Siu, Ho Chit
2015-01-01
We present a discrete numerical approach for forward-modeling lightcurves from stellar occultations by planetary atmospheres. Our discrete approach provides a way to arbitrarily set atmospheric properties at any radius ...
Discrete Packet Analysis for Improved Atmospheric Rejection on Modulated Laser Signals
O'Neill, M., McKenna, I., DiBenedetto, J., Capelle, G., Trainham, R.
2012-07-19
This slide-show discusses how the method of discrete packet analysis improves atmospheric compensation for quasi-CW fluorescence detection methods. This is key to improving remote sensing capabilities.
Stephens, Britton B.
Strategies for measurement of atmospheric column means of carbon dioxide from aircraft using and Structure: Instruments and techniques; KEYWORDS: carbon dioxide, column mean, column integral, COBRA, flask, Strategies for measurement of atmospheric column means of carbon dioxide from aircraft using discrete
HYPERsensarium : an archive of atmospheric conditions
Shaw, Kelly E. (Kelly Evelyn)
2013-01-01
HYPERsensarium proposes a tangible interface of atmospheres for public experience through an archive of historical and projected weathers. While architecture's purpose has long been to act as the technical boundary between ...
, as giant planets should be warmest, largest, and brightest when they are young, but will cool, contractSYNTHETIC SPECTRA AND COLORS OF YOUNG GIANT PLANET ATMOSPHERES: EFFECTS OF INITIAL CONDITIONS 2008 March 17; accepted 2008 May 7 ABSTRACT We examine the spectra and infrared colors of the cool
Discrete Elements Method: A New Kind of Initial Conditions - Tetrahedral Packing of Balls
Mark A. Tsayger
2014-12-15
The Paper discusses the use of the regular packing of identical balls with the coordination number 4 as a model of a medium consisting of fluid and solid particles in the conditions of fluidization. It is proposed to use the examined packing of balls as an initial condition for the calculations by the Discrete Elements Method (DEM) in technological processes in the fluidized bed in industry, as well as in the modeling of processes that occur in hydraulic and pneumatic transport of granular materials. Filtration properties of such packing required for its use as an initial condition in calculations by DEM are estimated.
Discrete Elements Method: A New Kind of Initial Conditions - Tetrahedral Packing of Balls
Mark A. Tsayger
2015-10-13
The Paper discusses the use of the regular packing of identical balls with the coordination number 4 as a model of a medium consisting of fluid and solid particles in the conditions of fluidization. It is proposed to use the examined packing of balls as an initial condition for the calculations by the Discrete Elements Method (DEM) in technological processes in the fluidized bed in industry, as well as in the modeling of processes that occur in hydraulic and pneumatic transport of granular materials. Filtration properties of such packing required for its use as an initial condition in calculations by DEM are estimated.
Standard 1D solar atmosphere as initial condition for MHD simulations and switch-on effects
Bourdin, Philippe-A
2015-01-01
Many applications in Solar physics need a 1D atmospheric model as initial condition or as reference for inversions of observational data. The VAL atmospheric models are based on observations and are widely used since decades. Complementary to that, the FAL models implement radiative hydrodynamics and showed the shortcomings of the VAL models since almost equally long time. In this work, we present a new 1D layered atmosphere that spans not only from the photosphere to the transition region, but from the solar interior up to far in the corona. We also discuss typical mistakes that are done when switching on simulations based on such an initial condition and show how the initial condition can be equilibrated so that a simulation can start smoothly. The 1D atmosphere we present here served well as initial condition for HD and MHD simulations and should also be considered as reference data for solving inverse problems.
Miller, William H.
of a bimo- lecular chemical reaction, i.e., state-to-state differential and integral cross sections. HoweverCalculation of the cumulative reaction probability via a discrete variable representation is suggested for the calculation of the microcanonical cumulative reaction probability uia flux autocorrelation
Hively, Lee M.
2014-09-16
Data collected from devices and human condition may be used to forewarn of critical events such as machine/structural failure or events from brain/heart wave data stroke. By monitoring the data, and determining what values are indicative of a failure forewarning, one can provide adequate notice of the impending failure in order to take preventive measures. This disclosure teaches a computer-based method to convert dynamical numeric data representing physical objects (unstructured data) into discrete-phase-space states, and hence into a graph (structured data) for extraction of condition change.
Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E.J.; Albuquerque, I.F.M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; /Mexico U., ICN /Santiago de Compostela U.
2012-01-01
Atmospheric conditions at the site of a cosmic ray observatory must be known for reconstructing observed extensive air showers. The Global Data Assimilation System (GDAS) is a global atmospheric model predicated on meteorological measurements and numerical weather predictions. GDAS provides altitude-dependent profiles of the main state variables of the atmosphere like temperature, pressure, and humidity. The original data and their application to the air shower reconstruction of the Pierre Auger Observatory are described. By comparisons with radiosonde and weather station measurements obtained on-site in Malargue and averaged monthly models, the utility of the GDAS data is shown.
OH-initiated oxidation of benzene Part I. Phenol formation under atmospheric conditions
OH-initiated oxidation of benzene Part I. Phenol formation under atmospheric conditions Rainer-radical initiated oxidation of benzene was studied in two simulation chambers: (1) the large-volume outdoor chamber-red spectroscopy (FTIR) were used to simultaneously measure phenol and benzene. The second study used only FTIR
Sulfur capture by oil shale ashes under atmospheric and pressurized FBC conditions
Yrjas, K.P.; Hupa, M. [Aabo Akademi Univ., Turku (Finland). Dept. of Chemical Engineering; Kuelaots, I.; Ots, A. [Tallinn Technical Univ. (Estonia). Thermal Engineering Dept.
1995-12-31
When oil shale contains large quantities of limestone, a significant auto-absorption of sulfur is possible under suitable conditions. The sulfur capture by oil shale ashes has been studied using a pressurized thermogravimetric apparatus. The chosen experimental conditions were typical for atmospheric and pressurized fluidized bed combustion. The Ca/S molar ratios in the two oil shales studied were 8 (Estonian) and 10 (Israeli). The samples were first burned in a gas atmosphere containing O{sub 2} and N{sub 2} (and CO{sub 2} if pressurized). After the combustion step, SO{sub 2} was added and sulfation started. The results with the oil shales were compared to those obtained with an oil shale cyclone ash from the Narva power plant in Estonia. In general, the results from the sulfur capture experiments under both atmospheric and pressurized conditions showed that the oil shale cannot only capture its own sulfur but also significant amounts of additional sulfur of another fuel if the fuels are mixed together. For example from the runs at atmospheric pressure, the conversion of CaO to CaSO{sub 4} was about 70% for Israeli oil shale and about 55% for Estonian oil shale (850 C). For the cyclone ash the corresponding conversion was about 20%. In comparison it could be mentioned that under the same conditions the conversions of natural limestones are about 30%. The reason the cyclone ash was a poor sulfur absorbent was probably due to its temperature history. In Narva the oil shale was burned at a significantly higher temperature (1,400 C) than was used in the experiments (750 C and 850 C). This caused the ash to sinter and the reactive surface area of the cyclone ash was therefore decreased.
Hahn, J; Bernlöhr, K; Krüger, P; Lo, Y T E; Chadwick, P M; Daniel, M K; Deil, C; Gast, H; Kosack, K; Marandon, V
2015-01-01
Cherenkov telescope experiments, such as H.E.S.S., have been very successful in astronomical observations in the very-high-energy (VHE; E $>$ 100 GeV) regime. As an integral part of the detector, such experiments use Earth's atmosphere as a calorimeter. For the calibration and energy determination, a standard model atmosphere is assumed. Deviations of the real atmosphere from the model may therefore lead to an energy misreconstruction of primary gamma rays. To guarantee satisfactory data quality with respect to difficult atmospheric conditions, several atmospheric data quality criteria are implemented in the H.E.S.S. software. These quantities are sensitive to clouds and aerosols. Here, the Cherenkov transparency coefficient will be presented. It is a new monitoring quantity that is able to measure long-term changes in the atmospheric transparency. The Cherenkov transparency coefficient derives exclusively from Cherenkov data and is quite hardware-independent. Furthermore, its positive correlation with indepe...
Clegg, Sanuel M; Barefield, James E; Humphries, Seth D; Wiens, Roger C; Vaniman, D. T.; Sharma, S. K.; Misra, A. K.; Dyar, M. D.; Smrekar, S. E.
2010-12-13
The extreme Venus surface temperatures ({approx}740 K) and atmospheric pressures ({approx}93 atm) create a challenging environment for surface missions. Scientific investigations capable of Venus geochemical observations must be completed within hours of landing before the lander will be overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing the geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. and Sharma et al. demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with Raman - LIBS and demonstrate quantitative analysis under Venus surface conditions. Raman and LIBS are highly complementary analytical techniques capable of detecting both the mineralogical and geochemical composition of Venus surface materials. These techniques have the potential to profoundly increase our knowledge of the Venus surface composition, which is currently limited to geochemical data from Soviet Venera and VEGA landers that collectively suggest a surface composition that is primarily tholeiitic basaltic with some potentially more evolved compositions and, in some locations, K-rich trachyandesite. These landers were not equipped to probe the surface mineralogy as can be accomplished with Raman spectroscopy. Based on the observed compositional differences and recognizing the imprecise nature of the existing data, 15 samples were chosen to constitute a Venus-analog suite for this study, including five basalts, two each of andesites, dacites, and sulfates, and single samples of a foidite, trachyandesite, rhyolite, and basaltic trachyandesite under Venus conditions. LIBS data reduction involved generating a partial least squares (PLS) model with a subset of the rock powder standards to quantitatively determine the major elemental abundance of the remaining samples. PLS analysis suggests that the major element compositions can be determined with root mean square errors ca. 5% (absolute) for SiO{sub 2}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}(total), MgO, and CaO, and ca. 2% or less for TiO{sub 2}, Cr{sub 2}O{sub 3}, MnO, K{sub 2}O, and Na{sub 2}O. Finally, the Raman experiments have been conducted under supercritical CO{sub 2} involving single-mineral and mixed-mineral samples containing talc, olivine, pyroxenes, feldspars, anhydrite, barite, and siderite. The Raman data have shown that the individual minerals can easily be identified individually or in mixtures.
Harilal, S. S.
Comparison of optical emission from nanosecond and femtosecond laser produced plasma in atmosphere November 2012 Accepted 12 May 2013 Available online 18 May 2013 Keywords: Optical emission spectroscopy In this study we examine the emission from brass plasma produced by ns and fs laser ablation under both vacuum
Tatarova, E.; Henriques, J.; Dias, A.; Ferreira, C. M.; Luhrs, C. C.; Phillips, J.; Abrashev, M. V.
2013-09-23
Microwave atmospheric pressure plasmas driven by surface waves were used to synthesize graphene sheets from vaporized ethanol molecules carried through argon plasma. In the plasma, ethanol decomposes creating carbon atoms that form nanostructures in the outlet plasma stream, where external cooling/heating was applied. It was found that the outlet gas stream temperature plays an important role in the nucleation processes and the structural quality of the produced nanostructures. The synthesis of few layers (from one to five) graphene has been confirmed by high-resolution transmission electron microscopy. Raman spectral studies were conducted to determine the ratio of the 2D to G peaks (>2). Disorder D-peak to G-peak intensity ratio decreases when outlet gas stream temperature decreases.
Smith, C.; Brigmon, R.
2009-10-20
Legionnaires disease is a pneumonia caused by the inhalation of the bacterium Legionella pneumophila. The majority of illnesses have been associated with cooling towers since these devices can harbor and disseminate the bacterium in the aerosolized mist generated by these systems. Historically, Savannah River Site (SRS) cooling towers have had occurrences of elevated levels of Legionella in all seasons of the year and in patterns that are difficult to predict. Since elevated Legionella in cooling tower water are a potential health concern a question has been raised as to the best control methodology. In this work we analyze available chemical, biological, and atmospheric data to determine the best method or key parameter for control. The SRS 4Q Industrial Hygiene Manual, 4Q-1203, 1 - G Cooling Tower Operation and the SRNL Legionella Sampling Program, states that 'Participation in the SRNL Legionella Sampling Program is MANDATORY for all operating cooling towers'. The resulting reports include L. pneumophila concentration information in cells/L. L. pneumophila concentrations >10{sup 7} cells/L are considered elevated and unsafe so action must be taken to reduce these densities. These remedial actions typically include increase biocide addition or 'shocking'. Sometimes additional actions are required if the problem persists including increase tower maintenance (e.g. cleaning). Evaluation of 14 SRS cooling towers, seven water quality parameters, and five Legionella serogroups over a three-plus year time frame demonstrated that cooling tower water Legionella densities varied widely though out this time period. In fact there was no one common consistent significant variable across all towers. The significant factors that did show up most frequently were related to suspended particulates, conductivity, pH, and dissolved oxygen, not chlorine or bromine as might be expected. Analyses of atmospheric data showed that there were more frequent significant elevated Legionella concentrations when the dew point temperature was high--a summertime occurrence. However, analysis of the three years of Legionella monitoring data of the 14 different SRS Cooling Towers demonstrated that elevated concentrations are observed at all temperatures and seasons. The objective of this study is to evaluate the ecology of L. pneumophila including serogroups and population densities, chemical, and atmospheric data, on cooling towers at SRS to determine whether relationships exist among water chemistry, and atmospheric conditions. The goal is to more fully understand the conditions which inhibit or encourage L. pneumophila growth and supply this data and associated recommendations to SRS Cooling Tower personnel for improved management of operation. Hopefully this information could then be used to help control L. pneumophila growth more effectively in SRS cooling tower water.
CHARACTERIZATION OF CLOUDS IN TITAN'S TROPICAL ATMOSPHERE
Griffith, Caitlin A.; Penteado, Paulo; Rodriguez, Sebastien; Baines, Kevin H.; Buratti, Bonnie; Sotin, Christophe; Clark, Roger; Nicholson, Phil; Jaumann, Ralf
2009-09-10
Images of Titan's clouds, possible over the past 10 years, indicate primarily discrete convective methane clouds near the south and north poles and an immense stratiform cloud, likely composed of ethane, around the north pole. Here we present spectral images from Cassini's Visual Mapping Infrared Spectrometer that reveal the increasing presence of clouds in Titan's tropical atmosphere. Radiative transfer analyses indicate similarities between summer polar and tropical methane clouds. Like their southern counterparts, tropical clouds consist of particles exceeding 5 {mu}m. They display discrete structures suggestive of convective cumuli. They prevail at a specific latitude band between 8 deg. - 20 deg. S, indicative of a circulation origin and the beginning of a circulation turnover. Yet, unlike the high latitude clouds that often reach 45 km altitude, these discrete tropical clouds, so far, remain capped to altitudes below 26 km. Such low convective clouds are consistent with the highly stable atmospheric conditions measured at the Huygens landing site. Their characteristics suggest that Titan's tropical atmosphere has a dry climate unlike the south polar atmosphere, and despite the numerous washes that carve the tropical landscape.
Glen, Crystal
2012-02-14
of the processes leading to SOA production under ambient gaseous and particulate concentrations as well as the impact these aerosol types have on climate is poorly understood. Although the majority of atmospheric aerosols scatter radiation either directly...
Brandeis, Genevičve
for the condensation of a water ocean T. Lebrun1 , H. Massol1 , E. Chassefičre1 , A. Davaille2 , E. Marcq3 , P. Sarda1-planet distance. Our results suggest that a steam atmosphere delays the end of the magma ocean phase by typically 1 Myr. Water vapor condenses to an ocean after 0.1 Myr, 1.5 Myr and 10 Myr for, respectively, Mars
Churchfield, M. J.; Michalakes, J.; Vanderwende, B.; Lee, S.; Sprague, M. A.; Lundquist, J. K.; Moriarty, P. J.
2013-10-01
Wind plant aerodynamics are directly affected by the microscale weather, which is directly influenced by the mesoscale weather. Microscale weather refers to processes that occur within the atmospheric boundary layer with the largest scales being a few hundred meters to a few kilometers depending on the atmospheric stability of the boundary layer. Mesoscale weather refers to large weather patterns, such as weather fronts, with the largest scales being hundreds of kilometers wide. Sometimes microscale simulations that capture mesoscale-driven variations (changes in wind speed and direction over time or across the spatial extent of a wind plant) are important in wind plant analysis. In this paper, we present our preliminary work in coupling a mesoscale weather model with a microscale atmospheric large-eddy simulation model. The coupling is one-way beginning with the weather model and ending with a computational fluid dynamics solver using the weather model in coarse large-eddy simulation mode as an intermediary. We simulate one hour of daytime moderately convective microscale development driven by the mesoscale data, which are applied as initial and boundary conditions to the microscale domain, at a site in Iowa. We analyze the time and distance necessary for the smallest resolvable microscales to develop.
Li, Lee Liu, Lun; Liu, Yun-Long; Bin, Yu; Ge, Ya-Feng; Lin, Fo-Chang
2014-01-14
Atmospheric air diffuse plasmas have enormous application potential in various fields of science and technology. Without dielectric barrier, generating large-scale air diffuse plasmas is always a challenging issue. This paper discusses and analyses the formation mechanism of cold homogenous plasma. It is proposed that generating stable diffuse atmospheric plasmas in open air should meet the three conditions: high transient power with low average power, excitation in low average E-field with locally high E-field region, and multiple overlapping electron avalanches. Accordingly, an experimental configuration of generating large-scale barrier-free diffuse air plasmas is designed. Based on runaway electron theory, a low duty-ratio, high voltage repetitive nanosecond pulse generator is chosen as a discharge excitation source. Using the wire-electrodes with small curvature radius, the gaps with highly non-uniform E-field are structured. Experimental results show that the volume-scaleable, barrier-free, homogeneous air non-thermal plasmas have been obtained between the gap spacing with the copper-wire electrodes. The area of air cold plasmas has been up to hundreds of square centimeters. The proposed formation conditions of large-scale barrier-free diffuse air plasmas are proved to be reasonable and feasible.
Probabilistic Calibration of a Discrete Particle Model
Zhang, Yanbei
2011-10-21
A discrete element model (DEM) capable of reproducing the mechanistic behavior of a triaxial compressive test performed on a Vosges sandstone specimen is presented considering similar experimental testing conditions and ...
R. L. Oldershaw
2007-12-19
The possibility that global discrete dilation invariance is a fundamental symmetry principle of nature is explored. If the discrete self-similarity observed in nature is exact, then the Principle of General Covariance needs to be broadened in order to accommodate this form of discrete conformal invariance, and a further generalization of relativity theory is required.
Farfan, E.; Jannik, T.
2011-10-01
When assessing the feasibility of remediation following the detonation of a radiological dispersion device or improvised nuclear device in a large city, several issues should be considered including the levels and characteristics of the radioactive contamination, the availability of resources required for decontamination, and the planned future use of the city's structures and buildings. Currently, little is known about radionuclide penetration into construction materials in an urban environment. Knowledge in this area would be useful when considering costs of a thorough decontamination of buildings, artificial structures, and roads in an affected urban environment. Pripyat, a city substantially contaminated by the Chernobyl Nuclear Power Plant accident in April 1986, may provide some answers. The main objective of this study was to assess the depth of {sup 90}Sr and {sup 137}Cs penetration into reinforced concrete structures in a highly contaminated urban environment under natural weather conditions. Thirteen reinforced concrete core samples were obtained from external surfaces of a contaminated building in Pripyat. The concrete cores were drilled to obtain sample layers of 0-5, 5-10, 10-15, 15-20, 20-30, 30-40, and 40-50 mm. Both {sup 90}Sr and {sup 137}Cs were detected in the entire 0-50 mm profile of the reinforced cores sampled. In most of the cores, over 90% of the total {sup 137}Cs inventory and 70% of the total {sup 90}Sr inventory was found in the first 0-5 mm layer of the reinforced concrete. {sup 90}Sr had penetrated markedly deeper into the reinforced concrete structures than {sup 137}Cs.
Prathap, C.; Ray, Anjan; Ravi, M.R. [Department of Mechanical Engineering, Indian Institute of Technology, Delhi, New Delhi 110016 (India)
2008-10-15
The objective of this investigation was to study the effect of dilution with nitrogen on the laminar burning velocity and flame stability of syngas fuel (50% H{sub 2}-50% CO by volume)-air (21% O{sub 2}-79% N{sub 2} by volume) mixtures. The syngas fuel composition considered in this work comprised x% N{sub 2} by volume and (100-x)% an equimolar mixture of CO and H{sub 2}. The proportion x (i.e., %N{sub 2}) was varied from 0 to 60% while the H{sub 2}/CO ratio was always kept as unity. Spherically expanding flames were generated by centrally igniting homogeneous fuel-air gas mixtures in a 40-L cylindrical combustion chamber fitted with optical windows. Shadowgraphy technique with a high-speed imaging camera was used to record the propagating spherical flames. Unstretched burning velocity was calculated following the Karlovitz theory for weakly stretched flames. Also, Markstein length was calculated to investigate the flame stability conditions for the fuel-air mixtures under consideration. Experiments were conducted for syngas fuel with different nitrogen proportions (0-60%) at 0.1 MPa (absolute), 302{+-}3K, and equivalence ratios ranging from 0.6 to 3.5. All the measurements were compared with the numerical predictions obtained using RUN-1DL and PREMIX with a contemporary chemical kinetic scheme. Dilution with nitrogen in different proportions in syngas resulted in (a) decrease in laminar burning velocity due to reduction in heat release and increase in heat capacity of unburned gas mixture and hence the flame temperature, (b) shift in occurrence of peak laminar burning velocity from {phi}=2.0 for 0% N{sub 2} dilution to {phi}=1.4 for 60% N{sub 2} dilution, (c) augmentation of the coupled effect of flame stretch and preferential diffusion on laminar burning velocity, and (d) shift in the equivalence ratio for transition from stable to unstable flames from {phi}=0.6 for 0% N{sub 2} dilution to {phi}=1.0 for 60% N{sub 2} dilution. The present work also indicated that if the fuel mole fraction in the wide range of fuel-air mixtures investigated is less than 22%, then those fuel mixtures are in the unstable regime with regard to preferential diffusion. (author)
Discrete Fracture Reservoir Simulation
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Discrete Fracture Reservoir Simulation Shale Gas Flow Simulation Shale Gas Flow Simulation FRACGENNFFLOW, fractured reservoir modeling software developed by NETL's Geological and...
Daniels, Megan Hanako
2010-01-01
groundwater, land-surface, and mesoscale atmospheric model-and modification of mesoscale circulations. , Mon. Wea.J. Davis, The effects of mesoscale surface heterogeneity on
Morris, J; Johnson, S
2007-12-03
The Distinct Element Method (also frequently referred to as the Discrete Element Method) (DEM) is a Lagrangian numerical technique where the computational domain consists of discrete solid elements which interact via compliant contacts. This can be contrasted with Finite Element Methods where the computational domain is assumed to represent a continuum (although many modern implementations of the FEM can accommodate some Distinct Element capabilities). Often the terms Discrete Element Method and Distinct Element Method are used interchangeably in the literature, although Cundall and Hart (1992) suggested that Discrete Element Methods should be a more inclusive term covering Distinct Element Methods, Displacement Discontinuity Analysis and Modal Methods. In this work, DEM specifically refers to the Distinct Element Method, where the discrete elements interact via compliant contacts, in contrast with Displacement Discontinuity Analysis where the contacts are rigid and all compliance is taken up by the adjacent intact material.
Raman, Sethu
that the influence of the urban region on wind patterns and atmospheric stability could be studied. HeightAtmospheric Environment ] (
Atmospheric optical calibration system
Hulstrom, Roland L. (Bloomfield, CO); Cannon, Theodore W. (Golden, CO)
1988-01-01
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.
Atmospheric optical calibration system
Hulstrom, R.L.; Cannon, T.W.
1988-10-25
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.
Discrete Fourier Transform Javier Montoya
Giger, Christine
Discrete Fourier Transform Javier Montoya Photogrammetry and Remote Sensing ETH Zurich March 16, 2012 1 Introduction The Discrete form of the Fourier transform is known as Discrete Fourier Transform domain using the Inverse Discrete Fourier Transform (IDFT): f(x) = 1 N N-1 x=0 F(u)ej 2 N ux for u = 0, 1
A discrete fractional random transform
Zhengjun Liu; Haifa Zhao; Shutian Liu
2006-05-20
We propose a discrete fractional random transform based on a generalization of the discrete fractional Fourier transform with an intrinsic randomness. Such discrete fractional random transform inheres excellent mathematical properties of the fractional Fourier transform along with some fantastic features of its own. As a primary application, the discrete fractional random transform has been used for image encryption and decryption.
Constraint analysis for variational discrete systems
Dittrich, Bianca; Höhn, Philipp A.; Institute for Theoretical Physics, Universiteit Utrecht, Leuvenlaan 4, NL-3584 CE Utrecht
2013-09-15
A canonical formalism and constraint analysis for discrete systems subject to a variational action principle are devised. The formalism is equivalent to the covariant formulation, encompasses global and local discrete time evolution moves and naturally incorporates both constant and evolving phase spaces, the latter of which is necessary for a time varying discretization. The different roles of constraints in the discrete and the conditions under which they are first or second class and/or symmetry generators are clarified. The (non-) preservation of constraints and the symplectic structure is discussed; on evolving phase spaces the number of constraints at a fixed time step depends on the initial and final time step of evolution. Moreover, the definition of observables and a reduced phase space is provided; again, on evolving phase spaces the notion of an observable as a propagating degree of freedom requires specification of an initial and final step and crucially depends on this choice, in contrast to the continuum. However, upon restriction to translation invariant systems, one regains the usual time step independence of canonical concepts. This analysis applies, e.g., to discrete mechanics, lattice field theory, quantum gravity models, and numerical analysis.
Discrete multivariate distributions
Oleg Yu. Vorobyev; Lavrentiy S. Golovkov
2011-02-22
This article brings in two new discrete distributions: multidimensional Binomial distribution and multidimensional Poisson distribution. Those distributions were created in eventology as more correct generalizations of Binomial and Poisson distributions. Accordingly to eventology new laws take into account full distribution of events. Also, in article its characteristics and properties are described
Jaquin, R.F.
1989-01-01
Profiles of scattered light above the planetary limb from 116 Viking Orbiter images are used to constrain the temporal and spatial behavior of aerosols suspended in the Martian atmosphere. The data cover a wide range of seasons, locations, and viewing geometry, providing information about the aerosol optical properties and vertical distribution. The typical atmospheric column contains one or more discrete, optically thin, ice-like haze layers between 30 and 90 km elevation whose composition is inferred to be water ice. Below the detached hazes, a continuous haze, interpreted to have a large dust component, extends from as much as 50 km to the surface. The haze distribution exhibits an annual variation that reflects a seasonally driven circulation in the middle atmosphere. The potential role of stationary gravity waves in modifying the middle atmosphere circulation is explored using a linear theory applied to a realistic Martian environment. Martian topography derived from radar observations is decomposed into Fourier harmonics and used to linearly superpose gravity waves arising from each component. The larger amplitude topography on Mars combined with the absence of extended regions of smooth topography like oceans generates larger wave amplitudes than on the Earth. The circulation of the middle atmosphere is examined using a two-dimensional, linearized, axisymmetric model successfully employed in the study of the terrestrial mesosphere. Illustrations of temperature and wind speeds are presented for the southern summer solstice and southern spring equinox.
L. R. G. Fontes; C. M. Newman; K. Ravishankar; E. Schertzer
2007-04-20
The dynamical discrete web (DDW), introduced in recent work of Howitt and Warren, is a system of coalescing simple symmetric one-dimensional random walks which evolve in an extra continuous dynamical parameter s. The evolution is by independent updating of the underlying Bernoulli variables indexed by discrete space-time that define the discrete web at any fixed s. In this paper, we study the existence of exceptional (random) values of s where the paths of the web do not behave like usual random walks and the Hausdorff dimension of the set of such exceptional s. Our results are motivated by those about exceptional times for dynamical percolation in high dimension by H\\"aggstrom, Peres and Steif, and in dimension two by Schramm and Steif. The exceptional behavior of the walks in DDW is rather different from the situation for dynamical random walks of Benjamini, H\\"aggstrom, Peres and Steif. In particular, we prove that there are exceptional values of s for which the walk from the origin S^s(n) has limsup S^s(n)/\\sqrt n \\leq K with a nontrivial dependence of the Hausdorff dimension on K. We also discuss how these and other results extend to the dynamical Brownian web, a natural scaling limit of DDW. The scaling limit is the focus of a paper in preparation; it was studied by Howitt and Warren and is related to the Brownian net of Sun and Swart.
Discrete Fracture Reservoir Simulation
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalentLaboratory | National NuclearDiscoveringDiscrete Fracture Reservoir
Hirsch, M.; Morisi, S.; Peinado, E.; Valle, J. W. F. [AHEP Group, Institut de Fisica Corpuscular--C.S.I.C./Universitat de Valencia, Edificio Institutos de Paterna, Apartado 22085, E-46071 Valencia (Spain)
2010-12-01
We propose a new motivation for the stability of dark matter (DM). We suggest that the same non-Abelian discrete flavor symmetry which accounts for the observed pattern of neutrino oscillations, spontaneously breaks to a Z{sub 2} subgroup which renders DM stable. The simplest scheme leads to a scalar doublet DM potentially detectable in nuclear recoil experiments, inverse neutrino mass hierarchy, hence a neutrinoless double beta decay rate accessible to upcoming searches, while {theta}{sub 13}=0 gives no CP violation in neutrino oscillations.
Discrete Probability Distributions
Stewart, William J.
, 2, . . . , n, the moments of the discrete uniform distribution are given by E[Xk ] = nX i=1 ik /n. In particular, E[X] = nX i=1 i/n = 1 n nX i=1 i = 1 n n(n + 1) 2 = n + 1 2 , and, using the well-known formula for the sum of the squares of the first n integers, E[X2 ] = nX i=1 i2 /n = 1 n nX i=1 i2 = 1 n n(n + 1)(2n
Thermodynamics of discrete quantum processes
Janet Anders; Vittorio Giovannetti
2012-11-01
We define thermodynamic configurations and identify two primitives of discrete quantum processes between configurations for which heat and work can be defined in a natural way. This allows us to uncover a general second law for any discrete trajectory that consists of a sequence of these primitives, linking both equilibrium and non-equilibrium configurations. Moreover, in the limit of a discrete trajectory that passes through an infinite number of configurations, i.e. in the reversible limit, we recover the saturation of the second law. Finally, we show that for a discrete Carnot cycle operating between four configurations one recovers Carnot's thermal efficiency.
Thomas K. Gaisser
2006-12-11
This paper is a brief overview of the theory and experimental data of atmospheric neutrino production at the fiftieth anniversary of the experimental discovery of neutrinos.
Constucting Discrete KSurfaces Ivan Sterling
Sterling, Ivan
Constucting Discrete KSurfaces Ivan Sterling (joint work with Tim Ho#mann, and Ulrich Pinkall) Old it is possible to find other examples (FIGURE 4). 2 #12; Figure 4. Ho#manSterling Discrete KSurface 4. Computer and examples can be found at www.jreality.de. References [1] G.T. Bennett, A new mechanism, Engineering 76
Note on Discrete Gauge Anomalies
T. Banks; M. Dine
1991-10-02
We consider the probem of gauging discrete symmetries. All valid constraints on such symmetries can be understood in the low energy theory in terms of instantons. We note that string perturbation theory often exhibits global discrete symmetries, which are broken non-perturbatively.
Discrete generalized multigroup theory and applications
Zhu, Lei, Ph. D. Massachusetts Institute of Technology
2012-01-01
This study develops a fundamentally new discrete generalized multigroup energy expansion theory for the linear Boltzmann transport equation. Discrete orthogonal polynomials are used, in conjunction with the traditional ...
Environmental Conditions Environmental Conditions
Environmental Conditions Environmental Conditions Appendix II The unique geology, hydrology and instream habitat. This chapter examines how environmental conditions in the Deschutes watershed affect, the discussion characterizes the environmental conditions within three watershed areas: the Lower Deschutes
Common Discrete Distributions Statistics 104
Irwin, Mark E.
must be all 1, so it is omitted. Discrete Distributions 4 #12;H HHH HHH HH k p 0.01 0.05 0.10 0.20 0
Discrete geodesics and cellular automata
Pablo Arrighi; Gilles Dowek
2015-07-24
This paper proposes a dynamical notion of discrete geodesics, understood as straightest trajectories in discretized curved spacetime. The notion is generic, as it is formulated in terms of a general deviation function, but readily specializes to metric spaces such as discretized pseudo-riemannian manifolds. It is effective: an algorithm for computing these geodesics naturally follows, which allows numerical validation---as shown by computing the perihelion shift of a Mercury-like planet. It is consistent, in the continuum limit, with the standard notion of timelike geodesics in a pseudo-riemannian manifold. Whether the algorithm fits within the framework of cellular automata is discussed at length. KEYWORDS: Discrete connection, parallel transport, general relativity, Regge calculus.
Discrete geodesics and cellular automata
Arrighi, Pablo
2015-01-01
This paper proposes a dynamical notion of discrete geodesics, understood as straightest trajectories in discretized curved spacetime. The notion is generic, as it is formulated in terms of a general deviation function, but readily specializes to metric spaces such as discretized pseudo-riemannian manifolds. It is effective: an algorithm for computing these geodesics naturally follows, which allows numerical validation---as shown by computing the perihelion shift of a Mercury-like planet. It is consistent, in the continuum limit, with the standard notion of timelike geodesics in a pseudo-riemannian manifold. Whether the algorithm fits within the framework of cellular automata is discussed at length. KEYWORDS: Discrete connection, parallel transport, general relativity, Regge calculus.
Tensile damage response from discrete element virtual testing
Paris-Sud XI, Université de
Tensile damage response from discrete element virtual testing A. DELAPLACE LMT-Cachan, ENS Cachan conditions on brittle materials, damage can generally not be re- duced to a simple scalar. Microcrack into account the damage anisotropy in phenomenological models is a possible option, but the identification
Discrete Hamiltonian for General Relativity
Ziprick, Jonathan
2015-01-01
Beginning from canonical general relativity written in terms of Ashtekar variables, we derive a discrete phase space with a physical Hamiltonian for gravity. The key idea is to define the gravitational fields within a complex of three-dimensional cells such that the dynamics is completely described by discrete boundary variables, and the full theory is recovered in the continuum limit. Canonical quantization is attainable within the loop quantum gravity framework, and we believe this will lead to a promising candidate for quantum gravity.
Discrete Hamiltonian for General Relativity
Jonathan Ziprick; Jack Gegenberg
2015-07-27
Beginning from canonical general relativity written in terms of Ashtekar variables, we derive a discrete phase space with a physical Hamiltonian for gravity. The key idea is to define the gravitational fields within a complex of three-dimensional cells such that the dynamics is completely described by discrete boundary variables, and the full theory is recovered in the continuum limit. Canonical quantization is attainable within the loop quantum gravity framework, and we believe this will lead to a promising candidate for quantum gravity.
Quantum chaos on discrete graphs
Uzy Smilansky
2007-04-26
Adapting a method developed for the study of quantum chaos on {\\it quantum (metric)} graphs \\cite {KS}, spectral $\\zeta$ functions and trace formulae for {\\it discrete} Laplacians on graphs are derived. This is achieved by expressing the spectral secular equation in terms of the periodic orbits of the graph, and obtaining functions which belongs to the class of $\\zeta$ functions proposed originally by Ihara \\cite {Ihara}, and expanded by subsequent authors \\cite {Stark,Sunada}. Finally, a model of "classical dynamics" on the discrete graph is proposed. It is analogous to the corresponding classical dynamics derived for quantum graphs \\cite {KS}.
ENVIRONMENTAL CONDITIONS INFLUENCE ON EMBEDDED CAPACITORS -COMPARISON WITH DISCRETE CAPACITORS
Boyer, Edmond
. Polymer-ceramic composites are expected to be the major candidate as dielectric interlayer for embedded of early failures peculiar to ceramic capacitors, technologists are using new polymer-ceramic materials is caused by the mismatch of the thermal expansion coefficient and the thermal conductivity between
Gunzburger, Max
2013-03-12
The work reported is in pursuit of these goals: high-quality unstructured, non-uniform Voronoi and Delaunay grids; improved finite element and finite volume discretization schemes; and improved finite element and finite volume discretization schemes. These are sought for application to spherical and three-dimensional applications suitable for ocean, atmosphere, ice-sheet, and other climate modeling applications.
