurements of SINGH and SHAH (1971).

S. B. Savage; J. Brimberg

1975-01-01

149

Critical phenomena in globally coupled excitable elements  

NASA Astrophysics Data System (ADS)

Critical phenomena in globally coupled excitable elements are studied by focusing on a saddle-node bifurcation at the collective level. Critical exponents that characterize divergent fluctuations of interspike intervals near the bifurcation are calculated theoretically. The calculated values appear to be in good agreement with those determined by numerical experiments. The relevance of our results to jamming transitions is also mentioned.

Ohta, Hiroki; Sasa, Shin-Ichi

2008-12-01

150

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...

151

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.

152

Corruption, fraud and cybercrime as dehumanizing phenomena  

Microsoft Academic Search

Purpose The purpose of this paper is to describe corruption, fraud and cybercrime as dehumanizing phenomena. Design\\/methodology\\/approach Berdiaeff's notion of slavery and Sartre's concepts of lie and bad faith are used in order to put light on the dehumanizing effects of corruption, fraud and cybercrime over social life itself. Findings Corruption, fraud and cybercrime constitute dehumanizing processes

Michel Dion

2011-01-01

153

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

154

Reduplication phenomena: body, mind and archetype.  

PubMed

The many biological and few psychodynamic explanations of reduplicative syndromes tend to have paralleled the dualism of the phenomenon with organic theories concentrating on form and dynamic theories emphasising content. This paper extends the contribution of psychoanalytic thinking to an elucidation of the form of the delusion. Literature on clinical and aetiological aspects of reduplicative phenomena is reviewed alongside a brief examination of psychoanalytic models not overtly related to these phenomena. The human experience of doubles as universal archetype is considered. There is an obvious aetiological role for brain lesions in delusional misidentifications, but psychological symptoms in an individual can rarely be reduced to an organic disorder. The splitting and doubling which occurs in the phenomena have resonances in cultural mythology and in theories from different schools of psychodynamic thought. For the individual patient and doctor, it is a diverting but potentially empty debate to endeavour to draw strict divisions between what is physical and what is psychological although both need to be investigated. Nevertheless, in patients in whom there is clear evidence of an organic contribution to aetiology a psychodynamic understanding may serve to illuminate the patient's experience. Organic brain disease or serious functional illness predispose to regression to earlier modes of archetypical and primitive thinking with concretization of the metaphorical and mythological world. Psychoanalytic models have a contribution in describing the form as well as the content of reduplicative phenomena. PMID:11003374

Garner, J

2000-09-01

155

Quark confinement and surface critical phenomena  

SciTech Connect

Surface critical phenomena and the related onset of Goldstone modes probe the fundamental properties of the confining flux in Quantum Chromodynamics. New ideas on surface roughening and their implications for lattice studies of quark confinement are presented. Problems with the oversimplified string description of the Wilson flux sheet are discussed.

K.J. Juge, J. Kuti and C.J. Morningstar

1999-10-20

156

Dream phenomena induced by chronic levodopa therapy  

Microsoft Academic Search

Summary Twenty-seven of eighty-eight (30.7%) Parkinsonian patients on chronic levodopa or levodopa\\/carbidopa therapy developed drug related dream phenomena. The patients reported three separate types of new dreams which we have classified as vivid dreams, night terrors and nightmares. These dreams are correlated to the duration of levodopa therapy although the mechanism of their production is unclear.

B. Sharf; Ch. Moskovitz; M. D. Lupton; H. L. Klawans

1978-01-01

157

Certain relativistic phenomena in crystal optics  

Microsoft Academic Search

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

Lim Chee-Seng

1980-01-01

158

Jet flow phenomena during nucleate boiling  

Microsoft Academic Search

Boiling phenomena are with highly complex nonlinear and nonequilibrium characteristics, which cause diversity and complexity of boiling nucleation. In the present paper, an experimental investigation was conducted to investigate the nucleate boiling behavior on a very fine heating wire. Using zoom routine and CCD camera system, the dynamical process of nucleate boiling was visually observed and several modes of jet

H. Wang; X. F. Peng; B. X. Wang; D. J. Lee

2002-01-01

159

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 Alarcn

160

Solid-State Physical Phenomena and Effects Part III  

Microsoft Academic Search

This is the third in a series of four articles describing solid-state phenomena. Twelve solid-state phenomena and physical effects are provided. All of the twelve phenomena belong to a group which includes effects related to the dielectric properties of materials and transport phenomena for particles other than electrons or holes.

E. Scheibner

1962-01-01

161

Crystal Melting and Wall Crossing Phenomena  

E-print Network

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.

Masahito Yamazaki

2010-02-09

162

Search of Traces of Geophysical Phenomena in Series of Latitude Determinations on Prismatic Astrolabe in Poltava  

NASA Astrophysics Data System (ADS)

The influences of some geophysical phenomena on the long-term observation results which are obtained in Poltava with prismatic astolabe, are have been studied. It is established: 1) the non-polar variations of latitude reveals global cycles, typical for uniform system the Ears - the ocean - the atmosphere; 2) the correlation degree between non-polar zenith shifts and Solar activity index in media-term region (6-12 years) of spectrum is very high.

Zalivadnyi, N. M.; Khalyavina, L. Ya.; Borisyuk, T. Ye.

163

Precise Measurement of Atmospheric Gamma Rays at High Altitude  

Microsoft Academic Search

We have been observing the atmospheric gammaray spectrum from 30 GeV to 10 TeV for many years with the emulsion chamber at balloon altitude. Atmospheric gamma rays at high altitude of several g\\/cm2 are almost produced by a single interaction of primary cosmic rays, and useful to interpret the various cosmic-ray phenomena inside the atmosphere. Especially, more conclusive understanding for

T. Kobayashi; Y. Komori; K. Yoshida; J. Nishimura

2001-01-01

164

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...

165

Coherence Phenomena in Coupled Optical Resonators  

NASA Technical Reports Server (NTRS)

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

Smith, D. D.; Chang, H.

2004-01-01

166

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

167

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

168

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

169

Emission phenomena in a SHS combustion wave  

Microsoft Academic Search

There are numerous experimental data indicating that the action of electromagnetic and magnetic fields on the combustion wave\\u000a of self-propagating high-temperature synthesis (SHS) changes the process kinetics and the structure and properties of the\\u000a reaction products. Emission phenomena in the combustion wave have received less attention. High rates of chemical energy dissipation\\u000a in SHS (1012 W\\/m3) are accompanied by physical

Yu. M. Maksimov; A. I. Kirdyashkin; R. M. Gabbasov; V. G. Salamatov

2009-01-01

170

SUPERCONVERGENCE PHENOMENA ON THREE-DIMENSIONAL MESHES  

Microsoft Academic Search

We give an overview of superconvergence phenomena in the flnite element method for solving three-dimensional problems, in particular, for el- liptic boundary value problems of second order over uniform meshes. Some di-culties with superconvergence on tetrahedral meshes are presented as well. For a given positive integer m we prove that there is no tetrahedralization of R3 whose all edges are

MICHAL K

171

Detonation wave phenomena in bubbled liquid  

Microsoft Academic Search

Shock wave propagation was investigated in two phase media consisting of diluted glycerin (85%) and reactive gas bubbles. To understand these complex phenomena, we first performed a numerical analysis and experimental studies of single bubbles containing a reactive gas-mixture. For the two-phase mixtures, a needle matrix bubble-generator enabled us to produce a homogeneous bubble distribution with a size dispersion less

A. E. Beylich

1990-01-01

172

Detonation wave phenomena in bubbled liquid  

Microsoft Academic Search

Shock wave propagation was investigated in two phase media consisting of diluted glycerin (85%) and reactive gas bubbles. To understand these complex phenomena, we first performed a numerical analysis and experimental studies of single bubbles containing a reactive gas-mixture. For the two-phase mixtures, a needle matrix bubble-generator enabled us to produce a homogeneous bubble distribution with a size dispersion less

A. Glhan; A. E. Beylich

1990-01-01

173

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

174

Stratospheric pollution related ultraviolet radiation phenomena  

Microsoft Academic Search

RBsumB. - Une revue concise des phCnom6nes ultraviolets qui jouent un r6le dans la pollution stratospherique est prCsentCe. Son but est de mettre en Cvidence les aspects principaux par des exemples rkcents. L'accent est place sur les nouvelles donnCes obtenues depuis sept ans au sujet du rayonnement ultraviolet solaire. Abstract. - A short review of ultraviolet phenomena related to stratospheric

M. Ackerman

1978-01-01

175

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

176

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

177

Evaporation phenomena in f(T) gravity  

E-print Network

We formulate evaporation phenomena in a generic model of generalized teleparallel gravity in Weitzenbock spacetime with diagonal and non-diagonal tetrads basis. We also perform the perturbation analysis around the constant torsion scalar solution named Nariai spacetime which is an exact solution of field equations as the limiting case of the Schwarzschild-de Sitter and in the limit where two back hole and their cosmological horizons coincide. By a carefully analysis of the horizon perturbation equation, we show that (anti)evaporation can not happen if we use a diagonal tetrad basis. This result implies that a typical black hole in any generic form of generalized teleparallel gravity is frozen in its initial state if we use the diagonal tetrads. But in the case of non-diagonal tetrads the analysis is completely different. By a suitable non trivial non-diagonal tetrad basis we investigate the linear stability of the model under perturbations of the metric and torsion simultaneously. We observe that in spite of the diagonal case, both evaporation and anti evaporation can happen. The phenomena depend on the initial phase of the horizon perturbation. In the first mode when we restrict ourselves to the first lower modes the (anti)evaporation happens. So, in non-diagonal case the physical phenomena is reasonable. This is an important advantage of using non-diagonal tetrads instead of the diagonal ones. We also see that this is an universal feature, completely independent from the form of the model.

M. J. S. Houndjo; D. Momeni; R. Myrzakulov; M. E. Rodrigues

2013-04-02

178

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.

179

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

180

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

181

Microgravity Transport Phenomena Experiment (MTPE) Overview  

NASA Technical Reports Server (NTRS)

The Microgravity Transport Phenomena Experiment (MTPE) is a fluids experiment supported by the Fundamentals in Biotechnology program in association with the Human Exploration and Development of Space (BEDS) initiative. The MTP Experiment will investigate fluid transport phenomena both in ground based experiments and in the microgravity environment. Many fluid transport processes are affected by gravity. Osmotic flux kinetics in planar membrane systems have been shown to be influenced by gravimetric orientation, either through convective mixing caused by unstably stratified fluid layers, or through a stable fluid boundary layer structure that forms in association with the membrane. Coupled transport phenomena also show gravity related effects. Coefficients associated with coupled transport processes are defined in terms of a steady state condition. Buoyancy (gravity) driven convection interferes with the attainment of steady state, and the measurement of coupled processes. The MTP Experiment measures the kinetics of molecular migration that occurs in fluids, in response to the application of various driving potentials. Three separate driving potentials may be applied to the MTP Experiment fluids, either singly or in combination. The driving potentials include chemical potential, thermal potential, and electrical potential. Two separate fluid arrangements are used to study membrane mediated and bulk fluid transport phenomena. Transport processes of interest in membrane mediated systems include diffusion, osmosis, and streaming potential. Bulk fluid processes of interest include coupled phenomena such as the Soret Effect, Dufour Effect, Donnan Effect, and thermal diffusion potential. MTP Experiments are performed in the Microgravity Transport Apparatus (MTA), an instrument that has been developed specifically for precision measurement of transport processes. Experiment fluids are contained within the MTA fluid cells, designed to create a one dimensional flow geometry of constant cross sectional area, and to facilitate fluid filling and draining operations in microgravity. The fluid cells may be used singly for bulk solutions, or in a Stokes diaphragm configuration to investigate membrane mediated phenomena. Thermal and electrical driving potentials are applied to the experiment fluids through boundary plates located at the ends of the fluid cells. In the ground based instrument, two constant temperature baths circulate through reservoirs adjacent to the boundary plates, and establish the thermal environment within the fluid cells. The boundary plates also serve as electrodes for measurement and application of electrical potentials. The Fluid Manipulation System associated with the MTA is a computer controlled system that enables storage and transfer of experiment fluids during on orbit operations. The system is used to automatically initiate experiments and manipulate fluids by orchestrating pump and valve operations through scripted sequences. Unique technologies are incorporated in the MTA for measurement of fluid properties. Volumetric Flow Sensors have been developed for precision measurement of total fluid volume contained within the fluid cells over time. This data is most useful for measuring the kinetics of osmosis, where fluid is transported from one fluid cell to another through a semipermeable membrane. The MicroSensor Array has been designed to perform in situ measurement of several important fluid parameters, providing simultaneous measurement of solution composition at multiple locations within the experiment fluids. Micromachined sensors and interface electronics have been developed to measure temperature, electrical conductivity, pH, cation activity, and anion activity. The Profile Refractometer uses a laser optical system to directly image the fluid Index of Refraction profile that exists along the MTA fluid cell axis. A video system acquires images of the RI profile over time, and records the transport kinetics that occur upon application of chemical, thermal, or electrical driving potentials. Image proces

Mason, Larry W.

1999-01-01

182

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.

Comet

2012-03-06

183

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

184

Atmosphere Webquest  

NSDL National Science Digital Library

Use the websites and games provided to answer questions, complete diagrams, and learn more about our Earth's atmosphere TOPIC 1 - Weather vs. Climate - Let's start with a game. Open up Online Stopwatch and click on the stopwatch setting. - Use the stopwatch to time yourself as you play through all three levels of The Weather Game. - On your own piece of paper write down how long it took you to pass all ...

Talley, Mr.

2011-09-27

185

Submarine Atmospheres  

Microsoft Academic Search

Atmosphere control in submarines has developed to meet the operational requirements. Until\\u000a the end of WWII submarines were primarily semi-submersibles spending most of their time on the surface\\u000a and submerged for periods of 12h or less. However, rudimentary control of oxygen and carbon\\u000a dioxide was available in some WWI boats. In the latter years of WWII, the requirement for longer

Waldemar Mazurek

186

Oscillating heat pipe simulation considering dryout phenomena  

NASA Astrophysics Data System (ADS)

In heat transport devices such as oscillating heat pipe (OHP), dryout phenomena is very important and avoided in order to give the optimum performance. However, from the previous studies (including our studies), the dryout phenomena in OHP and its mechanism are still unclear. In our studies of OHP (Senjaya and Inoue in Appl Thermal Eng 60:251-255, 2013; Int J Heat Mass Transfer 60:816-824, 2013; Int J Heat Mass Transfer 60:825-835, 2013), we introduced the importance and roles of liquid film in the operating principle of OHP. In our previous simulation, the thickness of liquid film was assumed to be uniform along a vapor plug. Then, dryout never occurred because there was the liquid transfer from the liquid film in the cooling section to that in the heating section. In this research, the liquid film is not treated uniformly but it is meshed similarly with the vapor plugs and liquid slugs. All governing equations are also solved in each control volume of liquid film. The simulation results show that dryout occurs in the simulation without bubble generation and growth. Dryout is started in the middle of vapor plug, because the liquid supply from the left and right liquid slugs cannot reach until the liquid film in the middle of vapor plug, and propagates to the left and right sides of a vapor plug. By inserting the bubble generation and growth phenomena, dryout does not occur because the wall of heating section is always wetted during the bubble growth and the thickness of liquid film is almost constant. The effects of meshing size of liquid film and wall temperature of heating section are also investigated. The results show that the smaller meshing size, the smaller liquid transfer rate and the faster of dryout propagation. In the OHP with higher wall temperature of heating section, dryout and its propagation also occur faster.

Senjaya, Raffles; Inoue, Takayoshi

2014-10-01

187

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

188

Atmospheric Aerosols  

NASA Technical Reports Server (NTRS)

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

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

1994-01-01

189

Observations of cometary plasma wave phenomena  

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

190

Observations of cometary plasma wave phenomena  

NASA Astrophysics Data System (ADS)

The ICE plasma wave investigation utilized very long electric antennas (100 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 Halley, and (2) information on the processes that developed in the coma and tail of Giacobini-Zinner. The authors summarize ICE plasma wave measurements associated with both comet encounters and relate the very high sensitivity ICE observations to corresponding measurements from the other Halley spacecraft.

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

1986-12-01

191

On periodicity of solar wind phenomena  

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

192

BEAM COUPLING PHENOMENA IN FAST KICKER SYSTEMS.  

SciTech Connect

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

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

2001-06-18

193

Collective Phenomena In Volume And Surface Barrier Discharges  

NASA Astrophysics Data System (ADS)

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

Kogelschatz, U.

2010-07-01

194

Solid-State Physical Phenomena and Effects Part IV  

Microsoft Academic Search

This is the fourth in a series of articles dealing with phenomena of the solid state. Nineteen solid-state phenomena and physical effects are described. This group of phenomena includes primarily the resonance effects, that is, those effects which can be described in terms of discrete energy levels rather than energy bands.