Evaluation of three spatial discretization schemes with the Galewsky et al. test
Reich, Sebastian
potential enstrophy. Potential vorticity (PV) is one of the quantities of main interest in atmospheric flows and maintain PV as well as other con- servation properties in a long-term simulation. The discretized vorticity. His idea is adopted by Sommer & N´evir (2009) for the shallow-equations on a staggered geodesic
Discrete and Hybrid Nonholonomy Antonio Bicchi1
Piccoli, Benedetto
Discrete and Hybrid Nonholonomy Antonio Bicchi1 , Alessia Marigo2 , and Benedetto Piccoli3 1 Centro such as cars, trucks with trailers, rolling 3D objects, underactuated mechanisms, satellites, etc., has made of systems, allowing for discrete and hybrid (mixed continuous and discrete) configurations and transi- tions
On the discretization of the Euler-Poincaré-Suslov equations in $SO(3)$
Fernando Jimenez; Juergen Scheurle
2015-06-03
In this paper we explore the discretization of Euler-Poincar\\'e-Suslov equations in $SO(3)$. We prove that the consistency order of the unreduced and reduced setups, when the discrete reconstruction equation is given by a Cayley retraction map, are related to each other in a nontrivial way. Moreover, we give precise conditions under which general and variational integrators generate a discrete flow preserving the distribution. These results are carefully illustrated by the example of the Suslov problem in $SO(3)$, establishing general consistency bounds and illustrating the performance of several discretizations through some plots. Finally, we show that any constraints-preserving discretization may be understood as being generated by the exact evolution map of a time-periodic non-autonomous perturbation of the original continuous-time nonholonomic system.
Yoon, Joon Sik, 1973-
2005-01-01
An understanding of how discrete particles in the micron to submicron range behave in porous media is important to a number of environmental problems. Discrete particle behavior in the interior of a porous medium is complex ...
Invariant discretization schemes for the shallow-water equations
Alexander Bihlo; Roman O. Popovych
2013-01-03
Invariant discretization schemes are derived for the one- and two-dimensional shallow-water equations with periodic boundary conditions. While originally designed for constructing invariant finite difference schemes, we extend the usage of difference invariants to allow constructing of invariant finite volume methods as well. It is found that the classical invariant schemes converge to the Lagrangian formulation of the shallow-water equations. These schemes require to redistribute the grid points according to the physical fluid velocity, i.e., the mesh cannot remain fixed in the course of the numerical integration. Invariant Eulerian discretization schemes are proposed for the shallow-water equations in computational coordinates. Instead of using the fluid velocity as the grid velocity, an invariant moving mesh generator is invoked in order to determine the location of the grid points at the subsequent time level. The numerical conservation of energy, mass and momentum is evaluated for both the invariant and non-invariant schemes.
Fast Computation Algorithm for Discrete Resonances among Gravity Waves
Elena Kartashova
2006-05-25
Traditionally resonant interactions among short waves, with large real wave-numbers, were described statistically and only a small domain in spectral space with integer wave-numbers, discrete resonances, had to be studied separately in resonators. Numerical simulations of the last few years showed unambiguously the existence of some discrete effects in the short-waves part of the wave spectrum. Newly presented model of laminated turbulence explains theoretically appearance of these effects thus putting a novel problem - construction of fast algorithms for computation of solutions of resonance conditions with integer wave-numbers of order $10^3$ and more. Example of such an algorithm for 4-waves interactions of gravity waves is given. Its generalization on the different types of waves is briefly discussed.
Discrete R Symmetries and Low Energy Supersymmetry
California at Santa Cruz, University of
R Symmetries and Low Energy Supersymmetry #12;Plan for Today: "New, Improved" Models of DynamicalDiscrete R Symmetries and Low Energy Supersymmetry UC Davis, 2011 Michael Dine Department on metastable susy breaking. Michael Dine Discrete R Symmetries and Low Energy Supersymmetry #12;Metastable
Compact discrete-time chaos generator circuit
Dudek, Piotr
Compact discrete-time chaos generator circuit P. Dudek and V.D. Juncu A three-transistor CMOS circuit is presented, with adjustable nonlinear characteristics, which can be used as a map that generates discrete-time chaotic signals. A method of constructing a chaos generator using two map circuits is also
Quasicrystals with discrete support and spectrum
Nir Lev; Alexander Olevskii
2015-09-08
We proved recently that a measure on R, whose support and spectrum are both uniformly discrete sets, must have a periodic structure. Here we show that this is not the case if the support and the spectrum are just discrete closed sets.
Quantum Walks and discrete Gauge Theories
Pablo Arnault; Fabrice Debbasch
2015-10-19
A particular example is produced to prove that quantum walks can be used to simulate full-fledged discrete gauge theories. A new family of $(1 + 2)$-dimensional walks is introduced and its continuous limit is shown to coincide with the dynamics of a Dirac fermion coupled to arbitrary electromagnetic fields. The electromagnetic interpretation is extended beyond the continuous limit by proving that these DTQWs exhibit an exact discrete local $U(1)$ gauge invariance and possess a discrete gauge-invariant conserved current. A discrete gauge-invariant electromagnetic field is also constructed and that field is coupled to the conserved current by a discrete generalization of Maxwell equations. The dynamics of the DTQWs under crossed electric and magnetic fields is finally explored outside the continuous limit by numerical simulations. Bloch oscillations and the so-called ${\\bf E} \\times {\\bf B}$ drift are recovered in the weak-field limit. Localization is observed for some values of the gauge fields.
COHERENT DISCRETE EMBEDDINGS FOR LAGRANGIAN AND HAMILTONIAN SYSTEMS
COHERENT DISCRETE EMBEDDINGS FOR LAGRANGIAN AND HAMILTONIAN SYSTEMS by J. Cresson, I. Greff & C . . ........................................ 6 Part II. Discrete variational embedding of Lagrangian systems . . ...................... 7 4. -- Lagrangian systems, Hamiltonian systems, variational integrators, discrete embeddings, numerical schemes, FEM
Identification and Estimation of a Discrete Game of Complete Information
Bajari, Patrick
We discuss the identification and estimation of discrete games of complete information. Following Bresnahan and Reiss (1990, 1991), a discrete game is a generalization of a standard discrete choice model where utility ...
Ken-ichi Maruno; Gino Biondini
2005-04-09
We present a class of solutions of the two-dimensional Toda lattice equation, its fully discrete analogue and its ultra-discrete limit. These solutions demonstrate the existence of soliton resonance and web-like structure in discrete integrable systems such as differential-difference equations, difference equations and cellular automata (ultra-discrete equations).
Continuum and discrete models for unbalanced woven fabrics
Angela Madeo; Gabriele Barbagallo; Marco Valerio D'Agostino; Philippe Boisse
2015-09-15
The classical models used for describing the behavior of woven fabrics do not fully account for the whole set of phenomena that occur during the testing of such materials. This lack of precision is mainly due to the absence of energy terms related to the microstructural properties of the fabric and, in particular, to the bending stiffness of the yarns. In this paper it is shown that in the unbalanced fabrics the different bending stiffnesses of the warp and weft yarns produce macroscopic effects that are extremely visible as, for example, the asymmetric S-shape during a Bias Extension Test (BET). We propose to introduce a constrained micromorphic model and a discrete model that are able to account for i) the angle variation between warp and weft tows, ii) the unbalance in the bending stiffness of the yarns and iii) the relative slipping of the tows. The constrained micromorphic model is framed in the spirit of the Principle of Virtual Powers for the equilibrium of continuum bodies. A suitable constraint is introduced by means of Lagrange multipliers in the strain energydens ity and the resulting constrained model tends a particular second gradientone. The main advantage of using such constrained micromorphic model is that the kinematical and traction boundary conditions that can be imposed on the boundary of the considered body take a natural and unique meaning. The discrete model is set up by opportunely interconnecting Euler-Bernoulli beams with different bending stiffnesses in the two directions by means of rotational and translational elastic springs. The main advantage of such discrete model is that the slipping of the tows is described in a rather realistic way. Suitable numerical simulations are presented for both the continuum and the discrete models and a comparison between the simulations and the experimental results is made showing a definitely good agreement.
Discrete Fourier-based Correlations for Entanglement Detection
Ryo Namiki; Yuuki Tokunaga
2012-06-06
We introduce two forms of correlations on two $d$-level (qudit) systems for entanglement detection. The correlations can be measured via experimentally tractable two local measurement settings and their separable bounds are determined by discrete Fourier-based uncertainty relations. They are useful to estimate lower bounds of the Schmidt number in order to clarify generation of a genuine qudit entanglement. We also present inseparable conditions for multi-qudit systems associated with the qudit stabilizer formalism as another role of the correlations on the inseparability problem.
Atmospheric Transport of Radionuclides
Crawford, T.V.
2003-03-03
The purpose of atmospheric transport and diffusion calculations is to provide estimates of concentration and surface deposition from routine and accidental releases of pollutants to the atmosphere. This paper discusses this topic.
Discrete element modelling of cementitious materials
Brown, Nicholas John
2013-07-01
This thesis presents a new bonded particle model that accurately predicts the wideranging behaviour of cementitious materials. There is an increasing use of the Discrete Element Method (DEM) to study the behaviour of ...
ADAPTIVE DISCRETIZATION OF AN INTEGRODIFFERENTIAL EQUATION
Larsson, Stig
ADAPTIVE DISCRETIZATION OF AN INTEGROÂDIFFERENTIAL EQUATION MODELING QUASIÂSTATIC FRACTIONAL ORDER VISCOELASTICITY Klas Adolfsson # Mikael Enelund ## Stig Larsson ### # Department of Applied Mechanics, Chalmers Mechanics, Chalmers University of Technology, SE--412 96 GË?oteborg, Sweden, mikael
Atmospheric sampling glow discharge ionization source
McLuckey, S.A.; Glish, G.L.
1989-07-18
An atmospheric sampling glow discharge ionization source that can be used in combination with an analytical instrument which operates at high vacuum, such as a mass spectrometer. The atmospheric sampling glow discharge ionization source comprises a chamber with at least one pair of electrodes disposed therein, an inlet for a gaseous sample to be analyzed and an outlet communicating with an analyzer which operates at subatmospheric pressure. The ionization chamber is maintained at a pressure below atmospheric pressure, and a voltage difference is applied across the electrodes to induce a glow discharge between the electrodes, so that molecules passing through the inlet are ionized by the glow discharge and directed into the analyzer. The ionization source accepts the sample under atmospheric pressure conditions and processes it directly into the high vacuum instrument, bridging the pressure gap and drawing off unwanted atmospheric gases. The invention also includes a method for analyzing a gaseous sample using the glow discharge ionization source described above. 3 figs.
Symmetric Instantons and Discrete Hitchin Equations
Ward, R S
2015-01-01
Self-dual Yang-Mills instantons on $R^4$ correspond to algebraic ADHM data. This paper describes how to specialize such ADHM data so that the instantons have a $T^2$ symmetry, and this in turn motivates an integrable discrete version of the 2-dimensional Hitchin equations. It is analogous to the way in which the ADHM data for $S^1$-symmetric instantons, or hyperbolic BPS monopoles, may be viewed as a discretization of the Nahm equations.
Atmospheric chemistry and global change
Prather, MJ
1999-01-01
and particles. Thus Atmospheric Chemistry and Global Changethe future of atmospheric chemistry. BROWSINGS Tornadothe complexity of atmospheric chemistry well, but trips a
Energy Levels of "Hydrogen Atom" in Discrete Time Dynamics
Andrei Khrennikov; Yaroslav Volovich
2006-04-27
We analyze dynamical consequences of a conjecture that there exists a fundamental (indivisible) quant of time. In particular we study the problem of discrete energy levels of hydrogen atom. We are able to reconstruct potential which in discrete time formalism leads to energy levels of unperturbed hydrogen atom. We also consider linear energy levels of quantum harmonic oscillator and show how they are produced in the discrete time formalism. More generally, we show that in discrete time formalism finite motion in central potential leads to discrete energy spectrum, the property which is common for quantum mechanical theory. Thus deterministic (but discrete time!) dynamics is compatible with discrete energy levels.
Energy Levels of "Hydrogen Atom" in Discrete Time Dynamics
Khrennikov, A; Khrennikov, Andrei; Volovich, Yaroslav
2006-01-01
We analyze dynamical consequences of a conjecture that there exists a fundamental (indivisible) quant of time. In particular we study the problem of discrete energy levels of hydrogen atom. We are able to reconstruct potential which in discrete time formalism leads to energy levels of unperturbed hydrogen atom. We also consider linear energy levels of quantum harmonic oscillator and show how they are produced in the discrete time formalism. More generally, we show that in discrete time formalism finite motion in central potential leads to discrete energy spectrum, the property which is common for quantum mechanical theory. Thus deterministic (but discrete time!) dynamics is compatible with discrete energy levels.
Thomas K. Gaisser
2005-02-18
Starting with an historical review, I summarize the status of calculations of the flux of atmospheric neutrinos and how they compare to measurements.
Wave Packets in Discrete Quantum Phase Space
Jang Young Bang; Micheal S Berger
2008-11-06
The properties of quantum mechanics with a discrete phase space are studied. The minimum uncertainty states are found, and these states become the Gaussian wave packets in the continuum limit. With a suitably chosen Hamiltonian that gives free particle motion in the continuum limit, it is found that full or approximate periodic time evolution can result. This represents an example of revivals of wave packets that in the continuum limit is the familiar free particle motion on a line. Finally we examine the uncertainty principle for discrete phase space and obtain the correction terms to the continuum case.
Optical Intensity Interferometry through Atmospheric Turbulence
Peng Kian Tan; Aik Hui Chan; Christian Kurtsiefer
2015-12-29
Conventional ground-based astronomical observations suffer from image distortion due to atmospheric turbulence. This can be minimized by choosing suitable geographic locations or adaptive optical techniques, and avoided altogether by using orbital platforms outside the atmosphere. One of the promises of optical intensity interferometry is its independence from atmospherically induced phase fluctuations. By performing narrowband spectral filtering on sunlight and conducting temporal intensity interferometry using actively quenched avalanche photon detectors (APDs), the Solar $g^{(2)}(\\tau)$ signature was directly measured. We observe an averaged photon bunching signal of $g^{(2)}(\\tau) = 1.693 \\pm 0.003$ from the Sun, consistently throughout the day despite fluctuating weather conditions, cloud cover and elevation angle. This demonstrates the robustness of the intensity interferometry technique against atmospheric turbulence and opto-mechanical instabilities, and the feasibility to implement measurement schemes with both large baselines and long integration times.
Oceanography and Atmospheric Sciences
Kurapov, Alexander
Oceanography and Atmospheric Sciences 19592009 WayneBurt. #12;Oceanography and Atmospheric in Oceanography (TENOC). Wayne Burt immediately responds with proposal to President Strand of Oregon State College to start a graduate Department of Oceanography. 1959 Oregon State Board of Higher Education approves
On the discretization of nonholonomic dynamics in $\\mathbb{R}^n$
Fernando Jimenez; Juergen Scheurle
2014-07-08
In this paper we explore the nonholonomic Lagrangian setting of mechanical systems in local coordinates on finite-dimensional configuration manifolds. We prove existence and uniqueness of solutions by reducing the basic equations of motion to a set of ordinary differential equations on the underlying distribution manifold $D$. Moreover, we show that any $D-$preserving discretization may be understood as beeing generated by the exact evolution map of a time-periodic non-autonomous perturbation of the original continuous-time nonholonomic system. By means of discretizing the corresponding Lagrange-d'Alembert principle, we construct geometric integrators for the original nonholonomic system. We give precise conditions under which these integrators generate a discrete flow preserving the distribution $D$. Also, we derive corresponding consistency estimates. Finally, we carefully treat the example of the nonholonomic particle, showing how to discretize the equations of motion in a reasonable way, particularly regarding the nonholonomic constraints. The exploration in this paper lays the ground to analyze the dynamics of appropriate discretizations of nonholonomic mechnical systems in the Lagrangian framework and to relate that dynamics to the dynamics of the original nonholonomic systems. We postpone this analysis to a series of forthcoming papers.
Stability of discrete breathers in magnetic metamaterials
Pelinovsky, Dmitry
Stability of discrete breathers in magnetic metamaterials Dmitry Pelinovsky1 and Vassilis Rothos2 1 describing magnetic metamaterials which consist of periodic arrays of split- ring resonators [4, 7]: ¨qn + V criterion to the multi-site breathers in magnetic metamaterials. 2 Formalism In what follows, we shall use
Chow's Team Petri Net Models discrete event
Kaber, David B.
", and "high" plate contents CELISCA: collection of physiology data based on NCSU prototype Output1 CELISCA: collection of physiology data based on New NCSU prototype Output2 #12;k Chow's Team Petri Net Models discrete event stochastic models (set fixed time interval updates
DISCRETE BREATHERS -RECENT RESULTS AND APPLICATIONS
Flach, Sergej
of Complex Systems, NÂ¨othnitzer Str. 38, D-01187 Dresden, Germany E-mail: flach energy thresholds in lattice dimensions d 2, models with ana- lytic solutions and compact solutions the past decade1,2,3 . The discreteness of space - i.e. the usage of a spatial lattice - is crucial
Comment on ``Discrete Boltzmann Equation for Microfluidics''
Luo, Li-Shi
Comment on ``Discrete Boltzmann Equation for Microfluidics'' In a recent Letter [1], Li and Kwok use a lattice Boltzmann equation (LBE) for microfluidics. Their main claim is that an LBE model for microfluidics can be constructed based on the ``Bhatnagar-Gross-Kooky [sic]'' model by including ``the
On the discrete bicycle transformation S. Tabachnikov
Tabachnikov, Sergei
On the discrete bicycle transformation S. Tabachnikov E. Tsukerman 1 Introduction The motivation for this paper comes from the study of a simple model of bicycle motion. The bicycle is modeled as an oriented segment in the plane of fixed length , the wheelbase of the bicycle. The motion is constrained so
Global discretization of continuous attributes as preprocessing for machine learning
Chmielewski, M. R.; Grzymala-Busse, Jerzy W.
1996-11-01
data sets with discrete attributes. Methods of discretization restricted to single continuous attributes will be called local, while methods that simultaneously convert all continuous attributes will be called global. in this paper, a method...
Defining Employee Perceptions of Discretion: When, Where, and How
Thompson, Rebecca Jean
2013-12-10
The construct employee discretion has been researched under many labels (e.g., flexibility, autonomy). As a result, employee discretion has been operationalized differently across multiple streams of research leading to construct deficiency...
Miki, Hiroshi; Tsujimoto, Satoshi
2011-01-01
Discrete spectral transformations of skew orthognal polynomials are presented. From these spectral transformations, it is shown that the corresponding discrete integrable systems are derived both in 1+1 dimension and in 2+1 dimension. Especially in the 2+1 dimensional case, the corresponding system can be extended to 2x2 matrix form. The factorization theorem of the skew-Christoffel kernel in random matrix theory is presented as a by-product of these transformations.
Hiroshi Miki; Hiroaki Goda; Satoshi Tsujimoto
2012-02-29
Discrete spectral transformations of skew orthogonal polynomials are presented. From these spectral transformations, it is shown that the corresponding discrete integrable systems are derived both in 1+1 dimension and in 2+1 dimension. Especially in the (2+1)-dimensional case, the corresponding system can be extended to 2x2 matrix form. The factorization theorem of the Christoffel kernel for skew orthogonal polynomials in random matrix theory is presented as a by-product of these transformations.
Ensemble Atmospheric Dispersion Modeling
Addis, R.P.
2002-06-24
Prognostic atmospheric dispersion models are used to generate consequence assessments, which assist decision-makers in the event of a release from a nuclear facility. Differences in the forecast wind fields generated by various meteorological agencies, differences in the transport and diffusion models, as well as differences in the way these models treat the release source term, result in differences in the resulting plumes. Even dispersion models using the same wind fields may produce substantially different plumes. This talk will address how ensemble techniques may be used to enable atmospheric modelers to provide decision-makers with a more realistic understanding of how both the atmosphere and the models behave.
Discrete mechanics, optimal control and formation flying spacecraft
Patrick, George
Discrete mechanics, optimal control and formation flying spacecraft Oliver Junge Center-BlÂ¨obaum partially supported by the CRC 376 Oliver Junge Discrete mechanics, optimal control and formation flying spacecraft p.1 #12;Outline mechanical optimal control problem direct discretization of the variational
Inverse problem with transmission eigenvalues for the discrete Schrödinger equation
Tuncay Aktosun; Vassilis G. Papanicolaou
2015-01-28
The discrete Schr\\"odinger equation with the Dirichlet boundary condition is considered on a half-line lattice when the potential is real valued and compactly supported. The inverse problem of recovery of the potential from the so-called transmission eigenvalues is analyzed. The Marchenko method and the Gel'fand-Levitan method are used to solve the inverse problem uniquely, except in one "unusual" case where the sum of the transmission eigenvalues is equal to a certain integer related to the support of the potential. It is shown that in the unusual case there may be a unique solution corresponding to certain sets of transmission eigenvalues, there may be a finite number of distinct potentials for some sets of transmission eigenvalues, or there may be infinitely many potentials for some sets of transmission eigenvalues. The theory presented is illustrated with several explicit examples.
Thermal depinning of fluxons in discrete Josephson rings
Mazo, J. J.; Naranjo, F.; Segall, K.
2008-11-01
We study the thermal depinning of single fluxons in rings made of Josephson junctions. Due to thermal fluctuations a fluxon can be excited from its energy minima and move through the array, causing a voltage across each junction. We find that for the initial depinning, the fluxon behaves as a single particle and follows a Kramers-type escape law. However, under some conditions this single-particle description breaks down. At low values of the discreteness parameter and low values of the damping, the depinning rate is larger than what the single-particle result would suggest. In addition, for some values of the parameters the fluxon can undergo low-voltage diffusion before switching to the high-voltage whirling mode. This type of diffusion is similar to phase diffusion in a single junction but occurs without frequency-dependent damping. We study the switching to the whirling state as well.
Extinction dynamics of a discrete population in an oasis
Berti, Stefano; Vergni, Davide; Vulpiani, Angelo
2015-01-01
Understanding the conditions ensuring the persistence of a population is an issue of primary importance in population biology. The first theoretical approach to the problem dates back to the 50's with the KiSS (after Kierstead, Slobodkin and Skellam) model, namely a continuous reaction-diffusion equation for a population growing on a patch of finite size $L$ surrounded by a deadly environment with infinite mortality -- i.e. an oasis in a desert. The main outcome of the model is that only patches above a critical size allow for population persistence. Here, we introduce an individual-based analogue of the KiSS model to investigate the effects of discreteness and demographic stochasticity. In particular, we study the average time to extinction both above and below the critical patch size of the continuous model and investigate the quasi-stationary distribution of the number of individuals for patch sizes above the critical threshold.
Toxicity of atmospheric aerosols on marine phytoplankton
2009-01-01
address: Center for Atmospheric Chemistry Study, Departmenttween phytoplankton, atmospheric chemistry, and climate areno. 12 ? 4601– 4605 CHEMISTRY Atmospheric aerosol deposition
Autumn 2014 Atmospheric Circulation
Doty, Sharon Lafferty
to perform atmospheric chemistry measurements in this remote region of ubiquitous oil and gas drilling 30 days they raised $12,000, enough to support Maria's travel to Utah and to cover the costs
Modelling and numerical approximation of a 2.5D set of equations for mesoscale atmospheric processes
Kalise, Dante
2011-01-01
The set of 3D inviscid primitive equations for the atmosphere is dimensionally reduced by a Discontinuous Galerkin discretization in one horizontal direction. The resulting model is a 2D system of balance laws where with a source term depending on the layering procedure and the choice of coupling fluxes, which is established in terms of upwind considerations. The "2.5D" system is discretized via a WENO-TVD scheme based in a flux limiter centered approach. We study four tests cases related to atmospheric phenomena to analyze the physical validity of the model.
AVERAGES ALONG POLYNOMIAL SEQUENCES IN DISCRETE NILPOTENT GROUPS: SINGULAR RADON TRANSFORMS
Magyar, Akos
AVERAGES ALONG POLYNOMIAL SEQUENCES IN DISCRETE NILPOTENT GROUPS: SINGULAR RADON TRANSFORMS can consider discrete maximal Radon transforms, which have applications to pointwise ergodic theo- rems, and discrete singular Radon transforms. In this paper we prove L2 boundedness of discrete
Effects of Changing Atmospheric Conditions on Wind Turbine Performance (Poster)
Clifton, A.
2012-12-01
Multi-megawatt, utility-scale wind turbines operate in turbulent and dynamic winds that impact turbine performance in ways that are gradually becoming better understood. This poster presents a study made using a turbulent flow field simulator (TurbSim) and a Turbine aeroelastic simulator (FAST) of the response of a generic 1.5 MW wind turbine to changing inflow. The turbine power output is found to be most sensitive to wind speed and turbulence intensity, but the relationship depends on the wind speed with respect to the turbine's rated wind speed. Shear is found to be poorly correlated to power. A machine learning method called 'regression trees' is used to create a simple model of turbine performance that could be used as part of the wind resource assessment process. This study has used simple flow fields and should be extended to more complex flows, and validated with field observations.
Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]
2004-07-08
This Notice ensures that DOE uniformly meets the requirements of the Homeland Security Advisory System outlined in Homeland Security Presidential Directive-3, Threat Conditions and Associated Protective Measures, dated 3-11-02, and provides responses specified in Presidential Decision Directive 39, U.S. Policy on Counterterrorism (U), dated 6-21-95. It cancels DOE N 473.8, Security Conditions, dated 8-7-02. Extended until 7-7-06 by DOE N 251.64, dated 7-7-05 Cancels DOE N 473.8
13, 1479714822, 2013 Atmospheric waves
Lovejoy, Shaun
.5194/acpd-13-14797-2013 © Author(s) 2013. CC Attribution 3.0 License. Sciences ss Atmospheric Chemistry and Physics OpenAccess Atmospheric Chemistry and Physics OpenAccess Discussions Atmospheric Measurement s Discussions This discussion paper is/has been under review for the journal Atmospheric Chemistry and Physics
Observations of Exoplanet Atmospheres
Crossfield, Ian J M
2015-01-01
Detailed characterization of an extrasolar planet's atmosphere provides the best hope for distinguishing the makeup of its outer layers, and the only hope for understanding the interplay between initial composition, chemistry, dynamics & circulation, and disequilibrium processes. In recent years, some areas have seen rapid progress while developments in others have come more slowly and/or have been hotly contested. This article gives an observer's perspective on the current understanding of extrasolar planet atmospheres prior to the considerable advances expected from the next generation of observing facilities. Atmospheric processes of both transiting and directly-imaged planets are discussed, including molecular and atomic abundances, cloud properties, thermal structure, and planetary energy budgets. In the future we can expect a continuing and accelerating stream of new discoveries, which will fuel the ongoing exoplanet revolution for many years to come.
Condition assessment of nonlinear processes
Hively, Lee M. (Philadelphia, TN); Gailey, Paul C. (Athens, OH); Protopopescu, Vladimir A. (Knoxville, TN)
2002-01-01
There is presented a reliable technique for measuring condition change in nonlinear data such as brain waves. The nonlinear data is filtered and discretized into windowed data sets. The system dynamics within each data set is represented by a sequence of connected phase-space points, and for each data set a distribution function is derived. New metrics are introduced that evaluate the distance between distribution functions. The metrics are properly renormalized to provide robust and sensitive relative measures of condition change. As an example, these measures can be used on EEG data, to provide timely discrimination between normal, preseizure, seizure, and post-seizure states in epileptic patients. Apparatus utilizing hardware or software to perform the method and provide an indicative output is also disclosed.
Novel coupling scheme to control dynamics of coupled discrete systems
Snehal M. Shekatkar; G. Ambika
2015-08-08
We present a new coupling scheme to control spatio-temporal patterns and chimeras on 1-d and 2-d lattices and random networks of discrete dynamical systems. The scheme involves coupling with an external lattice or network of damped systems. When the system network and external network are set in a feedback loop, the system network can be controlled to a homogeneous steady state or synchronized periodic state with suppression of the chaotic dynamics of the individual units. The control scheme has the advantage that its design does not require any prior information about the system dynamics or its parameters and works effectively for a range of parameters of the control network. We analyze the stability of the controlled steady state or amplitude death state of lattices using the theory of circulant matrices and Routh-Hurwitz's criterion for discrete systems and this helps to isolate regions of effective control in the relevant parameter planes. The conditions thus obtained are found to agree well with those obtained from direct numerical simulations in the specific context of lattices with logistic map and Henon map as on-site system dynamics. We show how chimera states developed in an experimentally realizable 2-d lattice can be controlled using this scheme. We propose this mechanism can provide a phenomenological model for the control of spatio-temporal patterns in coupled neurons due to non-synaptic coupling with the extra cellular medium. We extend the control scheme to regulate dynamics on random networks and adapt the master stability function method to analyze the stability of the controlled state for various topologies and coupling strengths.
Sevostianov, Igor
and recommended properties of the plasti®cator are derived under the condition that material should possessOverall properties of composites with physically non-linear discrete phase I. Sevostianov a,*, V elastic matrix and visco-plastic inclusions. Dense hydroxyapatite is considered as the matrix material
Validation of Discrete Framework for the Design of Fiber-Reinforced Soil and J. G. Zornberg2
Zornberg, Jorge G.
the performance under seismic conditions. GRI-18 Geosynthetics Research and Development in Progress #12;The designValidation of Discrete Framework for the Design of Fiber-Reinforced Soil C. Li1 and J. G. Zornberg2 conventionally designed using homogenized approaches. This has possibly compromised a rational basis for design
Fancher, Robert H.
1997-01-01
This study used discrete event simulation to model the personnel recruiting process for a U.S. Army recruiting company. Actual data from the company was collected and used to build the simulation model. The model is run under various conditions...
Compartmentalization analysis using discrete fracture network models
La Pointe, P.R.; Eiben, T.; Dershowitz, W.; Wadleigh, E.
1997-08-01
This paper illustrates how Discrete Fracture Network (DFN) technology can serve as a basis for the calculation of reservoir engineering parameters for the development of fractured reservoirs. It describes the development of quantitative techniques for defining the geometry and volume of structurally controlled compartments. These techniques are based on a combination of stochastic geometry, computational geometry, and graph the theory. The parameters addressed are compartment size, matrix block size and tributary drainage volume. The concept of DFN models is explained and methodologies to compute these parameters are demonstrated.
Coherence properties of discrete static kinks
H. Landa
2010-02-01
A chain of interacting particles subject also to a nonlinear on-site potential admits stable soliton-like configurations : static kinks. The linear normal-modes around such a kink contain a discrete set of localized, gap-separated modes. Quantization of the Hamiltonian in these modes results in an interacting system of phonons. We investigate numerically the coherence properties of such localized modes at low temperatures using a non-Markovian master equation. We show that low decoherence rates can be achieved in these nonlinear configurations for a surprisingly long time. If realized in the ion trap, kink internal modes may be advantageously used for Quantum Information Processing.
Quantumness of discrete Hamiltonian cellular automata
Hans-Thomas Elze
2014-07-08
We summarize a recent study of discrete (integer-valued) Hamiltonian cellular automata (CA) showing that their dynamics can only be consistently defined, if it is linear in the same sense as unitary evolution described by the Schr\\"odinger equation. This allows to construct an invertible map between such CA and continuous quantum mechanical models, which incorporate a fundamental scale. Presently, we emphasize general aspects of these findings, the construction of admissible CA observables, and the existence of solutions of the modified dispersion relation for stationary states.
Autumn 2012 Atmospheric Circulation
Doty, Sharon Lafferty
wind, and accumulated precipitation at a designated city. Forecasts are made over a two-week period Department 1 The UW Atmospheric Sciences spring forecast contest has been an annual tradition there will be a marine push or a convergence zone wrecking their forecast for maximum temperature and precipitation
Laboratory for Atmospheric and
Mojzsis, Stephen J.
Laboratory for Atmospheric and Space Physics Activity Report 2013 University of Colorado at Boulder from the Naval Research Center and the Air Force Cambridge Research Laboratory (now the Phillips Laboratory), the University of Colorado formed a research group called the Upper Air Laboratory (UAL
Laboratory for Atmospheric and
Mojzsis, Stephen J.
Laboratory for Atmospheric and Space Physics Activity Report 2012 University of Colorado at Boulder from the Naval Research Center and the Air Force Cambridge Research Laboratory (now the Phillips Laboratory), the University of Colorado formed a research group called the Upper Air Laboratory (UAL
Laboratory for Atmospheric and
Mojzsis, Stephen J.
Laboratory for Atmospheric and Space Physics Activity Report 2008 University of Colorado at Boulder, Jet Propulsion Laboratory) LASP: A Brief History In 1946-47, a handful of American universities joined Laboratory (now the Phillips Laboratory), the University of Colorado formed a research group called the Upper
Laboratory for Atmospheric and
Mojzsis, Stephen J.
1 Laboratory for Atmospheric and Space Physics Activity Report 2010 University of Colorado from the Na- val Research Center and the Air Force Cambridge Research Laboratory (now the Phillips Laboratory), the University of Colorado formed a research group called the Upper Air Laboratory (UAL
ATMOSPHERIC CHEMISTRY AND PHYSICS
Brandenburg, Axel
of electronic formats. Some content that appears in print may not be available in electronic formats. For more information about Wiley products, visit our web site at www.wiley.com. Library of Congress Cataloging components of the atmosphere, nitrogen, oxygen, water, carbon dioxide, and the noble gases. In the late
Galactic discrete sources of high energy neutrinos
W. Bednarek; G. F. Burgio; T. Montaruli
2004-04-27
We review recently developed models of galactic discrete sources of high energy neutrinos. Some of them are based on a simple rescaling of the TeV $\\gamma$-ray fluxes from recently detected galactic sources, such as, shell-type supernova remnants or pulsar wind nebulae. Others present detailed and originally performed modeling of processes occurring close to compact objects, i.e. neutron stars and low mass black holes, which are supposed to accelerate hadrons close to dense matter and radiation fields. Most of the models considered in this review optimistically assume that the energy content in relativistic hadrons is equal to a significant part of the maximum observable power output in specific sources, i.e. typically $\\sim 10%$. This may give a large overestimation of the neutrino fluxes. This is the case of models which postulate neutrino production in hadron-photon collisions already at the acceleration place, due to the likely $e^\\pm$ pair plasma domination. Models postulating neutrino production in hadron-hadron collisions avoid such problems and therefore seem to be more promising. The neutrino telescopes currently taking data have not detected any excess from discrete sources yet, although some models could already be constrained by the limits they are providing.
Lowest-rank Solutions of Continuous and Discrete Lyapunov ...
2012-10-08
Lyapunov equations are of great importance but generally diffi- cult to achieve in ... of the discrete Lyapunov inequality can be efficiently solved by a linear ...
Lowest-rank Solutions of Continuous and Discrete Lyapunov ...
Ziyan Luo
2012-10-09
Oct 9, 2012 ... Abstract: The low-rank solutions of continuous and discrete Lyapunov equations are of great importance but generally difficult to achieve in ...
Efficient energy stable schemes with spectral discretization in space ...