E. Scheibner

1962-01-01

195

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

196

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

197

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

NASA Astrophysics Data System (ADS)

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

Gershenzon, Naum; Bambakidis, Gust

2014-05-01

198

Dynamic phenomena in coronal flux tubes  

Microsoft Academic Search

The study of stellar atmospheres and the determination of specific physical mechanisms, geometries, and magnetic structures by which coronae are maintained is examined. Ultraviolet and soft X-ray components observed in the radiative output of cool stars and the Sun require counterentropic temperature gradients for their explanation. The existence of a hot corona is recognized as a result of mechanical or

J. T. Mariska; J. P. Boris

1982-01-01

199

Physically-based simulation of twilight phenomena  

Microsoft Academic Search

We present a physically-based approach to compute the colors of the sky during the twilight period before sunrise and after sunset. The simulation is based on the theory of light scattering by small particles. A realistic atmosphere model is assumed, consisting of air molecules, aerosols, and water. Air density, aerosols, and relative humidity vary with altitude. In addition, the aerosol

Jrg Haber; Marcus A. Magnor; Hans-Peter Seidel

2005-01-01

200

Sulfation phenomena in fluidized bed combustion systems  

Microsoft Academic Search

Fluidized bed combustors (FBCs) are noted for their ability to capture SO2 in situ via direct reaction with Ca-based sorbents. However, despite more than 30 years of intensive study of sulfation processes in atmospheric FBC boilers and numerous laboratory studies, there are still many uncertainties and disagreements on the subject. In particular, the mechanisms of the sulfation reaction are still

E. J. Anthony; D. L. Granatstein

2001-01-01

201

Novel Sound Phenomena in Impure Superfluids  

NASA Astrophysics Data System (ADS)

In the last decade, new techniques for producing impure superfluids with unique properties have been developed. This new class of systems includes superfluid helium confined to aerogel, HeII with different impurities, superfluids in Vycor glasses, and watergel. These systems exhibit very unusual properties including unexpected acoustic features. We discuss the sound properties of these systems and show that sound phenomena in impure superfluids are modified from those in pure superfluids. We calculate the coupling between temperature and pressure oscillations for impure superfluids and show that this coupling increases significantly. This leads to the existence in impure superfluids of such unusual sound phenomena as slow "pressure" waves and fast "temperature" waves. This also decreases the threshold values for nonlinear processes as compared to pure superfluids. Sound conversion, which has been observed in pure superfluids only by high intensity waves should be observed at moderate sound amplitude in impure superfluids. Cerenkov emission of second sound by first sound (which has never been observed in superfluids) could be observed in impure superfluids. Even the nature of the sound modes in impure superfluids turns out to be changed. We have also derived for the first time the nonlinear hydrodynamic equations for superfluid helium in aerogel.

Brusov, Peter; Brusov, Pavel

202

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.

203

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

204

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

205

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

206

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 Rnyi 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

207

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

208

Relationship between Yield Point Phenomena and the Nanoindentation Pop-in Behavior of Steel  

SciTech Connect

Pop-ins on nanoindentation load-displacement curves of a ferritic steel were correlated with yield drops on its tensile stress-strain curves. To investigate the relationship between these two phenomena, nanoindentation and tensile tests were performed on annealed specimens, prestrained specimens, and specimens aged for various times after prestraining. Clear nanoindentation pop-ins were observed on annealed specimens, which disappeared when specimens were indented right after the prestrain, but reappeared to varying degrees after strain aging. Yield drops in tensile tests showed similar disappearance and appearance, indicating that the two phenomena, at the nano- and macro-scale, respectively, are closely related and influenced by dislocation locking by solutes (Cottrell atmospheres).

Ahn, T.-H. [Seoul National University; Oh, C.-S. [Korean Institute of Materials Science; Lee, K. [Technical Research Laboratories, Republic of Korea; George, Easo P [ORNL; Han, H. N. [Seoul National University

2012-01-01

209

International workshop on Time-Variable Phenomena in the Jovian System  

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

210

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

211

Coherence Phenomena in Coupled Optical Resonators  

NASA Technical Reports Server (NTRS)

Quantum coherence effects in atomic media such as electromagnetically-induced transparency and absorption, lasing without inversion, super-radiance and gain-assisted superluminality have become well-known in atomic physics. But these effects are not unique to atoms, nor are they uniquely quantum in nature, but rather are fundamental to systems of coherently coupled oscillators. In this talk I will review a variety of analogous photonic coherence phenomena that can occur in passive and active coupled optical resonators. Specifically, I will examine the evolution of the response that can occur upon the addition of a second resonator, to a single resonator that is side-coupled to a waveguide, as the coupling is increased, and discuss the conditions for slow and fast light propagation, coupled-resonator-induced transparency and absorption, lasing without gain, and gain-assisted superluminal pulse propagation. Finally, I will discuss the application of these systems to laser stabilization and gyroscopy.

Smith, David D.

2007-01-01

212

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

213

Observations of Cometary Plasma Wave Phenomena  

NASA Astrophysics Data System (ADS)

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 traversed cometary regions that complemented those sampled by Vega and Sakigake, it is important to compare observations from the three missions that carried dedicated wave instruments. Here we summarize ICE plasma wave measurements associated with both comet encounters and relate the very high sensitivity ICE observations to corresponding measurements from the other Halley spacecraft.

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

1987-11-01

214

Study of Travelling Interplanetary Phenomena Report  

NASA Astrophysics Data System (ADS)

Scientific progress on the topic of energy, mass, and momentum transport from the Sun into the heliosphere is contingent upon interdisciplinary and international cooperative efforts on the part of many workers. Summarized here is a report of some highlights of research carried out during the SMY/SMA by the STIP (Study of Travelling Interplanetary Phenomena) Project that included solar and interplanetary scientists around the world. These highlights are concerned with coronal mass ejections from solar flares or erupting prominences (sometimes together); their large-scale consequences in interplanetary space (such as shocks and magnetic 'bubbles'); and energetic particles and their relationship to these large-scale structures. It is concluded that future progress is contingent upon similar international programs assisted by real-time (or near-real-time) warnings of solar activity by cooperating agencies along the lines experienced during the SMY/SMA.

Dryer, Murray

1987-09-01

215

Modeling diffusive phenomena using non integer derivatives  

NASA Astrophysics Data System (ADS)

In order to evaluate losses during energetical transfers, accurate battery models are needed in embedded power systems. The accuracy of those is all the more important as in hybrid vehicles, batteries are continuously charged and discharged. This paper deals with a dynamical model of NiMH battery, the originality of which lays on the use of non integer derivatives to model diffusion phenomena. With this method, we represent the battery by an equivalent electric scheme, whose components are identified by an experimental technique called Electrochemical Impedance Spectroscopy (E.I.S.)". This identification process has been applied to a commercially available NiMH cell and its relevance checked by comparing digital simulations and laboratory experiments.

Kuhn, E.; Forgez, C.; Friedrich, G.

2004-03-01

216

Attachment and suggestion-related phenomena.  

PubMed

This study uses a new classification of suggestion-related phenomena and investigates the relationship between attachment styles and reaction to suggestion. The authors used 3 traditional experimental tasks: a stimulus-misinformation task, an inkblot perception task, and a subjective estimation of a nonexistent difference task. A measure of adult attachment was also taken. Participants with a high attachment insecurity as opposed to those with a low one were less influenced by suggestions in the recall phase of the memory task. Results are discussed within the framework of suggestion models, the dual models of social behavior, and the adult attachment model. Implications of findings are limited to simple suggestion rather than the more complex set of responses related to hypnotizability. PMID:24568326

Rotaru, Tudor-?tefan; Dafinoiu, Ion

2014-01-01

217

Density-Functional Theory of Thermoelectric Phenomena  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

218

Reversion phenomena of Cu-Cr alloys  

NASA Technical Reports Server (NTRS)

Cu-Cr alloys which were given various aging and reversion treatments were investigated in terms of electrical resistivity and hardness. Transmission electron microscopy was one technique employed. Some results obtained are as follows: the increment of electrical resistivity after the reversion at a constant temperature decreases as the aging temperature rises. In a constant aging condition, the increment of electrical resistivity after the reversion increases, and the time required for a maximum reversion becomes shorter as the reversion temperature rises. The reversion phenomena can be repeated, but its amount decreases rapidly by repetition. At first, the amount of reversion increases with aging time and reaches its maximum, and then tends to decrease again. Hardness changes by the reversion are very small, but the hardness tends to soften slightly. Any changes in transmission electron micrographs by the reversion treatment cannot be detected.

Nishikawa, S.; Nagata, K.; Kobayashi, S.

1985-01-01

219

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

220

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

221

Large Interface Simulation in Multiphase Flow Phenomena  

SciTech Connect

An attempt to represent multiphase multi-scale flow, filling the gap between Direct Numerical Simulation (DNS) and averaged approaches, is the purpose of this paper. We present a kind of Large Interface (LI) simulation formalism obtained after a filtering process on local instantaneous conservation equations of the two-fluid model which distinguishes between small scales and large scales contributions. LI surface tension force is also taken into account. Small scale dynamics call for modelization and large scale for simulation. Joined to this formalism, a criterion to recognize LI's is developed. It is used in an interface recognition algorithm which is qualified on a sloshing case and a bubble oscillation under zero-gravity. This method is applied to a rising bubble in a pool that collapses at a free surface and to a square-base basin experiment where splashing and sloshing at the free surface are the main break-up phenomena. (authors)

Henriques, Aparicio; Coste, Pierre; Pigny, Sylvain [CEA-Grenoble, 17, rue des Martyrs 38054 Grenoble Cedex 9 (France); Magnaudet, Jacques [Institut Mecanique des Fluides de Toulouse, 1 Allee du Professeur Camille Soula, 31400 Toulouse (France)

2006-07-01

222

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

223

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

224

Combining observations to study heliospheric phenomena  

NASA Astrophysics Data System (ADS)

There is currently a more diverse range of observatories scattered around the solar system than at any time in the past. As a consequence, heliophysics - the study of the effect of the Sun on the Solar System - has entered a boom period. The Heliophysics Integrated Observatory, HELIO, has established a collaborative environment where scientists can discover, understand and model the connection between solar phenomena, interplanetary disturbances and their effects on the planets. The project is designed around a serviceoriented architecture with needed capabilities that support metadata curation and search, data location and retrieval, and data processing and storage being established as independent services. HELIO provides integrated access to the data and metadata from the domains that constitute heliophysics - solar, heliospheric, geophysics and planetary. More than 50 event catalogues can be used in the search, together with10 feature catalogues; data from more than 150 instruments from nearly 50 observatories can be accessed. A comprehensive user interface is available and the services can also be accessed through IDL; a workflow tool provides the ability to combine services together and it is possible to execute programmes on demand including propagation models. We will show how HELIO can be used to explore how phenomena evolve as they propagate through the Solar System. Effects related to structures in the solar wind, coronal mass ejections and particle events are reported using observations from multiple platforms, including occasions where the same phenomenon interacts with multiple planetary environments. The HELIO Consortium includes thirteen groups from the UK, France, Ireland, Italy, Switzerland, Spain and the US; the project started in June 2009 and has a duration of 42 months.

Bentley, R. D.

2012-09-01

225

Applications of speckle phenomena; Proceedings of the Seminar, San Diego, CA, July 29, 30, 1980  

NASA Astrophysics Data System (ADS)

Topics discussed include the basic properties of speckle phenomena in imaging, in information processing, and in wavelength diversity, stellar speckle interferometry, and speckle metrology. Papers are presented on speckle propagation through the turbulent atmosphere, digital processing of images in speckle noise, observational speckle interferometry, and astronomical imaging by processing stellar speckle interferometry data. Attention is also given to speckle in optical fibers, speckle imaging under nonisoplanatic conditions, new trends in stellar speckle interferometry, and speckle metrology for the study of small particles and droplets.

Carter, W. H.

1980-01-01

226

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

227

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

228

Natural phenomena hazards, Hanford Site, south central Washington  

SciTech Connect

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

Tallman, A.M.

1996-04-16

229

Different states of the transient luminous phenomena in Hessdalen valley, Norway.  

NASA Astrophysics Data System (ADS)

The transient luminous phenomena's in Hessdalen valley has at least been observed for 200 years, since 1811, when the priest Jacob T. Krogh did the first written documentation. The valley is located in the middle of Norway, isolated and with sub arctic climate. The former mining district has no more than 140 inhabitants, and the deep mines are closed and filled with water. The valley has been under scientific surveillance since 1998 when the first automated and remote controlled observatory was put into action. Today a Norwegian, Italian and French collaboration runs 3 different research stations inside the valley. Each year a scientific field campaign establishes 4 temporary bases in the mountains, and up to 100 students and researchers man these bases for up to 14 days in september when the moon is down. The Hessdalen phenomena is not easy to detect, and approximately only 20 observations is done each year. The work done the last 14 years suggests that the phenomenon has different states, at least 6 detected so far. The states are so different that to se a coupling between them is difficult. New work done into dusty plasma physics suggest that the different phenomena's may be of the same origin, since the ionized grains of dusty plasma can change states from weakly coupled (gaseous) to crystalline, altering shape/formation and leading to different phenomena. Optical spectrometry from 2007 suggested that the luminous phenomena consisted of burning air and dust from the valley. Work done by G.S Paiva and C.A Taft suggests that radon decay from closed mines may be the mechanism that ionizes dust and triggers this phenomena. The 6 different main states of the Hessdalen phenomena, Doublet, Fireball, Plasma ray, Dust cloud, Flash and Invisible state is described and discussed. Investigation of the atmosphere inside the Hessdalen valley with low frequency directional RADAR, reveals large areas of ionized matter, giving a reflecting area big enough to saturate the input of the radar receiver. Together with long living time, ground analysis and radio active measurements, do not support the radon decay theory, and other forms of ionizing mechanisms must be investigated. The phenomenon's energy source is still not revealed, and the question of internal or external power source is also unexplained.

Hauge, B. G.; Montebugnoli, S.

2012-04-01

230

Anomalous Nuclear Phenomena Assocoated with Ultrafast Processes  

NASA Astrophysics Data System (ADS)

Quantum physics predicts the existence of an underlying sea of zero-point energy at every point in the universe. A minority of physicists accept it as real energy which we cannot directly sense since it is the same everywhere, even inside our bodies and measuring devices. If the zero-point energy is real, there is the possibility that it can be tapped as a source of power or be harnassed to generate a propulsive force for space travel. However if some asymmetric variation of the Casimir force could be identified one could in effect sail through space as if propelled by a kind of quantum fluctuation wind. In our previous papers, anomalous excess heat and localized nuclear reactions on the surface of electrodes in electrolysis cells have been observed. A physical model of transient vortex dynamics with torsion coherence with the zero point energy has been proposed by Xingliu Jiang based on the ultrafast processes of triple phases area of tip effect on the electrode surface. Considering the large equiverlent capacitance of electrochemical double layer, it is presumed that the double layer can exhibit nonlinear electrical response with spatial and temporal variations confined to microscopic areas by tip effect. Experimental results of transient processes with ultrafast phenomena with nanosecond duration in electrical discharge systems including electrolysis cells and corona discharge have been presented.

Jiang, Xingliu; Zhou, Xiaoping; Liu, Chun; Wang, Liying; Zhang, Zhongliang

2007-04-01

231

Detonation wave phenomena in bubbled liquid  

NASA Astrophysics Data System (ADS)

Shock wave propagation was investigated in two phase media consisting of diluted glycerin (85%) and reactive gas bubbles. To understand these complex phenomena, we first performed a numerical analysis and experimental studies of single bubbles containing a reactive gas-mixture. For the two-phase mixtures, a needle matrix bubble-generator enabled us to produce a homogeneous bubble distribution with a size dispersion less than 5%. The void fraction ?0 was varied over one order of magnitude, ?0=0.2-2%. It was found that there exists a critical value of shock strength above which bubble explosion starts. Once a bubble explodes, it stimulates the adjacent bubbles to explode due to emission of a blast wave; this process is followed by a series of similar events. A steady detonationlike wave propagates as a precurser with a constant velocity which is much higher than that of the first wave. To study the structure of the detonation wave the measured pressured profiles were averaged by superimposing 50 shots.

Glhan, A.; Beylich, A. E.

1990-07-01

232

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

233

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

234

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

235

Viscous theory of surface noise interaction phenomena  

NASA Technical Reports Server (NTRS)

A viscous linear surface noise interaction problem is formulated that includes noise production by an oscillating surface, turbulent or vortical interaction with a surface, and scattering of sound by a surface. The importance of viscosity in establishing uniqueness of solution and partitioning of energy into acoustic and vortical modes is discussed. The results of inviscid two dimensional airfoil theory are used to examine the interactive noise problem in the limit of high reduced frequency and small Helmholtz number. It is shown that in the case of vortex interaction with a surface, the noise produced with the full Kutta condition is 3 dB less than the no Kutta condition result. The results of a study of an airfoil oscillating in a medium at rest are discussed. It is concluded that viscosity can be a controlling factor in analyses and experiments of surface noise interaction phenomena and that the effect of edge bluntness as well as viscosity must be included in the problem formulation to correctly calculate the interactive noise.

Yates, J. E.

1980-01-01

236

Local wind phenomena at the Waldstein/Weidenbrunnen FLUXNET site  

NASA Astrophysics Data System (ADS)

Two Intensive Observation Periods (IOP) of the EGER project (ExchanGE processes in mountainous Regions) were performed at the Waldstein/Weidenbrunnen FLUXNET site (DE-Bay) in the Fichtelgebirge/Germany. IOP1 was conducted in September and October 2007, IOP2 in June and July 2008. The project is focused on the detailed quantification of relevant processes within the soil-vegetation-atmosphere system by observing diurnal and annual cycles of energy, water and trace gases. The atmospheric boundary layer was profiled with an acoustic and radar remote sensing system (SODAR-RASS). The SODAR provided 10 minute mean profiles up to 500 m a.g.l. In contrast to IOP1 a second SODAR (referred to as miniSODAR) without a RASS-extension was used during IOP2 and provided 5 minute mean profiles up to 200 m a.g.l. The aims of this study included the observation of local wind phenomena at the site, the determination of their frequency and their relation to surrounding meteorological circumstances. During both IOPs some nocturnal low-level jets (LLJ) with a duration time of several hours were observed. Maximum horizontal wind speed (vhmax) was in the range from 11.5 to 12.3 m s-1 for IOP1 and in the range from 8.0 to 11.6 m s-1 for IOP2. The height of vhmax varied between 100 and 230 m a.g.l. Most of the LLJ events were characterised by an approaching flow from south-easterly directions. Another phenomenon was observed in the profile of the wind vector. It showed a strong turn of the wind direction with increasing height. At night times and during the morning hours flows above the canopy came from the east while the geostrophic wind approached from the south-westerly directions. The topography and resulting canalising effects seem to be the reason for the generation of LLJ as well as for the turn of the wind direction.

Schier, S.; Meixner, F. X.; Foken, T.