2012-04-03
We construct energy stable schemes for the time discretization of the highly ... Fundamentally, the gradient energy density loses its convexity (see a proof in the
Dual Transform Domain Echo Canceller for Discrete Multitone Systems
Champagne, Benoît
Dual Transform Domain Echo Canceller for Discrete Multitone Systems Neda Ehtiati and Beno Email:{neda.ehtiati,benoit.champagne}@mcgill.ca Abstract--In communication systems where full
ANALYTICAL MODELS OF EXOPLANETARY ATMOSPHERES. I. ATMOSPHERIC DYNAMICS VIA THE SHALLOW WATER SYSTEM
Heng, Kevin; Workman, Jared E-mail: jworkman@coloradomesa.edu
2014-08-01
Within the context of exoplanetary atmospheres, we present a comprehensive linear analysis of forced, damped, magnetized shallow water systems, exploring the effects of dimensionality, geometry (Cartesian, pseudo-spherical, and spherical), rotation, magnetic tension, and hydrodynamic and magnetic sources of friction. Across a broad range of conditions, we find that the key governing equation for atmospheres and quantum harmonic oscillators are identical, even when forcing (stellar irradiation), sources of friction (molecular viscosity, Rayleigh drag, and magnetic drag), and magnetic tension are included. The global atmospheric structure is largely controlled by a single key parameter that involves the Rossby and Prandtl numbers. This near-universality breaks down when either molecular viscosity or magnetic drag acts non-uniformly across latitude or a poloidal magnetic field is present, suggesting that these effects will introduce qualitative changes to the familiar chevron-shaped feature witnessed in simulations of atmospheric circulation. We also find that hydrodynamic and magnetic sources of friction have dissimilar phase signatures and affect the flow in fundamentally different ways, implying that using Rayleigh drag to mimic magnetic drag is inaccurate. We exhaustively lay down the theoretical formalism (dispersion relations, governing equations, and time-dependent wave solutions) for a broad suite of models. In all situations, we derive the steady state of an atmosphere, which is relevant to interpreting infrared phase and eclipse maps of exoplanetary atmospheres. We elucidate a pinching effect that confines the atmospheric structure to be near the equator. Our suite of analytical models may be used to develop decisively physical intuition and as a reference point for three-dimensional magnetohydrodynamic simulations of atmospheric circulation.
Differential atmospheric tritium sampler
Griesbach, O.A.; Stencel, J.R.
1987-10-02
An atmospheric tritium sampler is provided which uses a carrier gas comprised of hydrogen gas and a diluting gas, mixed in a nonexplosive concentration. Sample air and carrier gas are drawn into and mixed in a manifold. A regulator meters the carrier gas flow to the manifold. The air sample/carrier gas mixture is pulled through a first moisture trap which adsorbs water from the air sample. The moisture then passes through a combustion chamber where hydrogen gas in the form of H/sub 2/ or HT is combusted into water. The manufactured water is transported by the air stream to a second moisture trap where it is adsorbed. The air is then discharged back into the atmosphere by means of a pump.
Bayerschen, E; Wulfinghoff, S; Weygand, D; Böhlke, T
2015-01-01
The gradient crystal plasticity framework of Wulfinghoff et al. [53] incorporating an equivalent plastic strain and grain boundary yielding, is extended with additional grain boundary hardening. By comparison to averaged results from many discrete dislocation dynamics (DDD) simulations of an aluminum type tricrystal under tensile loading, the new hardening parameter in the continuum model is calibrated. It is shown that although the grain boundaries (GBs) in the discrete simulations are impenetrable, an infinite GB yield strength corresponding to microhard GB conditions, is not applicable in the continuum model. A combination of a finite GB yield strength with an isotropic bulk Voce hardening relation alone also fails to model the plastic strain profiles obtained by DDD. Instead, a finite GB yield strength in combination with GB hardening depending on the equivalent plastic strain at the GBs is shown to give a better agreement to DDD results. The differences in the plastic strain profiles obtained in DDD simu...
Twisted X-rays: incoming waveforms yielding discrete diffraction patterns for helical structures
Friesecke, Gero; Jüstel, Dominik
2015-01-01
Conventional X-ray methods use incoming plane waves and result in discrete diffraction patterns when scattered at crystals. Here we find, by a systematic method, incoming waveforms which exhibit discrete diffraction patterns when scattered at helical structures. As examples we present simulated diffraction patterns of carbon nanotubes and tobacco mosaic virus. The new incoming waveforms, which we call twisted waves due to their geometric shape, are found theoretically as closed-form solutions to Maxwell's equations. The theory of the ensuing diffraction patterns is developed in detail. A twisted analogue of the Von Laue condition is seen to hold, with the peak locations encoding the symmetry and the helix parameters, and the peak intensities indicating the electronic structure in the unit cell. If suitable twisted X-ray sources can in the future be realized experimentally, it appears from our mathematical results that they will provide a powerful tool for directly determining the detailed atomic structure of ...
Kansa, E., E-mail: edwardjkansa@netzero.com [Computational Sciences, LLC, 8000 Madison Blvd., Madison, AL 35758-2035 (United States); Shumlak, U., E-mail: shumlak@uw.edu [Computational Sciences, LLC, 8000 Madison Blvd., Madison, AL 35758-2035 (United States); Aerospace and Energetics Research Program, University of Washington, Box 352250, Seattle, WA 98195 (United States); Tsynkov, S., E-mail: tsynkov@math.ncsu.edu [Computational Sciences, LLC, 8000 Madison Blvd., Madison, AL 35758-2035 (United States); Department of Mathematics, North Carolina State University, Box 8205, Raleigh, NC 27695 (United States)
2013-02-01
Confining dense plasma in a field reversed configuration (FRC) is considered a promising approach to fusion. Numerical simulation of this process requires setting artificial boundary conditions (ABCs) for the magnetic field because whereas the plasma itself occupies a bounded region (within the FRC coils), the field extends from this region all the way to infinity. If the plasma is modeled using single fluid magnetohydrodynamics (MHD), then the exterior magnetic field can be considered quasi-static. This field has a scalar potential governed by the Laplace equation. The quasi-static ABC for the magnetic field is obtained using the method of difference potentials, in the form of a discrete Calderon boundary equation with projection on the artificial boundary shaped as a parallelepiped. The Calderon projection itself is computed by convolution with the discrete fundamental solution on the three-dimensional Cartesian grid.
Atmospheric Chemistry Theodore S. Dibble
Dibble, Theodore
SYLLABUS FOR Atmospheric Chemistry FCH 511 Fall 2014 Theodore S. Dibble Professor of Chemistry 421 in Required Text Seinfeld, J. H. and Pandis, S. N. Atmospheric Chemistry and Physics: From Air Pollution nineteenth year at ESF, and my seventeenth year teaching FCH 511 (Atmospheric Chemistry). I have done a lot
Lifetimes and eigenstates in atmospheric chemistry
Prather, Michael J
1994-01-01
Perturbation dynamics in atmospheric chemistry. J. Geophys.isotopic variations in atmospheric chemistry. Geophys. Res.M. et al. 2001 Atmospheric chemistry and greenhouse gases (
Atmospheric chemistry of an Antarctic volcanic plume
2010-01-01
L. , et al. (2010), Atmospheric chemistry results from theI. , et al. (2006), Atmospheric chemistry of a 33 – 34 hourvolcanic eruptions on atmospheric chemistry, Chem. Geol. ,
Information storage capacity of discrete spin systems
Beni Yoshida
2012-12-24
Understanding the limits imposed on information storage capacity of physical systems is a problem of fundamental and practical importance which bridges physics and information science. There is a well-known upper bound on the amount of information that can be stored reliably in a given volume of discrete spin systems which are supported by gapped local Hamiltonians. However, all the previously known systems were far below this theoretical bound, and it remained open whether there exists a gapped spin system that saturates this bound. Here, we present a construction of spin systems which saturate this theoretical limit asymptotically by borrowing an idea from fractal properties arising in the Sierpinski triangle. Our construction provides not only the best classical error-correcting code which is physically realizable as the energy ground space of gapped frustration-free Hamiltonians, but also a new research avenue for correlated spin phases with fractal spin configurations.
Discrete solitons and vortices on anisotropic lattices
Kevrekidis, P.G. [Department of Mathematics and Statistics, University of Massachusetts, Amherst, Massachusetts 01003-4515 (United States); Frantzeskakis, D.J. [Department of Physics, University of Athens, Panepistimiopolis, Zografos, Athens 15784 (Greece); Carretero-Gonzalez, R. [Nonlinear Dynamical Systems Group, Department of Mathematics and Statistics, and Computational Science Research Center, San Diego State University, San Diego, California 92182-7720 (United States); Malomed, B.A. [Department of Interdisciplinary Studies, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); Bishop, A.R. [Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2005-10-01
We consider the effects of anisotropy on solitons of various types in two-dimensional nonlinear lattices, using the discrete nonlinear Schroedinger equation as a paradigm model. For fundamental solitons, we develop a variational approximation that predicts that broad quasicontinuum solitons are unstable, while their strongly anisotropic counterparts are stable. By means of numerical methods, it is found that, in the general case, the fundamental solitons and simplest on-site-centered vortex solitons ('vortex crosses') feature enhanced or reduced stability areas, depending on the strength of the anisotropy. More surprising is the effect of anisotropy on the so-called 'super-symmetric' intersite-centered vortices ('vortex squares'), with the topological charge S equal to the square's size M: we predict in an analytical form by means of the Lyapunov-Schmidt theory, and confirm by numerical results, that arbitrarily weak anisotropy results in dramatic changes in the stability and dynamics in comparison with the degenerate, in this case, isotropic, limit.
A superintegrable discrete harmonic oscillator based on bivariate Charlier polynomials
Vincent X. Genest; Hiroshi Miki; Luc Vinet; Guofu Yu
2015-11-30
A simple discrete model of the two dimensional isotropic harmonic oscillator is presented. It is superintegrable with su(2) as its symmetry algebra. It is constructed with the help of the algebraic properties of the bivariate Charlier polyno-mials. This adds to the other discrete superintegrable models of the oscillator based on Krawtchouk and Meixner orthogonal polynomials in several variables.
Nash Equilibria in Discrete Routing Games with Convex Latency Functions
Mavronicolas, Marios
Nash Equilibria in Discrete Routing Games with Convex Latency Functions Martin Gairing1 , Thomas L 20537, Nicosia CY-1678, Cyprus. mavronic@ucy.ac.cy Abstract. We study Nash equilibria in a discrete, this is the first time that mixed Nash equilibria for routing games have been studied in combination with non
Mechanical Integrators Derived from a Discrete Variational Principle
Marsden, Jerrold
Mechanical Integrators Derived from a Discrete Variational Principle Jerey M. Wendlandt1;2 Mechanical Engineering, University of California at Berkeley, Berkeley, CA 94720, USA Jerrold E. Marsden3 for mechanical system simulation are created by using discrete algorithms to approximate the continuous equations
Discrete Fourier transform in nanostructures using scattering Michael N. Leuenbergera)
Flatte, Michael E.
Discrete Fourier transform in nanostructures using scattering Michael N. Leuenbergera) and Michael that the discrete Fourier transform DFT can be performed by scattering a coherent particle or laser beam off the initial vector into the two-dimensional potential by means of electric gates, the Fourier
GRADIENT THEORY FOR PLASTICITY VIA HOMOGENIZATION OF DISCRETE DISLOCATIONS
Garroni, Adriana
GRADIENT THEORY FOR PLASTICITY VIA HOMOGENIZATION OF DISCRETE DISLOCATIONS ADRIANA GARRONI theory for plasticity from a model of discrete dislocations. We restrict our analysis to the case of a cylindrical symmetry for the crystal in exam, so that the mathematical formulation will involve a two
MS Thesis Defense A Combined Discrete-dislocation/Scale-
Grujicic, Mica
MS Thesis Defense A Combined Discrete-dislocation/Scale- dependent Crystal Plasticity Analysis of Deformation and Fracture in Nanomaterials A Combined Discrete-dislocation/Scale- dependent Crystal Plasticity der Giessen, Needleman 1995) Crystal Plasticity Model Results and ComparisonII. Micro-beam Bending
EQUILIBRIUM RECONSTRUCTION FROM DISCRETE MAGNETIC MEASUREMENTS IN A TOKAMAK
Faugeras, Blaise
EQUILIBRIUM RECONSTRUCTION FROM DISCRETE MAGNETIC MEASUREMENTS IN A TOKAMAK Blaise Faugeras (joint of the equilibrium in a Tokamak from discrete magnetic mea- surements. In order to solve this inverse problem we of a plasma in a Tokamak [1]. The state variable of interest in the modelization of such an equilibrium under
Discrete Applied Mathematics 85 (1998) 59-70 MATHEMATICS
Fomin, Fedor V.
1998-01-01
ELSEYIER DISCRETE APPLIED Discrete Applied Mathematics 85 (1998) 59-70 MATHEMATICS Helicopter problem on a graph in which one cop in a helicopter flying from vertex to vertex tries to catch the robber. In each of the following steps, Cop moves (flies by helicopter) to some vertex (not necessarily adjacent
Model Transformation with Hierarchical Discrete-Event Control
Model Transformation with Hierarchical Discrete- Event Control Thomas Huining Feng Electrical, by the author(s). All rights reserved. Permission to make digital or hard copies of all or part of this work permission. #12;Model Transformation with Hierarchical Discrete-Event Control by Huining Feng B.S. (Nanjing
DISCRETE DUALITY FINITE VOLUME SCHEMES FOR DOUBLY NONLINEAR DEGENERATE
operators 17 3.4. Penalization operator 19 3.5. Discrete convection operator 20 3.6. Projection operators establish the existence and uniqueness of entropy solutions. We then turn to the construction and analysis and well-posedness 5 3. Discrete duality finite volume (DDFV) schemes 13 3.1. Construction of "double
Utility Maximization under Model Uncertainty in Discrete Time
Nutz, Marcel
Utility Maximization under Model Uncertainty in Discrete Time Marcel Nutz January 14, 2014 Abstract We give a general formulation of the utility maximization problem under nondominated model uncertainty in discrete time and show that an optimal portfolio exists for any utility function
Discrete curvature and the Gauss-Bonnet theorem
Joakim Arnlind; Jens Hoppe; Gerhard Huisken
2010-01-13
For matrix analogues of embedded surfaces we define discrete curvatures and Euler characteristics, and a non-commutative Gauss--Bonnet theorem is shown to follow. We derive simple expressions for the discrete Gauss curvature in terms of matrices representing the embedding coordinates, and provide a large class of explicit examples illustrating the new notions.
September 2011 Discrete Wheeler-DeWitt Equation
Hamber, Herbert W.
September 2011 Discrete Wheeler-DeWitt Equation Herbert W. Hamber 1 Institut des Hautes Etudes, Cambridge CB3 0JG, United Kingdom. ABSTRACT We present a discrete form of the Wheeler-DeWitt equation, with the solutions to the lattice equations providing a suitable approximation to the continuum wave functional
ISS-Lyapunov Functions for Discontinuous Discrete-Time Systems
Paris-Sud XI, Université de
1 ISS-Lyapunov Functions for Discontinuous Discrete-Time Systems Lars Gr¨une and Christopher M. Kellett Abstract Input-to-State Stability (ISS) and the ISS-Lyapunov function have proved to be useful- ous discrete-time dynamics, we investigate ISS-Lyapunov functions for such systems. ISS-Lyapunov
Institute of Operations Research Discrete Optimization and Logistics
Al Hanbali, Ahmad
Institute of Operations Research Discrete Optimization and Logistics 1 Prof. Dr. Stefan Nickel Health Care Logistics: Overview Health Care Logistics 11/28/2013 #12;Institute of Operations Research Discrete Optimization and Logistics 2 Prof. Dr. Stefan Nickel Health Care Logistics: Overview Health Care
Methane present in an extrasolar planet atmosphere
Mark R. Swain; Gautam Vasisht; Giovanna Tinetti
2008-02-07
Molecules present in exoplanetary atmospheres are expected to strongly influence the atmospheric radiation balance, trace dynamical and chemical processes, and indicate the presence of disequilibrium effects. Since molecules have the potential to reveal the exoplanet atmospheric conditions and chemistry, searching for them is a high priority. The rotational-vibrational transition bands of water, carbon monoxide, and methane are anticipated to be the primary sources of non-continuum opacity in hot-Jovian planets. Since these bands overlap in wavelength, and the corresponding signatures from them are weak, decisive identification requires precision infrared spectroscopy. Here we report on a near-infrared transmission spectrum of the planet HD 189733b showing the presence of methane. Additionally, a resolved water-vapour band at 1.9 microns confirms the recent claim of water in this object. On thermochemical grounds, carbon-monoxide is expected to be abundant in the upper atmosphere of hot-Jovian exoplanets; thus the detection of methane rather than carbon-monoxide in such a hot planet could signal the presence of a horizontal chemical gradient away from the permanent dayside, or it may imply an ill-understood photochemical mechanisms that leads to an enhancement of methane.
d li d l iModeling and Solution Issues in Discrete Event Simulationin Discrete Event Simulation
Grossmann, Ignacio E.
// / Flexsim: http://www.flexsim.com/ Witness: http://www.witness-for-simulation.com/ ProModel: httpd li d l iModeling and Solution Issues in Discrete Event Simulationin Discrete Event Simulation of a real system. Simulation helps to predict performance test ideas eliminateSimulation helps to predict
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.TheoryTuesday, August 10, 20102016Study (CHAPS)Archive CampaignListAtmospheric Heat
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.TheoryTuesday, August 10, 20102016Study (CHAPS)Archive CampaignListAtmospheric
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnical Report:Speeding accessby a contractor ofvarDOE PAGES11 PPPL-Atmospheric PSF
Three-body continuum wave functions with a box boundary condition
E. Garrido
2015-05-06
In this work we investigate the connection between discretized three-body continuum wave functions, in particular via a box boundary condition, and the wave functions computed with the correct asymptotics. The three-body wave functions are in both cases obtained by means of the adiabatic expansion method. The information concerning all the possible incoming and outgoing channels, which appears naturally when the continuum is not discretized, seems to be lost when the discretization is implemented. In this work we show that both methods are fully equivalent, and the full information contained in the three-body wave function is actually preserved in the discrete spectrum. Therefore, in those cases when the asymptotic behaviour is not known analytically, i.e., when the Coulomb interaction is involved, the discretization technique can be safely used.
Discrete Scale Relativity And SX Phoenicis Variable Stars
R. L. Oldershaw
2009-06-18
Discrete Scale Relativity proposes a new symmetry principle called discrete cosmological self-similarity which relates each class of systems and phenomena on a given Scale of nature's discrete cosmological hierarchy to the equivalent class of analogue systems and phenomena on any other Scale. The new symmetry principle can be understood in terms of discrete scale invariance involving the spatial, temporal and dynamic parameters of all systems and phenomena. This new paradigm predicts a rigorous discrete self-similarity between Stellar Scale variable stars and Atomic Scale excited atoms undergoing energy-level transitions and sub-threshold oscillations. Previously, methods for demonstrating and testing the proposed symmetry principle have been applied to RR Lyrae, Delta Scuti and ZZ Ceti variable stars. In the present paper we apply the same analytical methods and diagnostic tests to a new class of variable stars: SX Phoenicis variables. Double-mode pulsators are shown to provide an especially useful means of testing the uniqueness and rigor of the conceptual principles and discrete self-similar scaling of Discrete Scale Relativity.
An efficient permeability scaling-up technique applied to the discretized flow equations
Urgelli, D.; Ding, Yu
1997-08-01
Grid-block permeability scaling-up for numerical reservoir simulations has been discussed for a long time in the literature. It is now recognized that a full permeability tensor is needed to get an accurate reservoir description at large scale. However, two major difficulties are encountered: (1) grid-block permeability cannot be properly defined because it depends on boundary conditions; (2) discretization of flow equations with a full permeability tensor is not straightforward and little work has been done on this subject. In this paper, we propose a new method, which allows us to get around both difficulties. As the two major problems are closely related, a global approach will preserve the accuracy. So, in the proposed method, the permeability up-scaling technique is integrated in the discretized numerical scheme for flow simulation. The permeability is scaled-up via the transmissibility term, in accordance with the fluid flow calculation in the numerical scheme. A finite-volume scheme is particularly studied, and the transmissibility scaling-up technique for this scheme is presented. Some numerical examples are tested for flow simulation. This new method is compared with some published numerical schemes for full permeability tensor discretization where the full permeability tensor is scaled-up through various techniques. Comparing the results with fine grid simulations shows that the new method is more accurate and more efficient.
Wave Equations for Discrete Quantum Gravity
Gudder, Stan
2015-01-01
This article is based on the covariant causal set ($c$-causet) approach to discrete quantum gravity. A $c$-causet $x$ is a finite partially ordered set that has a unique labeling of its vertices. A rate of change on $x$ is described by a covariant difference operator and this operator acting on a wave function forms the left side of the wave equation. The right side is given by an energy term acting on the wave function. Solutions to the wave equation corresponding to certain pairs of paths in $x$ are added and normalized to form a unique state. The modulus squared of the state gives probabilities that a pair of interacting particles is at various locations given by pairs of vertices in $x$. We illustrate this model for a few of the simplest nontrivial examples of $c$-causets. Three forces are considered, the attractive and repulsive electric forces and the strong nuclear force. Large models get much more complicated and will probably require a computer to analyze.
Wave Equations for Discrete Quantum Gravity
Stan Gudder
2015-08-29
This article is based on the covariant causal set ($c$-causet) approach to discrete quantum gravity. A $c$-causet $x$ is a finite partially ordered set that has a unique labeling of its vertices. A rate of change on $x$ is described by a covariant difference operator and this operator acting on a wave function forms the left side of the wave equation. The right side is given by an energy term acting on the wave function. Solutions to the wave equation corresponding to certain pairs of paths in $x$ are added and normalized to form a unique state. The modulus squared of the state gives probabilities that a pair of interacting particles is at various locations given by pairs of vertices in $x$. We illustrate this model for a few of the simplest nontrivial examples of $c$-causets. Three forces are considered, the attractive and repulsive electric forces and the strong nuclear force. Large models get much more complicated and will probably require a computer to analyze.
The Transmission Property of the Discrete Heisenberg Ferromagnetic Spin Chain
Qing Ding; Wei Lin
2008-01-14
We present a mechanism for displaying the transmission property of the discrete Heisenberg ferromagnetic spin chain (DHF) via a geometric approach. By the aid of a discrete nonlinear Schr\\"odinger-like equation which is the discrete gauge equivalent to the DHF, we show that the determination of transmitting coefficients in the transmission problem is always bistable. Thus a definite algorithm and general stochastic algorithms are presented. A new invariant periodic phenomenon of the non-transmitting behavior for the DHF, with a large probability, is revealed by an adoption of various stochastic algorithms.
Generalized discrete orbit function transforms of affine Weyl groups
Tomasz Czy?ycki; Ji?í Hrivnák
2014-11-14
The affine Weyl groups with their corresponding four types of orbit functions are considered. Two independent admissible shifts, which preserve the symmetries of the weight and the dual weight lattices, are classified. Finite subsets of the shifted weight and the shifted dual weight lattices, which serve as a sampling grid and a set of labels of the orbit functions, respectively, are introduced. The complete sets of discretely orthogonal orbit functions over the sampling grids are found and the corresponding discrete Fourier transforms are formulated. The eight standard one-dimensional discrete cosine and sine transforms form special cases of the presented transforms.
An Excursion-Theoretic Approach to Stability of Discrete-Time Stochastic Hybrid Systems
Chatterjee, Debasish, E-mail: chatterjee@control.ee.ethz.ch [ETH Zuerich, ETL I19 (Switzerland); Pal, Soumik, E-mail: soumik@math.washington.edu [University of Washington, Department of Mathematics (United States)
2011-04-15
We address stability of a class of Markovian discrete-time stochastic hybrid systems. This class of systems is characterized by the state-space of the system being partitioned into a safe or target set and its exterior, and the dynamics of the system being different in each domain. We give conditions for L{sub 1}-boundedness of Lyapunov functions based on certain negative drift conditions outside the target set, together with some more minor assumptions. We then apply our results to a wide class of randomly switched systems (or iterated function systems), for which we give conditions for global asymptotic stability almost surely and in L{sub 1}. The systems need not be time-homogeneous, and our results apply to certain systems for which functional-analytic or martingale-based estimates are difficult or impossible to get.
José Alfredo Cańizo
2007-11-19
Under the condition of detailed balance and some additional restrictions on the size of the coefficients, we identify the equilibrium distribution to which solutions of the discrete coagulation-fragmentation system of equations converge for large times, thus showing that there is a critical mass which marks a change in the behavior of the solutions. This was previously known only for particular cases as the generalized Becker-D\\"oring equations. Our proof is based on an inequality between the entropy and the entropy production which also gives some information on the rate of convergence to equilibrium for solutions under the critical mass.
Switching Between Discrete and Continuous Models To Predict Genetic Activity
Weld, Daniel S.
Molecular biologists use a variety of models when they predict the behavior of genetic systems. A discrete model of the behavior of individual macromolecular elements forms the foundation for their theory of each system. ...
Analysis of steel silo structures on discrete supports
Li, Hongyu
The objective of this thesis is to broaden current knowledge of the strength and buckling/collapse of shells, with special reference to steel silo structures on discrete supports, and thus to provide design guidance of ...
Research on Combinatorial Statistics: Crossings and Nestings in Discrete Structures
Poznanovikj, Svetlana
2011-10-21
We study the distribution of combinatorial statistics that exhibit a structure of crossings and nesting in various discrete structures, in particular, in set partitions, matchings, and fillings of moon polyominoes with entries 0 and 1. Let pi and y...
AC transmission system planning choosing lines from a discrete set
Gilbertson, Eric W.
2013-04-24
Transmission system planning (TSP) is a difficult nonlinear optimization problem involving non-convex quadratic terms, as well as discrete variables. We extend prior results for linear relaxations, drawing on a preliminary ...
Design of discrete-time filters for efficient implementation
Wei, Dennis
2011-01-01
The cost of implementation of discrete-time filters is often strongly dependent on the number of non-zero filter coefficients or the precision with which the coefficients are represented. This thesis addresses the design ...
Discrete Feature Approach for Heterogeneous Reservoir Production Enhancement
Dershowitz, William S.; Curran, Brendan; Einstein, Herbert; LaPointe, Paul; Shuttle, Dawn; Klise, Kate
2002-07-26
The report presents summaries of technology development for discrete feature modeling in support of the improved oil recovery (IOR) for heterogeneous reservoirs. In addition, the report describes the demonstration of these technologies at project study sites.
2-D discrete element modeling of unconsolidated sandstones
Franquet Barbara, Javier Alejandro
2001-01-01
In this work unconsolidated sands saturated with heavy oil were modeled using a discrete element numerical model, (DEM). The DEM code was built in Mathematica ? programming language. The strain-stress behavior of biaxial ...
POLYHEDRAL REPRESENTATION OF DISCRETE MORSE ETHAN D. BLOCH
Bloch, Ethan
POLYHEDRAL REPRESENTATION OF DISCRETE MORSE FUNCTIONS ETHAN D. BLOCH Abstract. It is proved during a sabbatical when parts of this paper were written. 1 #12;2 ETHAN D. BLOCH Forman defines an index
Double-distribution-function discrete Boltzmann model for combustion
Chuandong Lin; Aiguo Xu; Guangcai Zhang; Yingjun Li
2015-11-11
A 2-dimensional discrete Boltzmann model for combustion is presented. Mathematically, the model is composed of two coupled discrete Boltzmann equations for two species and a phenomenological equation for chemical reaction process. Physically, the model is equivalent to a reactive Navier-Stokes model supplemented by a coarse-grained model for the thermodynamic nonequilibrium behaviours. This model adopts 16 discrete velocities. It works for both subsonic and supersonic combustion phenomena with flexible specific heat ratio. To discuss the physical accuracy of the coarse-grained model for nonequilibrium behaviours, three other discrete velocity models are used for comparisons. Numerical results are compared with analytical solutions based on both the first-order and second-order truncations of the distribution function. It is confirmed that the physical accuracy increases with the increasing moment relations needed by nonequlibrium manifestations. Furthermore, compared with the single distribution function model, this model can simulate more details of combustion.
Automatic Performance Optimization of the Discrete Fourier Transform
Franchetti, Franz
Automatic Performance Optimization of the Discrete Fourier Transform on Distributed Memory {franzf,pueschel}@ece.cmu.edu Abstract. This paper introduces a formal framework for automatically. Using a tagging mechanism and formula rewriting, we extend SPIRAL to automatically generate parallelized
Finding discrete logarithms with a set orbit distinguisher
International Association for Cryptologic Research (IACR)
or a prime order 1 #12;subgroup of an elliptic curve group, and a standard assumption in these groups outline algorithms for computing discrete logarithms. The theme in each case is that given a polynomial
Dual Domain Echo Cancellers for Multirate Discrete Multitone Systems
Champagne, Benoît
Dual Domain Echo Cancellers for Multirate Discrete Multitone Systems Neda Ehtiati and Beno Email:{neda.ehtiati, benoit.champagne}@mcgill.ca Abstract--Digital echo cancellers are used in duplex
On the solutions of generalized discrete Poisson Roman Werpachowski
On the solutions of generalized discrete Poisson equation Roman Werpachowski Center for Theoretical of the right-hand side g and will be analyzed elsewhere. 2 #12;2 Uniqueness theorem Theorem 1 Let x : Zd C
Resolution of grain scale interactions using the Discrete Element Method
Johnson, Scott M. (Scott Matthew), 1978-
2006-01-01
Granular materials are an integral part of many engineering systems. Currently, a popular tool for numerically investigating granular systems is the Discrete Element Method (DEM). Nearly all implementations of the DEM, ...
Nonlinear symmetric stability of planetary atmospheres
Bowman, J.C.; Shepherd, T.G.
1994-11-01
The energy-Casimir method is applied to the problem of symmetric stability in the context of a compressible, hydrostatic planetary atmosphere with a general equation of state. Linear stability criteria for symmetric disturbances to a zonally symmetric baroclinic flow are obtained. In the special case of a perfect gas the results of Stevens (1983) are recovered. Nonlinear stability conditions are also obtained that, in addition to implying linear stability, provide an upper bound on a certain positive-definite measure of disturbance amplitude.
Atmospheric fogging in underground mine airways
Gillies, A.D.S.; Schimmelpfennig
1983-04-01
Loss of visibility due to the occurrence of atmospheric fogging in underground mine airways can lead to longer travel times and loss of production efficiency, an increase in the frequency of vehicular and foot traffic accidents and difficulty in checking rock surfaces for instability and loose material. Where hot and humid surface air meets colder underground air, conditions for fog formation may be present. Further, suspended particulate matter from diesel exhausts or stoping operations together with slow movement of air along passageways may contribute to formation. This study describes an investigation being undertaken with the cooperation of Kennecott's Ozark Lead Co. to identify causes of the problem.
Direct measurement of yield stress of discrete materials
S. H. Ebrahimnazhad Rahbari; J. Vollmer; S. Herminghaus; M. Brinkmann
2012-06-09
We present a novel computational method for direct measurement of yield stress of discrete materials. The method is well-suited for the measurement of jamming phase diagram of a wide range of discrete particle systems such as granular materials, foams, and colloids. We further successfully apply the method to evaluate the jamming phase diagram of wet granular material in order to demonstrates the applicability of the model.
Space Science : Atmosphere Greenhouse Effect
Johnson, Robert E.
Space Science : Atmosphere Greenhouse Effect Part-5a Solar + Earth Spectrum IR Absorbers Grey Atmosphere Greenhouse Effect #12;Radiation: Solar and Earth Surface B"(T) Planck Ideal Emission Integrate and it emits Note: heat balance Fvis( = Fout = Te 4 z #12;(simple Greenhouse cont.) 0 1 2 3 4 Ground Space Top
chemistry and remote sensing.Atmospheric scientists apply physics, mathematics, and chemistry to understandAtmospheric science encompasses meteorology and climatology, as well as fields such as atmospheric the atmosphere and its interactions with land and sea. One of the goals of atmospheric science is to understand
Clear sky atmosphere at cm-wavelengths from climatology data
Lew, Bartosz
2015-01-01
We utilise ground-based, balloon-born and satellite climatology data to reconstruct site and season-dependent vertical profiles of precipitable water vapour (PWV). We use these profiles to numerically solve radiative transfer through the atmosphere, and derive atmospheric brightness temperature ($T_{\\rm atm}$) and optical depth ($\\tau$) at the centimetre wavelengths. We validate the reconstruction by comparing the model column PWV, with photometric measurements of PWV, performed in the clear sky conditions towards the Sun. Based on the measurements, we devise a selection criteria to filter the climatology data to match the PWV levels to the expectations of the clear sky conditions. We apply the reconstruction to the location of the Polish 32-metre radio telescope, and characterise $T_{\\rm atm}$ and $\\tau$ year-round, at selected frequencies. We also derive the zenith distance dependence for these parameters, and discuss shortcomings of using planar, single-layer, and optically thin atmospheric model approxima...
Department of Electrical Engineering and Computer Science Discrete Event Systems Group
Tilbury, Dawn
Department of Electrical Engineering and Computer Science 1 Discrete Event Systems Group A Discrete 2000 #12;Department of Electrical Engineering and Computer Science 2 Discrete Event Systems Group of Electrical Engineering and Computer Science 3 Discrete Event Systems Group Requirements for Industrial
Bounds for the price of discrete arithmetic Asian options M. Vanmaele
Vanmaele, Michčle
on discrete averaging which is the normal specification in real contracts. Discrete arithmetic Asian optionsBounds for the price of discrete arithmetic Asian options M. Vanmaele , G. Deelstra , J. Liinev , J.Goovaerts@econ.kuleuven.ac.be, Tel. +32 16 326750. #12;Bounds for the price of discrete arithmetic Asian options Abstract
The Discrete Operator Approach to the Numerical Solution of Partial Differential Equations
The Discrete Operator Approach to the Numerical Solution of Partial Differential Equations James C that performs a cer- tain calculation on a field. A field corresponds to any scalar or vector variable required = Discrete gradient operator I = Discrete integral operator L = Generic operator R = Discrete interpolant
DIVISION OF MARINE AND ATMOSPHERIC CHEMISTRY
Shyu, Mei-Ling
DIVISION OF MARINE AND ATMOSPHERIC CHEMISTRY The missions of the Division of Marine and Atmospheric Chemistry (MAC) are to carry out broadly based research on the chemistry of the atmosphere and marine and stratosphere. Atmospheric Chemistry Research activities in atmospheric chemistry and modeling are diverse
ATMOSPHERIC CHEMISTRY - RESPONSE TO HUMAN INFLUENCE
LOGAN, J; PRATHER, M; WOFSY, S; MCELROY, M
1978-01-01
Trans. II 70, 253. ATMOSPHERIC CHEMISTRY Clyne, M. A. A. &data for modelling atmospheric chemistry. NBS Technical NoteChem. 80, 2711. ATMOSPHERIC CHEMISTRY Sanadze, G. A. 1963 On
IMPROVED QUASISTEADYSTATEAPPROXIMATION METHODS FOR ATMOSPHERIC CHEMISTRY INTEGRATION #
Jay, Laurent O.
IMPROVED QUASISTEADYSTATEAPPROXIMATION METHODS FOR ATMOSPHERIC CHEMISTRY INTEGRATION # L. O. JAY QSSA are presented. Key words. atmospheric chemistry, sti# ordinary di#erential equations, quasi PII. S1064827595283033 1. Introduction. As our scientific understanding of atmospheric chemistry
Global atmospheric chemistry: Integrating over fractional cloud cover
Neu, Jessica L; Prather, Michael J; Penner, Joyce E
2007-01-01
trace gases and atmospheric chemistry, in Climate Change2007 Global atmospheric chemistry: Integrating over2007), Global atmospheric chemistry: Integrating over
Withers, Paul
aerobraking passes can be used to build up a picture of atmospheric conditions at a range of alti- tudes in the solar wind and solar photon flux. 1 #12;
Blackwell, William Joseph, 1971-
2002-01-01
This thesis addresses the problem of retrieving the temperature profile of the Earth's atmosphere from overhead infrared and microwave observations of spectral radiance in cloudy conditions. The contributions of the thesis ...
Infrared Observations of Exoplanet Atmospheres
Crossfield, Ian James Mills
2012-01-01
However, atmospheres of cool planets can still be studiedvia outgassing as the planet cools (Rogers & Seager 2010).at low resolution) and the cool, low-mass planet GJ 1214b (
Composition and Reactions of Atmospheric Aerosol Particles
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Composition and Reactions of Atmospheric Aerosol Particles Print Microscopic aerosol particles in the atmosphere contain carbonaceous components from mineral dust and combustion...
Laser Atmospheric Studies with VERITAS
C. M. Hui; for the VERITAS collaboration
2007-09-25
As a calibrated laser pulse propagates through the atmosphere, the amount of Rayleigh-scattered light arriving at the VERITAS telescopes can be calculated precisely. This technique was originally developed for the absolute calibration of ultra-high-energy cosmic-ray fluorescence telescopes but is also applicable to imaging atmospheric Cherenkov telescopes (IACTs). In this paper, we present two nights of laser data taken with the laser at various distances away from the VERITAS telescopes and compare it to Rayleigh scattering simulations.
Atmospheric science and power production
Randerson, D.
1984-07-01
This is the third in a series of scientific publications sponsored by the US Atomic Energy Commission and the two later organizations, the US Energy Research and Development Adminstration, and the US Department of Energy. The first book, Meteorology and Atomic Energy, was published in 1955; the second, in 1968. The present volume is designed to update and to expand upon many of the important concepts presented previously. However, the present edition draws heavily on recent contributions made by atmospheric science to the analysis of air quality and on results originating from research conducted and completed in the 1970s. Special emphasis is placed on how atmospheric science can contribute to solving problems relating to the fate of combustion products released into the atmosphere. The framework of this book is built around the concept of air-quality modeling. Fundamentals are addressed first to equip the reader with basic background information and to focus on available meteorological instrumentation and to emphasize the importance of data management procedures. Atmospheric physics and field experiments are described in detail to provide an overview of atmospheric boundary layer processes, of how air flows around obstacles, and of the mechanism of plume rise. Atmospheric chemistry and removal processes are also detailed to provide fundamental knowledge on how gases and particulate matter can be transformed while in the atmosphere and how they can be removed from the atmosphere. The book closes with a review of how air-quality models are being applied to solve a wide variety of problems. Separate analytics have been prepared for each chapter.
Atmospheric Radiation Measurement Program Science Plan
Ackerman, T
2004-10-31
The Atmospheric Radiation Measurement (ARM) Program has matured into one of the key programs in the U.S. Climate Change Science Program. The ARM Program has achieved considerable scientific success in a broad range of activities, including site and instrument development, atmospheric radiative transfer, aerosol science, determination of cloud properties, cloud modeling, and cloud parameterization testing and development. The focus of ARM science has naturally shifted during the last few years to an increasing emphasis on modeling and parameterization studies to take advantage of the long time series of data now available. During the next 5 years, the principal focus of the ARM science program will be to: Maintain the data record at the fixed ARM sites for at least the next five years. Improve significantly our understanding of and ability to parameterize the 3-D cloud-radiation problem at scales from the local atmospheric column to the global climate model (GCM) grid square. Continue developing techniques to retrieve the properties of all clouds, with a special focus on ice clouds and mixed-phase clouds. Develop a focused research effort on the indirect aerosol problem that spans observations, physical models, and climate model parameterizations. Implement and evaluate an operational methodology to calculate broad-band heating rates in the atmospheric columns at the ARM sites. Develop and implement methodologies to use ARM data more effectively to test atmospheric models, both at the cloud-resolving model scale and the GCM scale. Use these methodologies to diagnose cloud parameterization performance and then refine these parameterizations to improve the accuracy of climate model simulations. In addition, the ARM Program is actively developing a new ARM Mobile Facility (AMF) that will be available for short deployments (several months to a year or more) in climatically important regions. The AMF will have much of the same instrumentation as the remote facilities at ARM's Tropical Western Pacific and the North Slope of Alaska sites. Over time, this new facility will extend ARM science to a much broader range of conditions for model testing.
Representative Atmospheric Plume Development for Elevated Releases
Eslinger, Paul W.; Lowrey, Justin D.; McIntyre, Justin I.; Miley, Harry S.; Prichard, Andrew W.
2014-03-03
An atmospheric explosion of a low-yield nuclear device will produce a large number of radioactive isotopes, some of which can be measured with airborne detection systems. However, properly equipped aircraft may not arrive in the region where an explosion occurred for a number of hours after the event. Atmospheric conditions will have caused the radioactive plume to move and diffuse before the aircraft arrives. The science behind predicting atmospheric plume movement has advanced enough that the location of the maximum concentrations in the plume can be determined reasonably accurately in real time, or near real time. Given the assumption that an aircraft can follow a plume, this study addresses the amount of atmospheric dilution expected to occur in a representative plume as a function of time past the release event. The approach models atmospheric transport of hypothetical releases from a single location for every day in a year using the publically available HYSPLIT code. The effective dilution factors for the point of maximum concentration in an elevated plume based on a release of a non-decaying, non-depositing tracer can vary by orders of magnitude depending on the day of the release, even for the same number of hours after the release event. However, the median of the dilution factors based on releases for 365 consecutive days at one site follows a power law relationship in time, as shown in Figure S-1. The relationship is good enough to provide a general rule of thumb for estimating typical future dilution factors in a plume starting at the same point. However, the coefficients of the power law function may vary for different release point locations. Radioactive decay causes the effective dilution factors to decrease more quickly with the time past the release event than the dilution factors based on a non-decaying tracer. An analytical expression for the dilution factors of isotopes with different half-lives can be developed given the power law expression for the non-decaying tracer. If the power-law equation for the median dilution factor, Df, based on a non-decaying tracer has the general form Df=a?×t?^(-b) for time t after the release event, then the equation has the form Df=e^(-?t)×a×t^(-b) for a radioactive isotope, where ? is the decay constant for the isotope.
Are nonlinear discrete cellular automata compatible with quantum mechanics?
Hans-Thomas Elze
2015-05-14
We consider discrete and integer-valued cellular automata (CA). A particular class of which comprises "Hamiltonian CA" with equations of motion that bear similarities to Hamilton's equations, while they present discrete updating rules. The dynamics is linear, quite similar to unitary evolution described by the Schroedinger equation. This has been essential in our construction of an invertible map between such CA and continuous quantum mechanical models, which incorporate a fundamental discreteness scale. Based on Shannon's sampling theory, it leads, for example, to a one-to-one relation between quantum mechanical and CA conservation laws. The important issue of linearity of the theory is examined here by incorporating higher-order nonlinearities into the underlying action. These produce inconsistent nonlocal (in time) effects when trying to describe continuously such nonlinear CA. Therefore, in the present framework, only linear CA and local quantum mechanical dynamics are compatible.
Computer aided analysis and synthesis for discrete robust control systems
Setijawan, Bambang
1994-01-01
of an interval discrete system. . 4 Nyquist plot of the system with a constant controller k = -3. . . . . 5 Definition of encirclement. . Page 27 28 30 6 Definition of enclosed points and regions. . 7 Definition of the number of encirclement and enclosure... unstable 1 Re marginally stable Fig. 1. Stability region for discrete time systems A general control system is presented in the following figure, r e + controller C(z) PLANT G(z) Fig. 2. A general form of control systems Any physical process...
Discrete Cosmological Self-Similarity And Delta Scuti Stars
R. L. Oldershaw
2008-10-08
Within the context of a fractal paradigm that emphasizes nature's well-stratified hierarchical organization, the delta Scuti class of variable stars is investigated for evidence of discrete cosmological self-similarity. Methods that were successfully applied to the RR Lyrae class of variable stars are used to identify Atomic Scale analogues to delta Scuti stars and their relevant range of energy levels. The mass, pulsation mode and fundamental oscillation period of a well-studied delta Scuti star are shown to be quantitatively self-similar to the counterpart parameters of a uniquely identified Atomic Scale analogue. Several additional tests confirm the specificity of the discrete fractal relationship.
Methodology for characterizing modeling and discretization uncertainties in computational simulation
ALVIN,KENNETH F.; OBERKAMPF,WILLIAM L.; RUTHERFORD,BRIAN M.; DIEGERT,KATHLEEN V.
2000-03-01
This research effort focuses on methodology for quantifying the effects of model uncertainty and discretization error on computational modeling and simulation. The work is directed towards developing methodologies which treat model form assumptions within an overall framework for uncertainty quantification, for the purpose of developing estimates of total prediction uncertainty. The present effort consists of work in three areas: framework development for sources of uncertainty and error in the modeling and simulation process which impact model structure; model uncertainty assessment and propagation through Bayesian inference methods; and discretization error estimation within the context of non-deterministic analysis.
Chemistry of Atmospheric Brown Carbon Alexander Laskin,*,
Nizkorodov, Sergey
Chemistry of Atmospheric Brown Carbon Alexander Laskin,*, Julia Laskin,*, and Sergey A. Nizkorodov fraction of atmospheric aerosol and has profound effects on air quality, atmospheric chemistry, and climate of radiation through Earth's atmosphere. The cloud albedo effect, Special Issue: 2015 Chemistry in Climate
Millimeter Wavelength Brightness Fluctuations of the Atmosphere Above the South Pole
Bussmann, R S; Kuo, C L
2004-01-01
We report measurements of the millimeter wavelength brightness fluctuations produced by the atmosphere above the South Pole made with the Arcminute Cosmology Bolometer Array Receiver (ACBAR). The data span the 2002 Austral winter during which ACBAR was mounted on the Viper telescope at the South Pole. We recover the atmospheric signal in the presence of instrument noise by calculating the correlation between signals from distinct elements of the ACBAR bolometer array. With this method, it is possible to measure atmospheric brightness fluctuations with high SNR even under the most stable atmospheric conditions. The observed atmospheric signal is characterized by the parameters of the Komolgorov-Taylor (KT) model, which are the amplitude and power law exponent describing the atmospheric power spectrum, and the two components of the wind angular velocity at the time of the observation. The KT model is typically a good description of the observed fluctuations, and fits to the data produce values of the Komolgorov...
An active atmospheric methane sink in high Arctic mineral cryosols
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Lau, Maggie C.Y.; Stackhouse, B.; Layton, Alice C.; Chauhan, Archana; Vishnivetskaya, T. A.; Chourey, Karuna; Mykytczuk, N. C.S.; Bennett, Phil C.; Lamarche-Gagnon, G.; Burton, N.; et al
2015-04-14
The transition of Arctic carbon-rich cryosols into methane (CH?)-emitting wetlands due to global warming is a rising concern. However, the spatially predominant mineral cryosols and their CH? emission potential are poorly understood. Fluxes measured in situ and estimated under laboratory conditions coupled with -omics analysis indicate (1) mineral cryosols in the Canadian high Arctic contain atmospheric CH?-oxidizing bacteria; (2) the atmospheric CH? uptake flux increases with ground temperature; and, as a result, (3) the atmospheric CH? sink strength will increase by a factor of 5-30 as the Arctic warms by 5-15 °C over a century. We demonstrated that acidic mineralmore »cryosols have previously unrecognized potential of negative CH? feedback.« less
Atmospheric benzenoid emissions from plants rival those from fossil fuels
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Misztal, P. K.; Hewitt, C. N.; Wildt, J.; Blande, J. D.; Eller, A. S.D.; Fares, S.; Gentner, D. R.; Gilman, J. B.; Graus, M.; Greenberg, J.; et al
2015-07-13
Despite the known biochemical production of a range of aromatic compounds by plants and the presence of benzenoids in floral scents, the emissions of only a few benzenoid compounds have been reported from the biosphere to the atmosphere. Here, using evidence from measurements at aircraft, ecosystem, tree, branch and leaf scales, with complementary isotopic labeling experiments, we show that vegetation (leaves, flowers, and phytoplankton) emits a wide variety of benzenoid compounds to the atmosphere at substantial rates. Controlled environment experiments show that plants are able to alter their metabolism to produce and release many benzenoids under stress conditions. The functionsmore »of these compounds remain unclear but may be related to chemical communication and protection against stress. We estimate the total global secondary organic aerosol potential from biogenic benzenoids to be similar to that from anthropogenic benzenoids (~10 Tg y-1), pointing to the importance of these natural emissions in atmospheric physics and chemistry.« less
Physics in discrete spaces (A): Space-Time organization
P. Peretto
2010-12-29
We put forward a model of discrete physical space that can account for the structure of space- time, give an interpretation to the postulates of quantum mechanics and provide a possible explanation to the organization of the standard model of particles.
Leptonic Dirac CP Violation Predictions from Residual Discrete Symmetries
Girardi, I; Stuart, Alexander J; Titov, A V
2015-01-01
Assuming that the observed pattern of 3-neutrino mixing is related to the existence of a (lepton) flavour symmetry, corresponding to a non-Abelian discrete symmetry group $G_f$, and that $G_f$ is broken to specific residual symmetries $G_e$ and $G_\
Leptonic Dirac CP Violation Predictions from Residual Discrete Symmetries
I. Girardi; S. T. Petcov; Alexander J. Stuart; A. V. Titov
2015-09-08
Assuming that the observed pattern of 3-neutrino mixing is related to the existence of a (lepton) flavour symmetry, corresponding to a non-Abelian discrete symmetry group $G_f$, and that $G_f$ is broken to specific residual symmetries $G_e$ and $G_\
Nash Equilibria in Discrete Routing Games with Convex Latency Functions
Mavronicolas, Marios
Nash Equilibria in Discrete Routing Games with Convex Latency Functions Martin Gairing Thomas L is determined by an arbitrary non-decreasing, non-constant and convex latency function . In a Nash equilib- rium on the link it chooses. To evaluate Nash equilibria, we formulate Social Cost as the sum of the users
Dynamic Limit Growth Indices in Discrete Time Tomasz R. Bielecki
Heller, Barbara
Dynamic Limit Growth Indices in Discrete Time Tomasz R. Bielecki 1 bielecki@iit.edu Igor Cialenco 1, Illinois Institute of Technology, Chicago, 60616 IL, USA 2 Institute of Mathematics, Jagiellonian propose a new class of mappings, called Dynamic Limit Growth Indices, that are designed to measure
DISCRETE-CONTINUUM MODELING OF METAL MATRIX COMPOSITES PLASTICITY
Devincre, Benoit
. For this reason, the pre- diction of the plastic properties of Metal Matrix Composites (MMCs) is some- times for plastic properties. On the one hand, the FE code treats the boundary value problem and cares of the conDISCRETE-CONTINUUM MODELING OF METAL MATRIX COMPOSITES PLASTICITY S. Groh1, B. Devincre1, F. Feyel2
Discrete dissipative localized modes in nonlinear magnetic metamaterials
Discrete dissipative localized modes in nonlinear magnetic metamaterials Nikolay N. Rosanov,1 effects in. References and links 1. N. Engheta and R. W. Ziolkowski, eds. Electromagnetic Metamaterials. Gorkunov, I. V. Shadrivov, and Yu. S. Kivshar, "Metamaterial tuning by manip- ulation of near
Cryptanalyzing a discrete-time chaos synchronization secure communication system
Gonzalo Alvarez; Fausto Montoya; Miguel Romera; Gerardo Pastor
2003-11-21
This paper describes the security weakness of a recently proposed secure communication method based on discrete-time chaos synchronization. We show that the security is compromised even without precise knowledge of the chaotic system used. We also make many suggestions to improve its security in future versions.
Verification in Loosely Synchronous Queue-Connected Discrete Timed Automata
Dang, Zhe
, the expressive power of timed automata has many limitations in modeling, since many real-time systems are simply. We look at a model of a queue system that consists of the following components: 1. Two discrete timed model for investigating verification problems of real-time sys- tems (see [1, 30] for surveys). However
Verification in Loosely Synchronous QueueConnected Discrete Timed Automata ?
Dang, Zhe
, the expressive power of timed automata has many limitations in modeling, since many realÂtime systems are simply. We look at a model of a queue system that consists of the following components: 1. Two discrete timed model for investigating verification problems of realÂtime sysÂ tems (see [1, 30] for surveys). However
Discrete wave turbulence of rotational capillary water waves
Adrian Constantin; Elena Kartashova; Erik Wahlén
2010-05-12
We study the discrete wave turbulent regime of capillary water waves with constant non-zero vorticity. The explicit Hamiltonian formulation and the corresponding coupling coefficient are obtained. We also present the construction and investigation of resonance clustering. Some physical implications of the obtained results are discussed.
Hamiltonian dynamics and constrained variational calculus: continuous and discrete settings
Manuel de Leon; Fernando Jimenez; David Martin de Diego
2012-01-01
The aim of this paper is to study the relationship between Hamiltonian dynamics and constrained variational calculus. We describe both using the notion of Lagrangian submanifolds of convenient symplectic manifolds and using the so-called Tulczyjew's triples. The results are also extended to the case of discrete dynamics and nonholonomic mechanics. Interesting applications to geometrical integration of Hamiltonian systems are obtained.
ENHANCING DISCRETE CHOICE DEMAND MODELING FOR DECISION-BASED DESIGN
Chen, Wei
the Decision-Based Design framework. Even though demand modeling techniques exist in market research, little design, in particular that facilitates engineering decision-making. In market research, two major demand1 ENHANCING DISCRETE CHOICE DEMAND MODELING FOR DECISION-BASED DESIGN In Press of ASME Journal
A DISCRETE WAVELET ANALYSIS OF FREAK WAVES IN THE OCEAN
measurement of landslide-generated impulse waves was presented in [2]. In fact, the measured results of continuous wave recordings made in the Sea of Japan during 19861990 by the Ship Research Institute of JapanA DISCRETE WAVELET ANALYSIS OF FREAK WAVES IN THE OCEAN EN-BING LIN AND PAUL C. LIU Received 25
ADAPTIVE DISCRETIZATION OF AN INTEGRO-DIFFERENTIAL EQUATION
Larsson, Stig
ADAPTIVE DISCRETIZATION OF AN INTEGRO-DIFFERENTIAL EQUATION MODELING QUASI-STATIC FRACTIONAL ORDER VISCOELASTICITY Klas Adolfsson Mikael Enelund Stig Larsson Department of Applied Mechanics, Chalmers University of Technology, SEÂ412 96 GÂ¨oteborg, Sweden, klas.adolfsson@chalmers.se Department of Applied Mechanics
Energy-Efficient Discrete Cosine Transform on Ronald Scrofano
Jang, Ju-Wook
Energy-Efficient Discrete Cosine Transform on FPGAs Ronald Scrofano Department of Computer Science is brought to mobile devices, it becomes important that it is possible to calculate the DCT in an energy-efficient the DCT with a linear array of PEs. This design is optimized for energy efficiency. We analyze the energy
Inverses of Multivariate Polynomial Matrices using Discrete Convolution
Young, R. Michael
Inverses of Multivariate Polynomial Matrices using Discrete Convolution R. Lobo Dept. of Elec Raleigh, NC 27695 Abstract-- A new method for inversion of rectangular matrices in a multivariate to multivariate polynomial system of equations is the subject of intensive research and has major applications
Integrating a discrete motion model into GMM based background subtraction
Wolf, Christian
consecutive frames minimizing a global energy function taking into account spatial and temporal re- lationships. A discrete approximative optical-flow like motion model is integrated into the energy function, for instance for track- ing algorithms. Most existing methods build an explicit background model either using
Generic Average Modeling and Simulation of Discrete Controllers
be advantageous to have the capability of running AC analysis of digitally controlled power systems on a general is suggested for the design of discrete controllers for switch mode systems. I. INTRODUCTION The current, in principle, to large signal (time domain) analysis. However, classical control design methods in power
Topological horseshoes in travelling waves of discretized nonlinear wave equations
Chen, Yi-Chiuan, E-mail: YCChen@math.sinica.edu.tw [Institute of Mathematics, Academia Sinica, Taipei 10617, Taiwan (China)] [Institute of Mathematics, Academia Sinica, Taipei 10617, Taiwan (China); Chen, Shyan-Shiou, E-mail: sschen@ntnu.edu.tw [Department of Mathematics, National Taiwan Normal University, Taipei 11677, Taiwan (China)] [Department of Mathematics, National Taiwan Normal University, Taipei 11677, Taiwan (China); Yuan, Juan-Ming, E-mail: jmyuan@pu.edu.tw [Department of Financial and Computational Mathematics, Providence University, Shalu, Taichung 43301, Taiwan (China)] [Department of Financial and Computational Mathematics, Providence University, Shalu, Taichung 43301, Taiwan (China)
2014-04-15
Applying the concept of anti-integrable limit to coupled map lattices originated from space-time discretized nonlinear wave equations, we show that there exist topological horseshoes in the phase space formed by the initial states of travelling wave solutions. In particular, the coupled map lattices display spatio-temporal chaos on the horseshoes.
Wave-packet continuum discretization for quantum scattering
O. A. Rubtsova; V. I. Kukulin; V. N. Pomerantsev
2015-01-15
A general approach to a solution of few- and many-body scattering problems based on a continuum-discretization procedure is described in detail. The complete discretization of continuous spectrum is realized using stationary wave packets which are the normalized states constructed from exact non-normalized continuum states. Projecting the wave functions and all scattering operators like $t$-matrix, resolvent, etc. on such a wave-packet basis results in a formulation of quantum scattering problem entirely in terms of discrete elements and linear equations with regular matrices. It is demonstrated that there is a close relation between the above stationary wave packets and pseudostates which are employed often to approximate the scattering states with a finite $L_2$ basis. Such a fully discrete treatment of complicated few- and many-body scattering problems leads to significant simplification of their practical solution. Also we get finite-dimensional approximations for complicated operators like effective interactions between composite particles constructed via the Feshbach-type projection formalism. As illustrations to this general approach we consider several important particular problems including multichannel scattering and scattering in the three-nucleon system within the Faddeev framework.
Double-distribution-function discrete Boltzmann model for combustion
Chuandong Lin; Aiguo Xu; Guangcai Zhang; Yingjun Li
2015-06-21
A 2-dimensional discrete Boltzmann model for combustion is presented. Mathematically, the model is composed of two coupled discrete Boltzmann equations for two species and a phenomenological evolution equation for chemical reaction process. Physically, the model is equivalent to a Navier-Stokes model supplemented by a coarse-grained model for the thermodynamic nonequilibrium behaviours. This model adopts $16$ discrete velocities. It works for both subsonic and supersonic combustion phenomena with flexible specific heat ratio. To discuss the physical accuracy of the coarse-grained model for nonequilibrium behaviours, three other discrete velocity models are used for comparisons. Numerical results are compared with analytical solutions based on both the first-order and second-order truncations of the distribution function. It is confirmed that the physical accuracy increases with the increasing moment relations needed by nonequlibrium manifestations. Furthermore, a criterion of transition from incomplete to complete combustion is obtained. Compared with the single distribution function model, this model can simulate incomplete combustion, decomposition and combination reactions.
Cumulant expansions for atmospheric flows
Ait-Chaalal, Farid; Meyer, Bettina; Marston, J B
2015-01-01
The equations governing atmospheric flows are nonlinear, and consequently the hierarchy of cumulant equations is not closed. But because atmospheric flows are inhomogeneous and anisotropic, the nonlinearity may manifests itself only weakly through interactions of mean fields with disturbances such as thermals or eddies. In such situations, truncations of the hierarchy of cumulant equations hold promise as a closure strategy. We review how truncations at second order can be used to model and elucidate the dynamics of turbulent atmospheric flows. Two examples are considered. First, we study the growth of a dry convective boundary layer, which is heated from below, leading to turbulent upward energy transport and growth of the boundary layer. We demonstrate that a quasilinear truncation of the equations of motion, in which interactions of disturbances among each other are neglected but interactions with mean fields are taken into account, can successfully capture the growth of the convective boundary layer. Seco...
ATMOSPHERIC CIRCULATION OF BROWN DWARFS: JETS, VORTICES, AND TIME VARIABILITY
Zhang, Xi; Showman, Adam P.
2014-06-10
A variety of observational evidence demonstrates that brown dwarfs exhibit active atmospheric circulations. In this study we use a shallow-water model to investigate the global atmospheric dynamics in the stratified layer overlying the convective zone on these rapidly rotating objects. We show that the existence and properties of the atmospheric circulation crucially depend on key parameters including the energy injection rate and radiative timescale. Under conditions of strong internal heat flux and weak radiative dissipation, a banded flow pattern comprised of east-west jet streams spontaneously emerges from the interaction of atmospheric turbulence with the planetary rotation. In contrast, when the internal heat flux is weak and/or radiative dissipation is strong, turbulence injected into the atmosphere damps before it can self-organize into jets, leading to a flow dominated by transient eddies and isotropic turbulence instead. The simulation results are not very sensitive to the form of the forcing. Based on the location of the transition between jet-dominated and eddy-dominated regimes, we suggest that many brown dwarfs may exhibit atmospheric circulations dominated by eddies and turbulence (rather than jets) due to the strong radiative damping on these worlds, but a jet structure is also possible under some realistic conditions. Our simulated light curves capture important features from observed infrared light curves of brown dwarfs, including amplitude variations of a few percent and shapes that fluctuate between single-peak and multi-peak structures. More broadly, our work shows that the shallow-water system provides a useful tool to illuminate fundamental aspects of the dynamics on these worlds.
Withers, Paul
Observations of atmospheric tides on Mars at the season and latitude of the Phoenix atmospheric atmospheric entry of NASA's Phoenix Mars probe using Phoenix Atmospheric Structure Experiment (ASE) data atmospheric entry, Geophys. Res. Lett., 37, L24204, doi:10.1029/2010GL045382. 1. Introduction [2] Phoenix
Discrete dragline attachment induces aggregation in spiderlings of a solitary species
Theraulaz, Guy
Discrete dragline attachment induces aggregation in spiderlings of a solitary species RAPHAEL and the experimental data shows that the discrete pattern of silk dragline attachment is the key mechanism involved
Discrete Applied Mathematics 154 (2006) 16331639 www.elsevier.com/locate/dam
Hartke, Stephen
2006-01-01
Discrete Applied Mathematics 154 (2006) 16331639 www.elsevier.com/locate/dam Note The elimination. doi:10.1016/j.dam.2005.11.009 #12;1634 Stephen G. Hartke / Discrete Applied Mathematics 154 (2006
Semiclassical energy conditions
Martin-Moruno, Prado
2013-01-01
We present and develop several nonlinear energy conditions suitable for use in the semiclassical regime. In particular, we consider the recently formulated "flux energy condition" (FEC), and the novel "trace-of-square" (TOSEC) and "determinant" (DETEC) energy conditions. As we shall show, these nonlinear energy conditions behave much better than the classical linear energy conditions in the presence of semiclassical quantum effects. Moreover, whereas the quantum extensions of these nonlinear energy conditions seem to be quite widely satisfied as one enters the quantum realm, analogous quantum extensions are generally not useful for the linear classical energy conditions.
Pulsed atmospheric fluidized bed combustion
Not Available
1992-08-01
The general specifications for a Pulsed Atmospheric Fluidized Bed Combustor Design Report (PAFBC) plant are presented. The design tasks for the PAFBC are described in the following areas: Coal/Limestone preparation and feed system; pulse combustor; fluidized bed; boiler parts; and ash handling system.
Critical phenomena in atmospheric precipitation
Loss, Daniel
LETTERS Critical phenomena in atmospheric precipitation OLE PETERS1,2,3 * AND J. DAVID NEELIN3 1 convection and precipitation (the order parameter)--with correlated regions on scales of tens to hundreds the climatological mean by an order of magnitude or more. Moist convection and the accompanying precipitation have
FOURIER PAIRS OF DISCRETE SUPPORT WITH LITTLE STRUCTURE MIHAIL N. KOLOUNTZAKIS
Kolountzakis, Mihalis
FOURIER PAIRS OF DISCRETE SUPPORT WITH LITTLE STRUCTURE MIHAIL N. KOLOUNTZAKIS Abstract. We give line of discrete support, whose Fourier Transform is also a measure of discrete support, yet this Fourier pair cannot be constructed by repeatedly applying the Poisson Summation Formula finitely many
A discrete fourth-order Lidstone problem with parameters Douglas R. Anderson a,*, Feliz Minhs b
Anderson, Douglas R.
A discrete fourth-order Lidstone problem with parameters Douglas R. Anderson a,*, Feliz Minhós b Symmetric Green's function Fixed points Fourth-order Discrete Beam Lidstone Semipositone a b s t r a c discrete fourth-order Lidstone boundary value problem with dependence on two parameters are given, using
Finite-Time Stability of Discrete-Time Nonlinear Systems: Analysis and Design
Finite-Time Stability of Discrete-Time Nonlinear Systems: Analysis and Design S. Mastellone, P. Dorato, C. T. Abdallah Abstract-- Finite-time stability of nonlinear discrete-time systems is studied we propose a new analysis result for fi- nite time stability of deterministic and stochastic discrete
HIPPO_discrete_continuous_Users_Guide_20121130 1 Revision Date: November 30, 2012
Discrete Flask and GC Sample GHG, Halocarbon, and Hydrocarbon Data (R_20121129) Summary: This data set results. Each row of the data file contains the results for all of measurements of a discrete sample / laboratory made a particular discrete measurement: 1 =AWAS/U.Miami, 2 = NWAS/NOAA+CU, 3 = PantherMSD/NOAA, 4
CERNA WORKING PAPER SERIES Patent quality and value in discrete and cumulative innovation
Paris-Sud XI, Université de
1 CERNA WORKING PAPER SERIES Patent quality and value in discrete and cumulative innovation Justus,version2-16Nov2010 #12;2 Patent Quality and Value in Discrete and Cumulative Innovation Cerna Working the relationship between patent quality and patent value in discrete and cumulative innovation. Using factor
Controllers for Discrete Event Systems via P. Madhusudan 1 and P. S. Thiagarajan 2 ?
Parthasarathy, Madhusudan
Controllers for Discrete Event Systems via Morphisms P. Madhusudan 1 and P. S. Thiagarajan 2 ? 1 the problem of synthesising controllers for discrete event systems. Traditionally this problem is tackled therein. From the controlÂtheoretic perspective, the modelling of discreteÂevent systems (DES
Averages along polynomial sequences in discrete nilpotent groups: singular Radon transforms
Ionescu, Alexandru D; Wainger, Stephen
2012-01-01
We consider a class of operators defined by taking averages along polynomial sequences in discrete nilpotent groups. In this paper we prove $L^2$ boundedness of discrete singular Radon transforms along general polynomial sequences in discrete nilpotent groups of step 2.
Stanford University
The construction of discretely conservative finite volume schemes that also globally conserve conservation law u t + x f(u) = 0 is approximated by the semi-discrete conservative scheme duj dt + 1 x fj+1 2 shown that shock waves can be fully resolved by non-dissipative discretizations of this type with a fine
Vanderbei, Robert J., E-mail: rvdb@princeton.edu [Princeton University, Department of Operations Research and Financial Engineering (United States); P Latin-Small-Letter-Dotless-I nar, Mustafa C., E-mail: mustafap@bilkent.edu.tr [Bilkent University, Department of Industrial Engineering (Turkey); Bozkaya, Efe B. [Sabanc Latin-Small-Letter-Dotless-I University, Faculty of Administrative Sciences (Turkey)] [Sabanc Latin-Small-Letter-Dotless-I University, Faculty of Administrative Sciences (Turkey)
2013-02-15
An American option (or, warrant) is the right, but not the obligation, to purchase or sell an underlying equity at any time up to a predetermined expiration date for a predetermined amount. A perpetual American option differs from a plain American option in that it does not expire. In this study, we solve the optimal stopping problem of a perpetual American option (both call and put) in discrete time using linear programming duality. Under the assumption that the underlying stock price follows a discrete time and discrete state Markov process, namely a geometric random walk, we formulate the pricing problem as an infinite dimensional linear programming (LP) problem using the excessive-majorant property of the value function. This formulation allows us to solve complementary slackness conditions in closed-form, revealing an optimal stopping strategy which highlights the set of stock-prices where the option should be exercised. The analysis for the call option reveals that such a critical value exists only in some cases, depending on a combination of state-transition probabilities and the economic discount factor (i.e., the prevailing interest rate) whereas it ceases to be an issue for the put.
Implementation of Quantum and Classical Discrete Fractional Fourier Transforms
Steffen Weimann; Armando Perez-Leija; Maxime Lebugle; Robert Keil; Malte Tichy; Markus Gräfe; Rene Heilmann; Stefan Nolte; Hector Moya-Cessa; Gregor Weihs; Demetrios N. Christodoulides; Alexander Szameit
2015-07-31
Fourier transforms are ubiquitous mathematical tools in basic and applied sciences. We here report classical and quantum optical realizations of the discrete fractional Fourier transform, a generalization of the Fourier transform. In the integrated configuration used in our experiments, the order of the transform is mapped onto the longitudinal coordinate, thus opening up the prospect of simultaneously observing all Transformation orders. In the context of classical optics, we implement discrete fractional Fourier transforms, both integer and fractional, of exemplary wave functions and experimentally demonstrate the shift theorem. Moreover, we apply this approach in the quantum realm to transform separable and highly entangled biphoton wave functions. The proposed approach is versatile and could find applications in various fields where Fourier transforms are essential tools, such as quantum chemistry and biology, physics and mathematics.
Quantum Mechanics and Discrete Time from "Timeless" Classical Dynamics
H. -T. Elze
2003-07-03
We study classical Hamiltonian systems in which the intrinsic proper time evolution parameter is related through a probability distribution to the physical time, which is assumed to be discrete. - This is motivated by the ``timeless'' reparametrization invariant model of a relativistic particle with two compactified extradimensions. In this example, discrete physical time is constructed based on quasi-local observables. - Generally, employing the path-integral formulation of classical mechanics developed by Gozzi et al., we show that these deterministic classical systems can be naturally described as unitary quantum mechanical models. The emergent quantum Hamiltonian is derived from the underlying classical one. It is closely related to the Liouville operator. We demonstrate in several examples the necessity of regularization, in order to arrive at quantum models with bounded spectrum and stable groundstate.
Directed assembly of discrete gold nanoparticle groupings usingbranched DNA scaffolds
Claridge, Shelley A.; Goh, Sarah L.; Frechet, Jean M.J.; Williams, Shara C.; Micheel, Christine M.; Alivisatos, A. Paul
2004-09-14
The concept of self-assembled dendrimers is explored for the creation of discrete nanoparticle assemblies. Hybridization of branched DNA trimers and nanoparticle-DNA conjugates results in the synthesis of nanoparticle trimer and tetramer complexes. Multiple tetramer architectures are investigated, utilizing Au-DNA conjugates with varying secondary structural motifs. Hybridization products are analyzed by gel electrophoresis, and discrete bands are observed corresponding to structures with increasing numbers of hybridization events. Samples extracted from each band are analyzed by transmission electron microscopy, and statistics compiled from micrographs are used to compare assembly characteristics for each architecture. Asymmetric structures are also produced in which both 5 and 10 nm Au particles are assembled on branched scaffolds.
A study of discrete and continuum joint modeling techniques
Jung, J.; Brown, S.R.
1992-05-01
This paper presents the results of a numerical and experimental study in which finite element and discrete element techniques were used to analyze a layered polycarbonate plate model subjected to uniaxial compression. Also, the two analysis techniques were used to compute the response of an eight meter diameter drift in jointed-rock. The drift was subjected to in-situ and far-field induced thermal stresses. The finite element analyses used a continuum rock model to represent the jointed-rock. A comparison of the analyses showed that the finite element continuum joint model consistently predicted less joint slippage than did the discrete element analyses, although far-field displacements compared well.
THREE-DIMENSIONAL DISCRETE ORDINATES REACTOR ASSEMBLY CALCULATIONS ON GPUS
Evans, Thomas M [ORNL; Joubert, Wayne [ORNL; Hamilton, Steven P [ORNL; Johnson, Seth R [ORNL; Turner, John A [ORNL; Davidson, Gregory G [ORNL; Pandya, Tara M [ORNL
2015-01-01
In this paper we describe and demonstrate a discrete ordinates sweep algorithm on GPUs. This sweep algorithm is nested within a multilevel comunication-based decomposition based on energy. We demonstrated the effectiveness of this algorithm on detailed three-dimensional critical experiments and PWR lattice problems. For these problems we show improvement factors of 4 6 over conventional communication-based, CPU-only sweeps. These sweep kernel speedups resulted in a factor of 2 total time-to-solution improvement.