2009-04-01

237

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

238

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

239

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

240

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

241

Impact vaporization: Late time phenomena from experiments  

NASA Technical Reports Server (NTRS)

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

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

1987-01-01

242

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

243

Sunlight photochemistry of retort-water organonitrogen compounds in an inert atmosphere  

Microsoft Academic Search

The elevated temperature of an oil-shale codisposal process will enhance the atmospheric emission of volatile components. Important among the organic compounds are the nitrogen heterocycles and aromatic primary amines, which are chacterized by malodor and low order thresholds and by resistance to biotreatment. Atmospheric lifetimes are determined by various transport (e.g., dispersion, washout) and transformation phenomena. Photochemical alteration will be

E. R. Blatchley; C. G. Daughton; J. F. Thomas

1986-01-01

244

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

245

Logical and illogical exegeses of hydrometeorological phenomena in ancient Greece  

Microsoft Academic Search

Technological applications aiming at the exploitation of the natural sources appear in all ancient civilizations. The unique phenomenon in the ancient Greek civilization is that technological needs triggered physical explanations of natural phenomena, thus enabling the foundation of philosophy and science. Among these, the study of hydrometeorological phenomena had a major role. This study begins with the Ionian philosophers in

D. Koutsoyiannis; N. Mamassis; A. Tegos

2007-01-01

246

PREFACE: XI Latin American Workshop on Nonlinear Phenomena  

Microsoft Academic Search

The XI Latin American Workshop on Nonlinear Phenomena (LAWNP) has been held in Bzios-RJ, Brazil, from 5-9 October 2009. This international conference is one in a series that have gathered biennially, over the past 21 years, physicists and other scientists who direct their work towards several aspects of nonlinear phenomena and complex systems. The main purpose of LAWNP meetings is

Celia Anteneodo; Marcos G. E. da Luz

2010-01-01

247

Collective phenomena in photonic, plasmonic and hybrid structures.  

PubMed

Preface to a focus issue of invited articles that review recent progress in studying the fundamental physics of collective phenomena associated with coupling of confined photonic, plasmonic, electronic and phononic states and in exploiting these phenomena to engineer novel devices for light generation, optical sensing, and information processing. PMID:22109052

Boriskina, Svetlana V; Povinelli, Michelle; Astratov, Vasily N; Zayats, Anatoly V; Podolskiy, Viktor A

2011-10-24

248

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.

249

Phenomena of liquid drop impact on solid and liquid surfaces  

Microsoft Academic Search

The fluid dynamic phenomena of liquid drop impact are described and reviewed. These phenomena include bouncing, spreading and splashing on solid surfaces, and bouncing, coalescence and splashing on liquid surfaces. Further, cavitation and the entrainment of gas into an impacted liquid may be observed. In order to distinguish properly between the results of different experiments different impact scenarios are discussed.

Martin Rein

1993-01-01

250

From Psychic Claims to Science: Testing Psychic Phenomena with  

E-print Network

From Psychic Claims to Science: Testing Psychic Phenomena with Statistics Jessica Utts Department Knowing ­ Some Responses Experience "I know I love my kids." "Gut Feeling" "I know psychic phenomena [statistical] evidence, and an explanation. #12;Psi/Psychic/ESP/Anomalous Cognition Having information

Utts, Jessica

251

Modeling and simulation of heat transfer phenomena during investment casting  

Microsoft Academic Search

Determining the heat transfer phenomena during casting processes is an important parameter for measuring the overall performance of process. It gives information about the properties of the metal being casted and its possible behavior in the mold during casting process. Improper determination of heat transfer phenomena and use of improper molding materials and casting conditions leads to defects such as

M.M.A. Rafique; J. Iqbal

2009-01-01

252

EMERGENT PHENOMENA IN GENETIC PROGRAMMING1 LEE ALTENBERG  

E-print Network

EMERGENT PHENOMENA IN GENETIC PROGRAMMING1 LEE ALTENBERG Institute of Statistics and Decision of the tree-structured representation, both the genetics and rep- resentation can evolve as an emergent various emergent phenomena, primary of which is adaptation. In genetic programming, because

Altenberg, Lee

253

Nonlinear electrokinetic phenomena in microfluidic devices  

NASA Astrophysics Data System (ADS)

This thesis addresses nonlinear electrokinetic mechanisms for transporting fluid and particles in microfluidic devices for potential applications in biomedical chips, microelectronic cooling and micro-fuel cells. Nonlinear electrokinetics have many advantages, such as low voltage, low power, high velocity, and no significant gas formation in the electrolyte. However, they involve new and complex charging and flow mechanisms that are still not fully understood or explored. Linear electrokinetic fingering that occurs when a fluid with a lower electrolyte concentration advances into one with a higher concentration is first analyzed. Unlike earlier miscible fingering theories, the linear stability analysis is carried out in the self-similar coordinates of the diffusing front. This new spectral theory is developed for small-amplitude gravity and viscous miscible fingering phenomena in general and applied to electrokinetic miscible fingering specifically. Transient electrokinetic fingering is shown to be insignificant in sub-millimeter micro-devices. Nonlinear electroosmotic flow around an ion-exchange spherical granule is studied next. When an electric field is applied across a conducting and ion-selective porous granule in an electrolyte solution, a polarized surface layer with excess counter-ions is created. The flux-induced polarization produces a nonlinear slip velocity to produce micro-vortices around this sphere. This polarization layer is reduced by convection at high velocity. Two velocity scalings at low and high electric fields are derived and favorably compared with experimental results. A mixing device based on this mechanism is shown to produce mixing efficiency 10-100 times higher than molecular diffusion. Finally, AC nonlinear electrokinetic flow on planar electrodes is studied. Two double layer charging mechanisms are responsible for the flow---one due to capacitive charging of ions from the bulk electrolyte and one due to Faradaic reactions at the electrode that consume or produce ions in the double layer. Faradaic charging is analyzed for specific reactions. From the theory, particular electrokinetic flows above the electrodes are selected for micropumps and bioparticle trapping by specifying the electrode geometry and the applied voltage and frequency.

Ben, Yuxing

254

Magnetoresistive phenomena in nanoscale magnetic systems  

NASA Astrophysics Data System (ADS)

Nanomagnetic materials are playing an increasingly important role in modern technologies. A particular area of interest involves the interplay between magnetism and electric transport, i.e. magnetoresistive properties. Future generations of field sensors and memory elements will have to be on a length scale of a few nanometers or smaller. Magnetoresistive properties of such nanoscale objects exhibit novel features due to reduced dimensionality, complex surfaces and interfaces, and quantum effects. In this dissertation theoretical aspects of three such nanoscale magnetoresistive phenomena are discussed. Very narrow magnetic domain walls can strongly scatter electrons leading to an increased resistance. Specifically, this dissertation will cover the newly predicted effect of magnetic moment softening in magnetic nanocontacts or nanowires. Atomically thin domain walls in Ni exhibit a reduction, or softening, of the local magnetic moments due to the noncollinearity of the magnetization. This effect leads to a strong enhancement of the resistance of a domain wall. Magnetic tunnel junctions (MTJs) consist of two ferromagnetic electrodes separated by a thin layer of insulating material through which current can be carried by electron tunneling. The resistance of an MTJ depends on the relative orientation of the magnetization of the two ferromagnetic layers, an effect known as tunneling magnetoresistance (TMR). A first-principles analysis of CoFeB|MgO|CoFeB MTJs will be presented. Calculations reveal that it is energetically favorable for interstitial boron atoms to reside at the interface between the electrode and MgO tunneling barrier, which can be detrimental to the TMR effect. Anisotropic magnetoresistance (AMR) is the change in resistance of a ferromagnetic system as the orientation of the magnetization is altered. In this dissertation, the focus will be on AMR in the tunneling regime. Specifically we will present new theoretical results on tunneling AMR (TAMR) in two systems: (i) planar MTJs with CoFe electrodes and (ii) fully broken magnetic break junctions. In both cases electronic resonances in the electrodes lead to complex angular and bias dependence of the TAMR. The theoretical studies demonstrate the basic physical phenomenon behind recent experimental data.

Burton, John D.

255

Seepage phenomena on Mars at subzero temperature  

NASA Astrophysics Data System (ADS)

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

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

256

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

257

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

258

Progress of research in cell-in-cell phenomena.  

PubMed

The discovery of a nonphagocytotic process of cell-in-cell phenomena can be traced to over a century ago. However, its biological significance remains poorly understood. Three types of cell-in-cell phenomena have been described so far, termed "cannibalism," "emperipolesis," and "entosis." These three kinds of cell-in-cell phenomena, apart from a common feature of one cell internal to another, are distinct both cytologically and biologically. In this review, we discussed them in their morphology, cell recognition, penetration mechanisms, and physiological roles, respectively. PMID:22271432

Yang, Yue-Qin; Li, Ji-Cheng

2012-03-01

259

Probing the atmosphere and atmospheric events using dense seismic networks (Invited)  

NASA Astrophysics Data System (ADS)

Data from global seismic networks have revealed in detail branches of seismic energy through the solid Earth. We know analogous branches of acoustic energy in the Earths atmosphere exist; however, they have been elusive due to a lack of densely-spaced infrasound stations. Infrasound array recordings are very useful as they provide constraints on the signal wave properties (such as phase velocity and direction) that cannot be extracted from single stations, however they just provide spot measurements of the infrasound wavefield as it strikes the Earths surface and do not tell us in detail how acoustic branches vary with range and azimuth from the source. Such information from direct observations could deepen our understanding of long-range sound propagation and be useful for tests of atmospheric models of effective sound speed and propagation codes. It is well known that acoustic signals from atmospheric phenomena couple to seismic and can be recorded above noise. Although coupling can complicate the waveforms, coupled signals that are abrupt and recorded well above noise on a dense grid can be used to reveal the structure of the acoustic branches. We have used dense broadband seismic networks in the continental US, including the transportable USArray, to study acoustic-to-seismic coupled signals from atmospheric phenomena. We report our observations of branches of acoustic signals from a large bolide that burst above several hundred broadband seismic stations in the Pacific NW and the results of our comparisons of recorded data with synthetics.

Hedlin, M. A.; Drob, D. P.; Degroot-Hedlin, C. D.; Walker, K. T.

2009-12-01

260

Low energy electron collision parameters for modeling auroral/dayglow phenomena  

NASA Astrophysics Data System (ADS)

From the tenuous atmospheres of Pluto and Triton to the higher pressure atmospheres of Earth and Titan, electron-collisions with molecular nitrogen continue to warrant attention. The airglow emissions of N2 from the atmospheres of Earth and planetary satellites have been extensively observed. Accurate, consistent cross section data is a necessity for accurate models of how upper atmospheres behave. This enables determinations of solar energy inputs and atmospheric expansion and contraction, which influences satellite orbits for instance. Recent work by Lean et al. [1], Stevens et al. [2], and Kato et al. [3] appear to substantiate our e^-+N2 excitation and emission work (e.g., Johnson et al. [4], Malone et al. [5], Young et al. [6] and references therein). Recently, we have focused on the near-threshold-to-peak region of N2 with the goal of providing low energy collision parameters of the X^1?g^+(0)--A^3?u^+, B^3?g, W^3?u, B^'3?u^-, a^'1?u^-, a^1?g, w^1?u, C^3?u, and E^3?g^+ transitions for modeling auroral and dayglow phenomena in these N2-rich atmospheres. The Lyman-Birge-Hopfield (LBH) emissions, from a^1?g(v^')--X^1?g^+(v^'') transitions, are `bellwether' measurements for diurnal Terrestrial Space Weather variations [7]. However, near-threshold cross section data is still lacking for the a^1?g state, as well as the `slow-cascade' a^'1?u^- and w^1?u contributors to LBH emissions. In addition, Vegard-Kaplan (VK) emissions, from the A^3?u^+(v^')--X^1?g^+(v^'') transitions, recently observed in Titan's thermosphere [2], require further improved monoenergetic laboratory measurements. New electron energy-loss measurements, along with direct excitation (integral) cross sections, are presented for excitation of the lower states of N2, with finely-spaced impact energy increments in the threshold-to-peak region. Our recent work, including vibrationally resolved excitation, addresses these atmospheric data needs.[4pt] [1] Lean et al., 2011, JGR, 116, A01102. ,[4] Johnson et al., 2005, JGR, 110, A11311. [2] Stevens et al., 2011, JGR, 116, A05304. [5] Malone et al., 2009, J. Phys. B, 42, 135201. [3] Kato et al., 2010, PRA, 81, 042717. ;;, [6] Young et al., 2010, J. Phys. B, 43, 135201. [7] Ajello et al., 2011, UV Molecular Spectroscopy from Electron Impact for Applications to Planetary Atmospheres and Astrophysics, Book Chapter 28, published in ``Charged Particle and Photon Interactions with Matter'' Recent Advances, Applications, and Interfaces-Eds., Hatano et al., Taylor & Francis, Boca Raton, FL.

Malone, Charles P.

2011-11-01

261

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...

262

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...

263

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

264

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

265

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

266

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

267

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 ...

Sa-Seoane, Joel

2011-01-01

268

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

269

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

270

INTERFACIAL PHENOMENA IN ION IMPLANTED SILICON-ON-INSULATOR MATERIALS  

E-print Network

INTERFACIAL PHENOMENA IN ION IMPLANTED SILICON-ON-INSULATOR MATERIALS By ANTONIO FERNANDO SAAVEDRA patience on more than one occasion as we prepared for choir tour. The fondest memories of my life were

Florida, University of

271

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

272

Critical appraisal of piping phenomena in earth dams  

Microsoft Academic Search

This paper presents a comprehensive review of published literature on soil piping phenomena. The first tools to design earth\\u000a dams to resist piping were developed during 19101935. Filter criteria for dispersive soils was refined in the 1970s. Piping\\u000a phenomena are generally defined as: (1) heave, (2) internal erosion, (3) backwards erosion, although other modes are possible.\\u000a Recent work on piping

Kevin S. Richards; Krishna R. Reddy

2007-01-01

273

A review of power laws in real life phenomena  

NASA Astrophysics Data System (ADS)

Power law distributions, also known as heavy tail distributions, model distinct real life phenomena in the areas of biology, demography, computer science, economics, information theory, language, and astronomy, amongst others. In this paper, it is presented a review of the literature having in mind applications and possible explanations for the use of power laws in real phenomena. We also unravel some controversies around power laws.

Pinto, Carla M. A.; Mendes Lopes, A.; Machado, J. A. Tenreiro

2012-09-01

274

Search for New Phenomena in the CDF Top Quark Sample  

E-print Network

We present recent results from CDF in the search for new phenomena appearing in the top quark samples. These results use data from proton-antiproton collisions at sqrt{s} = 1.96 TeV corresponding to an integrated luminosity ranging from 195 pb^-1 to 760 pb^-1. No deviations are observed from the Standard Model expectations, so upper limits on the size of possible new phenomena are set.

Kevin Lannon; for the CDF collaboration

2006-12-05

275

Classification of Transient Phenomena in Distribution System using wavelet Transform  

NASA Astrophysics Data System (ADS)

An efficient procedure for classification of transient phenomena in distribution systems is proposed in this paper. The proposed method has been applied to classify some transient phenomena such as inrush current, load switching, capacitor switching and single phase to ground fault. The new scheme is based on wavelet transform algorithm. All of the events for feature extraction and test are simulated using Electro Magnetic Transient Program (EMTP). Results show high accuracy of proposed method.

Sedighi, Alireza

2014-05-01

276

On the multiple structure of atmospheric vortices  

NASA Astrophysics Data System (ADS)

Various scales of the multiple-vortex phenomena observed in atmospheric vortices are reviewed and summarized. The nonaxisymmetric feature clearly seen in small-scale vortices such as tornadoes is also recognized in the vortices of tropical cyclones. On the basis of both the physical resemblances and the swirl ratio similarity, this asymmetry in tropical cyclones is concluded to be a manifestation of multiple vortices. It is suggested that the evolution of a vortex from one-cell to two-cell to multiple vortices is a common feature in nature found not only in tornadoes, but also in other kinds of vortices, ranging from dust devils to tropical cyclones.

Mitsuta, Yasushi; Monji, Nobutaka; Ishikawa, Hirohiko

1987-12-01

277

Modeling Behavioral and Brain Imaging Phenomena in Transcription Typing with Queuing Networks and Reinforcement Learning Algorithms  

E-print Network

, and then describes how the model simulated the two brain imaging phenomena and three behavioral phenomena in learning). In this paper we focus on modeling the learning aspect of the behavioral phenomena and brain imaging phenomenaModeling Behavioral and Brain Imaging Phenomena in Transcription Typing with Queuing Networks

Wu, Changxu (Sean)

278

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

279

Sub-photosphere to Solar Atmosphere Connection  

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

280

Atmosphere Explorer orbit adjust propulsion system  

NASA Technical Reports Server (NTRS)

The Atmosphere Explorer-C (AE-C) spacecraft was launched into a highly elliptical orbit by a two-stage Delta 1900 vehicle on December 15, 1973. Its mission is to observe and study phenomena in the earth's atmosphere at altitudes between 150 and 4000 kilometers with several excursions down to 130 kilometers. An Orbit Adjust Propulsion System (OAPS) is included on the spacecraft in order (1) to perform low perigee maneuvers at 130 to 150 kilometers; (2) to periodically restore apogee in order to offset the effect of aerodynamic drag at perigee; and (3) to provide the capability for occasional large attitude maneuvers. This paper describes the configuration of the OAPS and the design characteristics of its individual components. Special emphasis is placed on the valving arrangement, which provides a means of adjusting the center-of-mass of the spacecraft through control of the distribution and usage of the propellant within the system.

Woodruff, W. L.; Cooley, J. L.; Stewart, B.; Morningstar, R. E.

1974-01-01

281

The Atmosphere of Venus  

NASA Technical Reports Server (NTRS)

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

Hansen, J. E. (editor)

1975-01-01

282

Atmospheric Pressure Indicator.  

ERIC Educational Resources Information Center

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

Salzsieder, John C.

1995-01-01

283

Climate Sciences: Atmospheric Thermodynamics  

E-print Network

1 Climate Sciences: Atmospheric Thermodynamics Instructor: Lynn Russell, NH343 http://aerosol.ucsd.edu/courses.html Text: Curry & Webster Atmospheric Thermodynamics Ch1 Composition Ch2 Laws Ch3 Transfers Ch12 Energy Climate Sciences: Atmospheric Thermodynamics Instructor: Lynn Russell, NH343 http

Russell, Lynn

284

Atmospheric refraction: a history  

Microsoft Academic Search

We trace the history of atmospheric refraction from the ancient Greeks up to the time of Kepler. The concept that the atmosphere could refract light entered Western science in the second century B.C. Ptolemy, 300 years later, produced the first clearly defined atmospheric model, containing air of uniform density up to a sharp upper transition to the ether, at which

Waldemar H. Lehn; Siebren van der Werf

2005-01-01

285

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.

286

Development of Weather Forecasting Skill for Students in the Atmospheric Sciences Program at the University of Washington  

E-print Network

real-time surface map analysis and case studies illustrating specific phenomena such as mesoscale forecasting. Separate analyses are carried out for different categories of forecast parameters. Time series for the Study of the Atmosphere and Ocean 2 University of Washington Department of Atmospheric Sciences Abstract

Mass, Clifford F.

287

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

SciTech Connect

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

Cooper, T.D.

1996-09-30

288

Measurement of gas-switching related diffusion phenomena in horizontal MOCVD reactors using biacetyl luminescence  

NASA Astrophysics Data System (ADS)

The fading of concentration profiles due to diffusion, occuring after gas source switching in MOCVD growth, was simulated by biacetyl luminescence experiments. In particular the influence of thermally induced memory cells on the concentration transients was investigated. Biacetyl molecules were used instead of macroscopic particles (for instance TiO 2) because not only can the flow patterns thus be visualized, but also a more realistic simulation of diffusion phenomena is obtained. It is shown that memory cells give rise to an increase of the residence times of gases inside the reactor. For typical MOCVD conditions, increases of several seconds were measured. The influence on interface sharpness of a GaAs/AlGaAs heterojunction is discussed. Residence times were recorded as a function of the most important hydrodynamic parameters in the MOCVD process, both at atmospheric pressure and at low pressure.

Visser, E. P.; Govers, C. A. M.; Giling, L. J.

1990-05-01

289

(abstract) Detection of Mesoscale Oceanic Phenomena in the Southern California Bight via ERS-1 SAR  

NASA Technical Reports Server (NTRS)

ERS-1 SAR images are examined with the intent of identifying mesoscale oceanic phenomena in the Southern California Bight (SCB). The SCB is a region of dynamic physical and biological processes, and as such has long been studied. The ERS-1 SAR images are augmented with other remote sensing data, including SIR-C SAR, AVHRR, ERS-1 ATSR, and Space Shuttle hand-held photography. Analysis of these images has revealed a more dynamic mesoscale field than was previously suspected. Eddies with scales on the order of 20-30 km in diameter have been the most common mesoscale features evident, but the presence of oceanic fronts and internal waves, as well as atmospheric internal waves, have been documented as well. The multisensor data record will provide insight as to the underlying ocean and meterological conditions that lead to the prevalence especially of the eddies in this region.

Holt, Ben; McWilliams, James; DiGiacomo, Paul M.

1996-01-01

290

Comprehending emergent systems phenomena through direct-manipulation animation  

NASA Astrophysics Data System (ADS)

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

Aguirre, Priscilla Abel

291

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

PubMed Central

Electric discharge phenomena in metalsolvent 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

292

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

SciTech Connect

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

Mitkin, V.N.; Galkin, P.S.; Denisova, T.N. [and others

1998-07-01

293

Atmospheric sciences assistantships  

NASA Astrophysics Data System (ADS)

Research assistantships for graduate students in the atmospheric sciences are available from the National Center for Atmospheric Research (NCAR). Research topics should cover atmospheric dynamics, climatology, cloud physics, atmospheric chemistry and radiation, upper atmosphere physics, solar and space physics, oceanography, or environmental and societal impact assessment. Appointments are half-time and offer salaries of $8085 for students who have passed comprehensive examinations and $7520 for those who have not. Maximum tenure for Ph.D. candidates is usually two years, but M.S. candidates are usually restricted to 1 year. In unusual cases, an additional year may be possible.

294

The Magnetic Field in the Solar Atmosphere  

E-print Network

This publication provides an overview of magnetic fields in the solar atmosphere with the focus lying on the corona. The solar magnetic field couples the solar interior with the visible surface of the Sun and with its atmosphere. It is also responsible for all solar activity in its numerous manifestations. Thus, dynamic phenomena such as coronal mass ejections and flares are magnetically driven. In addition, the field also plays a crucial role in heating the solar chromosphere and corona as well as in accelerating the solar wind. Our main emphasis is the magnetic field in the upper solar atmosphere so that photospheric and chromospheric magnetic structures are mainly discussed where relevant for higher solar layers. Also, the discussion of the solar atmosphere and activity is limited to those topics of direct relevance to the magnetic field. After giving a brief overview about the solar magnetic field in general and its global structure, we discuss in more detail the magnetic field in active regions, the quie...

Wiegelmann, Thomas; Solanki, Sami K

2014-01-01

295

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

296

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

297

The effects of meteoroids on the Earth atmosphere  

NASA Astrophysics Data System (ADS)

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

Popova, Olga

298

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

299

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

300

Nonlinear Alfvn wave phenomena in the planetary magnetosphere  

NASA Astrophysics Data System (ADS)

Three nonlinear Alfvn wave phenomena in the planetary magnetosphere are discussed: (1) magnetohydrodynamic parametric instabilities induced by a nonlinear standing Alfvn wave, (2) parametric excitation of Alfvn and Langmuir waves by a nonlinear electromagnetic whistler wave, and (3) parametric generation of electromagnetic waves in the vicinity of electron plasma frequency via nonlinear coupling of Langmuir and Alfvn waves. Observational evidence in support of these nonlinear Alfvn wave phenomena, such as the auroral Alfvn-acoustic turbulence and the auroral Langmuir-Alfvn-whistler (LAW) events, in the planetary magnetosphere is presented.

Chian, A. C.-L.

1995-01-01

301

Particles Spreading Phenomena in the Case of Glass Thermal Spraying  

NASA Astrophysics Data System (ADS)

The spreading phenomena of particles during thermal spraying are quite difficult to observe given the kinetics of the process. In this work, the splat formation of glass and alumina is theoretically compared, showing that glass transition and low-thermal conductivity yield a higher ratio between cooling and flattening times, which strongly modifies their spreading behavior. Wipe tests show that splashsplat transition temperature can be modified by the glass composition and its subsequent hydrodynamic properties. The detection of peculiar remaining objects, such as fibers and wavelets shows the possibility of freezing some phenomena that are totally unobservable with crystalline oxides, except with high-velocity observations.

Poirier, Thierry; Planche, Marie Pierre; Landemarre, Olivier; Coddet, Christian

2008-12-01

302

A numerical simulation of the phenomena in Be plasma  

NASA Astrophysics Data System (ADS)

In this paper, we present the numerical simulation of the Be deposition phenomena using the Thermionic Vacuum Arc (TVA) method. The Be marker layer must be adherent to the substrate and compact to resemble bulk beryllium. Thermionic Vacuum Arc (TVA) is an externally heated cathode arc which can be established in high vacuum condition, in vapors of the anode material. The arc is ignited between a heated cathode provided with a Whenelt cylinder and the anode which is a crucible containing the material to be evaporated [1]. We have used the COMSOL software to simulate the Be deposition phenomena using the TVA method.

Gavrila, Camelia; Lungu, Cristian P.; Gruia, Ion

2011-05-01

303

Circumsolar sky radiation and turbidity of the atmosphere.  

PubMed

A statistical treatment of field measurements carried out by the Astrophysical Observatory of the Smithsonian Institution is presented. The brightness of a band of sky 10 degrees wide, concentric with the sun, has been determined. Measurements were obtained at two high altitude stations (Table Mountain and Montezuma) with the aid of a pyranometer constructed by C. G. Abbot and L. B. Aldrich. The primary object was to obtain an idea of the integral scattering of the sun's radiation by the atmospheric aerosol. Results have been used to determine long-periodic changes in the scattering properties of the atmosphere and their relation to other phenomena. PMID:20126011

Angstrm, A

1974-03-01

304

ARES : an in situ sensor to characterize Mars atmospheric electricity  

NASA Astrophysics Data System (ADS)

The Atmospheric Relaxation and Electric Field sensor (ARES) is a compact (200g) instrument devoted to the investigation of atmospheric electricity at the surface of Mars. It can measure the ionization state of the atmosphere, the electric fields that result from various charging mechanisms and investigate the planet global electrical circuit. Atmospheric electrical phenomena are an important issue in many processes at the surface of Mars: dust transport, surface and atmospheric chemistry as well as habitability of the planet through their role in the production of oxydized constituents. A global atmospheric electrical circuit is likely to exist on Mars, between the surface and the ionosphere, with similarities and differences with the Earth's circuit. Atmospheric ionization should be similar to that of the Earth's stratosphere but impact charging through collisions between dust particles moved by the wind and the surface, or between dust particles themselves, is expected to be the dominant charging mechanism on Mars. Intense electric fields, possibly capable of producing electrical breakdown, are expected at the time of dust storms and in the vicinity of dust devils. Atmospheric electricity is also involved in several processes that have a noticeable impact on the surface and atmosphere. At times of dust storms, electrostatic forces on fine electrically charged dust grains may become larger than aerodynamic forces due to the wind. They are expected to play a significant role in the dynamics of suspended dust particles and their interaction with the surface, thus on the processes that contribute to the erosion and long term evolution of the surface. By energizing the free electrons, the atmospheric electric fields control their interaction with both the surface and the atmospheric gases. They have thus a definite role in the chain of physical and chemical processes that govern the chemical state of surface materials and the production of oxidized constituents in the atmosphere with far reaching consequences on the sustainability of proper conditions for life. The ELF and VLF electric fields measured by ARES can help in investigating electrical breakdown phenomena in the atmosphere and detect wave emissions from the distant ionized environment of Mars as well as ionospheric cavity resonances. In addition characterizing the radio-electric background is a necessary step to plan experiments using radio-techniques that will be used in the future to conduct deep probing for liquid water which remains as a core goal of the Mars exploration

Montmessin, F.; Godefroy, M.; Hamelin, M.; Berthelier, J. J.; Yahi, S.; Aplin, K.; Simoes, F.; Szago, K.

2009-04-01

305

The Mars atmosphere as seen from Curiosity  

NASA Astrophysics Data System (ADS)

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

Mischna, Michael

306

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

307

Mutual Information, Synergy and Some Curious Phenomena for Simple Channels  

E-print Network

Mutual Information, Synergy and Some Curious Phenomena for Simple Channels I. Kontoyiannis Div@dam.brown.edu B. Lucena Division of Computer Science UC­Berkeley, Soda Hall Berkeley, CA 94720, USA Email: lucena connection with the information­theoretic notion of ``synergy,'' which has received a lot of attention

Kontoyiannis, Ioannis

308

Mutual Information, Synergy and Some Curious Phenomena for Simple Channels  

E-print Network

Mutual Information, Synergy and Some Curious Phenomena for Simple Channels I. Kontoyiannis Div@dam.brown.edu B. Lucena Division of Computer Science UC-Berkeley, Soda Hall Berkeley, CA 94720, USA Email: lucena with the information-theoretic notion of "synergy," which has received a lot of attention in the neuroscience

Kontoyiannis, Ioannis

309

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

310

VARIATION IN PUBERTY PHENOMENA IN INBRED GILTS x  

Microsoft Academic Search

LARGE proportion of the pigs produced each year is farrowed by gilts. In spite of this, very little information is available on puberty phenomena in swine. The factors influencing age at puberty probably have been studied more extensively in the rat than in any other mammal. Hereditary differences in age at vaginal opening in different strains of rats have been

A. C. WARNICK; E. L. WIcx; L. E. CASIDA; A. B. CHAPMAN

2010-01-01

311

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

312

Searches for New Phenomena in cdf Luca Scodellaro  

E-print Network

Searches for New Phenomena in cdf Luca Scodellaro Padova University & INFN for the CDF Photons Tau Leptons Luca Scodellaro for the CDF collaboration 2 #12;LaThuile - March 9th-15th, 2003.5) Renewed trigger and daq systems Luca Scodellaro for the CDF collaboration 3 #12;LaThuile - March 9th-15th

Fermilab

313

Electromagnetically and Thermally Driven Flow Phenomena in Electroslag Welding  

E-print Network

) Electromagnetically and Thermally Driven Flow Phenomena in Electroslag Welding A. H. DILAWARI, J for the Electroslag Welding Process. In the formulation, allowance has been made {or both etee- tromagnetic and b in the use of electroslag welding (ESW), particularly for the construction of thick walled pressure vessels

Eagar, Thomas W.

314

1 INTRODUCTION Many macroscopic phenomena of granular media are  

E-print Network

1 INTRODUCTION Many macroscopic phenomena of granular media are dealt with through element testing's need for a constitutive model. However there is often doubt concerning the dependence for il- lustration; an element test and a physical model. 2 IMAGING TECHNIQUES 2.1 Close-up digital

Bolton, Malcolm

315

Synchronization phenomena for coupled delay-line oscillators  

E-print Network

Synchronization phenomena for coupled delay-line oscillators Carmen Chicone Z. C. Feng June 25, 2004 Abstract Two coupled delay-line oscillators are modeled by a system of de- lay differential equations, and their oscillations are analyzed by reduc- ing the delay equations to a system of ordinary

Chicone, Carmen

316

New Phenomena in NC Field Theory and Emergent Spacetime Geometry  

SciTech Connect

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

Ydri, Badis [Institute of Physics BM Annaba University, BP 12-23000-Annaba (Algeria)

2010-10-31

317

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

318

Thermal conduction phenomena in VLSI circuits and systems  

Microsoft Academic Search

Continuous scaling of very large scale integrated (VLSI) circuits poses severe thermal problems, which have major implications for performance and reliability in high-performance planar (2-D) integrated circuits (ICs) and emerging circuit architectures, such as vertically integrated (3-D) ICs. This dissertation aims to understand the thermal conduction phenomena from the fundamental material level to the system level and provides guidelines to

Sungjun Im

2006-01-01

319

Recent Applications of the Volterra Theory to Aeroelastic Phenomena  

Microsoft Academic Search

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

Walter A. Silva

320

Impact of Depolarization Phenomena on Polarized MIMO Channel Performances  

E-print Network

highlights the impact of de- polarization effect on the MIMO channel capacity for a 4?4 uniform linear-output (MIMO) systems, channel capacity, spatial fading correlation, multi-polarized antenna arrays, depolariImpact of Depolarization Phenomena on Polarized MIMO Channel Performances Nuttapol PRAYONGPUN

Paris-Sud XI, Université de

321

Nonlinear dynamics of drops and bubbles and chaotic phenomena  

Microsoft Academic Search

Nonlinear phenomena associated with the dynamics of free drops and bubbles are investigated analytically, numerically and experimentally. Although newly developed levitation and measurement techniques have been implemented, the full experimental validation of theoretical predictions has been hindered by interfering artifacts associated with levitation in the Earth gravitational field. The low gravity environment of orbital space flight has been shown to

Eugene H. Trinh; L. G. Leal; Z. C. Feng; R. G. Holt

1994-01-01

322

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

2014-07-09

323

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

324

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

325

SATELLITE IMAGING OF TEMPORAL PHENOMENA Because the World is Watching  

E-print Network

SATELLITE IMAGING OF TEMPORAL PHENOMENA Because the World is Watching For Further Information out, providing good approximations to the data actually collected. Detailed analysis of the satellite, and other movement over water. Previously imaged targets rotate with frequencies on the order of 1 Hz

326

Assessment of Relevant Physical Phenomena Controlling Thermal Performance of Nanofluids  

E-print Network

Assessment of Relevant Physical Phenomena Controlling Thermal Performance of Nanofluids Majid thermal conductivity of nanofluids. Through an investigation, a large degree of randomness and scatter has and lower bounds are developed for steady-state conduction in stationary nanofluids. Comparisons between

Bahrami, Majid

327

Quasiperiodic phenomena in the Van der Pol -Mathieu equation  

E-print Network

Quasiperiodic phenomena in the Van der Pol - Mathieu equation F. Veerman and F. Verhulst Department The Van der Pol - Mathieu equation, combining self-excitation and parametric excitation, is analysed near - Mathieu equation to model various engineering problems. The analysis in [1] employs harmonic balance

Verhulst, Ferdinand

328

ORIGINAL PAPER Using descriptions of biological phenomena for idea generation  

E-print Network

2008 ? Springer-Verlag London Limited 2008 Abstract Biomimetic design uses biological phenomena to inspire solutions to engineering problems. While many examples of biomimetic design involved detailed in a larger variety of solutions. Keywords Biomimetic design Á Bioanalogous design Á Design-by-analogy Á Idea

Shu, Lily H.

329

NANOINDENTATION-INDUCED DEFECTINTERFACE INTERACTIONS: PHENOMENA, METHODS AND  

E-print Network

NANOINDENTATION-INDUCED DEFECT±INTERFACE INTERACTIONS: PHENOMENA, METHODS AND LIMITATIONS W. W and produce material instabilities is essential to the accurate measure of ¯ow and fracture by nanoindentation. In particular the elasticity analyses have been shown to work well in the nanoindentation regime for many

Volinsky, Alex A.

330

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

331

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

332

Towards a mesh-free computation of transport phenomena  

Microsoft Academic Search

This paper formulates a computational procedure based on the Trefftz method for the solution of nonlinear transport phenomena. This new unified approach is particularly important when solving coupled, nonlinear, inhomogenous, anisotropic, multiphase, and multifield heat and mass transfer problems. Physical system represents the general transport equation, standing for a broad spectra of mass, energy, momentum, and species transfer problems. This

Boidar arler

2002-01-01

333

Free energy calculations: Applications to chemical and biochemical phenomena  

Microsoft Academic Search

The author will review the applications of free energy calculations employing molecular dynamics or Monte Carlo methods to a variety of chemical and biochemical phenomena. The focus is on the applications of such calculations to molecular solvation, molecular association, macromolecular stability, and enzyme catalysis. The molecules discussed range from monovalent ions and small molecules to proteins and nucleic acids.