Discrete Lagrangian Systems on Graphs. Symplecto-Topological Properties
S. P. Novikov; A. S. Schwarz
2000-04-11
Discrete Lagrangian Systems on graphs are considered. Vector-valued closed differential 2-form on the space of solutions is constructed. This form takes values in the first homology group of the graph. This construction generalizes the Symplectic Wronskian for the linear self-adjoint operators on graphs found in 1997 by the first author and used for the needs of the Scattering Theory for graphs with tails
Heuristic Optimization for the Discrete Virtual Power Plant Dispatch Problem
Petersen, Mette K.; Hansen, Lars H.; Bendtsen, Jan; Edlund, Kristian; Stoustrup, Jakob
2014-10-17
We consider a virtual power plant, which is given the task of dispatching a fluctuating power supply to a portfolio of flexible consumers. The flexible consumers are modeled as discrete batch processes, and the associated optimization problem is denoted the discrete virtual power plant dispatch problem (DVPPDP). First, the nondeterministic polynomial time (NP)-completeness of the discrete virtual power plant dispatch problem is proved formally. We then proceed to develop tailored versions of the meta-heuristic algorithms hill climber and greedy randomized adaptive search procedure (GRASP). The algorithms are tuned and tested on portfolios of varying sizes. We find that all the tailored algorithms perform satisfactorily in the sense that they are able to find sub-optimal, but usable, solutions to very large problems (on the order of 105 units) at computation times on the scale of just 10 s, which is far beyond the capabilities of the optimal algorithms we have tested. In particular, GRASP sorted shows with the most promising performance, as it is able to find solutions that are both agile (sorted) and well balanced, and consistently yields the best numerical performance among the developed algorithms.
Convergence analysis of the thermal discrete dipole approximation
Edalatpour, Sheila; Trueax, Tyler; Backman, Roger; Francoeur, Mathieu
2015-01-01
The thermal discrete dipole approximation (T-DDA) is a numerical approach for modeling near-field radiative heat transfer in complex three-dimensional geometries. In this work, the convergence of the T-DDA is investigated using the exact solution for two spheres separated by a vacuum gap. The error associated with the T-DDA is reported for various size parameters, refractive indices and vacuum gap sizes. The results reveal that for a fixed number of sub-volumes, the accuracy of the T-DDA degrades as the refractive index and the sphere diameter to gap ratio increase. A converging trend is observed as the number of sub-volumes increases. The large computational requirements associated with increasing the number of sub-volumes, and the shape error induced by large sphere diameter to gap ratios, are mitigated by using a non-uniform discretization scheme. Non-uniform discretization is shown to significantly accelerate the convergence of the T-DDA, and is thus recommended for near-field thermal radiation simulation...
Space Science: Atmospheres Evolution of planets
Johnson, Robert E.
;Atmospheres / Evolution Heat Sources Compressional Energy Trapped Radioactive Material Tidal InteractionsSpace Science: Atmospheres Part- 7a Evolution of planets Out-Gassing/ Volcanoes Evolution Initial Species Solar abundance Solar wind composition? Carbonaceous chondrites? Variables Early sun
ATMOSPHERIC SCIENCE LETTERS Atmos. Sci. Let. (2012)
Gerber, Edwin
2012-01-01
ATMOSPHERIC SCIENCE LETTERS Atmos. Sci. Let. (2012) Published online in Wiley Online Library using National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP) concentrations and sea- surface temperatures (SSTs). These integrations enable the relative role of ozone
Equilibration of an atmosphere by geostrophic turbulence
Jansen, Malte F. (Malte Friedrich)
2013-01-01
A major question for climate studies is to quantify the role of turbulent eddy fluxes in maintaining the observed atmospheric mean state. It has been argued that eddy fluxes keep the mid-latitude atmosphere in a state that ...
Land and Atmospheric Science GRAD STUDENT HANDBOOK
Minnesota, University of
Land and Atmospheric Science GRAD STUDENT HANDBOOK 20142015 WELCOME Welcome to the Graduate Program in Land and Atmospheric Science at the University of Minnesota. It is a sciencebased interdisciplinary program focused on the fundamentals of Earth system processes related
Atmospheric Chemistry and Air Pollution
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gaffney, Jeffrey S.; Marley, Nancy A.
2003-01-01
Atmospheric chemistry is an important discipline for understanding air pollution and its impacts. This mini-review gives a brief history of air pollution and presents an overview of some of the basic photochemistry involved in the production of ozone and other oxidants in the atmosphere. Urban air quality issues are reviewed with a specific focus on ozone and other oxidants, primary and secondary aerosols, alternative fuels, and the potential for chlorine releases to amplify oxidant chemistry in industrial areas. Regional air pollution issues such as acid rain, long-range transport of aerosols and visibility loss, and the connections of aerosols to ozonemore »and peroxyacetyl nitrate chemistry are examined. Finally, the potential impacts of air pollutants on the global-scale radiative balances of gases and aerosols are discussed briefly.« less
Radar range measurements in the atmosphere.
Doerry, Armin Walter
2013-02-01
The earth's atmosphere affects the velocity of propagation of microwave signals. This imparts a range error to radar range measurements that assume the typical simplistic model for propagation velocity. This range error is a function of atmospheric constituents, such as water vapor, as well as the geometry of the radar data collection, notably altitude and range. Models are presented for calculating atmospheric effects on radar range measurements, and compared against more elaborate atmospheric models.
Earth and Atmospheric Sciences | More Science | ORNL
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Earth and Atmospheric Sciences Nuclear Forensics Climate & Environment Sensors and Measurements Chemical & Engineering Materials Computational Earth Science Systems Modeling...
Atmospheric-pressure plasma jet
Selwyn, Gary S. (Los Alamos, NM)
1999-01-01
Atmospheric-pressure plasma jet. A .gamma.-mode, resonant-cavity plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 300 W, and shows distinct non-thermal characteristics. In the simplest design, two concentric cylindrical electrodes are employed to generate a plasma in the annular region therebetween. A "jet" of long-lived metastable and reactive species that are capable of rapidly cleaning or etching metals and other materials is generated which extends up to 8 in. beyond the open end of the electrodes. Films and coatings may also be removed by these species. Arcing is prevented in the apparatus by using gas mixtures containing He, which limits ionization, by using high flow velocities, and by properly shaping the rf-powered electrode. Because of the atmospheric pressure operation, no ions survive for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike low-pressure plasma sources and conventional plasma processing methods.
A Recognized Leader in Marine & Atmospheric
Miami, University of
D/Masters Applied Marine Physics Marine & Atmospheric Chemistry Marine Affairs & Policy (Masters Only) MarineA Recognized Leader in Marine & Atmospheric Studies Our graduate program has over 250 students University of MiaMi rosenstiel school of Marine & atMospheric science #12;Miami Ranks #5: fDi Magazine's Top
Atmospheric evolution on Venus Bruce Fegley, Jr.
1 Atmospheric evolution on Venus Bruce Fegley, Jr. Planetary Chemistry Laboratory Department by Hunten et al. (1983), of Magellan results by Bougher et al. (1997), and atmospheric chemistry on Venus and Ancient Environments Edited by Vivien Gornitz January 2004 #12;2 ATMOSPHERIC EVOLUTION ON VENUS Overview
Atmospheric Lifetime of Fossil Fuel Carbon Dioxide
Atmospheric Lifetime of Fossil Fuel Carbon Dioxide David Archer,1 Michael Eby,2 Victor Brovkin,3 released from combustion of fossil fuels equilibrates among the various carbon reservoirs of the atmosphere literature on the atmospheric lifetime of fossil fuel CO2 and its impact on climate, and we present initial
Proof of the Atmospheric Greenhouse Effect
Smith, Arthur P
2008-01-01
A recently advanced argument against the atmospheric greenhouse effect is refuted. A planet without an infrared absorbing atmosphere is mathematically constrained to have an average temperature less than or equal to the effective radiating temperature. Observed parameters for Earth prove that without infrared absorption by the atmosphere, the average temperature of Earth's surface would be at least 33 K lower than what is observed.
Atmospheric composition change - global and regional air quality
2009-01-01
in urban air. Atmospheric Chemistry and Physics 5, 2881–deep convective system. Atmospheric Chemistry and Physics 4,processes in atmospheric chemistry. Chemical Society Review
Coupling of nitrous oxide and methane by global atmospheric chemistry
Prather, MJ; Hsu, J
2010-01-01
supported by NSF’s Atmospheric Chemistry program (grant ATM-Methane by Global Atmospheric Chemistry Michael J. Prathergas, through atmospheric chemistry that en- hances the
Formation mechanisms and quantification of organic nitrates in atmospheric aerosol
Rollins, Andrew Waite
2010-01-01
and J. Viidanoja, Atmospheric chemistry of c 3 -c 6organic nitrates, Atmospheric Chemistry and Physics, 9 (4),organic aerosol yields, Atmospheric Chemistry and Physics
1997 Atmospheric Chemistry Colloquium for Emerging Senior Scientists
Paul H. Wine
1998-11-23
DOE's Atmospheric Chemistry Program is providing partial funding for the Atmospheric Chemistry Colloquium for Emerging Senior Scientists (ACCESS) and FY 1997 Gordon Research Conference in Atmospheric Chemistry
Grossmann, Ignacio E.
: · ambient temperature · wind speed · solar and atmospheric radiation · some basic characteristics. The mode incorporates: · ambient temperature · wind speed · solar and atmospheric radiation · some basic at building a simulation-tool that will be used to determine the impact of supply chain conditions on product
Lowenstein, Andrew; Miller, Jeffrey; Gruendeman, Peter; DaSilva, Michael
2005-02-01
An air conditioner comprises a plurality of plates arranged in a successively stacked configuration with portions thereof having a spaced apart arrangement, and defining between successive adjacent pairs of plates at the spaced apart portions a first and second series of discrete alternating passages wherein a first air stream is passed through the first series of passages and a second air stream is passed through the second series of passages; and said stacked configuration of plates forming integrally therewith a liquid delivery means for delivering from a source a sufficient quantity of a liquid to the inside surfaces of the first series of fluid passages in a manner which provides a continuous flow of the liquid from a first end to a second end of the plurality of plates while in contact with the first air stream.
Schellart, P; Buitink, S; Corstanje, A; Enriquez, J E; Falcke, H; Hörandel, J R; Nelles, A; Rachen, J P; Rossetto, L; Scholten, O; ter Veen, S; Thoudam, S; Ebert, U; Koehn, C; Rutjes, C; Alexov, A; Anderson, J M; Avruch, I M; Bentum, M J; Bernardi, G; Best, P; Bonafede, A; Breitling, F; Broderick, J W; Brüggen, M; Butcher, H R; Ciardi, B; de Geus, E; de Vos, M; Duscha, S; Eislöffel, J; Fallows, R A; Frieswijk, W; Garrett, M A; Grießmeier, J; Gunst, A W; Heald, G; Hessels, J W T; Hoeft, M; Holties, H A; Juette, E; Kondratiev, V I; Kuniyoshi, M; Kuper, G; Mann, G; McFadden, R; McKay-Bukowski, D; McKean, J P; Mevius, M; Moldon, J; Norden, M J; Orru, E; Paas, H; Pandey-Pommier, M; Pizzo, R; Polatidis, A G; Reich, W; Röttgering, H; Scaife, A M M; Schwarz, D J; Serylak, M; Smirnov, O; Steinmetz, M; Swinbank, J; Tagger, M; Tasse, C; Toribio, M C; van Weeren, R J; Vermeulen, R; Vocks, C; Wise, M W; Wucknitz, O; Zarka, P
2015-01-01
We present measurements of radio emission from cosmic ray air showers that took place during thunderstorms. The intensity and polarization patterns of these air showers are radically different from those measured during fair-weather conditions. With the use of a simple two-layer model for the atmospheric electric field, these patterns can be well reproduced by state-of-the-art simulation codes. This in turn provides a novel way to study atmospheric electric fields.
Cobos, Douglas Russell
1999-01-01
Carbon dioxide exchange rate (CER) is an indicator of an ecosystem's response to changing environmental conditions. Long-term measurements of CO? exchange between coastal wetlands and the atmosphere will improve our understanding of daily...
Pulsed atmospheric fluidized bed combustion
Not Available
1993-01-01
The Design and Engineering of most components in the Pulsed Atmospheric Fluidized Bed System was completed prior to September 1992. The components remaining to be designed at that time were: Aerovalves for the Pulse Combustor; Gas and coal injectors for the Pulse Combustor; Lines for PC tailpipes; Air plenum and inlet silencer; Refractory lined hot gas duct connecting outlet hot cyclone to boiler; Structure and platforms, and ladders around PAFBC vessel access and major equipment. Design work is currently in progress on all of the above components. Items 1, 2, 3 and 4 are 50% completed, and items 5 6 are 75% complete.
RHEOLOGICAL STUDY OF AN HYDRATE SLURRY FOR AIR CONDITIONNING APPLICATION
Boyer, Edmond
Saint-Etienne France ABSTRACT Under atmospheric pressure condition and temperatures between 0°C and +12 behaviour. The experimental device is made up of a brushed surface heat exchanger in which the hydrates flow rates and pressure drops measurements. We obtain flow curves of hydrates slurries depending
Mechanical Performance Extreme Conditions
Mechanical Performance Extreme Conditions METALS This project provides property data, metrology information using the image correlation technique. With this instrument, high strain rate mechanical testing
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Testbed Results Current Testbed Research Proposal Process Terms and Conditions Dark Fiber Testbed Federated Testbed Circuits Test Circuit Service Performance (perfSONAR)...
Natalie Marie Mahowald Department of Earth and Atmospheric Sciences
Mahowald, Natalie
in the Community Atmosphere Model: development of framework and impact on radiative forcing, Atmospheric Chemistry, Atmospheric Chemistry and 1 1 Natalie Marie Mahowald Department of Earth and Atmospheric Sciences Professor Director
Quantum mechanics as a consequence of discrete interactions
Gabriele Carcassi
2008-01-05
Quantum mechanics is usually presented starting from a series of postulates about the mathematical framework. In this work we show that those same postulates can be derived by assuming that measurements are discrete interactions: that is, that we measure at specific moments in time (as opposed to a continuous measurement that spans a long time interval) and that the system is in general affected by our measurement. We believe that this way of presenting quantum mechanics would make it easier to understand by laying out a more cohesive view of the theory and making it resonate more with our physics intuition.
Leptons and Quarks from a Discrete Flavor Symmetry
Y. H. Ahn
2013-03-20
We propose a new model of leptons and quarks based on the discrete flavor symmetry $T'$, the double covering of $A_4$, in which the hierarchies of charged fermion masses and the mildness of neutrino masses are responsible for Higgs scalars. After spontaneous breaking of flavor symmetry, with the constraint of renormalizability in the Lagrangian, the leptons have $m_{e}=0$ and the quarks have the Cabibbo-Kobayashi-Maskawa (CKM) mixing angles $\\theta^{q}_{12}=13^{\\circ}, \\theta^{q}_{23}=0^{\\circ}$ and $\\theta^{q}_{13}=0^{\\circ}$. Thus, certain effective dimension-5 operators are introduced, which induce $m_{e}\
Signatures of discrete symmetries in the scalar sector
Lavoura, L. (Department of Physics, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213 (United States))
1994-12-01
I discuss methods to identify the presence of discrete symmetries in the two-Higgs-doublet model by observing the masses and the cubic and quartic interactions of the scalars. The symmetries considered are a [ital Z][sub 2] symmetry under which [phi][sub 2][r arrow][minus][phi][sub 2], and a [ital CP] symmetry which enforces real coupling constants in the Higgs potential. Those symmetries are spontaneously broken, and the [ital Z][sub 2] symmetry may also be softly broken. I identify the signatures in the interactions of the scalars that these symmetries leave after their breaking.
Hu, Jian Zhi (Richland, WA); Sears, Jr., Jesse A. (Kennewick, WA); Hoyt, David W. (Richland, WA); Wind, Robert A. (Kennewick, WA)
2009-05-19
Described are a "Discrete Magic Angle Turning" (DMAT) system, devices, and processes that combine advantages of both magic angle turning (MAT) and magic angle hopping (MAH) suitable, e.g., for in situ magnetic resonance spectroscopy and/or imaging. In an exemplary system, device, and process, samples are rotated in a clockwise direction followed by an anticlockwise direction of exactly the same amount. Rotation proceeds through an angle that is typically greater than about 240 degrees but less than or equal to about 360 degrees at constant speed for a time applicable to the evolution dimension. Back and forth rotation can be synchronized and repeated with a special radio frequency (RF) pulse sequence to produce an isotropic-anisotropic shift 2D correlation spectrum. The design permits tubes to be inserted into the sample container without introducing plumbing interferences, further allowing control over such conditions as temperature, pressure, flow conditions, and feed compositions, thus permitting true in-situ investigations to be carried out.
Regional Ecosystem-Atmosphere CO2 Exchange Via Atmospheric Budgets
Davis, K.J.; Richardson, S.J.; Miles, N.L.
2007-03-07
Inversions of atmospheric CO2 mixing ratio measurements to determine CO2 sources and sinks are typically limited to coarse spatial and temporal resolution. This limits our ability to evaluate efforts to upscale chamber- and stand-level CO2 flux measurements to regional scales, where coherent climate and ecosystem mechanisms govern the carbon cycle. As a step towards the goal of implementing atmospheric budget or inversion methodology on a regional scale, a network of five relatively inexpensive CO2 mixing ratio measurement systems was deployed on towers in northern Wisconsin. Four systems were distributed on a circle of roughly 150-km radius, surrounding one centrally located system at the WLEF tower near Park Falls, WI. All measurements were taken at a height of 76 m AGL. The systems used single-cell infrared CO2 analyzers (Licor, model LI-820) rather than the siginificantly more costly two-cell models, and were calibrated every two hours using four samples known to within ± 0.2 ppm CO2. Tests prior to deployment in which the systems sampled the same air indicate the precision of the systems to be better than ± 0.3 ppm and the accuracy, based on the difference between the daily mean of one system and a co-located NOAA-ESRL system, is consistently better than ± 0.3 ppm. We demonstrate the utility of the network in two ways. We interpret regional CO2 differences using a Lagrangian parcel approach. The difference in the CO2 mixing ratios across the network is at least 2?3 ppm, which is large compared to the accuracy and precision of the systems. Fluxes estimated assuming Lagrangian parcel transport are of the same sign and magnitude as eddy-covariance flux measurements at the centrally-located WLEF tower. These results indicate that the network will be useful in a full inversion model. Second, we present a case study involving a frontal passage through the region. The progression of a front across the network is evident; changes as large as four ppm in one minute are captured. Influence functions, derived using a Lagrangian Particle Dispersion model driven by the CSU Regional Atmospheric Modeling System and nudged to NCEP reanalysis meteorological fields, are used to determine source regions for the towers. The influence functions are combined with satellite vegetation observations to interpret the observed trends in CO2 concentration. Full inversions will combine these elements in a more formal analytic framework.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Huang, Lei; Zuo, Chao; Idir, Mourad; Qu, Weijuan; Asundi, Anand
2015-04-21
A novel transport-of-intensity equation (TIE) based phase retrieval method is proposed with putting an arbitrarily-shaped aperture into the optical wavefield. In this arbitrarily-shaped aperture, the TIE can be solved under non-uniform illuminations and even non-homogeneous boundary conditions by iterative discrete cosine transforms with a phase compensation mechanism. Simulation with arbitrary phase, arbitrary aperture shape, and non-uniform intensity distribution verifies the effective compensation and high accuracy of the proposed method. Experiment is also carried out to check the feasibility of the proposed method in real measurement. Comparing to the existing methods, the proposed method is applicable for any types of phasemore »distribution under non-uniform illumination and non-homogeneous boundary conditions within an arbitrarily-shaped aperture, which enables the technique of TIE with hard aperture become a more flexible phase retrieval tool in practical measurements.« less
THE LOS ALAMOS NATIONAL LABORATORY ATMOSPHERIC TRANSPORT AND DIFFUSION MODELS
M. WILLIAMS
1999-08-01
The LANL atmospheric transport and diffusion models are composed of two state-of-the-art computer codes. The first is an atmospheric wind model called HOThlAC, Higher Order Turbulence Model for Atmospheric circulations. HOTMAC generates wind and turbulence fields by solving a set of atmospheric dynamic equations. The second is an atmospheric diffusion model called RAPTAD, Random Particle Transport And Diffusion. RAPTAD uses the wind and turbulence output from HOTMAC to compute particle trajectories and concentration at any location downwind from a source. Both of these models, originally developed as research codes on supercomputers, have been modified to run on microcomputers. Because the capability of microcomputers is advancing so rapidly, the expectation is that they will eventually become as good as today's supercomputers. Now both models are run on desktop or deskside computers, such as an IBM PC/AT with an Opus Pm 350-32 bit coprocessor board and a SUN workstation. Codes have also been modified so that high level graphics, NCAR Graphics, of the output from both models are displayed on the desktop computer monitors and plotted on a laser printer. Two programs, HOTPLT and RAPLOT, produce wind vector plots of the output from HOTMAC and particle trajectory plots of the output from RAPTAD, respectively. A third CONPLT provides concentration contour plots. Section II describes step-by-step operational procedures, specifically for a SUN-4 desk side computer, on how to run main programs HOTMAC and RAPTAD, and graphics programs to display the results. Governing equations, boundary conditions and initial values of HOTMAC and RAPTAD are discussed in Section III. Finite-difference representations of the governing equations, numerical solution procedures, and a grid system are given in Section IV.
Discrete-element modeling of particulate aerosol flows
Marshall, J.S. [School of Engineering, University of Vermont, 33 Colchecter Avenue, Burlington, Vermont 05405 (United States)], E-mail: jeffm@cems.uvm.edu
2009-03-20
A multiple-time step computational approach is presented for efficient discrete-element modeling of aerosol flows containing adhesive solid particles. Adhesive aerosol particulates are found in numerous dust and smoke contamination problems, including smoke particle transport in the lungs, particle clogging of heat exchangers in construction vehicles, industrial nanoparticle transport and filtration systems, and dust fouling of electronic systems and MEMS components. Dust fouling of equipment is of particular concern for potential human occupation on dusty planets, such as Mars. The discrete-element method presented in this paper can be used for prediction of aggregate structure and breakup, for prediction of the effect of aggregate formation on the bulk fluid flow, and for prediction of the effects of small-scale flow features (e.g., due to surface roughness or MEMS patterning) on the aggregate formation. After presentation of the overall computational structure, the forces and torques acting on the particles resulting from fluid motion, particle-particle collision, and adhesion under van der Waals forces are reviewed. The effect of various parameters of normal collision and adhesion of two particles are examined in detail. The method is then used to examine aggregate formation and particle clogging in pipe and channel flow.
Discrete transforms and orthogonal polynomials of (anti)symmetric multivariate cosine functions
Ji?í Hrivnák; Lenka Motlochová
2014-11-27
The discrete cosine transforms of types V--VIII are generalized to the antisymmetric and symmetric multivariate discrete cosine transforms. Four families of discretely and continuously orthogonal Chebyshev-like polynomials corresponding to the antisymmetric and symmetric generalizations of cosine functions are introduced. Each family forms an orthogonal basis of the space of all polynomials with respect to some weighted integral. Cubature formulas, which correspond to these families of polynomials and which stem from the developed discrete cosine transforms, are derived. Examples of three-dimensional interpolation formulas and three-dimensional explicit forms of the polynomials are presented.
Microscale and mesoscale discrete models for dynamic fracture of structures built of brittle are derived either at microscale with random distribution of material properties or at a mesoscale
Conditioning analysis of incomplete Cholesky factorizations with orthogonal dropping
Napov, Artem
2012-03-16
The analysis of preconditioners based on incomplete Cholesky factorization in which the neglected (dropped) components are orthogonal to the approximations being kept is presented. General estimate for the condition number of the preconditioned system is given which only depends on the accuracy of individual approximations. The estimate is further improved if, for instance, only the newly computed rows of the factor are modified during each approximation step. In this latter case it is further shown to be sharp. The analysis is illustrated with some existing factorizations in the context of discretized elliptic partial differential equations.
Pulsed atmospheric fluidized bed combustion
Not Available
1992-10-01
The design of the Pulsed Atmospheric Fluidized Bed Combustor (PAFBC) as described in the Quarterly Report for the period April--June, 1992 was reviewed and minor modifications were included. The most important change made was in the coal/limestone preparation and feed system. Instead of procuring pre-sized coal for testing of the PAFBC, it was decided that the installation of a milling system would permit greater flexibility in the testing with respect to size distributions and combustion characteristics in the pulse combustor and the fluid bed. Particle size separation for pulse combustor and fluid bed will be performed by an air classifier. The modified process flow diagram for the coal/limestone handling system is presented in Figure 1. The modified process flow diagrams of the fluidized bed/steam cycle and ash handling systems are presented in Figures 2 and 3, respectively.
Mesoscale coupled ocean-atmosphere interaction
Seo, Hyodae
2007-01-01
mesoscale oceanic features are current coarse resolutionmesoscale r current variability associated with oceanic ringthe TIW- currents. These mesoscale oceanic and atmospheric
Mesoscale Coupled Ocean-Atmosphere Interaction
Seo, Hyodae
2007-01-01
mesoscale oceanic features are current coarse resolutionmesoscale r current variability associated with oceanic ringthe TIW- currents. These mesoscale oceanic and atmospheric
Physics Potential of Future Atmospheric Neutrino Searches
Thomas Schwetz
2008-12-12
The potential of future high statistics atmospheric neutrino experiments is considered, having in mind currently discussed huge detectors of various technologies (water Cerekov, magnetized iron, liquid Argon). I focus on the possibility to use atmospheric data to determine the octant of $\\theta_{23}$ and the neutrino mass hierarchy. The sensitivity to the $\\theta_{23}$-octant of atmospheric neutrinos is competitive (or even superior) to long-baseline experiments. I discuss the ideal properties of a fictitious atmospheric neutrino detector to determine the neutrino mass hierarchy.
4, 497545, 2011 atmosphere-wildland
Mandel, Jan
by the coupling of a mesoscale weather 498 #12;GMDD 4, 497545, 2011 Coupled atmosphere-wildland model WRF-Fire 3
Impacts of Atmospheric Anthropogenic Nitrogen on the
Ward, Bess
discharges from wastewater treatment, atmospheric deposition, and so forth, resulting in increasing), including oxidized and reduced inorganic and organic forms. The availability of Nr limits primary pro
Composition and Reactions of Atmospheric Aerosol Particles
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on high-resolution scanning transmission x-ray images obtained at the ALS have revealed chemical reactions on and in atmospheric aerosol particles that caused particle growth...
Atmospheric chemistry of an Antarctic volcanic plume
2010-01-01
ET AL. : EREBUS PLUME CHEMISTRY Horrocks, L. A. , C.et al. (2010), Atmospheric chemistry results from the ANTCI2007), Reactive halogen chemistry in volca- nic plumes, J.
Nanoindentation Under Dynamic Conditions
Wheeler, Jeffrey M
2009-05-22
and in analysis of the resulting data. Recent development has enabled investigation of materials under several dynamic conditions. The palladium-hydrogen system has a large miscibility gap, where the palladium lattice rapidly expands to form a hydrogen-rich ?...
Fish Passage though Hydropower Turbines: Simulating Blade Strike using the Discrete Element Method
Richmond, Marshall C.; Romero Gomez, Pedro DJ
2014-12-08
mong the hazardous hydraulic conditions affecting anadromous and resident fish during their passage though turbine flows, two are believed to cause considerable injury and mortality: collision on moving blades and decompression. Several methods are currently available to evaluate these stressors in installed turbines, i.e. using live fish or autonomous sensor devices, and in reduced-scale physical models, i.e. registering collisions from plastic beads. However, a priori estimates with computational modeling approaches applied early in the process of turbine design can facilitate the development of fish-friendly turbines. In the present study, we evaluated the frequency of blade strike and nadir pressure environment by modeling potential fish trajectories with the Discrete Element Method (DEM) applied to fish-like composite particles. In the DEM approach, particles are subjected to realistic hydraulic conditions simulated with computational fluid dynamics (CFD), and particle-structure interactions—representing fish collisions with turbine blades—are explicitly recorded and accounted for in the calculation of particle trajectories. We conducted transient CFD simulations by setting the runner in motion and allowing for better turbulence resolution, a modeling improvement over the conventional practice of simulating the system in steady state which was also done here. While both schemes yielded comparable bulk hydraulic performance, transient conditions exhibited a visual improvement in describing flow variability. We released streamtraces (steady flow solution) and DEM particles (transient solution) at the same location from where sensor fish (SF) have been released in field studies of the modeled turbine unit. The streamtrace-based results showed a better agreement with SF data than the DEM-based nadir pressures did because the former accounted for the turbulent dispersion at the intake but the latter did not. However, the DEM-based strike frequency is more representative of blade-strike probability than the steady solution is, mainly because DEM particles accounted for the full fish length, thus resolving (instead of modeling) the collision event.
Sandia Energy - Extreme Conditions Modeling
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Extreme Conditions Modeling Home Stationary Power Energy Conversion Efficiency Water Power Technology Development Extreme Conditions Modeling Extreme Conditions ModelingAshley...
Conditional data watchpoint management
Burdick, Dean Joseph (Austin, TX); Vaidyanathan, Basu (Austin, TX)
2010-08-24
A method, system and computer program product for managing a conditional data watchpoint in a set of instructions being traced is shown in accordance with illustrative embodiments. In one particular embodiment, the method comprises initializing a conditional data watchpoint and determining the watchpoint has been encountered. Upon that determination, examining a current instruction context associated with the encountered watchpoint prior to completion of the current instruction execution, further determining a first action responsive to a positive context examination; otherwise, determining a second action.
Zhuang, Qianlai
Soil consumption of atmospheric methane plays an important secondary role in regulating the atmospheric CH4 budget, next to the dominant loss mechanism involving reaction with the hydroxyl radical (OH). Here we used a ...
NDE to Manage Atmospheric SCC in Canisters for Dry Storage of Spent Fuel: An Assessment
Meyer, Ryan M.; Pardini, Allan F.; Cuta, Judith M.; Adkins, Harold E.; Casella, Andrew M.; Qiao, Hong; Larche, Michael R.; Diaz, Aaron A.; Doctor, Steven R.
2013-09-01
This report documents efforts to assess representative horizontal (Transuclear NUHOMS®) and vertical (Holtec HI-STORM) storage systems for the implementation of non-destructive examination (NDE) methods or techniques to manage atmospheric stress corrosion cracking (SCC) in canisters for dry storage of used nuclear fuel. The assessment is conducted by assessing accessibility and deployment, environmental compatibility, and applicability of NDE methods. A recommendation of this assessment is to focus on bulk ultrasonic and eddy current techniques for direct canister monitoring of atmospheric SCC. This assessment also highlights canister regions that may be most vulnerable to atmospheric SCC to guide the use of bulk ultrasonic and eddy current examinations. An assessment of accessibility also identifies canister regions that are easiest and more difficult to access through the ventilation paths of the concrete shielding modules. A conceivable sampling strategy for canister inspections is to sample only the easiest to access portions of vulnerable regions. There are aspects to performing an NDE inspection of dry canister storage system (DCSS) canisters for atmospheric SCC that have not been addressed in previous performance studies. These aspects provide the basis for recommendations of future efforts to determine the capability and performance of eddy current and bulk ultrasonic examinations for atmospheric SCC in DCSS canisters. Finally, other important areas of investigation are identified including the development of instrumented surveillance specimens to identify when conditions are conducive for atmospheric SCC, characterization of atmospheric SCC morphology, and an assessment of air flow patterns over canister surfaces and their influence on chloride deposition.
3D imaging of semiconductor components by discrete laminography
Batenburg, K. J.; Palenstijn, W. J.; Sijbers, J.
2014-06-19
X-ray laminography is a powerful technique for quality control of semiconductor components. Despite the advantages of nondestructive 3D imaging over 2D techniques based on sectioning, the acquisition time is still a major obstacle for practical use of the technique. In this paper, we consider the application of Discrete Tomography to laminography data, which can potentially reduce the scanning time while still maintaining a high reconstruction quality. By incorporating prior knowledge in the reconstruction algorithm about the materials present in the scanned object, far more accurate reconstructions can be obtained from the same measured data compared to classical reconstruction methods. We present a series of simulation experiments that illustrate the potential of the approach.
Origin of coherent structures in a discrete chaotic medium
Rabinovich, M.I.; Torres, J.J.; Varona, P.; Huerta, R.; Varona, P.; Huerta, R.; Weidman, P.
1999-08-01
Using as an example a large lattice of locally interacting Hindmarsh-Rose chaotic neurons, we disclose the origin of ordered structures in a discrete nonequilibrium medium with fast and slow chaotic oscillations. The origin of the ordering mechanism is related to the appearance of a periodic average dynamics in the group of chaotic neurons whose individual slow activity is significantly synchronized by the group mean field. Introducing the concept of a {open_quotes}coarse grain{close_quotes} as a cluster of neuron elements with periodic averaged behavior allows consideration of the dynamics of a medium composed of these clusters. A study of this medium reveals spatially ordered patterns in the periodic and slow dynamics of the coarse grains that are controlled by the average intensity of the fast chaotic pulsation. {copyright} {ital 1999} {ital The American Physical Society}
Semiclassical approach to discrete symmetries in quantum chaos
Joyner, Chris; Sieber, Martin
2012-01-01
We use semiclassical methods to evaluate the spectral two-point correlation function of quantum chaotic systems with discrete geometrical symmetries. The energy spectra of these systems can be divided into subspectra that are associated to irreducible representations of the corresponding symmetry group. We show that for (spinless) time reversal invariant systems the statistics inside these subspectra depend on the type of irreducible representation. For real representations the spectral statistics agree with those of the Gaussian Orthogonal Ensemble (GOE) of Random Matrix Theory (RMT), whereas complex representations correspond to the Gaussian Unitary Ensemble (GUE). For systems without time reversal invariance all subspectra show GUE statistics. There are no correlations between non-degenerate subspectra. Our techniques generalize recent developments in the semiclassical approach to quantum chaos allowing one to obtain full agreement with the two-point correlation function predicted by RMT, including oscilla...
Semiclassical approach to discrete symmetries in quantum chaos
Chris Joyner; Sebastian Müller; Martin Sieber
2012-02-22
We use semiclassical methods to evaluate the spectral two-point correlation function of quantum chaotic systems with discrete geometrical symmetries. The energy spectra of these systems can be divided into subspectra that are associated to irreducible representations of the corresponding symmetry group. We show that for (spinless) time reversal invariant systems the statistics inside these subspectra depend on the type of irreducible representation. For real representations the spectral statistics agree with those of the Gaussian Orthogonal Ensemble (GOE) of Random Matrix Theory (RMT), whereas complex representations correspond to the Gaussian Unitary Ensemble (GUE). For systems without time reversal invariance all subspectra show GUE statistics. There are no correlations between non-degenerate subspectra. Our techniques generalize recent developments in the semiclassical approach to quantum chaos allowing one to obtain full agreement with the two-point correlation function predicted by RMT, including oscillatory contributions.
A three-level BDDC algorithm for mortar discretizations
Kim, Hyea Hyun; Tu, Xuemin
2009-03-05
Society for Industrial and Applied Mathematics Vol. 47, No. 2, pp. 1576–1600 A THREE-LEVEL BDDC ALGORITHM FOR MORTAR DISCRETIZATIONS? HYEA HYUN KIM† AND XUEMIN TU‡ Abstract. In this paper, a three-level balancing domain decomposition by constraints (BDDC...- search, U.S. Department of Energy under contract DE-AC02-05CH11231. 1576 D ow nl oa de d 09 /2 9/ 14 to 1 29 .2 37 .4 6. 10 0. R ed ist rib ut io n su bje ct to SIA M lic en se or co py rig ht; se e h ttp ://w ww .si am .or g/j ou rna ls/ ojs a...
Continuum discretized BCS approach for weakly bound nuclei
J. A. Lay; C. E. Alonso; L. Fortunato; A. Vitturi
2015-10-12
The Bardeen-Cooper-Schrieffer (BCS) formalism is extended by including the single-particle continuum, thus enabling the analysis of an isotopic chain from stability up to the drip line. We propose a continuum discretized generalized BCS based on single-particle pseudostates (PS). These PS are generated from the diagonalization of the single-particle Hamiltonian within a Transformed Harmonic Oscillator (THO) basis. The consistency of the results versus the size of the basis is studied. The method is applied to neutron rich Oxygen and Carbon isotopes and compared with similar previous works and available experimental data. We make use of the flexibility of the proposed model in order to study the evolution of the occupation of the low-energy continuum when the system becomes weakly bound. We find a larger influence of the non-resonant continuum as long as the Fermi level approaches zero.