Peter. Kollman

1993-01-01

334

Limiting flux phenomena in ultrafiltration of kraft black liquor  

Microsoft Academic Search

Limiting flux phenomena were studied in the ultrafiltration of black liquor. The experiments were carried out using an asymmetric membrane, in a stirred batch cell modified to work on a continuous mode. Polyethylene glycol6000, a standard macromolecule, was used to compare the results. The effects of operating variables (viz., differential pressure, bulk concentration and stir- rer speed) on permeate flux

S. Sridhar; P. K. Bhattacharya

1991-01-01

335

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

336

Dynamic phenomena and human activity in an artificial society  

Microsoft Academic Search

We study dynamic phenomena in a large social network of nearly 3104 individuals who interact in the large virtual world of a massive multiplayer online role playing game. On the basis of a database received from the online game server, we examine the structure of the friendship network and human dynamics. To investigate the relation between networks of acquaintances in

A. Grabowski; N. Kruszewska; R. A. Kosinski

2008-01-01

337

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

338

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

339

Pulsed laser ablation of solids and critical phenomena  

Microsoft Academic Search

We consider the possible manifestations of critical phenomena under pulsed laser ablation (PLA). The mechanism of phase explosion under nanosecond laser ablation is considered and the possibility of estimating the critical temperature from PLA experiments is discussed. A model based on the Euler equations and generalized van der Waals equation is developed to describe rarefaction shock waves (RSW) in near-critical

Nadezhda M Bulgakova; Alexander V Bulgakov; Igor M Bourakov; Natalia A Bulgakova

2002-01-01

340

Breakdown Phenomena of a Vacuum Interrupter after Current Zero  

Microsoft Academic Search

A study on breakdown phenomena in a vacuum interrupter was conducted with the use of a numerical model based on the continuous transition model by Andrews and Varey (1). The vacuum model was validated against test data for the device under consideration. The study aim to find the mechanisms that prompt the breakdown of the interrupter as well as interrupting

Lionel R. Orama

341

A numerical simulation of the phenomena in Be plasma  

Microsoft Academic Search

In this paper, we present the numerical simulation of the Be deposition phenomena using the Thermionic Vacuum Arc (TVA) method. The Be marker layer must be adherent to the substrate and compact to resemble bulk beryllium. Thermionic Vacuum Arc (TVA) is an externally heated cathode arc which can be established in high vacuum condition, in vapors of the anode material.

Camelia Gavrila; Cristian P. Lungu; Ion Gruia

2011-01-01

342

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

343

Analysis of interaction phenomena between liquid jets and materials  

Microsoft Academic Search

The interaction phenomena of high-velocity liquid jets impinging on a material surface have been investigated theoretically and experimentally to gain an understanding of the physical mechanisms involved in material removal by fluidjet machining processes. Experiments were performed to determine conditions under which the liquid jet impacting a solid material will cause material removal and also to delineate possible physical mechanisms

Sang-Wook Kang; T. Reitter; G. Carlson

1995-01-01

344

ON THE RELATION BETWEEN COMPLEX MODES AND WAVE PROPAGATION PHENOMENA  

Microsoft Academic Search

This paper discusses the well-known, but often misunderstood, concept of complex modes of dynamic structures. It shows how complex modes can be interpreted in terms of wave propagation phenomena caused by either localized damping or propagation to the surrounding media. Numerical simulation results are presented for different kinds of structures exhibiting modal and wave propagation characteristics: straight beams, an L-shaped

K. M. AHMIDA; J. R. F. ARRUDA

2002-01-01

345

On the Relation Between Complex Modes and Wave Propagation Phenomena  

Microsoft Academic Search

This paper discusses the well-known, but often misunderstood, concept of complex modes of dynamic structures. It shows how complex modes can be interpreted in terms of wave propagation phenomena caused by either localized damping or propagation to the surrounding media. Numerical simulation results are presented for different kinds of structures exhibiting modal and wave propagation characteristics: straight beams, an L-shaped

K. M. Ahmida; J. R. F. Arruda

2002-01-01

346

Oscillations in stellar atmospheres  

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

347

Sources of atmospheric ammonia  

NASA Technical Reports Server (NTRS)

The information available on factors that influence emissions from the principal societal sources of ammonia to the atmosphere, namely combustion processes, volatilization of farm animal wastes, and volatilization of fertilizers, is reviewed. Emission factors are established for each major source of atmospheric ammonia. The factors are then multiplied by appropriate source characterization descriptors to obtain calculated fluxes of ammonia to the atmosphere on a state-by-state basis for the United States.

Harriss, R. C.; Michaels, J. T.

1982-01-01

348

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

349

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

350

CIRAFellowships in Atmospheric Science  

E-print Network

Oceanic and Atmospheric Administration, Colorado State University and CIRA scientists. Salary, Agricultural Meteorology, Model Evaluation, Economic and Societal Aspects of Weather and Climate For more

Collett Jr., Jeffrey L.

351

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

352

The Laser Atmospheric Wind Sounder (LAWS) Phase 2 Preliminary System Design  

NASA Technical Reports Server (NTRS)

The laser Atmospheric Wind Sounder (LAWS) is intended to measure global wind profiles in the lower and upper troposphere as part of the Earth Observing System (EOS). Global scale wind profiles will lead to a better understanding of large scale circulation processes and climate dynamics, an understanding of mesoscale phenomena, improved numerical weather prediction, and further insights into the coupling of the atmosphere/oceans/biosphere system. Here, details are given of the Phase 2 preliminary design.

Petheram, John C.; Kenyon, David L.; Wissinger, Alan B.; Lawrence, T. Rhidian

1992-01-01

353

Origin and evolution of planetary atmospheres  

NASA Technical Reports Server (NTRS)

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

Lewis, John S.

1992-01-01

354

Clouds in Planetary Atmospheres  

NASA Technical Reports Server (NTRS)

In the terrestrial atmosphere clouds are familiar as vast collections of small water drops or ice cyrstals suspended in the air. The study of clouds touches on many facets of armospheric science. The chemistry of clouds is tied to the chemistry of the surrounding atmosphere.

West, R.

1999-01-01

355

Comparative Planetary Atmospheres  

E-print Network

. All of the planets orbit the Sun in the same sense 4. Planets spin in the same sense as their orbits ? solar for Jupiter to ~40 ? solar for Neptune 8. Separation between planet orbits increases with distanceComparative Planetary Atmospheres 1. Formation and evolution of planets and atmospheres Prof FW

Read, Peter L.

356

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.

Youngman, Betsy; Pennycook, Jean; Huffman, Louise; Dahlman, Luann; Nebraska, Andrill- U.

357

Atmospheric Thermodynamics Composition  

E-print Network

1 Atmospheric Thermodynamics Ch1 Composition Ch2 Laws Ch3 Transfers Ch12 EnergyBalance Ch4 Water Ch Sciences: Atmospheric Thermodynamics Instructor: Lynn Russell, NH343 http #12;2 Review from Ch. 1 · Thermodynamic quantities · Composition · Pressure · Density · Temperature

Russell, Lynn

358

Atmospheric illumination and shadows  

Microsoft Academic Search

The shadow volume algorithm of Frank Crow was reorganized to provide information on the regions of illuminated space in front of each visible surface. This information is used to calculate the extra intensity due to atmospheric scattering, so when the atmosphere is partly in shadow, columns of scattered light will be visible. For efficiency in sorting the shadow edges, the

Nelson L. Max

1986-01-01

359

Dynamics of Atmospheres  

E-print Network

, equatorial waves and super-rotation. · Gas Giant Planets: Jupiter, Saturn, Uranus & Neptune ­ Overview Atmospheres · Mars ­ Overview of the general circulation compared to Earth. Seasonal CO2 cycle and interpolar of atmospheric tides and dust storms. · Slowly-rotating planets: Venus & Titan ­ Overview of circulation. Hadley

Read, Peter L.

360

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.

Lambertson, Lori

2007-01-01

361

Advances in atmospheric acoustics  

Microsoft Academic Search

We give a detailed review of developments in atmospheric acoustics of the last decade. These developments include new ways to use refractive effects, studies of phase and amplitude fluctuations during propagation of sound along a path, nonlinear effects near high-powered acoustic antennas, problems related to noise, insights into large-scale atmospheric processes gained from infrasound, applications dependent on the Doppler frequency

Edmund H. Brown; Freeman F. Hall

1978-01-01

362

Advances in atmospheric acoustics  

Microsoft Academic Search

A detailed review of developments in atmospheric acoustics of the last decade is given. These developments include new ways to use refractive effects, studies of phase and amplitude fluctuations during propagation of sound along a path, nonlinear effects near high-powered acoustic antennas, problems related to noise, insights into large-scale atmospheric processes gained from infrasound, applications dependent on the Doppler frequency

E. H. Brown; Freeman F. Hall

1978-01-01

363

PANS IN THE ATMOSPHERE  

EPA Science Inventory

The types of PANs and PBzN's present or possibly present in the ambient atmosphere are discussed. iological activities of the PAN's and PBzN's are briefly considered. he concentration and composition of PANs in the atmosphere are discussed and calculations made of the production ...

364

6, 38453882, 2006 Atmospheric  

E-print Network

with the product of gaseous sulphuric acid and ammonia concentrations. This indicates that besides gaseousACPD 6, 3845­3882, 2006 Atmospheric sulphuric acid and aerosol formation S.-L. Sihto et al. Title Chemistry and Physics Discussions Atmospheric sulphuric acid and aerosol formation: implications from

Paris-Sud XI, Université de

365

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

366

The atmosphere below  

NASA Astrophysics Data System (ADS)

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.

1992-05-01

367

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 ...

Magnuson, Miss

2009-12-07

368

Numerical simulation on snow melting phenomena by CIP method  

NASA Astrophysics Data System (ADS)

A numerical scheme based on the C-CUP method to simulate melting phenomena in snow is proposed. To calculate these complex phenomena we introduce the phase change, elastic-plastic model, porous model, and verify each model by using some simple examples. This scheme is applied to a practical model, such as the snow piled on the insulator of electrical transmission line, in which snow is modeled as a compound material composed of air, water, and ice, and is calculated by elastic-plastic model. The electric field between two electrodes is solved by the Poisson equation giving the Joule heating in the energy conservation that eventually leads to snow melting. Comparison is made by changing the fraction of water in the snow to see its effect on melting process for the cases of applied voltage of 50 and 500 kV on the two electrodes.

Mizoe, H.; Yoon, Seong Y.; Josho, M.; Yabe, T.

2001-04-01

369

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

370

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

371

Musical obsessions: a comprehensive review of neglected clinical phenomena.  

PubMed

Intrusive musical imagery (IMI) consists of involuntarily recalled, short, looping fragments of melodies. Musical obsessions are distressing, impairing forms of IMI that merit investigation in their own right and, more generally, research into these phenomena may broaden our understanding of obsessive-compulsive disorder (OCD), which is phenomenologically and etiologically heterogeneous. We present the first comprehensive review of musical obsessions, based on the largest set of case descriptions ever assembled (N=96). Characteristics of musical obsessions are described and compared with normal IMI, musical hallucinations, and visual obsessional imagery. Assessment, differential diagnosis, comorbidity, etiologic hypotheses, and treatments are described. Musical obsessions may be under-diagnosed because they are not adequately assessed by current measures of OCD. Musical obsessions have been misdiagnosed as psychotic phenomena, which has led to ineffective treatment. Accurate diagnosis is important for appropriate treatment. Musical obsessions may respond to treatments that are not recommended for prototypic OCD symptoms. PMID:24997394

Taylor, Steven; McKay, Dean; Miguel, Euripedes C; De Mathis, Maria Alice; Andrade, Chittaranjan; Ahuja, Niraj; Sookman, Debbie; Kwon, Jun Soo; Huh, Min Jung; Riemann, Bradley C; Cottraux, Jean; O'Connor, Kieron; Hale, Lisa R; Abramowitz, Jonathan S; Fontenelle, Leonardo F; Storch, Eric A

2014-08-01

372

High spatial resolution measurements of ram accelerator gas dynamic phenomena  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

373

Modeling of convection phenomena in Bridgman-Stockbarger crystal growth  

NASA Technical Reports Server (NTRS)

Thermal convection phenomena in a vertically oriented Bridgman-Stockbarger apparatus were modeled by computer simulations for different gravity conditions, ranging from earth conditions to extremely low gravity, approximate space conditions. The modeling results were obtained by the application of a state-of-the art, transient, multi-dimensional, completely densimetrically coupled, discrete-element computational model which was specifically developed for the simulation of flow, temperature, and species concentration conditions in two-phase (solid-liquid) systems. The computational model was applied to the simulation of the flow and the thermal conditions associated with the convection phenomena in a modified Germanium-Silicon charge enclosed in a stationary fused-silica ampoule. The results clearly indicated that the gravitational field strength influences the characteristics of the coherent vortical flow patterns, interface shape and position, maximum melt velocity, and interfacial normal temperature gradient.

Carlson, F. M.; Eraslan, A. H.; Sheu, J. Z.

1985-01-01

374

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

375

Multiple-fluid models for plasma wake-field phenomena  

SciTech Connect

In this paper we present various treatments of plasma wake-field phenomena which employ multiple-fluid models. These models generalize the one-dimensional, nonlinear, relativistic single-fluid model which has been used extensively in previous plasma wake-field calculations. Using a two-fluid model, we discuss the interaction of a low-energy continuous electron beam with wake-field-generated plasma waves. The phenomena of continuous-beam modulation and wave period shortening are discussed. The relationship between these effects and the two-stream instability is also examined. Also, using a three-fluid model, effects due to plasma electron temperature in nonlinear plasma wake-fields are examined and compared to previous work. Finally, the consequences of ion motion induced by large-amplitude electron plasma waves are calculated by including the fluid behavior of the ions.

Rosenzweig, J.B. (Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (US))

1989-11-01

376

Critical phenomena: 150 years since Cagniard de la Tour  

E-print Network

Critical phenomena were discovered by Cagniard de la Tour in 1822, who died 150 years ago. In order to mark this anniversary, the context and the early history of his discovery is reviewed. We then follow with a brief sketch of the history of critical phenomena, indicating the main lines of development until the present date. Os fen\\'omenos cr\\'{\\i}ticos foram descobertos pelo Cagniard de la Tour em Paris em 1822. Para comemorar os 150 anos da sua morte, o contexto e a hist\\'oria initial da sua descoberta \\'e contada. Conseguimos com uma descri\\c{c}\\~ao breve da hist\\'oria dos fen\\'emenos cr\\'{\\i}ticos, indicando as linhas principais do desenvolvimento at\\'e o presente.

Bertrand Berche; Malte Henkel; Ralph Kenna

2009-05-12

377

Psychoactive Substances and Paranormal Phenomena: A Comprehensive Review  

E-print Network

This paper investigates the relationship between psychoactive substances and so-called paranormal phenomena falling within the study of parapsychology. It is primarily concerned with extrasensory perception (ESP)telepathy, precognition, and clairvoyanceas well as out-of-body experiences (OBEs) and near-death experiences (NDEs). Psychokinesis (PK), aura vision, encounter experiences, and sleep paralysis only make a very limited contribution to this review as they are seldom related to psychoactive drugs within the parapsychological literature. The paper borrows widely, but by no means exhaustively, from parapsychology as well as transpersonal studies, anthropology, ethnobotany, phytochemistry, psychiatry, psychotherapy, psychopharmacology, and neurobiology, particularly neurochemistry. It is organized into neurochemical models of paranormal experience (section 1), field reports of intentional and spontaneous phenomena incorporating anthropological, historical and clinical cases, and personal accounts (section 2), surveys of paranormal belief and experience (section 3), experimental research (section 4), and a methodological critique of the experimental research with recommendations for further work (section 5).

David Luke; John Smythies; Aldous Huxley; Gordon Wasson; Timothy Leary; Ken Kesey; Duncan Blewett; James Fadiman; Stanislav Grof

378

The effect of music on ketamine induced emergence phenomena.  

PubMed

The purpose of this investigation was to assess the influence of music on emergence phenomena after ketamine anaesthesia. Fifty ASA 1 patients undergoing minor gynaecological procedures were randomly divided into two equal groups. Patients in the treated group were played music of their choice through headphones from 5 min before induction of anaesthesia to 15 min postoperatively. Although the incidence of emergence phenomena was similar in both groups the effects tended to be more pleasant and acceptable in those to whom music was played. The majority of patients in the study group (80%) expressed their willingness to have a similar anaesthetic in the future compared to 52% in the control group (p less than 0.05). PMID:1599073

Kumar, A; Bajaj, A; Sarkar, P; Grover, V K

1992-05-01

379

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

380

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

381

Chaotic phenomena of a periodic ion-acoustic soliton system  

Microsoft Academic Search

Chaotic phenomena of a periodic ion-acoustic solitons system that is composed of a series of ion-acoustic solitons have been observed in a double-plasma device. Periodic ion-acoustic solitons become unstable by the energy gain and energy loss of the solitons, and they become chaotic. Taking account of a pair of solitons in the system, the front soliton gains energy from the

T. Nagasawa

1999-01-01

382

Experimental and computational simulation of in-flight icing phenomena  

NASA Astrophysics Data System (ADS)

This paper reviews experimental and computational methods used for simulation of ice accretion on aircraft flying through icing conditions. Such methods were recently reviewed by the AGARD FDP Working Group 20 and the present paper represents a revised and updated version of parts of the Working Group report. To provide essential background, it begins with a brief physical description of the ice accretion process. Experimental simulations must respect certain similarity requirements or scaling laws if they are to be valid; these requirements are discussed in some detail and in the framework of this discussion, physical phenomena are considered in more detail as well. Techniques and ground-based facilities for experimental simulation of ice-accretion phenomena are then reviewed, followed by a review of techniques and facilities used for flight testing in support of aircraft design and certification for flight in icing conditions. Available instruments for required measurements such as droplet size distribution and liquid water content and for inflight ice detection are briefly described. Computational simulation is becoming increasingly important in aircraft icing work; computational methods are used to simulate ice accretion both with and without iceprotection systems in operation. Computational approaches are outlined and current capabilities are evaluated. Conclusions emerging from the review include the following: rime icing is reasonably well understood and can be adequately simulated for most practical purposes using either experimental or computational methods; some of the physical phenomena known to be important in glaze icing are only poorly understood and there is considerable uncertainty regarding whether or not certain other phenomena are important; consequently, much additional research is required before reduced-scale experimental simulations or computational simulations of glaze icing will be sufficiently accurate and reliable for most practical purposes. Research recommendations are put forward.

Kind, R. J.; Potapczuk, M. G.; Feo, A.; Golia, C.; Shah, A. D.

1998-07-01

383

Relaxation phenomena in lithium-ion-insertion cells  

Microsoft Academic Search

Relaxation phenomena in lithium-ion-insertion cells are modeled. Simulation results are presented for a dual lithium-ion-insertion cell and for a cell using a lithium-foil negative electrode. A period of relaxation after a charge or discharge can cause appreciable changes in the distribution of material in the insertion electrodes. Local concentration cells in the solution phase and an open-circuit potential that depends

Thomas F. Fuller; M. Doyle; J. S. Newman

1994-01-01

384

Interfacial Phenomena: Linking Atomistic and Molecular Level Processes  

SciTech Connect

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

Jay A Brandes

2009-09-23

385

Popcorn phenomena in a ball grid array package  

Microsoft Academic Search

For the purpose of studying popcorn phenomena, plastic ball grid array packages with 119 I\\/O's were tested under the pre-conditioning test conditions. Observations using scanning acoustic tomography and optical microscopy were carried out to investigate the existence of delaminations and cracks in the package, and the cracking patterns after IR reflow. Package deformations and thermo-mechanical stress distributions in the package

Seung-Ho Ahn; Young-Shin Kwon; Kwang-Jae Shin

1994-01-01

386

The role of spinning electrons in paramagnetic phenomena  

NASA Technical Reports Server (NTRS)

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

Bose, D. M.

1986-01-01

387

Induction Phenomena in Photosynthesis of Isolated Spinach Chloroplasts  

Microsoft Academic Search

IN a number of papers concerning the induction phenomena during photosynthesis1-5 I have determined the interrelationship between time and photo-synthetic intensity as expressed by the photosynthesis time-curve. The sample plants used were mainly various species of moss4. In most cases the rate of photosynthesis was measured in terms of uptake of carbon dioxide ; but in a few cases the

Knud Vejlby

1960-01-01

388

Prediction of fading phenomena in land-satellite communication links  

Microsoft Academic Search

This paper addresses the problem of prediction of probability of successful radio communication of any mobile or stationary subscriber located in areas of service such as complex urban environments characterized by nonline-of-sight propagation conditions, which limit GPS, Low Earth Orbit, and Medium Earth Orbit services in land-satellite communications. It presents a self-consistent physical-statistical approach for predicting fading phenomena usually occurring

N. Blaunstein; Y. Cohen; M. Hayakawa

2010-01-01

389

Natural hazard phenomena and mitigation -- 1996. PVP-Volume 330  

SciTech Connect

This volume contains paper to be presented in five sessions under the title Natural Hazard Phenomena and Mitigation at the 1996 Joint ASME/ICPVT Pressure vessel and Piping Conference held July 21--26, 1996 in Montreal, Quebec, Canada. Three areas are presented in this volume: seismic design and design criteria, impact and dynamic load designs, and structural designs. Papers have been processed separately for inclusion on the data base.

Chang, S.J. [ed.] [Oak Ridge National Lab., TN (United States); Wang, C.Y. [ed.] [Argonne National Lab., IL (United States); Chen, W.W. [ed.] [Westinghouse Hanford Co., Richland, WA (United States); Mok, G.C. [ed.] [Lawrence Livermore National Lab., CA (United States); Lin, C.W. [ed.

1996-12-01

390

Defluidization phenomena during the pyrolysis of two plastic wastes  

Microsoft Academic Search

A couple of commercially available packaging-derived fuels, both obtained as a result of mono-material recycling programs of polyethylene (PE) and polyethylene terephthalate (PET), were fed in a laboratory scale bubbling fluidized-bed reactor, made of quartz. The effect of the main operating variables (bed solids hold-up, inert material size, fluidizing velocity, plastics feed rate) on the agglomeration and the defluidization phenomena

Umberto Arena; Maria Laura Mastellone

2000-01-01

391

The 29th International Conference on Phenomena in Ionized Gases  

Microsoft Academic Search

The 29th International Conference on Phenomena in Ionized Gases (ICPIG) was held in Cancn, Mexico, on 1217 July, 2009, under the sponsorship of the Universidad Nacional Autnoma de Mexico, UNAM, the Universidad Autnoma Metropolitana, UAM, and the International Union of Pure and Applied Physics (IUPAP).ICPIG, founded in 1953, has since been held biennally, and nowadays it covers both fundamental and

J de Urquijo

2010-01-01

392

Unraveling interfacial jetting phenomena induced by focused surface acoustic waves  

Microsoft Academic Search

Surface acoustic waves have been known to be able to drive fluid jetting phenomena, though the underlying physical mechanism has remained unclear. In a setup designed to reliably jet small fluid droplets, a pair of focused single-phase unidirectional transducers were placed facing each other along the x-axis of a 128Y-X lithium niobate substrate. Driving both transducers at the same time,

James Friend; Ming Tan; Leslie Yeo

2009-01-01

393

Clinical correlation between hypercoagulability and thrombo-embolic phenomena  

Microsoft Academic Search

Clinical correlation between hypercoagulability and thrombo-embolic phenomena. A study of the coagulolytic balance as well as platelet aggregation was carried out in 64 nephrotic patients. The data were correlated, in a prospective attempt, with the clinical demonstration of thrombo-embolic events. Activating factors (factors I, VIIIc, VIIIr:Ag) were increased as well as certain clotting inhibitors, ?-1-antitrypsin and ?-2-macroglobulin. There was a

Alain Robert; Michel Olmer; Jean Sampol; Jean-E Gugliotta; Paul Casanova

1987-01-01

394

Macro-micro Interlocked Simulation for Multiscale Phenomena  

Microsoft Academic Search

A new methodology for the simulation of multiscale pro-cesses, called Macro-Micro Interlocked (MMI) Simulation, is introduced.\\u000a The MMI simulation is carried out by the two-way connection of different numerical models, which may handle macroscopic and\\u000a microscopic dynamics, respectively. The MMI simulation are applied to several multiscale phenomena, for instance, cloud formation,\\u000a gas detonation, and plasma dynamics. The results indicate that

Kanya Kusano; Shigenobu Hirose; Toru Sugiyama; Shinichiro Shima; Akio Kawano; Hiroki Hasegawa

2007-01-01

395

A data-driven visual simulation of fire phenomena  

Microsoft Academic Search

In order to simulate and visualize natural phenomena, especially fluid behavior such as smoke and fire, many novel studies have recently been conducted. Usually these methods use CFD (computational fluid dynamics), which calculate Navier-Stokes equations in real-time to generate realistic fluid motion and interactions, as well as high-performance GPU technologies. We proposed a new approach to the visual simulation of

Moohyun Cha; Jaikyung Lee; Byungil Choi; Hyokwang Lee; Soonhung Han

2009-01-01

396

Investigation of mesoscale meteorological phenomena as observed by geostationary satellite  

NASA Technical Reports Server (NTRS)

Satellite imagery plus conventional synoptic observations were used to examine three mesoscale systems recently observed by the GOES-EAST satellite. The three systems are an arc cloud complex (ACC), mountain lee wave clouds and cloud streets parallel to the wind shear. Possible gravity-wave activity is apparent in all three cases. Of particular interest is the ACC because of its ability to interact with other mesoscale phenomena to produce or enhance convection.

Brundidge, K. C.

1982-01-01

397

Possible relationships between solar activity and meteorological phenomena  

NASA Technical Reports Server (NTRS)

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

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

1975-01-01

398

Towards predicting weld metal microstructure from fundamentals of transport phenomena  

SciTech Connect

Heat transfer and fluid flow during manual metal arc welding Of low alloy steels were investigated by solving the equations of conservation of mass, momentum and energy in three dimensions. Calculated cooling rates were coupled with an existing phase transformation model to predict the microstructure in low alloy steel welds. The computed results were found to be in good agreement with experimentally observed microstructures. The agreement indicates significant promise for predicting spatial distribution of weld metal microstructure from the fundamentals of transport phenomena.

Mundra, K.; DebRoy, T.; Babu, S.S. [Pennsylvania State Univ., University Park, PA (United States); David, S.A. [Oak Ridge National Lab., TN (United States); Paul, A.J. [Concurrent Technologies Corp., Johnstown, PA (United States)

1995-06-01

399

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

SciTech Connect

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

Not Available

1993-12-31

400

Analysis of interaction phenomena between liquid jets and materials [preprint  

Microsoft Academic Search

The interaction phenomena of high-velocity liquid jets impinging on a material surface have been investigated theoretically and experimentally to understand the physics of material removal by jet-machining processes. Experiments were performed to delineate conditions under which liquid jet impacts will cause mass removal and to determine optimum jet-cutting conditions. Theoretical analyses have also been carried out to study the effects

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

1995-01-01

401

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 ...

402

Preface: cardiac control pathways: signaling and transport phenomena.  

PubMed

Signaling is part of a complex system of communication that governs basic cellular functions and coordinates cellular activity. Transfer of ions and signaling molecules and their interactions with appropriate receptors, transmembrane transport, and the consequent intracellular interactions and functional cellular response represent a complex system of interwoven phenomena of transport, signaling, conformational changes, chemical activation, and/or genetic expression. The well-being of the cell thus depends on a harmonic orchestration of all these events and the existence of control mechanisms that assure the normal behavior of the various parameters involved and their orderly expression. The ability of cells to sustain life by perceiving and responding correctly to their microenvironment is the basis for development, tissue repair, and immunity, as well as normal tissue homeostasis. Natural deviations, or human-induced interference in the signaling pathways and/or inter- and intracellular transport and information transfer, are responsible for the generation, modulation, and control of diseases. The present overview aims to highlight some major topics of the highly complex cellular information transfer processes and their control mechanisms. Our goal is to contribute to the understanding of the normal and pathophysiological phenomena associated with cardiac functions so that more efficient therapeutic modalities can be developed. Our objective in this volume is to identify and enhance the study of some basic passive and active physical and chemical transport phenomena, physiological signaling pathways, and their biological consequences. PMID:18375571

Sideman, Samuel

2008-03-01

403

Computer modelling of nanoscale diffusion phenomena at epitaxial interfaces  

NASA Astrophysics Data System (ADS)

The present study outlines an important area in the application of computer modelling to interface phenomena. Being relevant to the fundamental physical problem of competing atomic interactions in systems with reduced dimensionality, these phenomena attract special academic attention. On the other hand, from a technological point of view, detailed knowledge of the fine atomic structure of surfaces and interfaces correlates with a large number of practical problems in materials science. Typical examples are formation of nanoscale surface patterns, two-dimensional superlattices, atomic intermixing at an epitaxial interface, atomic transport phenomena, structure and stability of quantum wires on surfaces. We discuss here a variety of diffusion mechanisms that control surface-confined atomic exchange, formation of alloyed atomic stripes and islands, relaxation of pure and alloyed atomic terraces, diffusion of clusters and their stability in an external field. The computational model refines important details of diffusion of adatoms and clusters accounting for the energy barriers at specific atomic sites: smooth domains, terraces, steps and kinks. The diffusion kinetics, integrity and decomposition of atomic islands in an external field are considered in detail and assigned to specific energy regions depending on the cluster stability in mass transport processes. The presented ensemble of diffusion scenarios opens a way for nanoscale surface design towards regular atomic interface patterns with exotic physical features.

Michailov, M.; Ranguelov, B.

2014-05-01

404

Assessing Decreased Sensation and Increased Sensory Phenomena in Diabetic Polyneuropathies  

PubMed Central

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

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

2013-01-01

405

NASA's Upper Atmosphere Research Program (UARP) and Atmospheric Chemistry Modeling and Analysis Program (ACMAP): Research Summaries 1997-1999  

NASA Technical Reports Server (NTRS)

Under the mandate contained in the FY 1976 NASA Authorization Act, the National Aeronautics and Space Administration (NASA) has developed and is implementing a comprehensive program of research, technology development, and monitoring of the Earth's upper atmosphere, with emphasis on the upper troposphere and stratosphere. This program aims at expanding our chemical and physical understanding to permit both the quantitative analysis of current perturbations as well as the assessment of possible future changes in this important region of our environment. It is carried out jointly by the Upper Atmosphere Research Program (UARP) and the Atmospheric Chemistry Modeling and Analysis Program (ACMAP), both managed within the Research Division in the Office of Earth Science at NASA. Significant contributions to this effort have also been provided by the Atmospheric Effects of Aviation Project (AEAP) of NASA's Office of Aero-Space Technology. The long-term objectives of the present program are to perform research to: understand the physics, chemistry, and transport processes of the upper troposphere and the stratosphere and their control on the distribution of atmospheric chemical species such as ozone; assess possible perturbations to the composition of the atmosphere caused by human activities and natural phenomena (with a specific emphasis on trace gas geographical distributions, sources, and sinks and the role of trace gases in defining the chemical composition of the upper atmosphere); understand the processes affecting the distributions of radiatively active species in the atmosphere, and the importance of chemical-radiative-dynamical feedbacks on the meteorology and climatology of the stratosphere and troposphere; and understand ozone production, loss, and recovery in an atmosphere with increasing abundances of greenhouse gases. The current report is composed of two parts. Part 1 summarizes the objectives, status, and accomplishments of the research tasks supported under NASA UARP and ACMAP in a document entitled, Research Summaries 1997- 1999. Part 2 is entitled Present State of Knowledge of the Upper Atmosphere 1999 An Assessment Report.

Kurylo, M. J.; DeCola, P. L.; Kaye, J. A.

2000-01-01

406

Microbiology and atmospheric processes: an upcoming era of research on bio-meteorology  

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.

2008-01-01

407

ACCURATE AND EFFICIENT LONG-RANGE LIGHTNING GEO-LOCATION USING A VLF RADIO ATMOSPHERIC  

E-print Network

ACCURATE AND EFFICIENT LONG-RANGE LIGHTNING GEO-LOCATION USING A VLF RADIO ATMOSPHERIC WAVEFORM and locate lightning flashes for a broad range of commercial and scientific applications, includ- ing air and magnetospheric electrical phenomena. These lightning detection systems have varying degrees of coverage area

408

Areas where solar-terrestrial coupling may influence or be influenced by the middle atmosphere  

NASA Technical Reports Server (NTRS)

The nature of the wave interactions, particularly those induced by transient solar and geomagnetic phenomena is discussed. Solar activity which includes modulations of galactic cosmic ray flux reaching Earth is discussed. Coupling processes involving charged particles and atmospheric electric structure are presented.

Goldberg, R. A.

1979-01-01

409

Atmospheric monitoring of Mars by the Mars Orbiter Camera on Mars global surveyor  

Microsoft Academic Search

MOC wide-angle cameras routinely produce daily global maps of Mars in two colors at ~7.5 km\\/pixel resolution. These images have been used to study several seasonal phenomena linked to atmospheric processes and condensate cycles: dust storms, clouds, and polar recessions. Preliminary results of observations of polar caps and dust storms are presented here.

P. B. James; B. A. Cantor

2002-01-01

410

Atmospheric monitoring of Mars by the Mars Orbiter Camera on Mars global surveyor  

Microsoft Academic Search

MOC wide-angle cameras routinely produce daily global maps of Mars in two colors at ?7.5 km\\/pixel resolution. These images have been used to study several seasonal phenomena linked to atmospheric processes and condensate cycles: dust storms, clouds, and polar recessions. Preliminary results of observations of polar caps and dust storms are presented here.

P. B. James; B. A. Cantor

2002-01-01

411

Atmospheric Loadings, Concentrations and Visibility Associated with Sandstorms: Satellite and Meteorological Analysis  

Microsoft Academic Search

This Korea-China study monitored the phenomena of sandstorms and significant dustfall (SD) from 1997 to 2000. The analysis of our data included ground measurements of dust concentration, visibility, satellite imagery, aircraft and lidar observations. In addition, an estimation of atmospheric loadings and a studyon the relationship between dust concentrations and visibilitywere carried out. The movement and invasion of dust clouds

Y. S. Chung; H. S. Kim; K. H. Park; J. G. Jhun; S. J. Chen

2003-01-01

412

Effects of Sandstorms and Explosion-Generated Atmospheric Dust on Radio Propagation.  

National Technical Information Service (NTIS)

Suspended particulate matter in the atmosphere, generated by natural phenomena such as dust and sandstorms or by man-made near-surface explosions, has been suspected as a cause of microwave and millimeter-wave communications systems outages. An analysis c...

R. P. Rafuse

1981-01-01

413

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

414

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

415

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

416

Study of the response of the cosmic ray muon flux to nonstationary processes in the Earths atmosphere  

Microsoft Academic Search

The results of the study of the correlation between dynamic atmospheric phenomena and cosmic ray muon flux variations are\\u000a presented. The results of the long-term experiment on continuous measurements of spatioangular variations of the muon flux\\u000a using the URAGAN muon hodoscope are considered. It was shown that the correlation between weather phenomena and changes in\\u000a the angular distribution of the

A. S. Mikhailenko; A. N. Dmitrieva; A. A. Petrukhin; D. A. Timashkov; V. V. Shutenko; I. I. Yashin

2010-01-01

417

Atmospheric,OceanicandSpaceSciences Atmospheric, Oceanic & Space Sciences  

E-print Network

/Thermosphere Physics Planetary Magnetospheres Solar & Heliospheric Physics Space Weather Aeronomy For Faculty involved Atmospheric & Space Science Research Areas Numerical Methods & Scientific Computing Planetary Atmospheres

Eustice, Ryan

418

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

419

Evolution of Atmospheres  

SciTech Connect

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

Hanson, B.

1993-02-12

420

Atmospheric refraction: a history  

NASA Astrophysics Data System (ADS)

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

Lehn, Waldemar H.; van der Werf, Siebren

2005-09-01

421

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

422

The Puerto Rico Weather Camp 2012 is a summer experience hosted by the NOAA Center for Atmospheric Sciences at UPR Mayagez (UPRM) and co-sponsored by the  

E-print Network

The Puerto Rico Weather Camp 2012 is a summer experience hosted by the NOAA Center for Atmospheric about diverse topics including the complex tropical weather and climate phenomena, the atmosphere observation, and many others. Participants also get to interact with scientists, National Weather Service

Gilbes, Fernando

423

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

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

424

Hypervelocity atmospheric flight: Real gas flow fields  

NASA Technical Reports Server (NTRS)

Flight in the atmosphere is examined from the viewpoint of including real gas phenomena in the flow field about a vehicle flying at hypervelocity. That is to say, the flow field is subject not only to compressible phenomena, but is dominated by energetic phenomena. There are several significant features of such a flow field. Spatially, its composition can vary by both chemical and elemental species. The equations which describe the flow field include equations of state and mass, species, elemental, and electric charge continuity; momentum; and energy equations. These are nonlinear, coupled, partial differential equations that were reduced to a relatively compact set of equations of a self-consistent manner (which allows mass addition at the surface at a rate comparable to the free-stream mass flux). The equations and their inputs allow for transport of these quantities relative to the mass-averaged behavior of the flow field. Thus transport of mass by chemical, thermal, pressure, and forced diffusion; transport of momentum by viscosity; and transport of energy by conduction, chemical considerations, viscosity, and radiative transfer are included. The last of these complicate the set of equations by making the energy equation a partial integrodifferential equation. Each phenomenon is considered and represented mathematically by one or more developments. The coefficients which pertain are both thermodynamically and chemically dependent. Solutions of the equations are presented and discussed in considerable detail, with emphasis on severe energetic flow fields. For hypervelocity flight in low-density environments where gaseous reactions proceed at finite rates, chemical nonequilibrium is considered and some illustrations are presented. Finally, flight where the flow field may be out of equilibrium, both chemically and thermodynamically, is presented briefly.

Howe, John T.

1990-01-01

425

Hypervelocity atmospheric flight: Real gas flow fields  

NASA Technical Reports Server (NTRS)

Flight in the atmosphere is examined from the viewpoint of including real gas phenomena in the flow field about a vehicle flying at hypervelocity. That is to say, the flow field is subject not only to compressible phenomena, but is dominated by energetic phenomena. There are several significant features of such a flow field. Spatially, its composition can vary by both chemical and elemental species. The equations which describe the flow field include equations of state and mass, species, elemental, and electric charge continuity; momentum; and energy equations. These are nonlinear, coupled, partial differential equations that have been reduced to a relatively compact set of equations in a self-consistent manner (which allows mass addition at the surface at a rate comparable to the free-stream mass flux). The equations and their inputs allow for transport of these quantities relative to the mass-average behavior of the flow field. Thus transport of mass by chemical, thermal, pressure, and forced diffusion; transport of momentum by viscosity; and transport of energy by conduction, chemical considerations, viscosity, and radiative transfer are included. The last of these complicate the set of equations by making the energy equations a partial integrodifferential equation. Each phenomenon is considered and represented mathematically by one or more developments. The coefficients which pertain are both thermodynamically and chemically dependent. Solutions of the equations are presented and discussed in considerable detail, with emphasis on severe energetic flow fields. Hypervelocity flight in low-density environments where gaseous reactions proceed at finite rates chemical nonequilibrium is considered, and some illustrations are presented. Finally, flight where the flow field may be out of equilibrium, both chemically and thermodynamically, is presented briefly.

Howe, John T.

1989-01-01

426

Heterogeneous atmospheric chemistry  

NASA Technical Reports Server (NTRS)

The present conference on heterogeneous atmospheric chemistry considers such topics concerning clusters, particles and microparticles as common problems in nucleation and growth, chemical kinetics, and catalysis, chemical reactions with aerosols, electron beam studies of natural and anthropogenic microparticles, and structural studies employing molecular beam techniques, as well as such gas-solid interaction topics as photoassisted reactions, catalyzed photolysis, and heterogeneous catalysis. Also discussed are sulfur dioxide absorption, oxidation, and oxidation inhibition in falling drops, sulfur dioxide/water equilibria, the evidence for heterogeneous catalysis in the atmosphere, the importance of heterogeneous processes to tropospheric chemistry, soot-catalyzed atmospheric reactions, and the concentrations and mechanisms of formation of sulfate in the atmospheric boundary layer.

Schryer, D. R.

1982-01-01

427

Students 'Weigh' Atmospheric Pollution.  

ERIC Educational Resources Information Center

Describes a procedure developed by students that measures the mass concentration of particles in a polluted urban atmosphere. Uses a portable fan and filters of various materials. Compares students' data with official data. (DDR)

Caporaloni, Marina

1998-01-01

428

Institute of Space Atmospheric  

E-print Network

Committee 5 Research Programs Planetary Astronomy Atmospheric Dynamics Magnetosphere/Ionosphere Interactions Ionospheric Physics Aeronomy Research G.R. Davis A.H. Manson G.J. Sofko, A.V. Koustov A.V. Koustov, G

Saskatchewan, University of

429

Atmospheric optical calibration system  

DOEpatents

An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions.

Hulstrom, Roland L. (Bloomfield, CO); Cannon, Theodore W. (Golden, CO)

1988-01-01

430

Atmospheric optical calibration system  

DOEpatents

An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions. 7 figs.

Hulstrom, R.L.; Cannon, T.W.

1988-10-25

431

Atmospheric Chemistry (Program Description)  

NSF Publications Database

... species; the sources and sinks of important trace gases and aerosols; the aqueous-phase atmospheric ... methods for measuring the concentrations of trace species and their fluxes into and out of the ...

432

CSIRO Atmospheric Research  

NSDL National Science Digital Library

The homepage for CSIRO Atmospheric Research, which is devoted "to conduct world-class research into the atmospheric environment and provide advice and applications for the benefit of Australia." Visitors have access to many reports written by the staff on topics such as Climate Modeling and Applications and Air Quality Modeling and Dispersion. Scientists interested in remote sensing can download CalWatch: Calibration Status of the NOAA AVHRR Solar Reflectance Channels: CalWatch Revison 1, a report that discusses results of research dealing with the operational calibration of the AVHRR data sets. Using JAVA, users can download Weatherwall, which demonstrates how to incorporate technologies of real-time data gathering and data management. Students can read about ozone depletion and El Nino events. All can check out the atmospheric forecasts for Victoria and Melbourne. With lots of information and many reports available; researchers, students, and those interested in Australia's atmosphere should check out this valuable site.

433

Exploring Planetary Atmospheres  

NASA Astrophysics Data System (ADS)

The past decade has been an exciting time to study atmospheres. Fundamental studies of Earth's general circulation and hydrological cycle have been stimulated by questions about past climates and the future impacts of humankind's activities. Long-term spacecraft and Earth-based observations of solar system planets have reinvigorated the study of comparative planetary climatology. The explosion in discoveries of planets outside our solar system has made atmospheric science integral to understanding the diversity of our solar system and the potential habitability of planets outside it. Thus, the AGU Chapman Conference: Crossing the Boundaries in Planetary AtmospheresFrom Earth to Exoplanets, gathered Earth, solar system, and exoplanet scientists to share experiences, insights, and challenges from their individual disciplines and to discuss areas in which thinking broadly might enhance scientists' fundamental understanding of how atmospheres work.

Simon-Miller, Amy A.; Del Genio, Anthony D.

2013-11-01

434

Our Changing Atmosphere.  

ERIC Educational Resources Information Center

Summarizes what is known about two major variables involved in certain types of chemical pollution that seem to be changing the structure of the Earth's atmosphere. Discusses the greenhouse effect and the ozone layer. (TW)

Clearing, 1988

1988-01-01

435

Planetary Science (mostly atmospheres)  

E-print Network

Planetary Science (mostly atmospheres) at Boston University Paul Withers withers@bu.edu Planetary Science Decadal Survey Town Hall Meeting Boston University 2011.03.26 #12;Selected people Supriya John

Withers, Paul

436

8, 10691088, 2008 Atmospheric  

E-print Network

Discussion EGU Abstract Smog chamber/FTIR techniques were used to study the products and mechanisms of OH the atmospheric oxi- dation products of trans-CF3CH=CHF. Specifically, smog chamber/FTIR techniques were used

Boyer, Edmond

437

Electrical coupling between the lower atmosphere and the ionosphere  

NASA Technical Reports Server (NTRS)

The evidence for interactions between the ionosphere and troposphere is reviewed as a first step in establishing the role of electrical coupling between two regions. Upward processes appear to include the transfer of energy through gravity waves, or through the transmittance of VLF radio waves induced by lightning. In each case, the excitation of the upper atmosphere by tropospheric sources can stimulate feedback processes returning to the troposphere. Downward coupling involves changes in the global and local electrical structure of the atmosphere, and is often induced by solar activity. These effects are more direct and may possibly bypass the stratosphere. The responses in the atmospheric circuit to local changes are nearly instantaneous, and therefore are looked on with promise for possible influences on weather systems. Emerging experimental evidence indicates that atmospheric electric fields, especially at high latitudes and in the upper atmosphere, are responsive to solar and geomagnetic phenomena. Corpuscular radiations are known to strongly enhance the local atmospheric electrical conductivity and ionizations at stratospheric and mesospheric altitudes. Theories postulate that the electric field perturbations regulated by solar activity may be responsibile for the observed statistical correlations between solar activity and thunderstorms.

Goldberg, R. A.

1981-01-01

438

Seismic waves in the atmosphere and oceans  

NASA Astrophysics Data System (ADS)

We developed a new method to calculate normal modes of the earth and planets. It can treat anelasticity directly as imaginary parts of elastic constants and leaky modes due to the open boundary condition set at the upper atmosphere. The eigenvalue problem is described in complex numbers. It is similar to the Henyey type relaxation method used in solar seismology but a different method. In our method, the complex eigenvalue problem of a large system is reduced to an eigenvalue problem of a quite small size matrix. The eigenvalue of the small problem is a correction of an assumed complex eigenfrequency and components of the eigenvector are values of eigenfunctions at the outer boundary. Starting from an arbitrary complex frequency around the eigenfrequency of a target mode, we can arrive there within, at most, a dozen of steps of iterative calculations. Numerical examples show good behavior of the convergence to complex eigenfrequencies. Even for a model with an atmosphere in which the fundamental spheroidal mode 0S29 and the fundamental acoustic mode 0P29 nearly degenerate, we can easily reach the eigenfrequency of 0S29 and distinguish it from that of 0P29 without any confusion. In addition to the efficiency in the convergence to the eigenfrequencies, numerical tests show strong numerical stability of the method. For those reasons, we propose the method as an efficient way in calculating synthetic sesimograms, barograms and ionograms for recently observed phenomena relating with coupling between the solid earth, the oceans and the atmosphere. Using this method, we show some examples of synthetic seismic waves which are sum of normal modes along Rayleigh branch and Tsunami branch excited by large earthquakes. In paticular, we focus on wave fields of Rayleigh and Tsunami waves in the atmosphere.

Kobayashi, N.

2006-12-01

439

Study of atmospheric dynamics  

NASA Technical Reports Server (NTRS)

In order to better understand the dynamics of the global atmosphere, a data set of precision temperature measurements was developed using the NASA built Microwave Sounding Unit. Modeling research was carried out to validate global model outputs using various satellite data. Idealized flows in a rotating annulus were studied and applied to the general circulation of the atmosphere. Dynamic stratospheric ozone fluctuations were investigated. An extensive bibliography and several reprints are appended.

Mcnider, Richard T.; Christy, John R.; Cox, Gregory N.

1993-01-01

440

Atmospheric Corrections in Coastal Altimetry  

NASA Astrophysics Data System (ADS)

The range measurements from the altimeter are associated with a large number of geophysical corrections which needs special attention near coasts and the shallow water regions. The corrections due to ionosphere, dry and wet troposphere and that due to sea state are of primary importance in altimetry. Water vapor dominates the wet tropospheric corrections by several factors which is more complex with higher spatio-temporal variations and thus needs a careful attention near coasts. In addition to this rain is one of the major atmospheric phenomena which attenuate the backscatter altimeter measurements which in turn affect the altimeter derived wind and wave measurements. Thus during rain events utmost care should be taken while deriving the altimeter wind speeds and wave heights. The first objective of the present study involves the comparison of the water vapor corrections estimated from radiosonde measurements near the coastal regions with the model estimated corrections applied in the altimeter range measurements. Analysis has been performed for the Coastal Altimeter products provided by the PISTACH to observe these corrections. The second objective is to estimate the rain rate using altimeter backscatter measurements. The differential attenuation of KU band over C band due to rain has been utilized to identify the rain events and to estimate the amount of rain fall. JASON-2 altimeter data during two tropical cyclonic events over Bay of Bengal have been used for this purpose. An attempt is made to compare the estimated rain rate from altimeter measurements with the other available collocated satellite observations like KALPANA and TRMM-TMI. The results are encouraging and can be used to provide valid rain flags in the altimeter products in addition to the radiometer rain flags.

Antonita, Maria; Kumar, Raj

2012-07-01

441

Current status and challenges in optical turbulence simulations in various layers of the Earth's atmosphere  

NASA Astrophysics Data System (ADS)

In this study, we present a brief review on the existing approaches for optical turbulence estimation in various layers of the Earth's atmosphere. The advantages and disadvantages of these approaches are also discussed. An alternative approach, based on mesoscale modeling with parameterized turbulence, is proposed and tested for the simulation of refractive index structure parameter (C2n ) in the atmospheric boundary layer. The impacts of a few atmospheric flow phenomena (e.g., low-level jets, island wake vortices, gravity waves) on optical turbulence are discussed. Consideration of diverse geographic settings (e.g., flat terrain, coastal region, ocean islands) makes this study distinct.

He, Ping; Nunalee, Christopher G.; Basu, Sukanta; Vorontsov, Mikhail A.; Fiorino, Steven T.

2014-10-01

442

78 FR 8202 - Meeting of the Joint ACRS Subcommittees on Thermal Hydraulic Phenomena and Materials, Metallurgy...  

Federal Register 2010, 2011, 2012, 2013

...ACRS) Meeting of the Joint ACRS Subcommittees on Thermal Hydraulic Phenomena and Materials, Metallurgy and Reactor Fuels; Notice of Meeting The Joint ACRS Subcommittees on Thermal Hydraulic Phenomena and Materials, Metallurgy and Reactor...

2013-02-05

443

Environmental Phenomena of the Beaufort Sea Observed During the Leads Experiment.  

National Technical Information Service (NTIS)

This paper describes unique environmental phenomena observed during LEADEX (Leads Experiment), a multidisciplinary investigation staged from an ice camp in the Beaufort Sea during March and April 1992. The paper focuses on phenomena observed by NOAA, DMSP...

R. W. Fett, S. D. Burk, W. T. Thompson, T. L. Kozo

1994-01-01

444

Ordering phenomena in quasi-one-dimensional organic conductors.  

PubMed

Low-dimensional organic conductors could establish themselves as model systems for the investigation of the physics in reduced dimensions. In the metallic state of a one-dimensional solid, Fermi liquid theory breaks down and spin and charge degrees of freedom become separated. But the metallic phase is not stable in one dimension: as the temperature is reduced, the electronic charge and spin tend to arrange themselves in an ordered fashion due to strong correlations. The competition of the different interactions is responsible for which broken-symmetry ground state is eventually realized in a specific compound and which drives the system toward an insulating state. Here, we review the various ordering phenomena and how they can be identified by optic and magnetic measurements. While the final results might look very similar in the case of a charge density wave and a charge-ordered metal, for instance, the physical cause is completely different. When density waves form, a gap opens in the density of states at the Fermi energy due to nesting of the one-dimension Fermi surface sheets. When a one-dimensional metal becomes a charge-ordered Mott insulator, on the other hand, the short-range Coulomb repulsion localizes the charge on the lattice sites and even causes certain charge patterns. We try to point out the similarities and conceptional differences of these phenomena and give an example for each of them. Particular emphasis will be put on collective phenomena that are inherently present as soon as ordering breaks the symmetry of the system. PMID:17479236

Dressel, Martin

2007-07-01

445

Space Commercial Opportunities for Fluid Physics and Transport Phenomena Applications  

NASA Technical Reports Server (NTRS)

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

Gavert, R.

2000-01-01

446

Investigation of transient earth resources phenomena: Continuation study  

NASA Technical Reports Server (NTRS)

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

Goldman, G. C.

1974-01-01

447

Complex branching phenomena in the growth of carbon nanotubes  

NASA Astrophysics Data System (ADS)

We report here the experimental observation of complex branching phenomena in the growth of carbon nanotubes produced under specific arc-discharge conditions. High-resolution transmission electron microscopy (HRTEM) images demonstrate that two or three carbon nanotubes can join together under specific angles in L, Y, and T patterns with saddle surfaces at the junction. Adding to the observation of negative curvature surface in straight-line tubes that change their diameters, we report here negative curved areas that support the topography of a branching structure.

Zhou, Dan; Seraphin, Supapan

1995-06-01

448

Manifestations of quantum gravity in scalar QED phenomena  

SciTech Connect

Quantum gravitational corrections to the effective potential, at the one-loop level and in the leading-log approximation, for scalar quantum electrodynamics with higher-derivative gravity, which is taken as an effective theory for quantum gravity (QG), are calculated. We point out the appearance of relevant phenomena caused by quantum gravity, such as dimensional transmutation, QG-driven instabilities of the potential, QG corrections to scalar-to-vector mass ratios, and curvature-induced phase transitions, whose existence is shown by means of analytical and numerical study.