Breaking discrete symmetries in the effective field theory of inflation
Dario Cannone; Jinn-Ouk Gong; Gianmassimo Tasinato
2015-05-29
We study the phenomenon of discrete symmetry breaking during the inflationary epoch, using a model-independent approach based on the effective field theory of inflation. We work in a context where both time reparameterization symmetry and spatial diffeomorphism invariance can be broken during inflation. We determine the leading derivative operators in the quadratic action for fluctuations that break parity and time-reversal. Within suitable approximations, we study their consequences for the dynamics of linearized fluctuations. Both in the scalar and tensor sectors, we show that such operators can lead to new direction-dependent phases for the modes involved. They do not affect the power spectra, but can have consequences for higher correlation functions. Moreover, a small quadrupole contribution to the sound speed can be generated.
74 MHz Discrete HII Absorption Regions Towards The Inner Galaxy
Michael E. Nord; P. A. Henning; R. J. Rand; T. Joseph W. Lazio; Namir E. Kassim
2006-03-02
At low radio frequencies ( 1) and can be observed as discrete absorption regions against the Galactic nonthermal background emission created by Galactic cosmic ray electrons spiraling around magnetic fields. In this work we present 74 MHz observations in the region 26>l>-15, -5
Quantum Discrete Fourier Transform with Classical Output for Signal Processing
Chao-Yang Pang; Ben-Qiong Hu
2007-06-17
Discrete Fourier transform (DFT) is the base of modern signal or information processing. 1-Dimensional fast Fourier transform (1D FFT) and 2D FFT have time complexity O(NlogN) and O(N^2logN) respectively. Quantum 1D and 2D DFT algorithms with classical output (1D QDFT and 2D QDFT) are presented in this paper. And quantum algorithm for convolution estimation is also presented in this paper. Compared with FFT, QDFT has two advantages at least. One of advantages is that 1D and 2D QDFT has time complexity O(sqrt(N)) and O(N) respectively. The other advantage is that QDFT can process very long signal sequence at a time. QDFT and quantum convolution demonstrate that quantum signal processing with classical output is possible.
Multipole-preserving quadratures for discretization of functions
Genovese, Luigi
2015-01-01
Discretizing an analytic function on a uniform real-space grid is often done via a straightforward collocation method. This is ubiquitous in all areas of computational physics and quantum chemistry. An example in Density Functional Theory is given by the local external potential describing the interaction between ions and electrons. Also notable examples are given by the analytic functions defining compensation charges for range-separated electrostatic treatments. The accuracy of the collocation method used is therefore very important for the reliability of subsequent treatments like self-consistent field solutions of the electronic structure problems. When the real-space grid is too coarse, the collocation method introduces numerical artifacts typical of real-space treatments, like the so-called egg-box error, that may spoil the numerical stability of the description. We present in this paper a new quadrature scheme that is able to exactly preserve the multipoles of a given analytic function for a wide range...
ATMOSPHERIC SCIENCE LETTERS Atmos. Sci. Let. (2013)
Lee, Sukyoung
2013-01-01
ATMOSPHERIC SCIENCE LETTERS Atmos. Sci. Let. (2013) Published online in Wiley Online Library Sciences, Seoul National University, Seoul, South Korea *Correspondence to: C. Yoo, Center for Atmosphere). A number of studies have shown that the MJO plays an important role in modulating the extratropical cir
Stellar Atmospheres, Ht 2007 Problem Set 1
Korn, Andreas
Stellar Atmospheres, Ht 2007 Problem Set 1 Due date: Monday, 24 September 2007 at 10.15 1. LTE of how temperature is defined. (b) Where in the solar atmosphere would you expect the strongest for the photosphere? (c) How does the relation between matter and radiation differ between LTE and NLTE? What must
Results from the Phoenix Atmospheric Structure Experiment
Withers, Paul
Results from the Phoenix Atmospheric Structure Experiment Paul Withers1 and David Catling2 (1 and atmospheric structure reconstruction for Phoenix Â· Highlight selected aspects of Phoenix reconstruction reconstruction for Phoenix Â· Highlight selected aspects of Phoenix reconstruction that offer lessons for future
Geochemistry of Surface-Atmosphere Interactions on
Withers, Paul
, T, and atmospheric composition Ą ...Kinetics Ą What are the major minerals? Ą What is the oxidation of terrestrial alkaline igneous rocks #12;Oxidation State of the Surface Ą 2CO + O2 = 2CO2 controls O2 Ą Lack. Ą S in lower atmosphere is kinetically controlled Ą CaCO3 + SO2 = CaSO4 + CO removes SO2 , deposits CaSO4 Ą Fe
Interaction of discrete breathers with electrons in nonlinear lattices S. Flach* and K. Kladko
Flach, Sergej
Interaction of discrete breathers with electrons in nonlinear lattices S. Flach* and K. Kladko Max 1995 We study the effects of electron-lattice interaction in the presence of discrete breathers. The lattice is treated classically. We consider two different situations: i the scattering of an electron
Discrete Applied Mathematics Special Issue: Mathematics based Cryptography and Future Security
Discrete Applied Mathematics Special Issue: Mathematics based Cryptography and Future Security for such systems is cryptography. The mathematical techniques of cryptography can be related to such aspects mathematics. Topics to be considered for the special issue are: - Discrete and combinatorial mathematics based
Antsaklis, Panos
Switching Stabilization and l2 Gain Performance Controller Synthesis for Discrete-Time Switched Linear Systems Hai Lin and Panos J. Antsaklis Abstract-- In this paper, the switching controller synthesis problem for a class of discrete-time switched linear systems is considered. In particular, a state
Computational Issues in Intelligent Control: Discrete-Event and Hybrid Systems
Koutsoukos, Xenofon D.
Computational Issues in Intelligent Control: Discrete-Event and Hybrid Systems Xenofon D discrete event and hybrid systems. Computational issues of various problems and al- gorithms concerning to address the control needs of complex systems that exhibit complicated dynamical behaviors. The design
Herbert, John
Symmetric versus asymmetric discretization of the integral equations in polarizable continuum form 28 April 2011 Available online 1 May 2011 a b s t r a c t Discretization of the integral equations of the integral operators. Consequently, the appropriate form of the finite-dimensional matrix equations
Capacity of the Discrete Memoryless Energy Harvesting Channel with Side Information
Yener, Aylin
Capacity of the Discrete Memoryless Energy Harvesting Channel with Side Information Omur Ozel1 to the available battery energy in that channel use. The capacity of this channel with only transmitter side, The Pennsylvania State University, University Park, PA 16802 Abstract--We determine the capacity of a discrete
A WEIGHTED FREQUENCY-DOMAIN LEAST SQUARES APPROACH FOR EQUALIZATION IN DISCRETE MULTITONE SYSTEMS
Adali, Tulay
chosen as the industry modulation standard for asymmetrical digital subscriber line (ADSL) modems [4 the energy and constellation size of each carrier. One implementation of MCM is the Discrete Multitone (DMT) system which uses the discrete Fourier transform (DFT) for modulation [2], [3]. DMT has recently been
The Capacity-Cost Function of Discrete Additive Noise Channels with and without Feedback
Wehlau, David
of discrete channels with memory. Index Terms { Channels with memory, additive noise, capacity-cost functionThe Capacity-Cost Function of Discrete Additive Noise Channels with and without Feedback #3; Fady by investigating the capacity- cost function (C (#12;)) of such additive noise channels without feedback. We
Passive Millimeter-Wave Ranging Using Discrete Lenses with Wave-Front Coding
Popovic, Zoya
of a receiving discrete lens with modulated amplitude and/or phase response. The result is a set of image pat on a relatively small (100-element) discrete lens antenna array with a cosinusoidal amplitude mask and half curve around 94 GHz. Waves in this fre- quency range penetrate through dust, fog and smoke
Hacker, Bradley R.
Discrete ultrahigh-pressure domains in the Western Gneiss Region, Norway: implications of Norway, Leiv Erikssons vei 39, 7491 Trondheim, Norway 4 Division of Geological and Planetary Sciences Ar ages within the Western Gneiss Region of Norway define three discrete ultrahigh-pressure (UHP
Call for Submissions -CanaDAM 2007 Canadian Discrete and Algorithmic Mathematics Conference 2007
Mohar, Bojan
Call for Submissions - CanaDAM 2007 Canadian Discrete and Algorithmic Mathematics Conference 2007 Banff Conference Center, Banff, Alberta, May 28-31, 2007 http://www.cs.ualberta.ca/mreza/CANADAM/ This is a new conference series on Discrete and Algorithmic Mathematics to be held in Canada every two years (in
Beylkin, Gregory
Discrete Radon Transform GREGORY BEYLKIN Abstract-This paper describes the discrete Radon transform (DRT showthattheDRTcan beused tocomputevariousgen- eralizations of the classical Radon transform (RT) and. An interesting observation is that the exact inversion algorithm cannot be obtained directly from Radon
Abdou, Mohamed
2007-01-01
Fusion Engineering and Design 82 (2007) 22332238 Application of discrete element method to study mechanical behaviors of ceramic breeder pebble beds Zhiyong An, Alice Ying, Mohamed Abdou Mechanical In this paper, the discrete element method (DEM) approach has been applied to study mechanical behaviors
Completeness in DiscreteTime Process Algebra Michel A. Reniers and Jan Joris Vereijken
Reniers, Michel
Completeness in DiscreteÂTime Process Algebra Michel A. Reniers and Jan Joris Vereijken Department, 1996 Abstract We prove soundness and completeness for some ACPÂstyle concrete, relativeÂtime, discrete . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.2 Soundness and Completeness . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 Basic
MAP-Inference on Large Scale Higher-Order Discrete Graphical Models by Fusion Moves
Schnörr, Christoph
MAP-Inference on Large Scale Higher-Order Discrete Graphical Models by Fusion Moves J¨org Hendrik reconsider the work of Lempitsky et al. 2010 on fusion moves and apply it to general discrete graphical models. We propose two alternatives for calculating fusion moves that outperform the standard in several
Melting in an Enclosure with Discrete Heating at a Constant Rate
Zhang, Yuwen
- Melting in an Enclosure with Discrete Heating at a Constant Rate Yuwen Zhang Zhongqi Chen Qijie · The melting of n-octadecane that is discretely heated at a constant rate from one side of an enclosure- Experimental Thermal and Fluid Science 1993; 6:196-201 rate heating mode of the melting process
Adaptability of a Discrete PSO Algorithm applied to the Traveling Salesman Problem with Fuzzy Data
Ludwig, Simone
Adaptability of a Discrete PSO Algorithm applied to the Traveling Salesman Problem with Fuzzy Data-known optimization method, Particle Swarm Optimization (PSO), when solving a fuzzy problem. The discrete PSO in order to study the impact of uncertain information in the quality of the results provided by PSO
Avanzini, Federico
Efficiency, accuracy, and stability issues in discrete-time simulations of single reed wind that when the continuous-time model is discretized, a delay-free path is generated in the computation for investigating experimentally the functioning of single reed wind instruments.13 A widely accepted ap- proach
An energy-momentum-conserving temporal discretization scheme for adhesive contact problems
An energy-momentum-conserving temporal discretization scheme for adhesive contact problems Sachin S' knowledge, none have been proposed for adhesive contact problems. In this work, an energy-momentum-conserving temporal discretization scheme for adhesive contact problems is proposed. A contact criterion is also
Discrete-time Lyapunov based small-gain theorem for parameterized interconnected ISS systems
Nesic, Dragan
Discrete-time Lyapunov based small-gain theorem for parameterized interconnected ISS systems Dina via the Lyapunov method. In particular, an ISS Lyapunov function for the overall system is constructed from the ISS Lyapunov functions of the two subsystems. We consider parameterized families of discrete
Lightweight Floating-Point Arithmetic: Case Study of Inverse Discrete Cosine Transform
Chen, Tsuhan
, customizable bit- width, rounding modes, low-power, inverse discrete cosine transform, video coding 1 of effort must be spent to manage the complexity, power consumption and time-to-market of the modernLightweight Floating-Point Arithmetic: Case Study of Inverse Discrete Cosine Transform Fang Fang
A DISCRETE CHOICE PEDESTRIAN BEHAVIOR MODEL FOR PEDESTRIAN DETECTION IN VISUAL TRACKING SYSTEMS
Bierlaire, Michel
A DISCRETE CHOICE PEDESTRIAN BEHAVIOR MODEL FOR PEDESTRIAN DETECTION IN VISUAL TRACKING SYSTEMS-based models. In this paper we propose the use of a discrete choice model (DCM) of pedestrian behavior and its application to the problem of the target detection in the particular case of pedestrian tracking. We analyze
Journal of Discrete Algorithms 4 (2006) 499510 www.elsevier.com/locate/jda
Dimitrios, Thilikos
2006-01-01
Journal of Discrete Algorithms 4 (2006) 499510 www.elsevier.com/locate/jda A 3-approximation reserved. doi:10.1016/j.jda.2005.06.004 #12;500 F.V. Fomin, D.M. Thilikos / Journal of Discrete Algorithms
Discrete Applied Mathematics 180 (2015) 135140 Contents lists available at ScienceDirect
Onn, Shmuel
2015-01-01
Discrete Applied Mathematics 180 (2015) 135140 Contents lists available at ScienceDirect Discrete Applied Mathematics journal homepage: www.elsevier.com/locate/dam Some efficiently solvable problems over@ie.technion.ac.il (S. Onn), v.shlyk@gmail.com, v.shlyk@outlook.com (V.A. Shlyk). http://dx.doi.org/10.1016/j.dam.2014
Discrete Applied Mathematics 180 (2015) 5269 Contents lists available at ScienceDirect
Deza, Antoine
2015-01-01
Discrete Applied Mathematics 180 (2015) 5269 Contents lists available at ScienceDirect Discrete Applied Mathematics journal homepage: www.elsevier.com/locate/dam How many double squares can a string@mcmaster.ca (A. Thierry). http://dx.doi.org/10.1016/j.dam.2014.08.016 0166-218X/© 2014 Elsevier B.V. All rights
Discrete Applied Mathematics 181 (2015) 3340 Contents lists available at ScienceDirect
Lu, Mei
2015-01-01
Discrete Applied Mathematics 181 (2015) 3340 Contents lists available at ScienceDirect Discrete Applied Mathematics journal homepage: www.elsevier.com/locate/dam Fault-tolerant maximal local: hql_2008@163.com (H. Liu), mlu@math.tsinghua.edu.cn (M. Lu). http://dx.doi.org/10.1016/j.dam.2014
Europhysics Letters PREPRINT Exploring the lower part of discrete polymer model energy
Stadler, Peter F.
Europhysics Letters PREPRINT Exploring the lower part of discrete polymer model energy landscapes a generic, problem independent algorithm for exploration of the low- energy portion of the energy landscape of discrete systems and apply it to the energy landscape of lattice proteins. Starting from a set of optimal
A Convective-like Energy-Stable Open Boundary Condition for Simulations of Incompressible Flows
Dong, Suchuan
2015-01-01
We present a new energy-stable open boundary condition, and an associated numerical algorithm, for simulating incompressible flows with outflow/open boundaries. This open boundary condition ensures the energy stability of the system, even when strong vortices or backflows occur at the outflow boundary. Under certain situations it can be reduced to a form that can be analogized to the usual convective boundary condition. One prominent feature of this boundary condition is that it provides a control over the velocity on the outflow/open boundary. This is not available with the other energy-stable open boundary conditions from previous works. Our numerical algorithm treats the proposed open boundary condition based on a rotational velocity-correction type strategy. It gives rise to a Robin-type condition for the discrete pressure and a Robin-type condition for the discrete velocity on the outflow/open boundary, respectively at the pressure and the velocity sub-steps. We present extensive numerical experiments on...
Suresh, Anil K [ORNL; Pelletier, Dale A [ORNL; Wang, Wei [ORNL; Broich, Michael L [ORNL; Moon, Ji Won [ORNL; Gu, Baohua [ORNL; Allison, David P [ORNL; Joy, David Charles [ORNL; Phelps, Tommy Joe [ORNL; Doktycz, Mitchel John [ORNL
2011-01-01
Nanocrystallites have garnered substantial interest due to their varying applications including catalysis. Consequently important aspects related to control of shape/size and syntheses through economical and non-hazardous means are desirable. Highly efficient bioreduction based natural fabrication approaches that utilize microbes and or -plant extracts are poised to meet these needs. Here we show that the gamma- proteobacterium, Shewanella oneidensis MR-1, can reduce tetrachloro aurate (III) ions, producing discrete extracellular spherical gold nanocrystallites. The particles were homogeneous with multiple size distributions and produced under ambient conditions at high yield, 88% of theoretical maximum. Further characterization revealed that the particles consist of spheres in the size range of 2-50 nm, with an average of 12 5 nm. The nanoparticles were hydrophilic, biocompatible, and resisted aggregation even after several months. The particles are likely capped by a detachable protein/peptide coat. UV-vis and Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive X-ray spectra and transmission electron microscopy measurements confirmed the formation as well the crystalline nature of the nanoparticles. The antibacterial activity of these gold nanoparticles was assessed using Gram-negative (E. coli and S. oneidensis) and Gram-positive (B. subtilis) bacteria. Toxicity assessments divulged that the particles were neither toxic nor inhibitory to any of these bacteria.
Wakefield acceleration in atmospheric plasmas: a possible source of MeV electrons
Arrayás, M; Seviour, R; Trueba, J L
2015-01-01
Intense electromagnetic pulses interacting with a plasma can create a wake of plasma oscillations. Electrons trapped in such oscillations can be accelerated under certain conditions to very high energies. We study the conditions for the wakefield acceleration to produce MeV electrons in atmospheric plasmas. This mechanism may explain the origin of MeV or runaway electrons needed in the current theories for the production of Terrestrial Gamma ray Flashes.
Wind Energy-Related Atmospheric Boundary Layer Large-Eddy Simulation Using OpenFOAM: Preprint
Churchfield, M.J.; Vijayakumar, G.; Brasseur, J.G.; Moriarty, P.J.
2010-08-01
This paper develops and evaluates the performance of a large-eddy simulation (LES) solver in computing the atmospheric boundary layer (ABL) over flat terrain under a variety of stability conditions, ranging from shear driven (neutral stratification) to moderately convective (unstable stratification).
Irwin, Mark E.
2005-01-01
conditional on observed (or forecasted) meteorology including temperature, humidity, pressure, and wind speed, defining the spatialtemporal extent of episodes of dangerous air quality, forecasting urban and areaAtmospheric Environment 39 (2005) 13731382 A hierarchical Bayesian model to estimate and forecast
Large-eddy Simulation of the Nighttime Stable Atmospheric Boundary Layer
Zhou, Bowen
2012-01-01
At nighttime, wind turbines extract more energy from thewind energy applications, MO similarity must be used with caution under strong stability conditions for predicting wind at turbineWind Energy 2 Abstract The near-surface structure of atmospheric turbulence affects the design and operation of wind turbines
2007-01-01
Atmospheric Environment 41 (2007) 18031818 Estimating the effects of increased urbanization School of Architecture, Planning & Preservation, Columbia University, NY, USA f Department of Geography this region from ``present-day'' (ca. 1990) conditions to a future year (ca. 2050), and these projections were
Shporer, Avi
2015-01-01
We identify 3 Kepler transiting planet systems, Kepler-7, Kepler-12, and Kepler-41, whose orbital phase-folded light curves are dominated by planetary atmospheric processes including thermal emission and reflected light, while the impact of non-atmospheric (i.e. gravitational) processes, including beaming (Doppler boosting) and tidal ellipsoidal distortion, is negligible. Therefore, those systems allow a direct view of their atmospheres without being hampered by the approximations used in the inclusion of both atmospheric and non-atmospheric processes when modeling the phase curve shape. Here we analyze Kepler-12b and Kepler-41b atmosphere based on their Kepler phase curve, while the analysis of Kepler-7b was presented elsewhere. The model we used efficiently computes reflection and thermal emission contributions to the phase curve, including inhomogeneous atmospheric reflection due to longitudinally varying cloud coverage. We confirm Kepler-12b and Kepler-41b show a westward phase shift between the brightest...
-focusing. It was predicted that diffractional spreading is suppressed for discrete solitons,4,5 which are known to possess demonstrate, for the first time to our knowledge, the existence of discrete gap solitons that display
February 17, 2002 14:24 WorldScienti c/ws lula Conservative Discretization of the
Preziosi, Luigi
February 17, 2002 14:24 WorldScienti c/ws lula Chapter 1 Conservative Discretization:24 WorldScienti c/ws lula 2 Conservative Discretization of the Boltzmann Equation and the Semicontinuous
2300 SYSTEM Conditioning Amplifier
Gellman, Andrew J.
2300 SYSTEM Signal Conditioning Amplifier 2310 Instruction Manual Vishay Micro-Measurements P date of shipment. Coverage of computers, cameras, rechargeable batteries, and similar items, sold on non-rechargeable batteries and similar consumable items is limited to the delivery of goods free from
Office of Energy Efficiency and Renewable Energy (EERE)
We take it for granted but what would life be like without the air conditioner? Once considered a luxury, this invention is now an essential, allowing us to cool everything from homes, businesses, businesses, data centers, laboratories and other buildings vital to our daily lives. Explore this timeline to learn some of the key dates in the history of air conditioning.
Lacey, Ph.D, P.E., Ronald E.
2012-07-16
Discrete Event Modeling of Algae Cultivation and Harvesting at Commercial Scale: Capital Costs, Operating Costs, and System Bottlenecks
Boyer, Edmond
decayed ice cover, we found surprisingly high pCO2sw (~290320 matm), considering that surface waterFurther observations of a decreasing atmospheric CO2 uptake capacity in the Canada Basin (Arctic as an atmospheric CO2 sink under the summertime ice-free conditions expected in the near future. Beneath a heavily
ORISE: Climate and Atmospheric Research
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you notHeatMaRIEdioxideUser WorkEP Power ConditioningClimate and
Peraire, Jaime
adaptation for high-order discretizations and simplex, cut-cell mesh generation. First, output-based mesh is presented for high-order (p > 1) discretizations, driven by an output-error estimate obtained fromA Simplex Cut-Cell Adaptive Method for High-Order Discretizations of the Compressible Navier
Aizenberg, Igor
Fresnel Functions and Transforms in an Arbitrary Discrete Basis Igor Aizenberg, Senior Member, IEEE, and Jaakko T. Astola, Fellow, IEEE Abstract--The idea of generalized Fresnel functions, which traces back discrete Fresnel functions and the generalized discrete Fresnel transforms for an arbitrary basis
Alcouffe, R.E.
1985-01-01
A difficult class of problems for the discrete-ordinates neutral particle transport method is to accurately compute the flux due to a spatially localized source. Because the transport equation is solved for discrete directions, the so-called ray effect causes the flux at space points far from the source to be inaccurate. Thus, in general, discrete ordinates would not be the method of choice to solve such problems. It is better suited for calculating problems with significant scattering. The Monte Carlo method is suited to localized source problems, particularly if the amount of collisional interactions in minimal. However, if there are many scattering collisions and the flux at all space points is desired, then the Monte Carlo method becomes expensive. To take advantage of the attributes of both approaches, we have devised a first collision source method to combine the Monte Carlo and discrete-ordinates solutions. That is, particles are tracked from the source to their first scattering collision and tallied to produce a source for the discrete-ordinates calculation. A scattered flux is then computed by discrete ordinates, and the total flux is the sum of the Monte Carlo and discrete ordinates calculated fluxes. In this paper, we present calculational results using the MCNP and TWODANT codes for selected two-dimensional problems that show the effectiveness of this method.
Biomechanical conditions of walking
Fan, Y F; Luo, L P; Li, Z Y; Han, S Y; Lv, C S; Zhang, B
2015-01-01
The development of rehabilitation training program for lower limb injury does not usually include gait pattern design. This paper introduced a gait pattern design by using equations (conditions of walking). Following the requirements of reducing force to the injured side to avoid further injury, we developed a lower limb gait pattern to shorten the stride length so as to reduce walking speed, to delay the stance phase of the uninjured side and to reduce step length of the uninjured side. This gait pattern was then verified by the practice of a rehabilitation training of an Achilles tendon rupture patient, whose two-year rehabilitation training (with 24 tests) has proven that this pattern worked as intended. This indicates that rehabilitation training program for lower limb injury can rest on biomechanical conditions of walking based on experimental evidence.
Necessary conditions for stabilization agreements
Yang, Zili.; Jacoby, Henry D.
The Climate Convention calls for stabilization of atmospheric concentrations of greenhouse gases. This paper considers the issues that must be faced in formulating a plan to meet any such target, using a proposed CO2 level ...
Ouchi, Y.; Otoshi, Sh.
1985-04-09
The air conditioning apparatus according to the invention comprises an absorption type heat pump comprising a system including an absorber, a regenerator, a condenser and an evaporator. A mixture of lithium bromide and zinc chloride is used as an absorbent which is dissolved to form an absorbent solution into a mixed solvent having a ratio by weight of methanol to water, the ratio falling in a range between 0.1 and 0.3. Said solution is circulated through the system.
High voltage pulse conditioning
Springfield, Ray M. (Sante Fe, NM); Wheat, Jr., Robert M. (Los Alamos, NM)
1990-01-01
Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.
Lokhandwala, Kaaeid A. (Union City, CA)
2000-01-01
A process for conditioning natural gas containing C.sub.3+ hydrocarbons and/or acid gas, so that it can be used as combustion fuel to run gas-powered equipment, including compressors, in the gas field or the gas processing plant. Compared with prior art processes, the invention creates lesser quantities of low-pressure gas per unit volume of fuel gas produced. Optionally, the process can also produce an NGL product.
Instrument intercomparison of glyoxal, methyl glyoxal and NO2 under simulated atmospheric conditions
2015-01-01
to an unheated 1/8 inch OD PTFE line (? 1 m length), whichoutside diameter), 1/4 inch ID (inside diameter) PTFE tube.Halfway along the cavity, a PTFE tee was used as an inlet
Defining integrals over connections in the discretized gravitational functional integral
V. M. Khatsymovsky
2010-05-01
Integration over connection type variables in the path integral for the discrete form of the first order formulation of general relativity theory is studied. The result (a generalized function of the rest of variables of the type of tetrad or elementary areas) can be defined through its moments, i. e. integrals of it with the area tensor monomials. In our previous paper these moments have been defined by deforming integration contours in the complex plane as if we had passed to an Euclidean-like region. In the present paper we define and evaluate the moments in the genuine Minkowsky region. The distribution of interest resulting from these moments in this non-positively defined region contains the divergences. We prove that the latter contribute only to the singular (\\dfun like) part of this distribution with support in the non-physical region of the complex plane of area tensors while in the physical region this distribution (usual function) confirms that defined in our previous paper which decays exponentially at large areas. Besides that, we evaluate the basic integrals over which the integral over connections in the general path integral can be expanded.
Discrete Mathematical Approaches to Graph-Based Traffic Analysis
Joslyn, Cliff A.; Cowley, Wendy E.; Hogan, Emilie A.; Olsen, Bryan K.
2014-04-01
Modern cyber defense and anlaytics requires general, formal models of cyber systems. Multi-scale network models are prime candidates for such formalisms, using discrete mathematical methods based in hierarchically-structured directed multigraphs which also include rich sets of labels. An exemplar of an application of such an approach is traffic analysis, that is, observing and analyzing connections between clients, servers, hosts, and actors within IP networks, over time, to identify characteristic or suspicious patterns. Towards that end, NetFlow (or more generically, IPFLOW) data are available from routers and servers which summarize coherent groups of IP packets flowing through the network. In this paper, we consider traffic analysis of Netflow using both basic graph statistics and two new mathematical measures involving labeled degree distributions and time interval overlap measures. We do all of this over the VAST test data set of 96M synthetic Netflow graph edges, against which we can identify characteristic patterns of simulated ground-truth network attacks.
Non-Abelian discrete gauge symmetries in F-theory
Grimm, Thomas W; Regalado, Diego
2015-01-01
The presence of non-Abelian discrete gauge symmetries in four-dimensional F-theory compactifications is investigated. Such symmetries are shown to arise from seven-brane configurations in genuine F-theory settings without a weak string coupling description. Gauge fields on mutually non-local seven-branes are argued to gauge both R-R and NS-NS two-form bulk axions. The gauging is completed into a generalisation of the Heisenberg group with either additional seven-brane gauge fields or R-R bulk gauge fields. The former case relies on having seven-brane fluxes, while the latter case requires torsion cohomology and is analysed in detail through the M-theory dual. Remarkably, the M-theory reduction yields an Abelian theory that becomes non-Abelian when translated into the correct duality frame to perform the F-theory limit. The reduction shows that the gauge coupling function depends on the gauged scalars and transforms non-trivially as required for the groups encountered. This field dependence agrees with the exp...
Non-Abelian discrete gauge symmetries in F-theory
Thomas W. Grimm; Tom G. Pugh; Diego Regalado
2015-04-23
The presence of non-Abelian discrete gauge symmetries in four-dimensional F-theory compactifications is investigated. Such symmetries are shown to arise from seven-brane configurations in genuine F-theory settings without a weak string coupling description. Gauge fields on mutually non-local seven-branes are argued to gauge both R-R and NS-NS two-form bulk axions. The gauging is completed into a generalisation of the Heisenberg group with either additional seven-brane gauge fields or R-R bulk gauge fields. The former case relies on having seven-brane fluxes, while the latter case requires torsion cohomology and is analysed in detail through the M-theory dual. Remarkably, the M-theory reduction yields an Abelian theory that becomes non-Abelian when translated into the correct duality frame to perform the F-theory limit. The reduction shows that the gauge coupling function depends on the gauged scalars and transforms non-trivially as required for the groups encountered. This field dependence agrees with the expectations for the kinetic mixing of seven-branes and is unchanged if the gaugings are absent.
Discrete Element Crowd Model for Pedestrian Evacuation Through an Exit
Lin, Peng; Lo, Siuming
2015-01-01
A series of accidents caused by crowd within the last decades evoked a lot of scientific interest in modeling the movement of pedestrian crowds. Based on discrete element method, a granular dynamic model, in which human body is simplified as self-driven sphere, is proposed to simulate the characteristics of crowd flow through an exit. In this model, the repulsive force among people is considered to have an anisotropic feature, and the physical contact force due to body deformation is quantified by the Hertz contact model. The movement of human body is simulated by applying the second Newton's law. The crowd flow through an exit at different desired velocities is studied and simulation results indicated that crowd flow exhibits three distinct states, i.e., smooth state, transition state and phase separation state. In the simulation, clogging phenomenon occurs more easily when the velocity of desired is high and the exit may as a result be totally blocked at a desired velocity of 1.6m/s or above, leading to fas...
Scalar potential model of redshift and discrete redshift
John C. Hodge
2006-02-15
On the galactic scale the universe is inhomogeneous and redshift $z$ is occasionally less than zero. A scalar potential model (SPM) that links the galaxy scale $z$ to the cosmological scale $z$ of the Hubble Law is postulated. Several differences among galaxy types suggest that spiral galaxies are Sources and that early type, lenticular, and irregular galaxies are Sinks of a scalar potential field. The morphology-radius and the intragalactic medium cluster observations support the movement of matter from Source galaxies to Sink galaxies. A cell structure of galaxy groups and clusters is proposed to resolve a paradox concerning the scalar potential like the Olber's paradox concerning light. For the sample galaxies, the ratio of the luminosity of Source galaxies to the luminosity of Sink galaxies approaches $2.7 \\pm 0.1$. An equation is derived from sample data, which is anisotropic and inhomogeneous, relating $z$ of and the distance $D$ to galaxies. The calculated $z$ has a correlation coefficient of 0.88 with the measured $z$ for a sample of 32 spiral galaxies with $D$ calculated using Cepheid variable stars. The equation is consistent with $zSPM of $z$ provides a physical basis for the $z$ of particle photons. Further, the SPM qualitatively suggests the discrete variations in $z$, which was reported by W. G. Tifft, 1997, Astrophy. J. 485, 465 and confirmed by others, are consistent with the SPM.
Entrainment of coarse grains using a discrete particle model
Valyrakis, Manousos; Arnold, Roger B. Jr.
2014-10-06
Conventional bedload transport models and incipient motion theories relying on a time-averaged boundary shear stress are incapable of accounting for the effects of fluctuating near-bed velocity in turbulent flow and are therefore prone to significant errors. Impulse, the product of an instantaneous force magnitude and its duration, has been recently proposed as an appropriate criterion for quantifying the effects of flow turbulence in removing coarse grains from the bed surface. Here, a discrete particle model (DPM) is used to examine the effects of impulse, representing a single idealized turbulent event, on particle entrainment. The results are classified according to the degree of grain movement into the following categories: motion prior to entrainment, initial dislodgement, and energetic displacement. The results indicate that in all three cases the degree of particle motion depends on both the force magnitude and the duration of its application and suggest that the effects of turbulence must be adequately accounted for in order to develop a more accurate method of determining incipient motion. DPM is capable of simulating the dynamics of grain entrainment and is an appropriate tool for further study of the fundamental mechanisms of sediment transport.
Composition and Reactions of Atmospheric Aerosol Particles
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
particles remain in the atmosphere can have a huge impact on the global climate. Measurements based on high-resolution scanning transmission x-ray images obtained at the ALS...
Transport impacts on atmosphere and climate: Aviation
2010-01-01
Environment 44 (2010) 4678–4734 Brunner, D. , Staehelin,Environment 44 (2010) 4678–4734 Vedantham, A. , Wuebbles,Environment 44 (2010) 4678–4734 global atmosphere’. In:
Uraninite and Fullerene in Atmospheric Particulates
Utsunomiya, Satoshi
incineration, uranium mining, and atmospheric testing of nuclearweapons-burning power plants typically contain very small amounts of uranium ( concentrations, the form of the uranium has been unknown. Using a variety of advanced electron microscopy
Discrete second-order Euler-Poincaré equations. Applications to optimal control
Leonardo Colombo; Fernando Jimenez; David Martin de Diego
2011-09-22
In this paper we will discuss some new developments in the design of numerical methods for optimal control problems of Lagrangian systems on Lie groups. We will construct these geometric integrators using discrete variational calculus on Lie groups, deriving a discrete version of the second-order Euler-Lagrange equations. Interesting applications as, for instance, a discrete derivation of the Euler-Poincar\\'e equations for second-order Lagrangians and its application to optimal control of a rigid body, and of a Cosserat rod are shown at the end of the paper.
Fehner and Gosling, Atmospheric Nuclear Weapons Testing, 1951...
Atmospheric Nuclear Weapons Testing, 1951-1963. Battlefield of the Cold War: The Nevada Test Site, Volume I Fehner and Gosling, Atmospheric Nuclear Weapons Testing, 1951-1963....
Doty, Sharon Lafferty
The faculty and students in the Atmospheric Sciences Department use physics, chemistry chemistry Atmospheric fluid dynamics Biosphere interactions Climate variability Clouds & storms Radiative, and mathematics to better understand the atmosphere and improve the prediction of its future state, both over
Atmospheric State, Cloud Microphysics and Radiative Flux
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Mace, Gerald
2008-01-15
Atmospheric thermodynamics, cloud properties, radiative fluxes and radiative heating rates for the ARM Southern Great Plains (SGP) site. The data represent a characterization of the physical state of the atmospheric column compiled on a five-minute temporal and 90m vertical grid. Sources for this information include raw measurements, cloud property and radiative retrievals, retrievals and derived variables from other third-party sources, and radiative calculations using the derived quantities.
Air Activation Following an Atmospheric Explosion
Lowrey, Justin D.; McIntyre, Justin I.; Prichard, Andrew W.; Gesh, Christopher J.
2013-03-13
In addition to thermal radiation and fission products, nuclear explosions result in a very high flux of unfissioned neutrons. Within an atmospheric nuclear explosion, these neutrons can activate the various elemental components of natural air, potentially adding to the radioactive signature of the event as a whole. The goal of this work is to make an order-of-magnitude estimate of the total amount of air activation products that can result from an atmospheric nuclear explosion.
Atmospheric State, Cloud Microphysics and Radiative Flux
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Mace, Gerald
Atmospheric thermodynamics, cloud properties, radiative fluxes and radiative heating rates for the ARM Southern Great Plains (SGP) site. The data represent a characterization of the physical state of the atmospheric column compiled on a five-minute temporal and 90m vertical grid. Sources for this information include raw measurements, cloud property and radiative retrievals, retrievals and derived variables from other third-party sources, and radiative calculations using the derived quantities.