Elizalde, E. (Center for Advanced Study CEAB, CSIC, Cami de Sta. Barbara, 17300 Blanes (Spain) Department ECM and IFAE, Faculty of Physics, University of Barcelona, Diagonal 647, 08028 Barcelona, Catalonia (Spain)); Odintsov, S.D. (Department ECM and IFAE, Faculty of Physics, University of Barcelona, Diagonal 647, 08028 Barcelona, Catalonia (Spain)); Romeo, A. (Center for Advanced Study CEAB, CSIC, Cami de Sta. Barbara, 17300 Blanes (Spain))

1995-04-15

449

Dialectic and science: Galen, Herophilus and Aristotle on phenomena.  

PubMed

This paper examines the nature of Galen's argument in the De placitis Hippocratis et Platonis, books 2-3, concerned with the location of the psychic functions within the body. To this question Galen applies a coherent set of methodological principles, integrating Aristotelian dialectic and scientific demonstration based on anatomical experiments. Galen disagrees with Aristotle in that he relegates the endoxa from the realm of dialectic to that of rhetoric. His attitude is marked by a distinctive emphasis on perceptible phenomena as the starting point for scientific inquiry. This and other features can be traced back to the Hellenistic scientist Herophilus. PMID:7789113

Tieleman, T

1995-01-01

450

FAST TRACK COMMUNICATION: Ricci flows, wormholes and critical phenomena  

NASA Astrophysics Data System (ADS)

We study the evolution of wormhole geometries under the Ricci flow using numerical methods. Depending on values of initial data parameters, wormhole throats either pinch off or evolve to a monotonically growing state. The transition between these two behaviors exhibits a form of critical phenomena reminiscent of that observed in gravitational collapse. Similar results are obtained for initial data that describe space bubbles attached to asymptotically flat regions. Our numerical methods are applicable to 'matter-coupled' Ricci flows derived from conformal invariance in string theory.

Husain, Viqar; Seahra, Sanjeev S.

2008-11-01

451

Searches for Exotic Phenomena at ATLAS and CMS  

E-print Network

The Large Hadron Collider (LHC) was operated at a center-of-mass energy of $\\sqrt{s}$ = 7 and 8TeV for proton-proton collisions in Run I. The CMS and ATLAS detectors both collected approximately 20 $fb^{-1}$ of 8TeV data in the data taking period. This large dataset collected at an unprecedented energy provides an ideal opportunity to search for new physics. In this paper, a selection of recent results from the ATLAS and CMS Collaborations concerning searches for exotic phenomena are presented. The signal models of these analyses contain heavy resonances, dark matter particles, and long-lived particles.

Sho Maruyama; for the ATLAS; CMS Collaborations

2014-11-02

452

Analyzing simple pendulum phenomena with a smartphone acceleration sensor  

NASA Astrophysics Data System (ADS)

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

Vogt, Patrik; Kuhn, Jochen

2012-10-01

453

Thermomagnetic phenomena in the mixed state of high temperature superconductors  

NASA Technical Reports Server (NTRS)

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

Meilikhov, E. Z.

1995-01-01

454

Theory of separation phenomena in strongly-correlated electron systems  

Microsoft Academic Search

We present a coherent gauge-theoretical interpretation of various possible separation phenomena of strongly-correlated electron\\u000a systems. The typical examples are (i) charge-spin separation (CSS) in the t-J model of high-Tc superconductivity, and (ii)\\u000a particle-flux separation (PFS) in the quantum Hall effect atv=1\\/2. By introducing auxiliary gauge fields, we map the system into an effective U(1) lattice gauge theory. It exhibits a

Ikuo Ichinose; Tetsuo Matsui

1996-01-01

455

Comparative analyses of observations of lunar transient phenomena.  

NASA Technical Reports Server (NTRS)

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

Cameron, W. S.

1972-01-01

456

Analysis of interaction phenomena between liquid jets and materials  

SciTech Connect

The interaction phenomena of high-velocity liquid jets impinging on a material surface have been investigated theoretically and experimentally to gain an understanding of the physical mechanisms involved in material removal by fluidjet machining processes. Experiments were performed to determine conditions under which the liquid jet impacting a solid material will cause material removal and also to delineate possible physical mechanisms of mass removal at optimum jet-cutting conditions. We have also carried out numerical simulations of jet-induced surface pressure rises and of the material deformation and spallation behavior due to multiple droplet impacts. Results obtained from the experiments and theoretical calculations and their physical implications are also discussed.

Kang, Sang-Wook; Reitter, T.; Carlson, G.

1995-02-01

457

Tracking Real-World Phenomena with Smart Dust  

Microsoft Academic Search

\\u000a So-called Smart Dust is envisioned to combine sensing, computing, and wireless communication capabilities in an autonomous,\\u000a dust-grain-sized device. Dense networks of Smart Dust should then be able to unobtrusively monitor real-world processes with\\u000a unprecedented quality and scale. In this paper, we present and evaluate a prototype implementation of a system for tracking\\u000a the location of real-world phenomena (using a toy

Kay Rmer

2004-01-01

458

Pulsed laser ablation of solids and critical phenomena  

NASA Astrophysics Data System (ADS)

We consider the possible manifestations of critical phenomena under pulsed laser ablation (PLA). The mechanism of phase explosion under nanosecond laser ablation is considered and the possibility of estimating the critical temperature from PLA experiments is discussed. A model based on the Euler equations and generalized van der Waals equation is developed to describe rarefaction shock waves (RSW) in near-critical matter. For a near-surface slab of a gold target heated above the critical point and expanding freely in vacuum, the evolution of the RSW has been studied. The possibility of RSW formation in stellar matter is discussed.

Bulgakova, Nadezhda M.; Bulgakov, Alexander V.; Bourakov, Igor M.; Bulgakova, Natalia A.

2002-09-01

459

Dissipation-triggered phenomena in periodic acoustic metamaterials  

NASA Astrophysics Data System (ADS)

In designing a periodic acoustic metamaterial it is possible to have one or more of the constituent material phases to be damped (i.e., lossy/dissipative), for example by using a viscoelastic material such as rubber. The presence of damping results in temporal attenuation of the acoustic/elastic waves as they freely propagate through space in the periodic media. In this work we develop Bloch wave propagation models for damped periodic acoustic metamaterials and study the effects of damping on the dispersion relation. We demonstrate several intriguing phenomena that get triggered due to the presence of inherent dissipation.

Frazier, Michael J.; Hussein, Mahmoud I.

2012-04-01

460

Europa's Atmosphere: Production & Loss  

NASA Astrophysics Data System (ADS)

Europa is embedded not only in the ionized material of the Io plasma torus, but is also surrounded by the material (both ionized and neutral) produced by the interaction of this plasma with the moons surface and atmosphere - as illustrated in the schematic below. Moreover, there are energetic ions and electrons that diffuse inwards from the outer magnetosphere and interact with the moon and surrounding neutral clouds. The multiple components of Europas environment are thought to vary on timescales of hours to weeks and to be strongly coupled. Europas O2 atmosphere is created by ion bombardment of the surface. Earlier studies assumed that the energetic (10s keV) ions were responsible (see review in Smyth and Marconi, 2006). New research (Cassidy et al. 2013) suggests that the thermal ion population of the Io plasma torus produces most of Europas O2. But this cooler population is easily diverted by currents induced in Europas ionosphere and prevented from reaching the surface. This feedback has not been adequately explored. Modelers have historically focused on a single piece of the puzzle; plasma modelers assume a static atmosphere and atmosphere modelers assume static plasma. We are now in a position to consider these new sources of atmosphere and determine how the observed system comes about as well as quantify the timescales and causes of its evolution. This begs the question is Europas atmosphere-magnetosphere interaction self-regulating? We are specifically interested in how the system responds to changes - for example, how does Europas atmosphere change when the inflowing plasma flux increases or decreases? What is the corresponding change in the electrodynamics and diversion of plasma flow around Europa? How much and on what time scale does the extended neutral cloud respond? And what are the consequences for the influx of energetic particles? We model this coupled system to address how each component responds to changes in the other components.

Bagenal, Fran; Cassidy, T.; Dols, V.; Crary, F.

2013-10-01

461

Europa's Atmosphere: Production & Loss  

NASA Astrophysics Data System (ADS)

Europa is embedded not only in the ionized material of the Io plasma torus, but is also surrounded by the material (both ionized and neutral) produced by the interaction of this plasma with the moon's surface and atmosphere. Moreover, there are energetic ions and electrons that diffuse inwards from the outer magnetosphere and interact with the moon and surrounding neutral clouds. The multiple components of Europa's environment are thought to vary on timescales of hours to weeks and to be strongly coupled. Europa's O2 atmosphere is created by ion bombardment of the surface. Earlier studies assumed that the energetic (10s keV) ions were responsible (see review in Smyth and Marconi, 2006). New research (Cassidy et al. 2013) suggests that the 'thermal' ion population of the Io plasma torus produces most of Europa's O2. But this cooler population is easily diverted by currents induced in Europa's ionosphere and prevented from reaching the surface. This feedback has not been adequately explored. Modelers have historically focused on a single piece of the puzzle; plasma modelers assume a static atmosphere and atmosphere modelers assume static plasma. We are now in a position to consider these new sources of atmosphere and determine how the observed system comes about as well as quantify the timescales and causes of its evolution. This begs the question is Europa's atmosphere-magnetosphere interaction self-regulating? We are specifically interested in how the system responds to changes - for example, how does Europa's atmosphere change when the inflowing plasma flux increases or decreases? What is the corresponding change in the electrodynamics and diversion of plasma flow around Europa? How much and on what time scale does the extended neutral cloud respond? And what are the consequences for the influx of energetic particles? We model this coupled system to address how each component responds to changes in the other components.

Bagenal, F.; Cassidy, T. A.; Dols, V.; Crary, F. J.

2013-12-01

462

Impact of large-scale atmospheric refractive structures on optical wave propagation  

NASA Astrophysics Data System (ADS)

Conventional techniques used to model optical wave propagation through the Earth's atmosphere typically as- sume flow fields based on various empirical relationships. Unfortunately, these synthetic refractive index fields do not take into account the influence of transient macroscale and mesoscale (i.e. larger than turbulent microscale) atmospheric phenomena. Nevertheless, a number of atmospheric structures that are characterized by various spatial and temporal scales exist which have the potential to significantly impact refractive index fields, thereby resulting dramatic impacts on optical wave propagation characteristics. In this paper, we analyze a subset of spatio-temporal dynamics found to strongly affect optical waves propagating through these atmospheric struc- tures. Analysis of wave propagation was performed in the geometrical optics approximation using a standard ray tracing technique. Using a numerical weather prediction (NWP) approach, we simulate multiple realistic atmospheric events (e.g., island wakes, low-level jets, etc.), and estimate the associated refractivity fields prior to performing ray tracing simulations. By coupling NWP model output with ray tracing simulations, we demon- strate the ability to quantitatively assess the potential impacts of coherent atmospheric phenomena on optical ray propagation. Our results show a strong impact of spatio-temporal characteristics of the refractive index field on optical ray trajectories. Such correlations validate the effectiveness of NWP models as they offer a more comprehensive representation of atmospheric refractivity fields compared to conventional methods based on the assumption of horizontal homogeneity.

Nunalee, Christopher G.; He, Ping; Basu, Sukanta; Vorontsov, Mikhail A.; Fiorino, Steven T.

2014-10-01

463

Prebreakdown phenomena in mineral oil under step and ac voltage in large-gap divergent fields  

Microsoft Academic Search

This paper presents an experimental study of the propagation of prebreakdown phenomena in transformer oil, in large point-plane gaps (5 to 20 cm), in positive polarity under step and ac voltages. The prebreakdown phenomena are characterized via the simultaneous recordings of transient currents, charges, photocurrents, and high-speed photographs of the emitted light. In these experimental conditions, prebreakdown phenomena in oil

P. Rain; O. Lesaint

1994-01-01

464

Space Science I: Planetary Atmospheres  

E-print Network

Space Science I: Planetary Atmospheres Atmospheric Structure and Transport Origins and Evolution of Planetary Atmospheres Books The New Solar System Chapters 8,9,11,13,15,17,18,20 #12;Space Science I, is crucial and is one goal of this course. #12;Space Science I: Planetary Atmospheres Goals To understand- 1

Johnson, Robert E.

465

Emergent topological phenomena in thin films of pyrochlore iridates.  

PubMed

Because of the recent development of thin film and artificial superstructure growth techniques, it is possible to control the dimensionality of the system, smoothly between two and three dimensions. In this Letter we unveil the dimensional crossover of emergent topological phenomena in correlated topological materials. In particular, by focusing on the thin film of pyrochlore iridate antiferromagnets grown along the [111] direction, we demonstrate that the thin film can have a giant anomalous Hall conductance, proportional to the thickness of the film, even though there is no Hall effect in 3D bulk material. Moreover, in the case of ultrathin films, a quantized anomalous Hall conductance can be observed, despite the fact that the system is an antiferromagnet. In addition, we uncover the emergence of a new topological phase, the nontrivial topological properties of which are hidden in the bulk insulator and manifest only in thin films. This shows that the thin film of correlated topological materials is a new platform to search for unexplored novel topological phenomena. PMID:24996097

Yang, Bohm-Jung; Nagaosa, Naoto

2014-06-20

466

Justifying Condensed Matter Nuclear Phenomena Using Hot Fusion Data  

NASA Astrophysics Data System (ADS)

The selective resonant tunneling model [1] has been successful in describing 6 major fusion cross-section data (d+T, d+D, d+He3, t+T, t+He3, p+D). The new formula needs only 3 parameters; however, it gives much better results than what were given by the 5-parameter formula in NRL Plasma Formulary. It provides an opportunity to find the resonance energy level which is necessary to explain the Condensed Matter Nuclear Phenomena in metal-hydrides. The proton-lithium fusion data, the astrophysical S-factor data, the K-electron capture data of beryllium, and the anomalous ratio of the isotope abundance of lithium in palladium-hydride (7Li/6Li) will be presented as an example for this justification. Thus, selective resonant tunneling model explains not only the 3 puzzles in Condensed Matter Nuclear Science (i.e. tunneling the Coulomb barrier, excess heat without commensurate neutron radiation, and the missing gamma radiation), but also 7 sets of hot fusion data. It predicts that there must be neutrino radiation accompanied with Condensed Matter Nuclear Phenomena in metal-hydrides. [4pt] [1] Xing Z. Li, et al., Nucl. Fusion 48 125003 (2008).

Li, Xing Zhong

2011-03-01

467

On reversion phenomena in Cu-Zr-Cr alloys  

NASA Technical Reports Server (NTRS)

Reversion phenomena in aged Cu-0.12% Zr-0.28% Cr alloy were investigated by means of resistivity measurement and transmission electron microscopy and compared with those of Cu-0.30% Zr and Cu-0.26% Cr alloys. Specimens in the form of a 0.5 mm sheet were solution-treated at 950 F for 1 hr water-quenched, aged, and finally reversed. The reversion phenomena were confirmed to exist in Cu-Zr and Cu-Zr-Cr alloys as well as Cu-Cr alloys, at aging temperatures of 300 to 500 F. The critical aging temperature for the reversion was not observed in all the alloys. Split aging increased the amount of reversion, particularly in Cu-Zr and Cu-Zr-Cr alloys, compared with that by conventional aging. The amount of reversion in Cu-Zr-Cr alloy was greatly affected by the resolution of Cr precipitate formed by preaging. Structural changes in Cu-Zr-Cr alloy due to the reversion were hardly observed by transmission electron microscopy.

Suzuki, H.; Kitano, H.; Kanno, M.

1985-01-01

468

Assessing transitional phenomena with the transitional object memory probe.  

PubMed

Winnicott's concept of transitional relatedness has captured the interest of psychoanalysts because it provides an understanding of the dialectical process occurring between inner and outer reality, and by extension, between analyst and analysand. Clinical observations related to transitional phenomena have led the authors to develop a projective early memory probe that assesses transitional phenomena. The transitional object early memory probe was tested both for its empirical validity and for its clinical utility in psychodynamic psychotherapy. Construct validity was assessed by comparing memory scores to the Rorschach Transitional Object Scale, as well as to therapist ratings of patient behaviors. Results demonstrated moderate correlations between early memory scores and Rorschach scale scores. Equally important was the finding that early memory scores were significantly correlated with therapist ratings of key behavioral patterns in therapy. A case vignette highlights the clinical application of the transitional object probe in assessing the capacity for transitional relatedness. In this case, the data gleaned from the patient's memories provided the therapist with a sharper focus on their role in the patient's growing capacity for more vital and creative contact with reality. PMID:9810109

Fowler, C; Hilsenroth, M J; Handler, L

1998-01-01

469

Compensation phenomena found in Acidithiobacillus ferrooxidans after starvation stress.  

PubMed

Acidithiobacillus ferrooxidans showed the compensate growth and oxidation after re-feeding with sufficient ferrous materials after starvation. Compensatory phenomena were first detected in chemoautotrophic organisms. Starvation stress of Acidithiobacillus ferrooxidans was achieved via culturing in low concentrations of iron. During compensation, growth and ferrous oxidation took place faster than in controls. In addition, some genes related to ferrous oxidation (such as rus) and carbon assimilation (cbbR, csoS3) were expressed in different patterns in the low energy environments. Their expression patterns can account for this increased growth and oxidation. Other groups of genes (cspAB, feoAB, fur) were suppressed in response to starvation stress. The presence of pyrite and joint cold stress can render compensation nearly undetectable. This may be why the compensation phenomena observed under these conditions was not the same as that observed under single starvation stress conditions. Gene expression reflected a possible mechanism of tolerance to starvation in Acidithiobacillus ferrooxidans, which would allow the organism to adapt and survive in ferrous-limited environments. PMID:23686751

Tu, Bowen; Li, Juan; Guo, Yueshuai; Guo, Xuejiang; Lu, Xiancai; Han, Xiaodong

2014-06-01

470

Initial aging phenomena in copper-chromium alloys  

NASA Technical Reports Server (NTRS)

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