Basalt-Atmosphere Interactions on Venus -
Treiman, Allan H.
Atmosphere? Â· CaAl2Si2O8 + SO3 CaSO4 + Al2SiO5 + SiO2 Â Anhydrite + andalusite + quartz !!! Â· Does this reaction proceed? Â Venus atmosphere est'd 0.2 - 0.3 ppt SO3. #12;Reaction Position Â· From this, very possible that SO3 is buffered! Â· But ... SO3 value is not known very well - who knows what is really going
Dimitra Atri; Adrian L. Melott; Brian C. Thomas
2010-05-03
A variety of events such as gamma-ray bursts and supernovae may expose the Earth to an increased flux of high-energy cosmic rays, with potentially important effects on the biosphere. Existing atmospheric chemistry software does not have the capability of incorporating the effects of substantial cosmic ray flux above 10 GeV . An atmospheric code, the NASA-Goddard Space Flight Center two-dimensional (latitude, altitude) time-dependent atmospheric model (NGSFC), is used to study atmospheric chemistry changes. Using CORSIKA, we have created tables that can be used to compute high energy cosmic ray (10 GeV - 1 PeV) induced atmospheric ionization and also, with the use of the NGSFC code, can be used to simulate the resulting atmospheric chemistry changes. We discuss the tables, their uses, weaknesses, and strengths.
Atmospheric Neutrinos in the MINOS Far Detector
Howcroft, Caius L.F.
2004-12-01
The phenomenon of flavour oscillations of neutrinos created in the atmosphere was first reported by the Super-Kamiokande collaboration in 1998 and since then has been confirmed by Soudan 2 and MACRO. The MINOS Far Detector is the first magnetized neutrino detector able to study atmospheric neutrino oscillations. Although it was designed to detect neutrinos from the NuMI beam, it provides a unique opportunity to measure the oscillation parameters for neutrinos and anti-neutrinos independently. The MINOS Far Detector was completed in August 2003 and since then has collected 2.52 kton-years of atmospheric data. Atmospheric neutrino interactions contained within the volume of the detector are separated from the dominant background from cosmic ray muons. Thirty seven events are selected with an estimated background contamination of less than 10%. Using the detector's magnetic field, 17 neutrino events and 6 anti-neutrino events are identified, 14 events have ambiguous charge. The neutrino oscillation parameters for {nu}{sub {mu}} and {bar {nu}}{sub {mu}} are studied using a maximum likelihood analysis. The measurement does not place constraining limits on the neutrino oscillation parameters due to the limited statistics of the data set analysed. However, this thesis represents the first observation of charge separated atmospheric neutrino interactions. It also details the techniques developed to perform atmospheric neutrino analyses in the MINOS Far Detector.
Simulation of Aerosol Behavior in a Saturated Atmosphere With the CONTAIN Code
Kljenak, Ivo; Mavko, Borut [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia)
2002-07-01
Experiments on aerosol behavior in an atmosphere containing saturated vapor, which were performed in the KAEVER experimental facility and proposed for the OECD International Standard Problem No. 44, were simulated with the CONTAIN thermal-hydraulic computer code. The purpose of the work was to assess the capability of the CONTAIN code to model aerosol condensation and deposition in a containment of a light-water-reactor nuclear power plant at severe accident conditions. Results of dry and wet aerosol concentrations in the test vessel atmosphere are presented and analyzed. (authors)
F-K Characteristics of the Seismic Response to a Set of Discrete Parallel Fractures
Vetri, Laura
2006-01-01
We model seismic wave propagation in a reservoir with discrete fracture zones using a finite difference scheme, which implements the Coates-Schoenberg formulation for fractured media. We study the variation of scattered ...
A DUALITY APPROACH TO THE GENEALOGIES OF DISCRETE NON-NEUTRAL WRIGHT-FISHER MODELS
Paris-Sud XI, Université de
A DUALITY APPROACH TO THE GENEALOGIES OF DISCRETE NON-NEUTRAL WRIGHT-FISHER MODELS THIERRY E), there is also some use of the duality concept in an attempt to understand the genealogies of a Wright
Quantization of systems with temporally varying discretization. II. Local evolution moves
Höhn, Philipp A.
2014-10-15
Several quantum gravity approaches and field theory on an evolving lattice involve a discretization changing dynamics generated by evolution moves. Local evolution moves in variational discrete systems (1) are a generalization of the Pachner evolution moves of simplicial gravity models, (2) update only a small subset of the dynamical data, (3) change the number of kinematical and physical degrees of freedom, and (4) generate a dynamical (or canonical) coarse graining or refining of the underlying discretization. To systematically explore such local moves and their implications in the quantum theory, this article suitably expands the quantum formalism for global evolution moves, constructed in Paper I [P. A. Höhn, “Quantization of systems with temporally varying discretization. I. Evolving Hilbert spaces,” J. Math. Phys. 55, 083508 (2014); e-print http://arxiv.org/abs/arXiv:1401.6062 [gr-qc
Theocharis, G.
We present a systematic study of the existence and stability of discrete breathers that are spatially localized in the bulk of a one-dimensional chain of compressed elastic beads that interact via Hertzian contact. The ...
Switching Between Discrete and Continuous Process Models to Predict Molecular Genetic Activity
Weld, Daniel Sabey
1984-05-01
Two kinds of process models have been used in programs that reason about change: Discrete and continuous models. We describe the design and implementation of a qualitative simulator, PEPTIDE, which uses both kinds of ...
John, Volker
.g., in the simulation of crystal growth [1] or of fuel cells [2]. The numerical solution of the time-dependent Navier results. Even for the two-dimen- sional laminar regime, the question of an optimal discretization approach
A three dimensional corner balance method for spatial discretization of the transport equation
Richardson, Rebecca Lynn
1994-01-01
The three-dimensional comer balance method is a new spatial discretization scheme for solving the transport equation on meshes consisting of "layers" of arbitrary polygonal meshes in the x-y plane. It is a conceptually and algebraically simple...
DOMINANT ATTRIBUTE AND MULTIPLE SCANNING APPROACHES FOR DISCRETIZATION OF NUMERICAL ATTRIBUTES
Rao, H. Shanker
2014-12-31
, respectively. These approaches were implemented as two explicit algorithms in a JAVA programming language and experiments were conducted by applying each algorithm separately on seventeen well known numerical data sets. The resulting discretized data sets were...
The multicomponent 2D Toda hierarchy: Discrete flows and string equations
Manuel Manas; Luis Martinez Alonso; Carlos Alvarez Fernandez
2009-01-21
The multicomponent 2D Toda hierarchy is analyzed through a factorization problem associated to an infinite-dimensional group. A new set of discrete flows is considered and the corresponding Lax and Zakharov--Shabat equations are characterized. Reductions of block Toeplitz and Hankel bi-infinite matrix types are proposed and studied. Orlov--Schulman operators, string equations and additional symmetries (discrete and continuous) are considered. The continuous-discrete Lax equations are shown to be equivalent to a factorization problem as well as to a set of string equations. A congruence method to derive site independent equations is presented and used to derive equations in the discrete multicomponent KP sector (and also for its modification) of the theory as well as dispersive Whitham equations.
A spatial multigrid iterative method for two-dimensional discrete-ordinates transport problems
Lansrud, Brian David
2005-08-29
Introduction to Chapter I............................................................ 1 The Discrete Transport Equation ............................................... 2 Examples of Current Iterative Transport Methods..................... 5................................................................... 16 Current Applications of Spatial-Multigrid Methods to SN Transport Problems........................................................... 17 Krylov Subspace Methods ......................................................... 21 Goals...
Violation of Continuous-Variable Einstein-Podolsky-Rosen Steering with Discrete Measurements
Schneeloch, James
In this Letter, we derive an entropic Einstein-Podolsky-Rosen (EPR) steering inequality for continuous-variable systems using only experimentally measured discrete probability distributions and details of the measurement ...
Space-time as a discrete field noncommutative causal network
G. L. Stavraki
2009-07-02
The necessity of rejecting the numerical model of geometrical extension is postulated on the basis of the idea of identity of space-time and physical vacuum. An attempt is made to define space-time not via the concept of manifold, but via the store of physical functions defined on it. The new description is based on the commutator representation of the causal structure of operator field theory. It is not the world point, but a universal field supermatrix complex U that is assumed to be the carrier of possible local events. This complex involves a complete set of Heisenberg local field operators together with their spin-group bases in the Fermi-field representation. The fundamental element of the extension is described in the model by the equation of a special commutator algebra closed on two such local complexes U_1 and U_2 "nearest" in the two-sided light-like connection and linked by a single virtual field interaction vertex. The discrete character of the constructed "quantum proximity" equation containing the gravitational constant is associated with the existence of local curvature on the Planck scale. Algebraic closed-ness of the basic equation suggests that the charge symmetry group should be group E_6 with non-standard representations of the fermion and scalar fields. On the basis of the calculated U expression we propose an effective superinvariant Lagrangian with fixed coefficients on the near-Planck scale, from which one can in principle try to obtain a low-energy limit for comparison with the real world.
Discrete Logarithms in GF(p) using the Number Field Sieve
Gordon, Dan
) Classification. 11Y16 1 Introduction Given a prime p and integers a and b, the discrete logarithm problem in GFMacchia [13], who solved the discrete logarithm problem modulo primes of 58 and 67 digits using the Gaussian a complex quadratic field to aid the sieving process. Define Lx[v; c] = exp{(c + o(1))(log x)v (log log x)1
Discrete Sampling Test Plan for the 200-BP-5 Operable Unit
Sweeney, Mark D.
2010-02-04
The Discrete Groundwater Sampling Project is conducted by the Pacific Northwest National Laboratory (PNNL) on behalf of CH2M HILL Plateau Remediation Company. The project is focused on delivering groundwater samples from proscribed horizons within select groundwater wells residing in the 200-BP-5 Operable Unit (200-BP-5 OU) on the Hanford Site. This document provides the scope, schedule, methodology, and other details of the PNNL discrete sampling effort.
Quantization of systems with temporally varying discretization. I. Evolving Hilbert spaces
Höhn, Philipp A.
2014-08-15
A temporally varying discretization often features in discrete gravitational systems and appears in lattice field theory models subject to a coarse graining or refining dynamics. To better understand such discretization changing dynamics in the quantum theory, an according formalism for constrained variational discrete systems is constructed. While this paper focuses on global evolution moves and, for simplicity, restricts to flat configuration spaces R{sup N}, a Paper II [P. A. Höhn, “Quantization of systems with temporally varying discretization. II. Local evolution moves,” J. Math. Phys., e-print http://arxiv.org/abs/arXiv:1401.7731 [gr-qc].] discusses local evolution moves. In order to link the covariant and canonical picture, the dynamics of the quantum states is generated by propagators which satisfy the canonical constraints and are constructed using the action and group averaging projectors. This projector formalism offers a systematic method for tracing and regularizing divergences in the resulting state sums. Non-trivial coarse graining evolution moves lead to non-unitary, and thus irreversible, projections of physical Hilbert spaces and Dirac observables such that these concepts become evolution move dependent on temporally varying discretizations. The formalism is illustrated in a toy model mimicking a “creation from nothing.” Subtleties arising when applying such a formalism to quantum gravity models are discussed.
Conditional sterility in plants
Meagher, Richard B. (Athens, GA); McKinney, Elizabeth (Athens, GA); Kim, Tehryung (Taejeon, KR)
2010-02-23
The present disclosure provides methods, recombinant DNA molecules, recombinant host cells containing the DNA molecules, and transgenic plant cells, plant tissue and plants which contain and express at least one antisense or interference RNA specific for a thiamine biosynthetic coding sequence or a thiamine binding protein or a thiamine-degrading protein, wherein the RNA or thiamine binding protein is expressed under the regulatory control of a transcription regulatory sequence which directs expression in male and/or female reproductive tissue. These transgenic plants are conditionally sterile; i.e., they are fertile only in the presence of exogenous thiamine. Such plants are especially appropriate for use in the seed industry or in the environment, for example, for use in revegetation of contaminated soils or phytoremediation, especially when those transgenic plants also contain and express one or more chimeric genes which confer resistance to contaminants.
Abiotic ozone and oxygen in atmospheres similar to prebiotic Earth
Domagal-Goldman, Shawn D.; Segura, Antígona; Claire, Mark W.; Robinson, Tyler D.; Meadows, Victoria S.
2014-09-10
The search for life on planets outside our solar system will use spectroscopic identification of atmospheric biosignatures. The most robust remotely detectable potential biosignature is considered to be the detection of oxygen (O{sub 2}) or ozone (O{sub 3}) simultaneous to methane (CH{sub 4}) at levels indicating fluxes from the planetary surface in excess of those that could be produced abiotically. Here we use an altitude-dependent photochemical model with the enhanced lower boundary conditions necessary to carefully explore abiotic O{sub 2} and O{sub 3} production on lifeless planets with a wide variety of volcanic gas fluxes and stellar energy distributions. On some of these worlds, we predict limited O{sub 2} and O{sub 3} buildup, caused by fast chemical production of these gases. This results in detectable abiotic O{sub 3} and CH{sub 4} features in the UV-visible, but no detectable abiotic O{sub 2} features. Thus, simultaneous detection of O{sub 3} and CH{sub 4} by a UV-visible mission is not a strong biosignature without proper contextual information. Discrimination between biological and abiotic sources of O{sub 2} and O{sub 3} is possible through analysis of the stellar and atmospheric context—particularly redox state and O atom inventory—of the planet in question. Specifically, understanding the spectral characteristics of the star and obtaining a broad wavelength range for planetary spectra should allow more robust identification of false positives for life. This highlights the importance of wide spectral coverage for future exoplanet characterization missions. Specifically, discrimination between true and false positives may require spectral observations that extend into infrared wavelengths and provide contextual information on the planet's atmospheric chemistry.
The coupling of winds, aerosols and chemistry in Titan's atmosphere
Hourdin, Chez Frédéric
REVIEW The coupling of winds, aerosols and chemistry in Titan's atmosphere BY SEBASTIEN LEBONNOIS 1'Ae´ronomie, IPSL, CNRS, BP3, 91371 Verrie`res le Buisson, France The atmosphere of Titan is a complex system, where the observed atmospheric structure of Titan's lower atmosphere (mainly in the stratosphere and troposphere
Phase of atmospheric secondary organic material affects its reactivity
of the reactivity of atmospheric SOM particles. atmospheric chemistry chemical aging organic aerosol collectionPhase of atmospheric secondary organic material affects its reactivity Mikinori Kuwata and Scot T of atmospheric organic particles among solid, semisolid, and liquid phases is of keen current scientific interest
ATM401, ATM601, CHEM601 Introduction to Atmospheric Sciences
Moelders, Nicole
as atmospheric chemistry. You should be able to read and analyze weather maps or climate diagrams, interpret as atmospheric chemistry. Fundamental goals are that you develop skills to think as an atmospheric scientistATM401, ATM601, CHEM601 Introduction to Atmospheric Sciences Fall 2013 Class time: TR 11:30am
Simulation and Theory of Ions at Atmospherically Relevant
Levin, Yan
Simulation and Theory of Ions at Atmospherically Relevant Aqueous Liquid-Air Interfaces Douglas J in the atmosphere influences air quality and climate. Molecular dy- namics simulations are becoming increasingly in the atmosphere. Here we review simulation studies of atmospherically relevant aqueous liquid-air interfaces
Biondini, Gino; Kova?i?, Gregor
2014-03-15
The inverse scattering transform for the focusing nonlinear Schrödinger equation with non-zero boundary conditions at infinity is presented, including the determination of the analyticity of the scattering eigenfunctions, the introduction of the appropriate Riemann surface and uniformization variable, the symmetries, discrete spectrum, asymptotics, trace formulae and the so-called theta condition, and the formulation of the inverse problem in terms of a Riemann-Hilbert problem. In addition, the general behavior of the soliton solutions is discussed, as well as the reductions to all special cases previously discussed in the literature.
Atmospheric and Wake Turbulence Impacts on Wind Turbine Fatigue Loading: Preprint
Lee, S.; Churchfield, M.; Moriarty, P.; Jonkman, J.; Michalakes, J.
2011-12-01
Large-eddy simulations of atmospheric boundary layers under various stability and surface roughness conditions are performed to investigate the turbulence impact on wind turbines. In particular, the aeroelastic responses of the turbines are studied to characterize the fatigue loading of the turbulence present in the boundary layer and in the wake of the turbines. Two utility-scale 5 MW turbines that are separated by seven rotor diameters are placed in a 3 km by 3 km by 1 km domain. They are subjected to atmospheric turbulent boundary layer flow and data is collected on the structural response of the turbine components. The surface roughness was found to increase the fatigue loads while the atmospheric instability had a small influence. Furthermore, the downstream turbines yielded higher fatigue loads indicating that the turbulent wakes generated from the upstream turbines have significant impact.
Development of Atmospheric Monitoring System at Akeno Observatory for the Telescope Array Project
T. Yamamoto; M. Teshima; M. Chikawa; N. Hayashida; S. Kawakami; N. Minagawa; Y. Morizane; M. Sasano; K. Yasui
2002-08-09
We have developed an atmospheric monitoring system for the Telescope Array experiment at Akeno Observatory. It consists of a Nd:YAG laser with an alt-azimuth shooting system and a small light receiver. This system is installed inside an air conditioned weather-proof dome. All parts, including the dome, laser, shooter, receiver, and optical devices are fully controlled by a personal computer utilizing the Linux operating system. It is now operated as a back-scattering LIDAR System. For the Telescope Array experiment, to estimate energy reliably and to obtain the correct shower development profile, the light transmittance in the atmosphere needs to be calibrated with high accuracy. Based on observational results using this monitoring system, we consider this LIDAR to be a very powerful technique for Telescope Array experiments. The details of this system and its atmospheric monitoring technique will be discussed.
3D cut-cell modelling for high-resolution atmospheric simulations
Yamazaki, H; Nikiforakis, N
2015-01-01
With the recent, rapid development of computer technology, the resolution of atmospheric numerical models has increased substantially. As a result, steep gradients in mountainous terrain are now being resolved in high-resolution models. This results in large truncation errors in those models using terrain-following coordinates. In this study, a new 3D Cartesian coordinate non-hydrostatic atmospheric model is developed. A cut-cell representation of topography based on finite-volume discretization is combined with a cell-merging approach, in which small cut-cells are merged with neighboring cells either vertically or horizontally. In addition, a block-structured mesh-refinement technique achieves a variable resolution on the model grid with the finest resolution occurring close to the terrain surface. The model successfully reproduces a flow over a 3D bell-shaped hill that shows a good agreement with the flow predicted by the linear theory. The ability of the model to simulate flows over steep terrain is demons...
Atmospheric Pressure Plasma Process And Applications
Peter C. Kong; Myrtle
2006-09-01
This paper provides a general discussion of atmospheric-pressure plasma generation, processes, and applications. There are two distinct categories of atmospheric-pressure plasmas: thermal and nonthermal. Thermal atmospheric-pressure plasmas include those produced in high intensity arcs, plasma torches, or in high intensity, high frequency discharges. Although nonthermal plasmas are at room temperatures, they are extremely effective in producing activated species, e.g., free radicals and excited state atoms. Thus, both thermal and nonthermal atmosphericpressure plasmas are finding applications in a wide variety of industrial processes, e.g. waste destruction, material recovery, extractive metallurgy, powder synthesis, and energy conversion. A brief discussion of recent plasma technology research and development activities at the Idaho National Laboratory is included.
Magnetized Atmospheres around Accreting Neutron Stars
S. Zane; R. Turolla; A. Treves
2000-02-01
We present a detailed investigation of atmospheres around accreting neutron stars with high magnetic field ($B\\gtrsim 10^{12}$ G) and low luminosity ($L\\lesssim 10^{33}$ erg/s). We compute the atmospheric structure, intensity and emergent spectrum for a plane-parallel, pure hydrogen medium by solving the transfer equations for the normal modes coupled to the hydrostatic and energy balance equations. The hard tail found in previous investigations for accreting, non-magnetic neutron stars with comparable luminosity is suppressed and the X-ray spectrum, although still harder than a blackbody at the star effective temperature, is nearly planckian in shape. Spectra from accreting atmospheres, both with high and low fields, are found to exhibit a significant excess at optical wavelengths above the Rayleigh-Jeans tail of the X-ray continuum.
A Community Atmosphere Model with Superparameterized Clouds
Randall, David; Branson, Mark; Wang, Minghuai; Ghan, Steven J.; Craig, Cheryl; Gettelman, A.; Edwards, Jim
2013-06-18
In 1999, National Center for Atmospheric Research (NCAR) scientists Wojciech Grabowski and Piotr Smolarkiewicz created a "multiscale" atmospheric model in which the physical processes associated with clouds were represented by running a simple high-resolution model within each grid column of a lowresolution global model. In idealized experiments, they found that the multiscale model produced promising simulations of organized tropical convection, which other models had struggled to produce. Inspired by their results, Colorado State University (CSU) scientists Marat Khairoutdinov and David Randall created a multiscale version of the Community Atmosphere Model (CAM). They removed the cloud parameterizations of the CAM, and replaced them with Khairoutdinov's high-resolution cloud model. They dubbed the embedded cloud model a "super-parameterization," and the modified CAM is now called the "SP-CAM." Over the next several years, many scientists, from many institutions, have explored the ability of the SP-CAM to simulate tropical weather systems, the day-night changes of precipitation, the Asian and African monsoons, and a number of other climate processes. Cristiana Stan of the Center for Ocean-Land-Atmosphere Interactions found that the SP-CAM gives improved results when coupled to an ocean model, and follow-on studies have explored the SP-CAM's utility when used as the atmospheric component of the Community Earth System Model. Much of this research has been performed under the auspices of the Center for Multiscale Modeling of Atmospheric Processes, a National Science Foundation (NSF) Science and Technology Center for which the lead institution is CSU.
Controlled Microdroplet Transport in an Atmospheric Pressure Microplasma
Maguire, P D; Kelsey, C P; Bingham, A; Montgomery, E P; Bennet, E D; Potts, H E; Rutherford, D; McDowell, D A; Diver, D A; Mariotti, D
2015-01-01
We report the controlled injection of near-isolated micron-sized liquid droplets into a low temperature He-Ne steady-state rf plasma at atmospheric pressure. The H2O droplet stream is constrained within a 2 mm diameter quartz tube. Imaging at the tube exit indicates a log-normal droplet size distribution with an initial count mean diameter of 15 micrometers falling to 13 micrometers with plasma exposure. The radial velocity profile is approximately parabolic indicating near laminar flow conditions with the majority of droplets travelling at >75% of the local gas speed and having a plasma transit time of chemistry effects. The successful demonstration of controlled microdroplet streams opens up possibilities for gas-phase microreactors and remote delivery of active species for pla...
Contamination of Dark Matter Experiments from Atmospheric Magnetic Dipoles
A. Bueno; M. Masip; P. Sánchez-Lucas; N. Setzer
2013-10-14
Dark matter collisions with heavy nuclei (Xe, Ge, Si, Na) may produce recoils observable at direct-search experiments. Given that some of these experiments are yielding conflicting information, however, it is worth asking if physics other than dark matter may produce similar nuclear recoils. We examine under what conditions an atmospherically-produced neutral particle with a relatively large magnetic dipole moment could fake a dark matter signal. We argue that a very definite flux could explain the signals seen at DAMA/LIBRA, CDMS/Si and CoGeNT consistently with the bounds from XENON100 and CDMS/Ge. To explore the plausibility of this scenario, we discuss a concrete model with 10-50 MeV sterile neutrinos that was recently proposed to explain the LSND and MiniBooNE anomalies.
Phenomena of oscillations in atmospheric pressure direct current glow discharges
Liu, Fu-cheng; Yan, Wen; Wang, De-zhen
2013-12-15
Self-sustained oscillations in a dc glow discharge with a semiconductor layer at atmospheric pressure were investigated by means of a one-dimensional fluid model. It is found that the dc glow discharge initially becomes unstable in the subnormal glow region and gives rise to oscillations of plasma parameters. A variety of oscillations with one or more frequencies have been observed under different conditions. The discharge oscillates between the glow discharge mode and the Townsend discharge mode in the oscillations with large amplitude while operates in the subnormal glow discharge mode all the while in the oscillations with small amplitude. Fourier Transform spectra of oscillations reveal the transition mechanism between different oscillations. The effects of semiconductor conductivity on the oscillation frequency of the dominant mode, gas voltage, as well as the discharge current have also been analyzed.
Controlled atmosphere for fabrication of cermet electrodes
Ray, Siba P. (Murrysville, PA); Woods, Robert W. (New Kensington, PA)
1998-01-01
A process for making an inert electrode composite wherein a metal oxide and a metal are reacted in a gaseous atmosphere at an elevated temperature of at least about 750.degree. C. The metal oxide is at least one of the nickel, iron, tin, zinc and zirconium oxides and the metal is copper, silver, a mixture of copper and silver or a copper-silver alloy. The gaseous atmosphere has an oxygen content that is controlled at about 5-3000 ppm in order to obtain a desired composition in the resulting composite.
Controlled atmosphere for fabrication of cermet electrodes
Ray, S.P.; Woods, R.W.
1998-08-11
A process is disclosed for making an inert electrode composite wherein a metal oxide and a metal are reacted in a gaseous atmosphere at an elevated temperature of at least about 750 C. The metal oxide is at least one of the nickel, iron, tin, zinc and zirconium oxides and the metal is copper, silver, a mixture of copper and silver or a copper-silver alloy. The gaseous atmosphere has an oxygen content that is controlled at about 5--3000 ppm in order to obtain a desired composition in the resulting composite. 2 figs.
Semiclassical energy conditions and wormholes
Prado Martin-Moruno
2014-11-17
We consider the nonlinear energy conditions and their quantum extensions. These new energy conditions behave much better than the usual pointwise energy conditions in the presence of semiclassical quantum effects. Analogous quantum extensions for the linear energy conditions are not always satisfied as one enters the quantum realm, but they can be used to constrain the violation of the classical conditions. Thus, the existence of wormholes supported by a fluid which violates the null energy condition in a controlled way is of particular interest.
Millimeter Wavelength Brightness Fluctuations of the Atmosphere Above the South Pole
R. S. Bussmann; W. L. Holzapfel; C. L. Kuo
2004-12-02
We report measurements of the millimeter wavelength brightness fluctuations produced by the atmosphere above the South Pole made with the Arcminute Cosmology Bolometer Array Receiver (ACBAR). The data span the 2002 Austral winter during which ACBAR was mounted on the Viper telescope at the South Pole. We recover the atmospheric signal in the presence of instrument noise by calculating the correlation between signals from distinct elements of the ACBAR bolometer array. With this method, it is possible to measure atmospheric brightness fluctuations with high SNR even under the most stable atmospheric conditions. The observed atmospheric signal is characterized by the parameters of the Komolgorov-Taylor (KT) model, which are the amplitude and power law exponent describing the atmospheric power spectrum, and the two components of the wind angular velocity at the time of the observation. The KT model is typically a good description of the observed fluctuations, and fits to the data produce values of the Komolgorov exponent that are consistent with theoretical expectations. By combining the wind angular velocity results with measurements of the wind linear velocity, we find that the altitude of the observed atmospheric fluctuations is consistent with the distribution of water vapor determined from radiosonde data. For data corresponding to frequency passbands centered on 150, 219, and 274 GHz, we obtain median fluctuation power amplitudes of [10, 38, 74] mK^{2} rad^{-5/3} in Rayleigh-Jeans temperature units. Comparing with previous work, we find that these median amplitudes are approximately an order of magnitude smaller than those found at the South Pole during the Austral summer and at least 30 times lower than found at the ALMA site in the Atacama desert.
Optimization of Air Conditioning Cycling
Seshadri, Swarooph
2012-10-19
Systems based on the vapor compression cycle are the most widely used in a variety of air conditioning applications. Despite the vast growth of modern control systems in the field of air conditioning systems, industry standard control is still...
DOCTORAL TRAINING GRANT (DTG) SCHEME TERMS AND CONDITIONS A Doctoral Training Grant (DTG. Doctoral Training Grants aim to: · assist the Research Organisation to attract the best people into postgraduate research and training; · allow a maximum of local discretion in managing and organising doctoral
When Does Aid Conditionality Work?
Montinola, Gabriella R.
2010-01-01
2005, the Group of Eight (G8) nations committed to increaseprogram conditions. Given the G8 industrialized nations’
Introducing Research College of Oceanic & Atmospheric Sciences
Barth, Jack
WECOMA Coll ege of Oceanic & Atmospheric Scie nces OREGON STATE UNIVERSITY in the O cean currents introduced by man (e.g., pollutants). Knowledge of upper-ocean currents is important for navigation and for search and rescue. The ocean currents off Oregon vary seasonally and can also vary from year to year
Introducing Research College of Oceanic & Atmospheric Sciences
Pierce, Stephen
.coas.oregonstate.edu WECOMA WECOMA Coll ege of Oceanic & Atmospheric Scie nces OREGON STATE UNIVERSITY in the O cean currents, to the south in summer and generally to the north in winter, create ocean currents. The strong summertime and the topography of the ocean floor influence the east-west cross-shelf currents. Understanding and being able
Quantifying chaos in the atmosphere Richard Washington
Washington, Richard
, Mansfield Road, Oxford OX1 3TB, UK Abstract: The atmosphere is known to be forced by a variety of energy sources, including radiation and heat fluxes emanating from the boundary layer associated with sea as the competing champions controlling process in the physical world. With or without Einstein, there can
The mean molecular mass of Titan's atmosphere
Withers, Paul
, Mars, Mars #12;Science Questions · Mean molecular mass (µ) -> Chemical composition · How did Titan form? · Current reservoirs of volatiles · Ethane/methane puddles/ocean · Thermal structure of atmosphere #12, delicate, etc T/p sensors are simple, cheap, reliable · Is it possible to know µ based on simple
Characterizing Titan's Upper Atmosphere Using the Titan
Johnson, Robert E.
methane chemical losses. INMS Data T-GITM Bell et al. [2010b] #12;Constraints on Escape · Parameter Sweep-Thermosphere Model (GITM) · 3-D, non-hydrostatic, altitude-based atmospheric model Compressible Navier (TVD) MUSCL Scheme. Block-based Massively Parallel Framework Updating with 4th order Runge
Connectivity To Atmospheric Release Advisory Capability
Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]
2001-02-26
To establish DOE and NNSA connectivity to Atmospheric Release Advisory Capability (ARAC) for sites and facilities that have the potential for releasing hazardous materials sufficient to generate certain emergency declarations and to promote efficient use of resources for consequence assessment activities at DOE sites, facilities, operations, and activities in planning for and responding to emergency events. No cancellations.
Atmospheric Chemistry, Modeling, and Biogeochemistry of Mercury
activities that release mercury to the atmosphere include coal burning, industrial processes, waste incine and climate projections; critically and quantitatively analyze environmental management and policy proposals mercury research. Global Budget of Mercury Prior to the onset of human industrial activities, the amount
Azores Global Atmosphere Monitoring Complex 1. INTRODUCTION
Honrath, Richard E.
observations. Prior to the advent of satellite observations, they provided weather data critical to the accuracy of European weather forecasts. Today, they provide a unique base for studies of atmospheric Monitoring Complex (AGAMC) is a set of ground-based measurement stations for use in sampling the marine
MIDDLE ATMOSPHERE DYNAMICS AT707 (3 credits)
Collett Jr., Jeffrey L.
.8 Static Stability Structure 9.9 Gravity Wave Generation in Unbalanced JetFront Systems 10. Equatorial, T. G., 2007: Transport in the Middle Atmosphere. J. Meteorol. Soc. Japan, 85B, 165191. 1 #12. Vertically Propagating Waves 2.1 Extratropical (Planetary) Rossby Waves 2.2 Extratropical Gravity Waves 2
Atmospheric aerosol light scattering and polarization peculiarities
Patlashenko, Zh I
2015-01-01
This paper considers environmental problems of natural and anthropogenic atmospheric aerosol pollution and its global and regional monitoring. Efficient aerosol investigations may be achieved by spectropolarimetric measurements. Specifically second and fourth Stokes parameters spectral dependencies carry information on averaged refraction and absorption indexes and on particles size distribution functions characteristics.
THE LOWER SOLAR ATMOSPHERE ROBERT J. RUTTEN
Rutten, Rob
over large fields, long times and many wave- lengths (heights) simultaneously -- Judge and Peter (1998THE LOWER SOLAR ATMOSPHERE ROBERT J. RUTTEN Sterrekundig Instituut, Postbus 80 000, NLÂ3508 TA, Utrecht, The Netherlands Abstract. This "rapporteur" report discusses the solar photosphere and low
Modeling of Alpine Atmospheric Dynamics II
Gohm, Alexander
Modeling of Alpine Atmospheric Dynamics II 707.424, VU 2, SS2005 Unit 7: Model code structure: mesoscale convective system 17-18 April 2004: Sierra hydraulic jump case 21 January 2005: the "Universiade) Introduction (brief description of the phenomenon and a description of the model and of the measurements
Dynamics of Jupiter's Atmosphere Andrew P. Ingersoll
. Dowling University of Louisville Peter J. Gierasch Cornell University Glenn S. Orton Jet Propulsion no topography, i.e., no con- tinents or oceans; its atmosphere merges smoothly with the planet's fluid interior with falling ice and rain. On Jupiter, the separation mechanism is still to be determined. The winds of Jupiter
JournalofGeophysicalResearch: Atmospheres RESEARCH ARTICLE
Raible, Christoph C.
MAR 2015 The influence of absorbed solar radiation by Saharan dust on hurricane genesis Sebastian, Bern, Switzerland Abstract To date, the radiative impact of dust and the Saharan air layer (SAL the atmosphere due to absorption of solar radiation but thus shifts convection to regions more conducive
INTRODUCTION Atmospheric aerosol particles influence the Earth's
Wunderle, Stefan
, scattering, and absorbing solar electromagnetic radiation and by modifying cloud properties due to their roleINTRODUCTION Atmospheric aerosol particles influence the Earth's radiation budget by reflecting to maximum cover a region once in the daytime. In contrary, up-to-date geostationary instruments like
ATMOSPHERIC SCIENCE LETTERS Atmos. Sci. Let. (2015)
2015-01-01
of the monsoon forecasting models, which many times do not represent the heat energy available to the atmosphere, have a great demand for accurate, long range forecast (LRF) of mon- soon rainfall, which has always. We studied the impacts of ocean mean temperature (OMT), representing the heat energy of the upper
Exploring the Deep... Ocean-Atmosphere
Wright, Dawn Jeannine
and the transfer of energy among these systems. Global energy balance The Sun is the primary source of energy), and biosphere (living organisms) that are driven by solar energy. The ocean and the atmosphere have the greatest on the others. To fully understand the dynamics of our climate, we must examine the global energy balance
SUPPLEMENTARY Submitted to: Atmospheric Chemistry and Physics
Meskhidze, Nicholas
S1 SUPPLEMENTARY Submitted to: Atmospheric Chemistry and Physics Title: Quantifying/fuels/emission control devices for coal-fired power plants by province. Table S4. The uncertainties of unabated emission Ratio of biomass burning Normal (Province dependent) Questionnaire: Wang and Zhang (2008) B 1 A
Energy conditions and their implications
Visser, Matt
Energy conditions and their implications Matt Visser Physics Department Washington University Saint;#16;s (Los Alamos) Midwest Relativity 9 November 1999. #12; Abstract: The energy conditions of general- itational #12;elds and cosmological geometries. However, the energy conditions are beginning to look a lot
TTProblem A Air Conditioning Machinery
California at Berkeley, University of
TTProblem A Air Conditioning Machinery Input file: ducts.in You are a technician for the Air Conditioning Machinery company (ACM). Unfortunately, when you arrive at a customer site to install some air conditioning ducts, you discover that you are running low on supplies. You have only six duct segments
Atmospheric Radiation Measurement Program facilities newsletter, November 2002.
Holdridge, D. J.
2002-12-03
Fall 2002 Intensive Operation Periods: Single Column Model and Unmanned Aerospace Vehicle--In an Intensive Operation Period (IOP) on November 3-23, 2002, researchers at the SGP CART site are collecting a detailed data set for use in improving the Single Column Model (SCM), a scaled-down climate model. The SCM represents one vertical column of air above Earth's surface and requires less computation time than a full-scale global climate model. Researchers first use the SCM to efficiently improve submodels of clouds, solar radiation transfer, and atmosphere-surface interactions, then implement the results in large-scale global models. With measured values for a starting point, the SCM predicts atmospheric variables during prescribed time periods. A computer calculates values for such quantities as the amount of solar radiation reaching the surface and predicts how clouds will evolve and interact with incoming light from the sun. Researchers compare the SCM's predictions with actual measurements made during the IOP, then adjust the submodels to make predictions more reliable. A second IOP conducted concurrently with the SCM IOP involves high-altitude, long-duration aircraft flights. The original plan was to use an unmanned aerospace vehicle (UAV), but the National Aeronautics and Space Administration (NASA) aircraft Proteus will be substituted because all UAVs have been deployed elsewhere. The UAV is a small, instrument-equipped, remote-control plane that is operated from the ground by a computer. The Proteus is a manned aircraft, originally designed to carry telecommunications relay equipment, that can be reconfigured for uses such as reconnaissance and surveillance, commercial imaging, launching of small space satellites, and atmospheric research. The plane is designed for two on-board pilots in a pressurized cabin, flying to altitudes up to 65,000 feet for as long as 18 hours. The Proteus has a variable wingspan of 77-92 feet and is 56 feet long. The plane can carry up to 7,260 pounds of equipment, making it a versatile research tool. The Proteus is making measurements at the very top of the cirrus cloud layer to characterize structures of these clouds. These new measurements will provide more accurate, more abundant data for use in improving the representation of clouds in the SCM. 2002-2003 Winter Weather Forecast--Top climate forecasters at the National Oceanic and Atmospheric Administration's (NOAA's) Climate Prediction Center say that an El Nino condition in the tropical Pacific Ocean will influence our winter weather this year. Although this El Nino is not as strong as the event of the 1997-1998 winter season, the United States will nevertheless experience some atypical weather. Strong impacts could be felt in several areas. Nationally, forecasters are predicting warmer-than-average temperatures over the northern tier of states and wetter-than-average conditions in the southern tier of states during the 2002-2003 winter season. Kansas residents should expect warmer and wetter conditions, while Oklahoma will be wetter than average.
Processing materials inside an atmospheric-pressure radiofrequency nonthermal plasma discharge
Selwyn, Gary S.; Henins, Ivars; Park, Jaeyoung; Herrmann, Hans W.
2006-04-11
Apparatus for the processing of materials involving placing a material either placed between an radio-frequency electrode and a ground electrode, or which is itself one of the electrodes. This is done in atmospheric pressure conditions. The apparatus effectively etches or cleans substrates, such as silicon wafers, or provides cleaning of spools and drums, and uses a gas containing an inert gas and a chemically reactive gas.
Jan L. Cie?li?ski; Anatolij K. Prykarpatski
2014-03-27
We investigate discretizations of the integrable discrete nonlinear Schr\\"odinger dynamical system and related symplectic structures. We develop an effective scheme of invariant reducing the corresponding infinite system of ordinary differential equations to an equivalent finite system of ordinary differential equations with respect to the evolution parameter. We construct a finite set of recurrent algebraic regular relations allowing to generate solutions of the discrete nonlinear Schr\\"odinger dynamical system and we discuss the related functional spaces of solutions. Finally, we discuss the Fourier transform approach to studying the solution set of the discrete nonlinear Schr\\"odinger dynamical system and its functional-analytical aspects.
Staggered grids discretization in three-dimensional Darcy convection
B. Karasozen; A. D. Nemtsev; V. G. Tsybulin
2008-02-17
We consider three-dimensional convection of an incompressible fluid saturated in a parallelepiped with a porous medium. A mimetic finite-difference scheme for the Darcy convection problem in the primitive variables is developed. It consists of staggered nonuniform grids with five types of nodes, differencing and averaging operators on a two-nodes stencil. The nonlinear terms are approximated using special schemes. Two problems with different boundary conditions are considered to study scenarios of instability of the state of rest. Branching off of a continuous family of steady states was detected for the problem with zero heat fluxes on two opposite lateral planes.
Discrete Self-Similarity Of RR Lyrae Stars II. Period Spectrum For A Very Large Sample
R. L. Oldershaw
2006-06-06
A recent paper demonstrated a considerable degree of self-similarity between RR Lyrae stars and their atomic scale analogues: excited helium atoms undergoing single-level transition between n = 7 and n = 10. Discrete self-similarity between these fractal analogues was indentified in terms of their masses, radii, oscillation periods, basic morphologies and kinematics. In this second paper on the subject, an extremely large and carefully analyzed sample of RR Lyrae oscillation periods provides further evidence for a unique match between the predicted set of discrete periods, based exclusively on the known helium spectrum and the discrete scaling equations of a fractal cosmological paradigm, and the observed period spectra of RR Lyrae stars.
Correction terms for propagators and d'Alembertians due to spacetime discreteness
Steven Johnston
2014-11-10
The causal set approach to quantum gravity models spacetime as a discrete structure - a causal set. Recent research has led to causal set models for the retarded propagator for the Klein-Gordon equation and the d'Alembertian operator. These models can be compared to their continuum counterparts via a sprinkling process. It has been shown that the models agree exactly with the continuum quantities in the limit of an infinite sprinkling density - the continuum limit. This paper obtains the correction terms for these models for sprinkled causal sets with a finite sprinkling density. These correction terms are an important step towards testable differences between the continuum and discrete models that could provide evidence of spacetime discreteness.
Discrete-time Lyapunov design for neuroadaptive control of elastic-joint robots
Macnab, C.J.B.; D'Eleuterio, G.M.T.
2000-05-01
A neural-network controller operating in discrete time is shown to result in stable trajectory tracking for rigid and elastic-joint robots. The technique assumes continuous-time state feedback. The proof of stability uses discrete-time Lyapunov functions. For the elastic-joint case, a discrete-time version of the adaptive backstepping technique is used. The result is that the neural network can be run at a very slow control rate, suitable for online calculations. The neural network used is referred to as the CMAC-RBF Associative Memory (CRAM), a modification of Albus's Cerebellar Model Arithmetic Computer (CMAC) algorithm using radial basis functions (RBFs). Simulation results are provided for a two-link planar elastic-joint robot and show that performance can be improved by using a larger network at a slower control rate.
Comparison of discrete and continuous thermal neutron scattering treatments in MCNP5
Pavlou, A. T. [Univ. of Michigan, Dept. of Nuclear Engineering and Radiological Sciences, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Brown, F. B. [Los Alamos National Laboratory, Monte Carlo Codes Group, MS A143, PO Box 1663, Los Alamos, NM 87545 (United States); Martin, W. R. [Univ. of Michigan, Dept. of Nuclear Engineering and Radiological Sciences, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Kiedrowski, B. C. [Los Alamos National Laboratory, Monte Carlo Codes Group, MS A143, PO Box 1663, Los Alamos, NM 87545 (United States)
2012-07-01
The standard discrete thermal neutron S({alpha},{beta}) scattering treatment in MCNP5 is compared with a continuous S({alpha},{beta}) scattering treatment using a criticality suite of 119 benchmark cases and ENDF/B-VII.0 nuclear data. In the analysis, six bound isotopes are considered: beryllium metal, graphite, hydrogen in water, hydrogen in polyethylene, beryllium in beryllium oxide and oxygen in beryllium oxide. Overall, there are only small changes in the eigenvalue (k{sub eff}) between discrete and continuous treatments. In the comparison of 64 cases that utilize S({alpha},{beta}) scattering, 62 agreed at the 95% confidence level, and the 2 cases with differences larger than 3 {sigma} agreed within 1 {sigma} when more neutrons were run in the calculations. The results indicate that the changes in eigenvalue between continuous and discrete treatments are random, small, and well within the uncertainty of measured data for reactor criticality experiments. (authors)
Unified theory of exactly and quasiexactly solvable ''discrete'' quantum mechanics. I. Formalism
Odake, Satoru [Department of Physics, Shinshu University, Matsumoto 390-8621 (Japan); Sasaki, Ryu [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)
2010-08-15
We present a simple recipe to construct exactly and quasiexactly solvable Hamiltonians in one-dimensional ''discrete'' quantum mechanics, in which the Schroedinger equation is a difference equation. It reproduces all the known ones whose eigenfunctions consist of the Askey scheme of hypergeometric orthogonal polynomials of a continuous or a discrete variable. The recipe also predicts several new ones. An essential role is played by the sinusoidal coordinate, which generates the closure relation and the Askey-Wilson algebra together with the Hamiltonian. The relationship between the closure relation and the Askey-Wilson algebra is clarified.
Resolution Limits for Resonant Mems Sensors Based on Discrete Relay Feedback Techniques
Juillard, J; Domínguez, M; Pons, Joan; Ricart, J
2007-01-01
This paper is devoted to the analysis of resonant MEMS sensors based on discrete relay feedback techniques. One drawback of such techniques is that some synchronization usually occurs between the discrete part and the continuous part of the system: this results in sensor responses that are very similar to the curves known as devil's staircases, i.e. the frequency does not vary smoothly with the sensor's input. The main contribution of this paper is a theoretical calculation of the resolution of such systems. The resolutions of two existing resonant MEMS architectures are then calculated and these results are discussed.
Dynamics and Light Propagation in a Universe with Discrete Matter Content
Mohamad Shalaby
2012-06-06
We discuss a model for a universe with discrete matter content instead of the continuous perfect fluid taken in FRW models. We show how the redshift in such a universe deviates from the corresponding one in an FRW cosmology. This illustrates the fact that averaging the matter content in a universe and then evolving it in time, is not the same as evolving a universe with discrete matter content. The main reason for such deviation is the fact that the photons in such a universe mainly travel in an empty space rather than the continuous perfect fluid in FRW geometry.
Numerical study on microwave-sustained argon discharge under atmospheric pressure
Yang, Y.; Hua, W., E-mail: huaw@scu.edu.cn; Guo, S. Y. [School of Electronics and Information Engineering, Sichuan University, Chengdu 610065 (China)] [School of Electronics and Information Engineering, Sichuan University, Chengdu 610065 (China)
2014-04-15
A numerical study on microwave sustained argon discharge under atmospheric pressure is reported in this paper. The purpose of this study is to investigate both the process and effects of the conditions of microwave-excited gas discharge under atmospheric pressure, thereby aiding improvements in the design of the discharge system, setting the appropriate working time, and controlling the operating conditions. A 3D model is presented, which includes the physical processes of electromagnetic wave propagation, electron transport, heavy species transport, gas flow, and heat transfer. The results can be obtained by means of the fluid approximation. The maxima of the electron density and gas temperature are 4.96?×?10{sup 18} m{sup ?3} and 2514.8?K, respectively, and the gas pressure remains almost unchanged for typical operating conditions with a gas flow rate of 20 l/min, microwave power of 1000 W, and initial temperature of 473?K. In addition, the conditions (microwave power, gas flow rate, and initial temperature) of discharge are varied to obtain deeper information about the electron density and gas temperature. The results of our numerical study are valid and clearly describe both the physical process and effects of the conditions of microwave-excited argon discharge.
Ernest S. Colantonio College of Earth, Ocean, and Atmospheric Sciences
Kurapov, Alexander
) and document imaging and workflow processing system (Nolij); developed data warehouse queries; identifiedErnest S. Colantonio College of Earth, Ocean, and Atmospheric Sciences Oregon State University State University, College of Earth, Ocean, and Atmospheric Sciences Faculty Research Assistant Conduct
BIOSIGNATURE GASES IN H?-DOMINATED ATMOSPHERES ON ROCKY EXOPLANETS
Seager, Sara
Super-Earth exoplanets are being discovered with increasing frequency and some will be able to retain stable H2-dominated atmospheres. We study biosignature gases on exoplanets with thin H2 atmospheres and habitable surface ...
Effect of furnace atmosphere on E-glass foaming
Kim, D. S.; Dutton, Bryan C.; Hrma, Pavel R.; Pilon, Laurent
2006-01-01
Fig. 6. Fig. 7. Fig. 8. and furnace temperature versus timein air-based atmospheres and furnace temperature versus time2 -based atmospheres and furnace temperature versus time for
Author's Accepted Manuscript ORBIT-CENTERED ATMOSPHERIC DENSITY
Wohlberg, Brendt
solar and geomagnetic activities and different prediction windows. Compar- ison with previouslyAuthor's Accepted Manuscript ORBIT-CENTERED ATMOSPHERIC DENSITY PREDICTION USING ARTIFICIAL NEURAL Shoemaker, Riccardo Bevilacqua, ORBIT-CENTERED ATMOSPHERIC DENSITY PREDICTION USING ARTIFICIAL NEURAL
Mesoscale coupled ocean-atmosphere feedbacks in boundary current systems
Putrasahan, Dian Ariyani
2012-01-01
Isolating Mesoscale Coupled Ocean-Atmosphere in the KuroshioSST coupler . . . . Chapter 3 Mesoscale Ocean-Atmosphere4.2 Impact of Mesoscale SST on Precipitation Chapter 4 vi
A Temperature and Abundance Retrieval Method for Exoplanet Atmospheres
Madhusudhan, Nikku
We present a new method to retrieve molecular abundances and temperature profiles from exoplanet atmosphere photometry and spectroscopy. We run millions of one-dimensional (1D) atmosphere models in order to cover the large ...
U. S. Department of Commerce National Oceanic and Atmospheric Administration
U. S. Department of Commerce National Oceanic and Atmospheric Administration National Coastal Data Area Network) Project Description: The National Oceanic and Atmospheric Administration's (NOAA consists of four separate components, an administrative local area network (LAN) component; a public access
EPS 22 The Fluid Earth: Oceans, Atmosphere, Climate & Environment
Huybers, Peter
. Students are requested not to use laptops or cell phones during class. Textbook: The Atmospheric Balance 02 Feb Atmospheric radiation. Demonstration: Invisibility at 1800 K. Spectra and Planck's Nobel
ATMOS 5000: Intro to Atmospheric Science Fall Term 2013
Lin, John Chun-Han
allows: · Atmospheric boundary layer · Carbon cycle, CO2 · Ozone hole, stratospheric chemistry · Air on the atmospheric controls on the weather (beach volleyball versus a rainy day indoors, skiing on a sunny day
Magnetospheric structure and atmospheric Joule heating of habitable planets orbiting M-dwarf stars
Cohen, O.; Drake, J. J.; Garraffo, C.; Poppenhaeger, K.; Glocer, A.; Ridley, A. J.; Gombosi, T. I.
2014-07-20
We study the magnetospheric structure and the ionospheric Joule Heating of planets orbiting M-dwarf stars in the habitable zone using a set of magnetohydrodynamic models. The stellar wind solution is used to drive a model for the planetary magnetosphere, which is coupled with a model for the planetary ionosphere. Our simulations reveal that the space environment around close-in habitable planets is extreme, and the stellar wind plasma conditions change from sub- to super-Alfvénic along the planetary orbit. As a result, the magnetospheric structure changes dramatically with a bow shock forming in the super-Alfvénic sectors, while no bow shock forms in the sub-Alfvénic sectors. The planets reside most of the time in the sub-Alfvénic sectors with poor atmospheric protection. A significant amount of Joule Heating is provided at the top of the atmosphere as a result of the intense stellar wind. For the steady-state solution, the heating is about 0.1%-3% of the total incoming stellar irradiation, and it is enhanced by 50% for the time-dependent case. The significant Joule Heating obtained here should be considered in models for the atmospheres of habitable planets in terms of the thickness of the atmosphere, the top-side temperature and density, the boundary conditions for the atmospheric pressure, and particle radiation and transport. Here we assume constant ionospheric Pedersen conductance similar to that of the Earth. The conductance could be greater due to the intense EUV radiation leading to smaller heating rates. We plan to quantify the ionospheric conductance in future study.
Atmospheric rivers as Lagrangian coherent structures
Garaboa, Daniel; Huhn, Florian; Perez-Muńuzuri, Vicente
2015-01-01
We show that filamentous Atmospheric Rivers (ARs) over the Northern Atlantic Ocean are closely linked to attracting Lagrangian Coherent Structures (LCSs) in the large scale wind field. LCSs represent lines of attraction in the evolving flow with a significant impact on all passive tracers. Using Finite-Time Lyapunov Exponents (FTLE), we extract LCSs from a two-dimensional flow derived from water vapor flux of atmospheric reanalysis data and compare them to the three-dimensional LCS obtained from the wind flow. We correlate the typical filamentous water vapor patterns of ARs with LCSs and find that LCSs bound the filaments on the back side. Passive advective transport of water vapor from tropical latitudes is potentially possible.
Atmospheric Neutrino Oscillations for Earth Tomography
Winter, Walter
2015-01-01
Modern proposed atmospheric neutrino oscillation experiments, such as PINGU in the Antarctic ice or or ORCA in Mediterranean sea water, aim for precision measurements of the oscillation parameters including the ordering of the neutrino masses. They can, however, go far beyond that: Since neutrino oscillations are affected by the coherent forward scattering with matter, neutrinos can provide a new view on the interior of the earth. We show that the proposed atmospheric oscillation experiments can robustly measure the lower mantle density of the earth with a precision at the level of 4-5 percent, including the uncertainties of the oscillation parameters and correlations among different density layers. While the earth's core is, in principle, accessible by the angular resolution, new technology would be required to extract degeneracy-free information.
Measuring Magnetic Fields in the Solar Atmosphere
de Wijn, A G
2012-01-01
Since the discovery by Hale in the early 1900s that sunspots harbor strong magnetic field, magnetism has become increasingly important in our understanding of processes on the Sun and in the Heliosphere. Many current and planned instruments are capable of diagnosing magnetic field in the solar atmosphere. Photospheric magnetometry is now well-established. However, many challenges remain. For instance, the diagnosis of magnetic field in the chromosphere and corona is difficult, and interpretation of measurements is harder still. As a result only very few measurements have been made so far, yet it is clear that if we are to understand the outer solar atmosphere we must study the magnetic field. I will review the history of solar magnetic field measurements, describe and discuss the three types of magnetometry, and close with an outlook on the future.
Performance of the STACEE Atmospheric Cherenkov Telescope
STACEE Collaboration; D. A. Williams; D. Bhattacharya; L. M. Boone; M. C. Chantell; Z. Conner; C. E. Covault; M. Dragovan; P. Fortin; D. Gingrich; D. T. Gregorich; D. S. Hanna; G. Mohanty; R. Mukherjee; R. A. Ong; S. Oser; K. Ragan; R. A. Scalzo; D. R. Schuette; C. G. Theoret; T. O. Tumer; F. Vincent; J. A. Zweerink
2000-10-17
The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) is located at the National Solar Thermal Test Facility of Sandia National Laboratories in Albuquerque, New Mexico, USA. The field of solar tracking mirrors (heliostats) around a central receiver tower is used to direct Cherenkov light from atmospheric showers onto secondary mirrors on the tower, which in turn image the light onto cameras of photomultiplier tubes. The STACEE Collaboration has previously reported a detection of the Crab Nebula with approximately 7 standard deviation significance, using 32 heliostats (STACEE-32). This result demonstrates both the viability of the technique and the suitability of the site. We are in the process of completing an upgrade to 48 heliostats (STACEE-48) en route to an eventual configuration using 64 heliostats (STACEE-64) in early 2001. In this paper, we summarize the results obtained on the sensitivity of STACEE-32 and our expectations for STACEE-48 and STACEE-64.
Improved detection of atmospheric turbulence with SLODAR
Michael Goodwin; Charles Jenkins; Andrew Lambert
2007-06-19
We discuss several improvements in the detection of atmospheric turbulence using SLOpe Detection And Ranging (SLODAR). Frequently, SLODAR observations have shown strong ground-layer turbulence, which is beneficial to adaptive optics. We show that current methods which neglect atmospheric propagation effects can underestimate the strength of high altitude turbulence by up to ~ 30%. We show that mirror and dome seeing turbulence can be a significant fraction of measured ground-layer turbulence, some cases up to ~ 50%. We also demonstrate a novel technique to improve the nominal height resolution, by a factor of 3, called Generalized SLODAR. This can be applied when sampling high-altitude turbulence, where the nominal height resolution is the poorest, or for resolving details in the important ground-layer.
Thermalisation of electrons in a stellar atmosphere
L. Chevallier
2006-01-23
We are interested in electrons kinetics in a stellar atmosphere to validate or invalidate the usually accepted hypothesis of thermalisation of electrons. For this purpose, we calculate the velocity distribution function of electrons by solving the kinetic equation of these particles together with the equations of radiative transfer and statistical equilibrium. We note that this distribution can deviate strongly from a Maxwell-Boltzmann distribution if non-LTE effects are important. Some results and astrophysical consequences are examined.
Atmospheric structure determined from satellite data
Knight, Keith Shelburne
1978-01-01
Subject: Meteorology ATM)SPHERIC STRUCTURE DETEiUIINED FRDM SATELLITE DATA A Thesis XEITH SHELBURNE KNIGHT Approved as to style and content. hyi (Chairman of Cor ' iee) C. (Head of Department) (Miemher) ABSTRACT Atmospheric Structure Determined... from Satellite Data. (August 1978) Keith Shelburne Knight, B. A. , University of California at Los Angeles Chairman of Advisory Conmittee: Dr. James R. Scoggins The capabilities of the Nimbus-6 satellite sounding data for use in synoptic analysis...
Pulsed atmospheric fluidized bed combustor apparatus
Mansour, Momtaz N. (Columbia, MD)
1993-10-26
A pulsed atmospheric fluidized bed reactor system is disclosed and claimed along with a process for utilization of same for the combustion of, e.g. high sulfur content coal. The system affords a economical, ecologically acceptable alternative to oil and gas fired combustors. The apparatus may also be employed for endothermic reaction, combustion of waste products, e.g., organic and medical waste, drying materials, heating air, calcining and the like.
Extraction of Freshwater and Energy from Atmosphere
Alexander Bolonkin
2007-04-19
Author offers and researches a new, cheap method for the extraction of freshwater from the Earth atmosphere. The suggected method is fundamentally dictinct from all existing methods that extract freshwater from air. All other industrial methods extract water from a saline water source (in most cases from seawater). This new method may be used at any point in the Earth except Polar Zones. It does not require long-distance freshwater transportation. If seawater is not utilized for increasing its productivity, this inexpensive new method is very environment-friendly. The author method has two working versions: (1) the first variant the warm (hot) atmospheric air is lifted by the inflatable tube in a high altitude and atmospheric steam is condenced into freswater: (2) in the second version, the warm air is pumped 20-30 meters under the sea-surface. In the first version, wind and solar heating of air are used for causing air flow. In version (2) wind and propeller are used for causing air movment. The first method does not need energy, the second needs a small amount. Moreover, in variant (1) the freshwater has a high pressure (>30 or more atm.) and can be used for production of energy such as electricity and in that way the freshwater cost is lower. For increasing the productivity the seawater is injected into air and solar air heater may be used. The solar air heater produces a huge amount of electricity as a very powerful electricity generation plant. The offered electricity installation in 100 - 200 times cheaper than any common electric plant of equivalent output. Key words: Extraction freshwater, method of getting freshwater, receiving energy from atmosphere, powerful renewal electric plant.
Romero Gomez, Pedro DJ; Richmond, Marshall C.
2014-04-17
Evaluating the consequences from blade-strike of fish on marine hydrokinetic (MHK) turbine blades is essential for incorporating environmental objectives into the integral optimization of machine performance. For instance, experience with conventional hydroelectric turbines has shown that innovative shaping of the blade and other machine components can lead to improved designs that generate more power without increased impacts to fish and other aquatic life. In this work, we used unsteady computational fluid dynamics (CFD) simulations of turbine flow and discrete element modeling (DEM) of particle motion to estimate the frequency and severity of collisions between a horizontal axis MHK tidal energy device and drifting aquatic organisms or debris. Two metrics are determined with the method: the strike frequency and survival rate estimate. To illustrate the procedure step-by-step, an exemplary case of a simple runner model was run and compared against a probabilistic model widely used for strike frequency evaluation. The results for the exemplary case showed a strong correlation between the two approaches. In the application case of the MHK turbine flow, turbulent flow was modeled using detached eddy simulation (DES) in conjunction with a full moving rotor at full scale. The CFD simulated power and thrust were satisfactorily comparable to experimental results conducted in a water tunnel on a reduced scaled (1:8.7) version of the turbine design. A cloud of DEM particles was injected into the domain to simulate fish or debris that were entrained into the turbine flow. The strike frequency was the ratio of the count of colliding particles to the crossing sample size. The fish length and approaching velocity were test conditions in the simulations of the MHK turbine. Comparisons showed that DEM-based frequencies tend to be greater than previous results from Lagrangian particles and probabilistic models, mostly because the DEM scheme accounts for both the geometric aspects of the passage event ---which the probabilistic method does--- as well as the fluid-particle interactions ---which the Lagrangian particle method does. The DEM-based survival rates were comparable to laboratory results for small fish but not for mid-size fish because of the considerably different turbine diameters. The modeling framework can be used for applications that aim at evaluating the biological performance of MHK turbine units during the design phase and to provide information to regulatory agencies needed for the environmental permitting process.
Shipboard Atmospheric O2 Measurements in the Southern Ocean
Stephens, Britton B.
outgassing on the atmospheric gradients at this latitude and time of year. This CO2 outgassing is in contrast
Extraction of Freshwater and Energy from Atmosphere
Bolonkin, Alexander
2007-01-01
Author offers and researches a new, cheap method for the extraction of freshwater from the Earth atmosphere. The suggected method is fundamentally dictinct from all existing methods that extract freshwater from air. All other industrial methods extract water from a saline water source (in most cases from seawater). This new method may be used at any point in the Earth except Polar Zones. It does not require long-distance freshwater transportation. If seawater is not utilized for increasing its productivity, this inexpensive new method is very environment-friendly. The author method has two working versions: (1) the first variant the warm (hot) atmospheric air is lifted by the inflatable tube in a high altitude and atmospheric steam is condenced into freswater: (2) in the second version, the warm air is pumped 20-30 meters under the sea-surface. In the first version, wind and solar heating of air are used for causing air flow. In version (2) wind and propeller are used for causing air movment. The first method...
Study of atmospheric pollution scavenging. [Annotated bibligraphy
Williams, A.L.
1990-08-01
Atmospheric scavenging research conducted by the Illinois State Water Survey under contract with the Department of Energy has been a significant factor in the historical development of the field of precipitation scavenging. Emphasis of the work during the 1980's became focused on the problem of acid rain problem with the Survey being chosen as the Central Analytical Laboratory for sample analysis of the National Atmospheric Deposition Program National Trends Network (NADP/NTN). The DOE research was responsible for laying the groundwork from the standpoint of sampling and chemical analysis that has now become routine features of NADP/NTN. A significant aspect of the research has been the participation by the Water Survey in the MAP3S precipitation sampling network which is totally supported by DOE, is the longest continuous precipitation sampling network in existence, and maintains an event sampling protocol. The following review consists of a short description of each of the papers appearing in the Study of Atmospheric Scavenging progress reports starting with the Eighteenth Progress Report in 1980 to the Twenty- Third Progress Report in 1989. In addition a listing of the significant publications and interviews associated with the program are given in the bibliography.
Large area atmospheric-pressure plasma jet
Selwyn, Gary S. (Los Alamos, NM); Henins, Ivars (Los Alamos, NM); Babayan, Steve E. (Huntington Beach, CA); Hicks, Robert F. (Los Angeles, CA)
2001-01-01
Large area atmospheric-pressure plasma jet. A plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 300 W, and shows distinct non-thermal characteristics. In the simplest design, two planar, parallel electrodes are employed to generate a plasma in the volume therebetween. A "jet" of long-lived metastable and reactive species that are capable of rapidly cleaning or etching metals and other materials is generated which extends up to 8 in. beyond the open end of the electrodes. Films and coatings may also be removed by these species. Arcing is prevented in the apparatus by using gas mixtures containing He, which limits ionization, by using high flow velocities, and by properly spacing the rf-powered electrode. Because of the atmospheric pressure operation, there is a negligible density of ions surviving for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike the situation for low-pressure plasma sources and conventional plasma processing methods.
Rapid Fluctuations in the Lower Solar Atmosphere
Lawrence, J K; Christian, D J; Jess, D B; Mathioudakis, M
2011-01-01
The Rapid Oscillations in the Solar Atmosphere (ROSA) instrument reveals solar atmospheric fluctuations at high frequencies. Spectra of variations of the G-band intensity (IG) and CaII K-line intensity (IK) show correlated fluctuations above white noise to frequencies beyond 300 mHz and 50 mHz, respectively. The noise-corrected G-band spectrum for f = 28 - 326 mHz shows a power law with exponent -1.21 \\pm, 0.02, consistent with the presence of turbulent motions. G-band spectral power in the 25 - 100 mHz ("UHF") range is concentrated at the locations of magnetic bright points in the intergranular lanes and is highly intermittent in time. The intermittence of the UHF G-band fluctuations, shown by a positive kurtosis {\\kappa}, also suggests turbulence. Combining values of IG, IK, UHF power, and {\\kappa}, reveals two distinct states of the solar atmosphere. State 1, including almost all the data, is characterized by low IG, IK, and UHF power and {\\kappa} \\approx 6. State 2, including only a very small fraction of...
Atmospheric and combustion chemistry of dimethyl ether
Nielsen, O.J.; Egsgaard, H.; Larsen, E.; Sehested, J.; Wallington, T.J.
1997-12-31
It has been demonstrated that dimethyl ether (DME) is an ideal diesel fuel alternative. DME, CH{sub 3}OCH{sub 3}, combines good fuel properties with low exhaust emissions and low combustion noise. Large scale production of this fuel can take place using a single step catalytic process converting CH{sub 4} to DME. The fate of DME in the atmosphere has previously been studied. The atmospheric degradation is initiated by the reaction with hydroxyl radicals, which is also a common feature of combustion processes. Spectrokinetic investigations and product analysis were used to demonstrate that the intermediate oxy radical, CH{sub 3}OCH{sub 2}O, exhibits a novel reaction pathway of hydrogen atom ejection. The application of tandem mass spectrometry to chemi-ions based on supersonic molecular beam sampling has recently been demonstrated. The highly reactive ionic intermediates are sampled directly from the flame and identified by collision activation mass spectrometry and ion-molecule reactions. The mass spectrum reflects the distribution of the intermediates in the flame. The atmospheric degradation of DME as well as the unique fuel properties of a oxygen containing compound will be discussed.
CPFFS Exhibit A General Conditions
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
General Conditions Page 29 of 33 (3) A least developed country (Afghanistan, Angola, Bangladesh, Benin, Bhutan, Burkina Faso, Burundi, Cambodia, Central African Republic, Chad,...
Atmospheric Chemistry of Venus-like Exoplanets Laura Schaefer
- 1 - Atmospheric Chemistry of Venus-like Exoplanets by Laura Schaefer and Bruce Fegley, Jr thermodynamic calculations to model atmospheric chemistry on terrestrial exoplanets that are hot enough for chemical equilibria between the atmosphere and lithosphere, as on Venus. The results of our calculations
Isotopic evidence for Mesoarchaean anoxia and changing atmospheric sulphur chemistry
Kaufman, Alan Jay
LETTERS Isotopic evidence for Mesoarchaean anoxia and changing atmospheric sulphur chemistry James changes in pre-2.45-Gyr-ago atmospheric pathways for non-mass-dependent chemistry and in the ultraviolet J. Kaufman1 The evolution of the Earth's atmosphere is marked by a transition from an early
Phase Transitions of Aqueous Atmospheric Particles Scot T. Martin*
Transformations of Polar Stratospheric Cloud Particles," in 1995-1996 at MIT in Atmospheric Chemistry. He was an Assistant Professor in Aquatic and Atmospheric Chemistry in the Department of Environmental Sciences and Engineers in the Atmospheric Chemistry Program). His laboratory research group is currently active in two
Renewed growth of atmospheric methane R. G. Prinn,1
use these data, along with an inverse method applied to a simple model of atmospheric chemistry this observation further using a simple model of atmospheric transport and chemistry to attempt to quantifyRenewed growth of atmospheric methane M. Rigby,1 R. G. Prinn,1 P. J. Fraser,2 P. G. Simmonds,3 R. L
Photo: RSMAS The Rosenstiel School of Marine and Atmospheric
, marine geophysics, ocean acoustics, and marine and atmospheric chemistry. The school is also known as onePhoto: RSMAS The Rosenstiel School of Marine and Atmospheric Science (RSMAS) was founded in 1943 in Biscayne Bay near Miami. It is the only subtropical applied and basic marine and atmospheric research
School of Earth and Atmospheric Sciences Georgia Institute of Technology
Wang, Yuhang
in atmospheric chemistry/air quality and climate and a growing reputation in oceanography, geophysicsSchool of Earth and Atmospheric Sciences Georgia Institute of Technology Strategic Plan March 1 opportunities. Vision The vision of the School of Earth and Atmospheric Sciences is: To lead in innovative
Usage Policies Notebook for Thermco Atmospheric Diffusion Furnace system
Mease, Kenneth D.
Usage Policies Notebook for Thermco Atmospheric Diffusion Furnace system Revision date September 2014 #12;2 Emergency Plan for Diffusion Furnaces Standard Operating Procedures for Emergencies Contact;4 Usage Policies for Thermco Atmospheric Diffusion Furnace Standard policies for usage The Atmospheric
High Altitude Unmanned Air System for Atmospheric Science Missions
Sóbester, András
High Altitude Unmanned Air System for Atmospheric Science Missions A. S´obester , S. J. Johnston and processing atmospheric observations across a range of altitudes. We consider the aeronautical a specified block of airspace. I. The Need for Wide Altitude Range Atmospheric Observations The ability
MEA 213 Introduction to Atmospheric Sciences I FALL Semester
Yuter, Sandra
and define the major terms that apply to meteorology. Structure of the atmosphere: Explain the chemical composition and vertical structure of the atmosphere. Weather maps: Read, interpret and plot station moisture parameter such as dew point, specific humidity, and mixing ratio from measured atmospheric
RESULTS FROM THE PHOENIX ATMOSPHERIC STRUCTURE PAUL WITHERS*,a
Withers, Paul
RESULTS FROM THE PHOENIX ATMOSPHERIC STRUCTURE EXPERIMENT PAUL WITHERS*,a AND DAVID C. CATLINGb through the atmosphere of Mars, Phoenix recorded acceleration and angular velocity data using the Experimental Data Records (EDRs) of the Phoenix Atmospheric Structure Experiment (ASE), are available from
Grenfell, John Lee; von Paris, Philip; Patzer, Beate; Lammer, Helmut; Stracke, Barbara; Gebauer, Stefanie; Schreier, Franz; Rauer, Heike
2015-01-01
Understanding whether M-dwarf stars may host habitable planets with Earth-like atmospheres and biospheres is a major goal in exoplanet research. If such planets exist, the question remains as to whether they could be identified via spectral signatures of biomarkers. Such planets may be exposed to extreme intensities of cosmic rays that could perturb their atmospheric photochemistry. Here, we consider stellar activity of M-dwarfs ranging from quiet up to strong flaring conditions and investigate one particular effect upon biomarkers, namely, the ability of secondary electrons caused by stellar cosmic rays to break up atmospheric molecular nitrogen (N2), which leads to production of nitrogen oxides in the planetary atmosphere, hence affecting biomarkers such as ozone. We apply a stationary model, that is, without a time-dependence, hence we are calculating the limiting case where the atmospheric chemistry response time of the biomarkers is assumed to be slow and remains constant compared with rapid forcing by t...
Prather, Michael J; Holmes, Christopher D; Hsu, Juno
2012-01-01
and time scales in atmospheric chemistry, Philos. Trans. R.PRATHER ET AL. : ATMOSPHERIC CHEMISTRY AND GREENHOUSE GASESet al. (2001), Atmospheric chemistry and greenhouse gases,
Liu, Yingdi
2011-01-01
modelling: a review. Atmospheric Chemistry and Physics,emerging issues. Atmospheric Chemistry and Physics, 2009. 9:aqueous phase. Atmospheric Chemistry and Physics, 2009. 9: